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linux/fs/btrfs/raid56.c
Qu Wenruo c186345a6b btrfs: make assert_rbio() to only check CONFIG_BTRFS_ASSERT 
According to the description, CONFIG_BTRFS_DEBUG is only for extra
debug info, meanwhile sanity checks should be managed by
CONFIG_BTRFS_ASSERT.

There is no need to check both to enable assert_rbio().

Just remove the check for CONFIG_BTRFS_DEBUG.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2012 Fusion-io All rights reserved.
* Copyright (C) 2012 Intel Corp. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/raid/pq.h>
#include <linux/hash.h>
#include <linux/list_sort.h>
#include <linux/raid/xor.h>
#include <linux/mm.h>
#include "messages.h"
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
#include "raid56.h"
#include "async-thread.h"
#include "file-item.h"
#include "btrfs_inode.h"
/* set when additional merges to this rbio are not allowed */
#define RBIO_RMW_LOCKED_BIT 1
/*
* set when this rbio is sitting in the hash, but it is just a cache
* of past RMW
*/
#define RBIO_CACHE_BIT 2
/*
* set when it is safe to trust the stripe_pages for caching
*/
#define RBIO_CACHE_READY_BIT 3
#define RBIO_CACHE_SIZE 1024
#define BTRFS_STRIPE_HASH_TABLE_BITS 11
static void dump_bioc(const struct btrfs_fs_info *fs_info, const struct btrfs_io_context *bioc)
{
if (unlikely(!bioc)) {
btrfs_crit(fs_info, "bioc=NULL");
return;
}
btrfs_crit(fs_info,
"bioc logical=%llu full_stripe=%llu size=%llu map_type=0x%llx mirror=%u replace_nr_stripes=%u replace_stripe_src=%d num_stripes=%u",
bioc->logical, bioc->full_stripe_logical, bioc->size,
bioc->map_type, bioc->mirror_num, bioc->replace_nr_stripes,
bioc->replace_stripe_src, bioc->num_stripes);
for (int i = 0; i < bioc->num_stripes; i++) {
btrfs_crit(fs_info, " nr=%d devid=%llu physical=%llu",
i, bioc->stripes[i].dev->devid,
bioc->stripes[i].physical);
}
}
static void btrfs_dump_rbio(const struct btrfs_fs_info *fs_info,
const struct btrfs_raid_bio *rbio)
{
if (!IS_ENABLED(CONFIG_BTRFS_ASSERT))
return;
dump_bioc(fs_info, rbio->bioc);
btrfs_crit(fs_info,
"rbio flags=0x%lx nr_sectors=%u nr_data=%u real_stripes=%u stripe_nsectors=%u scrubp=%u dbitmap=0x%lx",
rbio->flags, rbio->nr_sectors, rbio->nr_data,
rbio->real_stripes, rbio->stripe_nsectors,
rbio->scrubp, rbio->dbitmap);
}
#define ASSERT_RBIO(expr, rbio) \
({ \
if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \
const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \
(rbio)->bioc->fs_info : NULL; \
\
btrfs_dump_rbio(__fs_info, (rbio)); \
} \
ASSERT((expr)); \
})
#define ASSERT_RBIO_STRIPE(expr, rbio, stripe_nr) \
({ \
if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \
const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \
(rbio)->bioc->fs_info : NULL; \
\
btrfs_dump_rbio(__fs_info, (rbio)); \
btrfs_crit(__fs_info, "stripe_nr=%d", (stripe_nr)); \
} \
ASSERT((expr)); \
})
#define ASSERT_RBIO_SECTOR(expr, rbio, sector_nr) \
({ \
if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \
const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \
(rbio)->bioc->fs_info : NULL; \
\
btrfs_dump_rbio(__fs_info, (rbio)); \
btrfs_crit(__fs_info, "sector_nr=%d", (sector_nr)); \
} \
ASSERT((expr)); \
})
#define ASSERT_RBIO_LOGICAL(expr, rbio, logical) \
({ \
if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \
const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \
(rbio)->bioc->fs_info : NULL; \
\
btrfs_dump_rbio(__fs_info, (rbio)); \
btrfs_crit(__fs_info, "logical=%llu", (logical)); \
} \
ASSERT((expr)); \
})
/* Used by the raid56 code to lock stripes for read/modify/write */
struct btrfs_stripe_hash {
struct list_head hash_list;
spinlock_t lock;
};
/* Used by the raid56 code to lock stripes for read/modify/write */
struct btrfs_stripe_hash_table {
struct list_head stripe_cache;
spinlock_t cache_lock;
int cache_size;
struct btrfs_stripe_hash table[];
};
/*
* A bvec like structure to present a sector inside a page.
*
* Unlike bvec we don't need bvlen, as it's fixed to sectorsize.
*/
struct sector_ptr {
struct page *page;
unsigned int pgoff:24;
unsigned int uptodate:8;
};
static void rmw_rbio_work(struct work_struct *work);
static void rmw_rbio_work_locked(struct work_struct *work);
static void index_rbio_pages(struct btrfs_raid_bio *rbio);
static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
static int finish_parity_scrub(struct btrfs_raid_bio *rbio);
static void scrub_rbio_work_locked(struct work_struct *work);
static void free_raid_bio_pointers(struct btrfs_raid_bio *rbio)
{
bitmap_free(rbio->error_bitmap);
kfree(rbio->stripe_pages);
kfree(rbio->bio_sectors);
kfree(rbio->stripe_sectors);
kfree(rbio->finish_pointers);
}
static void free_raid_bio(struct btrfs_raid_bio *rbio)
{
int i;
if (!refcount_dec_and_test(&rbio->refs))
return;
WARN_ON(!list_empty(&rbio->stripe_cache));
WARN_ON(!list_empty(&rbio->hash_list));
WARN_ON(!bio_list_empty(&rbio->bio_list));
for (i = 0; i < rbio->nr_pages; i++) {
if (rbio->stripe_pages[i]) {
__free_page(rbio->stripe_pages[i]);
rbio->stripe_pages[i] = NULL;
}
}
btrfs_put_bioc(rbio->bioc);
free_raid_bio_pointers(rbio);
kfree(rbio);
}
static void start_async_work(struct btrfs_raid_bio *rbio, work_func_t work_func)
{
INIT_WORK(&rbio->work, work_func);
queue_work(rbio->bioc->fs_info->rmw_workers, &rbio->work);
}
/*
* the stripe hash table is used for locking, and to collect
* bios in hopes of making a full stripe
*/
int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
{
struct btrfs_stripe_hash_table *table;
struct btrfs_stripe_hash_table *x;
struct btrfs_stripe_hash *cur;
struct btrfs_stripe_hash *h;
int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
int i;
if (info->stripe_hash_table)
return 0;
/*
* The table is large, starting with order 4 and can go as high as
* order 7 in case lock debugging is turned on.
*
* Try harder to allocate and fallback to vmalloc to lower the chance
* of a failing mount.
*/
table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL);
if (!table)
return -ENOMEM;
spin_lock_init(&table->cache_lock);
INIT_LIST_HEAD(&table->stripe_cache);
h = table->table;
for (i = 0; i < num_entries; i++) {
cur = h + i;
INIT_LIST_HEAD(&cur->hash_list);
spin_lock_init(&cur->lock);
}
x = cmpxchg(&info->stripe_hash_table, NULL, table);
kvfree(x);
return 0;
}
/*
* caching an rbio means to copy anything from the
* bio_sectors array into the stripe_pages array. We
* use the page uptodate bit in the stripe cache array
* to indicate if it has valid data
*
* once the caching is done, we set the cache ready
* bit.
*/
static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
{
int i;
int ret;
ret = alloc_rbio_pages(rbio);
if (ret)
return;
for (i = 0; i < rbio->nr_sectors; i++) {
/* Some range not covered by bio (partial write), skip it */
if (!rbio->bio_sectors[i].page) {
/*
* Even if the sector is not covered by bio, if it is
* a data sector it should still be uptodate as it is
* read from disk.
*/
if (i < rbio->nr_data * rbio->stripe_nsectors)
ASSERT(rbio->stripe_sectors[i].uptodate);
continue;
}
ASSERT(rbio->stripe_sectors[i].page);
memcpy_page(rbio->stripe_sectors[i].page,
rbio->stripe_sectors[i].pgoff,
rbio->bio_sectors[i].page,
rbio->bio_sectors[i].pgoff,
rbio->bioc->fs_info->sectorsize);
rbio->stripe_sectors[i].uptodate = 1;
}
set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
}
/*
* we hash on the first logical address of the stripe
*/
static int rbio_bucket(struct btrfs_raid_bio *rbio)
{
u64 num = rbio->bioc->full_stripe_logical;
/*
* we shift down quite a bit. We're using byte
* addressing, and most of the lower bits are zeros.
* This tends to upset hash_64, and it consistently
* returns just one or two different values.
*
* shifting off the lower bits fixes things.
*/
return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
}
static bool full_page_sectors_uptodate(struct btrfs_raid_bio *rbio,
unsigned int page_nr)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
const u32 sectors_per_page = PAGE_SIZE / sectorsize;
int i;
ASSERT(page_nr < rbio->nr_pages);
for (i = sectors_per_page * page_nr;
i < sectors_per_page * page_nr + sectors_per_page;
i++) {
if (!rbio->stripe_sectors[i].uptodate)
return false;
}
return true;
}
/*
* Update the stripe_sectors[] array to use correct page and pgoff
*
* Should be called every time any page pointer in stripes_pages[] got modified.
*/
static void index_stripe_sectors(struct btrfs_raid_bio *rbio)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
u32 offset;
int i;
for (i = 0, offset = 0; i < rbio->nr_sectors; i++, offset += sectorsize) {
int page_index = offset >> PAGE_SHIFT;
ASSERT(page_index < rbio->nr_pages);
rbio->stripe_sectors[i].page = rbio->stripe_pages[page_index];
rbio->stripe_sectors[i].pgoff = offset_in_page(offset);
}
}
static void steal_rbio_page(struct btrfs_raid_bio *src,
struct btrfs_raid_bio *dest, int page_nr)
{
const u32 sectorsize = src->bioc->fs_info->sectorsize;
const u32 sectors_per_page = PAGE_SIZE / sectorsize;
int i;
if (dest->stripe_pages[page_nr])
__free_page(dest->stripe_pages[page_nr]);
dest->stripe_pages[page_nr] = src->stripe_pages[page_nr];
src->stripe_pages[page_nr] = NULL;
/* Also update the sector->uptodate bits. */
for (i = sectors_per_page * page_nr;
i < sectors_per_page * page_nr + sectors_per_page; i++)
dest->stripe_sectors[i].uptodate = true;
}
static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr)
{
const int sector_nr = (page_nr << PAGE_SHIFT) >>
rbio->bioc->fs_info->sectorsize_bits;
/*
* We have ensured PAGE_SIZE is aligned with sectorsize, thus
* we won't have a page which is half data half parity.
*
* Thus if the first sector of the page belongs to data stripes, then
* the full page belongs to data stripes.
*/
return (sector_nr < rbio->nr_data * rbio->stripe_nsectors);
}
/*
* Stealing an rbio means taking all the uptodate pages from the stripe array
* in the source rbio and putting them into the destination rbio.
*
* This will also update the involved stripe_sectors[] which are referring to
* the old pages.
*/
static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
{
int i;
if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
return;
for (i = 0; i < dest->nr_pages; i++) {
struct page *p = src->stripe_pages[i];
/*
* We don't need to steal P/Q pages as they will always be
* regenerated for RMW or full write anyway.
*/
if (!is_data_stripe_page(src, i))
continue;
/*
* If @src already has RBIO_CACHE_READY_BIT, it should have
* all data stripe pages present and uptodate.
*/
ASSERT(p);
ASSERT(full_page_sectors_uptodate(src, i));
steal_rbio_page(src, dest, i);
}
index_stripe_sectors(dest);
index_stripe_sectors(src);
}
/*
* merging means we take the bio_list from the victim and
* splice it into the destination. The victim should
* be discarded afterwards.
*
* must be called with dest->rbio_list_lock held
*/
static void merge_rbio(struct btrfs_raid_bio *dest,
struct btrfs_raid_bio *victim)
{
bio_list_merge_init(&dest->bio_list, &victim->bio_list);
dest->bio_list_bytes += victim->bio_list_bytes;
/* Also inherit the bitmaps from @victim. */
bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap,
dest->stripe_nsectors);
}
/*
* used to prune items that are in the cache. The caller
* must hold the hash table lock.
*/
static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
{
int bucket = rbio_bucket(rbio);
struct btrfs_stripe_hash_table *table;
struct btrfs_stripe_hash *h;
int freeit = 0;
/*
* check the bit again under the hash table lock.
*/
if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
return;
table = rbio->bioc->fs_info->stripe_hash_table;
h = table->table + bucket;
/* hold the lock for the bucket because we may be
* removing it from the hash table
*/
spin_lock(&h->lock);
/*
* hold the lock for the bio list because we need
* to make sure the bio list is empty
*/
spin_lock(&rbio->bio_list_lock);
if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
list_del_init(&rbio->stripe_cache);
table->cache_size -= 1;
freeit = 1;
/* if the bio list isn't empty, this rbio is
* still involved in an IO. We take it out
* of the cache list, and drop the ref that
* was held for the list.
*
* If the bio_list was empty, we also remove
* the rbio from the hash_table, and drop
* the corresponding ref
*/
if (bio_list_empty(&rbio->bio_list)) {
if (!list_empty(&rbio->hash_list)) {
list_del_init(&rbio->hash_list);
refcount_dec(&rbio->refs);
BUG_ON(!list_empty(&rbio->plug_list));
}
}
}
spin_unlock(&rbio->bio_list_lock);
spin_unlock(&h->lock);
if (freeit)
free_raid_bio(rbio);
}
/*
* prune a given rbio from the cache
*/
static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
{
struct btrfs_stripe_hash_table *table;
if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
return;
table = rbio->bioc->fs_info->stripe_hash_table;
spin_lock(&table->cache_lock);
__remove_rbio_from_cache(rbio);
spin_unlock(&table->cache_lock);
}
/*
* remove everything in the cache
*/
static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
{
struct btrfs_stripe_hash_table *table;
struct btrfs_raid_bio *rbio;
table = info->stripe_hash_table;
spin_lock(&table->cache_lock);
while (!list_empty(&table->stripe_cache)) {
rbio = list_entry(table->stripe_cache.next,
struct btrfs_raid_bio,
stripe_cache);
__remove_rbio_from_cache(rbio);
}
spin_unlock(&table->cache_lock);
}
/*
* remove all cached entries and free the hash table
* used by unmount
*/
void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
{
if (!info->stripe_hash_table)
return;
btrfs_clear_rbio_cache(info);
kvfree(info->stripe_hash_table);
info->stripe_hash_table = NULL;
}
/*
* insert an rbio into the stripe cache. It
* must have already been prepared by calling
* cache_rbio_pages
*
* If this rbio was already cached, it gets
* moved to the front of the lru.
*
* If the size of the rbio cache is too big, we
* prune an item.
*/
static void cache_rbio(struct btrfs_raid_bio *rbio)
{
struct btrfs_stripe_hash_table *table;
if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
return;
table = rbio->bioc->fs_info->stripe_hash_table;
spin_lock(&table->cache_lock);
spin_lock(&rbio->bio_list_lock);
/* bump our ref if we were not in the list before */
if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
refcount_inc(&rbio->refs);
if (!list_empty(&rbio->stripe_cache)){
list_move(&rbio->stripe_cache, &table->stripe_cache);
} else {
list_add(&rbio->stripe_cache, &table->stripe_cache);
table->cache_size += 1;
}
spin_unlock(&rbio->bio_list_lock);
if (table->cache_size > RBIO_CACHE_SIZE) {
struct btrfs_raid_bio *found;
found = list_entry(table->stripe_cache.prev,
struct btrfs_raid_bio,
stripe_cache);
if (found != rbio)
__remove_rbio_from_cache(found);
}
spin_unlock(&table->cache_lock);
}
/*
* helper function to run the xor_blocks api. It is only
* able to do MAX_XOR_BLOCKS at a time, so we need to
* loop through.
*/
static void run_xor(void **pages, int src_cnt, ssize_t len)
{
int src_off = 0;
int xor_src_cnt = 0;
void *dest = pages[src_cnt];
while(src_cnt > 0) {
xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
xor_blocks(xor_src_cnt, len, dest, pages + src_off);
src_cnt -= xor_src_cnt;
src_off += xor_src_cnt;
}
}
/*
* Returns true if the bio list inside this rbio covers an entire stripe (no
* rmw required).
*/
static int rbio_is_full(struct btrfs_raid_bio *rbio)
{
unsigned long size = rbio->bio_list_bytes;
int ret = 1;
spin_lock(&rbio->bio_list_lock);
if (size != rbio->nr_data * BTRFS_STRIPE_LEN)
ret = 0;
BUG_ON(size > rbio->nr_data * BTRFS_STRIPE_LEN);
spin_unlock(&rbio->bio_list_lock);
return ret;
}
/*
* returns 1 if it is safe to merge two rbios together.
* The merging is safe if the two rbios correspond to
* the same stripe and if they are both going in the same
* direction (read vs write), and if neither one is
* locked for final IO
*
* The caller is responsible for locking such that
* rmw_locked is safe to test
*/
static int rbio_can_merge(struct btrfs_raid_bio *last,
struct btrfs_raid_bio *cur)
{
if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
return 0;
/*
* we can't merge with cached rbios, since the
* idea is that when we merge the destination
* rbio is going to run our IO for us. We can
* steal from cached rbios though, other functions
* handle that.
*/
if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
test_bit(RBIO_CACHE_BIT, &cur->flags))
return 0;
if (last->bioc->full_stripe_logical != cur->bioc->full_stripe_logical)
return 0;
/* we can't merge with different operations */
if (last->operation != cur->operation)
return 0;
/*
* We've need read the full stripe from the drive.
* check and repair the parity and write the new results.
*
* We're not allowed to add any new bios to the
* bio list here, anyone else that wants to
* change this stripe needs to do their own rmw.
*/
if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
return 0;
if (last->operation == BTRFS_RBIO_READ_REBUILD)
return 0;
return 1;
}
static unsigned int rbio_stripe_sector_index(const struct btrfs_raid_bio *rbio,
unsigned int stripe_nr,
unsigned int sector_nr)
{
ASSERT_RBIO_STRIPE(stripe_nr < rbio->real_stripes, rbio, stripe_nr);
ASSERT_RBIO_SECTOR(sector_nr < rbio->stripe_nsectors, rbio, sector_nr);
return stripe_nr * rbio->stripe_nsectors + sector_nr;
}
/* Return a sector from rbio->stripe_sectors, not from the bio list */
static struct sector_ptr *rbio_stripe_sector(const struct btrfs_raid_bio *rbio,
unsigned int stripe_nr,
unsigned int sector_nr)
{
return &rbio->stripe_sectors[rbio_stripe_sector_index(rbio, stripe_nr,
sector_nr)];
}
/* Grab a sector inside P stripe */
static struct sector_ptr *rbio_pstripe_sector(const struct btrfs_raid_bio *rbio,
unsigned int sector_nr)
{
return rbio_stripe_sector(rbio, rbio->nr_data, sector_nr);
}
/* Grab a sector inside Q stripe, return NULL if not RAID6 */
static struct sector_ptr *rbio_qstripe_sector(const struct btrfs_raid_bio *rbio,
unsigned int sector_nr)
{
if (rbio->nr_data + 1 == rbio->real_stripes)
return NULL;
return rbio_stripe_sector(rbio, rbio->nr_data + 1, sector_nr);
}
/*
* The first stripe in the table for a logical address
* has the lock. rbios are added in one of three ways:
*
* 1) Nobody has the stripe locked yet. The rbio is given
* the lock and 0 is returned. The caller must start the IO
* themselves.
*
* 2) Someone has the stripe locked, but we're able to merge
* with the lock owner. The rbio is freed and the IO will
* start automatically along with the existing rbio. 1 is returned.
*
* 3) Someone has the stripe locked, but we're not able to merge.
* The rbio is added to the lock owner's plug list, or merged into
* an rbio already on the plug list. When the lock owner unlocks,
* the next rbio on the list is run and the IO is started automatically.
* 1 is returned
*
* If we return 0, the caller still owns the rbio and must continue with
* IO submission. If we return 1, the caller must assume the rbio has
* already been freed.
*/
static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
{
struct btrfs_stripe_hash *h;
struct btrfs_raid_bio *cur;
struct btrfs_raid_bio *pending;
struct btrfs_raid_bio *freeit = NULL;
struct btrfs_raid_bio *cache_drop = NULL;
int ret = 0;
h = rbio->bioc->fs_info->stripe_hash_table->table + rbio_bucket(rbio);
spin_lock(&h->lock);
list_for_each_entry(cur, &h->hash_list, hash_list) {
if (cur->bioc->full_stripe_logical != rbio->bioc->full_stripe_logical)
continue;
spin_lock(&cur->bio_list_lock);
/* Can we steal this cached rbio's pages? */
if (bio_list_empty(&cur->bio_list) &&
list_empty(&cur->plug_list) &&
test_bit(RBIO_CACHE_BIT, &cur->flags) &&
!test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) {
list_del_init(&cur->hash_list);
refcount_dec(&cur->refs);
steal_rbio(cur, rbio);
cache_drop = cur;
spin_unlock(&cur->bio_list_lock);
goto lockit;
}
/* Can we merge into the lock owner? */
if (rbio_can_merge(cur, rbio)) {
merge_rbio(cur, rbio);
spin_unlock(&cur->bio_list_lock);
freeit = rbio;
ret = 1;
goto out;
}
/*
* We couldn't merge with the running rbio, see if we can merge
* with the pending ones. We don't have to check for rmw_locked
* because there is no way they are inside finish_rmw right now
*/
list_for_each_entry(pending, &cur->plug_list, plug_list) {
if (rbio_can_merge(pending, rbio)) {
merge_rbio(pending, rbio);
spin_unlock(&cur->bio_list_lock);
freeit = rbio;
ret = 1;
goto out;
}
}
/*
* No merging, put us on the tail of the plug list, our rbio
* will be started with the currently running rbio unlocks
*/
list_add_tail(&rbio->plug_list, &cur->plug_list);
spin_unlock(&cur->bio_list_lock);
ret = 1;
goto out;
}
lockit:
refcount_inc(&rbio->refs);
list_add(&rbio->hash_list, &h->hash_list);
out:
spin_unlock(&h->lock);
if (cache_drop)
remove_rbio_from_cache(cache_drop);
if (freeit)
free_raid_bio(freeit);
return ret;
}
static void recover_rbio_work_locked(struct work_struct *work);
/*
* called as rmw or parity rebuild is completed. If the plug list has more
* rbios waiting for this stripe, the next one on the list will be started
*/
static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
{
int bucket;
struct btrfs_stripe_hash *h;
int keep_cache = 0;
bucket = rbio_bucket(rbio);
h = rbio->bioc->fs_info->stripe_hash_table->table + bucket;
if (list_empty(&rbio->plug_list))
cache_rbio(rbio);
spin_lock(&h->lock);
spin_lock(&rbio->bio_list_lock);
if (!list_empty(&rbio->hash_list)) {
/*
* if we're still cached and there is no other IO
* to perform, just leave this rbio here for others
* to steal from later
*/
if (list_empty(&rbio->plug_list) &&
test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
keep_cache = 1;
clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
BUG_ON(!bio_list_empty(&rbio->bio_list));
goto done;
}
list_del_init(&rbio->hash_list);
refcount_dec(&rbio->refs);
/*
* we use the plug list to hold all the rbios
* waiting for the chance to lock this stripe.
* hand the lock over to one of them.
*/
if (!list_empty(&rbio->plug_list)) {
struct btrfs_raid_bio *next;
struct list_head *head = rbio->plug_list.next;
next = list_entry(head, struct btrfs_raid_bio,
plug_list);
list_del_init(&rbio->plug_list);
list_add(&next->hash_list, &h->hash_list);
refcount_inc(&next->refs);
spin_unlock(&rbio->bio_list_lock);
spin_unlock(&h->lock);
if (next->operation == BTRFS_RBIO_READ_REBUILD) {
start_async_work(next, recover_rbio_work_locked);
} else if (next->operation == BTRFS_RBIO_WRITE) {
steal_rbio(rbio, next);
start_async_work(next, rmw_rbio_work_locked);
} else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
steal_rbio(rbio, next);
start_async_work(next, scrub_rbio_work_locked);
}
goto done_nolock;
}
}
done:
spin_unlock(&rbio->bio_list_lock);
spin_unlock(&h->lock);
done_nolock:
if (!keep_cache)
remove_rbio_from_cache(rbio);
}
static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
{
struct bio *next;
while (cur) {
next = cur->bi_next;
cur->bi_next = NULL;
cur->bi_status = err;
bio_endio(cur);
cur = next;
}
}
/*
* this frees the rbio and runs through all the bios in the
* bio_list and calls end_io on them
*/
static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err)
{
struct bio *cur = bio_list_get(&rbio->bio_list);
struct bio *extra;
kfree(rbio->csum_buf);
bitmap_free(rbio->csum_bitmap);
rbio->csum_buf = NULL;
rbio->csum_bitmap = NULL;
/*
* Clear the data bitmap, as the rbio may be cached for later usage.
* do this before before unlock_stripe() so there will be no new bio
* for this bio.
*/
bitmap_clear(&rbio->dbitmap, 0, rbio->stripe_nsectors);
/*
* At this moment, rbio->bio_list is empty, however since rbio does not
* always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the
* hash list, rbio may be merged with others so that rbio->bio_list
* becomes non-empty.
* Once unlock_stripe() is done, rbio->bio_list will not be updated any
* more and we can call bio_endio() on all queued bios.
*/
unlock_stripe(rbio);
extra = bio_list_get(&rbio->bio_list);
free_raid_bio(rbio);
rbio_endio_bio_list(cur, err);
if (extra)
rbio_endio_bio_list(extra, err);
}
/*
* Get a sector pointer specified by its @stripe_nr and @sector_nr.
*
* @rbio: The raid bio
* @stripe_nr: Stripe number, valid range [0, real_stripe)
* @sector_nr: Sector number inside the stripe,
* valid range [0, stripe_nsectors)
* @bio_list_only: Whether to use sectors inside the bio list only.
*
* The read/modify/write code wants to reuse the original bio page as much
* as possible, and only use stripe_sectors as fallback.
*/
static struct sector_ptr *sector_in_rbio(struct btrfs_raid_bio *rbio,
int stripe_nr, int sector_nr,
bool bio_list_only)
{
struct sector_ptr *sector;
int index;
ASSERT_RBIO_STRIPE(stripe_nr >= 0 && stripe_nr < rbio->real_stripes,
rbio, stripe_nr);
ASSERT_RBIO_SECTOR(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors,
rbio, sector_nr);
index = stripe_nr * rbio->stripe_nsectors + sector_nr;
ASSERT(index >= 0 && index < rbio->nr_sectors);
spin_lock(&rbio->bio_list_lock);
sector = &rbio->bio_sectors[index];
if (sector->page || bio_list_only) {
/* Don't return sector without a valid page pointer */
if (!sector->page)
sector = NULL;
spin_unlock(&rbio->bio_list_lock);
return sector;
}
spin_unlock(&rbio->bio_list_lock);
return &rbio->stripe_sectors[index];
}
/*
* allocation and initial setup for the btrfs_raid_bio. Not
* this does not allocate any pages for rbio->pages.
*/
static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
struct btrfs_io_context *bioc)
{
const unsigned int real_stripes = bioc->num_stripes - bioc->replace_nr_stripes;
const unsigned int stripe_npages = BTRFS_STRIPE_LEN >> PAGE_SHIFT;
const unsigned int num_pages = stripe_npages * real_stripes;
const unsigned int stripe_nsectors =
BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
const unsigned int num_sectors = stripe_nsectors * real_stripes;
struct btrfs_raid_bio *rbio;
/* PAGE_SIZE must also be aligned to sectorsize for subpage support */
ASSERT(IS_ALIGNED(PAGE_SIZE, fs_info->sectorsize));
/*
* Our current stripe len should be fixed to 64k thus stripe_nsectors
* (at most 16) should be no larger than BITS_PER_LONG.
*/
ASSERT(stripe_nsectors <= BITS_PER_LONG);
/*
* Real stripes must be between 2 (2 disks RAID5, aka RAID1) and 256
* (limited by u8).
*/
ASSERT(real_stripes >= 2);
ASSERT(real_stripes <= U8_MAX);
rbio = kzalloc(sizeof(*rbio), GFP_NOFS);
if (!rbio)
return ERR_PTR(-ENOMEM);
rbio->stripe_pages = kcalloc(num_pages, sizeof(struct page *),
GFP_NOFS);
rbio->bio_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
GFP_NOFS);
rbio->stripe_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr),
GFP_NOFS);
rbio->finish_pointers = kcalloc(real_stripes, sizeof(void *), GFP_NOFS);
rbio->error_bitmap = bitmap_zalloc(num_sectors, GFP_NOFS);
if (!rbio->stripe_pages || !rbio->bio_sectors || !rbio->stripe_sectors ||
!rbio->finish_pointers || !rbio->error_bitmap) {
free_raid_bio_pointers(rbio);
kfree(rbio);
return ERR_PTR(-ENOMEM);
}
bio_list_init(&rbio->bio_list);
init_waitqueue_head(&rbio->io_wait);
INIT_LIST_HEAD(&rbio->plug_list);
spin_lock_init(&rbio->bio_list_lock);
INIT_LIST_HEAD(&rbio->stripe_cache);
INIT_LIST_HEAD(&rbio->hash_list);
btrfs_get_bioc(bioc);
rbio->bioc = bioc;
rbio->nr_pages = num_pages;
rbio->nr_sectors = num_sectors;
rbio->real_stripes = real_stripes;
rbio->stripe_npages = stripe_npages;
rbio->stripe_nsectors = stripe_nsectors;
refcount_set(&rbio->refs, 1);
atomic_set(&rbio->stripes_pending, 0);
ASSERT(btrfs_nr_parity_stripes(bioc->map_type));
rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type);
ASSERT(rbio->nr_data > 0);
return rbio;
}
/* allocate pages for all the stripes in the bio, including parity */
static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
{
int ret;
ret = btrfs_alloc_page_array(rbio->nr_pages, rbio->stripe_pages, false);
if (ret < 0)
return ret;
/* Mapping all sectors */
index_stripe_sectors(rbio);
return 0;
}
/* only allocate pages for p/q stripes */
static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
{
const int data_pages = rbio->nr_data * rbio->stripe_npages;
int ret;
ret = btrfs_alloc_page_array(rbio->nr_pages - data_pages,
rbio->stripe_pages + data_pages, false);
if (ret < 0)
return ret;
index_stripe_sectors(rbio);
return 0;
}
/*
* Return the total number of errors found in the vertical stripe of @sector_nr.
*
* @faila and @failb will also be updated to the first and second stripe
* number of the errors.
*/
static int get_rbio_veritical_errors(struct btrfs_raid_bio *rbio, int sector_nr,
int *faila, int *failb)
{
int stripe_nr;
int found_errors = 0;
if (faila || failb) {
/*
* Both @faila and @failb should be valid pointers if any of
* them is specified.
*/
ASSERT(faila && failb);
*faila = -1;
*failb = -1;
}
for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
int total_sector_nr = stripe_nr * rbio->stripe_nsectors + sector_nr;
if (test_bit(total_sector_nr, rbio->error_bitmap)) {
found_errors++;
if (faila) {
/* Update faila and failb. */
if (*faila < 0)
*faila = stripe_nr;
else if (*failb < 0)
*failb = stripe_nr;
}
}
}
return found_errors;
}
/*
* Add a single sector @sector into our list of bios for IO.
*
* Return 0 if everything went well.
* Return <0 for error.
*/
static int rbio_add_io_sector(struct btrfs_raid_bio *rbio,
struct bio_list *bio_list,
struct sector_ptr *sector,
unsigned int stripe_nr,
unsigned int sector_nr,
enum req_op op)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
struct bio *last = bio_list->tail;
int ret;
struct bio *bio;
struct btrfs_io_stripe *stripe;
u64 disk_start;
/*
* Note: here stripe_nr has taken device replace into consideration,
* thus it can be larger than rbio->real_stripe.
* So here we check against bioc->num_stripes, not rbio->real_stripes.
*/
ASSERT_RBIO_STRIPE(stripe_nr >= 0 && stripe_nr < rbio->bioc->num_stripes,
rbio, stripe_nr);
ASSERT_RBIO_SECTOR(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors,
rbio, sector_nr);
ASSERT(sector->page);
stripe = &rbio->bioc->stripes[stripe_nr];
disk_start = stripe->physical + sector_nr * sectorsize;
/* if the device is missing, just fail this stripe */
if (!stripe->dev->bdev) {
int found_errors;
set_bit(stripe_nr * rbio->stripe_nsectors + sector_nr,
rbio->error_bitmap);
/* Check if we have reached tolerance early. */
found_errors = get_rbio_veritical_errors(rbio, sector_nr,
NULL, NULL);
if (found_errors > rbio->bioc->max_errors)
return -EIO;
return 0;
}
/* see if we can add this page onto our existing bio */
if (last) {
u64 last_end = last->bi_iter.bi_sector << SECTOR_SHIFT;
last_end += last->bi_iter.bi_size;
/*
* we can't merge these if they are from different
* devices or if they are not contiguous
*/
if (last_end == disk_start && !last->bi_status &&
last->bi_bdev == stripe->dev->bdev) {
ret = bio_add_page(last, sector->page, sectorsize,
sector->pgoff);
if (ret == sectorsize)
return 0;
}
}
/* put a new bio on the list */
bio = bio_alloc(stripe->dev->bdev,
max(BTRFS_STRIPE_LEN >> PAGE_SHIFT, 1),
op, GFP_NOFS);
bio->bi_iter.bi_sector = disk_start >> SECTOR_SHIFT;
bio->bi_private = rbio;
__bio_add_page(bio, sector->page, sectorsize, sector->pgoff);
bio_list_add(bio_list, bio);
return 0;
}
static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
struct bio_vec bvec;
struct bvec_iter iter;
u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
rbio->bioc->full_stripe_logical;
bio_for_each_segment(bvec, bio, iter) {
u32 bvec_offset;
for (bvec_offset = 0; bvec_offset < bvec.bv_len;
bvec_offset += sectorsize, offset += sectorsize) {
int index = offset / sectorsize;
struct sector_ptr *sector = &rbio->bio_sectors[index];
sector->page = bvec.bv_page;
sector->pgoff = bvec.bv_offset + bvec_offset;
ASSERT(sector->pgoff < PAGE_SIZE);
}
}
}
/*
* helper function to walk our bio list and populate the bio_pages array with
* the result. This seems expensive, but it is faster than constantly
* searching through the bio list as we setup the IO in finish_rmw or stripe
* reconstruction.
*
* This must be called before you trust the answers from page_in_rbio
*/
static void index_rbio_pages(struct btrfs_raid_bio *rbio)
{
struct bio *bio;
spin_lock(&rbio->bio_list_lock);
bio_list_for_each(bio, &rbio->bio_list)
index_one_bio(rbio, bio);
spin_unlock(&rbio->bio_list_lock);
}
static void bio_get_trace_info(struct btrfs_raid_bio *rbio, struct bio *bio,
struct raid56_bio_trace_info *trace_info)
{
const struct btrfs_io_context *bioc = rbio->bioc;
int i;
ASSERT(bioc);
/* We rely on bio->bi_bdev to find the stripe number. */
if (!bio->bi_bdev)
goto not_found;
for (i = 0; i < bioc->num_stripes; i++) {
if (bio->bi_bdev != bioc->stripes[i].dev->bdev)
continue;
trace_info->stripe_nr = i;
trace_info->devid = bioc->stripes[i].dev->devid;
trace_info->offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
bioc->stripes[i].physical;
return;
}
not_found:
trace_info->devid = -1;
trace_info->offset = -1;
trace_info->stripe_nr = -1;
}
static inline void bio_list_put(struct bio_list *bio_list)
{
struct bio *bio;
while ((bio = bio_list_pop(bio_list)))
bio_put(bio);
}
static void assert_rbio(struct btrfs_raid_bio *rbio)
{
if (!IS_ENABLED(CONFIG_BTRFS_ASSERT))
return;
/*
* At least two stripes (2 disks RAID5), and since real_stripes is U8,
* we won't go beyond 256 disks anyway.
*/
ASSERT_RBIO(rbio->real_stripes >= 2, rbio);
ASSERT_RBIO(rbio->nr_data > 0, rbio);
/*
* This is another check to make sure nr data stripes is smaller
* than total stripes.
*/
ASSERT_RBIO(rbio->nr_data < rbio->real_stripes, rbio);
}
/* Generate PQ for one vertical stripe. */
static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr)
{
void **pointers = rbio->finish_pointers;
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
struct sector_ptr *sector;
int stripe;
const bool has_qstripe = rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6;
/* First collect one sector from each data stripe */
for (stripe = 0; stripe < rbio->nr_data; stripe++) {
sector = sector_in_rbio(rbio, stripe, sectornr, 0);
pointers[stripe] = kmap_local_page(sector->page) +
sector->pgoff;
}
/* Then add the parity stripe */
sector = rbio_pstripe_sector(rbio, sectornr);
sector->uptodate = 1;
pointers[stripe++] = kmap_local_page(sector->page) + sector->pgoff;
if (has_qstripe) {
/*
* RAID6, add the qstripe and call the library function
* to fill in our p/q
*/
sector = rbio_qstripe_sector(rbio, sectornr);
sector->uptodate = 1;
pointers[stripe++] = kmap_local_page(sector->page) +
sector->pgoff;
assert_rbio(rbio);
raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
pointers);
} else {
/* raid5 */
memcpy(pointers[rbio->nr_data], pointers[0], sectorsize);
run_xor(pointers + 1, rbio->nr_data - 1, sectorsize);
}
for (stripe = stripe - 1; stripe >= 0; stripe--)
kunmap_local(pointers[stripe]);
}
static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio,
struct bio_list *bio_list)
{
/* The total sector number inside the full stripe. */
int total_sector_nr;
int sectornr;
int stripe;
int ret;
ASSERT(bio_list_size(bio_list) == 0);
/* We should have at least one data sector. */
ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));
/*
* Reset errors, as we may have errors inherited from from degraded
* write.
*/
bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
/*
* Start assembly. Make bios for everything from the higher layers (the
* bio_list in our rbio) and our P/Q. Ignore everything else.
*/
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
struct sector_ptr *sector;
stripe = total_sector_nr / rbio->stripe_nsectors;
sectornr = total_sector_nr % rbio->stripe_nsectors;
/* This vertical stripe has no data, skip it. */
if (!test_bit(sectornr, &rbio->dbitmap))
continue;
if (stripe < rbio->nr_data) {
sector = sector_in_rbio(rbio, stripe, sectornr, 1);
if (!sector)
continue;
} else {
sector = rbio_stripe_sector(rbio, stripe, sectornr);
}
ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
sectornr, REQ_OP_WRITE);
if (ret)
goto error;
}
if (likely(!rbio->bioc->replace_nr_stripes))
return 0;
/*
* Make a copy for the replace target device.
*
* Thus the source stripe number (in replace_stripe_src) should be valid.
*/
ASSERT(rbio->bioc->replace_stripe_src >= 0);
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
struct sector_ptr *sector;
stripe = total_sector_nr / rbio->stripe_nsectors;
sectornr = total_sector_nr % rbio->stripe_nsectors;
/*
* For RAID56, there is only one device that can be replaced,
* and replace_stripe_src[0] indicates the stripe number we
* need to copy from.
*/
if (stripe != rbio->bioc->replace_stripe_src) {
/*
* We can skip the whole stripe completely, note
* total_sector_nr will be increased by one anyway.
*/
ASSERT(sectornr == 0);
total_sector_nr += rbio->stripe_nsectors - 1;
continue;
}
/* This vertical stripe has no data, skip it. */
if (!test_bit(sectornr, &rbio->dbitmap))
continue;
if (stripe < rbio->nr_data) {
sector = sector_in_rbio(rbio, stripe, sectornr, 1);
if (!sector)
continue;
} else {
sector = rbio_stripe_sector(rbio, stripe, sectornr);
}
ret = rbio_add_io_sector(rbio, bio_list, sector,
rbio->real_stripes,
sectornr, REQ_OP_WRITE);
if (ret)
goto error;
}
return 0;
error:
bio_list_put(bio_list);
return -EIO;
}
static void set_rbio_range_error(struct btrfs_raid_bio *rbio, struct bio *bio)
{
struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -
rbio->bioc->full_stripe_logical;
int total_nr_sector = offset >> fs_info->sectorsize_bits;
ASSERT(total_nr_sector < rbio->nr_data * rbio->stripe_nsectors);
bitmap_set(rbio->error_bitmap, total_nr_sector,
bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
/*
* Special handling for raid56_alloc_missing_rbio() used by
* scrub/replace. Unlike call path in raid56_parity_recover(), they
* pass an empty bio here. Thus we have to find out the missing device
* and mark the stripe error instead.
*/
if (bio->bi_iter.bi_size == 0) {
bool found_missing = false;
int stripe_nr;
for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
if (!rbio->bioc->stripes[stripe_nr].dev->bdev) {
found_missing = true;
bitmap_set(rbio->error_bitmap,
stripe_nr * rbio->stripe_nsectors,
rbio->stripe_nsectors);
}
}
ASSERT(found_missing);
}
}
/*
* For subpage case, we can no longer set page Up-to-date directly for
* stripe_pages[], thus we need to locate the sector.
*/
static struct sector_ptr *find_stripe_sector(struct btrfs_raid_bio *rbio,
struct page *page,
unsigned int pgoff)
{
int i;
for (i = 0; i < rbio->nr_sectors; i++) {
struct sector_ptr *sector = &rbio->stripe_sectors[i];
if (sector->page == page && sector->pgoff == pgoff)
return sector;
}
return NULL;
}
/*
* this sets each page in the bio uptodate. It should only be used on private
* rbio pages, nothing that comes in from the higher layers
*/
static void set_bio_pages_uptodate(struct btrfs_raid_bio *rbio, struct bio *bio)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
struct bio_vec *bvec;
struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
bio_for_each_segment_all(bvec, bio, iter_all) {
struct sector_ptr *sector;
int pgoff;
for (pgoff = bvec->bv_offset; pgoff - bvec->bv_offset < bvec->bv_len;
pgoff += sectorsize) {
sector = find_stripe_sector(rbio, bvec->bv_page, pgoff);
ASSERT(sector);
if (sector)
sector->uptodate = 1;
}
}
}
static int get_bio_sector_nr(struct btrfs_raid_bio *rbio, struct bio *bio)
{
struct bio_vec *bv = bio_first_bvec_all(bio);
int i;
for (i = 0; i < rbio->nr_sectors; i++) {
struct sector_ptr *sector;
sector = &rbio->stripe_sectors[i];
if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
break;
sector = &rbio->bio_sectors[i];
if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset)
break;
}
ASSERT(i < rbio->nr_sectors);
return i;
}
static void rbio_update_error_bitmap(struct btrfs_raid_bio *rbio, struct bio *bio)
{
int total_sector_nr = get_bio_sector_nr(rbio, bio);
u32 bio_size = 0;
struct bio_vec *bvec;
int i;
bio_for_each_bvec_all(bvec, bio, i)
bio_size += bvec->bv_len;
/*
* Since we can have multiple bios touching the error_bitmap, we cannot
* call bitmap_set() without protection.
*
* Instead use set_bit() for each bit, as set_bit() itself is atomic.
*/
for (i = total_sector_nr; i < total_sector_nr +
(bio_size >> rbio->bioc->fs_info->sectorsize_bits); i++)
set_bit(i, rbio->error_bitmap);
}
/* Verify the data sectors at read time. */
static void verify_bio_data_sectors(struct btrfs_raid_bio *rbio,
struct bio *bio)
{
struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
int total_sector_nr = get_bio_sector_nr(rbio, bio);
struct bio_vec *bvec;
struct bvec_iter_all iter_all;
/* No data csum for the whole stripe, no need to verify. */
if (!rbio->csum_bitmap || !rbio->csum_buf)
return;
/* P/Q stripes, they have no data csum to verify against. */
if (total_sector_nr >= rbio->nr_data * rbio->stripe_nsectors)
return;
bio_for_each_segment_all(bvec, bio, iter_all) {
int bv_offset;
for (bv_offset = bvec->bv_offset;
bv_offset < bvec->bv_offset + bvec->bv_len;
bv_offset += fs_info->sectorsize, total_sector_nr++) {
u8 csum_buf[BTRFS_CSUM_SIZE];
u8 *expected_csum = rbio->csum_buf +
total_sector_nr * fs_info->csum_size;
int ret;
/* No csum for this sector, skip to the next sector. */
if (!test_bit(total_sector_nr, rbio->csum_bitmap))
continue;
ret = btrfs_check_sector_csum(fs_info, bvec->bv_page,
bv_offset, csum_buf, expected_csum);
if (ret < 0)
set_bit(total_sector_nr, rbio->error_bitmap);
}
}
}
static void raid_wait_read_end_io(struct bio *bio)
{
struct btrfs_raid_bio *rbio = bio->bi_private;
if (bio->bi_status) {
rbio_update_error_bitmap(rbio, bio);
} else {
set_bio_pages_uptodate(rbio, bio);
verify_bio_data_sectors(rbio, bio);
}
bio_put(bio);
if (atomic_dec_and_test(&rbio->stripes_pending))
wake_up(&rbio->io_wait);
}
static void submit_read_wait_bio_list(struct btrfs_raid_bio *rbio,
struct bio_list *bio_list)
{
struct bio *bio;
atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
while ((bio = bio_list_pop(bio_list))) {
bio->bi_end_io = raid_wait_read_end_io;
if (trace_raid56_read_enabled()) {
struct raid56_bio_trace_info trace_info = { 0 };
bio_get_trace_info(rbio, bio, &trace_info);
trace_raid56_read(rbio, bio, &trace_info);
}
submit_bio(bio);
}
wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
}
static int alloc_rbio_data_pages(struct btrfs_raid_bio *rbio)
{
const int data_pages = rbio->nr_data * rbio->stripe_npages;
int ret;
ret = btrfs_alloc_page_array(data_pages, rbio->stripe_pages, false);
if (ret < 0)
return ret;
index_stripe_sectors(rbio);
return 0;
}
/*
* We use plugging call backs to collect full stripes.
* Any time we get a partial stripe write while plugged
* we collect it into a list. When the unplug comes down,
* we sort the list by logical block number and merge
* everything we can into the same rbios
*/
struct btrfs_plug_cb {
struct blk_plug_cb cb;
struct btrfs_fs_info *info;
struct list_head rbio_list;
};
/*
* rbios on the plug list are sorted for easier merging.
*/
static int plug_cmp(void *priv, const struct list_head *a,
const struct list_head *b)
{
const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
plug_list);
const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
plug_list);
u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
if (a_sector < b_sector)
return -1;
if (a_sector > b_sector)
return 1;
return 0;
}
static void raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
struct btrfs_plug_cb *plug = container_of(cb, struct btrfs_plug_cb, cb);
struct btrfs_raid_bio *cur;
struct btrfs_raid_bio *last = NULL;
list_sort(NULL, &plug->rbio_list, plug_cmp);
while (!list_empty(&plug->rbio_list)) {
cur = list_entry(plug->rbio_list.next,
struct btrfs_raid_bio, plug_list);
list_del_init(&cur->plug_list);
if (rbio_is_full(cur)) {
/* We have a full stripe, queue it down. */
start_async_work(cur, rmw_rbio_work);
continue;
}
if (last) {
if (rbio_can_merge(last, cur)) {
merge_rbio(last, cur);
free_raid_bio(cur);
continue;
}
start_async_work(last, rmw_rbio_work);
}
last = cur;
}
if (last)
start_async_work(last, rmw_rbio_work);
kfree(plug);
}
/* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */
static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio)
{
const struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT;
const u64 full_stripe_start = rbio->bioc->full_stripe_logical;
const u32 orig_len = orig_bio->bi_iter.bi_size;
const u32 sectorsize = fs_info->sectorsize;
u64 cur_logical;
ASSERT_RBIO_LOGICAL(orig_logical >= full_stripe_start &&
orig_logical + orig_len <= full_stripe_start +
rbio->nr_data * BTRFS_STRIPE_LEN,
rbio, orig_logical);
bio_list_add(&rbio->bio_list, orig_bio);
rbio->bio_list_bytes += orig_bio->bi_iter.bi_size;
/* Update the dbitmap. */
for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len;
cur_logical += sectorsize) {
int bit = ((u32)(cur_logical - full_stripe_start) >>
fs_info->sectorsize_bits) % rbio->stripe_nsectors;
set_bit(bit, &rbio->dbitmap);
}
}
/*
* our main entry point for writes from the rest of the FS.
*/
void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
{
struct btrfs_fs_info *fs_info = bioc->fs_info;
struct btrfs_raid_bio *rbio;
struct btrfs_plug_cb *plug = NULL;
struct blk_plug_cb *cb;
rbio = alloc_rbio(fs_info, bioc);
if (IS_ERR(rbio)) {
bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
bio_endio(bio);
return;
}
rbio->operation = BTRFS_RBIO_WRITE;
rbio_add_bio(rbio, bio);
/*
* Don't plug on full rbios, just get them out the door
* as quickly as we can
*/
if (!rbio_is_full(rbio)) {
cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
if (cb) {
plug = container_of(cb, struct btrfs_plug_cb, cb);
if (!plug->info) {
plug->info = fs_info;
INIT_LIST_HEAD(&plug->rbio_list);
}
list_add_tail(&rbio->plug_list, &plug->rbio_list);
return;
}
}
/*
* Either we don't have any existing plug, or we're doing a full stripe,
* queue the rmw work now.
*/
start_async_work(rbio, rmw_rbio_work);
}
static int verify_one_sector(struct btrfs_raid_bio *rbio,
int stripe_nr, int sector_nr)
{
struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
struct sector_ptr *sector;
u8 csum_buf[BTRFS_CSUM_SIZE];
u8 *csum_expected;
int ret;
if (!rbio->csum_bitmap || !rbio->csum_buf)
return 0;
/* No way to verify P/Q as they are not covered by data csum. */
if (stripe_nr >= rbio->nr_data)
return 0;
/*
* If we're rebuilding a read, we have to use pages from the
* bio list if possible.
*/
if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
} else {
sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
}
ASSERT(sector->page);
csum_expected = rbio->csum_buf +
(stripe_nr * rbio->stripe_nsectors + sector_nr) *
fs_info->csum_size;
ret = btrfs_check_sector_csum(fs_info, sector->page, sector->pgoff,
csum_buf, csum_expected);
return ret;
}
/*
* Recover a vertical stripe specified by @sector_nr.
* @*pointers are the pre-allocated pointers by the caller, so we don't
* need to allocate/free the pointers again and again.
*/
static int recover_vertical(struct btrfs_raid_bio *rbio, int sector_nr,
void **pointers, void **unmap_array)
{
struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
struct sector_ptr *sector;
const u32 sectorsize = fs_info->sectorsize;
int found_errors;
int faila;
int failb;
int stripe_nr;
int ret = 0;
/*
* Now we just use bitmap to mark the horizontal stripes in
* which we have data when doing parity scrub.
*/
if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
!test_bit(sector_nr, &rbio->dbitmap))
return 0;
found_errors = get_rbio_veritical_errors(rbio, sector_nr, &faila,
&failb);
/*
* No errors in the vertical stripe, skip it. Can happen for recovery
* which only part of a stripe failed csum check.
*/
if (!found_errors)
return 0;
if (found_errors > rbio->bioc->max_errors)
return -EIO;
/*
* Setup our array of pointers with sectors from each stripe
*
* NOTE: store a duplicate array of pointers to preserve the
* pointer order.
*/
for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) {
/*
* If we're rebuilding a read, we have to use pages from the
* bio list if possible.
*/
if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0);
} else {
sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr);
}
ASSERT(sector->page);
pointers[stripe_nr] = kmap_local_page(sector->page) +
sector->pgoff;
unmap_array[stripe_nr] = pointers[stripe_nr];
}
/* All raid6 handling here */
if (rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6) {
/* Single failure, rebuild from parity raid5 style */
if (failb < 0) {
if (faila == rbio->nr_data)
/*
* Just the P stripe has failed, without
* a bad data or Q stripe.
* We have nothing to do, just skip the
* recovery for this stripe.
*/
goto cleanup;
/*
* a single failure in raid6 is rebuilt
* in the pstripe code below
*/
goto pstripe;
}
/*
* If the q stripe is failed, do a pstripe reconstruction from
* the xors.
* If both the q stripe and the P stripe are failed, we're
* here due to a crc mismatch and we can't give them the
* data they want.
*/
if (failb == rbio->real_stripes - 1) {
if (faila == rbio->real_stripes - 2)
/*
* Only P and Q are corrupted.
* We only care about data stripes recovery,
* can skip this vertical stripe.
*/
goto cleanup;
/*
* Otherwise we have one bad data stripe and
* a good P stripe. raid5!
*/
goto pstripe;
}
if (failb == rbio->real_stripes - 2) {
raid6_datap_recov(rbio->real_stripes, sectorsize,
faila, pointers);
} else {
raid6_2data_recov(rbio->real_stripes, sectorsize,
faila, failb, pointers);
}
} else {
void *p;
/* Rebuild from P stripe here (raid5 or raid6). */
ASSERT(failb == -1);
pstripe:
/* Copy parity block into failed block to start with */
memcpy(pointers[faila], pointers[rbio->nr_data], sectorsize);
/* Rearrange the pointer array */
p = pointers[faila];
for (stripe_nr = faila; stripe_nr < rbio->nr_data - 1;
stripe_nr++)
pointers[stripe_nr] = pointers[stripe_nr + 1];
pointers[rbio->nr_data - 1] = p;
/* Xor in the rest */
run_xor(pointers, rbio->nr_data - 1, sectorsize);
}
/*
* No matter if this is a RMW or recovery, we should have all
* failed sectors repaired in the vertical stripe, thus they are now
* uptodate.
* Especially if we determine to cache the rbio, we need to
* have at least all data sectors uptodate.
*
* If possible, also check if the repaired sector matches its data
* checksum.
*/
if (faila >= 0) {
ret = verify_one_sector(rbio, faila, sector_nr);
if (ret < 0)
goto cleanup;
sector = rbio_stripe_sector(rbio, faila, sector_nr);
sector->uptodate = 1;
}
if (failb >= 0) {
ret = verify_one_sector(rbio, failb, sector_nr);
if (ret < 0)
goto cleanup;
sector = rbio_stripe_sector(rbio, failb, sector_nr);
sector->uptodate = 1;
}
cleanup:
for (stripe_nr = rbio->real_stripes - 1; stripe_nr >= 0; stripe_nr--)
kunmap_local(unmap_array[stripe_nr]);
return ret;
}
static int recover_sectors(struct btrfs_raid_bio *rbio)
{
void **pointers = NULL;
void **unmap_array = NULL;
int sectornr;
int ret = 0;
/*
* @pointers array stores the pointer for each sector.
*
* @unmap_array stores copy of pointers that does not get reordered
* during reconstruction so that kunmap_local works.
*/
pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
if (!pointers || !unmap_array) {
ret = -ENOMEM;
goto out;
}
if (rbio->operation == BTRFS_RBIO_READ_REBUILD) {
spin_lock(&rbio->bio_list_lock);
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
spin_unlock(&rbio->bio_list_lock);
}
index_rbio_pages(rbio);
for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
ret = recover_vertical(rbio, sectornr, pointers, unmap_array);
if (ret < 0)
break;
}
out:
kfree(pointers);
kfree(unmap_array);
return ret;
}
static void recover_rbio(struct btrfs_raid_bio *rbio)
{
struct bio_list bio_list = BIO_EMPTY_LIST;
int total_sector_nr;
int ret = 0;
/*
* Either we're doing recover for a read failure or degraded write,
* caller should have set error bitmap correctly.
*/
ASSERT(bitmap_weight(rbio->error_bitmap, rbio->nr_sectors));
/* For recovery, we need to read all sectors including P/Q. */
ret = alloc_rbio_pages(rbio);
if (ret < 0)
goto out;
index_rbio_pages(rbio);
/*
* Read everything that hasn't failed. However this time we will
* not trust any cached sector.
* As we may read out some stale data but higher layer is not reading
* that stale part.
*
* So here we always re-read everything in recovery path.
*/
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
int stripe = total_sector_nr / rbio->stripe_nsectors;
int sectornr = total_sector_nr % rbio->stripe_nsectors;
struct sector_ptr *sector;
/*
* Skip the range which has error. It can be a range which is
* marked error (for csum mismatch), or it can be a missing
* device.
*/
if (!rbio->bioc->stripes[stripe].dev->bdev ||
test_bit(total_sector_nr, rbio->error_bitmap)) {
/*
* Also set the error bit for missing device, which
* may not yet have its error bit set.
*/
set_bit(total_sector_nr, rbio->error_bitmap);
continue;
}
sector = rbio_stripe_sector(rbio, stripe, sectornr);
ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
sectornr, REQ_OP_READ);
if (ret < 0) {
bio_list_put(&bio_list);
goto out;
}
}
submit_read_wait_bio_list(rbio, &bio_list);
ret = recover_sectors(rbio);
out:
rbio_orig_end_io(rbio, errno_to_blk_status(ret));
}
static void recover_rbio_work(struct work_struct *work)
{
struct btrfs_raid_bio *rbio;
rbio = container_of(work, struct btrfs_raid_bio, work);
if (!lock_stripe_add(rbio))
recover_rbio(rbio);
}
static void recover_rbio_work_locked(struct work_struct *work)
{
recover_rbio(container_of(work, struct btrfs_raid_bio, work));
}
static void set_rbio_raid6_extra_error(struct btrfs_raid_bio *rbio, int mirror_num)
{
bool found = false;
int sector_nr;
/*
* This is for RAID6 extra recovery tries, thus mirror number should
* be large than 2.
* Mirror 1 means read from data stripes. Mirror 2 means rebuild using
* RAID5 methods.
*/
ASSERT(mirror_num > 2);
for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
int found_errors;
int faila;
int failb;
found_errors = get_rbio_veritical_errors(rbio, sector_nr,
&faila, &failb);
/* This vertical stripe doesn't have errors. */
if (!found_errors)
continue;
/*
* If we found errors, there should be only one error marked
* by previous set_rbio_range_error().
*/
ASSERT(found_errors == 1);
found = true;
/* Now select another stripe to mark as error. */
failb = rbio->real_stripes - (mirror_num - 1);
if (failb <= faila)
failb--;
/* Set the extra bit in error bitmap. */
if (failb >= 0)
set_bit(failb * rbio->stripe_nsectors + sector_nr,
rbio->error_bitmap);
}
/* We should found at least one vertical stripe with error.*/
ASSERT(found);
}
/*
* the main entry point for reads from the higher layers. This
* is really only called when the normal read path had a failure,
* so we assume the bio they send down corresponds to a failed part
* of the drive.
*/
void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
int mirror_num)
{
struct btrfs_fs_info *fs_info = bioc->fs_info;
struct btrfs_raid_bio *rbio;
rbio = alloc_rbio(fs_info, bioc);
if (IS_ERR(rbio)) {
bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
bio_endio(bio);
return;
}
rbio->operation = BTRFS_RBIO_READ_REBUILD;
rbio_add_bio(rbio, bio);
set_rbio_range_error(rbio, bio);
/*
* Loop retry:
* for 'mirror == 2', reconstruct from all other stripes.
* for 'mirror_num > 2', select a stripe to fail on every retry.
*/
if (mirror_num > 2)
set_rbio_raid6_extra_error(rbio, mirror_num);
start_async_work(rbio, recover_rbio_work);
}
static void fill_data_csums(struct btrfs_raid_bio *rbio)
{
struct btrfs_fs_info *fs_info = rbio->bioc->fs_info;
struct btrfs_root *csum_root = btrfs_csum_root(fs_info,
rbio->bioc->full_stripe_logical);
const u64 start = rbio->bioc->full_stripe_logical;
const u32 len = (rbio->nr_data * rbio->stripe_nsectors) <<
fs_info->sectorsize_bits;
int ret;
/* The rbio should not have its csum buffer initialized. */
ASSERT(!rbio->csum_buf && !rbio->csum_bitmap);
/*
* Skip the csum search if:
*
* - The rbio doesn't belong to data block groups
* Then we are doing IO for tree blocks, no need to search csums.
*
* - The rbio belongs to mixed block groups
* This is to avoid deadlock, as we're already holding the full
* stripe lock, if we trigger a metadata read, and it needs to do
* raid56 recovery, we will deadlock.
*/
if (!(rbio->bioc->map_type & BTRFS_BLOCK_GROUP_DATA) ||
rbio->bioc->map_type & BTRFS_BLOCK_GROUP_METADATA)
return;
rbio->csum_buf = kzalloc(rbio->nr_data * rbio->stripe_nsectors *
fs_info->csum_size, GFP_NOFS);
rbio->csum_bitmap = bitmap_zalloc(rbio->nr_data * rbio->stripe_nsectors,
GFP_NOFS);
if (!rbio->csum_buf || !rbio->csum_bitmap) {
ret = -ENOMEM;
goto error;
}
ret = btrfs_lookup_csums_bitmap(csum_root, NULL, start, start + len - 1,
rbio->csum_buf, rbio->csum_bitmap);
if (ret < 0)
goto error;
if (bitmap_empty(rbio->csum_bitmap, len >> fs_info->sectorsize_bits))
goto no_csum;
return;
error:
/*
* We failed to allocate memory or grab the csum, but it's not fatal,
* we can still continue. But better to warn users that RMW is no
* longer safe for this particular sub-stripe write.
*/
btrfs_warn_rl(fs_info,
"sub-stripe write for full stripe %llu is not safe, failed to get csum: %d",
rbio->bioc->full_stripe_logical, ret);
no_csum:
kfree(rbio->csum_buf);
bitmap_free(rbio->csum_bitmap);
rbio->csum_buf = NULL;
rbio->csum_bitmap = NULL;
}
static int rmw_read_wait_recover(struct btrfs_raid_bio *rbio)
{
struct bio_list bio_list = BIO_EMPTY_LIST;
int total_sector_nr;
int ret = 0;
/*
* Fill the data csums we need for data verification. We need to fill
* the csum_bitmap/csum_buf first, as our endio function will try to
* verify the data sectors.
*/
fill_data_csums(rbio);
/*
* Build a list of bios to read all sectors (including data and P/Q).
*
* This behavior is to compensate the later csum verification and recovery.
*/
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
struct sector_ptr *sector;
int stripe = total_sector_nr / rbio->stripe_nsectors;
int sectornr = total_sector_nr % rbio->stripe_nsectors;
sector = rbio_stripe_sector(rbio, stripe, sectornr);
ret = rbio_add_io_sector(rbio, &bio_list, sector,
stripe, sectornr, REQ_OP_READ);
if (ret) {
bio_list_put(&bio_list);
return ret;
}
}
/*
* We may or may not have any corrupted sectors (including missing dev
* and csum mismatch), just let recover_sectors() to handle them all.
*/
submit_read_wait_bio_list(rbio, &bio_list);
return recover_sectors(rbio);
}
static void raid_wait_write_end_io(struct bio *bio)
{
struct btrfs_raid_bio *rbio = bio->bi_private;
blk_status_t err = bio->bi_status;
if (err)
rbio_update_error_bitmap(rbio, bio);
bio_put(bio);
if (atomic_dec_and_test(&rbio->stripes_pending))
wake_up(&rbio->io_wait);
}
static void submit_write_bios(struct btrfs_raid_bio *rbio,
struct bio_list *bio_list)
{
struct bio *bio;
atomic_set(&rbio->stripes_pending, bio_list_size(bio_list));
while ((bio = bio_list_pop(bio_list))) {
bio->bi_end_io = raid_wait_write_end_io;
if (trace_raid56_write_enabled()) {
struct raid56_bio_trace_info trace_info = { 0 };
bio_get_trace_info(rbio, bio, &trace_info);
trace_raid56_write(rbio, bio, &trace_info);
}
submit_bio(bio);
}
}
/*
* To determine if we need to read any sector from the disk.
* Should only be utilized in RMW path, to skip cached rbio.
*/
static bool need_read_stripe_sectors(struct btrfs_raid_bio *rbio)
{
int i;
for (i = 0; i < rbio->nr_data * rbio->stripe_nsectors; i++) {
struct sector_ptr *sector = &rbio->stripe_sectors[i];
/*
* We have a sector which doesn't have page nor uptodate,
* thus this rbio can not be cached one, as cached one must
* have all its data sectors present and uptodate.
*/
if (!sector->page || !sector->uptodate)
return true;
}
return false;
}
static void rmw_rbio(struct btrfs_raid_bio *rbio)
{
struct bio_list bio_list;
int sectornr;
int ret = 0;
/*
* Allocate the pages for parity first, as P/Q pages will always be
* needed for both full-stripe and sub-stripe writes.
*/
ret = alloc_rbio_parity_pages(rbio);
if (ret < 0)
goto out;
/*
* Either full stripe write, or we have every data sector already
* cached, can go to write path immediately.
*/
if (!rbio_is_full(rbio) && need_read_stripe_sectors(rbio)) {
/*
* Now we're doing sub-stripe write, also need all data stripes
* to do the full RMW.
*/
ret = alloc_rbio_data_pages(rbio);
if (ret < 0)
goto out;
index_rbio_pages(rbio);
ret = rmw_read_wait_recover(rbio);
if (ret < 0)
goto out;
}
/*
* At this stage we're not allowed to add any new bios to the
* bio list any more, anyone else that wants to change this stripe
* needs to do their own rmw.
*/
spin_lock(&rbio->bio_list_lock);
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
spin_unlock(&rbio->bio_list_lock);
bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
index_rbio_pages(rbio);
/*
* We don't cache full rbios because we're assuming
* the higher layers are unlikely to use this area of
* the disk again soon. If they do use it again,
* hopefully they will send another full bio.
*/
if (!rbio_is_full(rbio))
cache_rbio_pages(rbio);
else
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
generate_pq_vertical(rbio, sectornr);
bio_list_init(&bio_list);
ret = rmw_assemble_write_bios(rbio, &bio_list);
if (ret < 0)
goto out;
/* We should have at least one bio assembled. */
ASSERT(bio_list_size(&bio_list));
submit_write_bios(rbio, &bio_list);
wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
/* We may have more errors than our tolerance during the read. */
for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) {
int found_errors;
found_errors = get_rbio_veritical_errors(rbio, sectornr, NULL, NULL);
if (found_errors > rbio->bioc->max_errors) {
ret = -EIO;
break;
}
}
out:
rbio_orig_end_io(rbio, errno_to_blk_status(ret));
}
static void rmw_rbio_work(struct work_struct *work)
{
struct btrfs_raid_bio *rbio;
rbio = container_of(work, struct btrfs_raid_bio, work);
if (lock_stripe_add(rbio) == 0)
rmw_rbio(rbio);
}
static void rmw_rbio_work_locked(struct work_struct *work)
{
rmw_rbio(container_of(work, struct btrfs_raid_bio, work));
}
/*
* The following code is used to scrub/replace the parity stripe
*
* Caller must have already increased bio_counter for getting @bioc.
*
* Note: We need make sure all the pages that add into the scrub/replace
* raid bio are correct and not be changed during the scrub/replace. That
* is those pages just hold metadata or file data with checksum.
*/
struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
struct btrfs_io_context *bioc,
struct btrfs_device *scrub_dev,
unsigned long *dbitmap, int stripe_nsectors)
{
struct btrfs_fs_info *fs_info = bioc->fs_info;
struct btrfs_raid_bio *rbio;
int i;
rbio = alloc_rbio(fs_info, bioc);
if (IS_ERR(rbio))
return NULL;
bio_list_add(&rbio->bio_list, bio);
/*
* This is a special bio which is used to hold the completion handler
* and make the scrub rbio is similar to the other types
*/
ASSERT(!bio->bi_iter.bi_size);
rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
/*
* After mapping bioc with BTRFS_MAP_WRITE, parities have been sorted
* to the end position, so this search can start from the first parity
* stripe.
*/
for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
if (bioc->stripes[i].dev == scrub_dev) {
rbio->scrubp = i;
break;
}
}
ASSERT_RBIO_STRIPE(i < rbio->real_stripes, rbio, i);
bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors);
return rbio;
}
/*
* We just scrub the parity that we have correct data on the same horizontal,
* so we needn't allocate all pages for all the stripes.
*/
static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
{
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
int total_sector_nr;
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
struct page *page;
int sectornr = total_sector_nr % rbio->stripe_nsectors;
int index = (total_sector_nr * sectorsize) >> PAGE_SHIFT;
if (!test_bit(sectornr, &rbio->dbitmap))
continue;
if (rbio->stripe_pages[index])
continue;
page = alloc_page(GFP_NOFS);
if (!page)
return -ENOMEM;
rbio->stripe_pages[index] = page;
}
index_stripe_sectors(rbio);
return 0;
}
static int finish_parity_scrub(struct btrfs_raid_bio *rbio)
{
struct btrfs_io_context *bioc = rbio->bioc;
const u32 sectorsize = bioc->fs_info->sectorsize;
void **pointers = rbio->finish_pointers;
unsigned long *pbitmap = &rbio->finish_pbitmap;
int nr_data = rbio->nr_data;
int stripe;
int sectornr;
bool has_qstripe;
struct sector_ptr p_sector = { 0 };
struct sector_ptr q_sector = { 0 };
struct bio_list bio_list;
int is_replace = 0;
int ret;
bio_list_init(&bio_list);
if (rbio->real_stripes - rbio->nr_data == 1)
has_qstripe = false;
else if (rbio->real_stripes - rbio->nr_data == 2)
has_qstripe = true;
else
BUG();
/*
* Replace is running and our P/Q stripe is being replaced, then we
* need to duplicate the final write to replace target.
*/
if (bioc->replace_nr_stripes && bioc->replace_stripe_src == rbio->scrubp) {
is_replace = 1;
bitmap_copy(pbitmap, &rbio->dbitmap, rbio->stripe_nsectors);
}
/*
* Because the higher layers(scrubber) are unlikely to
* use this area of the disk again soon, so don't cache
* it.
*/
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
p_sector.page = alloc_page(GFP_NOFS);
if (!p_sector.page)
return -ENOMEM;
p_sector.pgoff = 0;
p_sector.uptodate = 1;
if (has_qstripe) {
/* RAID6, allocate and map temp space for the Q stripe */
q_sector.page = alloc_page(GFP_NOFS);
if (!q_sector.page) {
__free_page(p_sector.page);
p_sector.page = NULL;
return -ENOMEM;
}
q_sector.pgoff = 0;
q_sector.uptodate = 1;
pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page);
}
bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
/* Map the parity stripe just once */
pointers[nr_data] = kmap_local_page(p_sector.page);
for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
struct sector_ptr *sector;
void *parity;
/* first collect one page from each data stripe */
for (stripe = 0; stripe < nr_data; stripe++) {
sector = sector_in_rbio(rbio, stripe, sectornr, 0);
pointers[stripe] = kmap_local_page(sector->page) +
sector->pgoff;
}
if (has_qstripe) {
assert_rbio(rbio);
/* RAID6, call the library function to fill in our P/Q */
raid6_call.gen_syndrome(rbio->real_stripes, sectorsize,
pointers);
} else {
/* raid5 */
memcpy(pointers[nr_data], pointers[0], sectorsize);
run_xor(pointers + 1, nr_data - 1, sectorsize);
}
/* Check scrubbing parity and repair it */
sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
parity = kmap_local_page(sector->page) + sector->pgoff;
if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0)
memcpy(parity, pointers[rbio->scrubp], sectorsize);
else
/* Parity is right, needn't writeback */
bitmap_clear(&rbio->dbitmap, sectornr, 1);
kunmap_local(parity);
for (stripe = nr_data - 1; stripe >= 0; stripe--)
kunmap_local(pointers[stripe]);
}
kunmap_local(pointers[nr_data]);
__free_page(p_sector.page);
p_sector.page = NULL;
if (q_sector.page) {
kunmap_local(pointers[rbio->real_stripes - 1]);
__free_page(q_sector.page);
q_sector.page = NULL;
}
/*
* time to start writing. Make bios for everything from the
* higher layers (the bio_list in our rbio) and our p/q. Ignore
* everything else.
*/
for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) {
struct sector_ptr *sector;
sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
ret = rbio_add_io_sector(rbio, &bio_list, sector, rbio->scrubp,
sectornr, REQ_OP_WRITE);
if (ret)
goto cleanup;
}
if (!is_replace)
goto submit_write;
/*
* Replace is running and our parity stripe needs to be duplicated to
* the target device. Check we have a valid source stripe number.
*/
ASSERT_RBIO(rbio->bioc->replace_stripe_src >= 0, rbio);
for_each_set_bit(sectornr, pbitmap, rbio->stripe_nsectors) {
struct sector_ptr *sector;
sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr);
ret = rbio_add_io_sector(rbio, &bio_list, sector,
rbio->real_stripes,
sectornr, REQ_OP_WRITE);
if (ret)
goto cleanup;
}
submit_write:
submit_write_bios(rbio, &bio_list);
return 0;
cleanup:
bio_list_put(&bio_list);
return ret;
}
static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
{
if (stripe >= 0 && stripe < rbio->nr_data)
return 1;
return 0;
}
static int recover_scrub_rbio(struct btrfs_raid_bio *rbio)
{
void **pointers = NULL;
void **unmap_array = NULL;
int sector_nr;
int ret = 0;
/*
* @pointers array stores the pointer for each sector.
*
* @unmap_array stores copy of pointers that does not get reordered
* during reconstruction so that kunmap_local works.
*/
pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
if (!pointers || !unmap_array) {
ret = -ENOMEM;
goto out;
}
for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
int dfail = 0, failp = -1;
int faila;
int failb;
int found_errors;
found_errors = get_rbio_veritical_errors(rbio, sector_nr,
&faila, &failb);
if (found_errors > rbio->bioc->max_errors) {
ret = -EIO;
goto out;
}
if (found_errors == 0)
continue;
/* We should have at least one error here. */
ASSERT(faila >= 0 || failb >= 0);
if (is_data_stripe(rbio, faila))
dfail++;
else if (is_parity_stripe(faila))
failp = faila;
if (is_data_stripe(rbio, failb))
dfail++;
else if (is_parity_stripe(failb))
failp = failb;
/*
* Because we can not use a scrubbing parity to repair the
* data, so the capability of the repair is declined. (In the
* case of RAID5, we can not repair anything.)
*/
if (dfail > rbio->bioc->max_errors - 1) {
ret = -EIO;
goto out;
}
/*
* If all data is good, only parity is correctly, just repair
* the parity, no need to recover data stripes.
*/
if (dfail == 0)
continue;
/*
* Here means we got one corrupted data stripe and one
* corrupted parity on RAID6, if the corrupted parity is
* scrubbing parity, luckily, use the other one to repair the
* data, or we can not repair the data stripe.
*/
if (failp != rbio->scrubp) {
ret = -EIO;
goto out;
}
ret = recover_vertical(rbio, sector_nr, pointers, unmap_array);
if (ret < 0)
goto out;
}
out:
kfree(pointers);
kfree(unmap_array);
return ret;
}
static int scrub_assemble_read_bios(struct btrfs_raid_bio *rbio)
{
struct bio_list bio_list = BIO_EMPTY_LIST;
int total_sector_nr;
int ret = 0;
/* Build a list of bios to read all the missing parts. */
for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
total_sector_nr++) {
int sectornr = total_sector_nr % rbio->stripe_nsectors;
int stripe = total_sector_nr / rbio->stripe_nsectors;
struct sector_ptr *sector;
/* No data in the vertical stripe, no need to read. */
if (!test_bit(sectornr, &rbio->dbitmap))
continue;
/*
* We want to find all the sectors missing from the rbio and
* read them from the disk. If sector_in_rbio() finds a sector
* in the bio list we don't need to read it off the stripe.
*/
sector = sector_in_rbio(rbio, stripe, sectornr, 1);
if (sector)
continue;
sector = rbio_stripe_sector(rbio, stripe, sectornr);
/*
* The bio cache may have handed us an uptodate sector. If so,
* use it.
*/
if (sector->uptodate)
continue;
ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
sectornr, REQ_OP_READ);
if (ret) {
bio_list_put(&bio_list);
return ret;
}
}
submit_read_wait_bio_list(rbio, &bio_list);
return 0;
}
static void scrub_rbio(struct btrfs_raid_bio *rbio)
{
int sector_nr;
int ret;
ret = alloc_rbio_essential_pages(rbio);
if (ret)
goto out;
bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors);
ret = scrub_assemble_read_bios(rbio);
if (ret < 0)
goto out;
/* We may have some failures, recover the failed sectors first. */
ret = recover_scrub_rbio(rbio);
if (ret < 0)
goto out;
/*
* We have every sector properly prepared. Can finish the scrub
* and writeback the good content.
*/
ret = finish_parity_scrub(rbio);
wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0);
for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) {
int found_errors;
found_errors = get_rbio_veritical_errors(rbio, sector_nr, NULL, NULL);
if (found_errors > rbio->bioc->max_errors) {
ret = -EIO;
break;
}
}
out:
rbio_orig_end_io(rbio, errno_to_blk_status(ret));
}
static void scrub_rbio_work_locked(struct work_struct *work)
{
scrub_rbio(container_of(work, struct btrfs_raid_bio, work));
}
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
{
if (!lock_stripe_add(rbio))
start_async_work(rbio, scrub_rbio_work_locked);
}
/*
* This is for scrub call sites where we already have correct data contents.
* This allows us to avoid reading data stripes again.
*
* Unfortunately here we have to do page copy, other than reusing the pages.
* This is due to the fact rbio has its own page management for its cache.
*/
void raid56_parity_cache_data_pages(struct btrfs_raid_bio *rbio,
struct page **data_pages, u64 data_logical)
{
const u64 offset_in_full_stripe = data_logical -
rbio->bioc->full_stripe_logical;
const int page_index = offset_in_full_stripe >> PAGE_SHIFT;
const u32 sectorsize = rbio->bioc->fs_info->sectorsize;
const u32 sectors_per_page = PAGE_SIZE / sectorsize;
int ret;
/*
* If we hit ENOMEM temporarily, but later at
* raid56_parity_submit_scrub_rbio() time it succeeded, we just do
* the extra read, not a big deal.
*
* If we hit ENOMEM later at raid56_parity_submit_scrub_rbio() time,
* the bio would got proper error number set.
*/
ret = alloc_rbio_data_pages(rbio);
if (ret < 0)
return;
/* data_logical must be at stripe boundary and inside the full stripe. */
ASSERT(IS_ALIGNED(offset_in_full_stripe, BTRFS_STRIPE_LEN));
ASSERT(offset_in_full_stripe < (rbio->nr_data << BTRFS_STRIPE_LEN_SHIFT));
for (int page_nr = 0; page_nr < (BTRFS_STRIPE_LEN >> PAGE_SHIFT); page_nr++) {
struct page *dst = rbio->stripe_pages[page_nr + page_index];
struct page *src = data_pages[page_nr];
memcpy_page(dst, 0, src, 0, PAGE_SIZE);
for (int sector_nr = sectors_per_page * page_index;
sector_nr < sectors_per_page * (page_index + 1);
sector_nr++)
rbio->stripe_sectors[sector_nr].uptodate = true;
}
}
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