linux/drivers/md/raid5-ppl.c
Logan Gunthorpe f34fdcd4a0 md/raid5-ppl: Fix argument order in bio_alloc_bioset()
bio_alloc_bioset() takes a block device, number of vectors, the
OP flags, the GFP mask and the bio set. However when the prototype
was changed, the callisite in ppl_do_flush() had the OP flags and
the GFP flags reversed. This introduced some sparse error:

  drivers/md/raid5-ppl.c:632:57: warning: incorrect type in argument 3
				    (different base types)
  drivers/md/raid5-ppl.c:632:57:    expected unsigned int opf
  drivers/md/raid5-ppl.c:632:57:    got restricted gfp_t [usertype]
  drivers/md/raid5-ppl.c:633:61: warning: incorrect type in argument 4
  				    (different base types)
  drivers/md/raid5-ppl.c:633:61:    expected restricted gfp_t [usertype]
				    gfp_mask
  drivers/md/raid5-ppl.c:633:61:    got unsigned long long

The sparse error introduction may not have been reported correctly by
0day due to other work that was cleaning up other sparse errors in this
area.

Fixes: 609be10667 ("block: pass a block_device and opf to bio_alloc_bioset")
Cc: stable@vger.kernel.org # 5.18+
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
2022-06-15 10:32:48 -07:00

1533 lines
42 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Partial Parity Log for closing the RAID5 write hole
* Copyright (c) 2017, Intel Corporation.
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/crc32c.h>
#include <linux/async_tx.h>
#include <linux/raid/md_p.h>
#include "md.h"
#include "raid5.h"
#include "raid5-log.h"
/*
* PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
* partial parity data. The header contains an array of entries
* (struct ppl_header_entry) which describe the logged write requests.
* Partial parity for the entries comes after the header, written in the same
* sequence as the entries:
*
* Header
* entry0
* ...
* entryN
* PP data
* PP for entry0
* ...
* PP for entryN
*
* An entry describes one or more consecutive stripe_heads, up to a full
* stripe. The modifed raid data chunks form an m-by-n matrix, where m is the
* number of stripe_heads in the entry and n is the number of modified data
* disks. Every stripe_head in the entry must write to the same data disks.
* An example of a valid case described by a single entry (writes to the first
* stripe of a 4 disk array, 16k chunk size):
*
* sh->sector dd0 dd1 dd2 ppl
* +-----+-----+-----+
* 0 | --- | --- | --- | +----+
* 8 | -W- | -W- | --- | | pp | data_sector = 8
* 16 | -W- | -W- | --- | | pp | data_size = 3 * 2 * 4k
* 24 | -W- | -W- | --- | | pp | pp_size = 3 * 4k
* +-----+-----+-----+ +----+
*
* data_sector is the first raid sector of the modified data, data_size is the
* total size of modified data and pp_size is the size of partial parity for
* this entry. Entries for full stripe writes contain no partial parity
* (pp_size = 0), they only mark the stripes for which parity should be
* recalculated after an unclean shutdown. Every entry holds a checksum of its
* partial parity, the header also has a checksum of the header itself.
*
* A write request is always logged to the PPL instance stored on the parity
* disk of the corresponding stripe. For each member disk there is one ppl_log
* used to handle logging for this disk, independently from others. They are
* grouped in child_logs array in struct ppl_conf, which is assigned to
* r5conf->log_private.
*
* ppl_io_unit represents a full PPL write, header_page contains the ppl_header.
* PPL entries for logged stripes are added in ppl_log_stripe(). A stripe_head
* can be appended to the last entry if it meets the conditions for a valid
* entry described above, otherwise a new entry is added. Checksums of entries
* are calculated incrementally as stripes containing partial parity are being
* added. ppl_submit_iounit() calculates the checksum of the header and submits
* a bio containing the header page and partial parity pages (sh->ppl_page) for
* all stripes of the io_unit. When the PPL write completes, the stripes
* associated with the io_unit are released and raid5d starts writing their data
* and parity. When all stripes are written, the io_unit is freed and the next
* can be submitted.
*
* An io_unit is used to gather stripes until it is submitted or becomes full
* (if the maximum number of entries or size of PPL is reached). Another io_unit
* can't be submitted until the previous has completed (PPL and stripe
* data+parity is written). The log->io_list tracks all io_units of a log
* (for a single member disk). New io_units are added to the end of the list
* and the first io_unit is submitted, if it is not submitted already.
* The current io_unit accepting new stripes is always at the end of the list.
*
* If write-back cache is enabled for any of the disks in the array, its data
* must be flushed before next io_unit is submitted.
*/
#define PPL_SPACE_SIZE (128 * 1024)
struct ppl_conf {
struct mddev *mddev;
/* array of child logs, one for each raid disk */
struct ppl_log *child_logs;
int count;
int block_size; /* the logical block size used for data_sector
* in ppl_header_entry */
u32 signature; /* raid array identifier */
atomic64_t seq; /* current log write sequence number */
struct kmem_cache *io_kc;
mempool_t io_pool;
struct bio_set bs;
struct bio_set flush_bs;
/* used only for recovery */
int recovered_entries;
int mismatch_count;
/* stripes to retry if failed to allocate io_unit */
struct list_head no_mem_stripes;
spinlock_t no_mem_stripes_lock;
unsigned short write_hint;
};
struct ppl_log {
struct ppl_conf *ppl_conf; /* shared between all log instances */
struct md_rdev *rdev; /* array member disk associated with
* this log instance */
struct mutex io_mutex;
struct ppl_io_unit *current_io; /* current io_unit accepting new data
* always at the end of io_list */
spinlock_t io_list_lock;
struct list_head io_list; /* all io_units of this log */
sector_t next_io_sector;
unsigned int entry_space;
bool use_multippl;
bool wb_cache_on;
unsigned long disk_flush_bitmap;
};
#define PPL_IO_INLINE_BVECS 32
struct ppl_io_unit {
struct ppl_log *log;
struct page *header_page; /* for ppl_header */
unsigned int entries_count; /* number of entries in ppl_header */
unsigned int pp_size; /* total size current of partial parity */
u64 seq; /* sequence number of this log write */
struct list_head log_sibling; /* log->io_list */
struct list_head stripe_list; /* stripes added to the io_unit */
atomic_t pending_stripes; /* how many stripes not written to raid */
atomic_t pending_flushes; /* how many disk flushes are in progress */
bool submitted; /* true if write to log started */
/* inline bio and its biovec for submitting the iounit */
struct bio bio;
struct bio_vec biovec[PPL_IO_INLINE_BVECS];
};
struct dma_async_tx_descriptor *
ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **srcs = percpu->scribble;
int count = 0, pd_idx = sh->pd_idx, i;
struct async_submit_ctl submit;
pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
/*
* Partial parity is the XOR of stripe data chunks that are not changed
* during the write request. Depending on available data
* (read-modify-write vs. reconstruct-write case) we calculate it
* differently.
*/
if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
/*
* rmw: xor old data and parity from updated disks
* This is calculated earlier by ops_run_prexor5() so just copy
* the parity dev page.
*/
srcs[count++] = sh->dev[pd_idx].page;
} else if (sh->reconstruct_state == reconstruct_state_drain_run) {
/* rcw: xor data from all not updated disks */
for (i = disks; i--;) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_UPTODATE, &dev->flags))
srcs[count++] = dev->page;
}
} else {
return tx;
}
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, tx,
NULL, sh, (void *) (srcs + sh->disks + 2));
if (count == 1)
tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,
&submit);
else
tx = async_xor(sh->ppl_page, srcs, 0, count, PAGE_SIZE,
&submit);
return tx;
}
static void *ppl_io_pool_alloc(gfp_t gfp_mask, void *pool_data)
{
struct kmem_cache *kc = pool_data;
struct ppl_io_unit *io;
io = kmem_cache_alloc(kc, gfp_mask);
if (!io)
return NULL;
io->header_page = alloc_page(gfp_mask);
if (!io->header_page) {
kmem_cache_free(kc, io);
return NULL;
}
return io;
}
static void ppl_io_pool_free(void *element, void *pool_data)
{
struct kmem_cache *kc = pool_data;
struct ppl_io_unit *io = element;
__free_page(io->header_page);
kmem_cache_free(kc, io);
}
static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
struct stripe_head *sh)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct ppl_io_unit *io;
struct ppl_header *pplhdr;
struct page *header_page;
io = mempool_alloc(&ppl_conf->io_pool, GFP_NOWAIT);
if (!io)
return NULL;
header_page = io->header_page;
memset(io, 0, sizeof(*io));
io->header_page = header_page;
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
atomic_set(&io->pending_stripes, 0);
atomic_set(&io->pending_flushes, 0);
bio_init(&io->bio, log->rdev->bdev, io->biovec, PPL_IO_INLINE_BVECS,
REQ_OP_WRITE | REQ_FUA);
pplhdr = page_address(io->header_page);
clear_page(pplhdr);
memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
pplhdr->signature = cpu_to_le32(ppl_conf->signature);
io->seq = atomic64_add_return(1, &ppl_conf->seq);
pplhdr->generation = cpu_to_le64(io->seq);
return io;
}
static int ppl_log_stripe(struct ppl_log *log, struct stripe_head *sh)
{
struct ppl_io_unit *io = log->current_io;
struct ppl_header_entry *e = NULL;
struct ppl_header *pplhdr;
int i;
sector_t data_sector = 0;
int data_disks = 0;
struct r5conf *conf = sh->raid_conf;
pr_debug("%s: stripe: %llu\n", __func__, (unsigned long long)sh->sector);
/* check if current io_unit is full */
if (io && (io->pp_size == log->entry_space ||
io->entries_count == PPL_HDR_MAX_ENTRIES)) {
pr_debug("%s: add io_unit blocked by seq: %llu\n",
__func__, io->seq);
io = NULL;
}
/* add a new unit if there is none or the current is full */
if (!io) {
io = ppl_new_iounit(log, sh);
if (!io)
return -ENOMEM;
spin_lock_irq(&log->io_list_lock);
list_add_tail(&io->log_sibling, &log->io_list);
spin_unlock_irq(&log->io_list_lock);
log->current_io = io;
}
for (i = 0; i < sh->disks; i++) {
struct r5dev *dev = &sh->dev[i];
if (i != sh->pd_idx && test_bit(R5_Wantwrite, &dev->flags)) {
if (!data_disks || dev->sector < data_sector)
data_sector = dev->sector;
data_disks++;
}
}
BUG_ON(!data_disks);
pr_debug("%s: seq: %llu data_sector: %llu data_disks: %d\n", __func__,
io->seq, (unsigned long long)data_sector, data_disks);
pplhdr = page_address(io->header_page);
if (io->entries_count > 0) {
struct ppl_header_entry *last =
&pplhdr->entries[io->entries_count - 1];
struct stripe_head *sh_last = list_last_entry(
&io->stripe_list, struct stripe_head, log_list);
u64 data_sector_last = le64_to_cpu(last->data_sector);
u32 data_size_last = le32_to_cpu(last->data_size);
/*
* Check if we can append the stripe to the last entry. It must
* be just after the last logged stripe and write to the same
* disks. Use bit shift and logarithm to avoid 64-bit division.
*/
if ((sh->sector == sh_last->sector + RAID5_STRIPE_SECTORS(conf)) &&
(data_sector >> ilog2(conf->chunk_sectors) ==
data_sector_last >> ilog2(conf->chunk_sectors)) &&
((data_sector - data_sector_last) * data_disks ==
data_size_last >> 9))
e = last;
}
if (!e) {
e = &pplhdr->entries[io->entries_count++];
e->data_sector = cpu_to_le64(data_sector);
e->parity_disk = cpu_to_le32(sh->pd_idx);
e->checksum = cpu_to_le32(~0);
}
le32_add_cpu(&e->data_size, data_disks << PAGE_SHIFT);
/* don't write any PP if full stripe write */
if (!test_bit(STRIPE_FULL_WRITE, &sh->state)) {
le32_add_cpu(&e->pp_size, PAGE_SIZE);
io->pp_size += PAGE_SIZE;
e->checksum = cpu_to_le32(crc32c_le(le32_to_cpu(e->checksum),
page_address(sh->ppl_page),
PAGE_SIZE));
}
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripes);
sh->ppl_io = io;
return 0;
}
int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_io_unit *io = sh->ppl_io;
struct ppl_log *log;
if (io || test_bit(STRIPE_SYNCING, &sh->state) || !sh->ppl_page ||
!test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
!test_bit(R5_Insync, &sh->dev[sh->pd_idx].flags)) {
clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
return -EAGAIN;
}
log = &ppl_conf->child_logs[sh->pd_idx];
mutex_lock(&log->io_mutex);
if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
mutex_unlock(&log->io_mutex);
return -EAGAIN;
}
set_bit(STRIPE_LOG_TRAPPED, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
atomic_inc(&sh->count);
if (ppl_log_stripe(log, sh)) {
spin_lock_irq(&ppl_conf->no_mem_stripes_lock);
list_add_tail(&sh->log_list, &ppl_conf->no_mem_stripes);
spin_unlock_irq(&ppl_conf->no_mem_stripes_lock);
}
mutex_unlock(&log->io_mutex);
return 0;
}
static void ppl_log_endio(struct bio *bio)
{
struct ppl_io_unit *io = bio->bi_private;
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct stripe_head *sh, *next;
pr_debug("%s: seq: %llu\n", __func__, io->seq);
if (bio->bi_status)
md_error(ppl_conf->mddev, log->rdev);
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
}
static void ppl_submit_iounit_bio(struct ppl_io_unit *io, struct bio *bio)
{
pr_debug("%s: seq: %llu size: %u sector: %llu dev: %pg\n",
__func__, io->seq, bio->bi_iter.bi_size,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_bdev);
submit_bio(bio);
}
static void ppl_submit_iounit(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct ppl_header *pplhdr = page_address(io->header_page);
struct bio *bio = &io->bio;
struct stripe_head *sh;
int i;
bio->bi_private = io;
if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
ppl_log_endio(bio);
return;
}
for (i = 0; i < io->entries_count; i++) {
struct ppl_header_entry *e = &pplhdr->entries[i];
pr_debug("%s: seq: %llu entry: %d data_sector: %llu pp_size: %u data_size: %u\n",
__func__, io->seq, i, le64_to_cpu(e->data_sector),
le32_to_cpu(e->pp_size), le32_to_cpu(e->data_size));
e->data_sector = cpu_to_le64(le64_to_cpu(e->data_sector) >>
ilog2(ppl_conf->block_size >> 9));
e->checksum = cpu_to_le32(~le32_to_cpu(e->checksum));
}
pplhdr->entries_count = cpu_to_le32(io->entries_count);
pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PPL_HEADER_SIZE));
/* Rewind the buffer if current PPL is larger then remaining space */
if (log->use_multippl &&
log->rdev->ppl.sector + log->rdev->ppl.size - log->next_io_sector <
(PPL_HEADER_SIZE + io->pp_size) >> 9)
log->next_io_sector = log->rdev->ppl.sector;
bio->bi_end_io = ppl_log_endio;
bio->bi_iter.bi_sector = log->next_io_sector;
bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
pr_debug("%s: log->current_io_sector: %llu\n", __func__,
(unsigned long long)log->next_io_sector);
if (log->use_multippl)
log->next_io_sector += (PPL_HEADER_SIZE + io->pp_size) >> 9;
WARN_ON(log->disk_flush_bitmap != 0);
list_for_each_entry(sh, &io->stripe_list, log_list) {
for (i = 0; i < sh->disks; i++) {
struct r5dev *dev = &sh->dev[i];
if ((ppl_conf->child_logs[i].wb_cache_on) &&
(test_bit(R5_Wantwrite, &dev->flags))) {
set_bit(i, &log->disk_flush_bitmap);
}
}
/* entries for full stripe writes have no partial parity */
if (test_bit(STRIPE_FULL_WRITE, &sh->state))
continue;
if (!bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0)) {
struct bio *prev = bio;
bio = bio_alloc_bioset(prev->bi_bdev, BIO_MAX_VECS,
prev->bi_opf, GFP_NOIO,
&ppl_conf->bs);
bio->bi_iter.bi_sector = bio_end_sector(prev);
bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
bio_chain(bio, prev);
ppl_submit_iounit_bio(io, prev);
}
}
ppl_submit_iounit_bio(io, bio);
}
static void ppl_submit_current_io(struct ppl_log *log)
{
struct ppl_io_unit *io;
spin_lock_irq(&log->io_list_lock);
io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
log_sibling);
if (io && io->submitted)
io = NULL;
spin_unlock_irq(&log->io_list_lock);
if (io) {
io->submitted = true;
if (io == log->current_io)
log->current_io = NULL;
ppl_submit_iounit(io);
}
}
void ppl_write_stripe_run(struct r5conf *conf)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_log *log;
int i;
for (i = 0; i < ppl_conf->count; i++) {
log = &ppl_conf->child_logs[i];
mutex_lock(&log->io_mutex);
ppl_submit_current_io(log);
mutex_unlock(&log->io_mutex);
}
}
static void ppl_io_unit_finished(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
unsigned long flags;
pr_debug("%s: seq: %llu\n", __func__, io->seq);
local_irq_save(flags);
spin_lock(&log->io_list_lock);
list_del(&io->log_sibling);
spin_unlock(&log->io_list_lock);
mempool_free(io, &ppl_conf->io_pool);
spin_lock(&ppl_conf->no_mem_stripes_lock);
if (!list_empty(&ppl_conf->no_mem_stripes)) {
struct stripe_head *sh;
sh = list_first_entry(&ppl_conf->no_mem_stripes,
struct stripe_head, log_list);
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
spin_unlock(&ppl_conf->no_mem_stripes_lock);
local_irq_restore(flags);
wake_up(&conf->wait_for_quiescent);
}
static void ppl_flush_endio(struct bio *bio)
{
struct ppl_io_unit *io = bio->bi_private;
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
pr_debug("%s: dev: %pg\n", __func__, bio->bi_bdev);
if (bio->bi_status) {
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_rcu(conf->mddev, bio_dev(bio));
if (rdev)
md_error(rdev->mddev, rdev);
rcu_read_unlock();
}
bio_put(bio);
if (atomic_dec_and_test(&io->pending_flushes)) {
ppl_io_unit_finished(io);
md_wakeup_thread(conf->mddev->thread);
}
}
static void ppl_do_flush(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
int raid_disks = conf->raid_disks;
int flushed_disks = 0;
int i;
atomic_set(&io->pending_flushes, raid_disks);
for_each_set_bit(i, &log->disk_flush_bitmap, raid_disks) {
struct md_rdev *rdev;
struct block_device *bdev = NULL;
rcu_read_lock();
rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && !test_bit(Faulty, &rdev->flags))
bdev = rdev->bdev;
rcu_read_unlock();
if (bdev) {
struct bio *bio;
bio = bio_alloc_bioset(bdev, 0,
REQ_OP_WRITE | REQ_PREFLUSH,
GFP_NOIO, &ppl_conf->flush_bs);
bio->bi_private = io;
bio->bi_end_io = ppl_flush_endio;
pr_debug("%s: dev: %ps\n", __func__, bio->bi_bdev);
submit_bio(bio);
flushed_disks++;
}
}
log->disk_flush_bitmap = 0;
for (i = flushed_disks ; i < raid_disks; i++) {
if (atomic_dec_and_test(&io->pending_flushes))
ppl_io_unit_finished(io);
}
}
static inline bool ppl_no_io_unit_submitted(struct r5conf *conf,
struct ppl_log *log)
{
struct ppl_io_unit *io;
io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
log_sibling);
return !io || !io->submitted;
}
void ppl_quiesce(struct r5conf *conf, int quiesce)
{
struct ppl_conf *ppl_conf = conf->log_private;
int i;
if (quiesce) {
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
spin_lock_irq(&log->io_list_lock);
wait_event_lock_irq(conf->wait_for_quiescent,
ppl_no_io_unit_submitted(conf, log),
log->io_list_lock);
spin_unlock_irq(&log->io_list_lock);
}
}
}
int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio)
{
if (bio->bi_iter.bi_size == 0) {
bio_endio(bio);
return 0;
}
bio->bi_opf &= ~REQ_PREFLUSH;
return -EAGAIN;
}
void ppl_stripe_write_finished(struct stripe_head *sh)
{
struct ppl_io_unit *io;
io = sh->ppl_io;
sh->ppl_io = NULL;
if (io && atomic_dec_and_test(&io->pending_stripes)) {
if (io->log->disk_flush_bitmap)
ppl_do_flush(io);
else
ppl_io_unit_finished(io);
}
}
static void ppl_xor(int size, struct page *page1, struct page *page2)
{
struct async_submit_ctl submit;
struct dma_async_tx_descriptor *tx;
struct page *xor_srcs[] = { page1, page2 };
init_async_submit(&submit, ASYNC_TX_ACK|ASYNC_TX_XOR_DROP_DST,
NULL, NULL, NULL, NULL);
tx = async_xor(page1, xor_srcs, 0, 2, size, &submit);
async_tx_quiesce(&tx);
}
/*
* PPL recovery strategy: xor partial parity and data from all modified data
* disks within a stripe and write the result as the new stripe parity. If all
* stripe data disks are modified (full stripe write), no partial parity is
* available, so just xor the data disks.
*
* Recovery of a PPL entry shall occur only if all modified data disks are
* available and read from all of them succeeds.
*
* A PPL entry applies to a stripe, partial parity size for an entry is at most
* the size of the chunk. Examples of possible cases for a single entry:
*
* case 0: single data disk write:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | +----+ | (no change) |
* | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
* | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
* | ------ | ------ | ------ | +----+ | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = data_size
*
* case 1: more than one data disk write:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | +----+ | (no change) |
* | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
* | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
* | ------ | ------ | ------ | +----+ | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = data_size / modified_data_disks
*
* case 2: write to all data disks (also full stripe write):
* data0 data1 data2 parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | | (no change) |
* | -data- | -data- | -data- | --------> | xor all data |
* | ------ | ------ | ------ | --------> | (no change) |
* | ------ | ------ | ------ | | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = 0
*
* The following cases are possible only in other implementations. The recovery
* code can handle them, but they are not generated at runtime because they can
* be reduced to cases 0, 1 and 2:
*
* case 3:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +----+ +--------------------+
* | ------ | -data- | -data- | | pp | | data1 ^ data2 ^ pp |
* | ------ | -data- | -data- | | pp | -> | data1 ^ data2 ^ pp |
* | -data- | -data- | -data- | | -- | -> | xor all data |
* | -data- | -data- | ------ | | pp | | data0 ^ data1 ^ pp |
* +--------+--------+--------+ +----+ +--------------------+
* pp_size = chunk_size
*
* case 4:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +----+ +--------------------+
* | ------ | -data- | ------ | | pp | | data1 ^ pp |
* | ------ | ------ | ------ | | -- | -> | (no change) |
* | ------ | ------ | ------ | | -- | -> | (no change) |
* | -data- | ------ | ------ | | pp | | data0 ^ pp |
* +--------+--------+--------+ +----+ +--------------------+
* pp_size = chunk_size
*/
static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
sector_t ppl_sector)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct mddev *mddev = ppl_conf->mddev;
struct r5conf *conf = mddev->private;
int block_size = ppl_conf->block_size;
struct page *page1;
struct page *page2;
sector_t r_sector_first;
sector_t r_sector_last;
int strip_sectors;
int data_disks;
int i;
int ret = 0;
unsigned int pp_size = le32_to_cpu(e->pp_size);
unsigned int data_size = le32_to_cpu(e->data_size);
page1 = alloc_page(GFP_KERNEL);
page2 = alloc_page(GFP_KERNEL);
if (!page1 || !page2) {
ret = -ENOMEM;
goto out;
}
r_sector_first = le64_to_cpu(e->data_sector) * (block_size >> 9);
if ((pp_size >> 9) < conf->chunk_sectors) {
if (pp_size > 0) {
data_disks = data_size / pp_size;
strip_sectors = pp_size >> 9;
} else {
data_disks = conf->raid_disks - conf->max_degraded;
strip_sectors = (data_size >> 9) / data_disks;
}
r_sector_last = r_sector_first +
(data_disks - 1) * conf->chunk_sectors +
strip_sectors;
} else {
data_disks = conf->raid_disks - conf->max_degraded;
strip_sectors = conf->chunk_sectors;
r_sector_last = r_sector_first + (data_size >> 9);
}
pr_debug("%s: array sector first: %llu last: %llu\n", __func__,
(unsigned long long)r_sector_first,
(unsigned long long)r_sector_last);
/* if start and end is 4k aligned, use a 4k block */
if (block_size == 512 &&
(r_sector_first & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0 &&
(r_sector_last & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0)
block_size = RAID5_STRIPE_SIZE(conf);
/* iterate through blocks in strip */
for (i = 0; i < strip_sectors; i += (block_size >> 9)) {
bool update_parity = false;
sector_t parity_sector;
struct md_rdev *parity_rdev;
struct stripe_head sh;
int disk;
int indent = 0;
pr_debug("%s:%*s iter %d start\n", __func__, indent, "", i);
indent += 2;
memset(page_address(page1), 0, PAGE_SIZE);
/* iterate through data member disks */
for (disk = 0; disk < data_disks; disk++) {
int dd_idx;
struct md_rdev *rdev;
sector_t sector;
sector_t r_sector = r_sector_first + i +
(disk * conf->chunk_sectors);
pr_debug("%s:%*s data member disk %d start\n",
__func__, indent, "", disk);
indent += 2;
if (r_sector >= r_sector_last) {
pr_debug("%s:%*s array sector %llu doesn't need parity update\n",
__func__, indent, "",
(unsigned long long)r_sector);
indent -= 2;
continue;
}
update_parity = true;
/* map raid sector to member disk */
sector = raid5_compute_sector(conf, r_sector, 0,
&dd_idx, NULL);
pr_debug("%s:%*s processing array sector %llu => data member disk %d, sector %llu\n",
__func__, indent, "",
(unsigned long long)r_sector, dd_idx,
(unsigned long long)sector);
/* Array has not started so rcu dereference is safe */
rdev = rcu_dereference_protected(
conf->disks[dd_idx].rdev, 1);
if (!rdev || (!test_bit(In_sync, &rdev->flags) &&
sector >= rdev->recovery_offset)) {
pr_debug("%s:%*s data member disk %d missing\n",
__func__, indent, "", dd_idx);
update_parity = false;
break;
}
pr_debug("%s:%*s reading data member disk %pg sector %llu\n",
__func__, indent, "", rdev->bdev,
(unsigned long long)sector);
if (!sync_page_io(rdev, sector, block_size, page2,
REQ_OP_READ, 0, false)) {
md_error(mddev, rdev);
pr_debug("%s:%*s read failed!\n", __func__,
indent, "");
ret = -EIO;
goto out;
}
ppl_xor(block_size, page1, page2);
indent -= 2;
}
if (!update_parity)
continue;
if (pp_size > 0) {
pr_debug("%s:%*s reading pp disk sector %llu\n",
__func__, indent, "",
(unsigned long long)(ppl_sector + i));
if (!sync_page_io(log->rdev,
ppl_sector - log->rdev->data_offset + i,
block_size, page2, REQ_OP_READ, 0,
false)) {
pr_debug("%s:%*s read failed!\n", __func__,
indent, "");
md_error(mddev, log->rdev);
ret = -EIO;
goto out;
}
ppl_xor(block_size, page1, page2);
}
/* map raid sector to parity disk */
parity_sector = raid5_compute_sector(conf, r_sector_first + i,
0, &disk, &sh);
BUG_ON(sh.pd_idx != le32_to_cpu(e->parity_disk));
/* Array has not started so rcu dereference is safe */
parity_rdev = rcu_dereference_protected(
conf->disks[sh.pd_idx].rdev, 1);
BUG_ON(parity_rdev->bdev->bd_dev != log->rdev->bdev->bd_dev);
pr_debug("%s:%*s write parity at sector %llu, disk %pg\n",
__func__, indent, "",
(unsigned long long)parity_sector,
parity_rdev->bdev);
if (!sync_page_io(parity_rdev, parity_sector, block_size,
page1, REQ_OP_WRITE, 0, false)) {
pr_debug("%s:%*s parity write error!\n", __func__,
indent, "");
md_error(mddev, parity_rdev);
ret = -EIO;
goto out;
}
}
out:
if (page1)
__free_page(page1);
if (page2)
__free_page(page2);
return ret;
}
static int ppl_recover(struct ppl_log *log, struct ppl_header *pplhdr,
sector_t offset)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct md_rdev *rdev = log->rdev;
struct mddev *mddev = rdev->mddev;
sector_t ppl_sector = rdev->ppl.sector + offset +
(PPL_HEADER_SIZE >> 9);
struct page *page;
int i;
int ret = 0;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
/* iterate through all PPL entries saved */
for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++) {
struct ppl_header_entry *e = &pplhdr->entries[i];
u32 pp_size = le32_to_cpu(e->pp_size);
sector_t sector = ppl_sector;
int ppl_entry_sectors = pp_size >> 9;
u32 crc, crc_stored;
pr_debug("%s: disk: %d entry: %d ppl_sector: %llu pp_size: %u\n",
__func__, rdev->raid_disk, i,
(unsigned long long)ppl_sector, pp_size);
crc = ~0;
crc_stored = le32_to_cpu(e->checksum);
/* read parial parity for this entry and calculate its checksum */
while (pp_size) {
int s = pp_size > PAGE_SIZE ? PAGE_SIZE : pp_size;
if (!sync_page_io(rdev, sector - rdev->data_offset,
s, page, REQ_OP_READ, 0, false)) {
md_error(mddev, rdev);
ret = -EIO;
goto out;
}
crc = crc32c_le(crc, page_address(page), s);
pp_size -= s;
sector += s >> 9;
}
crc = ~crc;
if (crc != crc_stored) {
/*
* Don't recover this entry if the checksum does not
* match, but keep going and try to recover other
* entries.
*/
pr_debug("%s: ppl entry crc does not match: stored: 0x%x calculated: 0x%x\n",
__func__, crc_stored, crc);
ppl_conf->mismatch_count++;
} else {
ret = ppl_recover_entry(log, e, ppl_sector);
if (ret)
goto out;
ppl_conf->recovered_entries++;
}
ppl_sector += ppl_entry_sectors;
}
/* flush the disk cache after recovery if necessary */
ret = blkdev_issue_flush(rdev->bdev);
out:
__free_page(page);
return ret;
}
static int ppl_write_empty_header(struct ppl_log *log)
{
struct page *page;
struct ppl_header *pplhdr;
struct md_rdev *rdev = log->rdev;
int ret = 0;
pr_debug("%s: disk: %d ppl_sector: %llu\n", __func__,
rdev->raid_disk, (unsigned long long)rdev->ppl.sector);
page = alloc_page(GFP_NOIO | __GFP_ZERO);
if (!page)
return -ENOMEM;
pplhdr = page_address(page);
/* zero out PPL space to avoid collision with old PPLs */
blkdev_issue_zeroout(rdev->bdev, rdev->ppl.sector,
log->rdev->ppl.size, GFP_NOIO, 0);
memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
pplhdr->signature = cpu_to_le32(log->ppl_conf->signature);
pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PAGE_SIZE));
if (!sync_page_io(rdev, rdev->ppl.sector - rdev->data_offset,
PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_SYNC |
REQ_FUA, 0, false)) {
md_error(rdev->mddev, rdev);
ret = -EIO;
}
__free_page(page);
return ret;
}
static int ppl_load_distributed(struct ppl_log *log)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct md_rdev *rdev = log->rdev;
struct mddev *mddev = rdev->mddev;
struct page *page, *page2;
struct ppl_header *pplhdr = NULL, *prev_pplhdr = NULL;
u32 crc, crc_stored;
u32 signature;
int ret = 0, i;
sector_t pplhdr_offset = 0, prev_pplhdr_offset = 0;
pr_debug("%s: disk: %d\n", __func__, rdev->raid_disk);
/* read PPL headers, find the recent one */
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
page2 = alloc_page(GFP_KERNEL);
if (!page2) {
__free_page(page);
return -ENOMEM;
}
/* searching ppl area for latest ppl */
while (pplhdr_offset < rdev->ppl.size - (PPL_HEADER_SIZE >> 9)) {
if (!sync_page_io(rdev,
rdev->ppl.sector - rdev->data_offset +
pplhdr_offset, PAGE_SIZE, page, REQ_OP_READ,
0, false)) {
md_error(mddev, rdev);
ret = -EIO;
/* if not able to read - don't recover any PPL */
pplhdr = NULL;
break;
}
pplhdr = page_address(page);
/* check header validity */
crc_stored = le32_to_cpu(pplhdr->checksum);
pplhdr->checksum = 0;
crc = ~crc32c_le(~0, pplhdr, PAGE_SIZE);
if (crc_stored != crc) {
pr_debug("%s: ppl header crc does not match: stored: 0x%x calculated: 0x%x (offset: %llu)\n",
__func__, crc_stored, crc,
(unsigned long long)pplhdr_offset);
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
signature = le32_to_cpu(pplhdr->signature);
if (mddev->external) {
/*
* For external metadata the header signature is set and
* validated in userspace.
*/
ppl_conf->signature = signature;
} else if (ppl_conf->signature != signature) {
pr_debug("%s: ppl header signature does not match: stored: 0x%x configured: 0x%x (offset: %llu)\n",
__func__, signature, ppl_conf->signature,
(unsigned long long)pplhdr_offset);
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
if (prev_pplhdr && le64_to_cpu(prev_pplhdr->generation) >
le64_to_cpu(pplhdr->generation)) {
/* previous was newest */
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
prev_pplhdr_offset = pplhdr_offset;
prev_pplhdr = pplhdr;
swap(page, page2);
/* calculate next potential ppl offset */
for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++)
pplhdr_offset +=
le32_to_cpu(pplhdr->entries[i].pp_size) >> 9;
pplhdr_offset += PPL_HEADER_SIZE >> 9;
}
/* no valid ppl found */
if (!pplhdr)
ppl_conf->mismatch_count++;
else
pr_debug("%s: latest PPL found at offset: %llu, with generation: %llu\n",
__func__, (unsigned long long)pplhdr_offset,
le64_to_cpu(pplhdr->generation));
/* attempt to recover from log if we are starting a dirty array */
if (pplhdr && !mddev->pers && mddev->recovery_cp != MaxSector)
ret = ppl_recover(log, pplhdr, pplhdr_offset);
/* write empty header if we are starting the array */
if (!ret && !mddev->pers)
ret = ppl_write_empty_header(log);
__free_page(page);
__free_page(page2);
pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
__func__, ret, ppl_conf->mismatch_count,
ppl_conf->recovered_entries);
return ret;
}
static int ppl_load(struct ppl_conf *ppl_conf)
{
int ret = 0;
u32 signature = 0;
bool signature_set = false;
int i;
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
/* skip missing drive */
if (!log->rdev)
continue;
ret = ppl_load_distributed(log);
if (ret)
break;
/*
* For external metadata we can't check if the signature is
* correct on a single drive, but we can check if it is the same
* on all drives.
*/
if (ppl_conf->mddev->external) {
if (!signature_set) {
signature = ppl_conf->signature;
signature_set = true;
} else if (signature != ppl_conf->signature) {
pr_warn("md/raid:%s: PPL header signature does not match on all member drives\n",
mdname(ppl_conf->mddev));
ret = -EINVAL;
break;
}
}
}
pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
__func__, ret, ppl_conf->mismatch_count,
ppl_conf->recovered_entries);
return ret;
}
static void __ppl_exit_log(struct ppl_conf *ppl_conf)
{
clear_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
clear_bit(MD_HAS_MULTIPLE_PPLS, &ppl_conf->mddev->flags);
kfree(ppl_conf->child_logs);
bioset_exit(&ppl_conf->bs);
bioset_exit(&ppl_conf->flush_bs);
mempool_exit(&ppl_conf->io_pool);
kmem_cache_destroy(ppl_conf->io_kc);
kfree(ppl_conf);
}
void ppl_exit_log(struct r5conf *conf)
{
struct ppl_conf *ppl_conf = conf->log_private;
if (ppl_conf) {
__ppl_exit_log(ppl_conf);
conf->log_private = NULL;
}
}
static int ppl_validate_rdev(struct md_rdev *rdev)
{
int ppl_data_sectors;
int ppl_size_new;
/*
* The configured PPL size must be enough to store
* the header and (at the very least) partial parity
* for one stripe. Round it down to ensure the data
* space is cleanly divisible by stripe size.
*/
ppl_data_sectors = rdev->ppl.size - (PPL_HEADER_SIZE >> 9);
if (ppl_data_sectors > 0)
ppl_data_sectors = rounddown(ppl_data_sectors,
RAID5_STRIPE_SECTORS((struct r5conf *)rdev->mddev->private));
if (ppl_data_sectors <= 0) {
pr_warn("md/raid:%s: PPL space too small on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -ENOSPC;
}
ppl_size_new = ppl_data_sectors + (PPL_HEADER_SIZE >> 9);
if ((rdev->ppl.sector < rdev->data_offset &&
rdev->ppl.sector + ppl_size_new > rdev->data_offset) ||
(rdev->ppl.sector >= rdev->data_offset &&
rdev->data_offset + rdev->sectors > rdev->ppl.sector)) {
pr_warn("md/raid:%s: PPL space overlaps with data on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -EINVAL;
}
if (!rdev->mddev->external &&
((rdev->ppl.offset > 0 && rdev->ppl.offset < (rdev->sb_size >> 9)) ||
(rdev->ppl.offset <= 0 && rdev->ppl.offset + ppl_size_new > 0))) {
pr_warn("md/raid:%s: PPL space overlaps with superblock on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -EINVAL;
}
rdev->ppl.size = ppl_size_new;
return 0;
}
static void ppl_init_child_log(struct ppl_log *log, struct md_rdev *rdev)
{
struct request_queue *q;
if ((rdev->ppl.size << 9) >= (PPL_SPACE_SIZE +
PPL_HEADER_SIZE) * 2) {
log->use_multippl = true;
set_bit(MD_HAS_MULTIPLE_PPLS,
&log->ppl_conf->mddev->flags);
log->entry_space = PPL_SPACE_SIZE;
} else {
log->use_multippl = false;
log->entry_space = (log->rdev->ppl.size << 9) -
PPL_HEADER_SIZE;
}
log->next_io_sector = rdev->ppl.sector;
q = bdev_get_queue(rdev->bdev);
if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
log->wb_cache_on = true;
}
int ppl_init_log(struct r5conf *conf)
{
struct ppl_conf *ppl_conf;
struct mddev *mddev = conf->mddev;
int ret = 0;
int max_disks;
int i;
pr_debug("md/raid:%s: enabling distributed Partial Parity Log\n",
mdname(conf->mddev));
if (PAGE_SIZE != 4096)
return -EINVAL;
if (mddev->level != 5) {
pr_warn("md/raid:%s PPL is not compatible with raid level %d\n",
mdname(mddev), mddev->level);
return -EINVAL;
}
if (mddev->bitmap_info.file || mddev->bitmap_info.offset) {
pr_warn("md/raid:%s PPL is not compatible with bitmap\n",
mdname(mddev));
return -EINVAL;
}
if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
pr_warn("md/raid:%s PPL is not compatible with journal\n",
mdname(mddev));
return -EINVAL;
}
max_disks = sizeof_field(struct ppl_log, disk_flush_bitmap) *
BITS_PER_BYTE;
if (conf->raid_disks > max_disks) {
pr_warn("md/raid:%s PPL doesn't support over %d disks in the array\n",
mdname(mddev), max_disks);
return -EINVAL;
}
ppl_conf = kzalloc(sizeof(struct ppl_conf), GFP_KERNEL);
if (!ppl_conf)
return -ENOMEM;
ppl_conf->mddev = mddev;
ppl_conf->io_kc = KMEM_CACHE(ppl_io_unit, 0);
if (!ppl_conf->io_kc) {
ret = -ENOMEM;
goto err;
}
ret = mempool_init(&ppl_conf->io_pool, conf->raid_disks, ppl_io_pool_alloc,
ppl_io_pool_free, ppl_conf->io_kc);
if (ret)
goto err;
ret = bioset_init(&ppl_conf->bs, conf->raid_disks, 0, BIOSET_NEED_BVECS);
if (ret)
goto err;
ret = bioset_init(&ppl_conf->flush_bs, conf->raid_disks, 0, 0);
if (ret)
goto err;
ppl_conf->count = conf->raid_disks;
ppl_conf->child_logs = kcalloc(ppl_conf->count, sizeof(struct ppl_log),
GFP_KERNEL);
if (!ppl_conf->child_logs) {
ret = -ENOMEM;
goto err;
}
atomic64_set(&ppl_conf->seq, 0);
INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
spin_lock_init(&ppl_conf->no_mem_stripes_lock);
if (!mddev->external) {
ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
ppl_conf->block_size = 512;
} else {
ppl_conf->block_size = queue_logical_block_size(mddev->queue);
}
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
/* Array has not started so rcu dereference is safe */
struct md_rdev *rdev =
rcu_dereference_protected(conf->disks[i].rdev, 1);
mutex_init(&log->io_mutex);
spin_lock_init(&log->io_list_lock);
INIT_LIST_HEAD(&log->io_list);
log->ppl_conf = ppl_conf;
log->rdev = rdev;
if (rdev) {
ret = ppl_validate_rdev(rdev);
if (ret)
goto err;
ppl_init_child_log(log, rdev);
}
}
/* load and possibly recover the logs from the member disks */
ret = ppl_load(ppl_conf);
if (ret) {
goto err;
} else if (!mddev->pers && mddev->recovery_cp == 0 &&
ppl_conf->recovered_entries > 0 &&
ppl_conf->mismatch_count == 0) {
/*
* If we are starting a dirty array and the recovery succeeds
* without any issues, set the array as clean.
*/
mddev->recovery_cp = MaxSector;
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
} else if (mddev->pers && ppl_conf->mismatch_count > 0) {
/* no mismatch allowed when enabling PPL for a running array */
ret = -EINVAL;
goto err;
}
conf->log_private = ppl_conf;
set_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
return 0;
err:
__ppl_exit_log(ppl_conf);
return ret;
}
int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_log *log;
int ret = 0;
if (!rdev)
return -EINVAL;
pr_debug("%s: disk: %d operation: %s dev: %pg\n",
__func__, rdev->raid_disk, add ? "add" : "remove",
rdev->bdev);
if (rdev->raid_disk < 0)
return 0;
if (rdev->raid_disk >= ppl_conf->count)
return -ENODEV;
log = &ppl_conf->child_logs[rdev->raid_disk];
mutex_lock(&log->io_mutex);
if (add) {
ret = ppl_validate_rdev(rdev);
if (!ret) {
log->rdev = rdev;
ret = ppl_write_empty_header(log);
ppl_init_child_log(log, rdev);
}
} else {
log->rdev = NULL;
}
mutex_unlock(&log->io_mutex);
return ret;
}
static ssize_t
ppl_write_hint_show(struct mddev *mddev, char *buf)
{
return sprintf(buf, "%d\n", 0);
}
static ssize_t
ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
int err = 0;
unsigned short new;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtou16(page, 10, &new))
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else if (!raid5_has_ppl(conf) || !conf->log_private)
err = -EINVAL;
mddev_unlock(mddev);
return err ?: len;
}
struct md_sysfs_entry
ppl_write_hint = __ATTR(ppl_write_hint, S_IRUGO | S_IWUSR,
ppl_write_hint_show,
ppl_write_hint_store);