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linux/drivers/md/raid10.c
Guoqing Jiang e9eeba28a1 md/raid10: read balance chooses idlest disk for SSD 
Andy reported that raid10 array with SSD disks has poor
read performance. Compared with raid1, RAID-1 can be 3x
faster than RAID-10 sometimes [1].

The thing is that raid10 chooses the low distance disk
for read request, however, the approach doesn't work
well for SSD device since it doesn't have spindle like
HDD, we should just read from the SSD which has less
pending IO like commit 9dedf60313 ("md/raid1: read
balance chooses idlest disk for SSD").

So this commit selects the idlest SSD disk for read if
array has none rotational disk, otherwise, read_balance
uses the previous distance priority algorithm. With the
change, the performance of raid10 gets increased largely
per Andy's test [2].

[1]. https://marc.info/?l=linux-raid&m=155915890004761&w=2
[2]. https://marc.info/?l=linux-raid&m=155990654223786&w=2

Tested-by: Andy Smith <andy@strugglers.net>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-15 01:37:35 -06:00

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// 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"
#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);
#define raid10_log(md, fmt, args...) \
do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0)
#include "raid1-10.c"
/*
* 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->copies]);
/* 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(gfp_flags, RESYNC_PAGES);
if (!bio)
goto out_free_bio;
r10_bio->devs[j].bio = bio;
if (!conf->have_replacement)
continue;
bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
if (!bio)
goto out_free_bio;
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 * 2]);
j = 0;
out_free_bio:
for ( ; j < nalloc; j++) {
if (r10_bio->devs[j].bio)
bio_put(r10_bio->devs[j].bio);
if (r10_bio->devs[j].repl_bio)
bio_put(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_put(bio);
}
bio = r10bio->devs[j].repl_bio;
if (bio)
bio_put(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->copies; 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 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->copies; slot++) {
if (r10_bio->devs[slot].bio == bio)
break;
if (r10_bio->devs[slot].repl_bio == bio) {
repl = 1;
break;
}
}
BUG_ON(slot == conf->copies);
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
*/
char b[BDEVNAME_SIZE];
pr_err_ratelimited("md/raid10:%s: %s: rescheduling sector %llu\n",
mdname(conf->mddev),
bdevname(rdev->bdev, b),
(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);
if (!test_bit(Faulty, &rdev->flags))
/* This is the only remaining device,
* We need to retry the write without
* FailFast
*/
set_bit(R10BIO_WriteError, &r10_bio->state);
else {
r10_bio->devs[slot].bio = NULL;
to_put = bio;
dec_rdev = 1;
}
} else
set_bit(R10BIO_WriteError, &r10_bio->state);
}
} 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.
*/
sector_t first_bad;
int bad_sectors;
/*
* 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 (is_badblock(rdev,
r10_bio->devs[slot].addr,
r10_bio->sectors,
&first_bad, &bad_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);
rcu_read_lock();
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);
/*
* Check if we can balance. We can balance on the whole
* device if no resync is going on (recovery is ok), or below
* the resync window. We take the first readable disk when
* above the resync window.
*/
if ((conf->mddev->recovery_cp < MaxSector
&& (this_sector + sectors >= conf->next_resync)) ||
(mddev_is_clustered(conf->mddev) &&
md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
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 = rcu_dereference(conf->mirrors[disk].replacement);
if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
rdev = rcu_dereference(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 = blk_queue_nonrot(bdev_get_queue(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;
rcu_read_unlock();
*max_sectors = best_good_sectors;
return rdev;
}
static int raid10_congested(struct mddev *mddev, int bits)
{
struct r10conf *conf = mddev->private;
int i, ret = 0;
if ((bits & (1 << WB_async_congested)) &&
conf->pending_count >= max_queued_requests)
return 1;
rcu_read_lock();
for (i = 0;
(i < conf->geo.raid_disks || i < conf->prev.raid_disks)
&& ret == 0;
i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev && !test_bit(Faulty, &rdev->flags)) {
struct request_queue *q = bdev_get_queue(rdev->bdev);
ret |= bdi_congested(q->backing_dev_info, bits);
}
}
rcu_read_unlock();
return ret;
}
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);
conf->pending_count = 0;
spin_unlock_irq(&conf->device_lock);
/*
* As this is called in a wait_event() loop (see freeze_array),
* current->state might be TASK_UNINTERRUPTIBLE which will
* cause a warning when we prepare to wait again. As it is
* rare that this path is taken, it is perfectly safe to force
* us to go around the wait_event() loop again, so the warning
* is a false-positive. Silence the warning by resetting
* thread state
*/
__set_current_state(TASK_RUNNING);
blk_start_plug(&plug);
/* flush any pending bitmap writes to disk
* before proceeding w/ I/O */
md_bitmap_unplug(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
struct md_rdev *rdev = (void*)bio->bi_disk;
bio->bi_next = NULL;
bio_set_dev(bio, rdev->bdev);
if (test_bit(Faulty, &rdev->flags)) {
bio_io_error(bio);
} else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
!blk_queue_discard(bio->bi_disk->queue)))
/* Just ignore it */
bio_endio(bio);
else
generic_make_request(bio);
bio = next;
}
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)
{
BUG_ON(force && !conf->barrier);
spin_lock_irq(&conf->resync_lock);
/* Wait until no block IO is waiting (unless 'force') */
wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
conf->resync_lock);
/* block any new IO from starting */
conf->barrier++;
/* Now wait for all pending IO to complete */
wait_event_lock_irq(conf->wait_barrier,
!atomic_read(&conf->nr_pending) && conf->barrier < RESYNC_DEPTH,
conf->resync_lock);
spin_unlock_irq(&conf->resync_lock);
}
static void lower_barrier(struct r10conf *conf)
{
unsigned long flags;
spin_lock_irqsave(&conf->resync_lock, flags);
conf->barrier--;
spin_unlock_irqrestore(&conf->resync_lock, flags);
wake_up(&conf->wait_barrier);
}
static void wait_barrier(struct r10conf *conf)
{
spin_lock_irq(&conf->resync_lock);
if (conf->barrier) {
conf->nr_waiting++;
/* Wait for the barrier to drop.
* However 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.
*/
raid10_log(conf->mddev, "wait barrier");
wait_event_lock_irq(conf->wait_barrier,
!conf->barrier ||
(atomic_read(&conf->nr_pending) &&
current->bio_list &&
(!bio_list_empty(&current->bio_list[0]) ||
!bio_list_empty(&current->bio_list[1]))),
conf->resync_lock);
conf->nr_waiting--;
if (!conf->nr_waiting)
wake_up(&conf->wait_barrier);
}
atomic_inc(&conf->nr_pending);
spin_unlock_irq(&conf->resync_lock);
}
static void allow_barrier(struct r10conf *conf)
{
if ((atomic_dec_and_test(&conf->nr_pending)) ||
(conf->array_freeze_pending))
wake_up(&conf->wait_barrier);
}
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.
*/
spin_lock_irq(&conf->resync_lock);
conf->array_freeze_pending++;
conf->barrier++;
conf->nr_waiting++;
wait_event_lock_irq_cmd(conf->wait_barrier,
atomic_read(&conf->nr_pending) == conf->nr_queued+extra,
conf->resync_lock,
flush_pending_writes(conf));
conf->array_freeze_pending--;
spin_unlock_irq(&conf->resync_lock);
}
static void unfreeze_array(struct r10conf *conf)
{
/* reverse the effect of the freeze */
spin_lock_irq(&conf->resync_lock);
conf->barrier--;
conf->nr_waiting--;
wake_up(&conf->wait_barrier);
spin_unlock_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;
}
struct raid10_plug_cb {
struct blk_plug_cb cb;
struct bio_list pending;
int pending_cnt;
};
static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
struct raid10_plug_cb *plug = container_of(cb, struct raid10_plug_cb,
cb);
struct mddev *mddev = plug->cb.data;
struct r10conf *conf = mddev->private;
struct bio *bio;
if (from_schedule || current->bio_list) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
conf->pending_count += plug->pending_cnt;
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_barrier);
md_wakeup_thread(mddev->thread);
kfree(plug);
return;
}
/* we aren't scheduling, so we can do the write-out directly. */
bio = bio_list_get(&plug->pending);
md_bitmap_unplug(mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
struct md_rdev *rdev = (void*)bio->bi_disk;
bio->bi_next = NULL;
bio_set_dev(bio, rdev->bdev);
if (test_bit(Faulty, &rdev->flags)) {
bio_io_error(bio);
} else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
!blk_queue_discard(bio->bi_disk->queue)))
/* Just ignore it */
bio_endio(bio);
else
generic_make_request(bio);
bio = next;
}
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 void regular_request_wait(struct mddev *mddev, struct r10conf *conf,
struct bio *bio, sector_t sectors)
{
wait_barrier(conf);
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) {
raid10_log(conf->mddev, "wait reshape");
allow_barrier(conf);
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);
}
}
static void raid10_read_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
struct bio *read_bio;
const int op = bio_op(bio);
const unsigned long 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 (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;
rcu_read_lock();
disk = r10_bio->devs[slot].devnum;
err_rdev = rcu_dereference(conf->mirrors[disk].rdev);
if (err_rdev)
bdevname(err_rdev->bdev, b);
else {
strcpy(b, "???");
/* This never gets dereferenced */
err_rdev = r10_bio->devs[slot].rdev;
}
rcu_read_unlock();
}
regular_request_wait(mddev, conf, bio, r10_bio->sectors);
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: %s: redirecting sector %llu to another mirror\n",
mdname(mddev),
bdevname(rdev->bdev, b),
(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);
generic_make_request(bio);
wait_barrier(conf);
bio = split;
r10_bio->master_bio = bio;
r10_bio->sectors = max_sectors;
}
slot = r10_bio->read_slot;
read_bio = bio_clone_fast(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);
bio_set_dev(read_bio, rdev->bdev);
read_bio->bi_end_io = raid10_end_read_request;
bio_set_op_attrs(read_bio, 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;
if (mddev->gendisk)
trace_block_bio_remap(read_bio->bi_disk->queue,
read_bio, disk_devt(mddev->gendisk),
r10_bio->sector);
generic_make_request(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 int op = bio_op(bio);
const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
const unsigned long do_fua = (bio->bi_opf & REQ_FUA);
unsigned long flags;
struct blk_plug_cb *cb;
struct raid10_plug_cb *plug = NULL;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
int devnum = r10_bio->devs[n_copy].devnum;
struct bio *mbio;
if (replacement) {
rdev = conf->mirrors[devnum].replacement;
if (rdev == NULL) {
/* Replacement just got moved to main 'rdev' */
smp_mb();
rdev = conf->mirrors[devnum].rdev;
}
} else
rdev = conf->mirrors[devnum].rdev;
mbio = bio_clone_fast(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));
bio_set_dev(mbio, rdev->bdev);
mbio->bi_end_io = raid10_end_write_request;
bio_set_op_attrs(mbio, 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;
if (conf->mddev->gendisk)
trace_block_bio_remap(mbio->bi_disk->queue,
mbio, disk_devt(conf->mddev->gendisk),
r10_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_disk = (void *)rdev;
atomic_inc(&r10_bio->remaining);
cb = blk_check_plugged(raid10_unplug, mddev, sizeof(*plug));
if (cb)
plug = container_of(cb, struct raid10_plug_cb, cb);
else
plug = NULL;
if (plug) {
bio_list_add(&plug->pending, mbio);
plug->pending_cnt++;
} else {
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
conf->pending_count++;
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(mddev->thread);
}
}
static void raid10_write_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i;
struct md_rdev *blocked_rdev;
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);
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;
regular_request_wait(mddev, conf, bio, sectors);
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);
raid10_log(conf->mddev, "wait reshape metadata");
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
conf->reshape_safe = mddev->reshape_position;
}
if (conf->pending_count >= max_queued_requests) {
md_wakeup_thread(mddev->thread);
raid10_log(mddev, "wait queued");
wait_event(conf->wait_barrier,
conf->pending_count < max_queued_requests);
}
/* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
* If there are known/acknowledged bad blocks on any device
* on which we have seen a write error, we want to avoid
* writing 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);
retry_write:
blocked_rdev = NULL;
rcu_read_lock();
max_sectors = r10_bio->sectors;
for (i = 0; i < conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
struct md_rdev *rrdev = rcu_dereference(
conf->mirrors[d].replacement);
if (rdev == rrdev)
rrdev = NULL;
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(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 < 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 (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);
}
}
rcu_read_unlock();
if (unlikely(blocked_rdev)) {
/* Have to wait for this device to get unblocked, then retry */
int j;
int d;
for (j = 0; j < i; j++) {
if (r10_bio->devs[j].bio) {
d = r10_bio->devs[j].devnum;
rdev_dec_pending(conf->mirrors[d].rdev, mddev);
}
if (r10_bio->devs[j].repl_bio) {
struct md_rdev *rdev;
d = r10_bio->devs[j].devnum;
rdev = conf->mirrors[d].replacement;
if (!rdev) {
/* Race with remove_disk */
smp_mb();
rdev = conf->mirrors[d].rdev;
}
rdev_dec_pending(rdev, mddev);
}
}
allow_barrier(conf);
raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf);
goto retry_write;
}
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);
generic_make_request(bio);
wait_barrier(conf);
bio = split;
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;
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * conf->copies);
if (bio_data_dir(bio) == READ)
raid10_read_request(mddev, bio, r10_bio);
else
raid10_write_request(mddev, bio, r10_bio);
}
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;
}
if (!md_write_start(mddev, bio))
return false;
/*
* 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(&conf->wait_barrier);
return true;
}
static void raid10_status(struct seq_file *seq, struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
int i;
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);
rcu_read_lock();
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_printf(seq, "]");
}
/* 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;
}
rcu_read_lock();
do {
int n = conf->copies;
int cnt = 0;
int this = first;
while (n--) {
struct md_rdev *rdev;
if (this != ignore &&
(rdev = rcu_dereference(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:
rcu_read_unlock();
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);
}
static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
{
char b[BDEVNAME_SIZE];
struct r10conf *conf = mddev->private;
unsigned long flags;
/*
* If it is not operational, then we have already marked it as dead
* else if it is the last working disks, ignore the error, let the
* next level up know.
* else mark the drive as failed
*/
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags)
&& !enough(conf, rdev->raid_disk)) {
/*
* Don't fail the drive, just return an IO error.
*/
spin_unlock_irqrestore(&conf->device_lock, flags);
return;
}
if (test_and_clear_bit(In_sync, &rdev->flags))
mddev->degraded++;
/*
* If recovery is running, make sure it aborts.
*/
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 %s, disabling device.\n"
"md/raid10:%s: Operation continuing on %d devices.\n",
mdname(mddev), bdevname(rdev->bdev, b),
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);
/* This is only called with ->reconfix_mutex held, so
* rcu protection of rdev is not needed */
for (i = 0; i < conf->geo.raid_disks; i++) {
char b[BDEVNAME_SIZE];
rdev = conf->mirrors[i].rdev;
if (rdev)
pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
i, !test_bit(In_sync, &rdev->flags),
!test_bit(Faulty, &rdev->flags),
bdevname(rdev->bdev,b));
}
}
static void close_sync(struct r10conf *conf)
{
wait_barrier(conf);
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;
int first = 0;
int last = conf->geo.raid_disks - 1;
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 (md_integrity_add_rdev(rdev, mddev))
return -ENXIO;
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++) {
struct raid10_info *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)
continue;
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = mirror;
err = 0;
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
conf->fullsync = 1;
rcu_assign_pointer(p->replacement, rdev);
break;
}
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
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;
rcu_assign_pointer(p->rdev, rdev);
break;
}
if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
print_conf(conf);
return err;
}
static int 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 = conf->mirrors + number;
print_conf(conf);
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;
}
*rdevp = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
*rdevp = rdev;
goto abort;
}
}
if (p->replacement) {
/* We must have just cleared 'rdev' */
p->rdev = p->replacement;
clear_bit(Replacement, &p->replacement->flags);
smp_mb(); /* Make sure other CPUs may see both as identical
* but will never see neither -- if they are careful.
*/
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;
sector_t first_bad;
int bad_sectors;
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 (is_badblock(rdev,
r10_bio->devs[slot].addr,
r10_bio->sectors,
&first_bad, &bad_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);
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_set_op_attrs(tbio, REQ_OP_WRITE, 0);
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;
bio_set_dev(tbio, conf->mirrors[d].rdev->bdev);
generic_make_request(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));
generic_make_request(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, 0, 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, 0, 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, *wbio2;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
fix_recovery_read_error(r10_bio);
end_sync_request(r10_bio);
return;
}
/*
* share the pages with the first bio
* and submit the write request
*/
d = r10_bio->devs[1].devnum;
wbio = r10_bio->devs[1].bio;
wbio2 = r10_bio->devs[1].repl_bio;
/* Need to test wbio2->bi_end_io before we call
* generic_make_request as if the former is NULL,
* the latter is free to free wbio2.
*/
if (wbio2 && !wbio2->bi_end_io)
wbio2 = NULL;
if (wbio->bi_end_io) {
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio));
generic_make_request(wbio);
}
if (wbio2) {
atomic_inc(&conf->mirrors[d].replacement->nr_pending);
md_sync_acct(conf->mirrors[d].replacement->bdev,
bio_sectors(wbio2));
generic_make_request(wbio2);
}
}
/*
* Used by fix_read_error() to decay the per rdev read_errors.
* We halve the read error count for every hour that has elapsed
* since the last recorded read error.
*
*/
static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
{
long cur_time_mon;
unsigned long hours_since_last;
unsigned int read_errors = atomic_read(&rdev->read_errors);
cur_time_mon = ktime_get_seconds();
if (rdev->last_read_error == 0) {
/* first time we've seen a read error */
rdev->last_read_error = cur_time_mon;
return;
}
hours_since_last = (long)(cur_time_mon -
rdev->last_read_error) / 3600;
rdev->last_read_error = cur_time_mon;
/*
* if hours_since_last is > the number of bits in read_errors
* just set read errors to 0. We do this to avoid
* overflowing the shift of read_errors by hours_since_last.
*/
if (hours_since_last >= 8 * sizeof(read_errors))
atomic_set(&rdev->read_errors, 0);
else
atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
}
static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
int sectors, struct page *page, int rw)
{
sector_t first_bad;
int bad_sectors;
if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
&& (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
return -1;
if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
/* success */
return 1;
if (rw == WRITE) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
}
/* need to record an error - either for the block or the device */
if (!rdev_set_badblocks(rdev, sector, sectors, 0))
md_error(rdev->mddev, rdev);
return 0;
}
/*
* 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;
struct md_rdev *rdev;
int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
int d = r10_bio->devs[r10_bio->read_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;
check_decay_read_errors(mddev, rdev);
atomic_inc(&rdev->read_errors);
if (atomic_read(&rdev->read_errors) > max_read_errors) {
char b[BDEVNAME_SIZE];
bdevname(rdev->bdev, b);
pr_notice("md/raid10:%s: %s: Raid device exceeded read_error threshold [cur %d:max %d]\n",
mdname(mddev), b,
atomic_read(&rdev->read_errors), max_read_errors);
pr_notice("md/raid10:%s: %s: Failing raid device\n",
mdname(mddev), b);
md_error(mddev, rdev);
r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
return;
}
while(sectors) {
int s = sectors;
int sl = r10_bio->read_slot;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
rcu_read_lock();
do {
sector_t first_bad;
int bad_sectors;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags) &&
is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
&first_bad, &bad_sectors) == 0) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
success = sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s<<9,
conf->tmppage,
REQ_OP_READ, 0, false);
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
if (success)
break;
}
sl++;
if (sl == conf->copies)
sl = 0;
} while (!success && sl != r10_bio->read_slot);
rcu_read_unlock();
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[r10_bio->read_slot].devnum;
rdev = conf->mirrors[dn].rdev;
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[r10_bio->read_slot].addr
+ sect,
s, 0)) {
md_error(mddev, rdev);
r10_bio->devs[r10_bio->read_slot].bio
= IO_BLOCKED;
}
break;
}
start = sl;
/* write it back and re-read */
rcu_read_lock();
while (sl != r10_bio->read_slot) {
char b[BDEVNAME_SIZE];
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage, WRITE)
== 0) {
/* Well, this device is dead */
pr_notice("md/raid10:%s: read correction write failed (%d sectors at %llu on %s)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio,
rdev)),
bdevname(rdev->bdev, b));
pr_notice("md/raid10:%s: %s: failing drive\n",
mdname(mddev),
bdevname(rdev->bdev, b));
}
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
}
sl = start;
while (sl != r10_bio->read_slot) {
char b[BDEVNAME_SIZE];
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
switch (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage,
READ)) {
case 0:
/* Well, this device is dead */
pr_notice("md/raid10:%s: unable to read back corrected sectors (%d sectors at %llu on %s)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
bdevname(rdev->bdev, b));
pr_notice("md/raid10:%s: %s: failing drive\n",
mdname(mddev),
bdevname(rdev->bdev, b));
break;
case 1:
pr_info("md/raid10:%s: read error corrected (%d sectors at %llu on %s)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
bdevname(rdev->bdev, b));
atomic_add(s, &rdev->corrected_errors);
}
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
}
rcu_read_unlock();
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_clone_fast(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);
bio_set_dev(wbio, rdev->bdev);
bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
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);
allow_barrier(conf);
r10_bio->state = 0;
raid10_read_request(mddev, r10_bio->master_bio, r10_bio);
}
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,
retry_list);
list_del(&r10_bio->retry_list);
if (mddev->degraded)
set_bit(R10BIO_Degraded, &r10_bio->state);
if (test_bit(R10BIO_WriteError,
&r10_bio->state))
close_write(r10_bio);
raid_end_bio_io(r10_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;
}
r10_bio = list_entry(head->prev, struct r10bio, retry_list);
list_del(head->prev);
conf->nr_queued--;
spin_unlock_irqrestore(&conf->device_lock, flags);
mddev = r10_bio->mddev;
conf = mddev->private;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
handle_write_completed(conf, r10_bio);
else if (test_bit(R10BIO_IsReshape, &r10_bio->state))
reshape_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsSync, &r10_bio->state))
sync_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
recovery_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_ReadError, &r10_bio->state))
handle_read_error(mddev, r10_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 r10conf *conf)
{
int ret, buffs, i;
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
BUG_ON(mempool_initialized(&conf->r10buf_pool));
conf->have_replacement = 0;
for (i = 0; i < conf->geo.raid_disks; i++)
if (conf->mirrors[i].replacement)
conf->have_replacement = 1;
ret = mempool_init(&conf->r10buf_pool, buffs,
r10buf_pool_alloc, r10buf_pool_free, conf);
if (ret)
return ret;
conf->next_resync = 0;
return 0;
}
static struct r10bio *raid10_alloc_init_r10buf(struct r10conf *conf)
{
struct r10bio *r10bio = mempool_alloc(&conf->r10buf_pool, GFP_NOIO);
struct rsync_pages *rp;
struct bio *bio;
int nalloc;
int i;
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 */
for (i = 0; i < nalloc; i++) {
bio = r10bio->devs[i].bio;
rp = bio->bi_private;
bio_reset(bio);
bio->bi_private = rp;
bio = r10bio->devs[i].repl_bio;
if (bio) {
rp = bio->bi_private;
bio_reset(bio);
bio->bi_private = rp;
}
}
return r10bio;
}
/*
* Set cluster_sync_high since we need other nodes to add the
* range [cluster_sync_low, cluster_sync_high] to suspend list.
*/
static void raid10_set_cluster_sync_high(struct r10conf *conf)
{
sector_t window_size;
int extra_chunk, chunks;
/*
* First, here we define "stripe" as a unit which across
* all member devices one time, so we get chunks by use
* raid_disks / near_copies. Otherwise, if near_copies is
* close to raid_disks, then resync window could increases
* linearly with the increase of raid_disks, which means
* we will suspend a really large IO window while it is not
* necessary. If raid_disks is not divisible by near_copies,
* an extra chunk is needed to ensure the whole "stripe" is
* covered.
*/
chunks = conf->geo.raid_disks / conf->geo.near_copies;
if (conf->geo.raid_disks % conf->geo.near_copies == 0)
extra_chunk = 0;
else
extra_chunk = 1;
window_size = (chunks + extra_chunk) * conf->mddev->chunk_sectors;
/*
* At least use a 32M window to align with raid1's resync window
*/
window_size = (CLUSTER_RESYNC_WINDOW_SECTORS > window_size) ?
CLUSTER_RESYNC_WINDOW_SECTORS : window_size;
conf->cluster_sync_high = conf->cluster_sync_low + window_size;
}
/*
* 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.
*
* Resync and recovery are handled very differently.
* We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
*
* For resync, we iterate over virtual addresses, read all copies,
* and update if there are differences. If only one copy is live,
* skip it.
* For recovery, we iterate over physical addresses, read a good
* value for each non-in_sync drive, and over-write.
*
* So, for recovery we may have several outstanding complex requests for a
* given address, one for each out-of-sync device. We model this by allocating
* a number of r10_bio structures, one for each out-of-sync device.
* As we setup these structures, we collect all bio's together into a list
* which we then process collectively to add pages, and then process again
* to pass to generic_make_request.
*
* The r10_bio structures are linked using a borrowed master_bio pointer.
* This link is counted in ->remaining. When the r10_bio that points to NULL
* has its remaining count decremented to 0, the whole complex operation
* is complete.
*
*/
static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
struct bio *biolist = NULL, *bio;
sector_t max_sector, nr_sectors;
int i;
int max_sync;
sector_t sync_blocks;
sector_t sectors_skipped = 0;
int chunks_skipped = 0;
sector_t chunk_mask = conf->geo.chunk_mask;
int page_idx = 0;
if (!mempool_initialized(&conf->r10buf_pool))
if (init_resync(conf))
return 0;
/*
* Allow skipping a full rebuild for incremental assembly
* of a clean array, like RAID1 does.
*/
if (mddev->bitmap == NULL &&
mddev->recovery_cp == MaxSector &&
mddev->reshape_position == MaxSector &&
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
conf->fullsync == 0) {
*skipped = 1;
return mddev->dev_sectors - sector_nr;
}
skipped:
max_sector = mddev->dev_sectors;
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
max_sector = mddev->resync_max_sectors;
if (sector_nr >= max_sector) {
conf->cluster_sync_low = 0;
conf->cluster_sync_high = 0;
/* If we aborted, we need to abort the
* sync on the 'current' bitmap chucks (there can
* be several when recovering multiple devices).
* as we may have started syncing it but not finished.
* We can find the current address in
* mddev->curr_resync, but for recovery,
* we need to convert that to several
* virtual addresses.
*/
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
end_reshape(conf);
close_sync(conf);
return 0;
}
if (mddev->curr_resync < max_sector) { /* aborted */
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
else for (i = 0; i < conf->geo.raid_disks; i++) {
sector_t sect =
raid10_find_virt(conf, mddev->curr_resync, i);
md_bitmap_end_sync(mddev->bitmap, sect,
&sync_blocks, 1);
}
} else {
/* completed sync */
if ((!mddev->bitmap || conf->fullsync)
&& conf->have_replacement
&& test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* Completed a full sync so the replacements
* are now fully recovered.
*/
rcu_read_lock();
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev =
rcu_dereference(conf->mirrors[i].replacement);
if (rdev)
rdev->recovery_offset = MaxSector;
}
rcu_read_unlock();
}
conf->fullsync = 0;
}
md_bitmap_close_sync(mddev->bitmap);
close_sync(conf);
*skipped = 1;
return sectors_skipped;
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
return reshape_request(mddev, sector_nr, skipped);
if (chunks_skipped >= conf->geo.raid_disks) {
/* if there has been nothing to do on any drive,
* then there is nothing to do at all..
*/
*skipped = 1;
return (max_sector - sector_nr) + sectors_skipped;
}
if (max_sector > mddev->resync_max)
max_sector = mddev->resync_max; /* Don't do IO beyond here */
/* make sure whole request will fit in a chunk - if chunks
* are meaningful
*/
if (conf->geo.near_copies < conf->geo.raid_disks &&
max_sector > (sector_nr | chunk_mask))
max_sector = (sector_nr | chunk_mask) + 1;
/*
* If there is non-resync activity waiting for a turn, then let it
* though before starting on this new sync request.
*/
if (conf->nr_waiting)
schedule_timeout_uninterruptible(1);
/* Again, very different code for resync and recovery.
* Both must result in an r10bio with a list of bios that
* have bi_end_io, bi_sector, bi_disk set,
* and bi_private set to the r10bio.
* For recovery, we may actually create several r10bios
* with 2 bios in each, that correspond to the bios in the main one.
* In this case, the subordinate r10bios link back through a
* borrowed master_bio pointer, and the counter in the master
* includes a ref from each subordinate.
*/
/* First, we decide what to do and set ->bi_end_io
* To end_sync_read if we want to read, and
* end_sync_write if we will want to write.
*/
max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* recovery... the complicated one */
int j;
r10_bio = NULL;
for (i = 0 ; i < conf->geo.raid_disks; i++) {
int still_degraded;
struct r10bio *rb2;
sector_t sect;
int must_sync;
int any_working;
int need_recover = 0;
int need_replace = 0;
struct raid10_info *mirror = &conf->mirrors[i];
struct md_rdev *mrdev, *mreplace;
rcu_read_lock();
mrdev = rcu_dereference(mirror->rdev);
mreplace = rcu_dereference(mirror->replacement);
if (mrdev != NULL &&
!test_bit(Faulty, &mrdev->flags) &&
!test_bit(In_sync, &mrdev->flags))
need_recover = 1;
if (mreplace != NULL &&
!test_bit(Faulty, &mreplace->flags))
need_replace = 1;
if (!need_recover && !need_replace) {
rcu_read_unlock();
continue;
}
still_degraded = 0;
/* want to reconstruct this device */
rb2 = r10_bio;
sect = raid10_find_virt(conf, sector_nr, i);
if (sect >= mddev->resync_max_sectors) {
/* last stripe is not complete - don't
* try to recover this sector.
*/
rcu_read_unlock();
continue;
}
if (mreplace && test_bit(Faulty, &mreplace->flags))
mreplace = NULL;
/* Unless we are doing a full sync, or a replacement
* we only need to recover the block if it is set in
* the bitmap
*/
must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
&sync_blocks, 1);
if (sync_blocks < max_sync)
max_sync = sync_blocks;
if (!must_sync &&
mreplace == NULL &&
!conf->fullsync) {
/* yep, skip the sync_blocks here, but don't assume
* that there will never be anything to do here
*/
chunks_skipped = -1;
rcu_read_unlock();
continue;
}
atomic_inc(&mrdev->nr_pending);
if (mreplace)
atomic_inc(&mreplace->nr_pending);
rcu_read_unlock();
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
raise_barrier(conf, rb2 != NULL);
atomic_set(&r10_bio->remaining, 0);
r10_bio->master_bio = (struct bio*)rb2;
if (rb2)
atomic_inc(&rb2->remaining);
r10_bio->mddev = mddev;
set_bit(R10BIO_IsRecover, &r10_bio->state);
r10_bio->sector = sect;
raid10_find_phys(conf, r10_bio);
/* Need to check if the array will still be
* degraded
*/
rcu_read_lock();
for (j = 0; j < conf->geo.raid_disks; j++) {
struct md_rdev *rdev = rcu_dereference(
conf->mirrors[j].rdev);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
still_degraded = 1;
break;
}
}
must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
&sync_blocks, still_degraded);
any_working = 0;
for (j=0; j<conf->copies;j++) {
int k;
int d = r10_bio->devs[j].devnum;
sector_t from_addr, to_addr;
struct md_rdev *rdev =
rcu_dereference(conf->mirrors[d].rdev);
sector_t sector, first_bad;
int bad_sectors;
if (!rdev ||
!test_bit(In_sync, &rdev->flags))
continue;
/* This is where we read from */
any_working = 1;
sector = r10_bio->devs[j].addr;
if (is_badblock(rdev, sector, max_sync,
&first_bad, &bad_sectors)) {
if (first_bad > sector)
max_sync = first_bad - sector;
else {
bad_sectors -= (sector
- first_bad);
if (max_sync > bad_sectors)
max_sync = bad_sectors;
continue;
}
}
bio = r10_bio->devs[0].bio;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_read;
bio_set_op_attrs(bio, REQ_OP_READ, 0);
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
from_addr = r10_bio->devs[j].addr;
bio->bi_iter.bi_sector = from_addr +
rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
atomic_inc(&rdev->nr_pending);
/* and we write to 'i' (if not in_sync) */
for (k=0; k<conf->copies; k++)
if (r10_bio->devs[k].devnum == i)
break;
BUG_ON(k == conf->copies);
to_addr = r10_bio->devs[k].addr;
r10_bio->devs[0].devnum = d;
r10_bio->devs[0].addr = from_addr;
r10_bio->devs[1].devnum = i;
r10_bio->devs[1].addr = to_addr;
if (need_recover) {
bio = r10_bio->devs[1].bio;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
bio->bi_iter.bi_sector = to_addr
+ mrdev->data_offset;
bio_set_dev(bio, mrdev->bdev);
atomic_inc(&r10_bio->remaining);
} else
r10_bio->devs[1].bio->bi_end_io = NULL;
/* and maybe write to replacement */
bio = r10_bio->devs[1].repl_bio;
if (bio)
bio->bi_end_io = NULL;
/* Note: if need_replace, then bio
* cannot be NULL as r10buf_pool_alloc will
* have allocated it.
*/
if (!need_replace)
break;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
bio->bi_iter.bi_sector = to_addr +
mreplace->data_offset;
bio_set_dev(bio, mreplace->bdev);
atomic_inc(&r10_bio->remaining);
break;
}
rcu_read_unlock();
if (j == conf->copies) {
/* Cannot recover, so abort the recovery or
* record a bad block */
if (any_working) {
/* problem is that there are bad blocks
* on other device(s)
*/
int k;
for (k = 0; k < conf->copies; k++)
if (r10_bio->devs[k].devnum == i)
break;
if (!test_bit(In_sync,
&mrdev->flags)
&& !rdev_set_badblocks(
mrdev,
r10_bio->devs[k].addr,
max_sync, 0))
any_working = 0;
if (mreplace &&
!rdev_set_badblocks(
mreplace,
r10_bio->devs[k].addr,
max_sync, 0))
any_working = 0;
}
if (!any_working) {
if (!test_and_set_bit(MD_RECOVERY_INTR,
&mddev->recovery))
pr_warn("md/raid10:%s: insufficient working devices for recovery.\n",
mdname(mddev));
mirror->recovery_disabled
= mddev->recovery_disabled;
}
put_buf(r10_bio);
if (rb2)
atomic_dec(&rb2->remaining);
r10_bio = rb2;
rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
break;
}
rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) {
/* Only want this if there is elsewhere to
* read from. 'j' is currently the first
* readable copy.
*/
int targets = 1;
for (; j < conf->copies; j++) {
int d = r10_bio->devs[j].devnum;
if (conf->mirrors[d].rdev &&
test_bit(In_sync,
&conf->mirrors[d].rdev->flags))
targets++;
}
if (targets == 1)
r10_bio->devs[0].bio->bi_opf
&= ~MD_FAILFAST;
}
}
if (biolist == NULL) {
while (r10_bio) {
struct r10bio *rb2 = r10_bio;
r10_bio = (struct r10bio*) rb2->master_bio;
rb2->master_bio = NULL;
put_buf(rb2);
}
goto giveup;
}
} else {
/* resync. Schedule a read for every block at this virt offset */
int count = 0;
/*
* Since curr_resync_completed could probably not update in
* time, and we will set cluster_sync_low based on it.
* Let's check against "sector_nr + 2 * RESYNC_SECTORS" for
* safety reason, which ensures curr_resync_completed is
* updated in bitmap_cond_end_sync.
*/
md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
mddev_is_clustered(mddev) &&
(sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
&sync_blocks, mddev->degraded) &&
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
&mddev->recovery)) {
/* We can skip this block */
*skipped = 1;
return sync_blocks + sectors_skipped;
}
if (sync_blocks < max_sync)
max_sync = sync_blocks;
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
r10_bio->mddev = mddev;
atomic_set(&r10_bio->remaining, 0);
raise_barrier(conf, 0);
conf->next_resync = sector_nr;
r10_bio->master_bio = NULL;
r10_bio->sector = sector_nr;
set_bit(R10BIO_IsSync, &r10_bio->state);
raid10_find_phys(conf, r10_bio);
r10_bio->sectors = (sector_nr | chunk_mask) - sector_nr + 1;
for (i = 0; i < conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
sector_t first_bad, sector;
int bad_sectors;
struct md_rdev *rdev;
if (r10_bio->devs[i].repl_bio)
r10_bio->devs[i].repl_bio->bi_end_io = NULL;
bio = r10_bio->devs[i].bio;
bio->bi_status = BLK_STS_IOERR;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
sector = r10_bio->devs[i].addr;
if (is_badblock(rdev, sector, max_sync,
&first_bad, &bad_sectors)) {
if (first_bad > sector)
max_sync = first_bad - sector;
else {
bad_sectors -= (sector - first_bad);
if (max_sync > bad_sectors)
max_sync = bad_sectors;
rcu_read_unlock();
continue;
}
}
atomic_inc(&rdev->nr_pending);
atomic_inc(&r10_bio->remaining);
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_read;
bio_set_op_attrs(bio, REQ_OP_READ, 0);
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
bio->bi_iter.bi_sector = sector + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
count++;
rdev = rcu_dereference(conf->mirrors[d].replacement);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
atomic_inc(&rdev->nr_pending);
/* Need to set up for writing to the replacement */
bio = r10_bio->devs[i].repl_bio;
bio->bi_status = BLK_STS_IOERR;
sector = r10_bio->devs[i].addr;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
bio->bi_iter.bi_sector = sector + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
count++;
rcu_read_unlock();
}
if (count < 2) {
for (i=0; i<conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
if (r10_bio->devs[i].bio->bi_end_io)
rdev_dec_pending(conf->mirrors[d].rdev,
mddev);
if (r10_bio->devs[i].repl_bio &&
r10_bio->devs[i].repl_bio->bi_end_io)
rdev_dec_pending(
conf->mirrors[d].replacement,
mddev);
}
put_buf(r10_bio);
biolist = NULL;
goto giveup;
}
}
nr_sectors = 0;
if (sector_nr + max_sync < max_sector)
max_sector = sector_nr + max_sync;
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;
for (bio= biolist ; bio ; bio=bio->bi_next) {
struct resync_pages *rp = get_resync_pages(bio);
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;
} while (++page_idx < RESYNC_PAGES);
r10_bio->sectors = nr_sectors;
if (mddev_is_clustered(mddev) &&
test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* It is resync not recovery */
if (conf->cluster_sync_high < sector_nr + nr_sectors) {
conf->cluster_sync_low = mddev->curr_resync_completed;
raid10_set_cluster_sync_high(conf);
/* Send resync message */
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
} else if (mddev_is_clustered(mddev)) {
/* This is recovery not resync */
sector_t sect_va1, sect_va2;
bool broadcast_msg = false;
for (i = 0; i < conf->geo.raid_disks; i++) {
/*
* sector_nr is a device address for recovery, so we
* need translate it to array address before compare
* with cluster_sync_high.
*/
sect_va1 = raid10_find_virt(conf, sector_nr, i);
if (conf->cluster_sync_high < sect_va1 + nr_sectors) {
broadcast_msg = true;
/*
* curr_resync_completed is similar as
* sector_nr, so make the translation too.
*/
sect_va2 = raid10_find_virt(conf,
mddev->curr_resync_completed, i);
if (conf->cluster_sync_low == 0 ||
conf->cluster_sync_low > sect_va2)
conf->cluster_sync_low = sect_va2;
}
}
if (broadcast_msg) {
raid10_set_cluster_sync_high(conf);
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
}
while (biolist) {
bio = biolist;
biolist = biolist->bi_next;
bio->bi_next = NULL;
r10_bio = get_resync_r10bio(bio);
r10_bio->sectors = nr_sectors;
if (bio->bi_end_io == end_sync_read) {
md_sync_acct_bio(bio, nr_sectors);
bio->bi_status = 0;
generic_make_request(bio);
}
}
if (sectors_skipped)
/* pretend they weren't skipped, it makes
* no important difference in this case
*/
md_done_sync(mddev, sectors_skipped, 1);
return sectors_skipped + nr_sectors;
giveup:
/* There is nowhere to write, so all non-sync
* drives must be failed or in resync, all drives
* have a bad block, so try the next chunk...
*/
if (sector_nr + max_sync < max_sector)
max_sector = sector_nr + max_sync;
sectors_skipped += (max_sector - sector_nr);
chunks_skipped ++;
sector_nr = max_sector;
goto skipped;
}
static sector_t
raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
sector_t size;
struct r10conf *conf = mddev->private;
if (!raid_disks)
raid_disks = min(conf->geo.raid_disks,
conf->prev.raid_disks);
if (!sectors)
sectors = conf->dev_sectors;
size = sectors >> conf->geo.chunk_shift;
sector_div(size, conf->geo.far_copies);
size = size * raid_disks;
sector_div(size, conf->geo.near_copies);
return size << conf->geo.chunk_shift;
}
static void calc_sectors(struct r10conf *conf, sector_t size)
{
/* Calculate the number of sectors-per-device that will
* actually be used, and set conf->dev_sectors and
* conf->stride
*/
size = size >> conf->geo.chunk_shift;
sector_div(size, conf->geo.far_copies);
size = size * conf->geo.raid_disks;
sector_div(size, conf->geo.near_copies);
/* 'size' is now the number of chunks in the array */
/* calculate "used chunks per device" */
size = size * conf->copies;
/* We need to round up when dividing by raid_disks to
* get the stride size.
*/
size = DIV_ROUND_UP_SECTOR_T(size, conf->geo.raid_disks);
conf->dev_sectors = size << conf->geo.chunk_shift;
if (conf->geo.far_offset)
conf->geo.stride = 1 << conf->geo.chunk_shift;
else {
sector_div(size, conf->geo.far_copies);
conf->geo.stride = size << conf->geo.chunk_shift;
}
}
enum geo_type {geo_new, geo_old, geo_start};
static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
{
int nc, fc, fo;
int layout, chunk, disks;
switch (new) {
case geo_old:
layout = mddev->layout;
chunk = mddev->chunk_sectors;
disks = mddev->raid_disks - mddev->delta_disks;
break;
case geo_new:
layout = mddev->new_layout;
chunk = mddev->new_chunk_sectors;
disks = mddev->raid_disks;
break;
default: /* avoid 'may be unused' warnings */
case geo_start: /* new when starting reshape - raid_disks not
* updated yet. */
layout = mddev->new_layout;
chunk = mddev->new_chunk_sectors;
disks = mddev->raid_disks + mddev->delta_disks;
break;
}
if (layout >> 19)
return -1;
if (chunk < (PAGE_SIZE >> 9) ||
!is_power_of_2(chunk))
return -2;
nc = layout & 255;
fc = (layout >> 8) & 255;
fo = layout & (1<<16);
geo->raid_disks = disks;
geo->near_copies = nc;
geo->far_copies = fc;
geo->far_offset = fo;
switch (layout >> 17) {
case 0: /* original layout. simple but not always optimal */
geo->far_set_size = disks;
break;
case 1: /* "improved" layout which was buggy. Hopefully no-one is
* actually using this, but leave code here just in case.*/
geo->far_set_size = disks/fc;
WARN(geo->far_set_size < fc,
"This RAID10 layout does not provide data safety - please backup and create new array\n");
break;
case 2: /* "improved" layout fixed to match documentation */
geo->far_set_size = fc * nc;
break;
default: /* Not a valid layout */
return -1;
}
geo->chunk_mask = chunk - 1;
geo->chunk_shift = ffz(~chunk);
return nc*fc;
}
static struct r10conf *setup_conf(struct mddev *mddev)
{
struct r10conf *conf = NULL;
int err = -EINVAL;
struct geom geo;
int copies;
copies = setup_geo(&geo, mddev, geo_new);
if (copies == -2) {
pr_warn("md/raid10:%s: chunk size must be at least PAGE_SIZE(%ld) and be a power of 2.\n",
mdname(mddev), PAGE_SIZE);
goto out;
}
if (copies < 2 || copies > mddev->raid_disks) {
pr_warn("md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
mdname(mddev), mddev->new_layout);
goto out;
}
err = -ENOMEM;
conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
if (!conf)
goto out;
/* FIXME calc properly */
conf->mirrors = kcalloc(mddev->raid_disks + max(0, -mddev->delta_disks),
sizeof(struct raid10_info),
GFP_KERNEL);
if (!conf->mirrors)
goto out;
conf->tmppage = alloc_page(GFP_KERNEL);
if (!conf->tmppage)
goto out;
conf->geo = geo;
conf->copies = copies;
err = mempool_init(&conf->r10bio_pool, NR_RAID_BIOS, r10bio_pool_alloc,
rbio_pool_free, conf);
if (err)
goto out;
err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
if (err)
goto out;
calc_sectors(conf, mddev->dev_sectors);
if (mddev->reshape_position == MaxSector) {
conf->prev = conf->geo;
conf->reshape_progress = MaxSector;
} else {
if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) {
err = -EINVAL;
goto out;
}
conf->reshape_progress = mddev->reshape_position;
if (conf->prev.far_offset)
conf->prev.stride = 1 << conf->prev.chunk_shift;
else
/* far_copies must be 1 */
conf->prev.stride = conf->dev_sectors;
}
conf->reshape_safe = conf->reshape_progress;
spin_lock_init(&conf->device_lock);
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);
atomic_set(&conf->nr_pending, 0);
err = -ENOMEM;
conf->thread = md_register_thread(raid10d, mddev, "raid10");
if (!conf->thread)
goto out;
conf->mddev = mddev;
return conf;
out:
if (conf) {
mempool_exit(&conf->r10bio_pool);
kfree(conf->mirrors);
safe_put_page(conf->tmppage);
bioset_exit(&conf->bio_split);
kfree(conf);
}
return ERR_PTR(err);
}
static int raid10_run(struct mddev *mddev)
{
struct r10conf *conf;
int i, disk_idx, chunk_size;
struct raid10_info *disk;
struct md_rdev *rdev;
sector_t size;
sector_t min_offset_diff = 0;
int first = 1;
bool discard_supported = false;
if (mddev_init_writes_pending(mddev) < 0)
return -ENOMEM;
if (mddev->private == NULL) {
conf = setup_conf(mddev);
if (IS_ERR(conf))
return PTR_ERR(conf);
mddev->private = conf;
}
conf = mddev->private;
if (!conf)
goto out;
if (mddev_is_clustered(conf->mddev)) {
int fc, fo;
fc = (mddev->layout >> 8) & 255;
fo = mddev->layout & (1<<16);
if (fc > 1 || fo > 0) {
pr_err("only near layout is supported by clustered"
" raid10\n");
goto out_free_conf;
}
}
mddev->thread = conf->thread;
conf->thread = NULL;
chunk_size = mddev->chunk_sectors << 9;
if (mddev->queue) {
blk_queue_max_discard_sectors(mddev->queue,
mddev->chunk_sectors);
blk_queue_max_write_same_sectors(mddev->queue, 0);
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
blk_queue_io_min(mddev->queue, chunk_size);
if (conf->geo.raid_disks % conf->geo.near_copies)
blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
else
blk_queue_io_opt(mddev->queue, chunk_size *
(conf->geo.raid_disks / conf->geo.near_copies));
}
rdev_for_each(rdev, mddev) {
long long diff;
disk_idx = rdev->raid_disk;
if (disk_idx < 0)
continue;
if (disk_idx >= conf->geo.raid_disks &&
disk_idx >= conf->prev.raid_disks)
continue;
disk = conf->mirrors + disk_idx;
if (test_bit(Replacement, &rdev->flags)) {
if (disk->replacement)
goto out_free_conf;
disk->replacement = rdev;
} else {
if (disk->rdev)
goto out_free_conf;
disk->rdev = rdev;
}
diff = (rdev->new_data_offset - rdev->data_offset);
if (!mddev->reshape_backwards)
diff = -diff;
if (diff < 0)
diff = 0;
if (first || diff < min_offset_diff)
min_offset_diff = diff;
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
disk->head_position = 0;
if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
discard_supported = true;
first = 0;
}
if (mddev->queue) {
if (discard_supported)
blk_queue_flag_set(QUEUE_FLAG_DISCARD,
mddev->queue);
else
blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
mddev->queue);
}
/* need to check that every block has at least one working mirror */
if (!enough(conf, -1)) {
pr_err("md/raid10:%s: not enough operational mirrors.\n",
mdname(mddev));
goto out_free_conf;
}
if (conf->reshape_progress != MaxSector) {
/* must ensure that shape change is supported */
if (conf->geo.far_copies != 1 &&
conf->geo.far_offset == 0)
goto out_free_conf;
if (conf->prev.far_copies != 1 &&
conf->prev.far_offset == 0)
goto out_free_conf;
}
mddev->degraded = 0;
for (i = 0;
i < conf->geo.raid_disks
|| i < conf->prev.raid_disks;
i++) {
disk = conf->mirrors + i;
if (!disk->rdev && disk->replacement) {
/* The replacement is all we have - use it */
disk->rdev = disk->replacement;
disk->replacement = NULL;
clear_bit(Replacement, &disk->rdev->flags);
}
if (!disk->rdev ||
!test_bit(In_sync, &disk->rdev->flags)) {
disk->head_position = 0;
mddev->degraded++;
if (disk->rdev &&
disk->rdev->saved_raid_disk < 0)
conf->fullsync = 1;
}
if (disk->replacement &&
!test_bit(In_sync, &disk->replacement->flags) &&
disk->replacement->saved_raid_disk < 0) {
conf->fullsync = 1;
}
disk->recovery_disabled = mddev->recovery_disabled - 1;
}
if (mddev->recovery_cp != MaxSector)
pr_notice("md/raid10:%s: not clean -- starting background reconstruction\n",
mdname(mddev));
pr_info("md/raid10:%s: active with %d out of %d devices\n",
mdname(mddev), conf->geo.raid_disks - mddev->degraded,
conf->geo.raid_disks);
/*
* Ok, everything is just fine now
*/
mddev->dev_sectors = conf->dev_sectors;
size = raid10_size(mddev, 0, 0);
md_set_array_sectors(mddev, size);
mddev->resync_max_sectors = size;
set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
if (mddev->queue) {
int stripe = conf->geo.raid_disks *
((mddev->chunk_sectors << 9) / PAGE_SIZE);
/* Calculate max read-ahead size.
* We need to readahead at least twice a whole stripe....
* maybe...
*/
stripe /= conf->geo.near_copies;
if (mddev->queue->backing_dev_info->ra_pages < 2 * stripe)
mddev->queue->backing_dev_info->ra_pages = 2 * stripe;
}
if (md_integrity_register(mddev))
goto out_free_conf;
if (conf->reshape_progress != MaxSector) {
unsigned long before_length, after_length;
before_length = ((1 << conf->prev.chunk_shift) *
conf->prev.far_copies);
after_length = ((1 << conf->geo.chunk_shift) *
conf->geo.far_copies);
if (max(before_length, after_length) > min_offset_diff) {
/* This cannot work */
pr_warn("md/raid10: offset difference not enough to continue reshape\n");
goto out_free_conf;
}
conf->offset_diff = min_offset_diff;
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
mddev->sync_thread = md_register_thread(md_do_sync, mddev,
"reshape");
if (!mddev->sync_thread)
goto out_free_conf;
}
return 0;
out_free_conf:
md_unregister_thread(&mddev->thread);
mempool_exit(&conf->r10bio_pool);
safe_put_page(conf->tmppage);
kfree(conf->mirrors);
kfree(conf);
mddev->private = NULL;
out:
return -EIO;
}
static void raid10_free(struct mddev *mddev, void *priv)
{
struct r10conf *conf = priv;
mempool_exit(&conf->r10bio_pool);
safe_put_page(conf->tmppage);
kfree(conf->mirrors);
kfree(conf->mirrors_old);
kfree(conf->mirrors_new);
bioset_exit(&conf->bio_split);
kfree(conf);
}
static void raid10_quiesce(struct mddev *mddev, int quiesce)
{
struct r10conf *conf = mddev->private;
if (quiesce)
raise_barrier(conf, 0);
else
lower_barrier(conf);
}
static int raid10_resize(struct mddev *mddev, sector_t sectors)
{
/* Resize of 'far' arrays is not supported.
* For 'near' and 'offset' arrays we can set the
* number of sectors used to be an appropriate multiple
* of the chunk size.
* For 'offset', this is far_copies*chunksize.
* For 'near' the multiplier is the LCM of
* near_copies and raid_disks.
* So if far_copies > 1 && !far_offset, fail.
* Else find LCM(raid_disks, near_copy)*far_copies and
* multiply by chunk_size. Then round to this number.
* This is mostly done by raid10_size()
*/
struct r10conf *conf = mddev->private;
sector_t oldsize, size;
if (mddev->reshape_position != MaxSector)
return -EBUSY;
if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
return -EINVAL;
oldsize = raid10_size(mddev, 0, 0);
size = raid10_size(mddev, sectors, 0);
if (mddev->external_size &&
mddev->array_sectors > size)
return -EINVAL;
if (mddev->bitmap) {
int ret = md_bitmap_resize(mddev->bitmap, size, 0, 0);
if (ret)
return ret;
}
md_set_array_sectors(mddev, size);
if (sectors > mddev->dev_sectors &&
mddev->recovery_cp > oldsize) {
mddev->recovery_cp = oldsize;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
calc_sectors(conf, sectors);
mddev->dev_sectors = conf->dev_sectors;
mddev->resync_max_sectors = size;
return 0;
}
static void *raid10_takeover_raid0(struct mddev *mddev, sector_t size, int devs)
{
struct md_rdev *rdev;
struct r10conf *conf;
if (mddev->degraded > 0) {
pr_warn("md/raid10:%s: Error: degraded raid0!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
sector_div(size, devs);
/* Set new parameters */
mddev->new_level = 10;
/* new layout: far_copies = 1, near_copies = 2 */
mddev->new_layout = (1<<8) + 2;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = mddev->raid_disks;
mddev->raid_disks *= 2;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev->dev_sectors = size;
conf = setup_conf(mddev);
if (!IS_ERR(conf)) {
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0) {
rdev->new_raid_disk = rdev->raid_disk * 2;
rdev->sectors = size;
}
conf->barrier = 1;
}
return conf;
}
static void *raid10_takeover(struct mddev *mddev)
{
struct r0conf *raid0_conf;
/* raid10 can take over:
* raid0 - providing it has only two drives
*/
if (mddev->level == 0) {
/* for raid0 takeover only one zone is supported */
raid0_conf = mddev->private;
if (raid0_conf->nr_strip_zones > 1) {
pr_warn("md/raid10:%s: cannot takeover raid 0 with more than one zone.\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
return raid10_takeover_raid0(mddev,
raid0_conf->strip_zone->zone_end,
raid0_conf->strip_zone->nb_dev);
}
return ERR_PTR(-EINVAL);
}
static int raid10_check_reshape(struct mddev *mddev)
{
/* Called when there is a request to change
* - layout (to ->new_layout)
* - chunk size (to ->new_chunk_sectors)
* - raid_disks (by delta_disks)
* or when trying to restart a reshape that was ongoing.
*
* We need to validate the request and possibly allocate
* space if that might be an issue later.
*
* Currently we reject any reshape of a 'far' mode array,
* allow chunk size to change if new is generally acceptable,
* allow raid_disks to increase, and allow
* a switch between 'near' mode and 'offset' mode.
*/
struct r10conf *conf = mddev->private;
struct geom geo;
if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
return -EINVAL;
if (setup_geo(&geo, mddev, geo_start) != conf->copies)
/* mustn't change number of copies */
return -EINVAL;
if (geo.far_copies > 1 && !geo.far_offset)
/* Cannot switch to 'far' mode */
return -EINVAL;
if (mddev->array_sectors & geo.chunk_mask)
/* not factor of array size */
return -EINVAL;
if (!enough(conf, -1))
return -EINVAL;
kfree(conf->mirrors_new);
conf->mirrors_new = NULL;
if (mddev->delta_disks > 0) {
/* allocate new 'mirrors' list */
conf->mirrors_new =
kcalloc(mddev->raid_disks + mddev->delta_disks,
sizeof(struct raid10_info),
GFP_KERNEL);
if (!conf->mirrors_new)
return -ENOMEM;
}
return 0;
}
/*
* Need to check if array has failed when deciding whether to:
* - start an array
* - remove non-faulty devices
* - add a spare
* - allow a reshape
* This determination is simple when no reshape is happening.
* However if there is a reshape, we need to carefully check
* both the before and after sections.
* This is because some failed devices may only affect one
* of the two sections, and some non-in_sync devices may
* be insync in the section most affected by failed devices.
*/
static int calc_degraded(struct r10conf *conf)
{
int degraded, degraded2;
int i;
rcu_read_lock();
degraded = 0;
/* 'prev' section first */
for (i = 0; i < conf->prev.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded++;
else if (!test_bit(In_sync, &rdev->flags))
/* When we can reduce the number of devices in
* an array, this might not contribute to
* 'degraded'. It does now.
*/
degraded++;
}
rcu_read_unlock();
if (conf->geo.raid_disks == conf->prev.raid_disks)
return degraded;
rcu_read_lock();
degraded2 = 0;
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded2++;
else if (!test_bit(In_sync, &rdev->flags)) {
/* If reshape is increasing the number of devices,
* this section has already been recovered, so
* it doesn't contribute to degraded.
* else it does.
*/
if (conf->geo.raid_disks <= conf->prev.raid_disks)
degraded2++;
}
}
rcu_read_unlock();
if (degraded2 > degraded)
return degraded2;
return degraded;
}
static int raid10_start_reshape(struct mddev *mddev)
{
/* A 'reshape' has been requested. This commits
* the various 'new' fields and sets MD_RECOVER_RESHAPE
* This also checks if there are enough spares and adds them
* to the array.
* We currently require enough spares to make the final
* array non-degraded. We also require that the difference
* between old and new data_offset - on each device - is
* enough that we never risk over-writing.
*/
unsigned long before_length, after_length;
sector_t min_offset_diff = 0;
int first = 1;
struct geom new;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
int spares = 0;
int ret;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;
if (setup_geo(&new, mddev, geo_start) != conf->copies)
return -EINVAL;
before_length = ((1 << conf->prev.chunk_shift) *
conf->prev.far_copies);
after_length = ((1 << conf->geo.chunk_shift) *
conf->geo.far_copies);
rdev_for_each(rdev, mddev) {
if (!test_bit(In_sync, &rdev->flags)
&& !test_bit(Faulty, &rdev->flags))
spares++;
if (rdev->raid_disk >= 0) {
long long diff = (rdev->new_data_offset
- rdev->data_offset);
if (!mddev->reshape_backwards)
diff = -diff;
if (diff < 0)
diff = 0;
if (first || diff < min_offset_diff)
min_offset_diff = diff;
first = 0;
}
}
if (max(before_length, after_length) > min_offset_diff)
return -EINVAL;
if (spares < mddev->delta_disks)
return -EINVAL;
conf->offset_diff = min_offset_diff;
spin_lock_irq(&conf->device_lock);
if (conf->mirrors_new) {
memcpy(conf->mirrors_new, conf->mirrors,
sizeof(struct raid10_info)*conf->prev.raid_disks);
smp_mb();
kfree(conf->mirrors_old);
conf->mirrors_old = conf->mirrors;
conf->mirrors = conf->mirrors_new;
conf->mirrors_new = NULL;
}
setup_geo(&conf->geo, mddev, geo_start);
smp_mb();
if (mddev->reshape_backwards) {
sector_t size = raid10_size(mddev, 0, 0);
if (size < mddev->array_sectors) {
spin_unlock_irq(&conf->device_lock);
pr_warn("md/raid10:%s: array size must be reduce before number of disks\n",
mdname(mddev));
return -EINVAL;
}
mddev->resync_max_sectors = size;
conf->reshape_progress = size;
} else
conf->reshape_progress = 0;
conf->reshape_safe = conf->reshape_progress;
spin_unlock_irq(&conf->device_lock);
if (mddev->delta_disks && mddev->bitmap) {
struct mdp_superblock_1 *sb = NULL;
sector_t oldsize, newsize;
oldsize = raid10_size(mddev, 0, 0);
newsize = raid10_size(mddev, 0, conf->geo.raid_disks);
if (!mddev_is_clustered(mddev)) {
ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
goto abort;
else
goto out;
}
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk > -1 &&
!test_bit(Faulty, &rdev->flags))
sb = page_address(rdev->sb_page);
}
/*
* some node is already performing reshape, and no need to
* call md_bitmap_resize again since it should be called when
* receiving BITMAP_RESIZE msg
*/
if ((sb && (le32_to_cpu(sb->feature_map) &
MD_FEATURE_RESHAPE_ACTIVE)) || (oldsize == newsize))
goto out;
ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
goto abort;
ret = md_cluster_ops->resize_bitmaps(mddev, newsize, oldsize);
if (ret) {
md_bitmap_resize(mddev->bitmap, oldsize, 0, 0);
goto abort;
}
}
out:
if (mddev->delta_disks > 0) {
rdev_for_each(rdev, mddev)
if (rdev->raid_disk < 0 &&
!test_bit(Faulty, &rdev->flags)) {
if (raid10_add_disk(mddev, rdev) == 0) {
if (rdev->raid_disk >=
conf->prev.raid_disks)
set_bit(In_sync, &rdev->flags);
else
rdev->recovery_offset = 0;
if (sysfs_link_rdev(mddev, rdev))
/* Failure here is OK */;
}
} else if (rdev->raid_disk >= conf->prev.raid_disks
&& !test_bit(Faulty, &rdev->flags)) {
/* This is a spare that was manually added */
set_bit(In_sync, &rdev->flags);
}
}
/* When a reshape changes the number of devices,
* ->degraded is measured against the larger of the
* pre and post numbers.
*/
spin_lock_irq(&conf->device_lock);
mddev->degraded = calc_degraded(conf);
spin_unlock_irq(&conf->device_lock);
mddev->raid_disks = conf->geo.raid_disks;
mddev->reshape_position = conf->reshape_progress;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
mddev->sync_thread = md_register_thread(md_do_sync, mddev,
"reshape");
if (!mddev->sync_thread) {
ret = -EAGAIN;
goto abort;
}
conf->reshape_checkpoint = jiffies;
md_wakeup_thread(mddev->sync_thread);
md_new_event(mddev);
return 0;
abort:
mddev->recovery = 0;
spin_lock_irq(&conf->device_lock);
conf->geo = conf->prev;
mddev->raid_disks = conf->geo.raid_disks;
rdev_for_each(rdev, mddev)
rdev->new_data_offset = rdev->data_offset;
smp_wmb();
conf->reshape_progress = MaxSector;
conf->reshape_safe = MaxSector;
mddev->reshape_position = MaxSector;
spin_unlock_irq(&conf->device_lock);
return ret;
}
/* Calculate the last device-address that could contain
* any block from the chunk that includes the array-address 's'
* and report the next address.
* i.e. the address returned will be chunk-aligned and after
* any data that is in the chunk containing 's'.
*/
static sector_t last_dev_address(sector_t s, struct geom *geo)
{
s = (s | geo->chunk_mask) + 1;
s >>= geo->chunk_shift;
s *= geo->near_copies;
s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks);
s *= geo->far_copies;
s <<= geo->chunk_shift;
return s;
}
/* Calculate the first device-address that could contain
* any block from the chunk that includes the array-address 's'.
* This too will be the start of a chunk
*/
static sector_t first_dev_address(sector_t s, struct geom *geo)
{
s >>= geo->chunk_shift;
s *= geo->near_copies;
sector_div(s, geo->raid_disks);
s *= geo->far_copies;
s <<= geo->chunk_shift;
return s;
}
static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
/* We simply copy at most one chunk (smallest of old and new)
* at a time, possibly less if that exceeds RESYNC_PAGES,
* or we hit a bad block or something.
* This might mean we pause for normal IO in the middle of
* a chunk, but that is not a problem as mddev->reshape_position
* can record any location.
*
* If we will want to write to a location that isn't
* yet recorded as 'safe' (i.e. in metadata on disk) then
* we need to flush all reshape requests and update the metadata.
*
* When reshaping forwards (e.g. to more devices), we interpret
* 'safe' as the earliest block which might not have been copied
* down yet. We divide this by previous stripe size and multiply
* by previous stripe length to get lowest device offset that we
* cannot write to yet.
* We interpret 'sector_nr' as an address that we want to write to.
* From this we use last_device_address() to find where we might
* write to, and first_device_address on the 'safe' position.
* If this 'next' write position is after the 'safe' position,
* we must update the metadata to increase the 'safe' position.
*
* When reshaping backwards, we round in the opposite direction
* and perform the reverse test: next write position must not be
* less than current safe position.
*
* In all this the minimum difference in data offsets
* (conf->offset_diff - always positive) allows a bit of slack,
* so next can be after 'safe', but not by more than offset_diff
*
* We need to prepare all the bios here before we start any IO
* to ensure the size we choose is acceptable to all devices.
* The means one for each copy for write-out and an extra one for
* read-in.
* We store the read-in bio in ->master_bio and the others in
* ->devs[x].bio and ->devs[x].repl_bio.
*/
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
sector_t next, safe, last;
int max_sectors;
int nr_sectors;
int s;
struct md_rdev *rdev;
int need_flush = 0;
struct bio *blist;
struct bio *bio, *read_bio;
int sectors_done = 0;
struct page **pages;
if (sector_nr == 0) {
/* If restarting in the middle, skip the initial sectors */
if (mddev->reshape_backwards &&
conf->reshape_progress < raid10_size(mddev, 0, 0)) {
sector_nr = (raid10_size(mddev, 0, 0)
- conf->reshape_progress);
} else if (!mddev->reshape_backwards &&
conf->reshape_progress > 0)
sector_nr = conf->reshape_progress;
if (sector_nr) {
mddev->curr_resync_completed = sector_nr;
sysfs_notify(&mddev->kobj, NULL, "sync_completed");
*skipped = 1;
return sector_nr;
}
}
/* We don't use sector_nr to track where we are up to
* as that doesn't work well for ->reshape_backwards.
* So just use ->reshape_progress.
*/
if (mddev->reshape_backwards) {
/* 'next' is the earliest device address that we might
* write to for this chunk in the new layout
*/
next = first_dev_address(conf->reshape_progress - 1,
&conf->geo);
/* 'safe' is the last device address that we might read from
* in the old layout after a restart
*/
safe = last_dev_address(conf->reshape_safe - 1,
&conf->prev);
if (next + conf->offset_diff < safe)
need_flush = 1;
last = conf->reshape_progress - 1;
sector_nr = last & ~(sector_t)(conf->geo.chunk_mask
& conf->prev.chunk_mask);
if (sector_nr + RESYNC_BLOCK_SIZE/512 < last)
sector_nr = last + 1 - RESYNC_BLOCK_SIZE/512;
} else {
/* 'next' is after the last device address that we
* might write to for this chunk in the new layout
*/
next = last_dev_address(conf->reshape_progress, &conf->geo);
/* 'safe' is the earliest device address that we might
* read from in the old layout after a restart
*/
safe = first_dev_address(conf->reshape_safe, &conf->prev);
/* Need to update metadata if 'next' might be beyond 'safe'
* as that would possibly corrupt data
*/
if (next > safe + conf->offset_diff)
need_flush = 1;
sector_nr = conf->reshape_progress;
last = sector_nr | (conf->geo.chunk_mask
& conf->prev.chunk_mask);
if (sector_nr + RESYNC_BLOCK_SIZE/512 <= last)
last = sector_nr + RESYNC_BLOCK_SIZE/512 - 1;
}
if (need_flush ||
time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
/* Need to update reshape_position in metadata */
wait_barrier(conf);
mddev->reshape_position = conf->reshape_progress;
if (mddev->reshape_backwards)
mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
- conf->reshape_progress;
else
mddev->curr_resync_completed = conf->reshape_progress;
conf->reshape_checkpoint = jiffies;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
wait_event(mddev->sb_wait, mddev->sb_flags == 0 ||
test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
allow_barrier(conf);
return sectors_done;
}
conf->reshape_safe = mddev->reshape_position;
allow_barrier(conf);
}
raise_barrier(conf, 0);
read_more:
/* Now schedule reads for blocks from sector_nr to last */
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
raise_barrier(conf, 1);
atomic_set(&r10_bio->remaining, 0);
r10_bio->mddev = mddev;
r10_bio->sector = sector_nr;
set_bit(R10BIO_IsReshape, &r10_bio->state);
r10_bio->sectors = last - sector_nr + 1;
rdev = read_balance(conf, r10_bio, &max_sectors);
BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state));
if (!rdev) {
/* Cannot read from here, so need to record bad blocks
* on all the target devices.
*/
// FIXME
mempool_free(r10_bio, &conf->r10buf_pool);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return sectors_done;
}
read_bio = bio_alloc_mddev(GFP_KERNEL, RESYNC_PAGES, mddev);
bio_set_dev(read_bio, rdev->bdev);
read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
+ rdev->data_offset);
read_bio->bi_private = r10_bio;
read_bio->bi_end_io = end_reshape_read;
bio_set_op_attrs(read_bio, REQ_OP_READ, 0);
read_bio->bi_flags &= (~0UL << BIO_RESET_BITS);
read_bio->bi_status = 0;
read_bio->bi_vcnt = 0;
read_bio->bi_iter.bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
/*
* Broadcast RESYNC message to other nodes, so all nodes would not
* write to the region to avoid conflict.
*/
if (mddev_is_clustered(mddev) && conf->cluster_sync_high <= sector_nr) {
struct mdp_superblock_1 *sb = NULL;
int sb_reshape_pos = 0;
conf->cluster_sync_low = sector_nr;
conf->cluster_sync_high = sector_nr + CLUSTER_RESYNC_WINDOW_SECTORS;
sb = page_address(rdev->sb_page);
if (sb) {
sb_reshape_pos = le64_to_cpu(sb->reshape_position);
/*
* Set cluster_sync_low again if next address for array
* reshape is less than cluster_sync_low. Since we can't
* update cluster_sync_low until it has finished reshape.
*/
if (sb_reshape_pos < conf->cluster_sync_low)
conf->cluster_sync_low = sb_reshape_pos;
}
md_cluster_ops->resync_info_update(mddev, conf->cluster_sync_low,
conf->cluster_sync_high);
}
/* Now find the locations in the new layout */
__raid10_find_phys(&conf->geo, r10_bio);
blist = read_bio;
read_bio->bi_next = NULL;
rcu_read_lock();
for (s = 0; s < conf->copies*2; s++) {
struct bio *b;
int d = r10_bio->devs[s/2].devnum;
struct md_rdev *rdev2;
if (s&1) {
rdev2 = rcu_dereference(conf->mirrors[d].replacement);
b = r10_bio->devs[s/2].repl_bio;
} else {
rdev2 = rcu_dereference(conf->mirrors[d].rdev);
b = r10_bio->devs[s/2].bio;
}
if (!rdev2 || test_bit(Faulty, &rdev2->flags))
continue;
bio_set_dev(b, rdev2->bdev);
b->bi_iter.bi_sector = r10_bio->devs[s/2].addr +
rdev2->new_data_offset;
b->bi_end_io = end_reshape_write;
bio_set_op_attrs(b, REQ_OP_WRITE, 0);
b->bi_next = blist;
blist = b;
}
/* Now add as many pages as possible to all of these bios. */
nr_sectors = 0;
pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
struct page *page = pages[s / (PAGE_SIZE >> 9)];
int len = (max_sectors - s) << 9;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
for (bio = blist; bio ; bio = bio->bi_next) {
/*
* won't fail because the vec table is big enough
* to hold all these pages
*/
bio_add_page(bio, page, len, 0);
}
sector_nr += len >> 9;
nr_sectors += len >> 9;
}
rcu_read_unlock();
r10_bio->sectors = nr_sectors;
/* Now submit the read */
md_sync_acct_bio(read_bio, r10_bio->sectors);
atomic_inc(&r10_bio->remaining);
read_bio->bi_next = NULL;
generic_make_request(read_bio);
sectors_done += nr_sectors;
if (sector_nr <= last)
goto read_more;
lower_barrier(conf);
/* Now that we have done the whole section we can
* update reshape_progress
*/
if (mddev->reshape_backwards)
conf->reshape_progress -= sectors_done;
else
conf->reshape_progress += sectors_done;
return sectors_done;
}
static void end_reshape_request(struct r10bio *r10_bio);
static int handle_reshape_read_error(struct mddev *mddev,
struct r10bio *r10_bio);
static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
/* Reshape read completed. Hopefully we have a block
* to write out.
* If we got a read error then we do sync 1-page reads from
* elsewhere until we find the data - or give up.
*/
struct r10conf *conf = mddev->private;
int s;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
if (handle_reshape_read_error(mddev, r10_bio) < 0) {
/* Reshape has been aborted */
md_done_sync(mddev, r10_bio->sectors, 0);
return;
}
/* We definitely have the data in the pages, schedule the
* writes.
*/
atomic_set(&r10_bio->remaining, 1);
for (s = 0; s < conf->copies*2; s++) {
struct bio *b;
int d = r10_bio->devs[s/2].devnum;
struct md_rdev *rdev;
rcu_read_lock();
if (s&1) {
rdev = rcu_dereference(conf->mirrors[d].replacement);
b = r10_bio->devs[s/2].repl_bio;
} else {
rdev = rcu_dereference(conf->mirrors[d].rdev);
b = r10_bio->devs[s/2].bio;
}
if (!rdev || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
md_sync_acct_bio(b, r10_bio->sectors);
atomic_inc(&r10_bio->remaining);
b->bi_next = NULL;
generic_make_request(b);
}
end_reshape_request(r10_bio);
}
static void end_reshape(struct r10conf *conf)
{
if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery))
return;
spin_lock_irq(&conf->device_lock);
conf->prev = conf->geo;
md_finish_reshape(conf->mddev);
smp_wmb();
conf->reshape_progress = MaxSector;
conf->reshape_safe = MaxSector;
spin_unlock_irq(&conf->device_lock);
/* read-ahead size must cover two whole stripes, which is
* 2 * (datadisks) * chunksize where 'n' is the number of raid devices
*/
if (conf->mddev->queue) {
int stripe = conf->geo.raid_disks *
((conf->mddev->chunk_sectors << 9) / PAGE_SIZE);
stripe /= conf->geo.near_copies;
if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe)
conf->mddev->queue->backing_dev_info->ra_pages = 2 * stripe;
}
conf->fullsync = 0;
}
static void raid10_update_reshape_pos(struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
sector_t lo, hi;
md_cluster_ops->resync_info_get(mddev, &lo, &hi);
if (((mddev->reshape_position <= hi) && (mddev->reshape_position >= lo))
|| mddev->reshape_position == MaxSector)
conf->reshape_progress = mddev->reshape_position;
else
WARN_ON_ONCE(1);
}
static int handle_reshape_read_error(struct mddev *mddev,
struct r10bio *r10_bio)
{
/* Use sync reads to get the blocks from somewhere else */
int sectors = r10_bio->sectors;
struct r10conf *conf = mddev->private;
struct r10bio *r10b;
int slot = 0;
int idx = 0;
struct page **pages;
r10b = kmalloc(struct_size(r10b, devs, conf->copies), GFP_NOIO);
if (!r10b) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return -ENOMEM;
}
/* reshape IOs share pages from .devs[0].bio */
pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
r10b->sector = r10_bio->sector;
__raid10_find_phys(&conf->prev, r10b);
while (sectors) {
int s = sectors;
int success = 0;
int first_slot = slot;
if (s > (PAGE_SIZE >> 9))
s = PAGE_SIZE >> 9;
rcu_read_lock();
while (!success) {
int d = r10b->devs[slot].devnum;
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
sector_t addr;
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
goto failed;
addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
success = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_READ, 0, false);
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
if (success)
break;
failed:
slot++;
if (slot >= conf->copies)
slot = 0;
if (slot == first_slot)
break;
}
rcu_read_unlock();
if (!success) {
/* couldn't read this block, must give up */
set_bit(MD_RECOVERY_INTR,
&mddev->recovery);
kfree(r10b);
return -EIO;
}
sectors -= s;
idx++;
}
kfree(r10b);
return 0;
}
static void end_reshape_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;
if (!rdev) {
smp_mb();
rdev = conf->mirrors[d].rdev;
}
if (bio->bi_status) {
/* FIXME should record badblock */
md_error(mddev, rdev);
}
rdev_dec_pending(rdev, mddev);
end_reshape_request(r10_bio);
}
static void end_reshape_request(struct r10bio *r10_bio)
{
if (!atomic_dec_and_test(&r10_bio->remaining))
return;
md_done_sync(r10_bio->mddev, r10_bio->sectors, 1);
bio_put(r10_bio->master_bio);
put_buf(r10_bio);
}
static void raid10_finish_reshape(struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
return;
if (mddev->delta_disks > 0) {
if (mddev->recovery_cp > mddev->resync_max_sectors) {
mddev->recovery_cp = mddev->resync_max_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
mddev->resync_max_sectors = mddev->array_sectors;
} else {
int d;
rcu_read_lock();
for (d = conf->geo.raid_disks ;
d < conf->geo.raid_disks - mddev->delta_disks;
d++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev)
clear_bit(In_sync, &rdev->flags);
rdev = rcu_dereference(conf->mirrors[d].replacement);
if (rdev)
clear_bit(In_sync, &rdev->flags);
}
rcu_read_unlock();
}
mddev->layout = mddev->new_layout;
mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
mddev->reshape_position = MaxSector;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
}
static struct md_personality raid10_personality =
{
.name = "raid10",
.level = 10,
.owner = THIS_MODULE,
.make_request = raid10_make_request,
.run = raid10_run,
.free = raid10_free,
.status = raid10_status,
.error_handler = raid10_error,
.hot_add_disk = raid10_add_disk,
.hot_remove_disk= raid10_remove_disk,
.spare_active = raid10_spare_active,
.sync_request = raid10_sync_request,
.quiesce = raid10_quiesce,
.size = raid10_size,
.resize = raid10_resize,
.takeover = raid10_takeover,
.check_reshape = raid10_check_reshape,
.start_reshape = raid10_start_reshape,
.finish_reshape = raid10_finish_reshape,
.update_reshape_pos = raid10_update_reshape_pos,
.congested = raid10_congested,
};
static int __init raid_init(void)
{
return register_md_personality(&raid10_personality);
}
static void raid_exit(void)
{
unregister_md_personality(&raid10_personality);
}
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
MODULE_ALIAS("md-personality-9"); /* RAID10 */
MODULE_ALIAS("md-raid10");
MODULE_ALIAS("md-level-10");
module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
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