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android-kvm / linux / 3df9427f351a9cb8aee0eea13d185f0d78340a70 / . / drivers / md / raid10.c
blob: 2a9c4ee982e023f15100571d2abcfa7f72f9cf5f [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* raid10.c : Multiple Devices driver for Linux
*
* Copyright (C) 2000-2004 Neil Brown
*
* RAID-10 support for md.
*
* Base on code in raid1.c. See raid1.c for further copyright information.
*/
#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/kthread.h>
#include <linux/raid/md_p.h>
#include <trace/events/block.h>
#include "md.h"
#define RAID_1_10_NAME "raid10"
#include "raid10.h"
#include "raid0.h"
#include "md-bitmap.h"
/*
* RAID10 provides a combination of RAID0 and RAID1 functionality.
* The layout of data is defined by
* chunk_size
* raid_disks
* near_copies (stored in low byte of layout)
* far_copies (stored in second byte of layout)
* far_offset (stored in bit 16 of layout )
* use_far_sets (stored in bit 17 of layout )
* use_far_sets_bugfixed (stored in bit 18 of layout )
*
* The data to be stored is divided into chunks using chunksize. Each device
* is divided into far_copies sections. In each section, chunks are laid out
* in a style similar to raid0, but near_copies copies of each chunk is stored
* (each on a different drive). The starting device for each section is offset
* near_copies from the starting device of the previous section. Thus there
* are (near_copies * far_copies) of each chunk, and each is on a different
* drive. near_copies and far_copies must be at least one, and their product
* is at most raid_disks.
*
* If far_offset is true, then the far_copies are handled a bit differently.
* The copies are still in different stripes, but instead of being very far
* apart on disk, there are adjacent stripes.
*
* The far and offset algorithms are handled slightly differently if
* 'use_far_sets' is true. In this case, the array's devices are grouped into
* sets that are (near_copies * far_copies) in size. The far copied stripes
* are still shifted by 'near_copies' devices, but this shifting stays confined
* to the set rather than the entire array. This is done to improve the number
* of device combinations that can fail without causing the array to fail.
* Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk
* on a device):
* A B C D A B C D E
* ... ...
* D A B C E A B C D
* Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s):
* [A B] [C D] [A B] [C D E]
* |...| |...| |...| | ... |
* [B A] [D C] [B A] [E C D]
*/
static void allow_barrier(struct r10conf *conf);
static void lower_barrier(struct r10conf *conf);
static int _enough(struct r10conf *conf, int previous, int ignore);
static int enough(struct r10conf *conf, int ignore);
static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
int *skipped);
static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio);
static void end_reshape_write(struct bio *bio);
static void end_reshape(struct r10conf *conf);
#include "raid1-10.c"
#define NULL_CMD
#define cmd_before(conf, cmd) \
do { \
write_sequnlock_irq(&(conf)->resync_lock); \
cmd; \
} while (0)
#define cmd_after(conf) write_seqlock_irq(&(conf)->resync_lock)
#define wait_event_barrier_cmd(conf, cond, cmd) \
wait_event_cmd((conf)->wait_barrier, cond, cmd_before(conf, cmd), \
cmd_after(conf))
#define wait_event_barrier(conf, cond) \
wait_event_barrier_cmd(conf, cond, NULL_CMD)
/*
* for resync bio, r10bio pointer can be retrieved from the per-bio
* 'struct resync_pages'.
*/
static inline struct r10bio *get_resync_r10bio(struct bio *bio)
{
return get_resync_pages(bio)->raid_bio;
}
static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
{
struct r10conf *conf = data;
int size = offsetof(struct r10bio, devs[conf->geo.raid_disks]);
/* allocate a r10bio with room for raid_disks entries in the
* bios array */
return kzalloc(size, gfp_flags);
}
#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
/* amount of memory to reserve for resync requests */
#define RESYNC_WINDOW (1024*1024)
/* maximum number of concurrent requests, memory permitting */
#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
#define CLUSTER_RESYNC_WINDOW (32 * RESYNC_WINDOW)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
/*
* When performing a resync, we need to read and compare, so
* we need as many pages are there are copies.
* When performing a recovery, we need 2 bios, one for read,
* one for write (we recover only one drive per r10buf)
*
*/
static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
{
struct r10conf *conf = data;
struct r10bio *r10_bio;
struct bio *bio;
int j;
int nalloc, nalloc_rp;
struct resync_pages *rps;
r10_bio = r10bio_pool_alloc(gfp_flags, conf);
if (!r10_bio)
return NULL;
if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
nalloc = conf->copies; /* resync */
else
nalloc = 2; /* recovery */
/* allocate once for all bios */
if (!conf->have_replacement)
nalloc_rp = nalloc;
else
nalloc_rp = nalloc * 2;
rps = kmalloc_array(nalloc_rp, sizeof(struct resync_pages), gfp_flags);
if (!rps)
goto out_free_r10bio;
/*
* Allocate bios.
*/
for (j = nalloc ; 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);
r10_bio->devs[j].bio = bio;
if (!conf->have_replacement)
continue;
bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
if (!bio)
goto out_free_bio;
bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
r10_bio->devs[j].repl_bio = bio;
}
/*
* Allocate RESYNC_PAGES data pages and attach them
* where needed.
*/
for (j = 0; j < nalloc; j++) {
struct bio *rbio = r10_bio->devs[j].repl_bio;
struct resync_pages *rp, *rp_repl;
rp = &rps[j];
if (rbio)
rp_repl = &rps[nalloc + j];
bio = r10_bio->devs[j].bio;
if (!j || test_bit(MD_RECOVERY_SYNC,
&conf->mddev->recovery)) {
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 = r10_bio;
bio->bi_private = rp;
if (rbio) {
memcpy(rp_repl, rp, sizeof(*rp));
rbio->bi_private = rp_repl;
}
}
return r10_bio;
out_free_pages:
while (--j >= 0)
resync_free_pages(&rps[j]);
j = 0;
out_free_bio:
for ( ; j < nalloc; j++) {
if (r10_bio->devs[j].bio)
bio_uninit(r10_bio->devs[j].bio);
kfree(r10_bio->devs[j].bio);
if (r10_bio->devs[j].repl_bio)
bio_uninit(r10_bio->devs[j].repl_bio);
kfree(r10_bio->devs[j].repl_bio);
}
kfree(rps);
out_free_r10bio:
rbio_pool_free(r10_bio, conf);
return NULL;
}
static void r10buf_pool_free(void *__r10_bio, void *data)
{
struct r10conf *conf = data;
struct r10bio *r10bio = __r10_bio;
int j;
struct resync_pages *rp = NULL;
for (j = conf->copies; j--; ) {
struct bio *bio = r10bio->devs[j].bio;
if (bio) {
rp = get_resync_pages(bio);
resync_free_pages(rp);
bio_uninit(bio);
kfree(bio);
}
bio = r10bio->devs[j].repl_bio;
if (bio) {
bio_uninit(bio);
kfree(bio);
}
}
/* resync pages array stored in the 1st bio's .bi_private */
kfree(rp);
rbio_pool_free(r10bio, conf);
}
static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
{
int i;
for (i = 0; i < conf->geo.raid_disks; i++) {
struct bio **bio = & r10_bio->devs[i].bio;
if (!BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
bio = &r10_bio->devs[i].repl_bio;
if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
}
}
static void free_r10bio(struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
put_all_bios(conf, r10_bio);
mempool_free(r10_bio, &conf->r10bio_pool);
}
static void put_buf(struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
mempool_free(r10_bio, &conf->r10buf_pool);
lower_barrier(conf);
}
static void wake_up_barrier(struct r10conf *conf)
{
if (wq_has_sleeper(&conf->wait_barrier))
wake_up(&conf->wait_barrier);
}
static void reschedule_retry(struct r10bio *r10_bio)
{
unsigned long flags;
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&r10_bio->retry_list, &conf->retry_list);
conf->nr_queued ++;
spin_unlock_irqrestore(&conf->device_lock, flags);
/* wake up frozen array... */
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 raid_end_bio_io(struct r10bio *r10_bio)
{
struct bio *bio = r10_bio->master_bio;
struct r10conf *conf = r10_bio->mddev->private;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
/*
* Wake up any possible resync thread that waits for the device
* to go idle.
*/
allow_barrier(conf);
free_r10bio(r10_bio);
}
/*
* Update disk head position estimator based on IRQ completion info.
*/
static inline void update_head_pos(int slot, struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
conf->mirrors[r10_bio->devs[slot].devnum].head_position =
r10_bio->devs[slot].addr + (r10_bio->sectors);
}
/*
* Find the disk number which triggered given bio
*/
static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
struct bio *bio, int *slotp, int *replp)
{
int slot;
int repl = 0;
for (slot = 0; slot < conf->geo.raid_disks; slot++) {
if (r10_bio->devs[slot].bio == bio)
break;
if (r10_bio->devs[slot].repl_bio == bio) {
repl = 1;
break;
}
}
update_head_pos(slot, r10_bio);
if (slotp)
*slotp = slot;
if (replp)
*replp = repl;
return r10_bio->devs[slot].devnum;
}
static void raid10_end_read_request(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r10bio *r10_bio = bio->bi_private;
int slot;
struct md_rdev *rdev;
struct r10conf *conf = r10_bio->mddev->private;
slot = r10_bio->read_slot;
rdev = r10_bio->devs[slot].rdev;
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
update_head_pos(slot, r10_bio);
if (uptodate) {
/*
* Set R10BIO_Uptodate in our master bio, so that
* we will return a good error code 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.
*/
set_bit(R10BIO_Uptodate, &r10_bio->state);
} else {
/* If all other devices that store this block 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"
*/
if (!_enough(conf, test_bit(R10BIO_Previous, &r10_bio->state),
rdev->raid_disk))
uptodate = 1;
}
if (uptodate) {
raid_end_bio_io(r10_bio);
rdev_dec_pending(rdev, conf->mddev);
} else {
/*
* oops, read error - keep the refcount on the rdev
*/
pr_err_ratelimited("md/raid10:%s: %pg: rescheduling sector %llu\n",
mdname(conf->mddev),
rdev->bdev,
(unsigned long long)r10_bio->sector);
set_bit(R10BIO_ReadError, &r10_bio->state);
reschedule_retry(r10_bio);
}
}
static void close_write(struct r10bio *r10_bio)
{
/* clear the bitmap if all writes complete successfully */
md_bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
r10_bio->sectors,
!test_bit(R10BIO_Degraded, &r10_bio->state),
0);
md_write_end(r10_bio->mddev);
}
static void one_write_done(struct r10bio *r10_bio)
{
if (atomic_dec_and_test(&r10_bio->remaining)) {
if (test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else {
close_write(r10_bio);
if (test_bit(R10BIO_MadeGood, &r10_bio->state))
reschedule_retry(r10_bio);
else
raid_end_bio_io(r10_bio);
}
}
}
static void raid10_end_write_request(struct bio *bio)
{
struct r10bio *r10_bio = bio->bi_private;
int dev;
int dec_rdev = 1;
struct r10conf *conf = r10_bio->mddev->private;
int slot, repl;
struct md_rdev *rdev = NULL;
struct bio *to_put = NULL;
bool discard_error;
discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[dev].replacement;
if (!rdev) {
smp_rmb();
repl = 0;
rdev = conf->mirrors[dev].rdev;
}
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
if (bio->bi_status && !discard_error) {
if (repl)
/* Never record new bad blocks to replacement,
* just fail it.
*/
md_error(rdev->mddev, rdev);
else {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
dec_rdev = 0;
if (test_bit(FailFast, &rdev->flags) &&
(bio->bi_opf & MD_FAILFAST)) {
md_error(rdev->mddev, rdev);
}
/*
* When the device is faulty, it is not necessary to
* handle write error.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R10BIO_WriteError, &r10_bio->state);
else {
/* Fail the request */
set_bit(R10BIO_Degraded, &r10_bio->state);
r10_bio->devs[slot].bio = NULL;
to_put = bio;
dec_rdev = 1;
}
}
} else {
/*
* Set R10BIO_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.
*
* Do not set R10BIO_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(R10BIO_Uptodate, &r10_bio->state);
/* Maybe we can clear some bad blocks. */
if (rdev_has_badblock(rdev, r10_bio->devs[slot].addr,
r10_bio->sectors) &&
!discard_error) {
bio_put(bio);
if (repl)
r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
else
r10_bio->devs[slot].bio = IO_MADE_GOOD;
dec_rdev = 0;
set_bit(R10BIO_MadeGood, &r10_bio->state);
}
}
/*
*
* Let's see if all mirrored write operations have finished
* already.
*/
one_write_done(r10_bio);
if (dec_rdev)
rdev_dec_pending(rdev, conf->mddev);
if (to_put)
bio_put(to_put);
}
/*
* RAID10 layout manager
* As well as the chunksize and raid_disks count, there are two
* parameters: near_copies and far_copies.
* near_copies * far_copies must be <= raid_disks.
* Normally one of these will be 1.
* If both are 1, we get raid0.
* If near_copies == raid_disks, we get raid1.
*
* Chunks are laid out in raid0 style with near_copies copies of the
* first chunk, followed by near_copies copies of the next chunk and
* so on.
* If far_copies > 1, then after 1/far_copies of the array has been assigned
* as described above, we start again with a device offset of near_copies.
* So we effectively have another copy of the whole array further down all
* the drives, but with blocks on different drives.
* With this layout, and block is never stored twice on the one device.
*
* raid10_find_phys finds the sector offset of a given virtual sector
* on each device that it is on.
*
* raid10_find_virt does the reverse mapping, from a device and a
* sector offset to a virtual address
*/
static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
{
int n,f;
sector_t sector;
sector_t chunk;
sector_t stripe;
int dev;
int slot = 0;
int last_far_set_start, last_far_set_size;
last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
last_far_set_start *= geo->far_set_size;
last_far_set_size = geo->far_set_size;
last_far_set_size += (geo->raid_disks % geo->far_set_size);
/* now calculate first sector/dev */
chunk = r10bio->sector >> geo->chunk_shift;
sector = r10bio->sector & geo->chunk_mask;
chunk *= geo->near_copies;
stripe = chunk;
dev = sector_div(stripe, geo->raid_disks);
if (geo->far_offset)
stripe *= geo->far_copies;
sector += stripe << geo->chunk_shift;
/* and calculate all the others */
for (n = 0; n < geo->near_copies; n++) {
int d = dev;
int set;
sector_t s = sector;
r10bio->devs[slot].devnum = d;
r10bio->devs[slot].addr = s;
slot++;
for (f = 1; f < geo->far_copies; f++) {
set = d / geo->far_set_size;
d += geo->near_copies;
if ((geo->raid_disks % geo->far_set_size) &&
(d > last_far_set_start)) {
d -= last_far_set_start;
d %= last_far_set_size;
d += last_far_set_start;
} else {
d %= geo->far_set_size;
d += geo->far_set_size * set;
}
s += geo->stride;
r10bio->devs[slot].devnum = d;
r10bio->devs[slot].addr = s;
slot++;
}
dev++;
if (dev >= geo->raid_disks) {
dev = 0;
sector += (geo->chunk_mask + 1);
}
}
}
static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
{
struct geom *geo = &conf->geo;
if (conf->reshape_progress != MaxSector &&
((r10bio->sector >= conf->reshape_progress) !=
conf->mddev->reshape_backwards)) {
set_bit(R10BIO_Previous, &r10bio->state);
geo = &conf->prev;
} else
clear_bit(R10BIO_Previous, &r10bio->state);
__raid10_find_phys(geo, r10bio);
}
static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
{
sector_t offset, chunk, vchunk;
/* Never use conf->prev as this is only called during resync
* or recovery, so reshape isn't happening
*/
struct geom *geo = &conf->geo;
int far_set_start = (dev / geo->far_set_size) * geo->far_set_size;
int far_set_size = geo->far_set_size;
int last_far_set_start;
if (geo->raid_disks % geo->far_set_size) {
last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
last_far_set_start *= geo->far_set_size;
if (dev >= last_far_set_start) {
far_set_size = geo->far_set_size;
far_set_size += (geo->raid_disks % geo->far_set_size);
far_set_start = last_far_set_start;
}
}
offset = sector & geo->chunk_mask;
if (geo->far_offset) {
int fc;
chunk = sector >> geo->chunk_shift;
fc = sector_div(chunk, geo->far_copies);
dev -= fc * geo->near_copies;
if (dev < far_set_start)
dev += far_set_size;
} else {
while (sector >= geo->stride) {
sector -= geo->stride;
if (dev < (geo->near_copies + far_set_start))
dev += far_set_size - geo->near_copies;
else
dev -= geo->near_copies;
}
chunk = sector >> geo->chunk_shift;
}
vchunk = chunk * geo->raid_disks + dev;
sector_div(vchunk, geo->near_copies);
return (vchunk << geo->chunk_shift) + offset;
}
/*
* 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.
*/
/*
* FIXME: possibly should rethink readbalancing and do it differently
* depending on near_copies / far_copies geometry.
*/
static struct md_rdev *read_balance(struct r10conf *conf,
struct r10bio *r10_bio,
int *max_sectors)
{
const sector_t this_sector = r10_bio->sector;
int disk, slot;
int sectors = r10_bio->sectors;
int best_good_sectors;
sector_t new_distance, best_dist;
struct md_rdev *best_dist_rdev, *best_pending_rdev, *rdev = NULL;
int do_balance;
int best_dist_slot, best_pending_slot;
bool has_nonrot_disk = false;
unsigned int min_pending;
struct geom *geo = &conf->geo;
raid10_find_phys(conf, r10_bio);
best_dist_slot = -1;
min_pending = UINT_MAX;
best_dist_rdev = NULL;
best_pending_rdev = NULL;
best_dist = MaxSector;
best_good_sectors = 0;
do_balance = 1;
clear_bit(R10BIO_FailFast, &r10_bio->state);
if (raid1_should_read_first(conf->mddev, this_sector, sectors))
do_balance = 0;
for (slot = 0; slot < conf->copies ; slot++) {
sector_t first_bad;
int bad_sectors;
sector_t dev_sector;
unsigned int pending;
bool nonrot;
if (r10_bio->devs[slot].bio == IO_BLOCKED)
continue;
disk = r10_bio->devs[slot].devnum;
rdev = conf->mirrors[disk].replacement;
if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
r10_bio->devs[slot].addr + sectors >
rdev->recovery_offset)
rdev = conf->mirrors[disk].rdev;
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(In_sync, &rdev->flags) &&
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
continue;
dev_sector = r10_bio->devs[slot].addr;
if (is_badblock(rdev, dev_sector, sectors,
&first_bad, &bad_sectors)) {
if (best_dist < MaxSector)
/* Already have a better slot */
continue;
if (first_bad <= dev_sector) {
/* Cannot read here. If this is the
* 'primary' device, then we must not read
* beyond 'bad_sectors' from another device.
*/
bad_sectors -= (dev_sector - first_bad);
if (!do_balance && sectors > bad_sectors)
sectors = bad_sectors;
if (best_good_sectors > sectors)
best_good_sectors = sectors;
} else {
sector_t good_sectors =
first_bad - dev_sector;
if (good_sectors > best_good_sectors) {
best_good_sectors = good_sectors;
best_dist_slot = slot;
best_dist_rdev = rdev;
}
if (!do_balance)
/* Must read from here */
break;
}
continue;
} else
best_good_sectors = sectors;
if (!do_balance)
break;
nonrot = bdev_nonrot(rdev->bdev);
has_nonrot_disk |= nonrot;
pending = atomic_read(&rdev->nr_pending);
if (min_pending > pending && nonrot) {
min_pending = pending;
best_pending_slot = slot;
best_pending_rdev = rdev;
}
if (best_dist_slot >= 0)
/* At least 2 disks to choose from so failfast is OK */
set_bit(R10BIO_FailFast, &r10_bio->state);
/* This optimisation is debatable, and completely destroys
* sequential read speed for 'far copies' arrays. So only
* keep it for 'near' arrays, and review those later.
*/
if (geo->near_copies > 1 && !pending)
new_distance = 0;
/* for far > 1 always use the lowest address */
else if (geo->far_copies > 1)
new_distance = r10_bio->devs[slot].addr;
else
new_distance = abs(r10_bio->devs[slot].addr -
conf->mirrors[disk].head_position);
if (new_distance < best_dist) {
best_dist = new_distance;
best_dist_slot = slot;
best_dist_rdev = rdev;
}
}
if (slot >= conf->copies) {
if (has_nonrot_disk) {
slot = best_pending_slot;
rdev = best_pending_rdev;
} else {
slot = best_dist_slot;
rdev = best_dist_rdev;
}
}
if (slot >= 0) {
atomic_inc(&rdev->nr_pending);
r10_bio->read_slot = slot;
} else
rdev = NULL;
*max_sectors = best_good_sectors;
return rdev;
}
static void flush_pending_writes(struct r10conf *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);
raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
raid1_submit_write(bio);
bio = next;
cond_resched();
}
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.
*/
static void raise_barrier(struct r10conf *conf, int force)
{
write_seqlock_irq(&conf->resync_lock);
if (WARN_ON_ONCE(force && !conf->barrier))
force = false;
/* Wait until no block IO is waiting (unless 'force') */
wait_event_barrier(conf, force || !conf->nr_waiting);
/* block any new IO from starting */
WRITE_ONCE(conf->barrier, conf->barrier + 1);
/* Now wait for all pending IO to complete */
wait_event_barrier(conf, !atomic_read(&conf->nr_pending) &&
conf->barrier < RESYNC_DEPTH);
write_sequnlock_irq(&conf->resync_lock);
}
static void lower_barrier(struct r10conf *conf)
{
unsigned long flags;
write_seqlock_irqsave(&conf->resync_lock, flags);
WRITE_ONCE(conf->barrier, conf->barrier - 1);
write_sequnlock_irqrestore(&conf->resync_lock, flags);
wake_up(&conf->wait_barrier);
}
static bool stop_waiting_barrier(struct r10conf *conf)
{
struct bio_list *bio_list = current->bio_list;
struct md_thread *thread;
/* barrier is dropped */
if (!conf->barrier)
return true;
/*
* If there are already pending requests (preventing the barrier from
* rising completely), and the pre-process bio queue isn't empty, then
* don't wait, as we need to empty that queue to get the nr_pending
* count down.
*/
if (atomic_read(&conf->nr_pending) && bio_list &&
(!bio_list_empty(&bio_list[0]) || !bio_list_empty(&bio_list[1])))
return true;
/* daemon thread must exist while handling io */
thread = rcu_dereference_protected(conf->mddev->thread, true);
/*
* move on if io is issued from raid10d(), nr_pending is not released
* from original io(see handle_read_error()). All raise barrier is
* blocked until this io is done.
*/
if (thread->tsk == current) {
WARN_ON_ONCE(atomic_read(&conf->nr_pending) == 0);
return true;
}
return false;
}
static bool wait_barrier_nolock(struct r10conf *conf)
{
unsigned int seq = read_seqbegin(&conf->resync_lock);
if (READ_ONCE(conf->barrier))
return false;
atomic_inc(&conf->nr_pending);
if (!read_seqretry(&conf->resync_lock, seq))
return true;
if (atomic_dec_and_test(&conf->nr_pending))
wake_up_barrier(conf);
return false;
}
static bool wait_barrier(struct r10conf *conf, bool nowait)
{
bool ret = true;
if (wait_barrier_nolock(conf))
return true;
write_seqlock_irq(&conf->resync_lock);
if (conf->barrier) {
/* Return false when nowait flag is set */
if (nowait) {
ret = false;
} else {
conf->nr_waiting++;
mddev_add_trace_msg(conf->mddev, "raid10 wait barrier");
wait_event_barrier(conf, stop_waiting_barrier(conf));
conf->nr_waiting--;
}
if (!conf->nr_waiting)
wake_up(&conf->wait_barrier);
}
/* Only increment nr_pending when we wait */
if (ret)
atomic_inc(&conf->nr_pending);
write_sequnlock_irq(&conf->resync_lock);
return ret;
}
static void allow_barrier(struct r10conf *conf)
{
if ((atomic_dec_and_test(&conf->nr_pending)) ||
(conf->array_freeze_pending))
wake_up_barrier(conf);
}
static void freeze_array(struct r10conf *conf, int extra)
{
/* stop syncio and normal IO and wait for everything to
* go quiet.
* We increment barrier and nr_waiting, and then
* wait until nr_pending match nr_queued+extra
* This is called in the context of one normal IO request
* that has failed. Thus any sync request that might be pending
* will be blocked by nr_pending, and we need to wait for
* pending IO requests to complete or be queued for re-try.
* Thus the number queued (nr_queued) plus this request (extra)
* must match the number of pending IOs (nr_pending) before
* we continue.
*/
write_seqlock_irq(&conf->resync_lock);
conf->array_freeze_pending++;
WRITE_ONCE(conf->barrier, conf->barrier + 1);
conf->nr_waiting++;
wait_event_barrier_cmd(conf, atomic_read(&conf->nr_pending) ==
conf->nr_queued + extra, flush_pending_writes(conf));
conf->array_freeze_pending--;
write_sequnlock_irq(&conf->resync_lock);
}
static void unfreeze_array(struct r10conf *conf)
{
/* reverse the effect of the freeze */
write_seqlock_irq(&conf->resync_lock);
WRITE_ONCE(conf->barrier, conf->barrier - 1);
conf->nr_waiting--;
wake_up(&conf->wait_barrier);
write_sequnlock_irq(&conf->resync_lock);
}
static sector_t choose_data_offset(struct r10bio *r10_bio,
struct md_rdev *rdev)
{
if (!test_bit(MD_RECOVERY_RESHAPE, &rdev->mddev->recovery) ||
test_bit(R10BIO_Previous, &r10_bio->state))
return rdev->data_offset;
else
return rdev->new_data_offset;
}
static void raid10_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 r10conf *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);
raid1_prepare_flush_writes(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();
}
kfree(plug);
}
/*
* 1. 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.
* 2. If IO spans the reshape position. Need to wait for reshape to pass.
*/
static bool regular_request_wait(struct mddev *mddev, struct r10conf *conf,
struct bio *bio, sector_t sectors)
{
/* Bail out if REQ_NOWAIT is set for the bio */
if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return false;
}
while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
bio->bi_iter.bi_sector < conf->reshape_progress &&
bio->bi_iter.bi_sector + sectors > conf->reshape_progress) {
allow_barrier(conf);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return false;
}
mddev_add_trace_msg(conf->mddev, "raid10 wait reshape");
wait_event(conf->wait_barrier,
conf->reshape_progress <= bio->bi_iter.bi_sector ||
conf->reshape_progress >= bio->bi_iter.bi_sector +
sectors);
wait_barrier(conf, false);
}
return true;
}
static void raid10_read_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio, bool io_accounting)
{
struct r10conf *conf = mddev->private;
struct bio *read_bio;
const enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
struct md_rdev *rdev;
char b[BDEVNAME_SIZE];
int slot = r10_bio->read_slot;
struct md_rdev *err_rdev = NULL;
gfp_t gfp = GFP_NOIO;
if (slot >= 0 && r10_bio->devs[slot].rdev) {
/*
* This is an error retry, but we cannot
* safely dereference the rdev in the r10_bio,
* we must use the one in conf.
* If it has already been disconnected (unlikely)
* we lose the device name in error messages.
*/
int disk;
/*
* As we are blocking raid10, it is a little safer to
* use __GFP_HIGH.
*/
gfp = GFP_NOIO | __GFP_HIGH;
disk = r10_bio->devs[slot].devnum;
err_rdev = conf->mirrors[disk].rdev;
if (err_rdev)
snprintf(b, sizeof(b), "%pg", err_rdev->bdev);
else {
strcpy(b, "???");
/* This never gets dereferenced */
err_rdev = r10_bio->devs[slot].rdev;
}
}
if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors))
return;
rdev = read_balance(conf, r10_bio, &max_sectors);
if (!rdev) {
if (err_rdev) {
pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev), b,
(unsigned long long)r10_bio->sector);
}
raid_end_bio_io(r10_bio);
return;
}
if (err_rdev)
pr_err_ratelimited("md/raid10:%s: %pg: redirecting sector %llu to another mirror\n",
mdname(mddev),
rdev->bdev,
(unsigned long long)r10_bio->sector);
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
gfp, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
submit_bio_noacct(bio);
wait_barrier(conf, false);
bio = split;
r10_bio->master_bio = bio;
r10_bio->sectors = max_sectors;
}
slot = r10_bio->read_slot;
if (io_accounting) {
md_account_bio(mddev, &bio);
r10_bio->master_bio = bio;
}
read_bio = bio_alloc_clone(rdev->bdev, bio, gfp, &mddev->bio_set);
r10_bio->devs[slot].bio = read_bio;
r10_bio->devs[slot].rdev = rdev;
read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr +
choose_data_offset(r10_bio, rdev);
read_bio->bi_end_io = raid10_end_read_request;
read_bio->bi_opf = op | do_sync;
if (test_bit(FailFast, &rdev->flags) &&
test_bit(R10BIO_FailFast, &r10_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
read_bio->bi_private = r10_bio;
mddev_trace_remap(mddev, read_bio, r10_bio->sector);
submit_bio_noacct(read_bio);
return;
}
static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
struct bio *bio, bool replacement,
int n_copy)
{
const enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
const blk_opf_t do_fua = bio->bi_opf & REQ_FUA;
unsigned long flags;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
int devnum = r10_bio->devs[n_copy].devnum;
struct bio *mbio;
rdev = replacement ? conf->mirrors[devnum].replacement :
conf->mirrors[devnum].rdev;
mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, &mddev->bio_set);
if (replacement)
r10_bio->devs[n_copy].repl_bio = mbio;
else
r10_bio->devs[n_copy].bio = mbio;
mbio->bi_iter.bi_sector = (r10_bio->devs[n_copy].addr +
choose_data_offset(r10_bio, rdev));
mbio->bi_end_io = raid10_end_write_request;
mbio->bi_opf = op | do_sync | do_fua;
if (!replacement && test_bit(FailFast,
&conf->mirrors[devnum].rdev->flags)
&& enough(conf, devnum))
mbio->bi_opf |= MD_FAILFAST;
mbio->bi_private = r10_bio;
mddev_trace_remap(mddev, mbio, r10_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void *)rdev;
atomic_inc(&r10_bio->remaining);
if (!raid1_add_bio_to_plug(mddev, mbio, raid10_unplug, conf->copies)) {
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);
}
}
static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
{
int i;
struct r10conf *conf = mddev->private;
struct md_rdev *blocked_rdev;
retry_wait:
blocked_rdev = NULL;
for (i = 0; i < conf->copies; i++) {
struct md_rdev *rdev, *rrdev;
rdev = conf->mirrors[i].rdev;
rrdev = conf->mirrors[i].replacement;
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
atomic_inc(&rrdev->nr_pending);
blocked_rdev = rrdev;
break;
}
if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t dev_sector = r10_bio->devs[i].addr;
/*
* Discard request doesn't care the write result
* so it doesn't need to wait blocked disk here.
*/
if (!r10_bio->sectors)
continue;
if (rdev_has_badblock(rdev, dev_sector,
r10_bio->sectors) < 0) {
/*
* Mustn't write here until the bad block
* is acknowledged
*/
atomic_inc(&rdev->nr_pending);
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
}
}
if (unlikely(blocked_rdev)) {
/* Have to wait for this device to get unblocked, then retry */
allow_barrier(conf);
mddev_add_trace_msg(conf->mddev,
"raid10 %s wait rdev %d blocked",
__func__, blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf, false);
goto retry_wait;
}
}
static void raid10_write_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i;
sector_t sectors;
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);
/* Bail out if REQ_NOWAIT is set for the bio */
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);
}
sectors = r10_bio->sectors;
if (!regular_request_wait(mddev, conf, bio, sectors))
return;
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
(mddev->reshape_backwards
? (bio->bi_iter.bi_sector < conf->reshape_safe &&
bio->bi_iter.bi_sector + sectors > conf->reshape_progress)
: (bio->bi_iter.bi_sector + sectors > conf->reshape_safe &&
bio->bi_iter.bi_sector < conf->reshape_progress))) {
/* Need to update reshape_position in metadata */
mddev->reshape_position = conf->reshape_progress;
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
md_wakeup_thread(mddev->thread);
if (bio->bi_opf & REQ_NOWAIT) {
allow_barrier(conf);
bio_wouldblock_error(bio);
return;
}
mddev_add_trace_msg(conf->mddev,
"raid10 wait reshape metadata");
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
conf->reshape_safe = mddev->reshape_position;
}
/* 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 to those blocks. This potentially requires several
* writes to write around the bad blocks. Each set of writes
* gets its own r10_bio with a set of bios attached.
*/
r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
raid10_find_phys(conf, r10_bio);
wait_blocked_dev(mddev, r10_bio);
max_sectors = r10_bio->sectors;
for (i = 0; i < conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
struct md_rdev *rdev, *rrdev;
rdev = conf->mirrors[d].rdev;
rrdev = conf->mirrors[d].replacement;
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
rrdev = NULL;
r10_bio->devs[i].bio = NULL;
r10_bio->devs[i].repl_bio = NULL;
if (!rdev && !rrdev) {
set_bit(R10BIO_Degraded, &r10_bio->state);
continue;
}
if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
int is_bad;
is_bad = is_badblock(rdev, dev_sector, max_sectors,
&first_bad, &bad_sectors);
if (is_bad && first_bad <= dev_sector) {
/* Cannot write here at all */
bad_sectors -= (dev_sector - first_bad);
if (bad_sectors < max_sectors)
/* Mustn't write more than bad_sectors
* to other devices yet
*/
max_sectors = bad_sectors;
/* We don't set R10BIO_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 - dev_sector;
if (good_sectors < max_sectors)
max_sectors = good_sectors;
}
}
if (rdev) {
r10_bio->devs[i].bio = bio;
atomic_inc(&rdev->nr_pending);
}
if (rrdev) {
r10_bio->devs[i].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
}
}
if (max_sectors < r10_bio->sectors)
r10_bio->sectors = max_sectors;
if (r10_bio->sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, r10_bio->sectors,
GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
submit_bio_noacct(bio);
wait_barrier(conf, false);
bio = split;
r10_bio->master_bio = bio;
}
md_account_bio(mddev, &bio);
r10_bio->master_bio = bio;
atomic_set(&r10_bio->remaining, 1);
md_bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
for (i = 0; i < conf->copies; i++) {
if (r10_bio->devs[i].bio)
raid10_write_one_disk(mddev, r10_bio, bio, false, i);
if (r10_bio->devs[i].repl_bio)
raid10_write_one_disk(mddev, r10_bio, bio, true, i);
}
one_write_done(r10_bio);
}
static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
{
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
r10_bio->master_bio = bio;
r10_bio->sectors = sectors;
r10_bio->mddev = mddev;
r10_bio->sector = bio->bi_iter.bi_sector;
r10_bio->state = 0;
r10_bio->read_slot = -1;
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) *
conf->geo.raid_disks);
if (bio_data_dir(bio) == READ)
raid10_read_request(mddev, bio, r10_bio, true);
else
raid10_write_request(mddev, bio, r10_bio);
}
static void raid_end_discard_bio(struct r10bio *r10bio)
{
struct r10conf *conf = r10bio->mddev->private;
struct r10bio *first_r10bio;
while (atomic_dec_and_test(&r10bio->remaining)) {
allow_barrier(conf);
if (!test_bit(R10BIO_Discard, &r10bio->state)) {
first_r10bio = (struct r10bio *)r10bio->master_bio;
free_r10bio(r10bio);
r10bio = first_r10bio;
} else {
md_write_end(r10bio->mddev);
bio_endio(r10bio->master_bio);
free_r10bio(r10bio);
break;
}
}
}
static void raid10_end_discard_request(struct bio *bio)
{
struct r10bio *r10_bio = bio->bi_private;
struct r10conf *conf = r10_bio->mddev->private;
struct md_rdev *rdev = NULL;
int dev;
int slot, repl;
/*
* We don't care the return value of discard bio
*/
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
set_bit(R10BIO_Uptodate, &r10_bio->state);
dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
rdev = repl ? conf->mirrors[dev].replacement :
conf->mirrors[dev].rdev;
raid_end_discard_bio(r10_bio);
rdev_dec_pending(rdev, conf->mddev);
}
/*
* There are some limitations to handle discard bio
* 1st, the discard size is bigger than stripe_size*2.
* 2st, if the discard bio spans reshape progress, we use the old way to
* handle discard bio
*/
static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r10conf *conf = mddev->private;
struct geom *geo = &conf->geo;
int far_copies = geo->far_copies;
bool first_copy = true;
struct r10bio *r10_bio, *first_r10bio;
struct bio *split;
int disk;
sector_t chunk;
unsigned int stripe_size;
unsigned int stripe_data_disks;
sector_t split_size;
sector_t bio_start, bio_end;
sector_t first_stripe_index, last_stripe_index;
sector_t start_disk_offset;
unsigned int start_disk_index;
sector_t end_disk_offset;
unsigned int end_disk_index;
unsigned int remainder;
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
return -EAGAIN;
if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return 0;
}
wait_barrier(conf, false);
/*
* Check reshape again to avoid reshape happens after checking
* MD_RECOVERY_RESHAPE and before wait_barrier
*/
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
goto out;
if (geo->near_copies)
stripe_data_disks = geo->raid_disks / geo->near_copies +
geo->raid_disks % geo->near_copies;
else
stripe_data_disks = geo->raid_disks;
stripe_size = stripe_data_disks << geo->chunk_shift;
bio_start = bio->bi_iter.bi_sector;
bio_end = bio_end_sector(bio);
/*
* Maybe one discard bio is smaller than strip size or across one
* stripe and discard region is larger than one stripe size. For far
* offset layout, if the discard region is not aligned with stripe
* size, there is hole when we submit discard bio to member disk.
* For simplicity, we only handle discard bio which discard region
* is bigger than stripe_size * 2
*/
if (bio_sectors(bio) < stripe_size*2)
goto out;
/*
* Keep bio aligned with strip size.
*/
div_u64_rem(bio_start, stripe_size, &remainder);
if (remainder) {
split_size = stripe_size - remainder;
split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
/* Resend the fist split part */
submit_bio_noacct(split);
wait_barrier(conf, false);
}
div_u64_rem(bio_end, stripe_size, &remainder);
if (remainder) {
split_size = bio_sectors(bio) - remainder;
split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
/* Resend the second split part */
submit_bio_noacct(bio);
bio = split;
wait_barrier(conf, false);
}
bio_start = bio->bi_iter.bi_sector;
bio_end = bio_end_sector(bio);
/*
* Raid10 uses chunk as the unit to store data. It's similar like raid0.
* One stripe contains the chunks from all member disk (one chunk from
* one disk at the same HBA address). For layout detail, see 'man md 4'
*/
chunk = bio_start >> geo->chunk_shift;
chunk *= geo->near_copies;
first_stripe_index = chunk;
start_disk_index = sector_div(first_stripe_index, geo->raid_disks);
if (geo->far_offset)
first_stripe_index *= geo->far_copies;
start_disk_offset = (bio_start & geo->chunk_mask) +
(first_stripe_index << geo->chunk_shift);
chunk = bio_end >> geo->chunk_shift;
chunk *= geo->near_copies;
last_stripe_index = chunk;
end_disk_index = sector_div(last_stripe_index, geo->raid_disks);
if (geo->far_offset)
last_stripe_index *= geo->far_copies;
end_disk_offset = (bio_end & geo->chunk_mask) +
(last_stripe_index << geo->chunk_shift);
retry_discard:
r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
r10_bio->mddev = mddev;
r10_bio->state = 0;
r10_bio->sectors = 0;
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks);
wait_blocked_dev(mddev, r10_bio);
/*
* For far layout it needs more than one r10bio to cover all regions.
* Inspired by raid10_sync_request, we can use the first r10bio->master_bio
* to record the discard bio. Other r10bio->master_bio record the first
* r10bio. The first r10bio only release after all other r10bios finish.
* The discard bio returns only first r10bio finishes
*/
if (first_copy) {
r10_bio->master_bio = bio;
set_bit(R10BIO_Discard, &r10_bio->state);
first_copy = false;
first_r10bio = r10_bio;
} else
r10_bio->master_bio = (struct bio *)first_r10bio;
/*
* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
*/
for (disk = 0; disk < geo->raid_disks; disk++) {
struct md_rdev *rdev, *rrdev;
rdev = conf->mirrors[disk].rdev;
rrdev = conf->mirrors[disk].replacement;
r10_bio->devs[disk].bio = NULL;
r10_bio->devs[disk].repl_bio = NULL;
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
rrdev = NULL;
if (!rdev && !rrdev)
continue;
if (rdev) {
r10_bio->devs[disk].bio = bio;
atomic_inc(&rdev->nr_pending);
}
if (rrdev) {
r10_bio->devs[disk].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
}
}
atomic_set(&r10_bio->remaining, 1);
for (disk = 0; disk < geo->raid_disks; disk++) {
sector_t dev_start, dev_end;
struct bio *mbio, *rbio = NULL;
/*
* Now start to calculate the start and end address for each disk.
* The space between dev_start and dev_end is the discard region.
*
* For dev_start, it needs to consider three conditions:
* 1st, the disk is before start_disk, you can imagine the disk in
* the next stripe. So the dev_start is the start address of next
* stripe.
* 2st, the disk is after start_disk, it means the disk is at the
* same stripe of first disk
* 3st, the first disk itself, we can use start_disk_offset directly
*/
if (disk < start_disk_index)
dev_start = (first_stripe_index + 1) * mddev->chunk_sectors;
else if (disk > start_disk_index)
dev_start = first_stripe_index * mddev->chunk_sectors;
else
dev_start = start_disk_offset;
if (disk < end_disk_index)
dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
else if (disk > end_disk_index)
dev_end = last_stripe_index * mddev->chunk_sectors;
else
dev_end = end_disk_offset;
/*
* It only handles discard bio which size is >= stripe size, so
* dev_end > dev_start all the time.
* It doesn't need to use rcu lock to get rdev here. We already
* add rdev->nr_pending in the first loop.
*/
if (r10_bio->devs[disk].bio) {
struct md_rdev *rdev = conf->mirrors[disk].rdev;
mbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO,
&mddev->bio_set);
mbio->bi_end_io = raid10_end_discard_request;
mbio->bi_private = r10_bio;
r10_bio->devs[disk].bio = mbio;
r10_bio->devs[disk].devnum = disk;
atomic_inc(&r10_bio->remaining);
md_submit_discard_bio(mddev, rdev, mbio,
dev_start + choose_data_offset(r10_bio, rdev),
dev_end - dev_start);
bio_endio(mbio);
}
if (r10_bio->devs[disk].repl_bio) {
struct md_rdev *rrdev = conf->mirrors[disk].replacement;
rbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO,
&mddev->bio_set);
rbio->bi_end_io = raid10_end_discard_request;
rbio->bi_private = r10_bio;
r10_bio->devs[disk].repl_bio = rbio;
r10_bio->devs[disk].devnum = disk;
atomic_inc(&r10_bio->remaining);
md_submit_discard_bio(mddev, rrdev, rbio,
dev_start + choose_data_offset(r10_bio, rrdev),
dev_end - dev_start);
bio_endio(rbio);
}
}
if (!geo->far_offset && --far_copies) {
first_stripe_index += geo->stride >> geo->chunk_shift;
start_disk_offset += geo->stride;
last_stripe_index += geo->stride >> geo->chunk_shift;
end_disk_offset += geo->stride;
atomic_inc(&first_r10bio->remaining);
raid_end_discard_bio(r10_bio);
wait_barrier(conf, false);
goto retry_discard;
}
raid_end_discard_bio(r10_bio);
return 0;
out:
allow_barrier(conf);
return -EAGAIN;
}
static bool raid10_make_request(struct mddev *mddev, struct bio *bio)
{
struct r10conf *conf = mddev->private;
sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
int chunk_sects = chunk_mask + 1;
int sectors = bio_sectors(bio);
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
md_write_start(mddev, bio);
if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
if (!raid10_handle_discard(mddev, bio))
return true;
/*
* If this request crosses a chunk boundary, we need to split
* it.
*/
if (unlikely((bio->bi_iter.bi_sector & chunk_mask) +
sectors > chunk_sects
&& (conf->geo.near_copies < conf->geo.raid_disks
|| conf->prev.near_copies <
conf->prev.raid_disks)))
sectors = chunk_sects -
(bio->bi_iter.bi_sector &
(chunk_sects - 1));
__make_request(mddev, bio, sectors);
/* In case raid10d snuck in to freeze_array */
wake_up_barrier(conf);
return true;
}
static void raid10_status(struct seq_file *seq, struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
int i;
lockdep_assert_held(&mddev->lock);
if (conf->geo.near_copies < conf->geo.raid_disks)
seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
if (conf->geo.near_copies > 1)
seq_printf(seq, " %d near-copies", conf->geo.near_copies);
if (conf->geo.far_copies > 1) {
if (conf->geo.far_offset)
seq_printf(seq, " %d offset-copies", conf->geo.far_copies);
else
seq_printf(seq, " %d far-copies", conf->geo.far_copies);
if (conf->geo.far_set_size != conf->geo.raid_disks)
seq_printf(seq, " %d devices per set", conf->geo.far_set_size);
}
seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
conf->geo.raid_disks - mddev->degraded);
for (i = 0; i < conf->geo.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, "]");
}
/* check if there are enough drives for
* every block to appear on atleast one.
* Don't consider the device numbered 'ignore'
* as we might be about to remove it.
*/
static int _enough(struct r10conf *conf, int previous, int ignore)
{
int first = 0;
int has_enough = 0;
int disks, ncopies;
if (previous) {
disks = conf->prev.raid_disks;
ncopies = conf->prev.near_copies;
} else {
disks = conf->geo.raid_disks;
ncopies = conf->geo.near_copies;
}
do {
int n = conf->copies;
int cnt = 0;
int this = first;
while (n--) {
struct md_rdev *rdev;
if (this != ignore &&
(rdev = conf->mirrors[this].rdev) &&
test_bit(In_sync, &rdev->flags))
cnt++;
this = (this+1) % disks;
}
if (cnt == 0)
goto out;
first = (first + ncopies) % disks;
} while (first != 0);
has_enough = 1;
out:
return has_enough;
}
static int enough(struct r10conf *conf, int ignore)
{
/* when calling 'enough', both 'prev' and 'geo' must
* be stable.
* This is ensured if ->reconfig_mutex or ->device_lock
* is held.
*/
return _enough(conf, 0, ignore) &&
_enough(conf, 1, ignore);
}
/**
* raid10_error() - RAID10 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.
* 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 raid10_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) && !enough(conf, rdev->raid_disk)) {
set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
spin_unlock_irqrestore(&conf->device_lock, flags);
return;
}
}
if (test_and_clear_bit(In_sync, &rdev->flags))
mddev->degraded++;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_bit(Blocked, &rdev->flags);
set_bit(Faulty, &rdev->flags);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
spin_unlock_irqrestore(&conf->device_lock, flags);
pr_crit("md/raid10:%s: Disk failure on %pg, disabling device.\n"
"md/raid10:%s: Operation continuing on %d devices.\n",
mdname(mddev), rdev->bdev,
mdname(mddev), conf->geo.raid_disks - mddev->degraded);
}
static void print_conf(struct r10conf *conf)
{
int i;
struct md_rdev *rdev;
pr_debug("RAID10 conf printout:\n");
if (!conf) {
pr_debug("(!conf)\n");
return;
}
pr_debug(" --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
conf->geo.raid_disks);
lockdep_assert_held(&conf->mddev->reconfig_mutex);
for (i = 0; i < conf->geo.raid_disks; i++) {
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 r10conf *conf)
{
wait_barrier(conf, false);
allow_barrier(conf);
mempool_exit(&conf->r10buf_pool);
}
static int raid10_spare_active(struct mddev *mddev)
{
int i;
struct r10conf *conf = mddev->private;
struct raid10_info *tmp;
int count = 0;
unsigned long flags;
/*
* Find all non-in_sync disks within the RAID10 configuration
* and mark them in_sync
*/
for (i = 0; i < conf->geo.raid_disks; i++) {
tmp = conf->mirrors + i;
if (tmp->replacement
&& tmp->replacement->recovery_offset == MaxSector
&& !test_bit(Faulty, &tmp->replacement->flags)
&& !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
/* Replacement has just become active */
if (!tmp->rdev
|| !test_and_clear_bit(In_sync, &tmp->rdev->flags))
count++;
if (tmp->rdev) {
/* Replaced device not technically faulty,
* but we need to be sure it gets removed
* and never re-added.
*/
set_bit(Faulty, &tmp->rdev->flags);
sysfs_notify_dirent_safe(
tmp->rdev->sysfs_state);
}
sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
} else if (tmp->rdev
&& tmp->rdev->recovery_offset == MaxSector
&& !test_bit(Faulty, &tmp->rdev->flags)
&& !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
count++;
sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
}
}
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded -= count;
spin_unlock_irqrestore(&conf->device_lock, flags);
print_conf(conf);
return count;
}
static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
int err = -EEXIST;
int mirror, repl_slot = -1;
int first = 0;
int last = conf->geo.raid_disks - 1;
struct raid10_info *p;
if (mddev->recovery_cp < MaxSector)
/* only hot-add to in-sync arrays, as recovery is
* very different from resync
*/
return -EBUSY;
if (rdev->saved_raid_disk < 0 && !_enough(conf, 1, -1))
return -EINVAL;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
if (rdev->saved_raid_disk >= first &&
rdev->saved_raid_disk < conf->geo.raid_disks &&
conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
mirror = rdev->saved_raid_disk;
else
mirror = first;
for ( ; mirror <= last ; mirror++) {
p = &conf->mirrors[mirror];
if (p->recovery_disabled == mddev->recovery_disabled)
continue;
if (p->rdev) {
if (test_bit(WantReplacement, &p->rdev->flags) &&
p->replacement == NULL && repl_slot < 0)
repl_slot = mirror;
continue;
}
err = mddev_stack_new_rdev(mddev, rdev);
if (err)
return err;
p->head_position = 0;
p->recovery_disabled = mddev->recovery_disabled - 1;
rdev->raid_disk = mirror;
err = 0;
if (rdev->saved_raid_disk != mirror)
conf->fullsync = 1;
WRITE_ONCE(p->rdev, rdev);
break;
}
if (err && repl_slot >= 0) {
p = &conf->mirrors[repl_slot];
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = repl_slot;
err = mddev_stack_new_rdev(mddev, rdev);
if (err)
return err;
conf->fullsync = 1;
WRITE_ONCE(p->replacement, rdev);
}
print_conf(conf);
return err;
}
static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct md_rdev **rdevp;
struct raid10_info *p;
print_conf(conf);
if (unlikely(number >= mddev->raid_disks))
return 0;
p = conf->mirrors + number;
if (rdev == p->rdev)
rdevp = &p->rdev;
else if (rdev == p->replacement)
rdevp = &p->replacement;
else
return 0;
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 != p->recovery_disabled &&
(!p->replacement || p->replacement == rdev) &&
number < conf->geo.raid_disks &&
enough(conf, -1)) {
err = -EBUSY;
goto abort;
}
WRITE_ONCE(*rdevp, NULL);
if (p->replacement) {
/* We must have just cleared 'rdev' */
WRITE_ONCE(p->rdev, p->replacement);
clear_bit(Replacement, &p->replacement->flags);
WRITE_ONCE(p->replacement, NULL);
}
clear_bit(WantReplacement, &rdev->flags);
err = md_integrity_register(mddev);
abort:
print_conf(conf);
return err;
}
static void __end_sync_read(struct r10bio *r10_bio, struct bio *bio, int d)
{
struct r10conf *conf = r10_bio->mddev->private;
if (!bio->bi_status)
set_bit(R10BIO_Uptodate, &r10_bio->state);
else
/* The write handler will notice the lack of
* R10BIO_Uptodate and record any errors etc
*/
atomic_add(r10_bio->sectors,
&conf->mirrors[d].rdev->corrected_errors);
/* for reconstruct, we always reschedule after a read.
* for resync, only after all reads
*/
rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
atomic_dec_and_test(&r10_bio->remaining)) {
/* we have read all the blocks,
* do the comparison in process context in raid10d
*/
reschedule_retry(r10_bio);
}
}
static void end_sync_read(struct bio *bio)
{
struct r10bio *r10_bio = get_resync_r10bio(bio);
struct r10conf *conf = r10_bio->mddev->private;
int d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
__end_sync_read(r10_bio, bio, d);
}
static void end_reshape_read(struct bio *bio)
{
/* reshape read bio isn't allocated from r10buf_pool */
struct r10bio *r10_bio = bio->bi_private;
__end_sync_read(r10_bio, bio, r10_bio->read_slot);
}
static void end_sync_request(struct r10bio *r10_bio)
{
struct mddev *mddev = r10_bio->mddev;
while (atomic_dec_and_test(&r10_bio->remaining)) {
if (r10_bio->master_bio == NULL) {
/* the primary of several recovery bios */
sector_t s = r10_bio->sectors;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else
put_buf(r10_bio);
md_done_sync(mddev, s, 1);
break;
} else {
struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else
put_buf(r10_bio);
r10_bio = r10_bio2;
}
}
}
static void end_sync_write(struct bio *bio)
{
struct r10bio *r10_bio = get_resync_r10bio(bio);
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
int d;
int slot;
int repl;
struct md_rdev *rdev = NULL;
d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[d].replacement;
else
rdev = conf->mirrors[d].rdev;
if (bio->bi_status) {
if (repl)
md_error(mddev, rdev);
else {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
set_bit(R10BIO_WriteError, &r10_bio->state);
}
} else if (rdev_has_badblock(rdev, r10_bio->devs[slot].addr,
r10_bio->sectors)) {
set_bit(R10BIO_MadeGood, &r10_bio->state);
}
rdev_dec_pending(rdev, mddev);
end_sync_request(r10_bio);
}
/*
* Note: sync and recover and handled very differently for raid10
* This code is for resync.
* For resync, we read through virtual addresses and read all blocks.
* If there is any error, we schedule a write. The lowest numbered
* drive is authoritative.
* However requests come for physical address, so we need to map.
* For every physical address there are raid_disks/copies virtual addresses,
* which is always are least one, but is not necessarly an integer.
* This means that a physical address can span multiple chunks, so we may
* have to submit multiple io requests for a single sync request.
*/
/*
* We check if all blocks are in-sync and only write to blocks that
* aren't in sync
*/
static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i, first;
struct bio *tbio, *fbio;
int vcnt;
struct page **tpages, **fpages;
atomic_set(&r10_bio->remaining, 1);
/* find the first device with a block */
for (i=0; i<conf->copies; i++)
if (!r10_bio->devs[i].bio->bi_status)
break;
if (i == conf->copies)
goto done;
first = i;
fbio = r10_bio->devs[i].bio;
fbio->bi_iter.bi_size = r10_bio->sectors << 9;
fbio->bi_iter.bi_idx = 0;
fpages = get_resync_pages(fbio)->pages;
vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
/* now find blocks with errors */
for (i=0 ; i < conf->copies ; i++) {
int j, d;
struct md_rdev *rdev;
struct resync_pages *rp;
tbio = r10_bio->devs[i].bio;
if (tbio->bi_end_io != end_sync_read)
continue;
if (i == first)
continue;
tpages = get_resync_pages(tbio)->pages;
d = r10_bio->devs[i].devnum;
rdev = conf->mirrors[d].rdev;
if (!r10_bio->devs[i].bio->bi_status) {
/* We know that the bi_io_vec layout is the same for
* both 'first' and 'i', so we just compare them.
* All vec entries are PAGE_SIZE;
*/
int sectors = r10_bio->sectors;
for (j = 0; j < vcnt; j++) {
int len = PAGE_SIZE;
if (sectors < (len / 512))
len = sectors * 512;
if (memcmp(page_address(fpages[j]),
page_address(tpages[j]),
len))
break;
sectors -= len/512;
}
if (j == vcnt)
continue;
atomic64_add(r10_bio->sectors, &mddev->resync_mismatches);
if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
/* Don't fix anything. */
continue;
} else if (test_bit(FailFast, &rdev->flags)) {
/* Just give up on this device */
md_error(rdev->mddev, rdev);
continue;
}
/* Ok, we need to write this bio, either to correct an
* inconsistency or to correct an unreadable block.
* First we need to fixup bv_offset, bv_len and
* bi_vecs, as the read request might have corrupted these
*/
rp = get_resync_pages(tbio);
bio_reset(tbio, conf->mirrors[d].rdev->bdev, REQ_OP_WRITE);
md_bio_reset_resync_pages(tbio, rp, fbio->bi_iter.bi_size);
rp->raid_bio = r10_bio;
tbio->bi_private = rp;
tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
tbio->bi_end_io = end_sync_write;
bio_copy_data(tbio, fbio);
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
atomic_inc(&r10_bio->remaining);
md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio));
if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
tbio->bi_opf |= MD_FAILFAST;
tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset;
submit_bio_noacct(tbio);
}
/* Now write out to any replacement devices
* that are active
*/
for (i = 0; i < conf->copies; i++) {
int d;
tbio = r10_bio->devs[i].repl_bio;
if (!tbio || !tbio->bi_end_io)
continue;
if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
&& r10_bio->devs[i].bio != fbio)
bio_copy_data(tbio, fbio);
d = r10_bio->devs[i].devnum;
atomic_inc(&r10_bio->remaining);
md_sync_acct(conf->mirrors[d].replacement->bdev,
bio_sectors(tbio));
submit_bio_noacct(tbio);
}
done:
if (atomic_dec_and_test(&r10_bio->remaining)) {
md_done_sync(mddev, r10_bio->sectors, 1);
put_buf(r10_bio);
}
}
/*
* Now for the recovery code.
* Recovery happens across physical sectors.
* We recover all non-is_sync drives by finding the virtual address of
* each, and then choose a working drive that also has that virt address.
* There is a separate r10_bio for each non-in_sync drive.
* Only the first two slots are in use. The first for reading,
* The second for writing.
*
*/
static void fix_recovery_read_error(struct r10bio *r10_bio)
{
/* We got a read error during recovery.
* We repeat the read in smaller page-sized sections.
* If a read succeeds, write it to the new device or record
* a bad block if we cannot.
* If a read fails, record a bad block on both old and
* new devices.
*/
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
struct bio *bio = r10_bio->devs[0].bio;
sector_t sect = 0;
int sectors = r10_bio->sectors;
int idx = 0;
int dr = r10_bio->devs[0].devnum;
int dw = r10_bio->devs[1].devnum;
struct page **pages = get_resync_pages(bio)->pages;
while (sectors) {
int s = sectors;
struct md_rdev *rdev;
sector_t addr;
int ok;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
rdev = conf->mirrors[dr].rdev;
addr = r10_bio->devs[0].addr + sect,
ok = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_READ, false);
if (ok) {
rdev = conf->mirrors[dw].rdev;
addr = r10_bio->devs[1].addr + sect;
ok = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_WRITE, false);
if (!ok) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement,
&rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
}
}
if (!ok) {
/* We don't worry if we cannot set a bad block -
* it really is bad so there is no loss in not
* recording it yet
*/
rdev_set_badblocks(rdev, addr, s, 0);
if (rdev != conf->mirrors[dw].rdev) {
/* need bad block on destination too */
struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
addr = r10_bio->devs[1].addr + sect;
ok = rdev_set_badblocks(rdev2, addr, s, 0);
if (!ok) {
/* just abort the recovery */
pr_notice("md/raid10:%s: recovery aborted due to read error\n",
mdname(mddev));
conf->mirrors[dw].recovery_disabled
= mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR,
&mddev->recovery);
break;
}
}
}
sectors -= s;
sect += s;
idx++;
}
}
static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int d;
struct bio *wbio = r10_bio->devs[1].bio;
struct bio *wbio2 = r10_bio->devs[1].repl_bio;
/* Need to test wbio2->bi_end_io before we call
* submit_bio_noacct as if the former is NULL,
* the latter is free to free wbio2.
*/
if (wbio2 && !wbio2->bi_end_io)
wbio2 = NULL;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
fix_recovery_read_error(r10_bio);
if (wbio->bi_end_io)
end_sync_request(r10_bio);
if (wbio2)
end_sync_request(r10_bio);
return;
}
/*
* share the pages with the first bio
* and submit the write request
*/
d = r10_bio->devs[1].devnum;
if (wbio->bi_end_io) {
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio));
submit_bio_noacct(wbio);
}
if (wbio2) {
atomic_inc(&conf->mirrors[d].replacement->nr_pending);
md_sync_acct(conf->mirrors[d].replacement->bdev,
bio_sectors(wbio2));
submit_bio_noacct(wbio2);
}
}
static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
int sectors, struct page *page, enum req_op op)
{
if (rdev_has_badblock(rdev, sector, sectors) &&
(op == REQ_OP_READ || test_bit(WriteErrorSeen, &rdev->flags)))
return -1;
if (sync_page_io(rdev, sector, sectors << 9, page, op, false))
/* success */
return 1;
if (op == 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;
}
/*
* 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 r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
{
int sect = 0; /* Offset from r10_bio->sector */
int sectors = r10_bio->sectors, slot = r10_bio->read_slot;
struct md_rdev *rdev;
int d = r10_bio->devs[slot].devnum;
/* still own a reference to this rdev, so it cannot
* have been cleared recently.
*/
rdev = conf->mirrors[d].rdev;
if (test_bit(Faulty, &rdev->flags))
/* drive has already been failed, just ignore any
more fix_read_error() attempts */
return;
if (exceed_read_errors(mddev, rdev)) {
r10_bio->devs[slot].bio = IO_BLOCKED;
return;
}
while(sectors) {
int s = sectors;
int sl = slot;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
d = r10_bio->devs[sl].devnum;
rdev = conf->mirrors[d].rdev;
if (rdev &&
test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags) &&
rdev_has_badblock(rdev,
r10_bio->devs[sl].addr + sect,
s) == 0) {
atomic_inc(&rdev->nr_pending);
success = sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s<<9,
conf->tmppage,
REQ_OP_READ, false);
rdev_dec_pending(rdev, mddev);
if (success)
break;
}
sl++;
if (sl == conf->copies)
sl = 0;
} while (sl != slot);
if (!success) {
/* Cannot read from anywhere, just mark the block
* as bad on the first device to discourage future
* reads.
*/
int dn = r10_bio->devs[slot].devnum;
rdev = conf->mirrors[dn].rdev;
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[slot].addr
+ sect,
s, 0)) {
md_error(mddev, rdev);
r10_bio->devs[slot].bio
= IO_BLOCKED;
}
break;
}
start = sl;
/* write it back and re-read */
while (sl != slot) {
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = conf->mirrors[d].rdev;
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
if (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage, REQ_OP_WRITE)
== 0) {
/* Well, this device is dead */
pr_notice("md/raid10:%s: read correction write failed (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio,
rdev)),
rdev->bdev);
pr_notice("md/raid10:%s: %pg: failing drive\n",
mdname(mddev),
rdev->bdev);
}
rdev_dec_pending(rdev, mddev);
}
sl = start;
while (sl != slot) {
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = conf->mirrors[d].rdev;
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
switch (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage, REQ_OP_READ)) {
case 0:
/* Well, this device is dead */
pr_notice("md/raid10:%s: unable to read back corrected sectors (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
rdev->bdev);
pr_notice("md/raid10:%s: %pg: failing drive\n",
mdname(mddev),
rdev->bdev);
break;
case 1:
pr_info("md/raid10:%s: read error corrected (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
rdev->bdev);
atomic_add(s, &rdev->corrected_errors);
}
rdev_dec_pending(rdev, mddev);
}
sectors -= s;
sect += s;
}
}
static int narrow_write_error(struct r10bio *r10_bio, int i)
{
struct bio *bio = r10_bio->master_bio;
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
/* bio has the data to be written to slot '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.
*
* We currently own a reference to the rdev.
*/
int block_sectors;
sector_t sector;
int sectors;
int sect_to_write = r10_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 = r10_bio->sector;
sectors = ((r10_bio->sector + block_sectors)
& ~(sector_t)(block_sectors - 1))
- sector;
while (sect_to_write) {
struct bio *wbio;
sector_t wsector;
if (sectors > sect_to_write)
sectors = sect_to_write;
/* Write at 'sector' for 'sectors' */
wbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
&mddev->bio_set);
bio_trim(wbio, sector - bio->bi_iter.bi_sector, sectors);
wsector = r10_bio->devs[i].addr + (sector - r10_bio->sector);
wbio->bi_iter.bi_sector = wsector +
choose_data_offset(r10_bio, rdev);
wbio->bi_opf = REQ_OP_WRITE;
if (submit_bio_wait(wbio) < 0)
/* Failure! */
ok = rdev_set_badblocks(rdev, wsector,
sectors, 0)
&& ok;
bio_put(wbio);
sect_to_write -= sectors;
sector += sectors;
sectors = block_sectors;
}
return ok;
}
static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
{
int slot = r10_bio->read_slot;
struct bio *bio;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev = r10_bio->devs[slot].rdev;
/* 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 = r10_bio->devs[slot].bio;
bio_put(bio);
r10_bio->devs[slot].bio = NULL;
if (mddev->ro)
r10_bio->devs[slot].bio = IO_BLOCKED;
else if (!test_bit(FailFast, &rdev->flags)) {
freeze_array(conf, 1);
fix_read_error(conf, mddev, r10_bio);
unfreeze_array(conf);
} else
md_error(mddev, rdev);
rdev_dec_pending(rdev, mddev);
r10_bio->state = 0;
raid10_read_request(mddev, r10_bio->master_bio, r10_bio, false);
/*
* allow_barrier after re-submit to ensure no sync io
* can be issued while regular io pending.
*/
allow_barrier(conf);
}
static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
{
/* Some sort of write request has finished and it
* succeeded in writing where we thought there was a
* bad block. So forget the bad block.
* Or possibly if failed and we need to record
* a bad block.
*/
int m;
struct md_rdev *rdev;
if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
test_bit(R10BIO_IsRecover, &r10_bio->state)) {
for (m = 0; m < conf->copies; m++) {
int dev = r10_bio->devs[m].devnum;
rdev = conf->mirrors[dev].rdev;
if (r10_bio->devs[m].bio == NULL ||
r10_bio->devs[m].bio->bi_end_io == NULL)
continue;
if (!r10_bio->devs[m].bio->bi_status) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
} else {
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0))
md_error(conf->mddev, rdev);
}
rdev = conf->mirrors[dev].replacement;
if (r10_bio->devs[m].repl_bio == NULL ||
r10_bio->devs[m].repl_bio->bi_end_io == NULL)
continue;
if (!r10_bio->devs[m].repl_bio->bi_status) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
} else {
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0))
md_error(conf->mddev, rdev);
}
}
put_buf(r10_bio);
} else {
bool fail = false;
for (m = 0; m < conf->copies; m++) {
int dev = r10_bio->devs[m].devnum;
struct bio *bio = r10_bio->devs[m].bio;
rdev = conf->mirrors[dev].rdev;
if (bio == IO_MADE_GOOD) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
} else if (bio != NULL && bio->bi_status) {
fail = true;
if (!narrow_write_error(r10_bio, m)) {
md_error(conf->mddev, rdev);
set_bit(R10BIO_Degraded,
&r10_bio->state);
}
rdev_dec_pending(rdev, conf->mddev);
}
bio = r10_bio->devs[m].repl_bio;
rdev = conf->mirrors[dev].replacement;
if (rdev && bio == IO_MADE_GOOD) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
}
}
if (fail) {
spin_lock_irq(&conf->device_lock);
list_add(&r10_bio->retry_list, &conf->bio_end_io_list);
conf->nr_queued++;
spin_unlock_irq(&conf->device_lock);
/*
* In case freeze_array() is waiting for condition
* nr_pending == nr_queued + extra to be true.
*/
wake_up(&conf->wait_barrier);
md_wakeup_thread(conf->mddev->thread);
} else {
if (test_bit(R10BIO_WriteError,
&r10_bio->state))
close_write(r10_bio);
raid_end_bio_io(r10_bio);
}
}
}
static void raid10d(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r10bio *r10_bio;
unsigned long flags;
struct r10conf *conf = mddev->private;
struct list_head *head = &conf->retry_list;
struct blk_plug plug;
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)) {
while (!list_empty(&conf->bio_end_io_list)) {
list_move(conf->bio_end_io_list.prev, &tmp);
conf->nr_queued--;
}
}
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
r10_bio = list_first_entry(&tmp, struct r10bio,