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linux/drivers/md/raid1.c
Christoph Hellwig 176df894d7 md: add a mddev_is_dm helper 
Add a helper to check for a DM-mapped MD device instead of using
the obfuscated ->gendisk or ->queue NULL checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed--by: Song Liu <song@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240303140150.5435-4-hch@lst.de
2024-03-06 08:59:53 -08:00

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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 RAID_1_10_NAME "raid1"
#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(RESYNC_PAGES, gfp_flags);
if (!bio)
goto out_free_bio;
bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
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_uninit(r1_bio->bios[j]);
kfree(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_uninit(r1bio->bios[i]);
kfree(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;
sector_t sector = r1_bio->sector;
/* 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);
}
free_r1bio(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, sector);
}
/*
* 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:
*/
pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
mdname(conf->mddev),
rdev->bdev,
(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.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_WriteError, &r1_bio->state);
else {
/* Fail the request */
set_bit(R1BIO_Degraded, &r1_bio->state);
/* 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.
*/
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 (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->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;
}
static void update_read_sectors(struct r1conf *conf, int disk,
sector_t this_sector, int len)
{
struct raid1_info *info = &conf->mirrors[disk];
atomic_inc(&info->rdev->nr_pending);
if (info->next_seq_sect != this_sector)
info->seq_start = this_sector;
info->next_seq_sect = this_sector + len;
}
static int choose_first_rdev(struct r1conf *conf, struct r1bio *r1_bio,
int *max_sectors)
{
sector_t this_sector = r1_bio->sector;
int len = r1_bio->sectors;
int disk;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
struct md_rdev *rdev;
int read_len;
if (r1_bio->bios[disk] == IO_BLOCKED)
continue;
rdev = conf->mirrors[disk].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags))
continue;
/* choose the first disk even if it has some bad blocks. */
read_len = raid1_check_read_range(rdev, this_sector, &len);
if (read_len > 0) {
update_read_sectors(conf, disk, this_sector, read_len);
*max_sectors = read_len;
return disk;
}
}
return -1;
}
static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio,
int *max_sectors)
{
sector_t this_sector = r1_bio->sector;
int best_disk = -1;
int best_len = 0;
int disk;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
struct md_rdev *rdev;
int len;
int read_len;
if (r1_bio->bios[disk] == IO_BLOCKED)
continue;
rdev = conf->mirrors[disk].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags) ||
test_bit(WriteMostly, &rdev->flags))
continue;
/* keep track of the disk with the most readable sectors. */
len = r1_bio->sectors;
read_len = raid1_check_read_range(rdev, this_sector, &len);
if (read_len > best_len) {
best_disk = disk;
best_len = read_len;
}
}
if (best_disk != -1) {
*max_sectors = best_len;
update_read_sectors(conf, best_disk, this_sector, best_len);
}
return best_disk;
}
static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio,
int *max_sectors)
{
sector_t this_sector = r1_bio->sector;
int bb_disk = -1;
int bb_read_len = 0;
int disk;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
struct md_rdev *rdev;
int len;
int read_len;
if (r1_bio->bios[disk] == IO_BLOCKED)
continue;
rdev = conf->mirrors[disk].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags) ||
!test_bit(WriteMostly, &rdev->flags))
continue;
/* there are no bad blocks, we can use this disk */
len = r1_bio->sectors;
read_len = raid1_check_read_range(rdev, this_sector, &len);
if (read_len == r1_bio->sectors) {
update_read_sectors(conf, disk, this_sector, read_len);
return disk;
}
/*
* there are partial bad blocks, choose the rdev with largest
* read length.
*/
if (read_len > bb_read_len) {
bb_disk = disk;
bb_read_len = read_len;
}
}
if (bb_disk != -1) {
*max_sectors = bb_read_len;
update_read_sectors(conf, bb_disk, this_sector, bb_read_len);
}
return bb_disk;
}
static bool is_sequential(struct r1conf *conf, int disk, struct r1bio *r1_bio)
{
/* TODO: address issues with this check and concurrency. */
return conf->mirrors[disk].next_seq_sect == r1_bio->sector ||
conf->mirrors[disk].head_position == r1_bio->sector;
}
/*
* If buffered sequential IO size exceeds optimal iosize, check if there is idle
* disk. If yes, choose the idle disk.
*/
static bool should_choose_next(struct r1conf *conf, int disk)
{
struct raid1_info *mirror = &conf->mirrors[disk];
int opt_iosize;
if (!test_bit(Nonrot, &mirror->rdev->flags))
return false;
opt_iosize = bdev_io_opt(mirror->rdev->bdev) >> 9;
return opt_iosize > 0 && mirror->seq_start != MaxSector &&
mirror->next_seq_sect > opt_iosize &&
mirror->next_seq_sect - opt_iosize >= mirror->seq_start;
}
static bool rdev_readable(struct md_rdev *rdev, struct r1bio *r1_bio)
{
if (!rdev || test_bit(Faulty, &rdev->flags))
return false;
/* still in recovery */
if (!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < r1_bio->sector + r1_bio->sectors)
return false;
/* don't read from slow disk unless have to */
if (test_bit(WriteMostly, &rdev->flags))
return false;
/* don't split IO for bad blocks unless have to */
if (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors))
return false;
return true;
}
struct read_balance_ctl {
sector_t closest_dist;
int closest_dist_disk;
int min_pending;
int min_pending_disk;
int sequential_disk;
int readable_disks;
};
static int choose_best_rdev(struct r1conf *conf, struct r1bio *r1_bio)
{
int disk;
struct read_balance_ctl ctl = {
.closest_dist_disk = -1,
.closest_dist = MaxSector,
.min_pending_disk = -1,
.min_pending = UINT_MAX,
.sequential_disk = -1,
};
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
struct md_rdev *rdev;
sector_t dist;
unsigned int pending;
if (r1_bio->bios[disk] == IO_BLOCKED)
continue;
rdev = conf->mirrors[disk].rdev;
if (!rdev_readable(rdev, r1_bio))
continue;
/* At least two disks to choose from so failfast is OK */
if (ctl.readable_disks++ == 1)
set_bit(R1BIO_FailFast, &r1_bio->state);
pending = atomic_read(&rdev->nr_pending);
dist = abs(r1_bio->sector - conf->mirrors[disk].head_position);
/* Don't change to another disk for sequential reads */
if (is_sequential(conf, disk, r1_bio)) {
if (!should_choose_next(conf, disk))
return disk;
/*
* Add 'pending' to avoid choosing this disk if
* there is other idle disk.
*/
pending++;
/*
* If there is no other idle disk, this disk
* will be chosen.
*/
ctl.sequential_disk = disk;
}
if (ctl.min_pending > pending) {
ctl.min_pending = pending;
ctl.min_pending_disk = disk;
}
if (ctl.closest_dist > dist) {
ctl.closest_dist = dist;
ctl.closest_dist_disk = disk;
}
}
/*
* sequential IO size exceeds optimal iosize, however, there is no other
* idle disk, so choose the sequential disk.
*/
if (ctl.sequential_disk != -1 && ctl.min_pending != 0)
return ctl.sequential_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 (ctl.min_pending_disk != -1 &&
(READ_ONCE(conf->nonrot_disks) || ctl.min_pending == 0))
return ctl.min_pending_disk;
else
return ctl.closest_dist_disk;
}
/*
* This routine returns the disk from which the requested read should be done.
*
* 1) If resync is in progress, find the first usable disk and use it even if it
* has some bad blocks.
*
* 2) Now that there is no resync, loop through all disks and skipping slow
* disks and disks with bad blocks for now. Only pay attention to key disk
* choice.
*
* 3) If we've made it this far, now look for disks with bad blocks and choose
* the one with most number of sectors.
*
* 4) If we are all the way at the end, we have no choice but to use a disk even
* if it is write mostly.
*
* 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)
{
int disk;
clear_bit(R1BIO_FailFast, &r1_bio->state);
if (raid1_should_read_first(conf->mddev, r1_bio->sector,
r1_bio->sectors))
return choose_first_rdev(conf, r1_bio, max_sectors);
disk = choose_best_rdev(conf, r1_bio);
if (disk >= 0) {
*max_sectors = r1_bio->sectors;
update_read_sectors(conf, disk, r1_bio->sector,
r1_bio->sectors);
return disk;
}
/*
* If we are here it means we didn't find a perfectly good disk so
* now spend a bit more time trying to find one with the most good
* sectors.
*/
disk = choose_bb_rdev(conf, r1_bio, max_sectors);
if (disk >= 0)
return disk;
return choose_slow_rdev(conf, r1_bio, max_sectors);
}
static void wake_up_barrier(struct r1conf *conf)
{
if (wq_has_sleeper(&conf->wait_barrier))
wake_up(&conf->wait_barrier);
}
static void flush_bio_list(struct r1conf *conf, struct bio *bio)
{
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up_barrier(conf);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
raid1_submit_write(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);
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 bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
{
bool ret = true;
/*
* 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 ret;
/*
* 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_barrier(conf);
/* Wait for the barrier in same barrier unit bucket to drop. */
/* Return false when nowait flag is set */
if (nowait) {
ret = false;
} else {
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);
return ret;
}
static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
{
int idx = sector_to_idx(sector_nr);
bool ret = true;
/*
* 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 ret;
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_barrier(conf);
/* Wait for array to be unfrozen */
/* Return false when nowait flag is set */
if (nowait) {
/* Return false when nowait flag is set */
ret = false;
} else {
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);
return ret;
}
static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
{
int idx = sector_to_idx(sector_nr);
return _wait_barrier(conf, idx, nowait);
}
static void _allow_barrier(struct r1conf *conf, int idx)
{
atomic_dec(&conf->nr_pending[idx]);
wake_up_barrier(conf);
}
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;
mddev_add_trace_msg(conf->mddev, "raid1 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_bioset(NULL, vcnt, 0, GFP_NOIO,
&r1_bio->mddev->bio_set);
/* discard op, we don't support writezero/writesame yet */
if (!bio_has_data(bio)) {
behind_bio->bi_iter.bi_size = size;
goto skip_copy;
}
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;
if (!bio_add_page(behind_bio, page, len, 0)) {
put_page(page);
goto free_pages;
}
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);
}
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) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
spin_unlock_irq(&conf->device_lock);
wake_up_barrier(conf);
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 enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
int rdisk;
bool r1bio_existed = !!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 (r1bio_existed) {
/* Need to get the block device name carefully */
struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
if (rdev)
snprintf(b, sizeof(b), "%pg", rdev->bdev);
else
strcpy(b, "???");
}
/*
* Still need barrier for READ in case that whole
* array is frozen.
*/
if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return;
}
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 (r1bio_existed) {
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 (r1bio_existed)
pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
mdname(mddev),
(unsigned long long)r1_bio->sector,
mirror->rdev->bdev);
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'
*/
mddev_add_trace_msg(mddev, "raid1 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);
submit_bio_noacct(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
r1_bio->read_disk = rdisk;
if (!r1bio_existed) {
md_account_bio(mddev, &bio);
r1_bio->master_bio = bio;
}
read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
&mddev->bio_set);
r1_bio->bios[rdisk] = read_bio;
read_bio->bi_iter.bi_sector = r1_bio->sector +
mirror->rdev->data_offset;
read_bio->bi_end_io = raid1_end_read_request;
read_bio->bi_opf = 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;
mddev_trace_remap(mddev, read_bio, r1_bio->sector);
submit_bio_noacct(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;
int first_clone;
int max_sectors;
bool write_behind = false;
bool is_discard = (bio_op(bio) == REQ_OP_DISCARD);
if (mddev_is_clustered(mddev) &&
md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector, bio_end_sector(bio))) {
DEFINE_WAIT(w);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
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.
*/
if (!wait_barrier(conf, bio->bi_iter.bi_sector,
bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return;
}
retry_write:
r1_bio = alloc_r1bio(mddev, bio);
r1_bio->sectors = max_write_sectors;
/* 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;
blocked_rdev = NULL;
max_sectors = r1_bio->sectors;
for (i = 0; i < disks; i++) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
/*
* The write-behind io is only attempted on drives marked as
* write-mostly, which means we could allocate write behind
* bio later.
*/
if (!is_discard && rdev && test_bit(WriteMostly, &rdev->flags))
write_behind = true;
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;
}
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);
free_r1bio(r1_bio);
allow_barrier(conf, bio->bi_iter.bi_sector);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
mddev_add_trace_msg(mddev, "raid1 wait rdev %d blocked",
blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf, bio->bi_iter.bi_sector, false);
goto retry_write;
}
/*
* When using a bitmap, we may call alloc_behind_master_bio below.
* alloc_behind_master_bio allocates a copy of the data payload a page
* at a time and thus needs a new bio that can fit the whole payload
* this bio in page sized chunks.
*/
if (write_behind && bitmap)
max_sectors = min_t(int, max_sectors,
BIO_MAX_VECS * (PAGE_SIZE >> 9));
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
md_account_bio(mddev, &bio);
r1_bio->master_bio = bio;
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 && write_behind &&
(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_alloc_clone(rdev->bdev,
r1_bio->behind_master_bio,
GFP_NOIO, &mddev->bio_set);
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 {
mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
&mddev->bio_set);
if (mddev->serialize_policy)
wait_for_serialization(rdev, r1_bio);
}
r1_bio->bios[i] = mbio;
mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
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, &rdev->flags) &&
!test_bit(WriteMostly, &rdev->flags) &&
conf->raid_disks - mddev->degraded > 1)
mbio->bi_opf |= MD_FAILFAST;
mbio->bi_private = r1_bio;
atomic_inc(&r1_bio->remaining);
mddev_trace_remap(mddev, mbio, r1_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void *)rdev;
if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) {
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
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_barrier(conf);
}
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;
lockdep_assert_held(&mddev->lock);
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = READ_ONCE(conf->mirrors[i].rdev);
seq_printf(seq, "%s",
rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
seq_printf(seq, "]");
}
/**
* raid1_error() - RAID1 error handler.
* @mddev: affected md device.
* @rdev: member device to fail.
*
* The routine acknowledges &rdev failure and determines new @mddev state.
* If it failed, then:
* - &MD_BROKEN flag is set in &mddev->flags.
* - recovery is disabled.
* Otherwise, it must be degraded:
* - recovery is interrupted.
* - &mddev->degraded is bumped.
*
* @rdev is marked as &Faulty excluding case when array is failed and
* &mddev->fail_last_dev is off.
*/
static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) &&
(conf->raid_disks - mddev->degraded) == 1) {
set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
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 %pg, disabling device.\n"
"md/raid1:%s: Operation continuing on %d devices.\n",
mdname(mddev), rdev->bdev,
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);
lockdep_assert_held(&conf->mddev->reconfig_mutex);
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
if (rdev)
pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
i, !test_bit(In_sync, &rdev->flags),
!test_bit(Faulty, &rdev->flags),
rdev->bdev);
}
}
static void close_sync(struct r1conf *conf)
{
int idx;
for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
_wait_barrier(conf, idx, false);
_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 bool raid1_add_conf(struct r1conf *conf, struct md_rdev *rdev, int disk,
bool replacement)
{
struct raid1_info *info = conf->mirrors + disk;
if (replacement)
info += conf->raid_disks;
if (info->rdev)
return false;
if (bdev_nonrot(rdev->bdev)) {
set_bit(Nonrot, &rdev->flags);
WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks + 1);
}
rdev->raid_disk = disk;
info->head_position = 0;
info->seq_start = MaxSector;
WRITE_ONCE(info->rdev, rdev);
return true;
}
static bool raid1_remove_conf(struct r1conf *conf, int disk)
{
struct raid1_info *info = conf->mirrors + disk;
struct md_rdev *rdev = info->rdev;
if (!rdev || test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending))
return false;
/* Only remove non-faulty devices if recovery is not possible. */
if (!test_bit(Faulty, &rdev->flags) &&
rdev->mddev->recovery_disabled != conf->recovery_disabled &&
rdev->mddev->degraded < conf->raid_disks)
return false;
if (test_and_clear_bit(Nonrot, &rdev->flags))
WRITE_ONCE(conf->nonrot_disks, conf->nonrot_disks - 1);
WRITE_ONCE(info->rdev, NULL);
return true;
}
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
int err = -EEXIST;
int mirror = 0, repl_slot = -1;
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_is_dm(mddev))
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
raid1_add_conf(conf, rdev, mirror, false);
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;
break;
}
if (test_bit(WantReplacement, &p->rdev->flags) &&
p[conf->raid_disks].rdev == NULL && repl_slot < 0)
repl_slot = mirror;
}
if (err && repl_slot >= 0) {
/* Add this device as a replacement */
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
raid1_add_conf(conf, rdev, repl_slot, true);
err = 0;
conf->fullsync = 1;
}
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 (unlikely(number >= conf->raid_disks))
goto abort;
if (rdev != p->rdev) {
number += conf->raid_disks;
p = conf->mirrors + number;
}
print_conf(conf);
if (rdev == p->rdev) {
if (!raid1_remove_conf(conf, number)) {
err = -EBUSY;
goto abort;
}
if (number < conf->raid_disks &&
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);
WRITE_ONCE(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;
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 (rdev_has_badblock(rdev, r1_bio->sector, r1_bio->sectors) &&
!rdev_has_badblock(conf->mirrors[r1_bio->read_disk].rdev,
r1_bio->sector, r1_bio->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, blk_opf_t rw)
{
if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
/* success */
return 1;
if (rw == REQ_OP_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, false)) {
success = 1;
break;
}
}
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (!success && d != r1_bio->read_disk);
if (!success) {
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: %pg: unrecoverable I/O read error for block %llu\n",
mdname(mddev), bio->bi_bdev,
(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],
REQ_OP_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],
REQ_OP_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, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
b->bi_status = status;
b->bi_iter.bi_sector = r1_bio->sector +
conf->mirrors[i].rdev->data_offset;
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;
}
wbio->bi_opf = REQ_OP_WRITE;
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));
submit_bio_noacct(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, struct r1bio *r1_bio)
{
sector_t sect = r1_bio->sector;
int sectors = r1_bio->sectors;
int read_disk = r1_bio->read_disk;
struct mddev *mddev = conf->mddev;
struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
if (exceed_read_errors(mddev, rdev)) {
r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
return;
}
while(sectors) {
int s = sectors;
int d = read_disk;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
rdev = conf->mirrors[d].rdev;
if (rdev &&
(test_bit(In_sync, &rdev->flags) ||
(!test_bit(Faulty, &rdev->flags) &&
rdev->recovery_offset >= sect + s)) &&
rdev_has_badblock(rdev, sect, s) == 0) {
atomic_inc(&rdev->nr_pending);
if (sync_page_io(rdev, sect, s<<9,
conf->tmppage, REQ_OP_READ, false))
success = 1;
rdev_dec_pending(rdev, mddev);
if (success)
break;
}
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (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--;
rdev = conf->mirrors[d].rdev;
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
r1_sync_page_io(rdev, sect, s,
conf->tmppage, REQ_OP_WRITE);
rdev_dec_pending(rdev, mddev);
}
}
d = start;
while (d != read_disk) {
if (d==0)
d = conf->raid_disks * 2;
d--;
rdev = conf->mirrors[d].rdev;
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
if (r1_sync_page_io(rdev, sect, s,
conf->tmppage, REQ_OP_READ)) {
atomic_add(s, &rdev->corrected_errors);
pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(sect +
rdev->data_offset),
rdev->bdev);
}
rdev_dec_pending(rdev, mddev);
}
}
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_alloc_clone(rdev->bdev,
r1_bio->behind_master_bio,
GFP_NOIO, &mddev->bio_set);
} else {
wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
GFP_NOIO, &mddev->bio_set);
}
wbio->bi_opf = REQ_OP_WRITE;
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;
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;
sector_t sector;
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);
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);
sector = 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);
allow_barrier(conf, sector);
}
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, NULL, 0);
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);
/*
* 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 = 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->bi_opf = REQ_OP_WRITE;
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->bi_opf = REQ_OP_READ;
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->bi_opf = REQ_OP_WRITE;
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;
}
}
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;
submit_bio_noacct(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;
submit_bio_noacct(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);
conf->raid_disks = mddev->raid_disks;
rdev_for_each(rdev, mddev) {
int disk_idx = rdev->raid_disk;
if (disk_idx >= conf->raid_disks || disk_idx < 0)
continue;
if (!raid1_add_conf(conf, rdev, disk_idx,
test_bit(Replacement, &rdev->flags)))
goto abort;
}
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->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;
rcu_assign_pointer(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;
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;
}
/*
* 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_is_dm(mddev)) {
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
rdev_for_each(rdev, mddev)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
}
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) {
md_unregister_thread(mddev, &conf->thread);
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
*/
rcu_assign_pointer(mddev->thread, conf->thread);
rcu_assign_pointer(conf->thread, NULL);
mddev->private = conf;
set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
ret = md_integrity_register(mddev);
if (ret) {
md_unregister_thread(mddev, &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,
};
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");
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