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linux/drivers/md/raid1.c
David Jeffery c91114c2b8 md/raid1: release pending accounting for an I/O only after write-behind is also finished 
When using RAID1 and write-behind, md can deadlock when errors occur. With
write-behind, r1bio structs can be accounted by raid1 as queued but not
counted as pending. The pending count is dropped when the original bio is
returned complete but write-behind for the r1bio may still be active.

This breaks the accounting used in some conditions to know when the raid1
md device has reached an idle state. It can result in calls to
freeze_array deadlocking. freeze_array will never complete from a negative
"unqueued" value being calculated due to a queued count larger than the
pending count.

To properly account for write-behind, move the call to allow_barrier from
call_bio_endio to raid_end_bio_io. When using write-behind, md can call
call_bio_endio before all write-behind I/O is complete. Using
raid_end_bio_io for the point to call allow_barrier will release the
pending count at a point where all I/O for an r1bio, even write-behind, is
done.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2020-05-13 11:22:31 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* raid1.c : Multiple Devices driver for Linux
*
* Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
*
* Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
*
* RAID-1 management functions.
*
* Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
*
* Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
* Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
*
* Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
* bitmapped intelligence in resync:
*
* - bitmap marked during normal i/o
* - bitmap used to skip nondirty blocks during sync
*
* Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
* - persistent bitmap code
*/
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
#include <linux/interval_tree_generic.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid1.h"
#include "md-bitmap.h"
#define UNSUPPORTED_MDDEV_FLAGS \
((1L << MD_HAS_JOURNAL) | \
(1L << MD_JOURNAL_CLEAN) | \
(1L << MD_HAS_PPL) | \
(1L << MD_HAS_MULTIPLE_PPLS))
static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
#define raid1_log(md, fmt, args...) \
do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
#include "raid1-10.c"
#define START(node) ((node)->start)
#define LAST(node) ((node)->last)
INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
START, LAST, static inline, raid1_rb);
static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
struct serial_info *si, int idx)
{
unsigned long flags;
int ret = 0;
sector_t lo = r1_bio->sector;
sector_t hi = lo + r1_bio->sectors;
struct serial_in_rdev *serial = &rdev->serial[idx];
spin_lock_irqsave(&serial->serial_lock, flags);
/* collision happened */
if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
ret = -EBUSY;
else {
si->start = lo;
si->last = hi;
raid1_rb_insert(si, &serial->serial_rb);
}
spin_unlock_irqrestore(&serial->serial_lock, flags);
return ret;
}
static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
{
struct mddev *mddev = rdev->mddev;
struct serial_info *si;
int idx = sector_to_idx(r1_bio->sector);
struct serial_in_rdev *serial = &rdev->serial[idx];
if (WARN_ON(!mddev->serial_info_pool))
return;
si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
wait_event(serial->serial_io_wait,
check_and_add_serial(rdev, r1_bio, si, idx) == 0);
}
static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
{
struct serial_info *si;
unsigned long flags;
int found = 0;
struct mddev *mddev = rdev->mddev;
int idx = sector_to_idx(lo);
struct serial_in_rdev *serial = &rdev->serial[idx];
spin_lock_irqsave(&serial->serial_lock, flags);
for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
si; si = raid1_rb_iter_next(si, lo, hi)) {
if (si->start == lo && si->last == hi) {
raid1_rb_remove(si, &serial->serial_rb);
mempool_free(si, mddev->serial_info_pool);
found = 1;
break;
}
}
if (!found)
WARN(1, "The write IO is not recorded for serialization\n");
spin_unlock_irqrestore(&serial->serial_lock, flags);
wake_up(&serial->serial_io_wait);
}
/*
* for resync bio, r1bio pointer can be retrieved from the per-bio
* 'struct resync_pages'.
*/
static inline struct r1bio *get_resync_r1bio(struct bio *bio)
{
return get_resync_pages(bio)->raid_bio;
}
static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
{
struct pool_info *pi = data;
int size = offsetof(struct r1bio, bios[pi->raid_disks]);
/* allocate a r1bio with room for raid_disks entries in the bios array */
return kzalloc(size, gfp_flags);
}
#define RESYNC_DEPTH 32
#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
{
struct pool_info *pi = data;
struct r1bio *r1_bio;
struct bio *bio;
int need_pages;
int j;
struct resync_pages *rps;
r1_bio = r1bio_pool_alloc(gfp_flags, pi);
if (!r1_bio)
return NULL;
rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
gfp_flags);
if (!rps)
goto out_free_r1bio;
/*
* Allocate bios : 1 for reading, n-1 for writing
*/
for (j = pi->raid_disks ; j-- ; ) {
bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
if (!bio)
goto out_free_bio;
r1_bio->bios[j] = bio;
}
/*
* Allocate RESYNC_PAGES data pages and attach them to
* the first bio.
* If this is a user-requested check/repair, allocate
* RESYNC_PAGES for each bio.
*/
if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
need_pages = pi->raid_disks;
else
need_pages = 1;
for (j = 0; j < pi->raid_disks; j++) {
struct resync_pages *rp = &rps[j];
bio = r1_bio->bios[j];
if (j < need_pages) {
if (resync_alloc_pages(rp, gfp_flags))
goto out_free_pages;
} else {
memcpy(rp, &rps[0], sizeof(*rp));
resync_get_all_pages(rp);
}
rp->raid_bio = r1_bio;
bio->bi_private = rp;
}
r1_bio->master_bio = NULL;
return r1_bio;
out_free_pages:
while (--j >= 0)
resync_free_pages(&rps[j]);
out_free_bio:
while (++j < pi->raid_disks)
bio_put(r1_bio->bios[j]);
kfree(rps);
out_free_r1bio:
rbio_pool_free(r1_bio, data);
return NULL;
}
static void r1buf_pool_free(void *__r1_bio, void *data)
{
struct pool_info *pi = data;
int i;
struct r1bio *r1bio = __r1_bio;
struct resync_pages *rp = NULL;
for (i = pi->raid_disks; i--; ) {
rp = get_resync_pages(r1bio->bios[i]);
resync_free_pages(rp);
bio_put(r1bio->bios[i]);
}
/* resync pages array stored in the 1st bio's .bi_private */
kfree(rp);
rbio_pool_free(r1bio, data);
}
static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
{
int i;
for (i = 0; i < conf->raid_disks * 2; i++) {
struct bio **bio = r1_bio->bios + i;
if (!BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
}
}
static void free_r1bio(struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
put_all_bios(conf, r1_bio);
mempool_free(r1_bio, &conf->r1bio_pool);
}
static void put_buf(struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
sector_t sect = r1_bio->sector;
int i;
for (i = 0; i < conf->raid_disks * 2; i++) {
struct bio *bio = r1_bio->bios[i];
if (bio->bi_end_io)
rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
}
mempool_free(r1_bio, &conf->r1buf_pool);
lower_barrier(conf, sect);
}
static void reschedule_retry(struct r1bio *r1_bio)
{
unsigned long flags;
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
int idx;
idx = sector_to_idx(r1_bio->sector);
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&r1_bio->retry_list, &conf->retry_list);
atomic_inc(&conf->nr_queued[idx]);
spin_unlock_irqrestore(&conf->device_lock, flags);
wake_up(&conf->wait_barrier);
md_wakeup_thread(mddev->thread);
}
/*
* raid_end_bio_io() is called when we have finished servicing a mirrored
* operation and are ready to return a success/failure code to the buffer
* cache layer.
*/
static void call_bio_endio(struct r1bio *r1_bio)
{
struct bio *bio = r1_bio->master_bio;
if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
}
static void raid_end_bio_io(struct r1bio *r1_bio)
{
struct bio *bio = r1_bio->master_bio;
struct r1conf *conf = r1_bio->mddev->private;
/* if nobody has done the final endio yet, do it now */
if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
(bio_data_dir(bio) == WRITE) ? "write" : "read",
(unsigned long long) bio->bi_iter.bi_sector,
(unsigned long long) bio_end_sector(bio) - 1);
call_bio_endio(r1_bio);
}
/*
* Wake up any possible resync thread that waits for the device
* to go idle. All I/Os, even write-behind writes, are done.
*/
allow_barrier(conf, r1_bio->sector);
free_r1bio(r1_bio);
}
/*
* Update disk head position estimator based on IRQ completion info.
*/
static inline void update_head_pos(int disk, struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
conf->mirrors[disk].head_position =
r1_bio->sector + (r1_bio->sectors);
}
/*
* Find the disk number which triggered given bio
*/
static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
{
int mirror;
struct r1conf *conf = r1_bio->mddev->private;
int raid_disks = conf->raid_disks;
for (mirror = 0; mirror < raid_disks * 2; mirror++)
if (r1_bio->bios[mirror] == bio)
break;
BUG_ON(mirror == raid_disks * 2);
update_head_pos(mirror, r1_bio);
return mirror;
}
static void raid1_end_read_request(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r1bio *r1_bio = bio->bi_private;
struct r1conf *conf = r1_bio->mddev->private;
struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
update_head_pos(r1_bio->read_disk, r1_bio);
if (uptodate)
set_bit(R1BIO_Uptodate, &r1_bio->state);
else if (test_bit(FailFast, &rdev->flags) &&
test_bit(R1BIO_FailFast, &r1_bio->state))
/* This was a fail-fast read so we definitely
* want to retry */
;
else {
/* If all other devices have failed, we want to return
* the error upwards rather than fail the last device.
* Here we redefine "uptodate" to mean "Don't want to retry"
*/
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (r1_bio->mddev->degraded == conf->raid_disks ||
(r1_bio->mddev->degraded == conf->raid_disks-1 &&
test_bit(In_sync, &rdev->flags)))
uptodate = 1;
spin_unlock_irqrestore(&conf->device_lock, flags);
}
if (uptodate) {
raid_end_bio_io(r1_bio);
rdev_dec_pending(rdev, conf->mddev);
} else {
/*
* oops, read error:
*/
char b[BDEVNAME_SIZE];
pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
mdname(conf->mddev),
bdevname(rdev->bdev, b),
(unsigned long long)r1_bio->sector);
set_bit(R1BIO_ReadError, &r1_bio->state);
reschedule_retry(r1_bio);
/* don't drop the reference on read_disk yet */
}
}
static void close_write(struct r1bio *r1_bio)
{
/* it really is the end of this request */
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
bio_free_pages(r1_bio->behind_master_bio);
bio_put(r1_bio->behind_master_bio);
r1_bio->behind_master_bio = NULL;
}
/* clear the bitmap if all writes complete successfully */
md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
r1_bio->sectors,
!test_bit(R1BIO_Degraded, &r1_bio->state),
test_bit(R1BIO_BehindIO, &r1_bio->state));
md_write_end(r1_bio->mddev);
}
static void r1_bio_write_done(struct r1bio *r1_bio)
{
if (!atomic_dec_and_test(&r1_bio->remaining))
return;
if (test_bit(R1BIO_WriteError, &r1_bio->state))
reschedule_retry(r1_bio);
else {
close_write(r1_bio);
if (test_bit(R1BIO_MadeGood, &r1_bio->state))
reschedule_retry(r1_bio);
else
raid_end_bio_io(r1_bio);
}
}
static void raid1_end_write_request(struct bio *bio)
{
struct r1bio *r1_bio = bio->bi_private;
int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
struct r1conf *conf = r1_bio->mddev->private;
struct bio *to_put = NULL;
int mirror = find_bio_disk(r1_bio, bio);
struct md_rdev *rdev = conf->mirrors[mirror].rdev;
bool discard_error;
sector_t lo = r1_bio->sector;
sector_t hi = r1_bio->sector + r1_bio->sectors;
discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
/*
* 'one mirror IO has finished' event handler:
*/
if (bio->bi_status && !discard_error) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
conf->mddev->recovery);
if (test_bit(FailFast, &rdev->flags) &&
(bio->bi_opf & MD_FAILFAST) &&
/* We never try FailFast to WriteMostly devices */
!test_bit(WriteMostly, &rdev->flags)) {
md_error(r1_bio->mddev, rdev);
}
/*
* When the device is faulty, it is not necessary to
* handle write error.
* For failfast, this is the only remaining device,
* We need to retry the write without FailFast.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_WriteError, &r1_bio->state);
else {
/* Finished with this branch */
r1_bio->bios[mirror] = NULL;
to_put = bio;
}
} else {
/*
* Set R1BIO_Uptodate in our master bio, so that we
* will return a good error code for to the higher
* levels even if IO on some other mirrored buffer
* fails.
*
* The 'master' represents the composite IO operation
* to user-side. So if something waits for IO, then it
* will wait for the 'master' bio.
*/
sector_t first_bad;
int bad_sectors;
r1_bio->bios[mirror] = NULL;
to_put = bio;
/*
* Do not set R1BIO_Uptodate if the current device is
* rebuilding or Faulty. This is because we cannot use
* such device for properly reading the data back (we could
* potentially use it, if the current write would have felt
* before rdev->recovery_offset, but for simplicity we don't
* check this here.
*/
if (test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_Uptodate, &r1_bio->state);
/* Maybe we can clear some bad blocks. */
if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
&first_bad, &bad_sectors) && !discard_error) {
r1_bio->bios[mirror] = IO_MADE_GOOD;
set_bit(R1BIO_MadeGood, &r1_bio->state);
}
}
if (behind) {
if (test_bit(CollisionCheck, &rdev->flags))
remove_serial(rdev, lo, hi);
if (test_bit(WriteMostly, &rdev->flags))
atomic_dec(&r1_bio->behind_remaining);
/*
* In behind mode, we ACK the master bio once the I/O
* has safely reached all non-writemostly
* disks. Setting the Returned bit ensures that this
* gets done only once -- we don't ever want to return
* -EIO here, instead we'll wait
*/
if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
test_bit(R1BIO_Uptodate, &r1_bio->state)) {
/* Maybe we can return now */
if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
struct bio *mbio = r1_bio->master_bio;
pr_debug("raid1: behind end write sectors"
" %llu-%llu\n",
(unsigned long long) mbio->bi_iter.bi_sector,
(unsigned long long) bio_end_sector(mbio) - 1);
call_bio_endio(r1_bio);
}
}
} else if (rdev->mddev->serialize_policy)
remove_serial(rdev, lo, hi);
if (r1_bio->bios[mirror] == NULL)
rdev_dec_pending(rdev, conf->mddev);
/*
* Let's see if all mirrored write operations have finished
* already.
*/
r1_bio_write_done(r1_bio);
if (to_put)
bio_put(to_put);
}
static sector_t align_to_barrier_unit_end(sector_t start_sector,
sector_t sectors)
{
sector_t len;
WARN_ON(sectors == 0);
/*
* len is the number of sectors from start_sector to end of the
* barrier unit which start_sector belongs to.
*/
len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
start_sector;
if (len > sectors)
len = sectors;
return len;
}
/*
* This routine returns the disk from which the requested read should
* be done. There is a per-array 'next expected sequential IO' sector
* number - if this matches on the next IO then we use the last disk.
* There is also a per-disk 'last know head position' sector that is
* maintained from IRQ contexts, both the normal and the resync IO
* completion handlers update this position correctly. If there is no
* perfect sequential match then we pick the disk whose head is closest.
*
* If there are 2 mirrors in the same 2 devices, performance degrades
* because position is mirror, not device based.
*
* The rdev for the device selected will have nr_pending incremented.
*/
static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
{
const sector_t this_sector = r1_bio->sector;
int sectors;
int best_good_sectors;
int best_disk, best_dist_disk, best_pending_disk;
int has_nonrot_disk;
int disk;
sector_t best_dist;
unsigned int min_pending;
struct md_rdev *rdev;
int choose_first;
int choose_next_idle;
rcu_read_lock();
/*
* Check if we can balance. We can balance on the whole
* device if no resync is going on, or below the resync window.
* We take the first readable disk when above the resync window.
*/
retry:
sectors = r1_bio->sectors;
best_disk = -1;
best_dist_disk = -1;
best_dist = MaxSector;
best_pending_disk = -1;
min_pending = UINT_MAX;
best_good_sectors = 0;
has_nonrot_disk = 0;
choose_next_idle = 0;
clear_bit(R1BIO_FailFast, &r1_bio->state);
if ((conf->mddev->recovery_cp < this_sector + sectors) ||
(mddev_is_clustered(conf->mddev) &&
md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
this_sector + sectors)))
choose_first = 1;
else
choose_first = 0;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
sector_t dist;
sector_t first_bad;
int bad_sectors;
unsigned int pending;
bool nonrot;
rdev = rcu_dereference(conf->mirrors[disk].rdev);
if (r1_bio->bios[disk] == IO_BLOCKED
|| rdev == NULL
|| test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < this_sector + sectors)
continue;
if (test_bit(WriteMostly, &rdev->flags)) {
/* Don't balance among write-mostly, just
* use the first as a last resort */
if (best_dist_disk < 0) {
if (is_badblock(rdev, this_sector, sectors,
&first_bad, &bad_sectors)) {
if (first_bad <= this_sector)
/* Cannot use this */
continue;
best_good_sectors = first_bad - this_sector;
} else
best_good_sectors = sectors;
best_dist_disk = disk;
best_pending_disk = disk;
}
continue;
}
/* This is a reasonable device to use. It might
* even be best.
*/
if (is_badblock(rdev, this_sector, sectors,
&first_bad, &bad_sectors)) {
if (best_dist < MaxSector)
/* already have a better device */
continue;
if (first_bad <= this_sector) {
/* cannot read here. If this is the 'primary'
* device, then we must not read beyond
* bad_sectors from another device..
*/
bad_sectors -= (this_sector - first_bad);
if (choose_first && sectors > bad_sectors)
sectors = bad_sectors;
if (best_good_sectors > sectors)
best_good_sectors = sectors;
} else {
sector_t good_sectors = first_bad - this_sector;
if (good_sectors > best_good_sectors) {
best_good_sectors = good_sectors;
best_disk = disk;
}
if (choose_first)
break;
}
continue;
} else {
if ((sectors > best_good_sectors) && (best_disk >= 0))
best_disk = -1;
best_good_sectors = sectors;
}
if (best_disk >= 0)
/* At least two disks to choose from so failfast is OK */
set_bit(R1BIO_FailFast, &r1_bio->state);
nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
has_nonrot_disk |= nonrot;
pending = atomic_read(&rdev->nr_pending);
dist = abs(this_sector - conf->mirrors[disk].head_position);
if (choose_first) {
best_disk = disk;
break;
}
/* Don't change to another disk for sequential reads */
if (conf->mirrors[disk].next_seq_sect == this_sector
|| dist == 0) {
int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
struct raid1_info *mirror = &conf->mirrors[disk];
best_disk = disk;
/*
* If buffered sequential IO size exceeds optimal
* iosize, check if there is idle disk. If yes, choose
* the idle disk. read_balance could already choose an
* idle disk before noticing it's a sequential IO in
* this disk. This doesn't matter because this disk
* will idle, next time it will be utilized after the
* first disk has IO size exceeds optimal iosize. In
* this way, iosize of the first disk will be optimal
* iosize at least. iosize of the second disk might be
* small, but not a big deal since when the second disk
* starts IO, the first disk is likely still busy.
*/
if (nonrot && opt_iosize > 0 &&
mirror->seq_start != MaxSector &&
mirror->next_seq_sect > opt_iosize &&
mirror->next_seq_sect - opt_iosize >=
mirror->seq_start) {
choose_next_idle = 1;
continue;
}
break;
}
if (choose_next_idle)
continue;
if (min_pending > pending) {
min_pending = pending;
best_pending_disk = disk;
}
if (dist < best_dist) {
best_dist = dist;
best_dist_disk = disk;
}
}
/*
* If all disks are rotational, choose the closest disk. If any disk is
* non-rotational, choose the disk with less pending request even the
* disk is rotational, which might/might not be optimal for raids with
* mixed ratation/non-rotational disks depending on workload.
*/
if (best_disk == -1) {
if (has_nonrot_disk || min_pending == 0)
best_disk = best_pending_disk;
else
best_disk = best_dist_disk;
}
if (best_disk >= 0) {
rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
if (!rdev)
goto retry;
atomic_inc(&rdev->nr_pending);
sectors = best_good_sectors;
if (conf->mirrors[best_disk].next_seq_sect != this_sector)
conf->mirrors[best_disk].seq_start = this_sector;
conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
}
rcu_read_unlock();
*max_sectors = sectors;
return best_disk;
}
static int raid1_congested(struct mddev *mddev, int bits)
{
struct r1conf *conf = mddev->private;
int i, ret = 0;
if ((bits & (1 << WB_async_congested)) &&
conf->pending_count >= max_queued_requests)
return 1;
rcu_read_lock();
for (i = 0; i < conf->raid_disks * 2; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev && !test_bit(Faulty, &rdev->flags)) {
struct request_queue *q = bdev_get_queue(rdev->bdev);
BUG_ON(!q);
/* Note the '|| 1' - when read_balance prefers
* non-congested targets, it can be removed
*/
if ((bits & (1 << WB_async_congested)) || 1)
ret |= bdi_congested(q->backing_dev_info, bits);
else
ret &= bdi_congested(q->backing_dev_info, bits);
}
}
rcu_read_unlock();
return ret;
}
static void flush_bio_list(struct r1conf *conf, struct bio *bio)
{
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
md_bitmap_unplug(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
struct md_rdev *rdev = (void *)bio->bi_disk;
bio->bi_next = NULL;
bio_set_dev(bio, rdev->bdev);
if (test_bit(Faulty, &rdev->flags)) {
bio_io_error(bio);
} else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
!blk_queue_discard(bio->bi_disk->queue)))
/* Just ignore it */
bio_endio(bio);
else
generic_make_request(bio);
bio = next;
cond_resched();
}
}
static void flush_pending_writes(struct r1conf *conf)
{
/* Any writes that have been queued but are awaiting
* bitmap updates get flushed here.
*/
spin_lock_irq(&conf->device_lock);
if (conf->pending_bio_list.head) {
struct blk_plug plug;
struct bio *bio;
bio = bio_list_get(&conf->pending_bio_list);
conf->pending_count = 0;
spin_unlock_irq(&conf->device_lock);
/*
* As this is called in a wait_event() loop (see freeze_array),
* current->state might be TASK_UNINTERRUPTIBLE which will
* cause a warning when we prepare to wait again. As it is
* rare that this path is taken, it is perfectly safe to force
* us to go around the wait_event() loop again, so the warning
* is a false-positive. Silence the warning by resetting
* thread state
*/
__set_current_state(TASK_RUNNING);
blk_start_plug(&plug);
flush_bio_list(conf, bio);
blk_finish_plug(&plug);
} else
spin_unlock_irq(&conf->device_lock);
}
/* Barriers....
* Sometimes we need to suspend IO while we do something else,
* either some resync/recovery, or reconfigure the array.
* To do this we raise a 'barrier'.
* The 'barrier' is a counter that can be raised multiple times
* to count how many activities are happening which preclude
* normal IO.
* We can only raise the barrier if there is no pending IO.
* i.e. if nr_pending == 0.
* We choose only to raise the barrier if no-one is waiting for the
* barrier to go down. This means that as soon as an IO request
* is ready, no other operations which require a barrier will start
* until the IO request has had a chance.
*
* So: regular IO calls 'wait_barrier'. When that returns there
* is no backgroup IO happening, It must arrange to call
* allow_barrier when it has finished its IO.
* backgroup IO calls must call raise_barrier. Once that returns
* there is no normal IO happeing. It must arrange to call
* lower_barrier when the particular background IO completes.
*
* If resync/recovery is interrupted, returns -EINTR;
* Otherwise, returns 0.
*/
static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
spin_lock_irq(&conf->resync_lock);
/* Wait until no block IO is waiting */
wait_event_lock_irq(conf->wait_barrier,
!atomic_read(&conf->nr_waiting[idx]),
conf->resync_lock);
/* block any new IO from starting */
atomic_inc(&conf->barrier[idx]);
/*
* In raise_barrier() we firstly increase conf->barrier[idx] then
* check conf->nr_pending[idx]. In _wait_barrier() we firstly
* increase conf->nr_pending[idx] then check conf->barrier[idx].
* A memory barrier here to make sure conf->nr_pending[idx] won't
* be fetched before conf->barrier[idx] is increased. Otherwise
* there will be a race between raise_barrier() and _wait_barrier().
*/
smp_mb__after_atomic();
/* For these conditions we must wait:
* A: while the array is in frozen state
* B: while conf->nr_pending[idx] is not 0, meaning regular I/O
* existing in corresponding I/O barrier bucket.
* C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
* max resync count which allowed on current I/O barrier bucket.
*/
wait_event_lock_irq(conf->wait_barrier,
(!conf->array_frozen &&
!atomic_read(&conf->nr_pending[idx]) &&
atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
conf->resync_lock);
if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
atomic_dec(&conf->barrier[idx]);
spin_unlock_irq(&conf->resync_lock);
wake_up(&conf->wait_barrier);
return -EINTR;
}
atomic_inc(&conf->nr_sync_pending);
spin_unlock_irq(&conf->resync_lock);
return 0;
}
static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
atomic_dec(&conf->barrier[idx]);
atomic_dec(&conf->nr_sync_pending);
wake_up(&conf->wait_barrier);
}
static void _wait_barrier(struct r1conf *conf, int idx)
{
/*
* We need to increase conf->nr_pending[idx] very early here,
* then raise_barrier() can be blocked when it waits for
* conf->nr_pending[idx] to be 0. Then we can avoid holding
* conf->resync_lock when there is no barrier raised in same
* barrier unit bucket. Also if the array is frozen, I/O
* should be blocked until array is unfrozen.
*/
atomic_inc(&conf->nr_pending[idx]);
/*
* In _wait_barrier() we firstly increase conf->nr_pending[idx], then
* check conf->barrier[idx]. In raise_barrier() we firstly increase
* conf->barrier[idx], then check conf->nr_pending[idx]. A memory
* barrier is necessary here to make sure conf->barrier[idx] won't be
* fetched before conf->nr_pending[idx] is increased. Otherwise there
* will be a race between _wait_barrier() and raise_barrier().
*/
smp_mb__after_atomic();
/*
* Don't worry about checking two atomic_t variables at same time
* here. If during we check conf->barrier[idx], the array is
* frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
* 0, it is safe to return and make the I/O continue. Because the
* array is frozen, all I/O returned here will eventually complete
* or be queued, no race will happen. See code comment in
* frozen_array().
*/
if (!READ_ONCE(conf->array_frozen) &&
!atomic_read(&conf->barrier[idx]))
return;
/*
* After holding conf->resync_lock, conf->nr_pending[idx]
* should be decreased before waiting for barrier to drop.
* Otherwise, we may encounter a race condition because
* raise_barrer() might be waiting for conf->nr_pending[idx]
* to be 0 at same time.
*/
spin_lock_irq(&conf->resync_lock);
atomic_inc(&conf->nr_waiting[idx]);
atomic_dec(&conf->nr_pending[idx]);
/*
* In case freeze_array() is waiting for
* get_unqueued_pending() == extra
*/
wake_up(&conf->wait_barrier);
/* Wait for the barrier in same barrier unit bucket to drop. */
wait_event_lock_irq(conf->wait_barrier,
!conf->array_frozen &&
!atomic_read(&conf->barrier[idx]),
conf->resync_lock);
atomic_inc(&conf->nr_pending[idx]);
atomic_dec(&conf->nr_waiting[idx]);
spin_unlock_irq(&conf->resync_lock);
}
static void wait_read_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
/*
* Very similar to _wait_barrier(). The difference is, for read
* I/O we don't need wait for sync I/O, but if the whole array
* is frozen, the read I/O still has to wait until the array is
* unfrozen. Since there is no ordering requirement with
* conf->barrier[idx] here, memory barrier is unnecessary as well.
*/
atomic_inc(&conf->nr_pending[idx]);
if (!READ_ONCE(conf->array_frozen))
return;
spin_lock_irq(&conf->resync_lock);
atomic_inc(&conf->nr_waiting[idx]);
atomic_dec(&conf->nr_pending[idx]);
/*
* In case freeze_array() is waiting for
* get_unqueued_pending() == extra
*/
wake_up(&conf->wait_barrier);
/* Wait for array to be unfrozen */
wait_event_lock_irq(conf->wait_barrier,
!conf->array_frozen,
conf->resync_lock);
atomic_inc(&conf->nr_pending[idx]);
atomic_dec(&conf->nr_waiting[idx]);
spin_unlock_irq(&conf->resync_lock);
}
static void wait_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
_wait_barrier(conf, idx);
}
static void _allow_barrier(struct r1conf *conf, int idx)
{
atomic_dec(&conf->nr_pending[idx]);
wake_up(&conf->wait_barrier);
}
static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
_allow_barrier(conf, idx);
}
/* conf->resync_lock should be held */
static int get_unqueued_pending(struct r1conf *conf)
{
int idx, ret;
ret = atomic_read(&conf->nr_sync_pending);
for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
ret += atomic_read(&conf->nr_pending[idx]) -
atomic_read(&conf->nr_queued[idx]);
return ret;
}
static void freeze_array(struct r1conf *conf, int extra)
{
/* Stop sync I/O and normal I/O and wait for everything to
* go quiet.
* This is called in two situations:
* 1) management command handlers (reshape, remove disk, quiesce).
* 2) one normal I/O request failed.
* After array_frozen is set to 1, new sync IO will be blocked at
* raise_barrier(), and new normal I/O will blocked at _wait_barrier()
* or wait_read_barrier(). The flying I/Os will either complete or be
* queued. When everything goes quite, there are only queued I/Os left.
* Every flying I/O contributes to a conf->nr_pending[idx], idx is the
* barrier bucket index which this I/O request hits. When all sync and
* normal I/O are queued, sum of all conf->nr_pending[] will match sum
* of all conf->nr_queued[]. But normal I/O failure is an exception,
* in handle_read_error(), we may call freeze_array() before trying to
* fix the read error. In this case, the error read I/O is not queued,
* so get_unqueued_pending() == 1.
*
* Therefore before this function returns, we need to wait until
* get_unqueued_pendings(conf) gets equal to extra. For
* normal I/O context, extra is 1, in rested situations extra is 0.
*/
spin_lock_irq(&conf->resync_lock);
conf->array_frozen = 1;
raid1_log(conf->mddev, "wait freeze");
wait_event_lock_irq_cmd(
conf->wait_barrier,
get_unqueued_pending(conf) == extra,
conf->resync_lock,
flush_pending_writes(conf));
spin_unlock_irq(&conf->resync_lock);
}
static void unfreeze_array(struct r1conf *conf)
{
/* reverse the effect of the freeze */
spin_lock_irq(&conf->resync_lock);
conf->array_frozen = 0;
spin_unlock_irq(&conf->resync_lock);
wake_up(&conf->wait_barrier);
}
static void alloc_behind_master_bio(struct r1bio *r1_bio,
struct bio *bio)
{
int size = bio->bi_iter.bi_size;
unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
int i = 0;
struct bio *behind_bio = NULL;
behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev);
if (!behind_bio)
return;
/* discard op, we don't support writezero/writesame yet */
if (!bio_has_data(bio)) {
behind_bio->bi_iter.bi_size = size;
goto skip_copy;
}
behind_bio->bi_write_hint = bio->bi_write_hint;
while (i < vcnt && size) {
struct page *page;
int len = min_t(int, PAGE_SIZE, size);
page = alloc_page(GFP_NOIO);
if (unlikely(!page))
goto free_pages;
bio_add_page(behind_bio, page, len, 0);
size -= len;
i++;
}
bio_copy_data(behind_bio, bio);
skip_copy:
r1_bio->behind_master_bio = behind_bio;
set_bit(R1BIO_BehindIO, &r1_bio->state);
return;
free_pages:
pr_debug("%dB behind alloc failed, doing sync I/O\n",
bio->bi_iter.bi_size);
bio_free_pages(behind_bio);
bio_put(behind_bio);
}
struct raid1_plug_cb {
struct blk_plug_cb cb;
struct bio_list pending;
int pending_cnt;
};
static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
cb);
struct mddev *mddev = plug->cb.data;
struct r1conf *conf = mddev->private;
struct bio *bio;
if (from_schedule || current->bio_list) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
conf->pending_count += plug->pending_cnt;
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_barrier);
md_wakeup_thread(mddev->thread);
kfree(plug);
return;
}
/* we aren't scheduling, so we can do the write-out directly. */
bio = bio_list_get(&plug->pending);
flush_bio_list(conf, bio);
kfree(plug);
}
static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
{
r1_bio->master_bio = bio;
r1_bio->sectors = bio_sectors(bio);
r1_bio->state = 0;
r1_bio->mddev = mddev;
r1_bio->sector = bio->bi_iter.bi_sector;
}
static inline struct r1bio *
alloc_r1bio(struct mddev *mddev, struct bio *bio)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
/* Ensure no bio records IO_BLOCKED */
memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
init_r1bio(r1_bio, mddev, bio);
return r1_bio;
}
static void raid1_read_request(struct mddev *mddev, struct bio *bio,
int max_read_sectors, struct r1bio *r1_bio)
{
struct r1conf *conf = mddev->private;
struct raid1_info *mirror;
struct bio *read_bio;
struct bitmap *bitmap = mddev->bitmap;
const int op = bio_op(bio);
const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
int max_sectors;
int rdisk;
bool print_msg = !!r1_bio;
char b[BDEVNAME_SIZE];
/*
* If r1_bio is set, we are blocking the raid1d thread
* so there is a tiny risk of deadlock. So ask for
* emergency memory if needed.
*/
gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
if (print_msg) {
/* Need to get the block device name carefully */
struct md_rdev *rdev;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
if (rdev)
bdevname(rdev->bdev, b);
else
strcpy(b, "???");
rcu_read_unlock();
}
/*
* Still need barrier for READ in case that whole
* array is frozen.
*/
wait_read_barrier(conf, bio->bi_iter.bi_sector);
if (!r1_bio)
r1_bio = alloc_r1bio(mddev, bio);
else
init_r1bio(r1_bio, mddev, bio);
r1_bio->sectors = max_read_sectors;
/*
* make_request() can abort the operation when read-ahead is being
* used and no empty request is available.
*/
rdisk = read_balance(conf, r1_bio, &max_sectors);
if (rdisk < 0) {
/* couldn't find anywhere to read from */
if (print_msg) {
pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev),
b,
(unsigned long long)r1_bio->sector);
}
raid_end_bio_io(r1_bio);
return;
}
mirror = conf->mirrors + rdisk;
if (print_msg)
pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
mdname(mddev),
(unsigned long long)r1_bio->sector,
bdevname(mirror->rdev->bdev, b));
if (test_bit(WriteMostly, &mirror->rdev->flags) &&
bitmap) {
/*
* Reading from a write-mostly device must take care not to
* over-take any writes that are 'behind'
*/
raid1_log(mddev, "wait behind writes");
wait_event(bitmap->behind_wait,
atomic_read(&bitmap->behind_writes) == 0);
}
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
gfp, &conf->bio_split);
bio_chain(split, bio);
generic_make_request(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
r1_bio->read_disk = rdisk;
read_bio = bio_clone_fast(bio, gfp, &mddev->bio_set);
r1_bio->bios[rdisk] = read_bio;
read_bio->bi_iter.bi_sector = r1_bio->sector +
mirror->rdev->data_offset;
bio_set_dev(read_bio, mirror->rdev->bdev);
read_bio->bi_end_io = raid1_end_read_request;
bio_set_op_attrs(read_bio, op, do_sync);
if (test_bit(FailFast, &mirror->rdev->flags) &&
test_bit(R1BIO_FailFast, &r1_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
read_bio->bi_private = r1_bio;
if (mddev->gendisk)
trace_block_bio_remap(read_bio->bi_disk->queue, read_bio,
disk_devt(mddev->gendisk), r1_bio->sector);
generic_make_request(read_bio);
}
static void raid1_write_request(struct mddev *mddev, struct bio *bio,
int max_write_sectors)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
int i, disks;
struct bitmap *bitmap = mddev->bitmap;
unsigned long flags;
struct md_rdev *blocked_rdev;
struct blk_plug_cb *cb;
struct raid1_plug_cb *plug = NULL;
int first_clone;
int max_sectors;
if (mddev_is_clustered(mddev) &&
md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector, bio_end_sector(bio))) {
DEFINE_WAIT(w);
for (;;) {
prepare_to_wait(&conf->wait_barrier,
&w, TASK_IDLE);
if (!md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector,
bio_end_sector(bio)))
break;
schedule();
}
finish_wait(&conf->wait_barrier, &w);
}
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
*/
wait_barrier(conf, bio->bi_iter.bi_sector);
r1_bio = alloc_r1bio(mddev, bio);
r1_bio->sectors = max_write_sectors;
if (conf->pending_count >= max_queued_requests) {
md_wakeup_thread(mddev->thread);
raid1_log(mddev, "wait queued");
wait_event(conf->wait_barrier,
conf->pending_count < max_queued_requests);
}
/* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
* If there are known/acknowledged bad blocks on any device on
* which we have seen a write error, we want to avoid writing those
* blocks.
* This potentially requires several writes to write around
* the bad blocks. Each set of writes gets it's own r1bio
* with a set of bios attached.
*/
disks = conf->raid_disks * 2;
retry_write:
blocked_rdev = NULL;
rcu_read_lock();
max_sectors = r1_bio->sectors;
for (i = 0; i < disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
r1_bio->bios[i] = NULL;
if (!rdev || test_bit(Faulty, &rdev->flags)) {
if (i < conf->raid_disks)
set_bit(R1BIO_Degraded, &r1_bio->state);
continue;
}
atomic_inc(&rdev->nr_pending);
if (test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
int bad_sectors;
int is_bad;
is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
&first_bad, &bad_sectors);
if (is_bad < 0) {
/* mustn't write here until the bad block is
* acknowledged*/
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
if (is_bad && first_bad <= r1_bio->sector) {
/* Cannot write here at all */
bad_sectors -= (r1_bio->sector - first_bad);
if (bad_sectors < max_sectors)
/* mustn't write more than bad_sectors
* to other devices yet
*/
max_sectors = bad_sectors;
rdev_dec_pending(rdev, mddev);
/* We don't set R1BIO_Degraded as that
* only applies if the disk is
* missing, so it might be re-added,
* and we want to know to recover this
* chunk.
* In this case the device is here,
* and the fact that this chunk is not
* in-sync is recorded in the bad
* block log
*/
continue;
}
if (is_bad) {
int good_sectors = first_bad - r1_bio->sector;
if (good_sectors < max_sectors)
max_sectors = good_sectors;
}
}
r1_bio->bios[i] = bio;
}
rcu_read_unlock();
if (unlikely(blocked_rdev)) {
/* Wait for this device to become unblocked */
int j;
for (j = 0; j < i; j++)
if (r1_bio->bios[j])
rdev_dec_pending(conf->mirrors[j].rdev, mddev);
r1_bio->state = 0;
allow_barrier(conf, bio->bi_iter.bi_sector);
raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf, bio->bi_iter.bi_sector);
goto retry_write;
}
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
generic_make_request(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
atomic_set(&r1_bio->remaining, 1);
atomic_set(&r1_bio->behind_remaining, 0);
first_clone = 1;
for (i = 0; i < disks; i++) {
struct bio *mbio = NULL;
struct md_rdev *rdev = conf->mirrors[i].rdev;
if (!r1_bio->bios[i])
continue;
if (first_clone) {
/* do behind I/O ?
* Not if there are too many, or cannot
* allocate memory, or a reader on WriteMostly
* is waiting for behind writes to flush */
if (bitmap &&
(atomic_read(&bitmap->behind_writes)
< mddev->bitmap_info.max_write_behind) &&
!waitqueue_active(&bitmap->behind_wait)) {
alloc_behind_master_bio(r1_bio, bio);
}
md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
test_bit(R1BIO_BehindIO, &r1_bio->state));
first_clone = 0;
}
if (r1_bio->behind_master_bio)
mbio = bio_clone_fast(r1_bio->behind_master_bio,
GFP_NOIO, &mddev->bio_set);
else
mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set);
if (r1_bio->behind_master_bio) {
if (test_bit(CollisionCheck, &rdev->flags))
wait_for_serialization(rdev, r1_bio);
if (test_bit(WriteMostly, &rdev->flags))
atomic_inc(&r1_bio->behind_remaining);
} else if (mddev->serialize_policy)
wait_for_serialization(rdev, r1_bio);
r1_bio->bios[i] = mbio;
mbio->bi_iter.bi_sector = (r1_bio->sector +
conf->mirrors[i].rdev->data_offset);
bio_set_dev(mbio, conf->mirrors[i].rdev->bdev);
mbio->bi_end_io = raid1_end_write_request;
mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
!test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
conf->raid_disks - mddev->degraded > 1)
mbio->bi_opf |= MD_FAILFAST;
mbio->bi_private = r1_bio;
atomic_inc(&r1_bio->remaining);
if (mddev->gendisk)
trace_block_bio_remap(mbio->bi_disk->queue,
mbio, disk_devt(mddev->gendisk),
r1_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_disk = (void *)conf->mirrors[i].rdev;
cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
if (cb)
plug = container_of(cb, struct raid1_plug_cb, cb);
else
plug = NULL;
if (plug) {
bio_list_add(&plug->pending, mbio);
plug->pending_cnt++;
} else {
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
conf->pending_count++;
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(mddev->thread);
}
}
r1_bio_write_done(r1_bio);
/* In case raid1d snuck in to freeze_array */
wake_up(&conf->wait_barrier);
}
static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
{
sector_t sectors;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
/*
* There is a limit to the maximum size, but
* the read/write handler might find a lower limit
* due to bad blocks. To avoid multiple splits,
* we pass the maximum number of sectors down
* and let the lower level perform the split.
*/
sectors = align_to_barrier_unit_end(
bio->bi_iter.bi_sector, bio_sectors(bio));
if (bio_data_dir(bio) == READ)
raid1_read_request(mddev, bio, sectors, NULL);
else {
if (!md_write_start(mddev,bio))
return false;
raid1_write_request(mddev, bio, sectors);
}
return true;
}
static void raid1_status(struct seq_file *seq, struct mddev *mddev)
{
struct r1conf *conf = mddev->private;
int i;
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
seq_printf(seq, "%s",
rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_printf(seq, "]");
}
static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
{
char b[BDEVNAME_SIZE];
struct r1conf *conf = mddev->private;
unsigned long flags;
/*
* If it is not operational, then we have already marked it as dead
* else if it is the last working disks with "fail_last_dev == false",
* ignore the error, let the next level up know.
* else mark the drive as failed
*/
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) && !mddev->fail_last_dev
&& (conf->raid_disks - mddev->degraded) == 1) {
/*
* Don't fail the drive, act as though we were just a
* normal single drive.
* However don't try a recovery from this drive as
* it is very likely to fail.
*/
conf->recovery_disabled = mddev->recovery_disabled;
spin_unlock_irqrestore(&conf->device_lock, flags);
return;
}
set_bit(Blocked, &rdev->flags);
if (test_and_clear_bit(In_sync, &rdev->flags))
mddev->degraded++;
set_bit(Faulty, &rdev->flags);
spin_unlock_irqrestore(&conf->device_lock, flags);
/*
* if recovery is running, make sure it aborts.
*/
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
"md/raid1:%s: Operation continuing on %d devices.\n",
mdname(mddev), bdevname(rdev->bdev, b),
mdname(mddev), conf->raid_disks - mddev->degraded);
}
static void print_conf(struct r1conf *conf)
{
int i;
pr_debug("RAID1 conf printout:\n");
if (!conf) {
pr_debug("(!conf)\n");
return;
}
pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
conf->raid_disks);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
char b[BDEVNAME_SIZE];
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev)
pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
i, !test_bit(In_sync, &rdev->flags),
!test_bit(Faulty, &rdev->flags),
bdevname(rdev->bdev,b));
}
rcu_read_unlock();
}
static void close_sync(struct r1conf *conf)
{
int idx;
for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
_wait_barrier(conf, idx);
_allow_barrier(conf, idx);
}
mempool_exit(&conf->r1buf_pool);
}
static int raid1_spare_active(struct mddev *mddev)
{
int i;
struct r1conf *conf = mddev->private;
int count = 0;
unsigned long flags;
/*
* Find all failed disks within the RAID1 configuration
* and mark them readable.
* Called under mddev lock, so rcu protection not needed.
* device_lock used to avoid races with raid1_end_read_request
* which expects 'In_sync' flags and ->degraded to be consistent.
*/
spin_lock_irqsave(&conf->device_lock, flags);
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
if (repl
&& !test_bit(Candidate, &repl->flags)
&& repl->recovery_offset == MaxSector
&& !test_bit(Faulty, &repl->flags)
&& !test_and_set_bit(In_sync, &repl->flags)) {
/* replacement has just become active */
if (!rdev ||
!test_and_clear_bit(In_sync, &rdev->flags))
count++;
if (rdev) {
/* Replaced device not technically
* faulty, but we need to be sure
* it gets removed and never re-added
*/
set_bit(Faulty, &rdev->flags);
sysfs_notify_dirent_safe(
rdev->sysfs_state);
}
}
if (rdev
&& rdev->recovery_offset == MaxSector
&& !test_bit(Faulty, &rdev->flags)
&& !test_and_set_bit(In_sync, &rdev->flags)) {
count++;
sysfs_notify_dirent_safe(rdev->sysfs_state);
}
}
mddev->degraded -= count;
spin_unlock_irqrestore(&conf->device_lock, flags);
print_conf(conf);
return count;
}
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
int err = -EEXIST;
int mirror = 0;
struct raid1_info *p;
int first = 0;
int last = conf->raid_disks - 1;
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;
if (md_integrity_add_rdev(rdev, mddev))
return -ENXIO;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
/*
* find the disk ... but prefer rdev->saved_raid_disk
* if possible.
*/
if (rdev->saved_raid_disk >= 0 &&
rdev->saved_raid_disk >= first &&
rdev->saved_raid_disk < conf->raid_disks &&
conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
first = last = rdev->saved_raid_disk;
for (mirror = first; mirror <= last; mirror++) {
p = conf->mirrors + mirror;
if (!p->rdev) {
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
p->head_position = 0;
rdev->raid_disk = mirror;
err = 0;
/* As all devices are equivalent, we don't need a full recovery
* if this was recently any drive of the array
*/
if (rdev->saved_raid_disk < 0)
conf->fullsync = 1;
rcu_assign_pointer(p->rdev, rdev);
break;
}
if (test_bit(WantReplacement, &p->rdev->flags) &&
p[conf->raid_disks].rdev == NULL) {
/* Add this device as a replacement */
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = mirror;
err = 0;
conf->fullsync = 1;
rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
break;
}
}
if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
print_conf(conf);
return err;
}
static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct raid1_info *p = conf->mirrors + number;
if (rdev != p->rdev)
p = conf->mirrors + conf->raid_disks + number;
print_conf(conf);
if (rdev == p->rdev) {
if (test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending)) {
err = -EBUSY;
goto abort;
}
/* Only remove non-faulty devices if recovery
* is not possible.
*/
if (!test_bit(Faulty, &rdev->flags) &&
mddev->recovery_disabled != conf->recovery_disabled &&
mddev->degraded < conf->raid_disks) {
err = -EBUSY;
goto abort;
}
p->rdev = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
p->rdev = rdev;
goto abort;
}
}
if (conf->mirrors[conf->raid_disks + number].rdev) {
/* We just removed a device that is being replaced.
* Move down the replacement. We drain all IO before
* doing this to avoid confusion.
*/
struct md_rdev *repl =
conf->mirrors[conf->raid_disks + number].rdev;
freeze_array(conf, 0);
if (atomic_read(&repl->nr_pending)) {
/* It means that some queued IO of retry_list
* hold repl. Thus, we cannot set replacement
* as NULL, avoiding rdev NULL pointer
* dereference in sync_request_write and
* handle_write_finished.
*/
err = -EBUSY;
unfreeze_array(conf);
goto abort;
}
clear_bit(Replacement, &repl->flags);
p->rdev = repl;
conf->mirrors[conf->raid_disks + number].rdev = NULL;
unfreeze_array(conf);
}
clear_bit(WantReplacement, &rdev->flags);
err = md_integrity_register(mddev);
}
abort:
print_conf(conf);
return err;
}
static void end_sync_read(struct bio *bio)
{
struct r1bio *r1_bio = get_resync_r1bio(bio);
update_head_pos(r1_bio->read_disk, r1_bio);
/*
* we have read a block, now it needs to be re-written,
* or re-read if the read failed.
* We don't do much here, just schedule handling by raid1d
*/
if (!bio->bi_status)
set_bit(R1BIO_Uptodate, &r1_bio->state);
if (atomic_dec_and_test(&r1_bio->remaining))
reschedule_retry(r1_bio);
}
static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
{
sector_t sync_blocks = 0;
sector_t s = r1_bio->sector;
long sectors_to_go = r1_bio->sectors;
/* make sure these bits don't get cleared. */
do {
md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
s += sync_blocks;
sectors_to_go -= sync_blocks;
} while (sectors_to_go > 0);
}
static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
{
if (atomic_dec_and_test(&r1_bio->remaining)) {
struct mddev *mddev = r1_bio->mddev;
int s = r1_bio->sectors;
if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
reschedule_retry(r1_bio);
else {
put_buf(r1_bio);
md_done_sync(mddev, s, uptodate);
}
}
}
static void end_sync_write(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r1bio *r1_bio = get_resync_r1bio(bio);
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
sector_t first_bad;
int bad_sectors;
struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
if (!uptodate) {
abort_sync_write(mddev, r1_bio);
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
mddev->recovery);
set_bit(R1BIO_WriteError, &r1_bio->state);
} else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
&first_bad, &bad_sectors) &&
!is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
r1_bio->sector,
r1_bio->sectors,
&first_bad, &bad_sectors)
)
set_bit(R1BIO_MadeGood, &r1_bio->state);
put_sync_write_buf(r1_bio, uptodate);
}
static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
int sectors, struct page *page, int rw)
{
if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
/* success */
return 1;
if (rw == WRITE) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement,
&rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
rdev->mddev->recovery);
}
/* need to record an error - either for the block or the device */
if (!rdev_set_badblocks(rdev, sector, sectors, 0))
md_error(rdev->mddev, rdev);
return 0;
}
static int fix_sync_read_error(struct r1bio *r1_bio)
{
/* Try some synchronous reads of other devices to get
* good data, much like with normal read errors. Only
* read into the pages we already have so we don't
* need to re-issue the read request.
* We don't need to freeze the array, because being in an
* active sync request, there is no normal IO, and
* no overlapping syncs.
* We don't need to check is_badblock() again as we
* made sure that anything with a bad block in range
* will have bi_end_io clear.
*/
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
struct bio *bio = r1_bio->bios[r1_bio->read_disk];
struct page **pages = get_resync_pages(bio)->pages;
sector_t sect = r1_bio->sector;
int sectors = r1_bio->sectors;
int idx = 0;
struct md_rdev *rdev;
rdev = conf->mirrors[r1_bio->read_disk].rdev;
if (test_bit(FailFast, &rdev->flags)) {
/* Don't try recovering from here - just fail it
* ... unless it is the last working device of course */
md_error(mddev, rdev);
if (test_bit(Faulty, &rdev->flags))
/* Don't try to read from here, but make sure
* put_buf does it's thing
*/
bio->bi_end_io = end_sync_write;
}
while(sectors) {
int s = sectors;
int d = r1_bio->read_disk;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
/* No rcu protection needed here devices
* can only be removed when no resync is
* active, and resync is currently active
*/
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev, sect, s<<9,
pages[idx],
REQ_OP_READ, 0, false)) {
success = 1;
break;
}
}
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (!success && d != r1_bio->read_disk);
if (!success) {
char b[BDEVNAME_SIZE];
int abort = 0;
/* Cannot read from anywhere, this block is lost.
* Record a bad block on each device. If that doesn't
* work just disable and interrupt the recovery.
* Don't fail devices as that won't really help.
*/
pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev), bio_devname(bio, b),
(unsigned long long)r1_bio->sector);
for (d = 0; d < conf->raid_disks * 2; d++) {
rdev = conf->mirrors[d].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags))
continue;
if (!rdev_set_badblocks(rdev, sect, s, 0))
abort = 1;
}
if (abort) {
conf->recovery_disabled =
mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_done_sync(mddev, r1_bio->sectors, 0);
put_buf(r1_bio);
return 0;
}
/* Try next page */
sectors -= s;
sect += s;
idx++;
continue;
}
start = d;
/* write it back and re-read */
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks * 2;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (r1_sync_page_io(rdev, sect, s,
pages[idx],
WRITE) == 0) {
r1_bio->bios[d]->bi_end_io = NULL;
rdev_dec_pending(rdev, mddev);
}
}
d = start;
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks * 2;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (r1_sync_page_io(rdev, sect, s,
pages[idx],
READ) != 0)
atomic_add(s, &rdev->corrected_errors);
}
sectors -= s;
sect += s;
idx ++;
}
set_bit(R1BIO_Uptodate, &r1_bio->state);
bio->bi_status = 0;
return 1;
}
static void process_checks(struct r1bio *r1_bio)
{
/* We have read all readable devices. If we haven't
* got the block, then there is no hope left.
* If we have, then we want to do a comparison
* and skip the write if everything is the same.
* If any blocks failed to read, then we need to
* attempt an over-write
*/
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
int primary;
int i;
int vcnt;
/* Fix variable parts of all bios */
vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
for (i = 0; i < conf->raid_disks * 2; i++) {
blk_status_t status;
struct bio *b = r1_bio->bios[i];
struct resync_pages *rp = get_resync_pages(b);
if (b->bi_end_io != end_sync_read)
continue;
/* fixup the bio for reuse, but preserve errno */
status = b->bi_status;
bio_reset(b);
b->bi_status = status;
b->bi_iter.bi_sector = r1_bio->sector +
conf->mirrors[i].rdev->data_offset;
bio_set_dev(b, conf->mirrors[i].rdev->bdev);
b->bi_end_io = end_sync_read;
rp->raid_bio = r1_bio;
b->bi_private = rp;
/* initialize bvec table again */
md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
}
for (primary = 0; primary < conf->raid_disks * 2; primary++)
if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
!r1_bio->bios[primary]->bi_status) {
r1_bio->bios[primary]->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
break;
}
r1_bio->read_disk = primary;
for (i = 0; i < conf->raid_disks * 2; i++) {
int j = 0;
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];
blk_status_t status = sbio->bi_status;
struct page **ppages = get_resync_pages(pbio)->pages;
struct page **spages = get_resync_pages(sbio)->pages;
struct bio_vec *bi;
int page_len[RESYNC_PAGES] = { 0 };
struct bvec_iter_all iter_all;
if (sbio->bi_end_io != end_sync_read)
continue;
/* Now we can 'fixup' the error value */
sbio->bi_status = 0;
bio_for_each_segment_all(bi, sbio, iter_all)
page_len[j++] = bi->bv_len;
if (!status) {
for (j = vcnt; j-- ; ) {
if (memcmp(page_address(ppages[j]),
page_address(spages[j]),
page_len[j]))
break;
}
} else
j = 0;
if (j >= 0)
atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
&& !status)) {
/* No need to write to this device. */
sbio->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[i].rdev, mddev);
continue;
}
bio_copy_data(sbio, pbio);
}
}
static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
{
struct r1conf *conf = mddev->private;
int i;
int disks = conf->raid_disks * 2;
struct bio *wbio;
if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
/* ouch - failed to read all of that. */
if (!fix_sync_read_error(r1_bio))
return;
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
process_checks(r1_bio);
/*
* schedule writes
*/
atomic_set(&r1_bio->remaining, 1);
for (i = 0; i < disks ; i++) {
wbio = r1_bio->bios[i];
if (wbio->bi_end_io == NULL ||
(wbio->bi_end_io == end_sync_read &&
(i == r1_bio->read_disk ||
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
continue;
if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
abort_sync_write(mddev, r1_bio);
continue;
}
bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
wbio->bi_opf |= MD_FAILFAST;
wbio->bi_end_io = end_sync_write;
atomic_inc(&r1_bio->remaining);
md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
generic_make_request(wbio);
}
put_sync_write_buf(r1_bio, 1);
}
/*
* This is a kernel thread which:
*
* 1. Retries failed read operations on working mirrors.
* 2. Updates the raid superblock when problems encounter.
* 3. Performs writes following reads for array synchronising.
*/
static void fix_read_error(struct r1conf *conf, int read_disk,
sector_t sect, int sectors)
{
struct mddev *mddev = conf->mddev;
while(sectors) {
int s = sectors;
int d = read_disk;
int success = 0;
int start;
struct md_rdev *rdev;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
sector_t first_bad;
int bad_sectors;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
(test_bit(In_sync, &rdev->flags) ||
(!test_bit(Faulty, &rdev->flags) &&
rdev->recovery_offset >= sect + s)) &&
is_badblock(rdev, sect, s,
&first_bad, &bad_sectors) == 0) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (sync_page_io(rdev, sect, s<<9,
conf->tmppage, REQ_OP_READ, 0, false))
success = 1;
rdev_dec_pending(rdev, mddev);
if (success)
break;
} else
rcu_read_unlock();
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (!success && d != read_disk);
if (!success) {
/* Cannot read from anywhere - mark it bad */
struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
if (!rdev_set_badblocks(rdev, sect, s, 0))
md_error(mddev, rdev);
break;
}
/* write it back and re-read */
start = d;
while (d != read_disk) {
if (d==0)
d = conf->raid_disks * 2;
d--;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
r1_sync_page_io(rdev, sect, s,
conf->tmppage, WRITE);
rdev_dec_pending(rdev, mddev);
} else
rcu_read_unlock();
}
d = start;
while (d != read_disk) {
char b[BDEVNAME_SIZE];
if (d==0)
d = conf->raid_disks * 2;
d--;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (r1_sync_page_io(rdev, sect, s,
conf->tmppage, READ)) {
atomic_add(s, &rdev->corrected_errors);
pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
mdname(mddev), s,
(unsigned long long)(sect +
rdev->data_offset),
bdevname(rdev->bdev, b));
}
rdev_dec_pending(rdev, mddev);
} else
rcu_read_unlock();
}
sectors -= s;
sect += s;
}
}
static int narrow_write_error(struct r1bio *r1_bio, int i)
{
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
struct md_rdev *rdev = conf->mirrors[i].rdev;
/* bio has the data to be written to device 'i' where
* we just recently had a write error.
* We repeatedly clone the bio and trim down to one block,
* then try the write. Where the write fails we record
* a bad block.
* It is conceivable that the bio doesn't exactly align with
* blocks. We must handle this somehow.
*
* We currently own a reference on the rdev.
*/
int block_sectors;
sector_t sector;
int sectors;
int sect_to_write = r1_bio->sectors;
int ok = 1;
if (rdev->badblocks.shift < 0)
return 0;
block_sectors = roundup(1 << rdev->badblocks.shift,
bdev_logical_block_size(rdev->bdev) >> 9);
sector = r1_bio->sector;
sectors = ((sector + block_sectors)
& ~(sector_t)(block_sectors - 1))
- sector;
while (sect_to_write) {
struct bio *wbio;
if (sectors > sect_to_write)
sectors = sect_to_write;
/* Write at 'sector' for 'sectors'*/
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
wbio = bio_clone_fast(r1_bio->behind_master_bio,
GFP_NOIO,
&mddev->bio_set);
} else {
wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO,
&mddev->bio_set);
}
bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
wbio->bi_iter.bi_sector = r1_bio->sector;
wbio->bi_iter.bi_size = r1_bio->sectors << 9;
bio_trim(wbio, sector - r1_bio->sector, sectors);
wbio->bi_iter.bi_sector += rdev->data_offset;
bio_set_dev(wbio, rdev->bdev);
if (submit_bio_wait(wbio) < 0)
/* failure! */
ok = rdev_set_badblocks(rdev, sector,
sectors, 0)
&& ok;
bio_put(wbio);
sect_to_write -= sectors;
sector += sectors;
sectors = block_sectors;
}
return ok;
}
static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
{
int m;
int s = r1_bio->sectors;
for (m = 0; m < conf->raid_disks * 2 ; m++) {
struct md_rdev *rdev = conf->mirrors[m].rdev;
struct bio *bio = r1_bio->bios[m];
if (bio->bi_end_io == NULL)
continue;
if (!bio->bi_status &&
test_bit(R1BIO_MadeGood, &r1_bio->state)) {
rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
}
if (bio->bi_status &&
test_bit(R1BIO_WriteError, &r1_bio->state)) {
if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
md_error(conf->mddev, rdev);
}
}
put_buf(r1_bio);
md_done_sync(conf->mddev, s, 1);
}
static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
{
int m, idx;
bool fail = false;
for (m = 0; m < conf->raid_disks * 2 ; m++)
if (r1_bio->bios[m] == IO_MADE_GOOD) {
struct md_rdev *rdev = conf->mirrors[m].rdev;
rdev_clear_badblocks(rdev,
r1_bio->sector,
r1_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
} else if (r1_bio->bios[m] != NULL) {
/* This drive got a write error. We need to
* narrow down and record precise write
* errors.
*/
fail = true;
if (!narrow_write_error(r1_bio, m)) {
md_error(conf->mddev,
conf->mirrors[m].rdev);
/* an I/O failed, we can't clear the bitmap */
set_bit(R1BIO_Degraded, &r1_bio->state);
}
rdev_dec_pending(conf->mirrors[m].rdev,
conf->mddev);
}
if (fail) {
spin_lock_irq(&conf->device_lock);
list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
idx = sector_to_idx(r1_bio->sector);
atomic_inc(&conf->nr_queued[idx]);
spin_unlock_irq(&conf->device_lock);
/*
* In case freeze_array() is waiting for condition
* get_unqueued_pending() == extra to be true.
*/
wake_up(&conf->wait_barrier);
md_wakeup_thread(conf->mddev->thread);
} else {
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
}
}
static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
{
struct mddev *mddev = conf->mddev;
struct bio *bio;
struct md_rdev *rdev;
clear_bit(R1BIO_ReadError, &r1_bio->state);
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
* We freeze all other IO, and try reading the block from
* other devices. When we find one, we re-write
* and check it that fixes the read error.
* This is all done synchronously while the array is
* frozen
*/
bio = r1_bio->bios[r1_bio->read_disk];
bio_put(bio);
r1_bio->bios[r1_bio->read_disk] = NULL;
rdev = conf->mirrors[r1_bio->read_disk].rdev;
if (mddev->ro == 0
&& !test_bit(FailFast, &rdev->flags)) {
freeze_array(conf, 1);
fix_read_error(conf, r1_bio->read_disk,
r1_bio->sector, r1_bio->sectors);
unfreeze_array(conf);
} else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
md_error(mddev, rdev);
} else {
r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
}
rdev_dec_pending(rdev, conf->mddev);
allow_barrier(conf, r1_bio->sector);
bio = r1_bio->master_bio;
/* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
r1_bio->state = 0;
raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
}
static void raid1d(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r1bio *r1_bio;
unsigned long flags;
struct r1conf *conf = mddev->private;
struct list_head *head = &conf->retry_list;
struct blk_plug plug;
int idx;
md_check_recovery(mddev);
if (!list_empty_careful(&conf->bio_end_io_list) &&
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
LIST_HEAD(tmp);
spin_lock_irqsave(&conf->device_lock, flags);
if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
list_splice_init(&conf->bio_end_io_list, &tmp);
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
r1_bio = list_first_entry(&tmp, struct r1bio,
retry_list);
list_del(&r1_bio->retry_list);
idx = sector_to_idx(r1_bio->sector);
atomic_dec(&conf->nr_queued[idx]);
if (mddev->degraded)
set_bit(R1BIO_Degraded, &r1_bio->state);
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
}
}
blk_start_plug(&plug);
for (;;) {
flush_pending_writes(conf);
spin_lock_irqsave(&conf->device_lock, flags);
if (list_empty(head)) {
spin_unlock_irqrestore(&conf->device_lock, flags);
break;
}
r1_bio = list_entry(head->prev, struct r1bio, retry_list);
list_del(head->prev);
idx = sector_to_idx(r1_bio->sector);
atomic_dec(&conf->nr_queued[idx]);
spin_unlock_irqrestore(&conf->device_lock, flags);
mddev = r1_bio->mddev;
conf = mddev->private;
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_sync_write_finished(conf, r1_bio);
else
sync_request_write(mddev, r1_bio);
} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_write_finished(conf, r1_bio);
else if (test_bit(R1BIO_ReadError, &r1_bio->state))
handle_read_error(conf, r1_bio);
else
WARN_ON_ONCE(1);
cond_resched();
if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
md_check_recovery(mddev);
}
blk_finish_plug(&plug);
}
static int init_resync(struct r1conf *conf)
{
int buffs;
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
BUG_ON(mempool_initialized(&conf->r1buf_pool));
return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
r1buf_pool_free, conf->poolinfo);
}
static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
{
struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
struct resync_pages *rps;
struct bio *bio;
int i;
for (i = conf->poolinfo->raid_disks; i--; ) {
bio = r1bio->bios[i];
rps = bio->bi_private;
bio_reset(bio);
bio->bi_private = rps;
}
r1bio->master_bio = NULL;
return r1bio;
}
/*
* perform a "sync" on one "block"
*
* We need to make sure that no normal I/O request - particularly write
* requests - conflict with active sync requests.
*
* This is achieved by tracking pending requests and a 'barrier' concept
* that can be installed to exclude normal IO requests.
*/
static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
struct bio *bio;
sector_t max_sector, nr_sectors;
int disk = -1;
int i;
int wonly = -1;
int write_targets = 0, read_targets = 0;
sector_t sync_blocks;
int still_degraded = 0;
int good_sectors = RESYNC_SECTORS;
int min_bad = 0; /* number of sectors that are bad in all devices */
int idx = sector_to_idx(sector_nr);
int page_idx = 0;
if (!mempool_initialized(&conf->r1buf_pool))
if (init_resync(conf))
return 0;
max_sector = mddev->dev_sectors;
if (sector_nr >= max_sector) {
/* If we aborted, we need to abort the
* sync on the 'current' bitmap chunk (there will
* only be one in raid1 resync.
* We can find the current addess in mddev->curr_resync
*/
if (mddev->curr_resync < max_sector) /* aborted */
md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
else /* completed sync */
conf->fullsync = 0;
md_bitmap_close_sync(mddev->bitmap);
close_sync(conf);
if (mddev_is_clustered(mddev)) {
conf->cluster_sync_low = 0;
conf->cluster_sync_high = 0;
}
return 0;
}
if (mddev->bitmap == NULL &&
mddev->recovery_cp == MaxSector &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
conf->fullsync == 0) {
*skipped = 1;
return max_sector - sector_nr;
}
/* before building a request, check if we can skip these blocks..
* This call the bitmap_start_sync doesn't actually record anything
*/
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* We can skip this block, and probably several more */
*skipped = 1;
return sync_blocks;
}
/*
* If there is non-resync activity waiting for a turn, then let it
* though before starting on this new sync request.
*/
if (atomic_read(&conf->nr_waiting[idx]))
schedule_timeout_uninterruptible(1);
/* we are incrementing sector_nr below. To be safe, we check against
* sector_nr + two times RESYNC_SECTORS
*/
md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
if (raise_barrier(conf, sector_nr))
return 0;
r1_bio = raid1_alloc_init_r1buf(conf);
rcu_read_lock();
/*
* If we get a correctably read error during resync or recovery,
* we might want to read from a different device. So we
* flag all drives that could conceivably be read from for READ,
* and any others (which will be non-In_sync devices) for WRITE.
* If a read fails, we try reading from something else for which READ
* is OK.
*/
r1_bio->mddev = mddev;
r1_bio->sector = sector_nr;
r1_bio->state = 0;
set_bit(R1BIO_IsSync, &r1_bio->state);
/* make sure good_sectors won't go across barrier unit boundary */
good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
for (i = 0; i < conf->raid_disks * 2; i++) {
struct md_rdev *rdev;
bio = r1_bio->bios[i];
rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags)) {
if (i < conf->raid_disks)
still_degraded = 1;
} else if (!test_bit(In_sync, &rdev->flags)) {
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
bio->bi_end_io = end_sync_write;
write_targets ++;
} else {
/* may need to read from here */
sector_t first_bad = MaxSector;
int bad_sectors;
if (is_badblock(rdev, sector_nr, good_sectors,
&first_bad, &bad_sectors)) {
if (first_bad > sector_nr)
good_sectors = first_bad - sector_nr;
else {
bad_sectors -= (sector_nr - first_bad);
if (min_bad == 0 ||
min_bad > bad_sectors)
min_bad = bad_sectors;
}
}
if (sector_nr < first_bad) {
if (test_bit(WriteMostly, &rdev->flags)) {
if (wonly < 0)
wonly = i;
} else {
if (disk < 0)
disk = i;
}
bio_set_op_attrs(bio, REQ_OP_READ, 0);
bio->bi_end_io = end_sync_read;
read_targets++;
} else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
!test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
/*
* The device is suitable for reading (InSync),
* but has bad block(s) here. Let's try to correct them,
* if we are doing resync or repair. Otherwise, leave
* this device alone for this sync request.
*/
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
bio->bi_end_io = end_sync_write;
write_targets++;
}
}
if (rdev && bio->bi_end_io) {
atomic_inc(&rdev->nr_pending);
bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
}
}
rcu_read_unlock();
if (disk < 0)
disk = wonly;
r1_bio->read_disk = disk;
if (read_targets == 0 && min_bad > 0) {
/* These sectors are bad on all InSync devices, so we
* need to mark them bad on all write targets
*/
int ok = 1;
for (i = 0 ; i < conf->raid_disks * 2 ; i++)
if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
ok = rdev_set_badblocks(rdev, sector_nr,
min_bad, 0
) && ok;
}
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
*skipped = 1;
put_buf(r1_bio);
if (!ok) {
/* Cannot record the badblocks, so need to
* abort the resync.
* If there are multiple read targets, could just
* fail the really bad ones ???
*/
conf->recovery_disabled = mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return 0;
} else
return min_bad;
}
if (min_bad > 0 && min_bad < good_sectors) {
/* only resync enough to reach the next bad->good
* transition */
good_sectors = min_bad;
}
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
/* extra read targets are also write targets */
write_targets += read_targets-1;
if (write_targets == 0 || read_targets == 0) {
/* There is nowhere to write, so all non-sync
* drives must be failed - so we are finished
*/
sector_t rv;
if (min_bad > 0)
max_sector = sector_nr + min_bad;
rv = max_sector - sector_nr;
*skipped = 1;
put_buf(r1_bio);
return rv;
}
if (max_sector > mddev->resync_max)
max_sector = mddev->resync_max; /* Don't do IO beyond here */
if (max_sector > sector_nr + good_sectors)
max_sector = sector_nr + good_sectors;
nr_sectors = 0;
sync_blocks = 0;
do {
struct page *page;
int len = PAGE_SIZE;
if (sector_nr + (len>>9) > max_sector)
len = (max_sector - sector_nr) << 9;
if (len == 0)
break;
if (sync_blocks == 0) {
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
&sync_blocks, still_degraded) &&
!conf->fullsync &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
break;
if ((len >> 9) > sync_blocks)
len = sync_blocks<<9;
}
for (i = 0 ; i < conf->raid_disks * 2; i++) {
struct resync_pages *rp;
bio = r1_bio->bios[i];
rp = get_resync_pages(bio);
if (bio->bi_end_io) {
page = resync_fetch_page(rp, page_idx);
/*
* won't fail because the vec table is big
* enough to hold all these pages
*/
bio_add_page(bio, page, len, 0);
}
}
nr_sectors += len>>9;
sector_nr += len>>9;
sync_blocks -= (len>>9);
} while (++page_idx < RESYNC_PAGES);
r1_bio->sectors = nr_sectors;
if (mddev_is_clustered(mddev) &&
conf->cluster_sync_high < sector_nr + nr_sectors) {
conf->cluster_sync_low = mddev->curr_resync_completed;
conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
/* Send resync message */
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
/* For a user-requested sync, we read all readable devices and do a
* compare
*/
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
atomic_set(&r1_bio->remaining, read_targets);
for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
bio = r1_bio->bios[i];
if (bio->bi_end_io == end_sync_read) {
read_targets--;
md_sync_acct_bio(bio, nr_sectors);
if (read_targets == 1)
bio->bi_opf &= ~MD_FAILFAST;
generic_make_request(bio);
}
}
} else {
atomic_set(&r1_bio->remaining, 1);
bio = r1_bio->bios[r1_bio->read_disk];
md_sync_acct_bio(bio, nr_sectors);
if (read_targets == 1)
bio->bi_opf &= ~MD_FAILFAST;
generic_make_request(bio);
}
return nr_sectors;
}
static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
if (sectors)
return sectors;
return mddev->dev_sectors;
}
static struct r1conf *setup_conf(struct mddev *mddev)
{
struct r1conf *conf;
int i;
struct raid1_info *disk;
struct md_rdev *rdev;
int err = -ENOMEM;
conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
if (!conf)
goto abort;
conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_pending)
goto abort;
conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_waiting)
goto abort;
conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_queued)
goto abort;
conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->barrier)
goto abort;
conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
mddev->raid_disks, 2),
GFP_KERNEL);
if (!conf->mirrors)
goto abort;
conf->tmppage = alloc_page(GFP_KERNEL);
if (!conf->tmppage)
goto abort;
conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
if (!conf->poolinfo)
goto abort;
conf->poolinfo->raid_disks = mddev->raid_disks * 2;
err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
rbio_pool_free, conf->poolinfo);
if (err)
goto abort;
err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
if (err)
goto abort;
conf->poolinfo->mddev = mddev;
err = -EINVAL;
spin_lock_init(&conf->device_lock);
rdev_for_each(rdev, mddev) {
int disk_idx = rdev->raid_disk;
if (disk_idx >= mddev->raid_disks
|| disk_idx < 0)
continue;
if (test_bit(Replacement, &rdev->flags))
disk = conf->mirrors + mddev->raid_disks + disk_idx;
else
disk = conf->mirrors + disk_idx;
if (disk->rdev)
goto abort;
disk->rdev = rdev;
disk->head_position = 0;
disk->seq_start = MaxSector;
}
conf->raid_disks = mddev->raid_disks;
conf->mddev = mddev;
INIT_LIST_HEAD(&conf->retry_list);
INIT_LIST_HEAD(&conf->bio_end_io_list);
spin_lock_init(&conf->resync_lock);
init_waitqueue_head(&conf->wait_barrier);
bio_list_init(&conf->pending_bio_list);
conf->pending_count = 0;
conf->recovery_disabled = mddev->recovery_disabled - 1;
err = -EIO;
for (i = 0; i < conf->raid_disks * 2; i++) {
disk = conf->mirrors + i;
if (i < conf->raid_disks &&
disk[conf->raid_disks].rdev) {
/* This slot has a replacement. */
if (!disk->rdev) {
/* No original, just make the replacement
* a recovering spare
*/
disk->rdev =
disk[conf->raid_disks].rdev;
disk[conf->raid_disks].rdev = NULL;
} else if (!test_bit(In_sync, &disk->rdev->flags))
/* Original is not in_sync - bad */
goto abort;
}
if (!disk->rdev ||
!test_bit(In_sync, &disk->rdev->flags)) {
disk->head_position = 0;
if (disk->rdev &&
(disk->rdev->saved_raid_disk < 0))
conf->fullsync = 1;
}
}
err = -ENOMEM;
conf->thread = md_register_thread(raid1d, mddev, "raid1");
if (!conf->thread)
goto abort;
return conf;
abort:
if (conf) {
mempool_exit(&conf->r1bio_pool);
kfree(conf->mirrors);
safe_put_page(conf->tmppage);
kfree(conf->poolinfo);
kfree(conf->nr_pending);
kfree(conf->nr_waiting);
kfree(conf->nr_queued);
kfree(conf->barrier);
bioset_exit(&conf->bio_split);
kfree(conf);
}
return ERR_PTR(err);
}
static void raid1_free(struct mddev *mddev, void *priv);
static int raid1_run(struct mddev *mddev)
{
struct r1conf *conf;
int i;
struct md_rdev *rdev;
int ret;
bool discard_supported = false;
if (mddev->level != 1) {
pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
mdname(mddev), mddev->level);
return -EIO;
}
if (mddev->reshape_position != MaxSector) {
pr_warn("md/raid1:%s: reshape_position set but not supported\n",
mdname(mddev));
return -EIO;
}
if (mddev_init_writes_pending(mddev) < 0)
return -ENOMEM;
/*
* copy the already verified devices into our private RAID1
* bookkeeping area. [whatever we allocate in run(),
* should be freed in raid1_free()]
*/
if (mddev->private == NULL)
conf = setup_conf(mddev);
else
conf = mddev->private;
if (IS_ERR(conf))
return PTR_ERR(conf);
if (mddev->queue) {
blk_queue_max_write_same_sectors(mddev->queue, 0);
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
}
rdev_for_each(rdev, mddev) {
if (!mddev->gendisk)
continue;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
discard_supported = true;
}
mddev->degraded = 0;
for (i = 0; i < conf->raid_disks; i++)
if (conf->mirrors[i].rdev == NULL ||
!test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
test_bit(Faulty, &conf->mirrors[i].rdev->flags))
mddev->degraded++;
/*
* RAID1 needs at least one disk in active
*/
if (conf->raid_disks - mddev->degraded < 1) {
ret = -EINVAL;
goto abort;
}
if (conf->raid_disks - mddev->degraded == 1)
mddev->recovery_cp = MaxSector;
if (mddev->recovery_cp != MaxSector)
pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
mdname(mddev));
pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
mdname(mddev), mddev->raid_disks - mddev->degraded,
mddev->raid_disks);
/*
* Ok, everything is just fine now
*/
mddev->thread = conf->thread;
conf->thread = NULL;
mddev->private = conf;
set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
if (mddev->queue) {
if (discard_supported)
blk_queue_flag_set(QUEUE_FLAG_DISCARD,
mddev->queue);
else
blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
mddev->queue);
}
ret = md_integrity_register(mddev);
if (ret) {
md_unregister_thread(&mddev->thread);
goto abort;
}
return 0;
abort:
raid1_free(mddev, conf);
return ret;
}
static void raid1_free(struct mddev *mddev, void *priv)
{
struct r1conf *conf = priv;
mempool_exit(&conf->r1bio_pool);
kfree(conf->mirrors);
safe_put_page(conf->tmppage);
kfree(conf->poolinfo);
kfree(conf->nr_pending);
kfree(conf->nr_waiting);
kfree(conf->nr_queued);
kfree(conf->barrier);
bioset_exit(&conf->bio_split);
kfree(conf);
}
static int raid1_resize(struct mddev *mddev, sector_t sectors)
{
/* no resync is happening, and there is enough space
* on all devices, so we can resize.
* We need to make sure resync covers any new space.
* If the array is shrinking we should possibly wait until
* any io in the removed space completes, but it hardly seems
* worth it.
*/
sector_t newsize = raid1_size(mddev, sectors, 0);
if (mddev->external_size &&
mddev->array_sectors > newsize)
return -EINVAL;
if (mddev->bitmap) {
int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
return ret;
}
md_set_array_sectors(mddev, newsize);
if (sectors > mddev->dev_sectors &&
mddev->recovery_cp > mddev->dev_sectors) {
mddev->recovery_cp = mddev->dev_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
mddev->dev_sectors = sectors;
mddev->resync_max_sectors = sectors;
return 0;
}
static int raid1_reshape(struct mddev *mddev)
{
/* We need to:
* 1/ resize the r1bio_pool
* 2/ resize conf->mirrors
*
* We allocate a new r1bio_pool if we can.
* Then raise a device barrier and wait until all IO stops.
* Then resize conf->mirrors and swap in the new r1bio pool.
*
* At the same time, we "pack" the devices so that all the missing
* devices have the higher raid_disk numbers.
*/
mempool_t newpool, oldpool;
struct pool_info *newpoolinfo;
struct raid1_info *newmirrors;
struct r1conf *conf = mddev->private;
int cnt, raid_disks;
unsigned long flags;
int d, d2;
int ret;
memset(&newpool, 0, sizeof(newpool));
memset(&oldpool, 0, sizeof(oldpool));
/* Cannot change chunk_size, layout, or level */
if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
mddev->layout != mddev->new_layout ||
mddev->level != mddev->new_level) {
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->new_layout = mddev->layout;
mddev->new_level = mddev->level;
return -EINVAL;
}
if (!mddev_is_clustered(mddev))
md_allow_write(mddev);
raid_disks = mddev->raid_disks + mddev->delta_disks;
if (raid_disks < conf->raid_disks) {
cnt=0;
for (d= 0; d < conf->raid_disks; d++)
if (conf->mirrors[d].rdev)
cnt++;
if (cnt > raid_disks)
return -EBUSY;
}
newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
if (!newpoolinfo)
return -ENOMEM;
newpoolinfo->mddev = mddev;
newpoolinfo->raid_disks = raid_disks * 2;
ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
rbio_pool_free, newpoolinfo);
if (ret) {
kfree(newpoolinfo);
return ret;
}
newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
raid_disks, 2),
GFP_KERNEL);
if (!newmirrors) {
kfree(newpoolinfo);
mempool_exit(&newpool);
return -ENOMEM;
}
freeze_array(conf, 0);
/* ok, everything is stopped */
oldpool = conf->r1bio_pool;
conf->r1bio_pool = newpool;
for (d = d2 = 0; d < conf->raid_disks; d++) {
struct md_rdev *rdev = conf->mirrors[d].rdev;
if (rdev && rdev->raid_disk != d2) {
sysfs_unlink_rdev(mddev, rdev);
rdev->raid_disk = d2;
sysfs_unlink_rdev(mddev, rdev);
if (sysfs_link_rdev(mddev, rdev))
pr_warn("md/raid1:%s: cannot register rd%d\n",
mdname(mddev), rdev->raid_disk);
}
if (rdev)
newmirrors[d2++].rdev = rdev;
}
kfree(conf->mirrors);
conf->mirrors = newmirrors;
kfree(conf->poolinfo);
conf->poolinfo = newpoolinfo;
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded += (raid_disks - conf->raid_disks);
spin_unlock_irqrestore(&conf->device_lock, flags);
conf->raid_disks = mddev->raid_disks = raid_disks;
mddev->delta_disks = 0;
unfreeze_array(conf);
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
mempool_exit(&oldpool);
return 0;
}
static void raid1_quiesce(struct mddev *mddev, int quiesce)
{
struct r1conf *conf = mddev->private;
if (quiesce)
freeze_array(conf, 0);
else
unfreeze_array(conf);
}
static void *raid1_takeover(struct mddev *mddev)
{
/* raid1 can take over:
* raid5 with 2 devices, any layout or chunk size
*/
if (mddev->level == 5 && mddev->raid_disks == 2) {
struct r1conf *conf;
mddev->new_level = 1;
mddev->new_layout = 0;
mddev->new_chunk_sectors = 0;
conf = setup_conf(mddev);
if (!IS_ERR(conf)) {
/* Array must appear to be quiesced */
conf->array_frozen = 1;
mddev_clear_unsupported_flags(mddev,
UNSUPPORTED_MDDEV_FLAGS);
}
return conf;
}
return ERR_PTR(-EINVAL);
}
static struct md_personality raid1_personality =
{
.name = "raid1",
.level = 1,
.owner = THIS_MODULE,
.make_request = raid1_make_request,
.run = raid1_run,
.free = raid1_free,
.status = raid1_status,
.error_handler = raid1_error,
.hot_add_disk = raid1_add_disk,
.hot_remove_disk= raid1_remove_disk,
.spare_active = raid1_spare_active,
.sync_request = raid1_sync_request,
.resize = raid1_resize,
.size = raid1_size,
.check_reshape = raid1_reshape,
.quiesce = raid1_quiesce,
.takeover = raid1_takeover,
.congested = raid1_congested,
};
static int __init raid_init(void)
{
return register_md_personality(&raid1_personality);
}
static void raid_exit(void)
{
unregister_md_personality(&raid1_personality);
}
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
MODULE_ALIAS("md-personality-3"); /* RAID1 */
MODULE_ALIAS("md-raid1");
MODULE_ALIAS("md-level-1");
module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
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