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linux/fs/btrfs/volumes.c
Qu Wenruo c57dd1f2f6 btrfs: trim: fix underflow in trim length to prevent access beyond device boundary 
[BUG]
The following script can lead to tons of beyond device boundary access:

  mkfs.btrfs -f $dev -b 10G
  mount $dev $mnt
  trimfs $mnt
  btrfs filesystem resize 1:-1G $mnt
  trimfs $mnt

[CAUSE]
Since commit 929be17a9b ("btrfs: Switch btrfs_trim_free_extents to
find_first_clear_extent_bit"), we try to avoid trimming ranges that's
already trimmed.

So we check device->alloc_state by finding the first range which doesn't
have CHUNK_TRIMMED and CHUNK_ALLOCATED not set.

But if we shrunk the device, that bits are not cleared, thus we could
easily got a range starts beyond the shrunk device size.

This results the returned @start and @end are all beyond device size,
then we call "end = min(end, device->total_bytes -1);" making @end
smaller than device size.

Then finally we goes "len = end - start + 1", totally underflow the
result, and lead to the beyond-device-boundary access.

[FIX]
This patch will fix the problem in two ways:

- Clear CHUNK_TRIMMED | CHUNK_ALLOCATED bits when shrinking device
  This is the root fix

- Add extra safety check when trimming free device extents
  We check and warn if the returned range is already beyond current
  device.

Link: https://github.com/kdave/btrfs-progs/issues/282
Fixes: 929be17a9b ("btrfs: Switch btrfs_trim_free_extents to find_first_clear_extent_bit")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-08-12 10:15:58 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/semaphore.h>
#include <linux/uuid.h>
#include <linux/list_sort.h>
#include "misc.h"
#include "ctree.h"
#include "extent_map.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
#include "raid56.h"
#include "async-thread.h"
#include "check-integrity.h"
#include "rcu-string.h"
#include "dev-replace.h"
#include "sysfs.h"
#include "tree-checker.h"
#include "space-info.h"
#include "block-group.h"
#include "discard.h"
const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = {
.sub_stripes = 2,
.dev_stripes = 1,
.devs_max = 0, /* 0 == as many as possible */
.devs_min = 4,
.tolerated_failures = 1,
.devs_increment = 2,
.ncopies = 2,
.nparity = 0,
.raid_name = "raid10",
.bg_flag = BTRFS_BLOCK_GROUP_RAID10,
.mindev_error = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 2,
.devs_min = 2,
.tolerated_failures = 1,
.devs_increment = 2,
.ncopies = 2,
.nparity = 0,
.raid_name = "raid1",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1,
.mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1C3] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 3,
.devs_min = 3,
.tolerated_failures = 2,
.devs_increment = 3,
.ncopies = 3,
.nparity = 0,
.raid_name = "raid1c3",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1C3,
.mindev_error = BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1C4] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 4,
.devs_min = 4,
.tolerated_failures = 3,
.devs_increment = 4,
.ncopies = 4,
.nparity = 0,
.raid_name = "raid1c4",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1C4,
.mindev_error = BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
},
[BTRFS_RAID_DUP] = {
.sub_stripes = 1,
.dev_stripes = 2,
.devs_max = 1,
.devs_min = 1,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 2,
.nparity = 0,
.raid_name = "dup",
.bg_flag = BTRFS_BLOCK_GROUP_DUP,
.mindev_error = 0,
},
[BTRFS_RAID_RAID0] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 2,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 1,
.nparity = 0,
.raid_name = "raid0",
.bg_flag = BTRFS_BLOCK_GROUP_RAID0,
.mindev_error = 0,
},
[BTRFS_RAID_SINGLE] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 1,
.devs_min = 1,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 1,
.nparity = 0,
.raid_name = "single",
.bg_flag = 0,
.mindev_error = 0,
},
[BTRFS_RAID_RAID5] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 2,
.tolerated_failures = 1,
.devs_increment = 1,
.ncopies = 1,
.nparity = 1,
.raid_name = "raid5",
.bg_flag = BTRFS_BLOCK_GROUP_RAID5,
.mindev_error = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
},
[BTRFS_RAID_RAID6] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 3,
.tolerated_failures = 2,
.devs_increment = 1,
.ncopies = 1,
.nparity = 2,
.raid_name = "raid6",
.bg_flag = BTRFS_BLOCK_GROUP_RAID6,
.mindev_error = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
},
};
const char *btrfs_bg_type_to_raid_name(u64 flags)
{
const int index = btrfs_bg_flags_to_raid_index(flags);
if (index >= BTRFS_NR_RAID_TYPES)
return NULL;
return btrfs_raid_array[index].raid_name;
}
/*
* Fill @buf with textual description of @bg_flags, no more than @size_buf
* bytes including terminating null byte.
*/
void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf)
{
int i;
int ret;
char *bp = buf;
u64 flags = bg_flags;
u32 size_bp = size_buf;
if (!flags) {
strcpy(bp, "NONE");
return;
}
#define DESCRIBE_FLAG(flag, desc) \
do { \
if (flags & (flag)) { \
ret = snprintf(bp, size_bp, "%s|", (desc)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
flags &= ~(flag); \
} \
} while (0)
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data");
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system");
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata");
DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single");
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
DESCRIBE_FLAG(btrfs_raid_array[i].bg_flag,
btrfs_raid_array[i].raid_name);
#undef DESCRIBE_FLAG
if (flags) {
ret = snprintf(bp, size_bp, "0x%llx|", flags);
size_bp -= ret;
}
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last | */
/*
* The text is trimmed, it's up to the caller to provide sufficiently
* large buffer
*/
out_overflow:;
}
static int init_first_rw_device(struct btrfs_trans_handle *trans);
static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret,
int mirror_num, int need_raid_map);
/*
* Device locking
* ==============
*
* There are several mutexes that protect manipulation of devices and low-level
* structures like chunks but not block groups, extents or files
*
* uuid_mutex (global lock)
* ------------------------
* protects the fs_uuids list that tracks all per-fs fs_devices, resulting from
* the SCAN_DEV ioctl registration or from mount either implicitly (the first
* device) or requested by the device= mount option
*
* the mutex can be very coarse and can cover long-running operations
*
* protects: updates to fs_devices counters like missing devices, rw devices,
* seeding, structure cloning, opening/closing devices at mount/umount time
*
* global::fs_devs - add, remove, updates to the global list
*
* does not protect: manipulation of the fs_devices::devices list in general
* but in mount context it could be used to exclude list modifications by eg.
* scan ioctl
*
* btrfs_device::name - renames (write side), read is RCU
*
* fs_devices::device_list_mutex (per-fs, with RCU)
* ------------------------------------------------
* protects updates to fs_devices::devices, ie. adding and deleting
*
* simple list traversal with read-only actions can be done with RCU protection
*
* may be used to exclude some operations from running concurrently without any
* modifications to the list (see write_all_supers)
*
* Is not required at mount and close times, because our device list is
* protected by the uuid_mutex at that point.
*
* balance_mutex
* -------------
* protects balance structures (status, state) and context accessed from
* several places (internally, ioctl)
*
* chunk_mutex
* -----------
* protects chunks, adding or removing during allocation, trim or when a new
* device is added/removed. Additionally it also protects post_commit_list of
* individual devices, since they can be added to the transaction's
* post_commit_list only with chunk_mutex held.
*
* cleaner_mutex
* -------------
* a big lock that is held by the cleaner thread and prevents running subvolume
* cleaning together with relocation or delayed iputs
*
*
* Lock nesting
* ============
*
* uuid_mutex
* device_list_mutex
* chunk_mutex
* balance_mutex
*
*
* Exclusive operations, BTRFS_FS_EXCL_OP
* ======================================
*
* Maintains the exclusivity of the following operations that apply to the
* whole filesystem and cannot run in parallel.
*
* - Balance (*)
* - Device add
* - Device remove
* - Device replace (*)
* - Resize
*
* The device operations (as above) can be in one of the following states:
*
* - Running state
* - Paused state
* - Completed state
*
* Only device operations marked with (*) can go into the Paused state for the
* following reasons:
*
* - ioctl (only Balance can be Paused through ioctl)
* - filesystem remounted as read-only
* - filesystem unmounted and mounted as read-only
* - system power-cycle and filesystem mounted as read-only
* - filesystem or device errors leading to forced read-only
*
* BTRFS_FS_EXCL_OP flag is set and cleared using atomic operations.
* During the course of Paused state, the BTRFS_FS_EXCL_OP remains set.
* A device operation in Paused or Running state can be canceled or resumed
* either by ioctl (Balance only) or when remounted as read-write.
* BTRFS_FS_EXCL_OP flag is cleared when the device operation is canceled or
* completed.
*/
DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
struct list_head * __attribute_const__ btrfs_get_fs_uuids(void)
{
return &fs_uuids;
}
/*
* alloc_fs_devices - allocate struct btrfs_fs_devices
* @fsid: if not NULL, copy the UUID to fs_devices::fsid
* @metadata_fsid: if not NULL, copy the UUID to fs_devices::metadata_fsid
*
* Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR().
* The returned struct is not linked onto any lists and can be destroyed with
* kfree() right away.
*/
static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid,
const u8 *metadata_fsid)
{
struct btrfs_fs_devices *fs_devs;
fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL);
if (!fs_devs)
return ERR_PTR(-ENOMEM);
mutex_init(&fs_devs->device_list_mutex);
INIT_LIST_HEAD(&fs_devs->devices);
INIT_LIST_HEAD(&fs_devs->alloc_list);
INIT_LIST_HEAD(&fs_devs->fs_list);
if (fsid)
memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
if (metadata_fsid)
memcpy(fs_devs->metadata_uuid, metadata_fsid, BTRFS_FSID_SIZE);
else if (fsid)
memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE);
return fs_devs;
}
void btrfs_free_device(struct btrfs_device *device)
{
WARN_ON(!list_empty(&device->post_commit_list));
rcu_string_free(device->name);
extent_io_tree_release(&device->alloc_state);
bio_put(device->flush_bio);
kfree(device);
}
static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
WARN_ON(fs_devices->opened);
while (!list_empty(&fs_devices->devices)) {
device = list_entry(fs_devices->devices.next,
struct btrfs_device, dev_list);
list_del(&device->dev_list);
btrfs_free_device(device);
}
kfree(fs_devices);
}
void __exit btrfs_cleanup_fs_uuids(void)
{
struct btrfs_fs_devices *fs_devices;
while (!list_empty(&fs_uuids)) {
fs_devices = list_entry(fs_uuids.next,
struct btrfs_fs_devices, fs_list);
list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
/*
* Returns a pointer to a new btrfs_device on success; ERR_PTR() on error.
* Returned struct is not linked onto any lists and must be destroyed using
* btrfs_free_device.
*/
static struct btrfs_device *__alloc_device(void)
{
struct btrfs_device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return ERR_PTR(-ENOMEM);
/*
* Preallocate a bio that's always going to be used for flushing device
* barriers and matches the device lifespan
*/
dev->flush_bio = bio_alloc_bioset(GFP_KERNEL, 0, NULL);
if (!dev->flush_bio) {
kfree(dev);
return ERR_PTR(-ENOMEM);
}
INIT_LIST_HEAD(&dev->dev_list);
INIT_LIST_HEAD(&dev->dev_alloc_list);
INIT_LIST_HEAD(&dev->post_commit_list);
atomic_set(&dev->reada_in_flight, 0);
atomic_set(&dev->dev_stats_ccnt, 0);
btrfs_device_data_ordered_init(dev);
INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
extent_io_tree_init(NULL, &dev->alloc_state, 0, NULL);
return dev;
}
static noinline struct btrfs_fs_devices *find_fsid(
const u8 *fsid, const u8 *metadata_fsid)
{
struct btrfs_fs_devices *fs_devices;
ASSERT(fsid);
/* Handle non-split brain cases */
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (metadata_fsid) {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
&& memcmp(metadata_fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0)
return fs_devices;
} else {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handle scanned device having completed its fsid change but
* belonging to a fs_devices that was created by first scanning
* a device which didn't have its fsid/metadata_uuid changed
* at all and the CHANGING_FSID_V2 flag set.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (fs_devices->fsid_change &&
memcmp(disk_super->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0) {
return fs_devices;
}
}
/*
* Handle scanned device having completed its fsid change but
* belonging to a fs_devices that was created by a device that
* has an outdated pair of fsid/metadata_uuid and
* CHANGING_FSID_V2 flag set.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (fs_devices->fsid_change &&
memcmp(fs_devices->metadata_uuid,
fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0) {
return fs_devices;
}
}
return find_fsid(disk_super->fsid, disk_super->metadata_uuid);
}
static int
btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
int flush, struct block_device **bdev,
struct btrfs_super_block **disk_super)
{
int ret;
*bdev = blkdev_get_by_path(device_path, flags, holder);
if (IS_ERR(*bdev)) {
ret = PTR_ERR(*bdev);
goto error;
}
if (flush)
filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
if (ret) {
blkdev_put(*bdev, flags);
goto error;
}
invalidate_bdev(*bdev);
*disk_super = btrfs_read_dev_super(*bdev);
if (IS_ERR(*disk_super)) {
ret = PTR_ERR(*disk_super);
blkdev_put(*bdev, flags);
goto error;
}
return 0;
error:
*bdev = NULL;
return ret;
}
static bool device_path_matched(const char *path, struct btrfs_device *device)
{
int found;
rcu_read_lock();
found = strcmp(rcu_str_deref(device->name), path);
rcu_read_unlock();
return found == 0;
}
/*
* Search and remove all stale (devices which are not mounted) devices.
* When both inputs are NULL, it will search and release all stale devices.
* path: Optional. When provided will it release all unmounted devices
* matching this path only.
* skip_dev: Optional. Will skip this device when searching for the stale
* devices.
* Return: 0 for success or if @path is NULL.
* -EBUSY if @path is a mounted device.
* -ENOENT if @path does not match any device in the list.
*/
static int btrfs_free_stale_devices(const char *path,
struct btrfs_device *skip_device)
{
struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
struct btrfs_device *device, *tmp_device;
int ret = 0;
if (path)
ret = -ENOENT;
list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, tmp_device,
&fs_devices->devices, dev_list) {
if (skip_device && skip_device == device)
continue;
if (path && !device->name)
continue;
if (path && !device_path_matched(path, device))
continue;
if (fs_devices->opened) {
/* for an already deleted device return 0 */
if (path && ret != 0)
ret = -EBUSY;
break;
}
/* delete the stale device */
fs_devices->num_devices--;
list_del(&device->dev_list);
btrfs_free_device(device);
ret = 0;
if (fs_devices->num_devices == 0)
break;
}
mutex_unlock(&fs_devices->device_list_mutex);
if (fs_devices->num_devices == 0) {
btrfs_sysfs_remove_fsid(fs_devices);
list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
return ret;
}
/*
* This is only used on mount, and we are protected from competing things
* messing with our fs_devices by the uuid_mutex, thus we do not need the
* fs_devices->device_list_mutex here.
*/
static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *device, fmode_t flags,
void *holder)
{
struct request_queue *q;
struct block_device *bdev;
struct btrfs_super_block *disk_super;
u64 devid;
int ret;
if (device->bdev)
return -EINVAL;
if (!device->name)
return -EINVAL;
ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
&bdev, &disk_super);
if (ret)
return ret;
devid = btrfs_stack_device_id(&disk_super->dev_item);
if (devid != device->devid)
goto error_free_page;
if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE))
goto error_free_page;
device->generation = btrfs_super_generation(disk_super);
if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
if (btrfs_super_incompat_flags(disk_super) &
BTRFS_FEATURE_INCOMPAT_METADATA_UUID) {
pr_err(
"BTRFS: Invalid seeding and uuid-changed device detected\n");
goto error_free_page;
}
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
fs_devices->seeding = true;
} else {
if (bdev_read_only(bdev))
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
else
set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
}
q = bdev_get_queue(bdev);
if (!blk_queue_nonrot(q))
fs_devices->rotating = true;
device->bdev = bdev;
clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
device->mode = flags;
fs_devices->open_devices++;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
device->devid != BTRFS_DEV_REPLACE_DEVID) {
fs_devices->rw_devices++;
list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list);
}
btrfs_release_disk_super(disk_super);
return 0;
error_free_page:
btrfs_release_disk_super(disk_super);
blkdev_put(bdev, flags);
return -EINVAL;
}
/*
* Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
* being created with a disk that has already completed its fsid change. Such
* disk can belong to an fs which has its FSID changed or to one which doesn't.
* Handle both cases here.
*/
static struct btrfs_fs_devices *find_fsid_inprogress(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->fsid,
BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {
return fs_devices;
}
}
return find_fsid(disk_super->fsid, NULL);
}
static struct btrfs_fs_devices *find_fsid_changed(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handles the case where scanned device is part of an fs that had
* multiple successful changes of FSID but curently device didn't
* observe it. Meaning our fsid will be different than theirs. We need
* to handle two subcases :
* 1 - The fs still continues to have different METADATA/FSID uuids.
* 2 - The fs is switched back to its original FSID (METADATA/FSID
* are equal).
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
/* Changed UUIDs */
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, disk_super->fsid,
BTRFS_FSID_SIZE) != 0)
return fs_devices;
/* Unchanged UUIDs */
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, disk_super->metadata_uuid,
BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid_reverted_metadata(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handle the case where the scanned device is part of an fs whose last
* metadata UUID change reverted it to the original FSID. At the same
* time * fs_devices was first created by another constitutent device
* which didn't fully observe the operation. This results in an
* btrfs_fs_devices created with metadata/fsid different AND
* btrfs_fs_devices::fsid_change set AND the metadata_uuid of the
* fs_devices equal to the FSID of the disk.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->fsid,
BTRFS_FSID_SIZE) == 0 &&
fs_devices->fsid_change)
return fs_devices;
}
return NULL;
}
/*
* Add new device to list of registered devices
*
* Returns:
* device pointer which was just added or updated when successful
* error pointer when failed
*/
static noinline struct btrfs_device *device_list_add(const char *path,
struct btrfs_super_block *disk_super,
bool *new_device_added)
{
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices = NULL;
struct rcu_string *name;
u64 found_transid = btrfs_super_generation(disk_super);
u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) &
BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
bool fsid_change_in_progress = (btrfs_super_flags(disk_super) &
BTRFS_SUPER_FLAG_CHANGING_FSID_V2);
if (fsid_change_in_progress) {
if (!has_metadata_uuid)
fs_devices = find_fsid_inprogress(disk_super);
else
fs_devices = find_fsid_changed(disk_super);
} else if (has_metadata_uuid) {
fs_devices = find_fsid_with_metadata_uuid(disk_super);
} else {
fs_devices = find_fsid_reverted_metadata(disk_super);
if (!fs_devices)
fs_devices = find_fsid(disk_super->fsid, NULL);
}
if (!fs_devices) {
if (has_metadata_uuid)
fs_devices = alloc_fs_devices(disk_super->fsid,
disk_super->metadata_uuid);
else
fs_devices = alloc_fs_devices(disk_super->fsid, NULL);
if (IS_ERR(fs_devices))
return ERR_CAST(fs_devices);
fs_devices->fsid_change = fsid_change_in_progress;
mutex_lock(&fs_devices->device_list_mutex);
list_add(&fs_devices->fs_list, &fs_uuids);
device = NULL;
} else {
mutex_lock(&fs_devices->device_list_mutex);
device = btrfs_find_device(fs_devices, devid,
disk_super->dev_item.uuid, NULL, false);
/*
* If this disk has been pulled into an fs devices created by
* a device which had the CHANGING_FSID_V2 flag then replace the
* metadata_uuid/fsid values of the fs_devices.
*/
if (fs_devices->fsid_change &&
found_transid > fs_devices->latest_generation) {
memcpy(fs_devices->fsid, disk_super->fsid,
BTRFS_FSID_SIZE);
if (has_metadata_uuid)
memcpy(fs_devices->metadata_uuid,
disk_super->metadata_uuid,
BTRFS_FSID_SIZE);
else
memcpy(fs_devices->metadata_uuid,
disk_super->fsid, BTRFS_FSID_SIZE);
fs_devices->fsid_change = false;
}
}
if (!device) {
if (fs_devices->opened) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-EBUSY);
}
device = btrfs_alloc_device(NULL, &devid,
disk_super->dev_item.uuid);
if (IS_ERR(device)) {
mutex_unlock(&fs_devices->device_list_mutex);
/* we can safely leave the fs_devices entry around */
return device;
}
name = rcu_string_strdup(path, GFP_NOFS);
if (!name) {
btrfs_free_device(device);
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-ENOMEM);
}
rcu_assign_pointer(device->name, name);
list_add_rcu(&device->dev_list, &fs_devices->devices);
fs_devices->num_devices++;
device->fs_devices = fs_devices;
*new_device_added = true;
if (disk_super->label[0])
pr_info(
"BTRFS: device label %s devid %llu transid %llu %s scanned by %s (%d)\n",
disk_super->label, devid, found_transid, path,
current->comm, task_pid_nr(current));
else
pr_info(
"BTRFS: device fsid %pU devid %llu transid %llu %s scanned by %s (%d)\n",
disk_super->fsid, devid, found_transid, path,
current->comm, task_pid_nr(current));
} else if (!device->name || strcmp(device->name->str, path)) {
/*
* When FS is already mounted.
* 1. If you are here and if the device->name is NULL that
* means this device was missing at time of FS mount.
* 2. If you are here and if the device->name is different
* from 'path' that means either
* a. The same device disappeared and reappeared with
* different name. or
* b. The missing-disk-which-was-replaced, has
* reappeared now.
*
* We must allow 1 and 2a above. But 2b would be a spurious
* and unintentional.
*
* Further in case of 1 and 2a above, the disk at 'path'
* would have missed some transaction when it was away and
* in case of 2a the stale bdev has to be updated as well.
* 2b must not be allowed at all time.
*/
/*
* For now, we do allow update to btrfs_fs_device through the
* btrfs dev scan cli after FS has been mounted. We're still
* tracking a problem where systems fail mount by subvolume id
* when we reject replacement on a mounted FS.
*/
if (!fs_devices->opened && found_transid < device->generation) {
/*
* That is if the FS is _not_ mounted and if you
* are here, that means there is more than one
* disk with same uuid and devid.We keep the one
* with larger generation number or the last-in if
* generation are equal.
*/
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-EEXIST);
}
/*
* We are going to replace the device path for a given devid,
* make sure it's the same device if the device is mounted
*/
if (device->bdev) {
struct block_device *path_bdev;
path_bdev = lookup_bdev(path);
if (IS_ERR(path_bdev)) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_CAST(path_bdev);
}
if (device->bdev != path_bdev) {
bdput(path_bdev);
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_warn_in_rcu(device->fs_info,
"duplicate device fsid:devid for %pU:%llu old:%s new:%s",
disk_super->fsid, devid,
rcu_str_deref(device->name), path);
return ERR_PTR(-EEXIST);
}
bdput(path_bdev);
btrfs_info_in_rcu(device->fs_info,
"device fsid %pU devid %llu moved old:%s new:%s",
disk_super->fsid, devid,
rcu_str_deref(device->name), path);
}
name = rcu_string_strdup(path, GFP_NOFS);
if (!name) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-ENOMEM);
}
rcu_string_free(device->name);
rcu_assign_pointer(device->name, name);
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
fs_devices->missing_devices--;
clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
}
}
/*
* Unmount does not free the btrfs_device struct but would zero
* generation along with most of the other members. So just update
* it back. We need it to pick the disk with largest generation
* (as above).
*/
if (!fs_devices->opened) {
device->generation = found_transid;
fs_devices->latest_generation = max_t(u64, found_transid,
fs_devices->latest_generation);
}
fs_devices->total_devices = btrfs_super_num_devices(disk_super);
mutex_unlock(&fs_devices->device_list_mutex);
return device;
}
static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
{
struct btrfs_fs_devices *fs_devices;
struct btrfs_device *device;
struct btrfs_device *orig_dev;
int ret = 0;
fs_devices = alloc_fs_devices(orig->fsid, NULL);
if (IS_ERR(fs_devices))
return fs_devices;
mutex_lock(&orig->device_list_mutex);
fs_devices->total_devices = orig->total_devices;
list_for_each_entry(orig_dev, &orig->devices, dev_list) {
struct rcu_string *name;
device = btrfs_alloc_device(NULL, &orig_dev->devid,
orig_dev->uuid);
if (IS_ERR(device)) {
ret = PTR_ERR(device);
goto error;
}
/*
* This is ok to do without rcu read locked because we hold the
* uuid mutex so nothing we touch in here is going to disappear.
*/
if (orig_dev->name) {
name = rcu_string_strdup(orig_dev->name->str,
GFP_KERNEL);
if (!name) {
btrfs_free_device(device);
ret = -ENOMEM;
goto error;
}
rcu_assign_pointer(device->name, name);
}
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
}
mutex_unlock(&orig->device_list_mutex);
return fs_devices;
error:
mutex_unlock(&orig->device_list_mutex);
free_fs_devices(fs_devices);
return ERR_PTR(ret);
}
/*
* After we have read the system tree and know devids belonging to
* this filesystem, remove the device which does not belong there.
*/
void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step)
{
struct btrfs_device *device, *next;
struct btrfs_device *latest_dev = NULL;
mutex_lock(&uuid_mutex);
again:
/* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state)) {
if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state) &&
!test_bit(BTRFS_DEV_STATE_MISSING,
&device->dev_state) &&
(!latest_dev ||
device->generation > latest_dev->generation)) {
latest_dev = device;
}
continue;
}
if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
/*
* In the first step, keep the device which has
* the correct fsid and the devid that is used
* for the dev_replace procedure.
* In the second step, the dev_replace state is
* read from the device tree and it is known
* whether the procedure is really active or
* not, which means whether this device is
* used or whether it should be removed.
*/
if (step == 0 || test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state)) {
continue;
}
}
if (device->bdev) {
blkdev_put(device->bdev, device->mode);
device->bdev = NULL;
fs_devices->open_devices--;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
list_del_init(&device->dev_alloc_list);
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state))
fs_devices->rw_devices--;
}
list_del_init(&device->dev_list);
fs_devices->num_devices--;
btrfs_free_device(device);
}
if (fs_devices->seed) {
fs_devices = fs_devices->seed;
goto again;
}
fs_devices->latest_bdev = latest_dev->bdev;
mutex_unlock(&uuid_mutex);
}
static void btrfs_close_bdev(struct btrfs_device *device)
{
if (!device->bdev)
return;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
sync_blockdev(device->bdev);
invalidate_bdev(device->bdev);
}
blkdev_put(device->bdev, device->mode);
}
static void btrfs_close_one_device(struct btrfs_device *device)
{
struct btrfs_fs_devices *fs_devices = device->fs_devices;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
device->devid != BTRFS_DEV_REPLACE_DEVID) {
list_del_init(&device->dev_alloc_list);
fs_devices->rw_devices--;
}
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
fs_devices->missing_devices--;
btrfs_close_bdev(device);
if (device->bdev) {
fs_devices->open_devices--;
device->bdev = NULL;
}
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
device->fs_info = NULL;
atomic_set(&device->dev_stats_ccnt, 0);
extent_io_tree_release(&device->alloc_state);
/* Verify the device is back in a pristine state */
ASSERT(!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state));
ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
ASSERT(list_empty(&device->dev_alloc_list));
ASSERT(list_empty(&device->post_commit_list));
ASSERT(atomic_read(&device->reada_in_flight) == 0);
}
static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device, *tmp;
if (--fs_devices->opened > 0)
return 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
btrfs_close_one_device(device);
}
mutex_unlock(&fs_devices->device_list_mutex);
WARN_ON(fs_devices->open_devices);
WARN_ON(fs_devices->rw_devices);
fs_devices->opened = 0;
fs_devices->seeding = false;
return 0;
}
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_fs_devices *seed_devices = NULL;
int ret;
mutex_lock(&uuid_mutex);
ret = close_fs_devices(fs_devices);
if (!fs_devices->opened) {
seed_devices = fs_devices->seed;
fs_devices->seed = NULL;
}
mutex_unlock(&uuid_mutex);
while (seed_devices) {
fs_devices = seed_devices;
seed_devices = fs_devices->seed;
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
return ret;
}
static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
struct btrfs_device *device;
struct btrfs_device *latest_dev = NULL;
flags |= FMODE_EXCL;
list_for_each_entry(device, &fs_devices->devices, dev_list) {
/* Just open everything we can; ignore failures here */
if (btrfs_open_one_device(fs_devices, device, flags, holder))
continue;
if (!latest_dev ||
device->generation > latest_dev->generation)
latest_dev = device;
}
if (fs_devices->open_devices == 0)
return -EINVAL;
fs_devices->opened = 1;
fs_devices->latest_bdev = latest_dev->bdev;
fs_devices->total_rw_bytes = 0;
fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR;
return 0;
}
static int devid_cmp(void *priv, struct list_head *a, struct list_head *b)
{
struct btrfs_device *dev1, *dev2;
dev1 = list_entry(a, struct btrfs_device, dev_list);
dev2 = list_entry(b, struct btrfs_device, dev_list);
if (dev1->devid < dev2->devid)
return -1;
else if (dev1->devid > dev2->devid)
return 1;
return 0;
}
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
int ret;
lockdep_assert_held(&uuid_mutex);
/*
* The device_list_mutex cannot be taken here in case opening the
* underlying device takes further locks like bd_mutex.
*
* We also don't need the lock here as this is called during mount and
* exclusion is provided by uuid_mutex
*/
if (fs_devices->opened) {
fs_devices->opened++;
ret = 0;
} else {
list_sort(NULL, &fs_devices->devices, devid_cmp);
ret = open_fs_devices(fs_devices, flags, holder);
}
return ret;
}
void btrfs_release_disk_super(struct btrfs_super_block *super)
{
struct page *page = virt_to_page(super);
put_page(page);
}
static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
u64 bytenr)
{
struct btrfs_super_block *disk_super;
struct page *page;
void *p;
pgoff_t index;
/* make sure our super fits in the device */
if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
return ERR_PTR(-EINVAL);
/* make sure our super fits in the page */
if (sizeof(*disk_super) > PAGE_SIZE)
return ERR_PTR(-EINVAL);
/* make sure our super doesn't straddle pages on disk */
index = bytenr >> PAGE_SHIFT;
if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_SHIFT != index)
return ERR_PTR(-EINVAL);
/* pull in the page with our super */
page = read_cache_page_gfp(bdev->bd_inode->i_mapping, index, GFP_KERNEL);
if (IS_ERR(page))
return ERR_CAST(page);
p = page_address(page);
/* align our pointer to the offset of the super block */
disk_super = p + offset_in_page(bytenr);
if (btrfs_super_bytenr(disk_super) != bytenr ||
btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
btrfs_release_disk_super(p);
return ERR_PTR(-EINVAL);
}
if (disk_super->label[0] && disk_super->label[BTRFS_LABEL_SIZE - 1])
disk_super->label[BTRFS_LABEL_SIZE - 1] = 0;
return disk_super;
}
int btrfs_forget_devices(const char *path)
{
int ret;
mutex_lock(&uuid_mutex);
ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL);
mutex_unlock(&uuid_mutex);
return ret;
}
/*
* Look for a btrfs signature on a device. This may be called out of the mount path
* and we are not allowed to call set_blocksize during the scan. The superblock
* is read via pagecache
*/
struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
void *holder)
{
struct btrfs_super_block *disk_super;
bool new_device_added = false;
struct btrfs_device *device = NULL;
struct block_device *bdev;
u64 bytenr;
lockdep_assert_held(&uuid_mutex);
/*
* we would like to check all the supers, but that would make
* a btrfs mount succeed after a mkfs from a different FS.
* So, we need to add a special mount option to scan for
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
bytenr = btrfs_sb_offset(0);
flags |= FMODE_EXCL;
bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
disk_super = btrfs_read_disk_super(bdev, bytenr);
if (IS_ERR(disk_super)) {
device = ERR_CAST(disk_super);
goto error_bdev_put;
}
device = device_list_add(path, disk_super, &new_device_added);
if (!IS_ERR(device)) {
if (new_device_added)
btrfs_free_stale_devices(path, device);
}
btrfs_release_disk_super(disk_super);
error_bdev_put:
blkdev_put(bdev, flags);
return device;
}
/*
* Try to find a chunk that intersects [start, start + len] range and when one
* such is found, record the end of it in *start
*/
static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
u64 len)
{
u64 physical_start, physical_end;
lockdep_assert_held(&device->fs_info->chunk_mutex);
if (!find_first_extent_bit(&device->alloc_state, *start,
&physical_start, &physical_end,
CHUNK_ALLOCATED, NULL)) {
if (in_range(physical_start, *start, len) ||
in_range(*start, physical_start,
physical_end - physical_start)) {
*start = physical_end + 1;
return true;
}
}
return false;
}
static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
{
switch (device->fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
/*
* We don't want to overwrite the superblock on the drive nor
* any area used by the boot loader (grub for example), so we
* make sure to start at an offset of at least 1MB.
*/
return max_t(u64, start, SZ_1M);
default:
BUG();
}
}
/**
* dev_extent_hole_check - check if specified hole is suitable for allocation
* @device: the device which we have the hole
* @hole_start: starting position of the hole
* @hole_size: the size of the hole
* @num_bytes: the size of the free space that we need
*
* This function may modify @hole_start and @hole_end to reflect the suitable
* position for allocation. Returns 1 if hole position is updated, 0 otherwise.
*/
static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
u64 *hole_size, u64 num_bytes)
{
bool changed = false;
u64 hole_end = *hole_start + *hole_size;
/*
* Check before we set max_hole_start, otherwise we could end up
* sending back this offset anyway.
*/
if (contains_pending_extent(device, hole_start, *hole_size)) {
if (hole_end >= *hole_start)
*hole_size = hole_end - *hole_start;
else
*hole_size = 0;
changed = true;
}
switch (device->fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
/* No extra check */
break;
default:
BUG();
}
return changed;
}
/*
* find_free_dev_extent_start - find free space in the specified device
* @device: the device which we search the free space in
* @num_bytes: the size of the free space that we need
* @search_start: the position from which to begin the search
* @start: store the start of the free space.
* @len: the size of the free space. that we find, or the size
* of the max free space if we don't find suitable free space
*
* this uses a pretty simple search, the expectation is that it is
* called very infrequently and that a given device has a small number
* of extents
*
* @start is used to store the start of the free space if we find. But if we
* don't find suitable free space, it will be used to store the start position
* of the max free space.
*
* @len is used to store the size of the free space that we find.
* But if we don't find suitable free space, it is used to store the size of
* the max free space.
*
* NOTE: This function will search *commit* root of device tree, and does extra
* check to ensure dev extents are not double allocated.
* This makes the function safe to allocate dev extents but may not report
* correct usable device space, as device extent freed in current transaction
* is not reported as avaiable.
*/
static int find_free_dev_extent_start(struct btrfs_device *device,
u64 num_bytes, u64 search_start, u64 *start,
u64 *len)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_key key;
struct btrfs_dev_extent *dev_extent;
struct btrfs_path *path;
u64 hole_size;
u64 max_hole_start;
u64 max_hole_size;
u64 extent_end;
u64 search_end = device->total_bytes;
int ret;
int slot;
struct extent_buffer *l;
search_start = dev_extent_search_start(device, search_start);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
max_hole_start = search_start;
max_hole_size = 0;
again:
if (search_start >= search_end ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = -ENOSPC;
goto out;
}
path->reada = READA_FORWARD;
path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = device->devid;
key.offset = search_start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid, key.type);
if (ret < 0)
goto out;
}
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (key.type != BTRFS_DEV_EXTENT_KEY)
goto next;
if (key.offset > search_start) {
hole_size = key.offset - search_start;
dev_extent_hole_check(device, &search_start, &hole_size,
num_bytes);
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
/*
* If this free space is greater than which we need,
* it must be the max free space that we have found
* until now, so max_hole_start must point to the start
* of this free space and the length of this free space
* is stored in max_hole_size. Thus, we return
* max_hole_start and max_hole_size and go back to the
* caller.
*/
if (hole_size >= num_bytes) {
ret = 0;
goto out;
}
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (extent_end > search_start)
search_start = extent_end;
next:
path->slots[0]++;
cond_resched();
}
/*
* At this point, search_start should be the end of
* allocated dev extents, and when shrinking the device,
* search_end may be smaller than search_start.
*/
if (search_end > search_start) {
hole_size = search_end - search_start;
if (dev_extent_hole_check(device, &search_start, &hole_size,
num_bytes)) {
btrfs_release_path(path);
goto again;
}
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
}
/* See above. */
if (max_hole_size < num_bytes)
ret = -ENOSPC;
else
ret = 0;
out:
btrfs_free_path(path);
*start = max_hole_start;
if (len)
*len = max_hole_size;
return ret;
}
int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
u64 *start, u64 *len)
{
/* FIXME use last free of some kind */
return find_free_dev_extent_start(device, num_bytes, 0, start, len);
}
static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 start, u64 *dev_extent_len)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf = NULL;
struct btrfs_dev_extent *extent = NULL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
again:
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid,
BTRFS_DEV_EXTENT_KEY);
if (ret)
goto out;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
BUG_ON(found_key.offset > start || found_key.offset +
btrfs_dev_extent_length(leaf, extent) < start);
key = found_key;
btrfs_release_path(path);
goto again;
} else if (ret == 0) {
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
} else {
btrfs_handle_fs_error(fs_info, ret, "Slot search failed");
goto out;
}
*dev_extent_len = btrfs_dev_extent_length(leaf, extent);
ret = btrfs_del_item(trans, root, path);
if (ret) {
btrfs_handle_fs_error(fs_info, ret,
"Failed to remove dev extent item");
} else {
set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags);
}
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 chunk_offset, u64 start, u64 num_bytes)
{
int ret;
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_dev_extent *extent;
struct extent_buffer *leaf;
struct btrfs_key key;
WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*extent));
if (ret)
goto out;
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
btrfs_set_dev_extent_chunk_tree(leaf, extent,
BTRFS_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_objectid(leaf, extent,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
btrfs_set_dev_extent_length(leaf, extent, num_bytes);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
struct rb_node *n;
u64 ret = 0;
em_tree = &fs_info->mapping_tree;
read_lock(&em_tree->lock);
n = rb_last(&em_tree->map.rb_root);
if (n) {
em = rb_entry(n, struct extent_map, rb_node);
ret = em->start + em->len;
}
read_unlock(&em_tree->lock);
return ret;
}
static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
u64 *devid_ret)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
if (ret < 0)
goto error;
if (ret == 0) {
/* Corruption */
btrfs_err(fs_info, "corrupted chunk tree devid -1 matched");
ret = -EUCLEAN;
goto error;
}
ret = btrfs_previous_item(fs_info->chunk_root, path,
BTRFS_DEV_ITEMS_OBJECTID,
BTRFS_DEV_ITEM_KEY);
if (ret) {
*devid_ret = 1;
} else {
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
*devid_ret = found_key.offset + 1;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
/*
* the device information is stored in the chunk root
* the btrfs_device struct should be fully filled in
*/
static int btrfs_add_dev_item(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
unsigned long ptr;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_insert_empty_item(trans, trans->fs_info->chunk_root, path,
&key, sizeof(*dev_item));
if (ret)
goto out;
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_generation(leaf, dev_item, 0);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item,
btrfs_device_get_disk_total_bytes(device));
btrfs_set_device_bytes_used(leaf, dev_item,
btrfs_device_get_bytes_used(device));
btrfs_set_device_group(leaf, dev_item, 0);
btrfs_set_device_seek_speed(leaf, dev_item, 0);
btrfs_set_device_bandwidth(leaf, dev_item, 0);
btrfs_set_device_start_offset(leaf, dev_item, 0);
ptr = btrfs_device_uuid(dev_item);
write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
ptr = btrfs_device_fsid(dev_item);
write_extent_buffer(leaf, trans->fs_info->fs_devices->metadata_uuid,
ptr, BTRFS_FSID_SIZE);
btrfs_mark_buffer_dirty(leaf);
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* Function to update ctime/mtime for a given device path.
* Mainly used for ctime/mtime based probe like libblkid.
*/
static void update_dev_time(const char *path_name)
{
struct file *filp;
filp = filp_open(path_name, O_RDWR, 0);
if (IS_ERR(filp))
return;
file_update_time(filp);
filp_close(filp, NULL);
}
static int btrfs_rm_dev_item(struct btrfs_device *device)
{
struct btrfs_root *root = device->fs_info->chunk_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_trans_handle *trans;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
}
out:
btrfs_free_path(path);
if (!ret)
ret = btrfs_commit_transaction(trans);
return ret;
}
/*
* Verify that @num_devices satisfies the RAID profile constraints in the whole
* filesystem. It's up to the caller to adjust that number regarding eg. device
* replace.
*/
static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
u64 num_devices)
{
u64 all_avail;
unsigned seq;
int i;
do {
seq = read_seqbegin(&fs_info->profiles_lock);
all_avail = fs_info->avail_data_alloc_bits |
fs_info->avail_system_alloc_bits |
fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&fs_info->profiles_lock, seq));
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
if (!(all_avail & btrfs_raid_array[i].bg_flag))
continue;
if (num_devices < btrfs_raid_array[i].devs_min) {
int ret = btrfs_raid_array[i].mindev_error;
if (ret)
return ret;
}
}
return 0;
}
static struct btrfs_device * btrfs_find_next_active_device(
struct btrfs_fs_devices *fs_devs, struct btrfs_device *device)
{
struct btrfs_device *next_device;
list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
if (next_device != device &&
!test_bit(BTRFS_DEV_STATE_MISSING, &next_device->dev_state)
&& next_device->bdev)
return next_device;
}
return NULL;
}
/*
* Helper function to check if the given device is part of s_bdev / latest_bdev
* and replace it with the provided or the next active device, in the context
* where this function called, there should be always be another device (or
* this_dev) which is active.
*/
void __cold btrfs_assign_next_active_device(struct btrfs_device *device,
struct btrfs_device *this_dev)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_device *next_device;
if (this_dev)
next_device = this_dev;
else
next_device = btrfs_find_next_active_device(fs_info->fs_devices,
device);
ASSERT(next_device);
if (fs_info->sb->s_bdev &&
(fs_info->sb->s_bdev == device->bdev))
fs_info->sb->s_bdev = next_device->bdev;
if (fs_info->fs_devices->latest_bdev == device->bdev)
fs_info->fs_devices->latest_bdev = next_device->bdev;
}
/*
* Return btrfs_fs_devices::num_devices excluding the device that's being
* currently replaced.
*/
static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info)
{
u64 num_devices = fs_info->fs_devices->num_devices;
down_read(&fs_info->dev_replace.rwsem);
if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
ASSERT(num_devices > 1);
num_devices--;
}
up_read(&fs_info->dev_replace.rwsem);
return num_devices;
}
static void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
struct block_device *bdev,
const char *device_path)
{
struct btrfs_super_block *disk_super;
int copy_num;
if (!bdev)
return;
for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX; copy_num++) {
struct page *page;
int ret;
disk_super = btrfs_read_dev_one_super(bdev, copy_num);
if (IS_ERR(disk_super))
continue;
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
page = virt_to_page(disk_super);
set_page_dirty(page);
lock_page(page);
/* write_on_page() unlocks the page */
ret = write_one_page(page);
if (ret)
btrfs_warn(fs_info,
"error clearing superblock number %d (%d)",
copy_num, ret);
btrfs_release_disk_super(disk_super);
}
/* Notify udev that device has changed */
btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
/* Update ctime/mtime for device path for libblkid */
update_dev_time(device_path);
}
int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
u64 devid)
{
struct btrfs_device *device;
struct btrfs_fs_devices *cur_devices;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 num_devices;
int ret = 0;
mutex_lock(&uuid_mutex);
num_devices = btrfs_num_devices(fs_info);
ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);
if (ret)
goto out;
device = btrfs_find_device_by_devspec(fs_info, devid, device_path);
if (IS_ERR(device)) {
if (PTR_ERR(device) == -ENOENT &&
strcmp(device_path, "missing") == 0)
ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
else
ret = PTR_ERR(device);
goto out;
}
if (btrfs_pinned_by_swapfile(fs_info, device)) {
btrfs_warn_in_rcu(fs_info,
"cannot remove device %s (devid %llu) due to active swapfile",
rcu_str_deref(device->name), device->devid);
ret = -ETXTBSY;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = BTRFS_ERROR_DEV_TGT_REPLACE;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
fs_info->fs_devices->rw_devices == 1) {
ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
mutex_lock(&fs_info->chunk_mutex);
list_del_init(&device->dev_alloc_list);
device->fs_devices->rw_devices--;
mutex_unlock(&fs_info->chunk_mutex);
}
mutex_unlock(&uuid_mutex);
ret = btrfs_shrink_device(device, 0);
mutex_lock(&uuid_mutex);
if (ret)
goto error_undo;
/*
* TODO: the superblock still includes this device in its num_devices
* counter although write_all_supers() is not locked out. This
* could give a filesystem state which requires a degraded mount.
*/
ret = btrfs_rm_dev_item(device);
if (ret)
goto error_undo;
clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
btrfs_scrub_cancel_dev(device);
/*
* the device list mutex makes sure that we don't change
* the device list while someone else is writing out all
* the device supers. Whoever is writing all supers, should
* lock the device list mutex before getting the number of
* devices in the super block (super_copy). Conversely,
* whoever updates the number of devices in the super block
* (super_copy) should hold the device list mutex.
*/
/*
* In normal cases the cur_devices == fs_devices. But in case
* of deleting a seed device, the cur_devices should point to
* its own fs_devices listed under the fs_devices->seed.
*/
cur_devices = device->fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
list_del_rcu(&device->dev_list);
cur_devices->num_devices--;
cur_devices->total_devices--;
/* Update total_devices of the parent fs_devices if it's seed */
if (cur_devices != fs_devices)
fs_devices->total_devices--;
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
cur_devices->missing_devices--;
btrfs_assign_next_active_device(device, NULL);
if (device->bdev) {
cur_devices->open_devices--;
/* remove sysfs entry */
btrfs_sysfs_remove_devices_dir(fs_devices, device);
}
num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1;
btrfs_set_super_num_devices(fs_info->super_copy, num_devices);
mutex_unlock(&fs_devices->device_list_mutex);
/*
* at this point, the device is zero sized and detached from
* the devices list. All that's left is to zero out the old
* supers and free the device.
*/
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
btrfs_scratch_superblocks(fs_info, device->bdev,
device->name->str);
btrfs_close_bdev(device);
synchronize_rcu();
btrfs_free_device(device);
if (cur_devices->open_devices == 0) {
while (fs_devices) {
if (fs_devices->seed == cur_devices) {
fs_devices->seed = cur_devices->seed;
break;
}
fs_devices = fs_devices->seed;
}
cur_devices->seed = NULL;
close_fs_devices(cur_devices);
free_fs_devices(cur_devices);
}
out:
mutex_unlock(&uuid_mutex);
return ret;
error_undo:
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
mutex_lock(&fs_info->chunk_mutex);
list_add(&device->dev_alloc_list,
&fs_devices->alloc_list);
device->fs_devices->rw_devices++;
mutex_unlock(&fs_info->chunk_mutex);
}
goto out;
}
void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev)
{
struct btrfs_fs_devices *fs_devices;
lockdep_assert_held(&srcdev->fs_info->fs_devices->device_list_mutex);
/*
* in case of fs with no seed, srcdev->fs_devices will point
* to fs_devices of fs_info. However when the dev being replaced is
* a seed dev it will point to the seed's local fs_devices. In short
* srcdev will have its correct fs_devices in both the cases.
*/
fs_devices = srcdev->fs_devices;
list_del_rcu(&srcdev->dev_list);
list_del(&srcdev->dev_alloc_list);
fs_devices->num_devices--;
if (test_bit(BTRFS_DEV_STATE_MISSING, &srcdev->dev_state))
fs_devices->missing_devices--;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state))
fs_devices->rw_devices--;
if (srcdev->bdev)
fs_devices->open_devices--;
}
void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev)
{
struct btrfs_fs_info *fs_info = srcdev->fs_info;
struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) {
/* zero out the old super if it is writable */
btrfs_scratch_superblocks(fs_info, srcdev->bdev,
srcdev->name->str);
}
btrfs_close_bdev(srcdev);
synchronize_rcu();
btrfs_free_device(srcdev);
/* if this is no devs we rather delete the fs_devices */
if (!fs_devices->num_devices) {
struct btrfs_fs_devices *tmp_fs_devices;
/*
* On a mounted FS, num_devices can't be zero unless it's a
* seed. In case of a seed device being replaced, the replace
* target added to the sprout FS, so there will be no more
* device left under the seed FS.
*/
ASSERT(fs_devices->seeding);
tmp_fs_devices = fs_info->fs_devices;
while (tmp_fs_devices) {
if (tmp_fs_devices->seed == fs_devices) {
tmp_fs_devices->seed = fs_devices->seed;
break;
}
tmp_fs_devices = tmp_fs_devices->seed;
}
fs_devices->seed = NULL;
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
}
void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
{
struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
btrfs_sysfs_remove_devices_dir(fs_devices, tgtdev);
if (tgtdev->bdev)
fs_devices->open_devices--;
fs_devices->num_devices--;
btrfs_assign_next_active_device(tgtdev, NULL);
list_del_rcu(&tgtdev->dev_list);
mutex_unlock(&fs_devices->device_list_mutex);
/*
* The update_dev_time() with in btrfs_scratch_superblocks()
* may lead to a call to btrfs_show_devname() which will try
* to hold device_list_mutex. And here this device
* is already out of device list, so we don't have to hold
* the device_list_mutex lock.
*/
btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev->bdev,
tgtdev->name->str);
btrfs_close_bdev(tgtdev);
synchronize_rcu();
btrfs_free_device(tgtdev);
}
static struct btrfs_device *btrfs_find_device_by_path(
struct btrfs_fs_info *fs_info, const char *device_path)
{
int ret = 0;
struct btrfs_super_block *disk_super;
u64 devid;
u8 *dev_uuid;
struct block_device *bdev;
struct btrfs_device *device;
ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
fs_info->bdev_holder, 0, &bdev, &disk_super);
if (ret)
return ERR_PTR(ret);
devid = btrfs_stack_device_id(&disk_super->dev_item);
dev_uuid = disk_super->dev_item.uuid;
if (btrfs_fs_incompat(fs_info, METADATA_UUID))
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
disk_super->metadata_uuid, true);
else
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
disk_super->fsid, true);
btrfs_release_disk_super(disk_super);
if (!device)
device = ERR_PTR(-ENOENT);
blkdev_put(bdev, FMODE_READ);
return device;
}
/*
* Lookup a device given by device id, or the path if the id is 0.
*/
struct btrfs_device *btrfs_find_device_by_devspec(
struct btrfs_fs_info *fs_info, u64 devid,
const char *device_path)
{
struct btrfs_device *device;
if (devid) {
device = btrfs_find_device(fs_info->fs_devices, devid, NULL,
NULL, true);
if (!device)
return ERR_PTR(-ENOENT);
return device;
}
if (!device_path || !device_path[0])
return ERR_PTR(-EINVAL);
if (strcmp(device_path, "missing") == 0) {
/* Find first missing device */
list_for_each_entry(device, &fs_info->fs_devices->devices,
dev_list) {
if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) && !device->bdev)
return device;
}
return ERR_PTR(-ENOENT);
}
return btrfs_find_device_by_path(fs_info, device_path);
}
/*
* does all the dirty work required for changing file system's UUID.
*/
static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_fs_devices *old_devices;
struct btrfs_fs_devices *seed_devices;
struct btrfs_super_block *disk_super = fs_info->super_copy;
struct btrfs_device *device;
u64 super_flags;
lockdep_assert_held(&uuid_mutex);
if (!fs_devices->seeding)
return -EINVAL;
seed_devices = alloc_fs_devices(NULL, NULL);
if (IS_ERR(seed_devices))
return PTR_ERR(seed_devices);
old_devices = clone_fs_devices(fs_devices);
if (IS_ERR(old_devices)) {
kfree(seed_devices);
return PTR_ERR(old_devices);
}
list_add(&old_devices->fs_list, &fs_uuids);
memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
seed_devices->opened = 1;
INIT_LIST_HEAD(&seed_devices->devices);
INIT_LIST_HEAD(&seed_devices->alloc_list);
mutex_init(&seed_devices->device_list_mutex);
mutex_lock(&fs_devices->device_list_mutex);
list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
synchronize_rcu);
list_for_each_entry(device, &seed_devices->devices, dev_list)
device->fs_devices = seed_devices;
mutex_lock(&fs_info->chunk_mutex);
list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
mutex_unlock(&fs_info->chunk_mutex);
fs_devices->seeding = false;
fs_devices->num_devices = 0;
fs_devices->open_devices = 0;
fs_devices->missing_devices = 0;
fs_devices->rotating = false;
fs_devices->seed = seed_devices;
generate_random_uuid(fs_devices->fsid);
memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE);
memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
mutex_unlock(&fs_devices->device_list_mutex);
super_flags = btrfs_super_flags(disk_super) &
~BTRFS_SUPER_FLAG_SEEDING;
btrfs_set_super_flags(disk_super, super_flags);
return 0;
}
/*
* Store the expected generation for seed devices in device items.
*/
static int btrfs_finish_sprout(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dev_item *dev_item;
struct btrfs_device *device;
struct btrfs_key key;
u8 fs_uuid[BTRFS_FSID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
u64 devid;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = BTRFS_DEV_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto error;
leaf = path->nodes[0];
next_slot:
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret > 0)
break;
if (ret < 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
continue;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
key.type != BTRFS_DEV_ITEM_KEY)
break;
dev_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_item);
devid = btrfs_device_id(leaf, dev_item);
read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
BTRFS_FSID_SIZE);
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
fs_uuid, true);
BUG_ON(!device); /* Logic error */
if (device->fs_devices->seeding) {
btrfs_set_device_generation(leaf, dev_item,
device->generation);
btrfs_mark_buffer_dirty(leaf);
}
path->slots[0]++;
goto next_slot;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path)
{
struct btrfs_root *root = fs_info->dev_root;
struct request_queue *q;
struct btrfs_trans_handle *trans;
struct btrfs_device *device;
struct block_device *bdev;
struct super_block *sb = fs_info->sb;
struct rcu_string *name;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 orig_super_total_bytes;
u64 orig_super_num_devices;
int seeding_dev = 0;
int ret = 0;
bool unlocked = false;
if (sb_rdonly(sb) && !fs_devices->seeding)
return -EROFS;
bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
fs_info->bdev_holder);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
if (fs_devices->seeding) {
seeding_dev = 1;
down_write(&sb->s_umount);
mutex_lock(&uuid_mutex);
}
filemap_write_and_wait(bdev->bd_inode->i_mapping);
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
if (device->bdev == bdev) {
ret = -EEXIST;
mutex_unlock(
&fs_devices->device_list_mutex);
goto error;
}
}
mutex_unlock(&fs_devices->device_list_mutex);
device = btrfs_alloc_device(fs_info, NULL, NULL);
if (IS_ERR(device)) {
/* we can safely leave the fs_devices entry around */
ret = PTR_ERR(device);
goto error;
}
name = rcu_string_strdup(device_path, GFP_KERNEL);
if (!name) {
ret = -ENOMEM;
goto error_free_device;
}
rcu_assign_pointer(device->name, name);
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error_free_device;
}
q = bdev_get_queue(bdev);
set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
device->generation = trans->transid;
device->io_width = fs_info->sectorsize;
device->io_align = fs_info->sectorsize;
device->sector_size = fs_info->sectorsize;
device->total_bytes = round_down(i_size_read(bdev->bd_inode),
fs_info->sectorsize);
device->disk_total_bytes = device->total_bytes;
device->commit_total_bytes = device->total_bytes;
device->fs_info = fs_info;
device->bdev = bdev;
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
device->mode = FMODE_EXCL;
device->dev_stats_valid = 1;
set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
if (seeding_dev) {
sb->s_flags &= ~SB_RDONLY;
ret = btrfs_prepare_sprout(fs_info);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_trans;
}
}
device->fs_devices = fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
mutex_lock(&fs_info->chunk_mutex);
list_add_rcu(&device->dev_list, &fs_devices->devices);
list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
fs_devices->num_devices++;
fs_devices->open_devices++;
fs_devices->rw_devices++;
fs_devices->total_devices++;
fs_devices->total_rw_bytes += device->total_bytes;
atomic64_add(device->total_bytes, &fs_info->free_chunk_space);
if (!blk_queue_nonrot(q))
fs_devices->rotating = true;
orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
btrfs_set_super_total_bytes(fs_info->super_copy,
round_down(orig_super_total_bytes + device->total_bytes,
fs_info->sectorsize));
orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy);
btrfs_set_super_num_devices(fs_info->super_copy,
orig_super_num_devices + 1);
/* add sysfs device entry */
btrfs_sysfs_add_devices_dir(fs_devices, device);
/*
* we've got more storage, clear any full flags on the space
* infos
*/
btrfs_clear_space_info_full(fs_info);
mutex_unlock(&fs_info->chunk_mutex);
mutex_unlock(&fs_devices->device_list_mutex);
if (seeding_dev) {
mutex_lock(&fs_info->chunk_mutex);
ret = init_first_rw_device(trans);
mutex_unlock(&fs_info->chunk_mutex);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
}
ret = btrfs_add_dev_item(trans, device);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
if (seeding_dev) {
ret = btrfs_finish_sprout(trans);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
btrfs_sysfs_update_sprout_fsid(fs_devices,
fs_info->fs_devices->fsid);
}
ret = btrfs_commit_transaction(trans);
if (seeding_dev) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
unlocked = true;
if (ret) /* transaction commit */
return ret;
ret = btrfs_relocate_sys_chunks(fs_info);
if (ret < 0)
btrfs_handle_fs_error(fs_info, ret,
"Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command.");
trans = btrfs_attach_transaction(root);
if (IS_ERR(trans)) {
if (PTR_ERR(trans) == -ENOENT)
return 0;
ret = PTR_ERR(trans);
trans = NULL;
goto error_sysfs;
}
ret = btrfs_commit_transaction(trans);
}
/*
* Now that we have written a new super block to this device, check all
* other fs_devices list if device_path alienates any other scanned
* device.
* We can ignore the return value as it typically returns -EINVAL and
* only succeeds if the device was an alien.
*/
btrfs_forget_devices(device_path);
/* Update ctime/mtime for blkid or udev */
update_dev_time(device_path);
return ret;
error_sysfs:
btrfs_sysfs_remove_devices_dir(fs_devices, device);
mutex_lock(&fs_info->fs_devices->device_list_mutex);
mutex_lock(&fs_info->chunk_mutex);
list_del_rcu(&device->dev_list);
list_del(&device->dev_alloc_list);
fs_info->fs_devices->num_devices--;
fs_info->fs_devices->open_devices--;
fs_info->fs_devices->rw_devices--;
fs_info->fs_devices->total_devices--;
fs_info->fs_devices->total_rw_bytes -= device->total_bytes;
atomic64_sub(device->total_bytes, &fs_info->free_chunk_space);
btrfs_set_super_total_bytes(fs_info->super_copy,
orig_super_total_bytes);
btrfs_set_super_num_devices(fs_info->super_copy,
orig_super_num_devices);
mutex_unlock(&fs_info->chunk_mutex);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
error_trans:
if (seeding_dev)
sb->s_flags |= SB_RDONLY;
if (trans)
btrfs_end_transaction(trans);
error_free_device:
btrfs_free_device(device);
error:
blkdev_put(bdev, FMODE_EXCL);
if (seeding_dev && !unlocked) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
}
return ret;
}
static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_root *root = device->fs_info->chunk_root;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item,
btrfs_device_get_disk_total_bytes(device));
btrfs_set_device_bytes_used(leaf, dev_item,
btrfs_device_get_bytes_used(device));
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_grow_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 new_size)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_super_block *super_copy = fs_info->super_copy;
u64 old_total;
u64 diff;
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
return -EACCES;
new_size = round_down(new_size, fs_info->sectorsize);
mutex_lock(&fs_info->chunk_mutex);
old_total = btrfs_super_total_bytes(super_copy);
diff = round_down(new_size - device->total_bytes, fs_info->sectorsize);
if (new_size <= device->total_bytes ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
mutex_unlock(&fs_info->chunk_mutex);
return -EINVAL;
}
btrfs_set_super_total_bytes(super_copy,
round_down(old_total + diff, fs_info->sectorsize));
device->fs_devices->total_rw_bytes += diff;
btrfs_device_set_total_bytes(device, new_size);
btrfs_device_set_disk_total_bytes(device, new_size);
btrfs_clear_space_info_full(device->fs_info);
if (list_empty(&device->post_commit_list))
list_add_tail(&device->post_commit_list,
&trans->transaction->dev_update_list);
mutex_unlock(&fs_info->chunk_mutex);
return btrfs_update_device(trans, device);
}
static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root = fs_info->chunk_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = chunk_offset;
key.type = BTRFS_CHUNK_ITEM_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
else if (ret > 0) { /* Logic error or corruption */
btrfs_handle_fs_error(fs_info, -ENOENT,
"Failed lookup while freeing chunk.");
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret < 0)
btrfs_handle_fs_error(fs_info, ret,
"Failed to delete chunk item.");
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *ptr;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur;
struct btrfs_key key;
mutex_lock(&fs_info->chunk_mutex);
array_size = btrfs_super_sys_array_size(super_copy);
ptr = super_copy->sys_chunk_array;
cur = 0;
while (cur < array_size) {
disk_key = (struct btrfs_disk_key *)ptr;
btrfs_disk_key_to_cpu(&key, disk_key);
len = sizeof(*disk_key);
if (key.type == BTRFS_CHUNK_ITEM_KEY) {
chunk = (struct btrfs_chunk *)(ptr + len);
num_stripes = btrfs_stack_chunk_num_stripes(chunk);
len += btrfs_chunk_item_size(num_stripes);
} else {
ret = -EIO;
break;
}
if (key.objectid == BTRFS_FIRST_CHUNK_TREE_OBJECTID &&
key.offset == chunk_offset) {
memmove(ptr, ptr + len, array_size - (cur + len));
array_size -= len;
btrfs_set_super_sys_array_size(super_copy, array_size);
} else {
ptr += len;
cur += len;
}
}
mutex_unlock(&fs_info->chunk_mutex);
return ret;
}
/*
* btrfs_get_chunk_map() - Find the mapping containing the given logical extent.
* @logical: Logical block offset in bytes.
* @length: Length of extent in bytes.
*
* Return: Chunk mapping or ERR_PTR.
*/
struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
u64 logical, u64 length)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
em_tree = &fs_info->mapping_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, length);
read_unlock(&em_tree->lock);
if (!em) {
btrfs_crit(fs_info, "unable to find logical %llu length %llu",
logical, length);
return ERR_PTR(-EINVAL);
}
if (em->start > logical || em->start + em->len < logical) {
btrfs_crit(fs_info,
"found a bad mapping, wanted %llu-%llu, found %llu-%llu",
logical, length, em->start, em->start + em->len);
free_extent_map(em);
return ERR_PTR(-EINVAL);
}
/* callers are responsible for dropping em's ref. */
return em;
}
int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct extent_map *em;
struct map_lookup *map;
u64 dev_extent_len = 0;
int i, ret = 0;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
if (IS_ERR(em)) {
/*
* This is a logic error, but we don't want to just rely on the
* user having built with ASSERT enabled, so if ASSERT doesn't
* do anything we still error out.
*/
ASSERT(0);
return PTR_ERR(em);
}
map = em->map_lookup;
mutex_lock(&fs_info->chunk_mutex);
check_system_chunk(trans, map->type);
mutex_unlock(&fs_info->chunk_mutex);
/*
* Take the device list mutex to prevent races with the final phase of
* a device replace operation that replaces the device object associated
* with map stripes (dev-replace.c:btrfs_dev_replace_finishing()).
*/
mutex_lock(&fs_devices->device_list_mutex);
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *device = map->stripes[i].dev;
ret = btrfs_free_dev_extent(trans, device,
map->stripes[i].physical,
&dev_extent_len);
if (ret) {
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_abort_transaction(trans, ret);
goto out;
}
if (device->bytes_used > 0) {
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_bytes_used(device,
device->bytes_used - dev_extent_len);
atomic64_add(dev_extent_len, &fs_info->free_chunk_space);
btrfs_clear_space_info_full(fs_info);
mutex_unlock(&fs_info->chunk_mutex);
}
ret = btrfs_update_device(trans, device);
if (ret) {
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_abort_transaction(trans, ret);
goto out;
}
}
mutex_unlock(&fs_devices->device_list_mutex);
ret = btrfs_free_chunk(trans, chunk_offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
trace_btrfs_chunk_free(fs_info, map, chunk_offset, em->len);
if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_del_sys_chunk(fs_info, chunk_offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
}
ret = btrfs_remove_block_group(trans, chunk_offset, em);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
out:
/* once for us */
free_extent_map(em);
return ret;
}
static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_trans_handle *trans;
struct btrfs_block_group *block_group;
int ret;
/*
* Prevent races with automatic removal of unused block groups.
* After we relocate and before we remove the chunk with offset
* chunk_offset, automatic removal of the block group can kick in,
* resulting in a failure when calling btrfs_remove_chunk() below.
*
* Make sure to acquire this mutex before doing a tree search (dev
* or chunk trees) to find chunks. Otherwise the cleaner kthread might
* call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after
* we release the path used to search the chunk/dev tree and before
* the current task acquires this mutex and calls us.
*/
lockdep_assert_held(&fs_info->delete_unused_bgs_mutex);
/* step one, relocate all the extents inside this chunk */
btrfs_scrub_pause(fs_info);
ret = btrfs_relocate_block_group(fs_info, chunk_offset);
btrfs_scrub_continue(fs_info);
if (ret)
return ret;
block_group = btrfs_lookup_block_group(fs_info, chunk_offset);
if (!block_group)
return -ENOENT;
btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group);
btrfs_put_block_group(block_group);
trans = btrfs_start_trans_remove_block_group(root->fs_info,
chunk_offset);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_handle_fs_error(root->fs_info, ret, NULL);
return ret;
}
/*
* step two, delete the device extents and the
* chunk tree entries
*/
ret = btrfs_remove_chunk(trans, chunk_offset);
btrfs_end_transaction(trans);
return ret;
}
static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_chunk *chunk;
struct btrfs_key key;
struct btrfs_key found_key;
u64 chunk_type;
bool retried = false;
int failed = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
}
BUG_ON(ret == 0); /* Corruption */
ret = btrfs_previous_item(chunk_root, path, key.objectid,
key.type);
if (ret)
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret < 0)
goto error;
if (ret > 0)
break;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
chunk = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_chunk);
chunk_type = btrfs_chunk_type(leaf, chunk);
btrfs_release_path(path);
if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_relocate_chunk(fs_info, found_key.offset);
if (ret == -ENOSPC)
failed++;
else
BUG_ON(ret);
}
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
ret = 0;
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (WARN_ON(failed && retried)) {
ret = -ENOSPC;
}
error:
btrfs_free_path(path);
return ret;
}
/*
* return 1 : allocate a data chunk successfully,
* return <0: errors during allocating a data chunk,
* return 0 : no need to allocate a data chunk.
*/
static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info,
u64 chunk_offset)
{
struct btrfs_block_group *cache;
u64 bytes_used;
u64 chunk_type;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
ASSERT(cache);
chunk_type = cache->flags;
btrfs_put_block_group(cache);
if (!(chunk_type & BTRFS_BLOCK_GROUP_DATA))
return 0;
spin_lock(&fs_info->data_sinfo->lock);
bytes_used = fs_info->data_sinfo->bytes_used;
spin_unlock(&fs_info->data_sinfo->lock);
if (!bytes_used) {
struct btrfs_trans_handle *trans;
int ret;
trans = btrfs_join_transaction(fs_info->tree_root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_force_chunk_alloc(trans, BTRFS_BLOCK_GROUP_DATA);
btrfs_end_transaction(trans);
if (ret < 0)
return ret;
return 1;
}
return 0;
}
static int insert_balance_item(struct btrfs_fs_info *fs_info,
struct btrfs_balance_control *bctl)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_trans_handle *trans;
struct btrfs_balance_item *item;
struct btrfs_disk_balance_args disk_bargs;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret, err;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*item));
if (ret)
goto out;
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
btrfs_set_balance_data(leaf, item, &disk_bargs);
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
btrfs_set_balance_meta(leaf, item, &disk_bargs);
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
btrfs_set_balance_sys(leaf, item, &disk_bargs);
btrfs_set_balance_flags(leaf, item, bctl->flags);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
err = btrfs_commit_transaction(trans);
if (err && !ret)
ret = err;
return ret;
}
static int del_balance_item(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct btrfs_key key;
int ret, err;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction_fallback_global_rsv(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
err = btrfs_commit_transaction(trans);
if (err && !ret)
ret = err;
return ret;
}
/*
* This is a heuristic used to reduce the number of chunks balanced on
* resume after balance was interrupted.
*/
static void update_balance_args(struct btrfs_balance_control *bctl)
{
/*
* Turn on soft mode for chunk types that were being converted.
*/
if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
/*
* Turn on usage filter if is not already used. The idea is
* that chunks that we have already balanced should be
* reasonably full. Don't do it for chunks that are being
* converted - that will keep us from relocating unconverted
* (albeit full) chunks.
*/
if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->data.usage = 90;
}
if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->sys.usage = 90;
}
if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->meta.usage = 90;
}
}
/*
* Clear the balance status in fs_info and delete the balance item from disk.
*/
static void reset_balance_state(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
int ret;
BUG_ON(!fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = NULL;
spin_unlock(&fs_info->balance_lock);
kfree(bctl);
ret = del_balance_item(fs_info);
if (ret)
btrfs_handle_fs_error(fs_info, ret, NULL);
}
/*
* Balance filters. Return 1 if chunk should be filtered out
* (should not be balanced).
*/
static int chunk_profiles_filter(u64 chunk_type,
struct btrfs_balance_args *bargs)
{
chunk_type = chunk_to_extended(chunk_type) &
BTRFS_EXTENDED_PROFILE_MASK;
if (bargs->profiles & chunk_type)
return 0;
return 1;
}
static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
struct btrfs_block_group *cache;
u64 chunk_used;
u64 user_thresh_min;
u64 user_thresh_max;
int ret = 1;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used;
if (bargs->usage_min == 0)
user_thresh_min = 0;
else
user_thresh_min = div_factor_fine(cache->length,
bargs->usage_min);
if (bargs->usage_max == 0)
user_thresh_max = 1;
else if (bargs->usage_max > 100)
user_thresh_max = cache->length;
else
user_thresh_max = div_factor_fine(cache->length,
bargs->usage_max);
if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max)
ret = 0;
btrfs_put_block_group(cache);
return ret;
}
static int chunk_usage_filter(struct btrfs_fs_info *fs_info,
u64 chunk_offset, struct btrfs_balance_args *bargs)
{
struct btrfs_block_group *cache;
u64 chunk_used, user_thresh;
int ret = 1;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used;
if (bargs->usage_min == 0)
user_thresh = 1;
else if (bargs->usage > 100)
user_thresh = cache->length;
else
user_thresh = div_factor_fine(cache->length, bargs->usage);
if (chunk_used < user_thresh)
ret = 0;
btrfs_put_block_group(cache);
return ret;
}
static int chunk_devid_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
int i;
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
return 0;
}
return 1;
}
static u64 calc_data_stripes(u64 type, int num_stripes)
{
const int index = btrfs_bg_flags_to_raid_index(type);
const int ncopies = btrfs_raid_array[index].ncopies;
const int nparity = btrfs_raid_array[index].nparity;
if (nparity)
return num_stripes - nparity;
else
return num_stripes / ncopies;
}
/* [pstart, pend) */
static int chunk_drange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
u64 stripe_offset;
u64 stripe_length;
u64 type;
int factor;
int i;
if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
return 0;
type = btrfs_chunk_type(leaf, chunk);
factor = calc_data_stripes(type, num_stripes);
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
continue;
stripe_offset = btrfs_stripe_offset(leaf, stripe);
stripe_length = btrfs_chunk_length(leaf, chunk);
stripe_length = div_u64(stripe_length, factor);
if (stripe_offset < bargs->pend &&
stripe_offset + stripe_length > bargs->pstart)
return 0;
}
return 1;
}
/* [vstart, vend) */
static int chunk_vrange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
if (chunk_offset < bargs->vend &&
chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
/* at least part of the chunk is inside this vrange */
return 0;
return 1;
}
static int chunk_stripes_range_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
if (bargs->stripes_min <= num_stripes
&& num_stripes <= bargs->stripes_max)
return 0;
return 1;
}
static int chunk_soft_convert_filter(u64 chunk_type,
struct btrfs_balance_args *bargs)
{
if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
return 0;
chunk_type = chunk_to_extended(chunk_type) &
BTRFS_EXTENDED_PROFILE_MASK;
if (bargs->target == chunk_type)
return 1;
return 0;
}
static int should_balance_chunk(struct extent_buffer *leaf,
struct btrfs_chunk *chunk, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
struct btrfs_balance_args *bargs = NULL;
u64 chunk_type = btrfs_chunk_type(leaf, chunk);
/* type filter */
if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
(bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
return 0;
}
if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
bargs = &bctl->data;
else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
bargs = &bctl->sys;
else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
bargs = &bctl->meta;
/* profiles filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
chunk_profiles_filter(chunk_type, bargs)) {
return 0;
}
/* usage filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
chunk_usage_filter(fs_info, chunk_offset, bargs)) {
return 0;
} else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
chunk_usage_range_filter(fs_info, chunk_offset, bargs)) {
return 0;
}
/* devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
chunk_devid_filter(leaf, chunk, bargs)) {
return 0;
}
/* drange filter, makes sense only with devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
chunk_drange_filter(leaf, chunk, bargs)) {
return 0;
}
/* vrange filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
return 0;
}
/* stripes filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) &&
chunk_stripes_range_filter(leaf, chunk, bargs)) {
return 0;
}
/* soft profile changing mode */
if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
chunk_soft_convert_filter(chunk_type, bargs)) {
return 0;
}
/*
* limited by count, must be the last filter
*/
if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
if (bargs->limit == 0)
return 0;
else
bargs->limit--;
} else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) {
/*
* Same logic as the 'limit' filter; the minimum cannot be
* determined here because we do not have the global information
* about the count of all chunks that satisfy the filters.
*/
if (bargs->limit_max == 0)
return 0;
else
bargs->limit_max--;
}
return 1;
}
static int __btrfs_balance(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
struct btrfs_root *chunk_root = fs_info->chunk_root;
u64 chunk_type;
struct btrfs_chunk *chunk;
struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int slot;
int ret;
int enospc_errors = 0;
bool counting = true;
/* The single value limit and min/max limits use the same bytes in the */
u64 limit_data = bctl->data.limit;
u64 limit_meta = bctl->meta.limit;
u64 limit_sys = bctl->sys.limit;
u32 count_data = 0;
u32 count_meta = 0;
u32 count_sys = 0;
int chunk_reserved = 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto error;
}
/* zero out stat counters */
spin_lock(&fs_info->balance_lock);
memset(&bctl->stat, 0, sizeof(bctl->stat));
spin_unlock(&fs_info->balance_lock);
again:
if (!counting) {
/*
* The single value limit and min/max limits use the same bytes
* in the
*/
bctl->data.limit = limit_data;
bctl->meta.limit = limit_meta;
bctl->sys.limit = limit_sys;
}
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
atomic_read(&fs_info->balance_cancel_req)) {
ret = -ECANCELED;
goto error;
}
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
}
/*
* this shouldn't happen, it means the last relocate
* failed
*/
if (ret == 0)
BUG(); /* FIXME break ? */
ret = btrfs_previous_item(chunk_root, path, 0,
BTRFS_CHUNK_ITEM_KEY);
if (ret) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
ret = 0;
break;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
break;
}
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
chunk_type = btrfs_chunk_type(leaf, chunk);
if (!counting) {
spin_lock(&fs_info->balance_lock);
bctl->stat.considered++;
spin_unlock(&fs_info->balance_lock);
}
ret = should_balance_chunk(leaf, chunk, found_key.offset);
btrfs_release_path(path);
if (!ret) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto loop;
}
if (counting) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
spin_lock(&fs_info->balance_lock);
bctl->stat.expected++;
spin_unlock(&fs_info->balance_lock);
if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
count_data++;
else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
count_sys++;
else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
count_meta++;
goto loop;
}
/*
* Apply limit_min filter, no need to check if the LIMITS
* filter is used, limit_min is 0 by default
*/
if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
count_data < bctl->data.limit_min)
|| ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) &&
count_meta < bctl->meta.limit_min)
|| ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) &&
count_sys < bctl->sys.limit_min)) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto loop;
}
if (!chunk_reserved) {
/*
* We may be relocating the only data chunk we have,
* which could potentially end up with losing data's
* raid profile, so lets allocate an empty one in
* advance.
*/
ret = btrfs_may_alloc_data_chunk(fs_info,
found_key.offset);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
} else if (ret == 1) {
chunk_reserved = 1;
}
}
ret = btrfs_relocate_chunk(fs_info, found_key.offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret == -ENOSPC) {
enospc_errors++;
} else if (ret == -ETXTBSY) {
btrfs_info(fs_info,
"skipping relocation of block group %llu due to active swapfile",
found_key.offset);
ret = 0;
} else if (ret) {
goto error;
} else {
spin_lock(&fs_info->balance_lock);
bctl->stat.completed++;
spin_unlock(&fs_info->balance_lock);
}
loop:
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
if (counting) {
btrfs_release_path(path);
counting = false;
goto again;
}
error:
btrfs_free_path(path);
if (enospc_errors) {
btrfs_info(fs_info, "%d enospc errors during balance",
enospc_errors);
if (!ret)
ret = -ENOSPC;
}
return ret;
}
/**
* alloc_profile_is_valid - see if a given profile is valid and reduced
* @flags: profile to validate
* @extended: if true @flags is treated as an extended profile
*/
static int alloc_profile_is_valid(u64 flags, int extended)
{
u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
BTRFS_BLOCK_GROUP_PROFILE_MASK);
flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
/* 1) check that all other bits are zeroed */
if (flags & ~mask)
return 0;
/* 2) see if profile is reduced */
if (flags == 0)
return !extended; /* "0" is valid for usual profiles */
return has_single_bit_set(flags);
}
static inline int balance_need_close(struct btrfs_fs_info *fs_info)
{
/* cancel requested || normal exit path */
return atomic_read(&fs_info->balance_cancel_req) ||
(atomic_read(&fs_info->balance_pause_req) == 0 &&
atomic_read(&fs_info->balance_cancel_req) == 0);
}
/*
* Validate target profile against allowed profiles and return true if it's OK.
* Otherwise print the error message and return false.
*/
static inline int validate_convert_profile(struct btrfs_fs_info *fs_info,
const struct btrfs_balance_args *bargs,
u64 allowed, const char *type)
{
if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
return true;
/* Profile is valid and does not have bits outside of the allowed set */
if (alloc_profile_is_valid(bargs->target, 1) &&
(bargs->target & ~allowed) == 0)
return true;
btrfs_err(fs_info, "balance: invalid convert %s profile %s",
type, btrfs_bg_type_to_raid_name(bargs->target));
return false;
}
/*
* Fill @buf with textual description of balance filter flags @bargs, up to
* @size_buf including the terminating null. The output may be trimmed if it
* does not fit into the provided buffer.
*/
static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf,
u32 size_buf)
{
int ret;
u32 size_bp = size_buf;
char *bp = buf;
u64 flags = bargs->flags;
char tmp_buf[128] = {'\0'};
if (!flags)
return;
#define CHECK_APPEND_NOARG(a) \
do { \
ret = snprintf(bp, size_bp, (a)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
#define CHECK_APPEND_1ARG(a, v1) \
do { \
ret = snprintf(bp, size_bp, (a), (v1)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
#define CHECK_APPEND_2ARG(a, v1, v2) \
do { \
ret = snprintf(bp, size_bp, (a), (v1), (v2)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
if (flags & BTRFS_BALANCE_ARGS_CONVERT)
CHECK_APPEND_1ARG("convert=%s,",
btrfs_bg_type_to_raid_name(bargs->target));
if (flags & BTRFS_BALANCE_ARGS_SOFT)
CHECK_APPEND_NOARG("soft,");
if (flags & BTRFS_BALANCE_ARGS_PROFILES) {
btrfs_describe_block_groups(bargs->profiles, tmp_buf,
sizeof(tmp_buf));
CHECK_APPEND_1ARG("profiles=%s,", tmp_buf);
}
if (flags & BTRFS_BALANCE_ARGS_USAGE)
CHECK_APPEND_1ARG("usage=%llu,", bargs->usage);
if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE)
CHECK_APPEND_2ARG("usage=%u..%u,",
bargs->usage_min, bargs->usage_max);
if (flags & BTRFS_BALANCE_ARGS_DEVID)
CHECK_APPEND_1ARG("devid=%llu,", bargs->devid);
if (flags & BTRFS_BALANCE_ARGS_DRANGE)
CHECK_APPEND_2ARG("drange=%llu..%llu,",
bargs->pstart, bargs->pend);
if (flags & BTRFS_BALANCE_ARGS_VRANGE)
CHECK_APPEND_2ARG("vrange=%llu..%llu,",
bargs->vstart, bargs->vend);
if (flags & BTRFS_BALANCE_ARGS_LIMIT)
CHECK_APPEND_1ARG("limit=%llu,", bargs->limit);
if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)
CHECK_APPEND_2ARG("limit=%u..%u,",
bargs->limit_min, bargs->limit_max);
if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE)
CHECK_APPEND_2ARG("stripes=%u..%u,",
bargs->stripes_min, bargs->stripes_max);
#undef CHECK_APPEND_2ARG
#undef CHECK_APPEND_1ARG
#undef CHECK_APPEND_NOARG
out_overflow:
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last , */
else
buf[0] = '\0';
}
static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info)
{
u32 size_buf = 1024;
char tmp_buf[192] = {'\0'};
char *buf;
char *bp;
u32 size_bp = size_buf;
int ret;
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
buf = kzalloc(size_buf, GFP_KERNEL);
if (!buf)
return;
bp = buf;
#define CHECK_APPEND_1ARG(a, v1) \
do { \
ret = snprintf(bp, size_bp, (a), (v1)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
if (bctl->flags & BTRFS_BALANCE_FORCE)
CHECK_APPEND_1ARG("%s", "-f ");
if (bctl->flags & BTRFS_BALANCE_DATA) {
describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-d%s ", tmp_buf);
}
if (bctl->flags & BTRFS_BALANCE_METADATA) {
describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-m%s ", tmp_buf);
}
if (bctl->flags & BTRFS_BALANCE_SYSTEM) {
describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-s%s ", tmp_buf);
}
#undef CHECK_APPEND_1ARG
out_overflow:
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */
btrfs_info(fs_info, "balance: %s %s",
(bctl->flags & BTRFS_BALANCE_RESUME) ?
"resume" : "start", buf);
kfree(buf);
}
/*
* Should be called with balance mutexe held
*/
int btrfs_balance(struct btrfs_fs_info *fs_info,
struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs)
{
u64 meta_target, data_target;
u64 allowed;
int mixed = 0;
int ret;
u64 num_devices;
unsigned seq;
bool reducing_redundancy;
int i;
if (btrfs_fs_closing(fs_info) ||
atomic_read(&fs_info->balance_pause_req) ||
btrfs_should_cancel_balance(fs_info)) {
ret = -EINVAL;
goto out;
}
allowed = btrfs_super_incompat_flags(fs_info->super_copy);
if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
mixed = 1;
/*
* In case of mixed groups both data and meta should be picked,
* and identical options should be given for both of them.
*/
allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
if (mixed && (bctl->flags & allowed)) {
if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
!(bctl->flags & BTRFS_BALANCE_METADATA) ||
memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
btrfs_err(fs_info,
"balance: mixed groups data and metadata options must be the same");
ret = -EINVAL;
goto out;
}
}
/*
* rw_devices will not change at the moment, device add/delete/replace
* are excluded by EXCL_OP
*/
num_devices = fs_info->fs_devices->rw_devices;
/*
* SINGLE profile on-disk has no profile bit, but in-memory we have a
* special bit for it, to make it easier to distinguish. Thus we need
* to set it manually, or balance would refuse the profile.
*/
allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++)
if (num_devices >= btrfs_raid_array[i].devs_min)
allowed |= btrfs_raid_array[i].bg_flag;
if (!validate_convert_profile(fs_info, &bctl->data, allowed, "data") ||
!validate_convert_profile(fs_info, &bctl->meta, allowed, "metadata") ||
!validate_convert_profile(fs_info, &bctl->sys, allowed, "system")) {
ret = -EINVAL;
goto out;
}
/*
* Allow to reduce metadata or system integrity only if force set for
* profiles with redundancy (copies, parity)
*/
allowed = 0;
for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) {
if (btrfs_raid_array[i].ncopies >= 2 ||
btrfs_raid_array[i].tolerated_failures >= 1)
allowed |= btrfs_raid_array[i].bg_flag;
}
do {
seq = read_seqbegin(&fs_info->profiles_lock);
if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_system_alloc_bits & allowed) &&
!(bctl->sys.target & allowed)) ||
((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_metadata_alloc_bits & allowed) &&
!(bctl->meta.target & allowed)))
reducing_redundancy = true;
else
reducing_redundancy = false;
/* if we're not converting, the target field is uninitialized */
meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
bctl->meta.target : fs_info->avail_metadata_alloc_bits;
data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
bctl->data.target : fs_info->avail_data_alloc_bits;
} while (read_seqretry(&fs_info->profiles_lock, seq));
if (reducing_redundancy) {
if (bctl->flags & BTRFS_BALANCE_FORCE) {
btrfs_info(fs_info,
"balance: force reducing metadata redundancy");
} else {
btrfs_err(fs_info,
"balance: reduces metadata redundancy, use --force if you want this");
ret = -EINVAL;
goto out;
}
}
if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
btrfs_warn(fs_info,
"balance: metadata profile %s has lower redundancy than data profile %s",
btrfs_bg_type_to_raid_name(meta_target),
btrfs_bg_type_to_raid_name(data_target));
}
if (fs_info->send_in_progress) {
btrfs_warn_rl(fs_info,
"cannot run balance while send operations are in progress (%d in progress)",
fs_info->send_in_progress);
ret = -EAGAIN;
goto out;
}
ret = insert_balance_item(fs_info, bctl);
if (ret && ret != -EEXIST)
goto out;
if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
BUG_ON(ret == -EEXIST);
BUG_ON(fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = bctl;
spin_unlock(&fs_info->balance_lock);
} else {
BUG_ON(ret != -EEXIST);
spin_lock(&fs_info->balance_lock);
update_balance_args(bctl);
spin_unlock(&fs_info->balance_lock);
}
ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
describe_balance_start_or_resume(fs_info);
mutex_unlock(&fs_info->balance_mutex);
ret = __btrfs_balance(fs_info);
mutex_lock(&fs_info->balance_mutex);
if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req))
btrfs_info(fs_info, "balance: paused");
/*
* Balance can be canceled by:
*
* - Regular cancel request
* Then ret == -ECANCELED and balance_cancel_req > 0
*
* - Fatal signal to "btrfs" process
* Either the signal caught by wait_reserve_ticket() and callers
* got -EINTR, or caught by btrfs_should_cancel_balance() and
* got -ECANCELED.
* Either way, in this case balance_cancel_req = 0, and
* ret == -EINTR or ret == -ECANCELED.
*
* So here we only check the return value to catch canceled balance.
*/
else if (ret == -ECANCELED || ret == -EINTR)
btrfs_info(fs_info, "balance: canceled");
else
btrfs_info(fs_info, "balance: ended with status: %d", ret);
clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
if (bargs) {
memset(bargs, 0, sizeof(*bargs));
btrfs_update_ioctl_balance_args(fs_info, bargs);
}
if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
balance_need_close(fs_info)) {
reset_balance_state(fs_info);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
}
wake_up(&fs_info->balance_wait_q);
return ret;
out:
if (bctl->flags & BTRFS_BALANCE_RESUME)
reset_balance_state(fs_info);
else
kfree(bctl);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
return ret;
}
static int balance_kthread(void *data)
{
struct btrfs_fs_info *fs_info = data;
int ret = 0;
mutex_lock(&fs_info->balance_mutex);
if (fs_info->balance_ctl)
ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);
mutex_unlock(&fs_info->balance_mutex);
return ret;
}
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
{
struct task_struct *tsk;
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return 0;
}
mutex_unlock(&fs_info->balance_mutex);
if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
btrfs_info(fs_info, "balance: resume skipped");
return 0;
}
/*
* A ro->rw remount sequence should continue with the paused balance
* regardless of who pauses it, system or the user as of now, so set
* the resume flag.
*/
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME;
spin_unlock(&fs_info->balance_lock);
tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
return PTR_ERR_OR_ZERO(tsk);
}
int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl;
struct btrfs_balance_item *item;
struct btrfs_disk_balance_args disk_bargs;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) { /* ret = -ENOENT; */
ret = 0;
goto out;
}
bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
if (!bctl) {
ret = -ENOMEM;
goto out;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
bctl->flags = btrfs_balance_flags(leaf, item);
bctl->flags |= BTRFS_BALANCE_RESUME;
btrfs_balance_data(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
btrfs_balance_meta(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
btrfs_balance_sys(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
/*
* This should never happen, as the paused balance state is recovered
* during mount without any chance of other exclusive ops to collide.
*
* This gives the exclusive op status to balance and keeps in paused
* state until user intervention (cancel or umount). If the ownership
* cannot be assigned, show a message but do not fail. The balance
* is in a paused state and must have fs_info::balance_ctl properly
* set up.
*/
if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
btrfs_warn(fs_info,
"balance: cannot set exclusive op status, resume manually");
mutex_lock(&fs_info->balance_mutex);
BUG_ON(fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = bctl;
spin_unlock(&fs_info->balance_lock);
mutex_unlock(&fs_info->balance_mutex);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
{
int ret = 0;
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return -ENOTCONN;
}
if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
atomic_inc(&fs_info->balance_pause_req);
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
/* we are good with balance_ctl ripped off from under us */
BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_pause_req);
} else {
ret = -ENOTCONN;
}
mutex_unlock(&fs_info->balance_mutex);
return ret;
}
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return -ENOTCONN;
}
/*
* A paused balance with the item stored on disk can be resumed at
* mount time if the mount is read-write. Otherwise it's still paused
* and we must not allow cancelling as it deletes the item.
*/
if (sb_rdonly(fs_info->sb)) {
mutex_unlock(&fs_info->balance_mutex);
return -EROFS;
}
atomic_inc(&fs_info->balance_cancel_req);
/*
* if we are running just wait and return, balance item is
* deleted in btrfs_balance in this case
*/
if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
} else {
mutex_unlock(&fs_info->balance_mutex);
/*
* Lock released to allow other waiters to continue, we'll
* reexamine the status again.
*/
mutex_lock(&fs_info->balance_mutex);
if (fs_info->balance_ctl) {
reset_balance_state(fs_info);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
btrfs_info(fs_info, "balance: canceled");
}
}
BUG_ON(fs_info->balance_ctl ||
test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_cancel_req);
mutex_unlock(&fs_info->balance_mutex);
return 0;
}
int btrfs_uuid_scan_kthread(void *data)
{
struct btrfs_fs_info *fs_info = data;
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_key key;
struct btrfs_path *path = NULL;
int ret = 0;
struct extent_buffer *eb;
int slot;
struct btrfs_root_item root_item;
u32 item_size;
struct btrfs_trans_handle *trans = NULL;
bool closing = false;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
key.objectid = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = 0;
while (1) {
if (btrfs_fs_closing(fs_info)) {
closing = true;
break;
}
ret = btrfs_search_forward(root, &key, path,
BTRFS_OLDEST_GENERATION);
if (ret) {
if (ret > 0)
ret = 0;
break;
}
if (key.type != BTRFS_ROOT_ITEM_KEY ||
(key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
key.objectid != BTRFS_FS_TREE_OBJECTID) ||
key.objectid > BTRFS_LAST_FREE_OBJECTID)
goto skip;
eb = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(eb, slot);
if (item_size < sizeof(root_item))
goto skip;
read_extent_buffer(eb, &root_item,
btrfs_item_ptr_offset(eb, slot),
(int)sizeof(root_item));
if (btrfs_root_refs(&root_item) == 0)
goto skip;
if (!btrfs_is_empty_uuid(root_item.uuid) ||
!btrfs_is_empty_uuid(root_item.received_uuid)) {
if (trans)
goto update_tree;
btrfs_release_path(path);
/*
* 1 - subvol uuid item
* 1 - received_subvol uuid item
*/
trans = btrfs_start_transaction(fs_info->uuid_root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
continue;
} else {
goto skip;
}
update_tree:
if (!btrfs_is_empty_uuid(root_item.uuid)) {
ret = btrfs_uuid_tree_add(trans, root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
key.objectid);
if (ret < 0) {
btrfs_warn(fs_info, "uuid_tree_add failed %d",
ret);
break;
}
}
if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
ret = btrfs_uuid_tree_add(trans,
root_item.received_uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
key.objectid);
if (ret < 0) {
btrfs_warn(fs_info, "uuid_tree_add failed %d",
ret);
break;
}
}
skip:
if (trans) {
ret = btrfs_end_transaction(trans);
trans = NULL;
if (ret)
break;
}
btrfs_release_path(path);
if (key.offset < (u64)-1) {
key.offset++;
} else if (key.type < BTRFS_ROOT_ITEM_KEY) {
key.offset = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
} else if (key.objectid < (u64)-1) {
key.offset = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
key.objectid++;
} else {
break;
}
cond_resched();
}
out:
btrfs_free_path(path);
if (trans && !IS_ERR(trans))
btrfs_end_transaction(trans);
if (ret)
btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
else if (!closing)
set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
up(&fs_info->uuid_tree_rescan_sem);
return 0;
}
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *uuid_root;
struct task_struct *task;
int ret;
/*
* 1 - root node
* 1 - root item
*/
trans = btrfs_start_transaction(tree_root, 2);
if (IS_ERR(trans))
return PTR_ERR(trans);
uuid_root = btrfs_create_tree(trans, BTRFS_UUID_TREE_OBJECTID);
if (IS_ERR(uuid_root)) {
ret = PTR_ERR(uuid_root);
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
return ret;
}
fs_info->uuid_root = uuid_root;
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
down(&fs_info->uuid_tree_rescan_sem);
task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
if (IS_ERR(task)) {
/* fs_info->update_uuid_tree_gen remains 0 in all error case */
btrfs_warn(fs_info, "failed to start uuid_scan task");
up(&fs_info->uuid_tree_rescan_sem);
return PTR_ERR(task);
}
return 0;
}
/*
* shrinking a device means finding all of the device extents past
* the new size, and then following the back refs to the chunks.
* The chunk relocation code actually frees the device extent
*/
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_trans_handle *trans;
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
u64 length;
u64 chunk_offset;
int ret;
int slot;
int failed = 0;
bool retried = false;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_super_block *super_copy = fs_info->super_copy;
u64 old_total = btrfs_super_total_bytes(super_copy);
u64 old_size = btrfs_device_get_total_bytes(device);
u64 diff;
u64 start;
new_size = round_down(new_size, fs_info->sectorsize);
start = new_size;
diff = round_down(old_size - new_size, fs_info->sectorsize);
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
return -EINVAL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_total_bytes(device, new_size);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
device->fs_devices->total_rw_bytes -= diff;
atomic64_sub(diff, &fs_info->free_chunk_space);
}
/*
* Once the device's size has been set to the new size, ensure all
* in-memory chunks are synced to disk so that the loop below sees them
* and relocates them accordingly.
*/
if (contains_pending_extent(device, &start, diff)) {
mutex_unlock(&fs_info->chunk_mutex);
ret = btrfs_commit_transaction(trans);
if (ret)
goto done;
} else {
mutex_unlock(&fs_info->chunk_mutex);
btrfs_end_transaction(trans);
}
again:
key.objectid = device->devid;
key.offset = (u64)-1;
key.type = BTRFS_DEV_EXTENT_KEY;
do {
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto done;
}
ret = btrfs_previous_item(root, path, 0, key.type);
if (ret)
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret < 0)
goto done;
if (ret) {
ret = 0;
btrfs_release_path(path);
break;
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
if (key.objectid != device->devid) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
btrfs_release_path(path);
break;
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
length = btrfs_dev_extent_length(l, dev_extent);
if (key.offset + length <= new_size) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
btrfs_release_path(path);
break;
}
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
btrfs_release_path(path);
/*
* We may be relocating the only data chunk we have,
* which could potentially end up with losing data's
* raid profile, so lets allocate an empty one in
* advance.
*/
ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto done;
}
ret = btrfs_relocate_chunk(fs_info, chunk_offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret == -ENOSPC) {
failed++;
} else if (ret) {
if (ret == -ETXTBSY) {
btrfs_warn(fs_info,
"could not shrink block group %llu due to active swapfile",
chunk_offset);
}
goto done;
}
} while (key.offset-- > 0);
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (failed && retried) {
ret = -ENOSPC;
goto done;
}
/* Shrinking succeeded, else we would be at "done". */
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto done;
}
mutex_lock(&fs_info->chunk_mutex);
/* Clear all state bits beyond the shrunk device size */
clear_extent_bits(&device->alloc_state, new_size, (u64)-1,
CHUNK_STATE_MASK);
btrfs_device_set_disk_total_bytes(device, new_size);
if (list_empty(&device->post_commit_list))
list_add_tail(&device->post_commit_list,
&trans->transaction->dev_update_list);
WARN_ON(diff > old_total);
btrfs_set_super_total_bytes(super_copy,
round_down(old_total - diff, fs_info->sectorsize));
mutex_unlock(&fs_info->chunk_mutex);
/* Now btrfs_update_device() will change the on-disk size. */
ret = btrfs_update_device(trans, device);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
} else {
ret = btrfs_commit_transaction(trans);
}
done:
btrfs_free_path(path);
if (ret) {
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_total_bytes(device, old_size);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
device->fs_devices->total_rw_bytes += diff;
atomic64_add(diff, &fs_info->free_chunk_space);
mutex_unlock(&fs_info->chunk_mutex);
}
return ret;
}
static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info,
struct btrfs_key *key,
struct btrfs_chunk *chunk, int item_size)
{
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct btrfs_disk_key disk_key;
u32 array_size;
u8 *ptr;
mutex_lock(&fs_info->chunk_mutex);
array_size = btrfs_super_sys_array_size(super_copy);
if (array_size + item_size + sizeof(disk_key)
> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
mutex_unlock(&fs_info->chunk_mutex);
return -EFBIG;
}
ptr = super_copy->sys_chunk_array + array_size;
btrfs_cpu_key_to_disk(&disk_key, key);
memcpy(ptr, &disk_key, sizeof(disk_key));
ptr += sizeof(disk_key);
memcpy(ptr, chunk, item_size);
item_size += sizeof(disk_key);
btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
mutex_unlock(&fs_info->chunk_mutex);
return 0;
}
/*
* sort the devices in descending order by max_avail, total_avail
*/
static int btrfs_cmp_device_info(const void *a, const void *b)
{
const struct btrfs_device_info *di_a = a;
const struct btrfs_device_info *di_b = b;
if (di_a->max_avail > di_b->max_avail)
return -1;
if (di_a->max_avail < di_b->max_avail)
return 1;
if (di_a->total_avail > di_b->total_avail)
return -1;
if (di_a->total_avail < di_b->total_avail)
return 1;
return 0;
}
static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
{
if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK))
return;
btrfs_set_fs_incompat(info, RAID56);
}
static void check_raid1c34_incompat_flag(struct btrfs_fs_info *info, u64 type)
{
if (!(type & (BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4)))
return;
btrfs_set_fs_incompat(info, RAID1C34);
}
/*
* Structure used internally for __btrfs_alloc_chunk() function.
* Wraps needed parameters.
*/
struct alloc_chunk_ctl {
u64 start;
u64 type;
/* Total number of stripes to allocate */
int num_stripes;
/* sub_stripes info for map */
int sub_stripes;
/* Stripes per device */
int dev_stripes;
/* Maximum number of devices to use */
int devs_max;
/* Minimum number of devices to use */
int devs_min;
/* ndevs has to be a multiple of this */
int devs_increment;
/* Number of copies */
int ncopies;
/* Number of stripes worth of bytes to store parity information */
int nparity;
u64 max_stripe_size;
u64 max_chunk_size;
u64 dev_extent_min;
u64 stripe_size;
u64 chunk_size;
int ndevs;
};
static void init_alloc_chunk_ctl_policy_regular(
struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl)
{
u64 type = ctl->type;
if (type & BTRFS_BLOCK_GROUP_DATA) {
ctl->max_stripe_size = SZ_1G;
ctl->max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
/* For larger filesystems, use larger metadata chunks */
if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
ctl->max_stripe_size = SZ_1G;
else
ctl->max_stripe_size = SZ_256M;
ctl->max_chunk_size = ctl->max_stripe_size;
} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
ctl->max_stripe_size = SZ_32M;
ctl->max_chunk_size = 2 * ctl->max_stripe_size;
ctl->devs_max = min_t(int, ctl->devs_max,
BTRFS_MAX_DEVS_SYS_CHUNK);
} else {
BUG();
}
/* We don't want a chunk larger than 10% of writable space */
ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
ctl->max_chunk_size);
ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
}
static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl)
{
int index = btrfs_bg_flags_to_raid_index(ctl->type);
ctl->sub_stripes = btrfs_raid_array[index].sub_stripes;
ctl->dev_stripes = btrfs_raid_array[index].dev_stripes;
ctl->devs_max = btrfs_raid_array[index].devs_max;
if (!ctl->devs_max)
ctl->devs_max = BTRFS_MAX_DEVS(fs_devices->fs_info);
ctl->devs_min = btrfs_raid_array[index].devs_min;
ctl->devs_increment = btrfs_raid_array[index].devs_increment;
ctl->ncopies = btrfs_raid_array[index].ncopies;
ctl->nparity = btrfs_raid_array[index].nparity;
ctl->ndevs = 0;
switch (fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
break;
default:
BUG();
}
}
static int gather_device_info(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = fs_devices->fs_info;
struct btrfs_device *device;
u64 total_avail;
u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes;
int ret;
int ndevs = 0;
u64 max_avail;
u64 dev_offset;
/*
* in the first pass through the devices list, we gather information
* about the available holes on each device.
*/
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
WARN(1, KERN_ERR
"BTRFS: read-only device in alloc_list\n");
continue;
}
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
continue;
if (device->total_bytes > device->bytes_used)
total_avail = device->total_bytes - device->bytes_used;
else
total_avail = 0;
/* If there is no space on this device, skip it. */
if (total_avail < ctl->dev_extent_min)
continue;
ret = find_free_dev_extent(device, dev_extent_want, &dev_offset,
&max_avail);
if (ret && ret != -ENOSPC)
return ret;
if (ret == 0)
max_avail = dev_extent_want;
if (max_avail < ctl->dev_extent_min) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info,
"%s: devid %llu has no free space, have=%llu want=%llu",
__func__, device->devid, max_avail,
ctl->dev_extent_min);
continue;
}
if (ndevs == fs_devices->rw_devices) {
WARN(1, "%s: found more than %llu devices\n",
__func__, fs_devices->rw_devices);
break;
}
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
}
ctl->ndevs = ndevs;
/*
* now sort the devices by hole size / available space
*/
sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
btrfs_cmp_device_info, NULL);
return 0;
}
static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
/* Number of stripes that count for block group size */
int data_stripes;
/*
* The primary goal is to maximize the number of stripes, so use as
* many devices as possible, even if the stripes are not maximum sized.
*
* The DUP profile stores more than one stripe per device, the
* max_avail is the total size so we have to adjust.
*/
ctl->stripe_size = div_u64(devices_info[ctl->ndevs - 1].max_avail,
ctl->dev_stripes);
ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
/* This will have to be fixed for RAID1 and RAID10 over more drives */
data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
/*
* Use the number of data stripes to figure out how big this chunk is
* really going to be in terms of logical address space, and compare
* that answer with the max chunk size. If it's higher, we try to
* reduce stripe_size.
*/
if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
/*
* Reduce stripe_size, round it up to a 16MB boundary again and
* then use it, unless it ends up being even bigger than the
* previous value we had already.
*/
ctl->stripe_size = min(round_up(div_u64(ctl->max_chunk_size,
data_stripes), SZ_16M),
ctl->stripe_size);
}
/* Align to BTRFS_STRIPE_LEN */
ctl->stripe_size = round_down(ctl->stripe_size, BTRFS_STRIPE_LEN);
ctl->chunk_size = ctl->stripe_size * data_stripes;
return 0;
}
static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = fs_devices->fs_info;
/*
* Round down to number of usable stripes, devs_increment can be any
* number so we can't use round_down() that requires power of 2, while
* rounddown is safe.
*/
ctl->ndevs = rounddown(ctl->ndevs, ctl->devs_increment);
if (ctl->ndevs < ctl->devs_min) {
if (btrfs_test_opt(info, ENOSPC_DEBUG)) {
btrfs_debug(info,
"%s: not enough devices with free space: have=%d minimum required=%d",
__func__, ctl->ndevs, ctl->devs_min);
}
return -ENOSPC;
}
ctl->ndevs = min(ctl->ndevs, ctl->devs_max);
switch (fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
return decide_stripe_size_regular(ctl, devices_info);
default:
BUG();
}
}
static int create_chunk(struct btrfs_trans_handle *trans,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = trans->fs_info;
struct map_lookup *map = NULL;
struct extent_map_tree *em_tree;
struct extent_map *em;
u64 start = ctl->start;
u64 type = ctl->type;
int ret;
int i;
int j;
map = kmalloc(map_lookup_size(ctl->num_stripes), GFP_NOFS);
if (!map)
return -ENOMEM;
map->num_stripes = ctl->num_stripes;
for (i = 0; i < ctl->ndevs; ++i) {
for (j = 0; j < ctl->dev_stripes; ++j) {
int s = i * ctl->dev_stripes + j;
map->stripes[s].dev = devices_info[i].dev;
map->stripes[s].physical = devices_info[i].dev_offset +
j * ctl->stripe_size;
}
}
map->stripe_len = BTRFS_STRIPE_LEN;
map->io_align = BTRFS_STRIPE_LEN;
map->io_width = BTRFS_STRIPE_LEN;
map->type = type;
map->sub_stripes = ctl->sub_stripes;
trace_btrfs_chunk_alloc(info, map, start, ctl->chunk_size);
em = alloc_extent_map();
if (!em) {
kfree(map);
return -ENOMEM;
}
set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
em->map_lookup = map;
em->start = start;
em->len = ctl->chunk_size;
em->block_start = 0;
em->block_len = em->len;
em->orig_block_len = ctl->stripe_size;
em_tree = &info->mapping_tree;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 0);
if (ret) {
write_unlock(&em_tree->lock);
free_extent_map(em);
return ret;
}
write_unlock(&em_tree->lock);
ret = btrfs_make_block_group(trans, 0, type, start, ctl->chunk_size);
if (ret)
goto error_del_extent;
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *dev = map->stripes[i].dev;
btrfs_device_set_bytes_used(dev,
dev->bytes_used + ctl->stripe_size);
if (list_empty(&dev->post_commit_list))
list_add_tail(&dev->post_commit_list,
&trans->transaction->dev_update_list);
}
atomic64_sub(ctl->stripe_size * map->num_stripes,
&info->free_chunk_space);
free_extent_map(em);
check_raid56_incompat_flag(info, type);
check_raid1c34_incompat_flag(info, type);
return 0;
error_del_extent:
write_lock(&em_tree->lock);
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
/* One for our allocation */
free_extent_map(em);
/* One for the tree reference */
free_extent_map(em);
return ret;
}
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type)
{
struct btrfs_fs_info *info = trans->fs_info;
struct btrfs_fs_devices *fs_devices = info->fs_devices;
struct btrfs_device_info *devices_info = NULL;
struct alloc_chunk_ctl ctl;
int ret;
lockdep_assert_held(&info->chunk_mutex);
if (!alloc_profile_is_valid(type, 0)) {
ASSERT(0);
return -EINVAL;
}
if (list_empty(&fs_devices->alloc_list)) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info, "%s: no writable device", __func__);
return -ENOSPC;
}
if (!(type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
btrfs_err(info, "invalid chunk type 0x%llx requested", type);
ASSERT(0);
return -EINVAL;
}
ctl.start = find_next_chunk(info);
ctl.type = type;
init_alloc_chunk_ctl(fs_devices, &ctl);
devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info),
GFP_NOFS);
if (!devices_info)
return -ENOMEM;
ret = gather_device_info(fs_devices, &ctl, devices_info);
if (ret < 0)
goto out;
ret = decide_stripe_size(fs_devices, &ctl, devices_info);
if (ret < 0)
goto out;
ret = create_chunk(trans, &ctl, devices_info);
out:
kfree(devices_info);
return ret;
}
/*
* Chunk allocation falls into two parts. The first part does work
* that makes the new allocated chunk usable, but does not do any operation
* that modifies the chunk tree. The second part does the work that
* requires modifying the chunk tree. This division is important for the
* bootstrap process of adding storage to a seed btrfs.
*/
int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
u64 chunk_offset, u64 chunk_size)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *extent_root = fs_info->extent_root;
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_key key;
struct btrfs_device *device;
struct btrfs_chunk *chunk;
struct btrfs_stripe *stripe;
struct extent_map *em;
struct map_lookup *map;
size_t item_size;
u64 dev_offset;
u64 stripe_size;
int i = 0;
int ret = 0;
em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
item_size = btrfs_chunk_item_size(map->num_stripes);
stripe_size = em->orig_block_len;
chunk = kzalloc(item_size, GFP_NOFS);
if (!chunk) {
ret = -ENOMEM;
goto out;
}
/*
* Take the device list mutex to prevent races with the final phase of
* a device replace operation that replaces the device object associated
* with the map's stripes, because the device object's id can change
* at any time during that final phase of the device replace operation
* (dev-replace.c:btrfs_dev_replace_finishing()).
*/
mutex_lock(&fs_info->fs_devices->device_list_mutex);
for (i = 0; i < map->num_stripes; i++) {
device = map->stripes[i].dev;
dev_offset = map->stripes[i].physical;
ret = btrfs_update_device(trans, device);
if (ret)
break;
ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
dev_offset, stripe_size);
if (ret)
break;
}
if (ret) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
goto out;
}
stripe = &chunk->stripe;
for (i = 0; i < map->num_stripes; i++) {
device = map->stripes[i].dev;
dev_offset = map->stripes[i].physical;
btrfs_set_stack_stripe_devid(stripe, device->devid);
btrfs_set_stack_stripe_offset(stripe, dev_offset);
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
stripe++;
}
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_set_stack_chunk_length(chunk, chunk_size);
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
btrfs_set_stack_chunk_type(chunk, map->type);
btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize);
btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
key.offset = chunk_offset;
ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
/*
* TODO: Cleanup of inserted chunk root in case of
* failure.
*/
ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size);
}
out:
kfree(chunk);
free_extent_map(em);
return ret;
}
static noinline int init_first_rw_device(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
u64 alloc_profile;
int ret;
alloc_profile = btrfs_metadata_alloc_profile(fs_info);
ret = btrfs_alloc_chunk(trans, alloc_profile);
if (ret)
return ret;
alloc_profile = btrfs_system_alloc_profile(fs_info);
ret = btrfs_alloc_chunk(trans, alloc_profile);
return ret;
}
static inline int btrfs_chunk_max_errors(struct map_lookup *map)
{
const int index = btrfs_bg_flags_to_raid_index(map->type);
return btrfs_raid_array[index].tolerated_failures;
}
int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct extent_map *em;
struct map_lookup *map;
int readonly = 0;
int miss_ndevs = 0;
int i;
em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
if (IS_ERR(em))
return 1;
map = em->map_lookup;
for (i = 0; i < map->num_stripes; i++) {
if (test_bit(BTRFS_DEV_STATE_MISSING,
&map->stripes[i].dev->dev_state)) {
miss_ndevs++;
continue;
}
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE,
&map->stripes[i].dev->dev_state)) {
readonly = 1;
goto end;
}
}
/*
* If the number of missing devices is larger than max errors,
* we can not write the data into that chunk successfully, so
* set it readonly.
*/
if (miss_ndevs > btrfs_chunk_max_errors(map))
readonly = 1;
end:
free_extent_map(em);
return readonly;
}
void btrfs_mapping_tree_free(struct extent_map_tree *tree)
{
struct extent_map *em;
while (1) {
write_lock(&tree->lock);
em = lookup_extent_mapping(tree, 0, (u64)-1);
if (em)
remove_extent_mapping(tree, em);
write_unlock(&tree->lock);
if (!em)
break;
/* once for us */
free_extent_map(em);
/* once for the tree */
free_extent_map(em);
}
}
int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
{
struct extent_map *em;
struct map_lookup *map;
int ret;
em = btrfs_get_chunk_map(fs_info, logical, len);
if (IS_ERR(em))
/*
* We could return errors for these cases, but that could get
* ugly and we'd probably do the same thing which is just not do
* anything else and exit, so return 1 so the callers don't try
* to use other copies.
*/
return 1;
map = em->map_lookup;
if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1_MASK))
ret = map->num_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
ret = map->sub_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
ret = 2;
else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
/*
* There could be two corrupted data stripes, we need
* to loop retry in order to rebuild the correct data.
*
* Fail a stripe at a time on every retry except the
* stripe under reconstruction.
*/
ret = map->num_stripes;
else
ret = 1;
free_extent_map(em);
down_read(&fs_info->dev_replace.rwsem);
if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
fs_info->dev_replace.tgtdev)
ret++;
up_read(&fs_info->dev_replace.rwsem);
return ret;
}
unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
u64 logical)
{
struct extent_map *em;
struct map_lookup *map;
unsigned long len = fs_info->sectorsize;
em = btrfs_get_chunk_map(fs_info, logical, len);
if (!WARN_ON(IS_ERR(em))) {
map = em->map_lookup;
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
len = map->stripe_len * nr_data_stripes(map);
free_extent_map(em);
}
return len;
}
int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
{
struct extent_map *em;
struct map_lookup *map;
int ret = 0;
em = btrfs_get_chunk_map(fs_info, logical, len);
if(!WARN_ON(IS_ERR(em))) {
map = em->map_lookup;
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
ret = 1;
free_extent_map(em);
}
return ret;
}
static int find_live_mirror(struct btrfs_fs_info *fs_info,
struct map_lookup *map, int first,
int dev_replace_is_ongoing)
{
int i;
int num_stripes;
int preferred_mirror;
int tolerance;
struct btrfs_device *srcdev;
ASSERT((map->type &
(BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10)));
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
num_stripes = map->sub_stripes;
else
num_stripes = map->num_stripes;
preferred_mirror = first + current->pid % num_stripes;
if (dev_replace_is_ongoing &&
fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
srcdev = fs_info->dev_replace.srcdev;
else
srcdev = NULL;
/*
* try to avoid the drive that is the source drive for a
* dev-replace procedure, only choose it if no other non-missing
* mirror is available
*/
for (tolerance = 0; tolerance < 2; tolerance++) {
if (map->stripes[preferred_mirror].dev->bdev &&
(tolerance || map->stripes[preferred_mirror].dev != srcdev))
return preferred_mirror;
for (i = first; i < first + num_stripes; i++) {
if (map->stripes[i].dev->bdev &&
(tolerance || map->stripes[i].dev != srcdev))
return i;
}
}
/* we couldn't find one that doesn't fail. Just return something
* and the io error handling code will clean up eventually
*/
return preferred_mirror;
}
/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes)
{
int i;
int again = 1;
while (again) {
again = 0;
for (i = 0; i < num_stripes - 1; i++) {
/* Swap if parity is on a smaller index */
if (bbio->raid_map[i] > bbio->raid_map[i + 1]) {
swap(bbio->stripes[i], bbio->stripes[i + 1]);
swap(bbio->raid_map[i], bbio->raid_map[i + 1]);
again = 1;
}
}
}
}
static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
{
struct btrfs_bio *bbio = kzalloc(
/* the size of the btrfs_bio */
sizeof(struct btrfs_bio) +
/* plus the variable array for the stripes */
sizeof(struct btrfs_bio_stripe) * (total_stripes) +
/* plus the variable array for the tgt dev */
sizeof(int) * (real_stripes) +
/*
* plus the raid_map, which includes both the tgt dev
* and the stripes
*/
sizeof(u64) * (total_stripes),
GFP_NOFS|__GFP_NOFAIL);
atomic_set(&bbio->error, 0);
refcount_set(&bbio->refs, 1);
bbio->tgtdev_map = (int *)(bbio->stripes + total_stripes);
bbio->raid_map = (u64 *)(bbio->tgtdev_map + real_stripes);
return bbio;
}
void btrfs_get_bbio(struct btrfs_bio *bbio)
{
WARN_ON(!refcount_read(&bbio->refs));
refcount_inc(&bbio->refs);
}
void btrfs_put_bbio(struct btrfs_bio *bbio)
{
if (!bbio)
return;
if (refcount_dec_and_test(&bbio->refs))
kfree(bbio);
}
/* can REQ_OP_DISCARD be sent with other REQ like REQ_OP_WRITE? */
/*
* Please note that, discard won't be sent to target device of device
* replace.
*/
static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
u64 logical, u64 *length_ret,
struct btrfs_bio **bbio_ret)
{
struct extent_map *em;
struct map_lookup *map;
struct btrfs_bio *bbio;
u64 length = *length_ret;
u64 offset;
u64 stripe_nr;
u64 stripe_nr_end;
u64 stripe_end_offset;
u64 stripe_cnt;
u64 stripe_len;
u64 stripe_offset;
u64 num_stripes;
u32 stripe_index;
u32 factor = 0;
u32 sub_stripes = 0;
u64 stripes_per_dev = 0;
u32 remaining_stripes = 0;
u32 last_stripe = 0;
int ret = 0;
int i;
/* discard always return a bbio */
ASSERT(bbio_ret);
em = btrfs_get_chunk_map(fs_info, logical, length);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
/* we don't discard raid56 yet */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
ret = -EOPNOTSUPP;
goto out;
}
offset = logical - em->start;
length = min_t(u64, em->start + em->len - logical, length);
*length_ret = length;
stripe_len = map->stripe_len;
/*
* stripe_nr counts the total number of stripes we have to stride
* to get to this block
*/
stripe_nr = div64_u64(offset, stripe_len);
/* stripe_offset is the offset of this block in its stripe */
stripe_offset = offset - stripe_nr * stripe_len;
stripe_nr_end = round_up(offset + length, map->stripe_len);
stripe_nr_end = div64_u64(stripe_nr_end, map->stripe_len);
stripe_cnt = stripe_nr_end - stripe_nr;
stripe_end_offset = stripe_nr_end * map->stripe_len -
(offset + length);
/*
* after this, stripe_nr is the number of stripes on this
* device we have to walk to find the data, and stripe_index is
* the number of our device in the stripe array
*/
num_stripes = 1;
stripe_index = 0;
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10)) {
if (map->type & BTRFS_BLOCK_GROUP_RAID0)
sub_stripes = 1;
else
sub_stripes = map->sub_stripes;
factor = map->num_stripes / sub_stripes;
num_stripes = min_t(u64, map->num_stripes,
sub_stripes * stripe_cnt);
stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
stripe_index *= sub_stripes;
stripes_per_dev = div_u64_rem(stripe_cnt, factor,
&remaining_stripes);
div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
last_stripe *= sub_stripes;
} else if (map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK |
BTRFS_BLOCK_GROUP_DUP)) {
num_stripes = map->num_stripes;
} else {
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
}
bbio = alloc_btrfs_bio(num_stripes, 0);
if (!bbio) {
ret = -ENOMEM;
goto out;
}
for (i = 0; i < num_stripes; i++) {
bbio->stripes[i].physical =
map->stripes[stripe_index].physical +
stripe_offset + stripe_nr * map->stripe_len;
bbio->stripes[i].dev = map->stripes[stripe_index].dev;
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10)) {
bbio->stripes[i].length = stripes_per_dev *
map->stripe_len;
if (i / sub_stripes < remaining_stripes)
bbio->stripes[i].length +=
map->stripe_len;
/*
* Special for the first stripe and
* the last stripe:
*
* |-------|...|-------|
* |----------|
* off end_off
*/
if (i < sub_stripes)
bbio->stripes[i].length -=
stripe_offset;
if (stripe_index >= last_stripe &&
stripe_index <= (last_stripe +
sub_stripes - 1))
bbio->stripes[i].length -=
stripe_end_offset;
if (i == sub_stripes - 1)
stripe_offset = 0;
} else {
bbio->stripes[i].length = length;
}
stripe_index++;
if (stripe_index == map->num_stripes) {
stripe_index = 0;
stripe_nr++;
}
}
*bbio_ret = bbio;
bbio->map_type = map->type;
bbio->num_stripes = num_stripes;
out:
free_extent_map(em);
return ret;
}
/*
* In dev-replace case, for repair case (that's the only case where the mirror
* is selected explicitly when calling btrfs_map_block), blocks left of the
* left cursor can also be read from the target drive.
*
* For REQ_GET_READ_MIRRORS, the target drive is added as the last one to the
* array of stripes.
* For READ, it also needs to be supported using the same mirror number.
*
* If the requested block is not left of the left cursor, EIO is returned. This
* can happen because btrfs_num_copies() returns one more in the dev-replace
* case.
*/
static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
u64 logical, u64 length,
u64 srcdev_devid, int *mirror_num,
u64 *physical)
{
struct btrfs_bio *bbio = NULL;
int num_stripes;
int index_srcdev = 0;
int found = 0;
u64 physical_of_found = 0;
int i;
int ret = 0;
ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
logical, &length, &bbio, 0, 0);
if (ret) {
ASSERT(bbio == NULL);
return ret;
}
num_stripes = bbio->num_stripes;
if (*mirror_num > num_stripes) {
/*
* BTRFS_MAP_GET_READ_MIRRORS does not contain this mirror,
* that means that the requested area is not left of the left
* cursor
*/
btrfs_put_bbio(bbio);
return -EIO;
}
/*
* process the rest of the function using the mirror_num of the source
* drive. Therefore look it up first. At the end, patch the device
* pointer to the one of the target drive.
*/
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid != srcdev_devid)
continue;
/*
* In case of DUP, in order to keep it simple, only add the
* mirror with the lowest physical address
*/
if (found &&
physical_of_found <= bbio->stripes[i].physical)
continue;
index_srcdev = i;
found = 1;
physical_of_found = bbio->stripes[i].physical;
}
btrfs_put_bbio(bbio);
ASSERT(found);
if (!found)
return -EIO;
*mirror_num = index_srcdev + 1;
*physical = physical_of_found;
return ret;
}
static void handle_ops_on_dev_replace(enum btrfs_map_op op,
struct btrfs_bio **bbio_ret,
struct btrfs_dev_replace *dev_replace,
int *num_stripes_ret, int *max_errors_ret)
{
struct btrfs_bio *bbio = *bbio_ret;
u64 srcdev_devid = dev_replace->srcdev->devid;
int tgtdev_indexes = 0;
int num_stripes = *num_stripes_ret;
int max_errors = *max_errors_ret;
int i;
if (op == BTRFS_MAP_WRITE) {
int index_where_to_add;
/*
* duplicate the write operations while the dev replace
* procedure is running. Since the copying of the old disk to
* the new disk takes place at run time while the filesystem is
* mounted writable, the regular write operations to the old
* disk have to be duplicated to go to the new disk as well.
*
* Note that device->missing is handled by the caller, and that
* the write to the old disk is already set up in the stripes
* array.
*/
index_where_to_add = num_stripes;
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid == srcdev_devid) {
/* write to new disk, too */
struct btrfs_bio_stripe *new =
bbio->stripes + index_where_to_add;
struct btrfs_bio_stripe *old =
bbio->stripes + i;
new->physical = old->physical;
new->length = old->length;
new->dev = dev_replace->tgtdev;
bbio->tgtdev_map[i] = index_where_to_add;
index_where_to_add++;
max_errors++;
tgtdev_indexes++;
}
}
num_stripes = index_where_to_add;
} else if (op == BTRFS_MAP_GET_READ_MIRRORS) {
int index_srcdev = 0;
int found = 0;
u64 physical_of_found = 0;
/*
* During the dev-replace procedure, the target drive can also
* be used to read data in case it is needed to repair a corrupt
* block elsewhere. This is possible if the requested area is
* left of the left cursor. In this area, the target drive is a
* full copy of the source drive.
*/
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid == srcdev_devid) {
/*
* In case of DUP, in order to keep it simple,
* only add the mirror with the lowest physical
* address
*/
if (found &&
physical_of_found <=
bbio->stripes[i].physical)
continue;
index_srcdev = i;
found = 1;
physical_of_found = bbio->stripes[i].physical;
}
}
if (found) {
struct btrfs_bio_stripe *tgtdev_stripe =
bbio->stripes + num_stripes;
tgtdev_stripe->physical = physical_of_found;
tgtdev_stripe->length =
bbio->stripes[index_srcdev].length;
tgtdev_stripe->dev = dev_replace->tgtdev;
bbio->tgtdev_map[index_srcdev] = num_stripes;
tgtdev_indexes++;
num_stripes++;
}
}
*num_stripes_ret = num_stripes;
*max_errors_ret = max_errors;
bbio->num_tgtdevs = tgtdev_indexes;
*bbio_ret = bbio;
}
static bool need_full_stripe(enum btrfs_map_op op)
{
return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
}
/*
* btrfs_get_io_geometry - calculates the geomery of a particular (address, len)
* tuple. This information is used to calculate how big a
* particular bio can get before it straddles a stripe.
*
* @fs_info - the filesystem
* @logical - address that we want to figure out the geometry of
* @len - the length of IO we are going to perform, starting at @logical
* @op - type of operation - write or read
* @io_geom - pointer used to return values
*
* Returns < 0 in case a chunk for the given logical address cannot be found,
* usually shouldn't happen unless @logical is corrupted, 0 otherwise.
*/
int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 len, struct btrfs_io_geometry *io_geom)
{
struct extent_map *em;
struct map_lookup *map;
u64 offset;
u64 stripe_offset;
u64 stripe_nr;
u64 stripe_len;
u64 raid56_full_stripe_start = (u64)-1;
int data_stripes;
int ret = 0;
ASSERT(op != BTRFS_MAP_DISCARD);
em = btrfs_get_chunk_map(fs_info, logical, len);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
/* Offset of this logical address in the chunk */
offset = logical - em->start;
/* Len of a stripe in a chunk */
stripe_len = map->stripe_len;
/* Stripe wher this block falls in */
stripe_nr = div64_u64(offset, stripe_len);
/* Offset of stripe in the chunk */
stripe_offset = stripe_nr * stripe_len;
if (offset < stripe_offset) {
btrfs_crit(fs_info,
"stripe math has gone wrong, stripe_offset=%llu offset=%llu start=%llu logical=%llu stripe_len=%llu",
stripe_offset, offset, em->start, logical, stripe_len);
ret = -EINVAL;
goto out;
}
/* stripe_offset is the offset of this block in its stripe */
stripe_offset = offset - stripe_offset;
data_stripes = nr_data_stripes(map);
if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
u64 max_len = stripe_len - stripe_offset;
/*
* In case of raid56, we need to know the stripe aligned start
*/
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
unsigned long full_stripe_len = stripe_len * data_stripes;
raid56_full_stripe_start = offset;
/*
* Allow a write of a full stripe, but make sure we
* don't allow straddling of stripes
*/
raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
full_stripe_len);
raid56_full_stripe_start *= full_stripe_len;
/*
* For writes to RAID[56], allow a full stripeset across
* all disks. For other RAID types and for RAID[56]
* reads, just allow a single stripe (on a single disk).
*/
if (op == BTRFS_MAP_WRITE) {
max_len = stripe_len * data_stripes -
(offset - raid56_full_stripe_start);
}
}
len = min_t(u64, em->len - offset, max_len);
} else {
len = em->len - offset;
}
io_geom->len = len;
io_geom->offset = offset;
io_geom->stripe_len = stripe_len;
io_geom->stripe_nr = stripe_nr;
io_geom->stripe_offset = stripe_offset;
io_geom->raid56_stripe_offset = raid56_full_stripe_start;
out:
/* once for us */
free_extent_map(em);
return ret;
}
static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret,
int mirror_num, int need_raid_map)
{
struct extent_map *em;
struct map_lookup *map;
u64 stripe_offset;
u64 stripe_nr;
u64 stripe_len;
u32 stripe_index;
int data_stripes;
int i;
int ret = 0;
int num_stripes;
int max_errors = 0;
int tgtdev_indexes = 0;
struct btrfs_bio *bbio = NULL;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
int dev_replace_is_ongoing = 0;
int num_alloc_stripes;
int patch_the_first_stripe_for_dev_replace = 0;
u64 physical_to_patch_in_first_stripe = 0;
u64 raid56_full_stripe_start = (u64)-1;
struct btrfs_io_geometry geom;
ASSERT(bbio_ret);
ASSERT(op != BTRFS_MAP_DISCARD);
ret = btrfs_get_io_geometry(fs_info, op, logical, *length, &geom);
if (ret < 0)
return ret;
em = btrfs_get_chunk_map(fs_info, logical, *length);
ASSERT(!IS_ERR(em));
map = em->map_lookup;
*length = geom.len;
stripe_len = geom.stripe_len;
stripe_nr = geom.stripe_nr;
stripe_offset = geom.stripe_offset;
raid56_full_stripe_start = geom.raid56_stripe_offset;
data_stripes = nr_data_stripes(map);
down_read(&dev_replace->rwsem);
dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
/*
* Hold the semaphore for read during the whole operation, write is
* requested at commit time but must wait.
*/
if (!dev_replace_is_ongoing)
up_read(&dev_replace->rwsem);
if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
!need_full_stripe(op) && dev_replace->tgtdev != NULL) {
ret = get_extra_mirror_from_replace(fs_info, logical, *length,
dev_replace->srcdev->devid,
&mirror_num,
&physical_to_patch_in_first_stripe);
if (ret)
goto out;
else
patch_the_first_stripe_for_dev_replace = 1;
} else if (mirror_num > map->num_stripes) {
mirror_num = 0;
}
num_stripes = 1;
stripe_index = 0;
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
if (!need_full_stripe(op))
mirror_num = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
if (need_full_stripe(op))
num_stripes = map->num_stripes;
else if (mirror_num)
stripe_index = mirror_num - 1;
else {
stripe_index = find_live_mirror(fs_info, map, 0,
dev_replace_is_ongoing);
mirror_num = stripe_index + 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
if (need_full_stripe(op)) {
num_stripes = map->num_stripes;
} else if (mirror_num) {
stripe_index = mirror_num - 1;
} else {
mirror_num = 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
u32 factor = map->num_stripes / map->sub_stripes;
stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
stripe_index *= map->sub_stripes;
if (need_full_stripe(op))
num_stripes = map->sub_stripes;
else if (mirror_num)
stripe_index += mirror_num - 1;
else {
int old_stripe_index = stripe_index;
stripe_index = find_live_mirror(fs_info, map,
stripe_index,
dev_replace_is_ongoing);
mirror_num = stripe_index - old_stripe_index + 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
/* push stripe_nr back to the start of the full stripe */
stripe_nr = div64_u64(raid56_full_stripe_start,
stripe_len * data_stripes);
/* RAID[56] write or recovery. Return all stripes */
num_stripes = map->num_stripes;
max_errors = nr_parity_stripes(map);
*length = map->stripe_len;
stripe_index = 0;
stripe_offset = 0;
} else {
/*
* Mirror #0 or #1 means the original data block.
* Mirror #2 is RAID5 parity block.
* Mirror #3 is RAID6 Q block.
*/
stripe_nr = div_u64_rem(stripe_nr,
data_stripes, &stripe_index);
if (mirror_num > 1)
stripe_index = data_stripes + mirror_num - 2;
/* We distribute the parity blocks across stripes */
div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
&stripe_index);
if (!need_full_stripe(op) && mirror_num <= 1)
mirror_num = 1;
}
} else {
/*
* after this, stripe_nr is the number of stripes on this
* device we have to walk to find the data, and stripe_index is
* the number of our device in the stripe array
*/
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
mirror_num = stripe_index + 1;
}
if (stripe_index >= map->num_stripes) {
btrfs_crit(fs_info,
"stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u",
stripe_index, map->num_stripes);
ret = -EINVAL;
goto out;
}
num_alloc_stripes = num_stripes;
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) {
if (op == BTRFS_MAP_WRITE)
num_alloc_stripes <<= 1;
if (op == BTRFS_MAP_GET_READ_MIRRORS)
num_alloc_stripes++;
tgtdev_indexes = num_stripes;
}
bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes);
if (!bbio) {
ret = -ENOMEM;
goto out;
}
for (i = 0; i < num_stripes; i++) {
bbio->stripes[i].physical = map->stripes[stripe_index].physical +
stripe_offset + stripe_nr * map->stripe_len;
bbio->stripes[i].dev = map->stripes[stripe_index].dev;
stripe_index++;
}
/* build raid_map */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
(need_full_stripe(op) || mirror_num > 1)) {
u64 tmp;
unsigned rot;
/* Work out the disk rotation on this stripe-set */
div_u64_rem(stripe_nr, num_stripes, &rot);
/* Fill in the logical address of each stripe */
tmp = stripe_nr * data_stripes;
for (i = 0; i < data_stripes; i++)
bbio->raid_map[(i+rot) % num_stripes] =
em->start + (tmp + i) * map->stripe_len;
bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
if (map->type & BTRFS_BLOCK_GROUP_RAID6)
bbio->raid_map[(i+rot+1) % num_stripes] =
RAID6_Q_STRIPE;
sort_parity_stripes(bbio, num_stripes);
}
if (need_full_stripe(op))
max_errors = btrfs_chunk_max_errors(map);
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
need_full_stripe(op)) {
handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
&max_errors);
}
*bbio_ret = bbio;
bbio->map_type = map->type;
bbio->num_stripes = num_stripes;
bbio->max_errors = max_errors;
bbio->mirror_num = mirror_num;
/*
* this is the case that REQ_READ && dev_replace_is_ongoing &&
* mirror_num == num_stripes + 1 && dev_replace target drive is
* available as a mirror
*/
if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
WARN_ON(num_stripes > 1);
bbio->stripes[0].dev = dev_replace->tgtdev;
bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
bbio->mirror_num = map->num_stripes + 1;
}
out:
if (dev_replace_is_ongoing) {
lockdep_assert_held(&dev_replace->rwsem);
/* Unlock and let waiting writers proceed */
up_read(&dev_replace->rwsem);
}
free_extent_map(em);
return ret;
}
int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret, int mirror_num)
{
if (op == BTRFS_MAP_DISCARD)
return __btrfs_map_block_for_discard(fs_info, logical,
length, bbio_ret);
return __btrfs_map_block(fs_info, op, logical, length, bbio_ret,
mirror_num, 0);
}
/* For Scrub/replace */
int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret)
{
return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1);
}
static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
{
bio->bi_private = bbio->private;
bio->bi_end_io = bbio->end_io;
bio_endio(bio);
btrfs_put_bbio(bbio);
}
static void btrfs_end_bio(struct bio *bio)
{
struct btrfs_bio *bbio = bio->bi_private;
int is_orig_bio = 0;
if (bio->bi_status) {
atomic_inc(&bbio->error);
if (bio->bi_status == BLK_STS_IOERR ||
bio->bi_status == BLK_STS_TARGET) {
struct btrfs_device *dev = btrfs_io_bio(bio)->device;
ASSERT(dev->bdev);
if (bio_op(bio) == REQ_OP_WRITE)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_WRITE_ERRS);
else if (!(bio->bi_opf & REQ_RAHEAD))
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_READ_ERRS);
if (bio->bi_opf & REQ_PREFLUSH)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_FLUSH_ERRS);
}
}
if (bio == bbio->orig_bio)
is_orig_bio = 1;
btrfs_bio_counter_dec(bbio->fs_info);
if (atomic_dec_and_test(&bbio->stripes_pending)) {
if (!is_orig_bio) {
bio_put(bio);
bio = bbio->orig_bio;
}
btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
/* only send an error to the higher layers if it is
* beyond the tolerance of the btrfs bio
*/
if (atomic_read(&bbio->error) > bbio->max_errors) {
bio->bi_status = BLK_STS_IOERR;
} else {
/*
* this bio is actually up to date, we didn't
* go over the max number of errors
*/
bio->bi_status = BLK_STS_OK;
}
btrfs_end_bbio(bbio, bio);
} else if (!is_orig_bio) {
bio_put(bio);
}
}
static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
u64 physical, struct btrfs_device *dev)
{
struct btrfs_fs_info *fs_info = bbio->fs_info;
bio->bi_private = bbio;
btrfs_io_bio(bio)->device = dev;
bio->bi_end_io = btrfs_end_bio;
bio->bi_iter.bi_sector = physical >> 9;
btrfs_debug_in_rcu(fs_info,
"btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector,
(unsigned long)dev->bdev->bd_dev, rcu_str_deref(dev->name),
dev->devid, bio->bi_iter.bi_size);
bio_set_dev(bio, dev->bdev);
btrfs_bio_counter_inc_noblocked(fs_info);
btrfsic_submit_bio(bio);
}
static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
{
atomic_inc(&bbio->error);
if (atomic_dec_and_test(&bbio->stripes_pending)) {
/* Should be the original bio. */
WARN_ON(bio != bbio->orig_bio);
btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
bio->bi_iter.bi_sector = logical >> 9;
if (atomic_read(&bbio->error) > bbio->max_errors)
bio->bi_status = BLK_STS_IOERR;
else
bio->bi_status = BLK_STS_OK;
btrfs_end_bbio(bbio, bio);
}
}
blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
int mirror_num)
{
struct btrfs_device *dev;
struct bio *first_bio = bio;
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
int dev_nr;
int total_devs;
struct btrfs_bio *bbio = NULL;
length = bio->bi_iter.bi_size;
map_length = length;
btrfs_bio_counter_inc_blocked(fs_info);
ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical,
&map_length, &bbio, mirror_num, 1);
if (ret) {
btrfs_bio_counter_dec(fs_info);
return errno_to_blk_status(ret);
}
total_devs = bbio->num_stripes;
bbio->orig_bio = first_bio;
bbio->private = first_bio->bi_private;
bbio->end_io = first_bio->bi_end_io;
bbio->fs_info = fs_info;
atomic_set(&bbio->stripes_pending, bbio->num_stripes);
if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) {
/* In this case, map_length has been set to the length of
a single stripe; not the whole write */
if (bio_op(bio) == REQ_OP_WRITE) {
ret = raid56_parity_write(fs_info, bio, bbio,
map_length);
} else {
ret = raid56_parity_recover(fs_info, bio, bbio,
map_length, mirror_num, 1);
}
btrfs_bio_counter_dec(fs_info);
return errno_to_blk_status(ret);
}
if (map_length < length) {
btrfs_crit(fs_info,
"mapping failed logical %llu bio len %llu len %llu",
logical, length, map_length);
BUG();
}
for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
dev = bbio->stripes[dev_nr].dev;
if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING,
&dev->dev_state) ||
(bio_op(first_bio) == REQ_OP_WRITE &&
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
bbio_error(bbio, first_bio, logical);
continue;
}
if (dev_nr < total_devs - 1)
bio = btrfs_bio_clone(first_bio);
else
bio = first_bio;
submit_stripe_bio(bbio, bio, bbio->stripes[dev_nr].physical, dev);
}
btrfs_bio_counter_dec(fs_info);
return BLK_STS_OK;
}
/*
* Find a device specified by @devid or @uuid in the list of @fs_devices, or
* return NULL.
*
* If devid and uuid are both specified, the match must be exact, otherwise
* only devid is used.
*
* If @seed is true, traverse through the seed devices.
*/
struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
u64 devid, u8 *uuid, u8 *fsid,
bool seed)
{
struct btrfs_device *device;
while (fs_devices) {
if (!fsid ||
!memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) {
list_for_each_entry(device, &fs_devices->devices,
dev_list) {
if (device->devid == devid &&
(!uuid || memcmp(device->uuid, uuid,
BTRFS_UUID_SIZE) == 0))
return device;
}
}
if (seed)
fs_devices = fs_devices->seed;
else
return NULL;
}
return NULL;
}
static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices,
u64 devid, u8 *dev_uuid)
{
struct btrfs_device *device;
device = btrfs_alloc_device(NULL, &devid, dev_uuid);
if (IS_ERR(device))
return device;
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
fs_devices->missing_devices++;
return device;
}
/**
* btrfs_alloc_device - allocate struct btrfs_device
* @fs_info: used only for generating a new devid, can be NULL if
* devid is provided (i.e. @devid != NULL).
* @devid: a pointer to devid for this device. If NULL a new devid
* is generated.
* @uuid: a pointer to UUID for this device. If NULL a new UUID
* is generated.
*
* Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
* on error. Returned struct is not linked onto any lists and must be
* destroyed with btrfs_free_device.
*/
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
const u64 *devid,
const u8 *uuid)
{
struct btrfs_device *dev;
u64 tmp;
if (WARN_ON(!devid && !fs_info))
return ERR_PTR(-EINVAL);
dev = __alloc_device();
if (IS_ERR(dev))
return dev;
if (devid)
tmp = *devid;
else {
int ret;
ret = find_next_devid(fs_info, &tmp);
if (ret) {
btrfs_free_device(dev);
return ERR_PTR(ret);
}
}
dev->devid = tmp;
if (uuid)
memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
else
generate_random_uuid(dev->uuid);
return dev;
}
static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
u64 devid, u8 *uuid, bool error)
{
if (error)
btrfs_err_rl(fs_info, "devid %llu uuid %pU is missing",
devid, uuid);
else
btrfs_warn_rl(fs_info, "devid %llu uuid %pU is missing",
devid, uuid);
}
static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
{
int index = btrfs_bg_flags_to_raid_index(type);
int ncopies = btrfs_raid_array[index].ncopies;
const int nparity = btrfs_raid_array[index].nparity;
int data_stripes;
if (nparity)
data_stripes = num_stripes - nparity;
else
data_stripes = num_stripes / ncopies;
return div_u64(chunk_len, data_stripes);
}
static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
struct btrfs_chunk *chunk)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
u64 logical;
u64 length;
u64 devid;
u8 uuid[BTRFS_UUID_SIZE];
int num_stripes;
int ret;
int i;
logical = key->offset;
length = btrfs_chunk_length(leaf, chunk);
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
/*
* Only need to verify chunk item if we're reading from sys chunk array,
* as chunk item in tree block is already verified by tree-checker.
*/
if (leaf->start == BTRFS_SUPER_INFO_OFFSET) {
ret = btrfs_check_chunk_valid(leaf, chunk, logical);
if (ret)
return ret;
}
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, logical, 1);
read_unlock(&map_tree->lock);
/* already mapped? */
if (em && em->start <= logical && em->start + em->len > logical) {
free_extent_map(em);
return 0;
} else if (em) {
free_extent_map(em);
}
em = alloc_extent_map();
if (!em)
return -ENOMEM;
map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
free_extent_map(em);
return -ENOMEM;
}
set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
em->map_lookup = map;
em->start = logical;
em->len = length;
em->orig_start = 0;
em->block_start = 0;
em->block_len = em->len;
map->num_stripes = num_stripes;
map->io_width = btrfs_chunk_io_width(leaf, chunk);
map->io_align = btrfs_chunk_io_align(leaf, chunk);
map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
map->type = btrfs_chunk_type(leaf, chunk);
map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
map->verified_stripes = 0;
em->orig_block_len = calc_stripe_length(map->type, em->len,
map->num_stripes);
for (i = 0; i < num_stripes; i++) {
map->stripes[i].physical =
btrfs_stripe_offset_nr(leaf, chunk, i);
devid = btrfs_stripe_devid_nr(leaf, chunk, i);
read_extent_buffer(leaf, uuid, (unsigned long)
btrfs_stripe_dev_uuid_nr(chunk, i),
BTRFS_UUID_SIZE);
map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices,
devid, uuid, NULL, true);
if (!map->stripes[i].dev &&
!btrfs_test_opt(fs_info, DEGRADED)) {
free_extent_map(em);
btrfs_report_missing_device(fs_info, devid, uuid, true);
return -ENOENT;
}
if (!map->stripes[i].dev) {
map->stripes[i].dev =
add_missing_dev(fs_info->fs_devices, devid,
uuid);
if (IS_ERR(map->stripes[i].dev)) {
free_extent_map(em);
btrfs_err(fs_info,
"failed to init missing dev %llu: %ld",
devid, PTR_ERR(map->stripes[i].dev));
return PTR_ERR(map->stripes[i].dev);
}
btrfs_report_missing_device(fs_info, devid, uuid, false);
}
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&(map->stripes[i].dev->dev_state));
}
write_lock(&map_tree->lock);
ret = add_extent_mapping(map_tree, em, 0);
write_unlock(&map_tree->lock);
if (ret < 0) {
btrfs_err(fs_info,
"failed to add chunk map, start=%llu len=%llu: %d",
em->start, em->len, ret);
}
free_extent_map(em);
return ret;
}
static void fill_device_from_item(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item,
struct btrfs_device *device)
{
unsigned long ptr;
device->devid = btrfs_device_id(leaf, dev_item);
device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
device->total_bytes = device->disk_total_bytes;
device->commit_total_bytes = device->disk_total_bytes;
device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
device->commit_bytes_used = device->bytes_used;
device->type = btrfs_device_type(leaf, dev_item);
device->io_align = btrfs_device_io_align(leaf, dev_item);
device->io_width = btrfs_device_io_width(leaf, dev_item);
device->sector_size = btrfs_device_sector_size(leaf, dev_item);
WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
ptr = btrfs_device_uuid(dev_item);
read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
}
static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info,
u8 *fsid)
{
struct btrfs_fs_devices *fs_devices;
int ret;
lockdep_assert_held(&uuid_mutex);
ASSERT(fsid);
fs_devices = fs_info->fs_devices->seed;
while (fs_devices) {
if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE))
return fs_devices;
fs_devices = fs_devices->seed;
}
fs_devices = find_fsid(fsid, NULL);
if (!fs_devices) {
if (!btrfs_test_opt(fs_info, DEGRADED))
return ERR_PTR(-ENOENT);
fs_devices = alloc_fs_devices(fsid, NULL);
if (IS_ERR(fs_devices))
return fs_devices;
fs_devices->seeding = true;
fs_devices->opened = 1;
return fs_devices;
}
fs_devices = clone_fs_devices(fs_devices);
if (IS_ERR(fs_devices))
return fs_devices;
ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
if (ret) {
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(ret);
goto out;
}
if (!fs_devices->seeding) {
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(-EINVAL);
goto out;
}
fs_devices->seed = fs_info->fs_devices->seed;
fs_info->fs_devices->seed = fs_devices;
out:
return fs_devices;
}
static int read_one_dev(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
u64 devid;
int ret;
u8 fs_uuid[BTRFS_FSID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
devid = btrfs_device_id(leaf, dev_item);
read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
BTRFS_FSID_SIZE);
if (memcmp(fs_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)) {
fs_devices = open_seed_devices(fs_info, fs_uuid);
if (IS_ERR(fs_devices))
return PTR_ERR(fs_devices);
}
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
fs_uuid, true);
if (!device) {
if (!btrfs_test_opt(fs_info, DEGRADED)) {
btrfs_report_missing_device(fs_info, devid,
dev_uuid, true);
return -ENOENT;
}
device = add_missing_dev(fs_devices, devid, dev_uuid);
if (IS_ERR(device)) {
btrfs_err(fs_info,
"failed to add missing dev %llu: %ld",
devid, PTR_ERR(device));
return PTR_ERR(device);
}
btrfs_report_missing_device(fs_info, devid, dev_uuid, false);
} else {
if (!device->bdev) {
if (!btrfs_test_opt(fs_info, DEGRADED)) {
btrfs_report_missing_device(fs_info,
devid, dev_uuid, true);
return -ENOENT;
}
btrfs_report_missing_device(fs_info, devid,
dev_uuid, false);
}
if (!device->bdev &&
!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
/*
* this happens when a device that was properly setup
* in the device info lists suddenly goes bad.
* device->bdev is NULL, and so we have to set
* device->missing to one here
*/
device->fs_devices->missing_devices++;
set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
}
/* Move the device to its own fs_devices */
if (device->fs_devices != fs_devices) {
ASSERT(test_bit(BTRFS_DEV_STATE_MISSING,
&device->dev_state));
list_move(&device->dev_list, &fs_devices->devices);
device->fs_devices->num_devices--;
fs_devices->num_devices++;
device->fs_devices->missing_devices--;
fs_devices->missing_devices++;
device->fs_devices = fs_devices;
}
}
if (device->fs_devices != fs_info->fs_devices) {
BUG_ON(test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state));
if (device->generation !=
btrfs_device_generation(leaf, dev_item))
return -EINVAL;
}
fill_device_from_item(leaf, dev_item, device);
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
device->fs_devices->total_rw_bytes += device->total_bytes;
atomic64_add(device->total_bytes - device->bytes_used,
&fs_info->free_chunk_space);
}
ret = 0;
return ret;
}
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct extent_buffer *sb;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *array_ptr;
unsigned long sb_array_offset;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur_offset;
u64 type;
struct btrfs_key key;
ASSERT(BTRFS_SUPER_INFO_SIZE <= fs_info->nodesize);
/*
* This will create extent buffer of nodesize, superblock size is
* fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will
* overallocate but we can keep it as-is, only the first page is used.
*/
sb = btrfs_find_create_tree_block(fs_info, BTRFS_SUPER_INFO_OFFSET);
if (IS_ERR(sb))
return PTR_ERR(sb);
set_extent_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
/*
* The sb extent buffer is artificial and just used to read the system array.
* set_extent_buffer_uptodate() call does not properly mark all it's
* pages up-to-date when the page is larger: extent does not cover the
* whole page and consequently check_page_uptodate does not find all
* the page's extents up-to-date (the hole beyond sb),
* write_extent_buffer then triggers a WARN_ON.
*
* Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
* but sb spans only this function. Add an explicit SetPageUptodate call
* to silence the warning eg. on PowerPC 64.
*/
if (PAGE_SIZE > BTRFS_SUPER_INFO_SIZE)
SetPageUptodate(sb->pages[0]);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy);
array_ptr = super_copy->sys_chunk_array;
sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
cur_offset = 0;
while (cur_offset < array_size) {
disk_key = (struct btrfs_disk_key *)array_ptr;
len = sizeof(*disk_key);
if (cur_offset + len > array_size)
goto out_short_read;
btrfs_disk_key_to_cpu(&key, disk_key);
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
if (key.type != BTRFS_CHUNK_ITEM_KEY) {
btrfs_err(fs_info,
"unexpected item type %u in sys_array at offset %u",
(u32)key.type, cur_offset);
ret = -EIO;
break;
}
chunk = (struct btrfs_chunk *)sb_array_offset;
/*
* At least one btrfs_chunk with one stripe must be present,
* exact stripe count check comes afterwards
*/
len = btrfs_chunk_item_size(1);
if (cur_offset + len > array_size)
goto out_short_read;
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
if (!num_stripes) {
btrfs_err(fs_info,
"invalid number of stripes %u in sys_array at offset %u",
num_stripes, cur_offset);
ret = -EIO;
break;
}
type = btrfs_chunk_type(sb, chunk);
if ((type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) {
btrfs_err(fs_info,
"invalid chunk type %llu in sys_array at offset %u",
type, cur_offset);
ret = -EIO;
break;
}
len = btrfs_chunk_item_size(num_stripes);
if (cur_offset + len > array_size)
goto out_short_read;
ret = read_one_chunk(&key, sb, chunk);
if (ret)
break;
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
}
clear_extent_buffer_uptodate(sb);
free_extent_buffer_stale(sb);
return ret;
out_short_read:
btrfs_err(fs_info, "sys_array too short to read %u bytes at offset %u",
len, cur_offset);
clear_extent_buffer_uptodate(sb);
free_extent_buffer_stale(sb);
return -EIO;
}
/*
* Check if all chunks in the fs are OK for read-write degraded mount
*
* If the @failing_dev is specified, it's accounted as missing.
*
* Return true if all chunks meet the minimal RW mount requirements.
* Return false if any chunk doesn't meet the minimal RW mount requirements.
*/
bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
struct btrfs_device *failing_dev)
{
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct extent_map *em;
u64 next_start = 0;
bool ret = true;
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, 0, (u64)-1);
read_unlock(&map_tree->lock);
/* No chunk at all? Return false anyway */
if (!em) {
ret = false;
goto out;
}
while (em) {
struct map_lookup *map;
int missing = 0;
int max_tolerated;
int i;
map = em->map_lookup;
max_tolerated =
btrfs_get_num_tolerated_disk_barrier_failures(
map->type);
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *dev = map->stripes[i].dev;
if (!dev || !dev->bdev ||
test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
dev->last_flush_error)
missing++;
else if (failing_dev && failing_dev == dev)
missing++;
}
if (missing > max_tolerated) {
if (!failing_dev)
btrfs_warn(fs_info,
"chunk %llu missing %d devices, max tolerance is %d for writable mount",
em->start, missing, max_tolerated);
free_extent_map(em);
ret = false;
goto out;
}
next_start = extent_map_end(em);
free_extent_map(em);
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, next_start,
(u64)(-1) - next_start);
read_unlock(&map_tree->lock);
}
out:
return ret;
}
static void readahead_tree_node_children(struct extent_buffer *node)
{
int i;
const int nr_items = btrfs_header_nritems(node);
for (i = 0; i < nr_items; i++) {
u64 start;
start = btrfs_node_blockptr(node, i);
readahead_tree_block(node->fs_info, start);
}
}
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
int ret;
int slot;
u64 total_dev = 0;
u64 last_ra_node = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* uuid_mutex is needed only if we are mounting a sprout FS
* otherwise we don't need it.
*/
mutex_lock(&uuid_mutex);
/*
* It is possible for mount and umount to race in such a way that
* we execute this code path, but open_fs_devices failed to clear
* total_rw_bytes. We certainly want it cleared before reading the
* device items, so clear it here.
*/
fs_info->fs_devices->total_rw_bytes = 0;
/*
* Read all device items, and then all the chunk items. All
* device items are found before any chunk item (their object id
* is smaller than the lowest possible object id for a chunk
* item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
*/
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto error;
while (1) {
struct extent_buffer *node;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
break;
}
/*
* The nodes on level 1 are not locked but we don't need to do
* that during mount time as nothing else can access the tree
*/
node = path->nodes[1];
if (node) {
if (last_ra_node != node->start) {
readahead_tree_node_children(node);
last_ra_node = node->start;
}
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.type == BTRFS_DEV_ITEM_KEY) {
struct btrfs_dev_item *dev_item;
dev_item = btrfs_item_ptr(leaf, slot,
struct btrfs_dev_item);
ret = read_one_dev(leaf, dev_item);
if (ret)
goto error;
total_dev++;
} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
struct btrfs_chunk *chunk;
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
mutex_lock(&fs_info->chunk_mutex);
ret = read_one_chunk(&found_key, leaf, chunk);
mutex_unlock(&fs_info->chunk_mutex);
if (ret)
goto error;
}
path->slots[0]++;
}
/*
* After loading chunk tree, we've got all device information,
* do another round of validation checks.
*/
if (total_dev != fs_info->fs_devices->total_devices) {
btrfs_err(fs_info,
"super_num_devices %llu mismatch with num_devices %llu found here",
btrfs_super_num_devices(fs_info->super_copy),
total_dev);
ret = -EINVAL;
goto error;
}
if (btrfs_super_total_bytes(fs_info->super_copy) <
fs_info->fs_devices->total_rw_bytes) {
btrfs_err(fs_info,
"super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu",
btrfs_super_total_bytes(fs_info->super_copy),
fs_info->fs_devices->total_rw_bytes);
ret = -EINVAL;
goto error;
}
ret = 0;
error:
mutex_unlock(&uuid_mutex);
btrfs_free_path(path);
return ret;
}
void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
while (fs_devices) {
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list)
device->fs_info = fs_info;
mutex_unlock(&fs_devices->device_list_mutex);
fs_devices = fs_devices->seed;
}
}
static u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
const struct btrfs_dev_stats_item *ptr,
int index)
{
u64 val;
read_extent_buffer(eb, &val,
offsetof(struct btrfs_dev_stats_item, values) +
((unsigned long)ptr) + (index * sizeof(u64)),
sizeof(val));
return val;
}
static void btrfs_set_dev_stats_value(struct extent_buffer *eb,
struct btrfs_dev_stats_item *ptr,
int index, u64 val)
{
write_extent_buffer(eb, &val,
offsetof(struct btrfs_dev_stats_item, values) +
((unsigned long)ptr) + (index * sizeof(u64)),
sizeof(val));
}
int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
{
struct btrfs_key key;
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct extent_buffer *eb;
int slot;
int ret = 0;
struct btrfs_device *device;
struct btrfs_path *path = NULL;
int i;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
int item_size;
struct btrfs_dev_stats_item *ptr;
key.objectid = BTRFS_DEV_STATS_OBJECTID;
key.type = BTRFS_PERSISTENT_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
if (ret) {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
btrfs_dev_stat_set(device, i, 0);
device->dev_stats_valid = 1;
btrfs_release_path(path);
continue;
}
slot = path->slots[0];
eb = path->nodes[0];
item_size = btrfs_item_size_nr(eb, slot);
ptr = btrfs_item_ptr(eb, slot,
struct btrfs_dev_stats_item);
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
if (item_size >= (1 + i) * sizeof(__le64))
btrfs_dev_stat_set(device, i,
btrfs_dev_stats_value(eb, ptr, i));
else
btrfs_dev_stat_set(device, i, 0);
}
device->dev_stats_valid = 1;
btrfs_dev_stat_print_on_load(device);
btrfs_release_path(path);
}
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}
static int update_dev_stat_item(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *eb;
struct btrfs_dev_stats_item *ptr;
int ret;
int i;
key.objectid = BTRFS_DEV_STATS_OBJECTID;
key.type = BTRFS_PERSISTENT_ITEM_KEY;
key.offset = device->devid;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
if (ret < 0) {
btrfs_warn_in_rcu(fs_info,
"error %d while searching for dev_stats item for device %s",
ret, rcu_str_deref(device->name));
goto out;
}
if (ret == 0 &&
btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
/* need to delete old one and insert a new one */
ret = btrfs_del_item(trans, dev_root, path);
if (ret != 0) {
btrfs_warn_in_rcu(fs_info,
"delete too small dev_stats item for device %s failed %d",
rcu_str_deref(device->name), ret);
goto out;
}
ret = 1;
}
if (ret == 1) {
/* need to insert a new item */
btrfs_release_path(path);
ret = btrfs_insert_empty_item(trans, dev_root, path,
&key, sizeof(*ptr));
if (ret < 0) {
btrfs_warn_in_rcu(fs_info,
"insert dev_stats item for device %s failed %d",
rcu_str_deref(device->name), ret);
goto out;
}
}
eb = path->nodes[0];
ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
btrfs_set_dev_stats_value(eb, ptr, i,
btrfs_dev_stat_read(device, i));
btrfs_mark_buffer_dirty(eb);
out:
btrfs_free_path(path);
return ret;
}
/*
* called from commit_transaction. Writes all changed device stats to disk.
*/
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
int stats_cnt;
int ret = 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
stats_cnt = atomic_read(&device->dev_stats_ccnt);
if (!device->dev_stats_valid || stats_cnt == 0)
continue;
/*
* There is a LOAD-LOAD control dependency between the value of
* dev_stats_ccnt and updating the on-disk values which requires
* reading the in-memory counters. Such control dependencies
* require explicit read memory barriers.
*
* This memory barriers pairs with smp_mb__before_atomic in
* btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full
* barrier implied by atomic_xchg in
* btrfs_dev_stats_read_and_reset
*/
smp_rmb();
ret = update_dev_stat_item(trans, device);
if (!ret)
atomic_sub(stats_cnt, &device->dev_stats_ccnt);
}
mutex_unlock(&fs_devices->device_list_mutex);
return ret;
}
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
{
btrfs_dev_stat_inc(dev, index);
btrfs_dev_stat_print_on_error(dev);
}
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
{
if (!dev->dev_stats_valid)
return;
btrfs_err_rl_in_rcu(dev->fs_info,
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
rcu_str_deref(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
}
static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
{
int i;
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
if (btrfs_dev_stat_read(dev, i) != 0)
break;
if (i == BTRFS_DEV_STAT_VALUES_MAX)
return; /* all values == 0, suppress message */
btrfs_info_in_rcu(dev->fs_info,
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
rcu_str_deref(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
}
int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_get_dev_stats *stats)
{
struct btrfs_device *dev;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
int i;
mutex_lock(&fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, stats->devid, NULL, NULL,
true);
mutex_unlock(&fs_devices->device_list_mutex);
if (!dev) {
btrfs_warn(fs_info, "get dev_stats failed, device not found");
return -ENODEV;
} else if (!dev->dev_stats_valid) {
btrfs_warn(fs_info, "get dev_stats failed, not yet valid");
return -ENODEV;
} else if (stats->flags & BTRFS_DEV_STATS_RESET) {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
if (stats->nr_items > i)
stats->values[i] =
btrfs_dev_stat_read_and_reset(dev, i);
else
btrfs_dev_stat_set(dev, i, 0);
}
btrfs_info(fs_info, "device stats zeroed by %s (%d)",
current->comm, task_pid_nr(current));
} else {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
if (stats->nr_items > i)
stats->values[i] = btrfs_dev_stat_read(dev, i);
}
if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
return 0;
}
/*
* Update the size and bytes used for each device where it changed. This is
* delayed since we would otherwise get errors while writing out the
* superblocks.
*
* Must be invoked during transaction commit.
*/
void btrfs_commit_device_sizes(struct btrfs_transaction *trans)
{
struct btrfs_device *curr, *next;
ASSERT(trans->state == TRANS_STATE_COMMIT_DOING);
if (list_empty(&trans->dev_update_list))
return;
/*
* We don't need the device_list_mutex here. This list is owned by the
* transaction and the transaction must complete before the device is
* released.
*/
mutex_lock(&trans->fs_info->chunk_mutex);
list_for_each_entry_safe(curr, next, &trans->dev_update_list,
post_commit_list) {
list_del_init(&curr->post_commit_list);
curr->commit_total_bytes = curr->disk_total_bytes;
curr->commit_bytes_used = curr->bytes_used;
}
mutex_unlock(&trans->fs_info->chunk_mutex);
}
void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
while (fs_devices) {
fs_devices->fs_info = fs_info;
fs_devices = fs_devices->seed;
}
}
void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
while (fs_devices) {
fs_devices->fs_info = NULL;
fs_devices = fs_devices->seed;
}
}
/*
* Multiplicity factor for simple profiles: DUP, RAID1-like and RAID10.
*/
int btrfs_bg_type_to_factor(u64 flags)
{
const int index = btrfs_bg_flags_to_raid_index(flags);
return btrfs_raid_array[index].ncopies;
}
static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
u64 chunk_offset, u64 devid,
u64 physical_offset, u64 physical_len)
{
struct extent_map_tree *em_tree = &fs_info->mapping_tree;
struct extent_map *em;
struct map_lookup *map;
struct btrfs_device *dev;
u64 stripe_len;
bool found = false;
int ret = 0;
int i;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_offset, 1);
read_unlock(&em_tree->lock);
if (!em) {
btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk",
physical_offset, devid);
ret = -EUCLEAN;
goto out;
}
map = em->map_lookup;
stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes);
if (physical_len != stripe_len) {
btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu",
physical_offset, devid, em->start, physical_len,
stripe_len);
ret = -EUCLEAN;
goto out;
}
for (i = 0; i < map->num_stripes; i++) {
if (map->stripes[i].dev->devid == devid &&
map->stripes[i].physical == physical_offset) {
found = true;
if (map->verified_stripes >= map->num_stripes) {
btrfs_err(fs_info,
"too many dev extents for chunk %llu found",
em->start);
ret = -EUCLEAN;
goto out;
}
map->verified_stripes++;
break;
}
}
if (!found) {
btrfs_err(fs_info,
"dev extent physical offset %llu devid %llu has no corresponding chunk",
physical_offset, devid);
ret = -EUCLEAN;
}
/* Make sure no dev extent is beyond device bondary */
dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
if (!dev) {
btrfs_err(fs_info, "failed to find devid %llu", devid);
ret = -EUCLEAN;
goto out;
}
/* It's possible this device is a dummy for seed device */
if (dev->disk_total_bytes == 0) {
dev = btrfs_find_device(fs_info->fs_devices->seed, devid, NULL,
NULL, false);
if (!dev) {
btrfs_err(fs_info, "failed to find seed devid %llu",
devid);
ret = -EUCLEAN;
goto out;
}
}
if (physical_offset + physical_len > dev->disk_total_bytes) {
btrfs_err(fs_info,
"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu",
devid, physical_offset, physical_len,
dev->disk_total_bytes);
ret = -EUCLEAN;
goto out;
}
out:
free_extent_map(em);
return ret;
}
static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info)
{
struct extent_map_tree *em_tree = &fs_info->mapping_tree;
struct extent_map *em;
struct rb_node *node;
int ret = 0;
read_lock(&em_tree->lock);
for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) {
em = rb_entry(node, struct extent_map, rb_node);
if (em->map_lookup->num_stripes !=
em->map_lookup->verified_stripes) {
btrfs_err(fs_info,
"chunk %llu has missing dev extent, have %d expect %d",
em->start, em->map_lookup->verified_stripes,
em->map_lookup->num_stripes);
ret = -EUCLEAN;
goto out;
}
}
out:
read_unlock(&em_tree->lock);
return ret;
}
/*
* Ensure that all dev extents are mapped to correct chunk, otherwise
* later chunk allocation/free would cause unexpected behavior.
*
* NOTE: This will iterate through the whole device tree, which should be of
* the same size level as the chunk tree. This slightly increases mount time.
*/
int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
{
struct btrfs_path *path;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_key key;
u64 prev_devid = 0;
u64 prev_dev_ext_end = 0;
int ret = 0;
key.objectid = 1;
key.type = BTRFS_DEV_EXTENT_KEY;
key.offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_item(root, path);
if (ret < 0)
goto out;
/* No dev extents at all? Not good */
if (ret > 0) {
ret = -EUCLEAN;
goto out;
}
}
while (1) {
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_dev_extent *dext;
int slot = path->slots[0];
u64 chunk_offset;
u64 physical_offset;
u64 physical_len;
u64 devid;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.type != BTRFS_DEV_EXTENT_KEY)
break;
devid = key.objectid;
physical_offset = key.offset;
dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
physical_len = btrfs_dev_extent_length(leaf, dext);
/* Check if this dev extent overlaps with the previous one */
if (devid == prev_devid && physical_offset < prev_dev_ext_end) {
btrfs_err(fs_info,
"dev extent devid %llu physical offset %llu overlap with previous dev extent end %llu",
devid, physical_offset, prev_dev_ext_end);
ret = -EUCLEAN;
goto out;
}
ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
physical_offset, physical_len);
if (ret < 0)
goto out;
prev_devid = devid;
prev_dev_ext_end = physical_offset + physical_len;
ret = btrfs_next_item(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
}
/* Ensure all chunks have corresponding dev extents */
ret = verify_chunk_dev_extent_mapping(fs_info);
out:
btrfs_free_path(path);
return ret;
}
/*
* Check whether the given block group or device is pinned by any inode being
* used as a swapfile.
*/
bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
{
struct btrfs_swapfile_pin *sp;
struct rb_node *node;
spin_lock(&fs_info->swapfile_pins_lock);
node = fs_info->swapfile_pins.rb_node;
while (node) {
sp = rb_entry(node, struct btrfs_swapfile_pin, node);
if (ptr < sp->ptr)
node = node->rb_left;
else if (ptr > sp->ptr)
node = node->rb_right;
else
break;
}
spin_unlock(&fs_info->swapfile_pins_lock);
return node != NULL;
}
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