linux/fs/btrfs/ioctl.c
Josef Bacik 9ed74f2dba Btrfs: proper -ENOSPC handling
At the start of a transaction we do a btrfs_reserve_metadata_space() and
specify how many items we plan on modifying.  Then once we've done our
modifications and such, just call btrfs_unreserve_metadata_space() for
the same number of items we reserved.

For keeping track of metadata needed for data I've had to add an extent_io op
for when we merge extents.  This lets us track space properly when we are doing
sequential writes, so we don't end up reserving way more metadata space than
what we need.

The only place where the metadata space accounting is not done is in the
relocation code.  This is because Yan is going to be reworking that code in the
near future, so running btrfs-vol -b could still possibly result in a ENOSPC
related panic.  This patch also turns off the metadata_ratio stuff in order to
allow users to more efficiently use their disk space.

This patch makes it so we track how much metadata we need for an inode's
delayed allocation extents by tracking how many extents are currently
waiting for allocation.  It introduces two new callbacks for the
extent_io tree's, merge_extent_hook and split_extent_hook.  These help
us keep track of when we merge delalloc extents together and split them
up.  Reservations are handled prior to any actually dirty'ing occurs,
and then we unreserve after we dirty.

btrfs_unreserve_metadata_for_delalloc() will make the appropriate
unreservations as needed based on the number of reservations we
currently have and the number of extents we currently have.  Doing the
reservation outside of doing any of the actual dirty'ing lets us do
things like filemap_flush() the inode to try and force delalloc to
happen, or as a last resort actually start allocation on all delalloc
inodes in the fs.  This has survived dbench, fs_mark and an fsx torture
test.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-28 16:29:42 -04:00

1338 lines
32 KiB
C

/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mount.h>
#include <linux/mpage.h>
#include <linux/namei.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/vmalloc.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "volumes.h"
#include "locking.h"
/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
{
if (S_ISDIR(mode))
return flags;
else if (S_ISREG(mode))
return flags & ~FS_DIRSYNC_FL;
else
return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
}
/*
* Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
*/
static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
{
unsigned int iflags = 0;
if (flags & BTRFS_INODE_SYNC)
iflags |= FS_SYNC_FL;
if (flags & BTRFS_INODE_IMMUTABLE)
iflags |= FS_IMMUTABLE_FL;
if (flags & BTRFS_INODE_APPEND)
iflags |= FS_APPEND_FL;
if (flags & BTRFS_INODE_NODUMP)
iflags |= FS_NODUMP_FL;
if (flags & BTRFS_INODE_NOATIME)
iflags |= FS_NOATIME_FL;
if (flags & BTRFS_INODE_DIRSYNC)
iflags |= FS_DIRSYNC_FL;
return iflags;
}
/*
* Update inode->i_flags based on the btrfs internal flags.
*/
void btrfs_update_iflags(struct inode *inode)
{
struct btrfs_inode *ip = BTRFS_I(inode);
inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
if (ip->flags & BTRFS_INODE_SYNC)
inode->i_flags |= S_SYNC;
if (ip->flags & BTRFS_INODE_IMMUTABLE)
inode->i_flags |= S_IMMUTABLE;
if (ip->flags & BTRFS_INODE_APPEND)
inode->i_flags |= S_APPEND;
if (ip->flags & BTRFS_INODE_NOATIME)
inode->i_flags |= S_NOATIME;
if (ip->flags & BTRFS_INODE_DIRSYNC)
inode->i_flags |= S_DIRSYNC;
}
/*
* Inherit flags from the parent inode.
*
* Unlike extN we don't have any flags we don't want to inherit currently.
*/
void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
{
unsigned int flags;
if (!dir)
return;
flags = BTRFS_I(dir)->flags;
if (S_ISREG(inode->i_mode))
flags &= ~BTRFS_INODE_DIRSYNC;
else if (!S_ISDIR(inode->i_mode))
flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
BTRFS_I(inode)->flags = flags;
btrfs_update_iflags(inode);
}
static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
{
struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
if (copy_to_user(arg, &flags, sizeof(flags)))
return -EFAULT;
return 0;
}
static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct btrfs_inode *ip = BTRFS_I(inode);
struct btrfs_root *root = ip->root;
struct btrfs_trans_handle *trans;
unsigned int flags, oldflags;
int ret;
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
FS_NOATIME_FL | FS_NODUMP_FL | \
FS_SYNC_FL | FS_DIRSYNC_FL))
return -EOPNOTSUPP;
if (!is_owner_or_cap(inode))
return -EACCES;
mutex_lock(&inode->i_mutex);
flags = btrfs_mask_flags(inode->i_mode, flags);
oldflags = btrfs_flags_to_ioctl(ip->flags);
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
ret = -EPERM;
goto out_unlock;
}
}
ret = mnt_want_write(file->f_path.mnt);
if (ret)
goto out_unlock;
if (flags & FS_SYNC_FL)
ip->flags |= BTRFS_INODE_SYNC;
else
ip->flags &= ~BTRFS_INODE_SYNC;
if (flags & FS_IMMUTABLE_FL)
ip->flags |= BTRFS_INODE_IMMUTABLE;
else
ip->flags &= ~BTRFS_INODE_IMMUTABLE;
if (flags & FS_APPEND_FL)
ip->flags |= BTRFS_INODE_APPEND;
else
ip->flags &= ~BTRFS_INODE_APPEND;
if (flags & FS_NODUMP_FL)
ip->flags |= BTRFS_INODE_NODUMP;
else
ip->flags &= ~BTRFS_INODE_NODUMP;
if (flags & FS_NOATIME_FL)
ip->flags |= BTRFS_INODE_NOATIME;
else
ip->flags &= ~BTRFS_INODE_NOATIME;
if (flags & FS_DIRSYNC_FL)
ip->flags |= BTRFS_INODE_DIRSYNC;
else
ip->flags &= ~BTRFS_INODE_DIRSYNC;
trans = btrfs_join_transaction(root, 1);
BUG_ON(!trans);
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
btrfs_update_iflags(inode);
inode->i_ctime = CURRENT_TIME;
btrfs_end_transaction(trans, root);
mnt_drop_write(file->f_path.mnt);
out_unlock:
mutex_unlock(&inode->i_mutex);
return 0;
}
static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
return put_user(inode->i_generation, arg);
}
static noinline int create_subvol(struct btrfs_root *root,
struct dentry *dentry,
char *name, int namelen)
{
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *new_root;
struct inode *dir = dentry->d_parent->d_inode;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
unsigned long nr = 1;
/*
* 1 - inode item
* 2 - refs
* 1 - root item
* 2 - dir items
*/
ret = btrfs_reserve_metadata_space(root, 6);
if (ret)
return ret;
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
0, &objectid);
if (ret)
goto fail;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
0, objectid, NULL, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto fail;
}
memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(leaf, objectid);
write_extent_buffer(leaf, root->fs_info->fsid,
(unsigned long)btrfs_header_fsid(leaf),
BTRFS_FSID_SIZE);
write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
(unsigned long)btrfs_header_chunk_tree_uuid(leaf),
BTRFS_UUID_SIZE);
btrfs_mark_buffer_dirty(leaf);
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
inode_item->nbytes = cpu_to_le64(root->leafsize);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_bytenr(&root_item, leaf->start);
btrfs_set_root_generation(&root_item, trans->transid);
btrfs_set_root_level(&root_item, 0);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, 0);
btrfs_set_root_last_snapshot(&root_item, 0);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
btrfs_tree_unlock(leaf);
free_extent_buffer(leaf);
leaf = NULL;
btrfs_set_root_dirid(&root_item, new_dirid);
key.objectid = objectid;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
&root_item);
if (ret)
goto fail;
key.offset = (u64)-1;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
BUG_ON(IS_ERR(new_root));
btrfs_record_root_in_trans(trans, new_root);
ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
BTRFS_I(dir)->block_group);
/*
* insert the directory item
*/
ret = btrfs_set_inode_index(dir, &index);
BUG_ON(ret);
ret = btrfs_insert_dir_item(trans, root,
name, namelen, dir->i_ino, &key,
BTRFS_FT_DIR, index);
if (ret)
goto fail;
btrfs_i_size_write(dir, dir->i_size + namelen * 2);
ret = btrfs_update_inode(trans, root, dir);
BUG_ON(ret);
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir->i_ino, index, name, namelen);
BUG_ON(ret);
d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
fail:
nr = trans->blocks_used;
err = btrfs_commit_transaction(trans, root);
if (err && !ret)
ret = err;
btrfs_unreserve_metadata_space(root, 6);
btrfs_btree_balance_dirty(root, nr);
return ret;
}
static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
char *name, int namelen)
{
struct btrfs_pending_snapshot *pending_snapshot;
struct btrfs_trans_handle *trans;
int ret = 0;
int err;
unsigned long nr = 0;
if (!root->ref_cows)
return -EINVAL;
/*
* 1 - inode item
* 2 - refs
* 1 - root item
* 2 - dir items
*/
ret = btrfs_reserve_metadata_space(root, 6);
if (ret)
goto fail_unlock;
pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
if (!pending_snapshot) {
ret = -ENOMEM;
btrfs_unreserve_metadata_space(root, 6);
goto fail_unlock;
}
pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
if (!pending_snapshot->name) {
ret = -ENOMEM;
kfree(pending_snapshot);
btrfs_unreserve_metadata_space(root, 6);
goto fail_unlock;
}
memcpy(pending_snapshot->name, name, namelen);
pending_snapshot->name[namelen] = '\0';
pending_snapshot->dentry = dentry;
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
pending_snapshot->root = root;
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
err = btrfs_commit_transaction(trans, root);
fail_unlock:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
/* copy of may_create in fs/namei.c() */
static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
{
if (child->d_inode)
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
return inode_permission(dir, MAY_WRITE | MAY_EXEC);
}
/*
* Create a new subvolume below @parent. This is largely modeled after
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(struct path *parent,
char *name, int namelen,
struct btrfs_root *snap_src)
{
struct inode *dir = parent->dentry->d_inode;
struct dentry *dentry;
int error;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent->dentry, namelen);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_unlock;
error = -EEXIST;
if (dentry->d_inode)
goto out_dput;
error = mnt_want_write(parent->mnt);
if (error)
goto out_dput;
error = btrfs_may_create(dir, dentry);
if (error)
goto out_drop_write;
down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
goto out_up_read;
if (snap_src) {
error = create_snapshot(snap_src, dentry,
name, namelen);
} else {
error = create_subvol(BTRFS_I(dir)->root, dentry,
name, namelen);
}
if (!error)
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
out_drop_write:
mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&dir->i_mutex);
return error;
}
static int btrfs_defrag_file(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct page *page;
unsigned long last_index;
unsigned long ra_pages = root->fs_info->bdi.ra_pages;
unsigned long total_read = 0;
u64 page_start;
u64 page_end;
unsigned long i;
int ret;
ret = btrfs_check_data_free_space(root, inode, inode->i_size);
if (ret)
return -ENOSPC;
mutex_lock(&inode->i_mutex);
last_index = inode->i_size >> PAGE_CACHE_SHIFT;
for (i = 0; i <= last_index; i++) {
if (total_read % ra_pages == 0) {
btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
min(last_index, i + ra_pages - 1));
}
total_read++;
again:
page = grab_cache_page(inode->i_mapping, i);
if (!page)
goto out_unlock;
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
goto out_unlock;
}
}
wait_on_page_writeback(page);
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
set_page_extent_mapped(page);
/*
* this makes sure page_mkwrite is called on the
* page if it is dirtied again later
*/
clear_page_dirty_for_io(page);
btrfs_set_extent_delalloc(inode, page_start, page_end);
set_page_dirty(page);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
}
out_unlock:
mutex_unlock(&inode->i_mutex);
return 0;
}
static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
void __user *arg)
{
u64 new_size;
u64 old_size;
u64 devid = 1;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
struct btrfs_device *device = NULL;
char *sizestr;
char *devstr = NULL;
int ret = 0;
int namelen;
int mod = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
mutex_lock(&root->fs_info->volume_mutex);
sizestr = vol_args->name;
devstr = strchr(sizestr, ':');
if (devstr) {
char *end;
sizestr = devstr + 1;
*devstr = '\0';
devstr = vol_args->name;
devid = simple_strtoull(devstr, &end, 10);
printk(KERN_INFO "resizing devid %llu\n",
(unsigned long long)devid);
}
device = btrfs_find_device(root, devid, NULL, NULL);
if (!device) {
printk(KERN_INFO "resizer unable to find device %llu\n",
(unsigned long long)devid);
ret = -EINVAL;
goto out_unlock;
}
if (!strcmp(sizestr, "max"))
new_size = device->bdev->bd_inode->i_size;
else {
if (sizestr[0] == '-') {
mod = -1;
sizestr++;
} else if (sizestr[0] == '+') {
mod = 1;
sizestr++;
}
new_size = btrfs_parse_size(sizestr);
if (new_size == 0) {
ret = -EINVAL;
goto out_unlock;
}
}
old_size = device->total_bytes;
if (mod < 0) {
if (new_size > old_size) {
ret = -EINVAL;
goto out_unlock;
}
new_size = old_size - new_size;
} else if (mod > 0) {
new_size = old_size + new_size;
}
if (new_size < 256 * 1024 * 1024) {
ret = -EINVAL;
goto out_unlock;
}
if (new_size > device->bdev->bd_inode->i_size) {
ret = -EFBIG;
goto out_unlock;
}
do_div(new_size, root->sectorsize);
new_size *= root->sectorsize;
printk(KERN_INFO "new size for %s is %llu\n",
device->name, (unsigned long long)new_size);
if (new_size > old_size) {
trans = btrfs_start_transaction(root, 1);
ret = btrfs_grow_device(trans, device, new_size);
btrfs_commit_transaction(trans, root);
} else {
ret = btrfs_shrink_device(device, new_size);
}
out_unlock:
mutex_unlock(&root->fs_info->volume_mutex);
kfree(vol_args);
return ret;
}
static noinline int btrfs_ioctl_snap_create(struct file *file,
void __user *arg, int subvol)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct btrfs_ioctl_vol_args *vol_args;
struct file *src_file;
int namelen;
int ret = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
if (strchr(vol_args->name, '/')) {
ret = -EINVAL;
goto out;
}
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
NULL);
} else {
struct inode *src_inode;
src_file = fget(vol_args->fd);
if (!src_file) {
ret = -EINVAL;
goto out;
}
src_inode = src_file->f_path.dentry->d_inode;
if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
printk(KERN_INFO "btrfs: Snapshot src from "
"another FS\n");
ret = -EINVAL;
fput(src_file);
goto out;
}
ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
BTRFS_I(src_inode)->root);
fput(src_file);
}
out:
kfree(vol_args);
return ret;
}
/*
* helper to check if the subvolume references other subvolumes
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_path *path;
struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
&key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = 0;
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid == root->root_key.objectid &&
key.type == BTRFS_ROOT_REF_KEY)
ret = -ENOTEMPTY;
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_snap_destroy(struct file *file,
void __user *arg)
{
struct dentry *parent = fdentry(file);
struct dentry *dentry;
struct inode *dir = parent->d_inode;
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *dest = NULL;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
int namelen;
int ret;
int err = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
if (strchr(vol_args->name, '/') ||
strncmp(vol_args->name, "..", namelen) == 0) {
err = -EINVAL;
goto out;
}
err = mnt_want_write(file->f_path.mnt);
if (err)
goto out;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(vol_args->name, parent, namelen);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock_dir;
}
if (!dentry->d_inode) {
err = -ENOENT;
goto out_dput;
}
inode = dentry->d_inode;
if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
err = -EINVAL;
goto out_dput;
}
dest = BTRFS_I(inode)->root;
mutex_lock(&inode->i_mutex);
err = d_invalidate(dentry);
if (err)
goto out_unlock;
down_write(&root->fs_info->subvol_sem);
err = may_destroy_subvol(dest);
if (err)
goto out_up_write;
trans = btrfs_start_transaction(root, 1);
ret = btrfs_unlink_subvol(trans, root, dir,
dest->root_key.objectid,
dentry->d_name.name,
dentry->d_name.len);
BUG_ON(ret);
btrfs_record_root_in_trans(trans, dest);
memset(&dest->root_item.drop_progress, 0,
sizeof(dest->root_item.drop_progress));
dest->root_item.drop_level = 0;
btrfs_set_root_refs(&dest->root_item, 0);
ret = btrfs_insert_orphan_item(trans,
root->fs_info->tree_root,
dest->root_key.objectid);
BUG_ON(ret);
ret = btrfs_commit_transaction(trans, root);
BUG_ON(ret);
inode->i_flags |= S_DEAD;
out_up_write:
up_write(&root->fs_info->subvol_sem);
out_unlock:
mutex_unlock(&inode->i_mutex);
if (!err) {
btrfs_invalidate_inodes(dest);
d_delete(dentry);
}
out_dput:
dput(dentry);
out_unlock_dir:
mutex_unlock(&dir->i_mutex);
mnt_drop_write(file->f_path.mnt);
out:
kfree(vol_args);
return err;
}
static int btrfs_ioctl_defrag(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
btrfs_defrag_root(root, 0);
btrfs_defrag_root(root->fs_info->extent_root, 0);
break;
case S_IFREG:
if (!(file->f_mode & FMODE_WRITE)) {
ret = -EINVAL;
goto out;
}
btrfs_defrag_file(file);
break;
}
out:
mnt_drop_write(file->f_path.mnt);
return ret;
}
static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_init_new_device(root, vol_args->name);
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_rm_device(root, vol_args->name);
kfree(vol_args);
return ret;
}
static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct file *src_file;
struct inode *src;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct extent_buffer *leaf;
char *buf;
struct btrfs_key key;
u32 nritems;
int slot;
int ret;
u64 len = olen;
u64 bs = root->fs_info->sb->s_blocksize;
u64 hint_byte;
/*
* TODO:
* - split compressed inline extents. annoying: we need to
* decompress into destination's address_space (the file offset
* may change, so source mapping won't do), then recompress (or
* otherwise reinsert) a subrange.
* - allow ranges within the same file to be cloned (provided
* they don't overlap)?
*/
/* the destination must be opened for writing */
if (!(file->f_mode & FMODE_WRITE))
return -EINVAL;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
src_file = fget(srcfd);
if (!src_file) {
ret = -EBADF;
goto out_drop_write;
}
src = src_file->f_dentry->d_inode;
ret = -EINVAL;
if (src == inode)
goto out_fput;
ret = -EISDIR;
if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
goto out_fput;
ret = -EXDEV;
if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
goto out_fput;
ret = -ENOMEM;
buf = vmalloc(btrfs_level_size(root, 0));
if (!buf)
goto out_fput;
path = btrfs_alloc_path();
if (!path) {
vfree(buf);
goto out_fput;
}
path->reada = 2;
if (inode < src) {
mutex_lock(&inode->i_mutex);
mutex_lock(&src->i_mutex);
} else {
mutex_lock(&src->i_mutex);
mutex_lock(&inode->i_mutex);
}
/* determine range to clone */
ret = -EINVAL;
if (off >= src->i_size || off + len > src->i_size)
goto out_unlock;
if (len == 0)
olen = len = src->i_size - off;
/* if we extend to eof, continue to block boundary */
if (off + len == src->i_size)
len = ((src->i_size + bs-1) & ~(bs-1))
- off;
/* verify the end result is block aligned */
if ((off & (bs-1)) ||
((off + len) & (bs-1)))
goto out_unlock;
/* do any pending delalloc/csum calc on src, one way or
another, and lock file content */
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
break;
unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
if (ordered)
btrfs_put_ordered_extent(ordered);
btrfs_wait_ordered_range(src, off, off+len);
}
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
/* punch hole in destination first */
btrfs_drop_extents(trans, root, inode, off, off + len,
off + len, 0, &hint_byte, 1);
/* clone data */
key.objectid = src->i_ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
while (1) {
/*
* note the key will change type as we walk through the
* tree.
*/
ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0)
break;
nritems = btrfs_header_nritems(path->nodes[0]);
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
key.objectid != src->i_ino)
break;
if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
struct btrfs_file_extent_item *extent;
int type;
u32 size;
struct btrfs_key new_key;
u64 disko = 0, diskl = 0;
u64 datao = 0, datal = 0;
u8 comp;
size = btrfs_item_size_nr(leaf, slot);
read_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
comp = btrfs_file_extent_compression(leaf, extent);
type = btrfs_file_extent_type(leaf, extent);
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
disko = btrfs_file_extent_disk_bytenr(leaf,
extent);
diskl = btrfs_file_extent_disk_num_bytes(leaf,
extent);
datao = btrfs_file_extent_offset(leaf, extent);
datal = btrfs_file_extent_num_bytes(leaf,
extent);
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
/* take upper bound, may be compressed */
datal = btrfs_file_extent_ram_bytes(leaf,
extent);
}
btrfs_release_path(root, path);
if (key.offset + datal < off ||
key.offset >= off+len)
goto next;
memcpy(&new_key, &key, sizeof(new_key));
new_key.objectid = inode->i_ino;
new_key.offset = key.offset + destoff - off;
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
if (ret)
goto out;
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
if (off > key.offset) {
datao += off - key.offset;
datal -= off - key.offset;
}
if (key.offset + datao + datal > off + len)
datal = off + len - key.offset - datao;
/* disko == 0 means it's a hole */
if (!disko)
datao = 0;
btrfs_set_file_extent_offset(leaf, extent,
datao);
btrfs_set_file_extent_num_bytes(leaf, extent,
datal);
if (disko) {
inode_add_bytes(inode, datal);
ret = btrfs_inc_extent_ref(trans, root,
disko, diskl, 0,
root->root_key.objectid,
inode->i_ino,
new_key.offset - datao);
BUG_ON(ret);
}
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
u64 skip = 0;
u64 trim = 0;
if (off > key.offset) {
skip = off - key.offset;
new_key.offset += skip;
}
if (key.offset + datal > off+len)
trim = key.offset + datal - (off+len);
if (comp && (skip || trim)) {
ret = -EINVAL;
goto out;
}
size -= skip + trim;
datal -= skip + trim;
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
if (ret)
goto out;
if (skip) {
u32 start =
btrfs_file_extent_calc_inline_size(0);
memmove(buf+start, buf+start+skip,
datal);
}
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
inode_add_bytes(inode, datal);
}
btrfs_mark_buffer_dirty(leaf);
}
next:
btrfs_release_path(root, path);
key.offset++;
}
ret = 0;
out:
btrfs_release_path(root, path);
if (ret == 0) {
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
if (destoff + olen > inode->i_size)
btrfs_i_size_write(inode, destoff + olen);
BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans, root);
unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
if (ret)
vmtruncate(inode, 0);
out_unlock:
mutex_unlock(&src->i_mutex);
mutex_unlock(&inode->i_mutex);
vfree(buf);
btrfs_free_path(path);
out_fput:
fput(src_file);
out_drop_write:
mnt_drop_write(file->f_path.mnt);
return ret;
}
static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
{
struct btrfs_ioctl_clone_range_args args;
if (copy_from_user(&args, argp, sizeof(args)))
return -EFAULT;
return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
args.src_length, args.dest_offset);
}
/*
* there are many ways the trans_start and trans_end ioctls can lead
* to deadlocks. They should only be used by applications that
* basically own the machine, and have a very in depth understanding
* of all the possible deadlocks and enospc problems.
*/
static long btrfs_ioctl_trans_start(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (file->private_data) {
ret = -EINPROGRESS;
goto out;
}
ret = mnt_want_write(file->f_path.mnt);
if (ret)
goto out;
mutex_lock(&root->fs_info->trans_mutex);
root->fs_info->open_ioctl_trans++;
mutex_unlock(&root->fs_info->trans_mutex);
trans = btrfs_start_ioctl_transaction(root, 0);
if (trans)
file->private_data = trans;
else
ret = -ENOMEM;
/*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
out:
return ret;
}
/*
* there are many ways the trans_start and trans_end ioctls can lead
* to deadlocks. They should only be used by applications that
* basically own the machine, and have a very in depth understanding
* of all the possible deadlocks and enospc problems.
*/
long btrfs_ioctl_trans_end(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
trans = file->private_data;
if (!trans) {
ret = -EINVAL;
goto out;
}
btrfs_end_transaction(trans, root);
file->private_data = NULL;
mutex_lock(&root->fs_info->trans_mutex);
root->fs_info->open_ioctl_trans--;
mutex_unlock(&root->fs_info->trans_mutex);
mnt_drop_write(file->f_path.mnt);
out:
return ret;
}
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
void __user *argp = (void __user *)arg;
switch (cmd) {
case FS_IOC_GETFLAGS:
return btrfs_ioctl_getflags(file, argp);
case FS_IOC_SETFLAGS:
return btrfs_ioctl_setflags(file, argp);
case FS_IOC_GETVERSION:
return btrfs_ioctl_getversion(file, argp);
case BTRFS_IOC_SNAP_CREATE:
return btrfs_ioctl_snap_create(file, argp, 0);
case BTRFS_IOC_SUBVOL_CREATE:
return btrfs_ioctl_snap_create(file, argp, 1);
case BTRFS_IOC_SNAP_DESTROY:
return btrfs_ioctl_snap_destroy(file, argp);
case BTRFS_IOC_DEFRAG:
return btrfs_ioctl_defrag(file);
case BTRFS_IOC_RESIZE:
return btrfs_ioctl_resize(root, argp);
case BTRFS_IOC_ADD_DEV:
return btrfs_ioctl_add_dev(root, argp);
case BTRFS_IOC_RM_DEV:
return btrfs_ioctl_rm_dev(root, argp);
case BTRFS_IOC_BALANCE:
return btrfs_balance(root->fs_info->dev_root);
case BTRFS_IOC_CLONE:
return btrfs_ioctl_clone(file, arg, 0, 0, 0);
case BTRFS_IOC_CLONE_RANGE:
return btrfs_ioctl_clone_range(file, argp);
case BTRFS_IOC_TRANS_START:
return btrfs_ioctl_trans_start(file);
case BTRFS_IOC_TRANS_END:
return btrfs_ioctl_trans_end(file);
case BTRFS_IOC_SYNC:
btrfs_sync_fs(file->f_dentry->d_sb, 1);
return 0;
}
return -ENOTTY;
}