/drivers/md/raid10.c
C | 1752 lines | 1190 code | 172 blank | 390 comment | 236 complexity | be3daff5c92afcc342f88c2a0cd76729 MD5 | raw file
- /*
- * 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.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * You should have received a copy of the GNU General Public License
- * (for example /usr/src/linux/COPYING); if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #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 "md.h"
- #include "raid10.h"
- #include "raid0.h"
- #include "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]
- */
- /*
- * Number of guaranteed r10bios in case of extreme VM load:
- */
- #define NR_RAID10_BIOS 256
- /* when we get a read error on a read-only array, we redirect to another
- * device without failing the first device, or trying to over-write to
- * correct the read error. To keep track of bad blocks on a per-bio
- * level, we store IO_BLOCKED in the appropriate 'bios' pointer
- */
- #define IO_BLOCKED ((struct bio *)1)
- /* When we successfully write to a known bad-block, we need to remove the
- * bad-block marking which must be done from process context. So we record
- * the success by setting devs[n].bio to IO_MADE_GOOD
- */
- #define IO_MADE_GOOD ((struct bio *)2)
- #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
- /* When there are this many requests queued to be written by
- * the raid10 thread, we become 'congested' to provide back-pressure
- * for writeback.
- */
- static int max_queued_requests = 1024;
- 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 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);
- 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);
- }
- static void r10bio_pool_free(void *r10_bio, void *data)
- {
- kfree(r10_bio);
- }
- /* Maximum size of each resync request */
- #define RESYNC_BLOCK_SIZE (64*1024)
- #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
- /* 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)
- /*
- * 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 page *page;
- struct r10bio *r10_bio;
- struct bio *bio;
- int i, j;
- int nalloc;
- 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 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;
- bio = r10_bio->devs[j].bio;
- for (i = 0; i < RESYNC_PAGES; i++) {
- if (j > 0 && !test_bit(MD_RECOVERY_SYNC,
- &conf->mddev->recovery)) {
- /* we can share bv_page's during recovery
- * and reshape */
- struct bio *rbio = r10_bio->devs[0].bio;
- page = rbio->bi_io_vec[i].bv_page;
- get_page(page);
- } else
- page = alloc_page(gfp_flags);
- if (unlikely(!page))
- goto out_free_pages;
- bio->bi_io_vec[i].bv_page = page;
- if (rbio)
- rbio->bi_io_vec[i].bv_page = page;
- }
- }
- return r10_bio;
- out_free_pages:
- for ( ; i > 0 ; i--)
- safe_put_page(bio->bi_io_vec[i-1].bv_page);
- while (j--)
- for (i = 0; i < RESYNC_PAGES ; i++)
- safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
- 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);
- }
- r10bio_pool_free(r10_bio, conf);
- return NULL;
- }
- static void r10buf_pool_free(void *__r10_bio, void *data)
- {
- int i;
- struct r10conf *conf = data;
- struct r10bio *r10bio = __r10_bio;
- int j;
- for (j=0; j < conf->copies; j++) {
- struct bio *bio = r10bio->devs[j].bio;
- if (bio) {
- for (i = 0; i < RESYNC_PAGES; i++) {
- safe_put_page(bio->bi_io_vec[i].bv_page);
- bio->bi_io_vec[i].bv_page = NULL;
- }
- bio_put(bio);
- }
- bio = r10bio->devs[j].repl_bio;
- if (bio)
- bio_put(bio);
- }
- r10bio_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;
- int done;
- struct r10conf *conf = r10_bio->mddev->private;
- if (bio->bi_phys_segments) {
- unsigned long flags;
- spin_lock_irqsave(&conf->device_lock, flags);
- bio->bi_phys_segments--;
- done = (bio->bi_phys_segments == 0);
- spin_unlock_irqrestore(&conf->device_lock, flags);
- } else
- done = 1;
- if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
- bio->bi_error = -EIO;
- if (done) {
- 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_error;
- struct r10bio *r10_bio = bio->bi_private;
- int slot, dev;
- struct md_rdev *rdev;
- struct r10conf *conf = r10_bio->mddev->private;
- slot = r10_bio->read_slot;
- dev = r10_bio->devs[slot].devnum;
- 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];
- printk_ratelimited(KERN_ERR
- "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 */
- 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;
- 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_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);
- set_bit(R10BIO_WriteError, &r10_bio->state);
- dec_rdev = 0;
- }
- } 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)) {
- 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);
- }
- /*
- * 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_rdev, *rdev = NULL;
- int do_balance;
- int best_slot;
- struct geom *geo = &conf->geo;
- raid10_find_phys(conf, r10_bio);
- rcu_read_lock();
- retry:
- sectors = r10_bio->sectors;
- best_slot = -1;
- best_rdev = NULL;
- best_dist = MaxSector;
- best_good_sectors = 0;
- do_balance = 1;
- /*
- * 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))
- do_balance = 0;
- for (slot = 0; slot < conf->copies ; slot++) {
- sector_t first_bad;
- int bad_sectors;
- sector_t dev_sector;
- 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_slot = slot;
- best_rdev = rdev;
- }
- if (!do_balance)
- /* Must read from here */
- break;
- }
- continue;
- } else
- best_good_sectors = sectors;
- if (!do_balance)
- break;
- /* 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 && !atomic_read(&rdev->nr_pending))
- break;
- /* for far > 1 always use the lowest address */
- 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_slot = slot;
- best_rdev = rdev;
- }
- }
- if (slot >= conf->copies) {
- slot = best_slot;
- rdev = best_rdev;
- }
- if (slot >= 0) {
- atomic_inc(&rdev->nr_pending);
- if (test_bit(Faulty, &rdev->flags)) {
- /* Cannot risk returning a device that failed
- * before we inc'ed nr_pending
- */
- rdev_dec_pending(rdev, conf->mddev);
- goto retry;
- }
- 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 bio *bio;
- bio = bio_list_get(&conf->pending_bio_list);
- conf->pending_count = 0;
- spin_unlock_irq(&conf->device_lock);
- /* flush any pending bitmap writes to disk
- * before proceeding w/ I/O */
- bitmap_unplug(conf->mddev->bitmap);
- wake_up(&conf->wait_barrier);
- while (bio) { /* submit pending writes */
- struct bio *next = bio->bi_next;
- bio->bi_next = NULL;
- if (unlikely((bio->bi_rw & REQ_DISCARD) &&
- !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
- /* Just ignore it */
- bio_endio(bio);
- else
- generic_make_request(bio);
- bio = next;
- }
- } 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,
- !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.
- */
- wait_event_lock_irq(conf->wait_barrier,
- !conf->barrier ||
- (conf->nr_pending &&
- current->bio_list &&
- !bio_list_empty(current->bio_list)),
- conf->resync_lock);
- conf->nr_waiting--;
- }
- conf->nr_pending++;
- spin_unlock_irq(&conf->resync_lock);
- }
- static void allow_barrier(struct r10conf *conf)
- {
- unsigned long flags;
- spin_lock_irqsave(&conf->resync_lock, flags);
- conf->nr_pending--;
- spin_unlock_irqrestore(&conf->resync_lock, flags);
- 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->barrier++;
- conf->nr_waiting++;
- wait_event_lock_irq_cmd(conf->wait_barrier,
- conf->nr_pending == conf->nr_queued+extra,
- conf->resync_lock,
- flush_pending_writes(conf));
- 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);
- bitmap_unplug(mddev->bitmap);
- wake_up(&conf->wait_barrier);
- while (bio) { /* submit pending writes */
- struct bio *next = bio->bi_next;
- bio->bi_next = NULL;
- if (unlikely((bio->bi_rw & REQ_DISCARD) &&
- !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
- /* Just ignore it */
- bio_endio(bio);
- else
- generic_make_request(bio);
- bio = next;
- }
- kfree(plug);
- }
- static void __make_request(struct mddev *mddev, struct bio *bio)
- {
- struct r10conf *conf = mddev->private;
- struct r10bio *r10_bio;
- struct bio *read_bio;
- int i;
- const int rw = bio_data_dir(bio);
- const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
- const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
- const unsigned long do_discard = (bio->bi_rw
- & (REQ_DISCARD | REQ_SECURE));
- const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
- unsigned long flags;
- struct md_rdev *blocked_rdev;
- struct blk_plug_cb *cb;
- struct raid10_plug_cb *plug = NULL;
- int sectors_handled;
- int max_sectors;
- int sectors;
- /*
- * Register the new request and wait if the reconstruction
- * thread has put up a bar for new requests.
- * Continue immediately if no resync is active currently.
- */
- wait_barrier(conf);
- sectors = bio_sectors(bio);
- 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) {
- /* IO spans the reshape position. Need to wait for
- * reshape to pass
- */
- 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);
- }
- if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
- bio_data_dir(bio) == WRITE &&
- (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->flags, 0,
- BIT(MD_CHANGE_DEVS) | BIT(MD_CHANGE_PENDING));
- md_wakeup_thread(mddev->thread);
- wait_event(mddev->sb_wait,
- !test_bit(MD_CHANGE_PENDING, &mddev->flags));
- conf->reshape_safe = mddev->reshape_position;
- }
- 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;
- /* We might need to issue multiple reads to different
- * devices if there are bad blocks around, so we keep
- * track of the number of reads in bio->bi_phys_segments.
- * If this is 0, there is only one r10_bio and no locking
- * will be needed when the request completes. If it is
- * non-zero, then it is the number of not-completed requests.
- */
- bio->bi_phys_segments = 0;
- bio_clear_flag(bio, BIO_SEG_VALID);
- if (rw == READ) {
- /*
- * read balancing logic:
- */
- struct md_rdev *rdev;
- int slot;
- read_again:
- rdev = read_balance(conf, r10_bio, &max_sectors);
- if (!rdev) {
- raid_end_bio_io(r10_bio);
- return;
- }
- slot = r10_bio->read_slot;
- read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- bio_trim(read_bio, r10_bio->sector - bio->bi_iter.bi_sector,
- max_sectors);
- r10_bio->devs[slot].bio = read_bio;
- r10_bio->devs[slot].rdev = rdev;
- read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr +
- choose_data_offset(r10_bio, rdev);
- read_bio->bi_bdev = rdev->bdev;
- read_bio->bi_end_io = raid10_end_read_request;
- read_bio->bi_rw = READ | do_sync;
- read_bio->bi_private = r10_bio;
- if (max_sectors < r10_bio->sectors) {
- /* Could not read all from this device, so we will
- * need another r10_bio.
- */
- sectors_handled = (r10_bio->sector + max_sectors
- - bio->bi_iter.bi_sector);
- r10_bio->sectors = max_sectors;
- spin_lock_irq(&conf->device_lock);
- if (bio->bi_phys_segments == 0)
- bio->bi_phys_segments = 2;
- else
- bio->bi_phys_segments++;
- spin_unlock_irq(&conf->device_lock);
- /* Cannot call generic_make_request directly
- * as that will be queued in __generic_make_request
- * and subsequent mempool_alloc might block
- * waiting for it. so hand bio over to raid10d.
- */
- reschedule_retry(r10_bio);
- r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
- r10_bio->master_bio = bio;
- r10_bio->sectors = bio_sectors(bio) - sectors_handled;
- r10_bio->state = 0;
- r10_bio->mddev = mddev;
- r10_bio->sector = bio->bi_iter.bi_sector +
- sectors_handled;
- goto read_again;
- } else
- generic_make_request(read_bio);
- return;
- }
- /*
- * WRITE:
- */
- if (conf->pending_count >= max_queued_requests) {
- md_wakeup_thread(mddev->thread);
- 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. The number
- * of r10_bios is recored in bio->bi_phys_segments just as with
- * the read case.
- */
- 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);
- md_wait_for_blocked_rdev(blocked_rdev, mddev);
- wait_barrier(conf);
- goto retry_write;
- }
- if (max_sectors < r10_bio->sectors) {
- /* We are splitting this into multiple parts, so
- * we need to prepare for allocating another r10_bio.
- */
- r10_bio->sectors = max_sectors;
- spin_lock_irq(&conf->device_lock);
- if (bio->bi_phys_segments == 0)
- bio->bi_phys_segments = 2;
- else
- bio->bi_phys_segments++;
- spin_unlock_irq(&conf->device_lock);
- }
- sectors_handled = r10_bio->sector + max_sectors -
- bio->bi_iter.bi_sector;
- atomic_set(&r10_bio->remaining, 1);
- bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
- for (i = 0; i < conf->copies; i++) {
- struct bio *mbio;
- int d = r10_bio->devs[i].devnum;
- if (r10_bio->devs[i].bio) {
- struct md_rdev *rdev = conf->mirrors[d].rdev;
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector,
- max_sectors);
- r10_bio->devs[i].bio = mbio;
- mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr+
- choose_data_offset(r10_bio,
- rdev));
- mbio->bi_bdev = rdev->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw =
- WRITE | do_sync | do_fua | do_discard | do_same;
- mbio->bi_private = r10_bio;
- 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;
- spin_lock_irqsave(&conf->device_lock, flags);
- if (plug) {
- bio_list_add(&plug->pending, mbio);
- plug->pending_cnt++;
- } else {
- bio_list_add(&conf->pending_bio_list, mbio);
- conf->pending_count++;
- }
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (!plug)
- md_wakeup_thread(mddev->thread);
- }
- if (r10_bio->devs[i].repl_bio) {
- struct md_rdev *rdev = conf->mirrors[d].replacement;
- if (rdev == NULL) {
- /* Replacement just got moved to main 'rdev' */
- smp_mb();
- rdev = conf->mirrors[d].rdev;
- }
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector,
- max_sectors);
- r10_bio->devs[i].repl_bio = mbio;
- mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr +
- choose_data_offset(
- r10_bio, rdev));
- mbio->bi_bdev = rdev->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw =
- WRITE | do_sync | do_fua | do_discard | do_same;
- mbio->bi_private = r10_bio;
- atomic_inc(&r10_bio->remaining);
- 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);
- if (!mddev_check_plugged(mddev))
- md_wakeup_thread(mddev->thread);
- }
- }
- /* Don't remove the bias on 'remaining' (one_write_done) until
- * after checking if we need to go around again.
- */
- if (sectors_handled < bio_sectors(bio)) {
- one_write_done(r10_bio);
- /* We need another r10_bio. It has already been counted
- * in bio->bi_phys_segments.
- */
- r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
- r10_bio->master_bio = bio;
- r10_bio->sectors = bio_sectors(bio) - sectors_handled;
- r10_bio->mddev = mddev;
- r10_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
- r10_bio->state = 0;
- goto retry_write;
- }
- one_write_done(r10_bio);
- }
- static void 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;
- struct bio *split;
- if (unlikely(bio->bi_rw & REQ_FLUSH)) {
- md_flush_request(mddev, bio);
- return;
- }
- md_write_start(mddev, bio);
- do {
- /*
- * If this request crosses a chunk boundary, we need to split
- * it.
- */
- if (unlikely((bio->bi_iter.bi_sector & chunk_mask) +
- bio_sectors(bio) > chunk_sects
- && (conf->geo.near_copies < conf->geo.raid_disks
- || conf->prev.near_copies <
- conf->prev.raid_disks))) {
- split = bio_split(bio, chunk_sects -
- (bio->bi_iter.bi_sector &
- (chunk_sects - 1)),
- GFP_NOIO, fs_bio_set);
- bio_chain(split, bio);
- } else {
- split = bio;
- }
- __make_request(mddev, split);
- } while (split != bio);
- /* In case raid10d snuck in to freeze_array */
- wake_up(&conf->wait_barrier);
- }
- 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);
- for (i = 0; i < conf->geo.raid_disks; i++)
- seq_printf(seq, "%s",
- conf->mirrors[i].rdev &&
- test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
- seq_printf(seq, "]");
- }
- /* check if there are enough drives for
- * every block to appear on atleast one.
- * Don't consider the device numbered 'ignore'
- * as we might be about to remove it.
- */
- static int _enough(struct r10conf *conf, int previous, int ignore)
- {
- int first = 0;
- int has_enough = 0;
- int disks, ncopies;
- if (previous) {
- disks = conf->prev.raid_disks;
- ncopies = conf->prev.near_copies;
- } else {
- disks = conf->geo.raid_disks;
- ncopies = conf->geo.near_copies;
- }
- 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->flags, 0,
- BIT(MD_CHANGE_DEVS) | BIT(MD_CHANGE_PENDING));
- spin_unlock_irqrestore(&conf->device_lock, flags);
- printk(KERN_ALERT
- "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 raid10_info *tmp;
- printk(KERN_DEBUG "RAID10 conf printout:\n");
- if (!conf) {
- printk(KERN_DEBUG "(!conf)\n");
- return;
- }
- printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
- conf->geo.raid_disks);
- for (i = 0; i < conf->geo.raid_disks; i++) {
- char b[BDEVNAME_SIZE];
- tmp = conf->mirrors + i;
- if (tmp->rdev)
- printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
- i, !test_bit(In_sync, &tmp->rdev->flags),
- !test_bit(Faulty, &tmp->rdev->flags),
- bdevname(tmp->rdev->bdev,b));
- }
- }
- static void close_sync(struct r10conf *conf)
- {
- wait_barrier(conf);
- allow_barrier(conf);
- mempool_destroy(conf->r10buf_pool);
- conf->r10buf_pool = NULL;
- }
- 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 &&
- 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)))
- queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
- print_conf(conf);
- return err;
- }
- static int raid10_remove_disk(struct mddev *mddev, struct md_rdev