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authorShaohua Li <shli@fb.com>2016-12-13 12:40:15 -0800
committerShaohua Li <shli@fb.com>2016-12-13 12:40:15 -0800
commit20737738d397dfadbca1ea50dcc00d7259f500cf (patch)
tree5765b1815331bac9ca32208963c850e60806d6de /drivers/md/raid5-cache.c
parentb78b499a67c3f77aeb6cd0b54724bc38b141255d (diff)
parent2953079c692da067aeb6345659875b97378f9b0a (diff)
Merge branch 'md-next' into md-linus
Diffstat (limited to 'drivers/md/raid5-cache.c')
-rw-r--r--drivers/md/raid5-cache.c1833
1 files changed, 1619 insertions, 214 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 8491edcfb5a6..d7bfb6fc8aef 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2015 Shaohua Li <shli@fb.com>
+ * Copyright (C) 2016 Song Liu <songliubraving@fb.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
@@ -18,8 +19,10 @@
#include <linux/raid/md_p.h>
#include <linux/crc32c.h>
#include <linux/random.h>
+#include <linux/kthread.h>
#include "md.h"
#include "raid5.h"
+#include "bitmap.h"
/*
* metadata/data stored in disk with 4k size unit (a block) regardless
@@ -28,18 +31,70 @@
#define BLOCK_SECTORS (8)
/*
- * reclaim runs every 1/4 disk size or 10G reclaimable space. This can prevent
- * recovery scans a very long log
+ * log->max_free_space is min(1/4 disk size, 10G reclaimable space).
+ *
+ * In write through mode, the reclaim runs every log->max_free_space.
+ * This can prevent the recovery scans for too long
*/
#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
+/* wake up reclaim thread periodically */
+#define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
+/* start flush with these full stripes */
+#define R5C_FULL_STRIPE_FLUSH_BATCH 256
+/* reclaim stripes in groups */
+#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
+
/*
* We only need 2 bios per I/O unit to make progress, but ensure we
* have a few more available to not get too tight.
*/
#define R5L_POOL_SIZE 4
+/*
+ * r5c journal modes of the array: write-back or write-through.
+ * write-through mode has identical behavior as existing log only
+ * implementation.
+ */
+enum r5c_journal_mode {
+ R5C_JOURNAL_MODE_WRITE_THROUGH = 0,
+ R5C_JOURNAL_MODE_WRITE_BACK = 1,
+};
+
+static char *r5c_journal_mode_str[] = {"write-through",
+ "write-back"};
+/*
+ * raid5 cache state machine
+ *
+ * With the RAID cache, each stripe works in two phases:
+ * - caching phase
+ * - writing-out phase
+ *
+ * These two phases are controlled by bit STRIPE_R5C_CACHING:
+ * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
+ * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
+ *
+ * When there is no journal, or the journal is in write-through mode,
+ * the stripe is always in writing-out phase.
+ *
+ * For write-back journal, the stripe is sent to caching phase on write
+ * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
+ * the write-out phase by clearing STRIPE_R5C_CACHING.
+ *
+ * Stripes in caching phase do not write the raid disks. Instead, all
+ * writes are committed from the log device. Therefore, a stripe in
+ * caching phase handles writes as:
+ * - write to log device
+ * - return IO
+ *
+ * Stripes in writing-out phase handle writes as:
+ * - calculate parity
+ * - write pending data and parity to journal
+ * - write data and parity to raid disks
+ * - return IO for pending writes
+ */
+
struct r5l_log {
struct md_rdev *rdev;
@@ -58,7 +113,6 @@ struct r5l_log {
u64 seq; /* log head sequence */
sector_t next_checkpoint;
- u64 next_cp_seq;
struct mutex io_mutex;
struct r5l_io_unit *current_io; /* current io_unit accepting new data */
@@ -96,6 +150,18 @@ struct r5l_log {
spinlock_t no_space_stripes_lock;
bool need_cache_flush;
+
+ /* for r5c_cache */
+ enum r5c_journal_mode r5c_journal_mode;
+
+ /* all stripes in r5cache, in the order of seq at sh->log_start */
+ struct list_head stripe_in_journal_list;
+
+ spinlock_t stripe_in_journal_lock;
+ atomic_t stripe_in_journal_count;
+
+ /* to submit async io_units, to fulfill ordering of flush */
+ struct work_struct deferred_io_work;
};
/*
@@ -122,6 +188,18 @@ struct r5l_io_unit {
int state;
bool need_split_bio;
+ struct bio *split_bio;
+
+ unsigned int has_flush:1; /* include flush request */
+ unsigned int has_fua:1; /* include fua request */
+ unsigned int has_null_flush:1; /* include empty flush request */
+ /*
+ * io isn't sent yet, flush/fua request can only be submitted till it's
+ * the first IO in running_ios list
+ */
+ unsigned int io_deferred:1;
+
+ struct bio_list flush_barriers; /* size == 0 flush bios */
};
/* r5l_io_unit state */
@@ -133,6 +211,12 @@ enum r5l_io_unit_state {
IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
};
+bool r5c_is_writeback(struct r5l_log *log)
+{
+ return (log != NULL &&
+ log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
+}
+
static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
{
start += inc;
@@ -168,12 +252,235 @@ static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
io->state = state;
}
+static void
+r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev,
+ struct bio_list *return_bi)
+{
+ struct bio *wbi, *wbi2;
+
+ wbi = dev->written;
+ dev->written = NULL;
+ while (wbi && wbi->bi_iter.bi_sector <
+ dev->sector + STRIPE_SECTORS) {
+ wbi2 = r5_next_bio(wbi, dev->sector);
+ if (!raid5_dec_bi_active_stripes(wbi)) {
+ md_write_end(conf->mddev);
+ bio_list_add(return_bi, wbi);
+ }
+ wbi = wbi2;
+ }
+}
+
+void r5c_handle_cached_data_endio(struct r5conf *conf,
+ struct stripe_head *sh, int disks, struct bio_list *return_bi)
+{
+ int i;
+
+ for (i = sh->disks; i--; ) {
+ if (sh->dev[i].written) {
+ set_bit(R5_UPTODATE, &sh->dev[i].flags);
+ r5c_return_dev_pending_writes(conf, &sh->dev[i],
+ return_bi);
+ bitmap_endwrite(conf->mddev->bitmap, sh->sector,
+ STRIPE_SECTORS,
+ !test_bit(STRIPE_DEGRADED, &sh->state),
+ 0);
+ }
+ }
+}
+
+/* Check whether we should flush some stripes to free up stripe cache */
+void r5c_check_stripe_cache_usage(struct r5conf *conf)
+{
+ int total_cached;
+
+ if (!r5c_is_writeback(conf->log))
+ return;
+
+ total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
+ atomic_read(&conf->r5c_cached_full_stripes);
+
+ /*
+ * The following condition is true for either of the following:
+ * - stripe cache pressure high:
+ * total_cached > 3/4 min_nr_stripes ||
+ * empty_inactive_list_nr > 0
+ * - stripe cache pressure moderate:
+ * total_cached > 1/2 min_nr_stripes
+ */
+ if (total_cached > conf->min_nr_stripes * 1 / 2 ||
+ atomic_read(&conf->empty_inactive_list_nr) > 0)
+ r5l_wake_reclaim(conf->log, 0);
+}
+
+/*
+ * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
+ * stripes in the cache
+ */
+void r5c_check_cached_full_stripe(struct r5conf *conf)
+{
+ if (!r5c_is_writeback(conf->log))
+ return;
+
+ /*
+ * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
+ * or a full stripe (chunk size / 4k stripes).
+ */
+ if (atomic_read(&conf->r5c_cached_full_stripes) >=
+ min(R5C_FULL_STRIPE_FLUSH_BATCH,
+ conf->chunk_sectors >> STRIPE_SHIFT))
+ r5l_wake_reclaim(conf->log, 0);
+}
+
+/*
+ * Total log space (in sectors) needed to flush all data in cache
+ *
+ * Currently, writing-out phase automatically includes all pending writes
+ * to the same sector. So the reclaim of each stripe takes up to
+ * (conf->raid_disks + 1) pages of log space.
+ *
+ * To totally avoid deadlock due to log space, the code reserves
+ * (conf->raid_disks + 1) pages for each stripe in cache, which is not
+ * necessary in most cases.
+ *
+ * To improve this, we will need writing-out phase to be able to NOT include
+ * pending writes, which will reduce the requirement to
+ * (conf->max_degraded + 1) pages per stripe in cache.
+ */
+static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
+{
+ struct r5l_log *log = conf->log;
+
+ if (!r5c_is_writeback(log))
+ return 0;
+
+ return BLOCK_SECTORS * (conf->raid_disks + 1) *
+ atomic_read(&log->stripe_in_journal_count);
+}
+
+/*
+ * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
+ *
+ * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
+ * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
+ * device is less than 2x of reclaim_required_space.
+ */
+static inline void r5c_update_log_state(struct r5l_log *log)
+{
+ struct r5conf *conf = log->rdev->mddev->private;
+ sector_t free_space;
+ sector_t reclaim_space;
+ bool wake_reclaim = false;
+
+ if (!r5c_is_writeback(log))
+ return;
+
+ free_space = r5l_ring_distance(log, log->log_start,
+ log->last_checkpoint);
+ reclaim_space = r5c_log_required_to_flush_cache(conf);
+ if (free_space < 2 * reclaim_space)
+ set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+ else {
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
+ wake_reclaim = true;
+ clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
+ }
+ if (free_space < 3 * reclaim_space)
+ set_bit(R5C_LOG_TIGHT, &conf->cache_state);
+ else
+ clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
+
+ if (wake_reclaim)
+ r5l_wake_reclaim(log, 0);
+}
+
+/*
+ * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
+ * This function should only be called in write-back mode.
+ */
+void r5c_make_stripe_write_out(struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+ struct r5l_log *log = conf->log;
+
+ BUG_ON(!r5c_is_writeback(log));
+
+ WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
+ clear_bit(STRIPE_R5C_CACHING, &sh->state);
+
+ if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ atomic_inc(&conf->preread_active_stripes);
+
+ if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
+ BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
+ atomic_dec(&conf->r5c_cached_partial_stripes);
+ }
+
+ if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
+ BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
+ atomic_dec(&conf->r5c_cached_full_stripes);
+ }
+}
+
+static void r5c_handle_data_cached(struct stripe_head *sh)
+{
+ int i;
+
+ for (i = sh->disks; i--; )
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ set_bit(R5_InJournal, &sh->dev[i].flags);
+ clear_bit(R5_LOCKED, &sh->dev[i].flags);
+ }
+ clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
+}
+
+/*
+ * this journal write must contain full parity,
+ * it may also contain some data pages
+ */
+static void r5c_handle_parity_cached(struct stripe_head *sh)
+{
+ int i;
+
+ for (i = sh->disks; i--; )
+ if (test_bit(R5_InJournal, &sh->dev[i].flags))
+ set_bit(R5_Wantwrite, &sh->dev[i].flags);
+}
+
+/*
+ * Setting proper flags after writing (or flushing) data and/or parity to the
+ * log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
+ */
+static void r5c_finish_cache_stripe(struct stripe_head *sh)
+{
+ struct r5l_log *log = sh->raid_conf->log;
+
+ if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
+ BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
+ /*
+ * Set R5_InJournal for parity dev[pd_idx]. This means
+ * all data AND parity in the journal. For RAID 6, it is
+ * NOT necessary to set the flag for dev[qd_idx], as the
+ * two parities are written out together.
+ */
+ set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
+ } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
+ r5c_handle_data_cached(sh);
+ } else {
+ r5c_handle_parity_cached(sh);
+ set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
+ }
+}
+
static void r5l_io_run_stripes(struct r5l_io_unit *io)
{
struct stripe_head *sh, *next;
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
+
+ r5c_finish_cache_stripe(sh);
+
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
@@ -209,9 +516,11 @@ static void r5l_move_to_end_ios(struct r5l_log *log)
}
}
+static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
static void r5l_log_endio(struct bio *bio)
{
struct r5l_io_unit *io = bio->bi_private;
+ struct r5l_io_unit *io_deferred;
struct r5l_log *log = io->log;
unsigned long flags;
@@ -227,18 +536,89 @@ static void r5l_log_endio(struct bio *bio)
r5l_move_to_end_ios(log);
else
r5l_log_run_stripes(log);
+ if (!list_empty(&log->running_ios)) {
+ /*
+ * FLUSH/FUA io_unit is deferred because of ordering, now we
+ * can dispatch it
+ */
+ io_deferred = list_first_entry(&log->running_ios,
+ struct r5l_io_unit, log_sibling);
+ if (io_deferred->io_deferred)
+ schedule_work(&log->deferred_io_work);
+ }
+
spin_unlock_irqrestore(&log->io_list_lock, flags);
if (log->need_cache_flush)
md_wakeup_thread(log->rdev->mddev->thread);
+
+ if (io->has_null_flush) {
+ struct bio *bi;
+
+ WARN_ON(bio_list_empty(&io->flush_barriers));
+ while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
+ bio_endio(bi);
+ atomic_dec(&io->pending_stripe);
+ }
+ if (atomic_read(&io->pending_stripe) == 0)
+ __r5l_stripe_write_finished(io);
+ }
+}
+
+static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&log->io_list_lock, flags);
+ __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
+
+ if (io->has_flush)
+ io->current_bio->bi_opf |= REQ_PREFLUSH;
+ if (io->has_fua)
+ io->current_bio->bi_opf |= REQ_FUA;
+ submit_bio(io->current_bio);
+
+ if (!io->split_bio)
+ return;
+
+ if (io->has_flush)
+ io->split_bio->bi_opf |= REQ_PREFLUSH;
+ if (io->has_fua)
+ io->split_bio->bi_opf |= REQ_FUA;
+ submit_bio(io->split_bio);
+}
+
+/* deferred io_unit will be dispatched here */
+static void r5l_submit_io_async(struct work_struct *work)
+{
+ struct r5l_log *log = container_of(work, struct r5l_log,
+ deferred_io_work);
+ struct r5l_io_unit *io = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&log->io_list_lock, flags);
+ if (!list_empty(&log->running_ios)) {
+ io = list_first_entry(&log->running_ios, struct r5l_io_unit,
+ log_sibling);
+ if (!io->io_deferred)
+ io = NULL;
+ else
+ io->io_deferred = 0;
+ }
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
+ if (io)
+ r5l_do_submit_io(log, io);
}
static void r5l_submit_current_io(struct r5l_log *log)
{
struct r5l_io_unit *io = log->current_io;
+ struct bio *bio;
struct r5l_meta_block *block;
unsigned long flags;
u32 crc;
+ bool do_submit = true;
if (!io)
return;
@@ -247,13 +627,20 @@ static void r5l_submit_current_io(struct r5l_log *log)
block->meta_size = cpu_to_le32(io->meta_offset);
crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
block->checksum = cpu_to_le32(crc);
+ bio = io->current_bio;
log->current_io = NULL;
spin_lock_irqsave(&log->io_list_lock, flags);
- __r5l_set_io_unit_state(io, IO_UNIT_IO_START);
+ if (io->has_flush || io->has_fua) {
+ if (io != list_first_entry(&log->running_ios,
+ struct r5l_io_unit, log_sibling)) {
+ io->io_deferred = 1;
+ do_submit = false;
+ }
+ }
spin_unlock_irqrestore(&log->io_list_lock, flags);
-
- submit_bio(io->current_bio);
+ if (do_submit)
+ r5l_do_submit_io(log, io);
}
static struct bio *r5l_bio_alloc(struct r5l_log *log)
@@ -271,6 +658,7 @@ static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
{
log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
+ r5c_update_log_state(log);
/*
* If we filled up the log device start from the beginning again,
* which will require a new bio.
@@ -297,6 +685,7 @@ static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
+ bio_list_init(&io->flush_barriers);
io->state = IO_UNIT_RUNNING;
io->meta_page = mempool_alloc(log->meta_pool, GFP_NOIO);
@@ -367,12 +756,11 @@ static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
struct r5l_io_unit *io = log->current_io;
if (io->need_split_bio) {
- struct bio *prev = io->current_bio;
-
+ BUG_ON(io->split_bio);
+ io->split_bio = io->current_bio;
io->current_bio = r5l_bio_alloc(log);
- bio_chain(io->current_bio, prev);
-
- submit_bio(prev);
+ bio_chain(io->current_bio, io->split_bio);
+ io->need_split_bio = false;
}
if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
@@ -401,50 +789,85 @@ static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
io = log->current_io;
+ if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
+ io->has_flush = 1;
+
for (i = 0; i < sh->disks; i++) {
- if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
+ if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
+ test_bit(R5_InJournal, &sh->dev[i].flags))
continue;
if (i == sh->pd_idx || i == sh->qd_idx)
continue;
+ if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
+ log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
+ io->has_fua = 1;
+ /*
+ * we need to flush journal to make sure recovery can
+ * reach the data with fua flag
+ */
+ io->has_flush = 1;
+ }
r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
raid5_compute_blocknr(sh, i, 0),
sh->dev[i].log_checksum, 0, false);
r5l_append_payload_page(log, sh->dev[i].page);
}
- if (sh->qd_idx >= 0) {
+ if (parity_pages == 2) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
sh->dev[sh->qd_idx].log_checksum, true);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
- } else {
+ } else if (parity_pages == 1) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
0, false);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
- }
+ } else /* Just writing data, not parity, in caching phase */
+ BUG_ON(parity_pages != 0);
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripe);
sh->log_io = io;
+ if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
+ return 0;
+
+ if (sh->log_start == MaxSector) {
+ BUG_ON(!list_empty(&sh->r5c));
+ sh->log_start = io->log_start;
+ spin_lock_irq(&log->stripe_in_journal_lock);
+ list_add_tail(&sh->r5c,
+ &log->stripe_in_journal_list);
+ spin_unlock_irq(&log->stripe_in_journal_lock);
+ atomic_inc(&log->stripe_in_journal_count);
+ }
return 0;
}
-static void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
+/* add stripe to no_space_stripes, and then wake up reclaim */
+static inline void r5l_add_no_space_stripe(struct r5l_log *log,
+ struct stripe_head *sh)
+{
+ spin_lock(&log->no_space_stripes_lock);
+ list_add_tail(&sh->log_list, &log->no_space_stripes);
+ spin_unlock(&log->no_space_stripes_lock);
+}
+
/*
* running in raid5d, where reclaim could wait for raid5d too (when it flushes
* data from log to raid disks), so we shouldn't wait for reclaim here
*/
int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
{
+ struct r5conf *conf = sh->raid_conf;
int write_disks = 0;
int data_pages, parity_pages;
- int meta_size;
int reserve;
int i;
int ret = 0;
+ bool wake_reclaim = false;
if (!log)
return -EAGAIN;
@@ -456,11 +879,15 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
return -EAGAIN;
}
+ WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
+
for (i = 0; i < sh->disks; i++) {
void *addr;
- if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
+ if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
+ test_bit(R5_InJournal, &sh->dev[i].flags))
continue;
+
write_disks++;
/* checksum is already calculated in last run */
if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
@@ -473,15 +900,6 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
parity_pages = 1 + !!(sh->qd_idx >= 0);
data_pages = write_disks - parity_pages;
- meta_size =
- ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
- * data_pages) +
- sizeof(struct r5l_payload_data_parity) +
- sizeof(__le32) * parity_pages;
- /* Doesn't work with very big raid array */
- if (meta_size + sizeof(struct r5l_meta_block) > PAGE_SIZE)
- return -EINVAL;
-
set_bit(STRIPE_LOG_TRAPPED, &sh->state);
/*
* The stripe must enter state machine again to finish the write, so
@@ -493,22 +911,49 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
- if (!r5l_has_free_space(log, reserve)) {
- spin_lock(&log->no_space_stripes_lock);
- list_add_tail(&sh->log_list, &log->no_space_stripes);
- spin_unlock(&log->no_space_stripes_lock);
- r5l_wake_reclaim(log, reserve);
- } else {
- ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
- if (ret) {
- spin_lock_irq(&log->io_list_lock);
- list_add_tail(&sh->log_list, &log->no_mem_stripes);
- spin_unlock_irq(&log->io_list_lock);
+ if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
+ if (!r5l_has_free_space(log, reserve)) {
+ r5l_add_no_space_stripe(log, sh);
+ wake_reclaim = true;
+ } else {
+ ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list,
+ &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
+ }
+ }
+ } else { /* R5C_JOURNAL_MODE_WRITE_BACK */
+ /*
+ * log space critical, do not process stripes that are
+ * not in cache yet (sh->log_start == MaxSector).
+ */
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
+ sh->log_start == MaxSector) {
+ r5l_add_no_space_stripe(log, sh);
+ wake_reclaim = true;
+ reserve = 0;
+ } else if (!r5l_has_free_space(log, reserve)) {
+ if (sh->log_start == log->last_checkpoint)
+ BUG();
+ else
+ r5l_add_no_space_stripe(log, sh);
+ } else {
+ ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list,
+ &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
+ }
}
}
mutex_unlock(&log->io_mutex);
+ if (wake_reclaim)
+ r5l_wake_reclaim(log, reserve);
return 0;
}
@@ -525,17 +970,34 @@ int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
{
if (!log)
return -ENODEV;
- /*
- * we flush log disk cache first, then write stripe data to raid disks.
- * So if bio is finished, the log disk cache is flushed already. The
- * recovery guarantees we can recovery the bio from log disk, so we
- * don't need to flush again
- */
- if (bio->bi_iter.bi_size == 0) {
- bio_endio(bio);
- return 0;
+
+ if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
+ /*
+ * in write through (journal only)
+ * we flush log disk cache first, then write stripe data to
+ * raid disks. So if bio is finished, the log disk cache is
+ * flushed already. The recovery guarantees we can recovery
+ * the bio from log disk, so we don't need to flush again
+ */
+ if (bio->bi_iter.bi_size == 0) {
+ bio_endio(bio);
+ return 0;
+ }
+ bio->bi_opf &= ~REQ_PREFLUSH;
+ } else {
+ /* write back (with cache) */
+ if (bio->bi_iter.bi_size == 0) {
+ mutex_lock(&log->io_mutex);
+ r5l_get_meta(log, 0);
+ bio_list_add(&log->current_io->flush_barriers, bio);
+ log->current_io->has_flush = 1;
+ log->current_io->has_null_flush = 1;
+ atomic_inc(&log->current_io->pending_stripe);
+ r5l_submit_current_io(log);
+ mutex_unlock(&log->io_mutex);
+ return 0;
+ }
}
- bio->bi_opf &= ~REQ_PREFLUSH;
return -EAGAIN;
}
@@ -555,10 +1017,40 @@ static void r5l_run_no_space_stripes(struct r5l_log *log)
spin_unlock(&log->no_space_stripes_lock);
}
+/*
+ * calculate new last_checkpoint
+ * for write through mode, returns log->next_checkpoint
+ * for write back, returns log_start of first sh in stripe_in_journal_list
+ */
+static sector_t r5c_calculate_new_cp(struct r5conf *conf)
+{
+ struct stripe_head *sh;
+ struct r5l_log *log = conf->log;
+ sector_t new_cp;
+ unsigned long flags;
+
+ if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
+ return log->next_checkpoint;
+
+ spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
+ if (list_empty(&conf->log->stripe_in_journal_list)) {
+ /* all stripes flushed */
+ spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
+ return log->next_checkpoint;
+ }
+ sh = list_first_entry(&conf->log->stripe_in_journal_list,
+ struct stripe_head, r5c);
+ new_cp = sh->log_start;
+ spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
+ return new_cp;
+}
+
static sector_t r5l_reclaimable_space(struct r5l_log *log)
{
+ struct r5conf *conf = log->rdev->mddev->private;
+
return r5l_ring_distance(log, log->last_checkpoint,
- log->next_checkpoint);
+ r5c_calculate_new_cp(conf));
}
static void r5l_run_no_mem_stripe(struct r5l_log *log)
@@ -589,7 +1081,6 @@ static bool r5l_complete_finished_ios(struct r5l_log *log)
break;
log->next_checkpoint = io->log_start;
- log->next_cp_seq = io->seq;
list_del(&io->log_sibling);
mempool_free(io, log->io_pool);
@@ -604,6 +1095,7 @@ static bool r5l_complete_finished_ios(struct r5l_log *log)
static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
{
struct r5l_log *log = io->log;
+ struct r5conf *conf = log->rdev->mddev->private;
unsigned long flags;
spin_lock_irqsave(&log->io_list_lock, flags);
@@ -614,7 +1106,8 @@ static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
return;
}
- if (r5l_reclaimable_space(log) > log->max_free_space)
+ if (r5l_reclaimable_space(log) > log->max_free_space ||
+ test_bit(R5C_LOG_TIGHT, &conf->cache_state))
r5l_wake_reclaim(log, 0);
spin_unlock_irqrestore(&log->io_list_lock, flags);
@@ -713,8 +1206,8 @@ static void r5l_write_super_and_discard_space(struct r5l_log *log,
* there is a deadlock. We workaround this issue with a trylock.
* FIXME: we could miss discard if we can't take reconfig mutex
*/
- set_mask_bits(&mddev->flags, 0,
- BIT(MD_CHANGE_DEVS) | BIT(MD_CHANGE_PENDING));
+ set_mask_bits(&mddev->sb_flags, 0,
+ BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
if (!mddev_trylock(mddev))
return;
md_update_sb(mddev, 1);
@@ -735,15 +1228,148 @@ static void r5l_write_super_and_discard_space(struct r5l_log *log,
}
}
+/*
+ * r5c_flush_stripe moves stripe from cached list to handle_list. When called,
+ * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
+ *
+ * must hold conf->device_lock
+ */
+static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
+{
+ BUG_ON(list_empty(&sh->lru));
+ BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
+ BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
+
+ /*
+ * The stripe is not ON_RELEASE_LIST, so it is safe to call
+ * raid5_release_stripe() while holding conf->device_lock
+ */
+ BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
+ assert_spin_locked(&conf->device_lock);
+
+ list_del_init(&sh->lru);
+ atomic_inc(&sh->count);
+
+ set_bit(STRIPE_HANDLE, &sh->state);
+ atomic_inc(&conf->active_stripes);
+ r5c_make_stripe_write_out(sh);
+
+ raid5_release_stripe(sh);
+}
+
+/*
+ * if num == 0, flush all full stripes
+ * if num > 0, flush all full stripes. If less than num full stripes are
+ * flushed, flush some partial stripes until totally num stripes are
+ * flushed or there is no more cached stripes.
+ */
+void r5c_flush_cache(struct r5conf *conf, int num)
+{
+ int count;
+ struct stripe_head *sh, *next;
+
+ assert_spin_locked(&conf->device_lock);
+ if (!conf->log)
+ return;
+
+ count = 0;
+ list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
+ r5c_flush_stripe(conf, sh);
+ count++;
+ }
+
+ if (count >= num)
+ return;
+ list_for_each_entry_safe(sh, next,
+ &conf->r5c_partial_stripe_list, lru) {
+ r5c_flush_stripe(conf, sh);
+ if (++count >= num)
+ break;
+ }
+}
+
+static void r5c_do_reclaim(struct r5conf *conf)
+{
+ struct r5l_log *log = conf->log;
+ struct stripe_head *sh;
+ int count = 0;
+ unsigned long flags;
+ int total_cached;
+ int stripes_to_flush;
+
+ if (!r5c_is_writeback(log))
+ return;
+
+ total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
+ atomic_read(&conf->r5c_cached_full_stripes);
+
+ if (total_cached > conf->min_nr_stripes * 3 / 4 ||
+ atomic_read(&conf->empty_inactive_list_nr) > 0)
+ /*
+ * if stripe cache pressure high, flush all full stripes and
+ * some partial stripes
+ */
+ stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
+ else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
+ atomic_read(&conf->r5c_cached_full_stripes) >
+ R5C_FULL_STRIPE_FLUSH_BATCH)
+ /*
+ * if stripe cache pressure moderate, or if there is many full
+ * stripes,flush all full stripes
+ */
+ stripes_to_flush = 0;
+ else
+ /* no need to flush */
+ stripes_to_flush = -1;
+
+ if (stripes_to_flush >= 0) {
+ spin_lock_irqsave(&conf->device_lock, flags);
+ r5c_flush_cache(conf, stripes_to_flush);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ /* if log space is tight, flush stripes on stripe_in_journal_list */
+ if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
+ spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
+ spin_lock(&conf->device_lock);
+ list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
+ /*
+ * stripes on stripe_in_journal_list could be in any
+ * state of the stripe_cache state machine. In this
+ * case, we only want to flush stripe on
+ * r5c_cached_full/partial_stripes. The following
+ * condition makes sure the stripe is on one of the
+ * two lists.
+ */
+ if (!list_empty(&sh->lru) &&
+ !test_bit(STRIPE_HANDLE, &sh->state) &&
+ atomic_read(&sh->count) == 0) {
+ r5c_flush_stripe(conf, sh);
+ }
+ if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
+ break;
+ }
+ spin_unlock(&conf->device_lock);
+ spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
+ }
+
+ if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
+ r5l_run_no_space_stripes(log);
+
+ md_wakeup_thread(conf->mddev->thread);
+}
static void r5l_do_reclaim(struct r5l_log *log)
{
+ struct r5conf *conf = log->rdev->mddev->private;
sector_t reclaim_target = xchg(&log->reclaim_target, 0);
sector_t reclaimable;
sector_t next_checkpoint;
- u64 next_cp_seq;
+ bool write_super;
spin_lock_irq(&log->io_list_lock);
+ write_super = r5l_reclaimable_space(log) > log->max_free_space ||
+ reclaim_target != 0 || !list_empty(&log->no_space_stripes);
/*
* move proper io_unit to reclaim list. We should not change the order.
* reclaimable/unreclaimable io_unit can be mixed in the list, we
@@ -764,12 +1390,12 @@ static void r5l_do_reclaim(struct r5l_log *log)
log->io_list_lock);
}
- next_checkpoint = log->next_checkpoint;
- next_cp_seq = log->next_cp_seq;
+ next_checkpoint = r5c_calculate_new_cp(conf);
spin_unlock_irq(&log->io_list_lock);
BUG_ON(reclaimable < 0);
- if (reclaimable == 0)
+
+ if (reclaimable == 0 || !write_super)
return;
/*
@@ -781,7 +1407,7 @@ static void r5l_do_reclaim(struct r5l_log *log)
mutex_lock(&log->io_mutex);
log->last_checkpoint = next_checkpoint;
- log->last_cp_seq = next_cp_seq;
+ r5c_update_log_state(log);
mutex_unlock(&log->io_mutex);
r5l_run_no_space_stripes(log);
@@ -795,14 +1421,17 @@ static void r5l_reclaim_thread(struct md_thread *thread)
if (!log)
return;
+ r5c_do_reclaim(conf);
r5l_do_reclaim(log);
}
-static void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
+void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
{
unsigned long target;
unsigned long new = (unsigned long)space; /* overflow in theory */
+ if (!log)
+ return;
do {
target = log->reclaim_target;
if (new < target)
@@ -816,22 +1445,14 @@ void r5l_quiesce(struct r5l_log *log, int state)
struct mddev *mddev;
if (!log || state == 2)
return;
- if (state == 0) {
- /*
- * This is a special case for hotadd. In suspend, the array has
- * no journal. In resume, journal is initialized as well as the
- * reclaim thread.
- */
- if (log->reclaim_thread)
- return;
- log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
- log->rdev->mddev, "reclaim");
- } else if (state == 1) {
+ if (state == 0)
+ kthread_unpark(log->reclaim_thread->tsk);
+ else if (state == 1) {
/* make sure r5l_write_super_and_discard_space exits */
mddev = log->rdev->mddev;
wake_up(&mddev->sb_wait);
- r5l_wake_reclaim(log, -1L);
- md_unregister_thread(&log->reclaim_thread);
+ kthread_park(log->reclaim_thread->tsk);
+ r5l_wake_reclaim(log, MaxSector);
r5l_do_reclaim(log);
}
}
@@ -857,10 +1478,13 @@ struct r5l_recovery_ctx {
sector_t meta_total_blocks; /* total size of current meta and data */
sector_t pos; /* recovery position */
u64 seq; /* recovery position seq */
+ int data_parity_stripes; /* number of data_parity stripes */
+ int data_only_stripes; /* number of data_only stripes */
+ struct list_head cached_list;
};
-static int r5l_read_meta_block(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx)
+static int r5l_recovery_read_meta_block(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
{
struct page *page = ctx->meta_page;
struct r5l_meta_block *mb;
@@ -892,170 +1516,618 @@ static int r5l_read_meta_block(struct r5l_log *log,
return 0;
}
-static int r5l_recovery_flush_one_stripe(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx,
- sector_t stripe_sect,
- int *offset, sector_t *log_offset)
+static void
+r5l_recovery_create_empty_meta_block(struct r5l_log *log,
+ struct page *page,
+ sector_t pos, u64 seq)
{
- struct r5conf *conf = log->rdev->mddev->private;
- struct stripe_head *sh;
- struct r5l_payload_data_parity *payload;
- int disk_index;
+ struct r5l_meta_block *mb;
- sh = raid5_get_active_stripe(conf, stripe_sect, 0, 0, 0);
- while (1) {
- payload = page_address(ctx->meta_page) + *offset;
+ mb = page_address(page);
+ clear_page(mb);
+ mb->magic = cpu_to_le32(R5LOG_MAGIC);
+ mb->version = R5LOG_VERSION;
+ mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
+ mb->seq = cpu_to_le64(seq);
+ mb->position = cpu_to_le64(pos);
+}
- if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
- raid5_compute_sector(conf,
- le64_to_cpu(payload->location), 0,
- &disk_index, sh);
+static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
+ u64 seq)
+{
+ struct page *page;
+ struct r5l_meta_block *mb;
- sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
- sh->dev[disk_index].page, REQ_OP_READ, 0,
- false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[0]);
- set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
- ctx->meta_total_blocks += BLOCK_SECTORS;
- } else {
- disk_index = sh->pd_idx;
- sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
- sh->dev[disk_index].page, REQ_OP_READ, 0,
- false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[0]);
- set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
-
- if (sh->qd_idx >= 0) {
- disk_index = sh->qd_idx;
- sync_page_io(log->rdev,
- r5l_ring_add(log, *log_offset, BLOCK_SECTORS),
- PAGE_SIZE, sh->dev[disk_index].page,
- REQ_OP_READ, 0, false);
- sh->dev[disk_index].log_checksum =
- le32_to_cpu(payload->checksum[1]);
- set_bit(R5_Wantwrite,
- &sh->dev[disk_index].flags);
- }
- ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
- }
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+ r5l_recovery_create_empty_meta_block(log, page, pos, seq);
+ mb = page_address(page);
+ mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
+ mb, PAGE_SIZE));
+ if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
+ REQ_FUA, false)) {
+ __free_page(page);
+ return -EIO;
+ }
+ __free_page(page);
+ return 0;
+}
- *log_offset = r5l_ring_add(log, *log_offset,
- le32_to_cpu(payload->size));
- *offset += sizeof(struct r5l_payload_data_parity) +
- sizeof(__le32) *
- (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
- if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
- break;
+/*
+ * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
+ * to mark valid (potentially not flushed) data in the journal.
+ *
+ * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
+ * so there should not be any mismatch here.
+ */
+static void r5l_recovery_load_data(struct r5l_log *log,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx,
+ struct r5l_payload_data_parity *payload,
+ sector_t log_offset)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
+ int dd_idx;
+
+ raid5_compute_sector(conf,
+ le64_to_cpu(payload->location), 0,
+ &dd_idx, sh);
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ sh->dev[dd_idx].page, REQ_OP_READ, 0, false);
+ sh->dev[dd_idx].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ ctx->meta_total_blocks += BLOCK_SECTORS;
+
+ set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
+ set_bit(STRIPE_R5C_CACHING, &sh->state);
+}
+
+static void r5l_recovery_load_parity(struct r5l_log *log,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx,
+ struct r5l_payload_data_parity *payload,
+ sector_t log_offset)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
+
+ ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ sh->dev[sh->pd_idx].page, REQ_OP_READ, 0, false);
+ sh->dev[sh->pd_idx].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
+
+ if (sh->qd_idx >= 0) {
+ sync_page_io(log->rdev,
+ r5l_ring_add(log, log_offset, BLOCK_SECTORS),
+ PAGE_SIZE, sh->dev[sh->qd_idx].page,
+ REQ_OP_READ, 0, false);
+ sh->dev[sh->qd_idx].log_checksum =
+ le32_to_cpu(payload->checksum[1]);
+ set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
}
+ clear_bit(STRIPE_R5C_CACHING, &sh->state);
+}
- for (disk_index = 0; disk_index < sh->disks; disk_index++) {
- void *addr;
- u32 checksum;
+static void r5l_recovery_reset_stripe(struct stripe_head *sh)
+{
+ int i;
+ sh->state = 0;
+ sh->log_start = MaxSector;
+ for (i = sh->disks; i--; )
+ sh->dev[i].flags = 0;
+}
+
+static void
+r5l_recovery_replay_one_stripe(struct r5conf *conf,
+ struct stripe_head *sh,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct md_rdev *rdev, *rrdev;
+ int disk_index;
+ int data_count = 0;
+
+ for (disk_index = 0; disk_index < sh->disks; disk_index++) {
if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
- addr = kmap_atomic(sh->dev[disk_index].page);
- checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
- kunmap_atomic(addr);
- if (checksum != sh->dev[disk_index].log_checksum)
- goto error;
+ if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
+ continue;
+ data_count++;
}
- for (disk_index = 0; disk_index < sh->disks; disk_index++) {
- struct md_rdev *rdev, *rrdev;
+ /*
+ * stripes that only have parity must have been flushed
+ * before the crash that we are now recovering from, so
+ * there is nothing more to recovery.
+ */
+ if (data_count == 0)
+ goto out;
- if (!test_and_clear_bit(R5_Wantwrite,
- &sh->dev[disk_index].flags))
+ for (disk_index = 0; disk_index < sh->disks; disk_index++) {
+ if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
/* in case device is broken */
+ rcu_read_lock();
rdev = rcu_dereference(conf->disks[disk_index].rdev);
- if (rdev)
- sync_page_io(rdev, stripe_sect, PAGE_SIZE,
+ if (rdev) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ sync_page_io(rdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE, 0,
false);
+ rdev_dec_pending(rdev, rdev->mddev);
+ rcu_read_lock();
+ }
rrdev = rcu_dereference(conf->disks[disk_index].replacement);
- if (rrdev)
- sync_page_io(rrdev, stripe_sect, PAGE_SIZE,
+ if (rrdev) {
+ atomic_inc(&rrdev->nr_pending);
+ rcu_read_unlock();
+ sync_page_io(rrdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE, 0,
false);
+ rdev_dec_pending(rrdev, rrdev->mddev);
+ rcu_read_lock();
+ }
+ rcu_read_unlock();
}
- raid5_release_stripe(sh);
+ ctx->data_parity_stripes++;
+out:
+ r5l_recovery_reset_stripe(sh);
+}
+
+static struct stripe_head *
+r5c_recovery_alloc_stripe(struct r5conf *conf,
+ sector_t stripe_sect,
+ sector_t log_start)
+{
+ struct stripe_head *sh;
+
+ sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0);
+ if (!sh)
+ return NULL; /* no more stripe available */
+
+ r5l_recovery_reset_stripe(sh);
+ sh->log_start = log_start;
+
+ return sh;
+}
+
+static struct stripe_head *
+r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
+{
+ struct stripe_head *sh;
+
+ list_for_each_entry(sh, list, lru)
+ if (sh->sector == sect)
+ return sh;
+ return NULL;
+}
+
+static void
+r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct stripe_head *sh, *next;
+
+ list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
+ r5l_recovery_reset_stripe(sh);
+ list_del_init(&sh->lru);
+ raid5_release_stripe(sh);
+ }
+}
+
+static void
+r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct stripe_head *sh, *next;
+
+ list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
+ if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
+ r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
+ list_del_init(&sh->lru);
+ raid5_release_stripe(sh);
+ }
+}
+
+/* if matches return 0; otherwise return -EINVAL */
+static int
+r5l_recovery_verify_data_checksum(struct r5l_log *log, struct page *page,
+ sector_t log_offset, __le32 log_checksum)
+{
+ void *addr;
+ u32 checksum;
+
+ sync_page_io(log->rdev, log_offset, PAGE_SIZE,
+ page, REQ_OP_READ, 0, false);
+ addr = kmap_atomic(page);
+ checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
+}
+
+/*
+ * before loading data to stripe cache, we need verify checksum for all data,
+ * if there is mismatch for any data page, we drop all data in the mata block
+ */
+static int
+r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
+ struct r5l_meta_block *mb = page_address(ctx->meta_page);
+ sector_t mb_offset = sizeof(struct r5l_meta_block);
+ sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
+ struct page *page;
+ struct r5l_payload_data_parity *payload;
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ while (mb_offset < le32_to_cpu(mb->meta_size)) {
+ payload = (void *)mb + mb_offset;
+
+ if (payload->header.type == R5LOG_PAYLOAD_DATA) {
+ if (r5l_recovery_verify_data_checksum(
+ log, page, log_offset,
+ payload->checksum[0]) < 0)
+ goto mismatch;
+ } else if (payload->header.type == R5LOG_PAYLOAD_PARITY) {
+ if (r5l_recovery_verify_data_checksum(
+ log, page, log_offset,
+ payload->checksum[0]) < 0)
+ goto mismatch;
+ if (conf->max_degraded == 2 && /* q for RAID 6 */
+ r5l_recovery_verify_data_checksum(
+ log, page,
+ r5l_ring_add(log, log_offset,
+ BLOCK_SECTORS),
+ payload->checksum[1]) < 0)
+ goto mismatch;
+ } else /* not R5LOG_PAYLOAD_DATA or R5LOG_PAYLOAD_PARITY */
+ goto mismatch;
+
+ log_offset = r5l_ring_add(log, log_offset,
+ le32_to_cpu(payload->size));
+
+ mb_offset += sizeof(struct r5l_payload_data_parity) +
+ sizeof(__le32) *
+ (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
+ }
+
+ put_page(page);
return 0;
-error:
- for (disk_index = 0; disk_index < sh->disks; disk_index++)
- sh->dev[disk_index].flags = 0;
- raid5_release_stripe(sh);
+mismatch:
+ put_page(page);
return -EINVAL;
}
-static int r5l_recovery_flush_one_meta(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx)
+/*
+ * Analyze all data/parity pages in one meta block
+ * Returns:
+ * 0 for success
+ * -EINVAL for unknown playload type
+ * -EAGAIN for checksum mismatch of data page
+ * -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
+ */
+static int
+r5c_recovery_analyze_meta_block(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx,
+ struct list_head *cached_stripe_list)
{
- struct r5conf *conf = log->rdev->mddev->private;
- struct r5l_payload_data_parity *payload;
+ struct mddev *mddev = log->rdev->mddev;
+ struct r5conf *conf = mddev->private;
struct r5l_meta_block *mb;
- int offset;
+ struct r5l_payload_data_parity *payload;
+ int mb_offset;
sector_t log_offset;
- sector_t stripe_sector;
+ sector_t stripe_sect;
+ struct stripe_head *sh;
+ int ret;
+
+ /*
+ * for mismatch in data blocks, we will drop all data in this mb, but
+ * we will still read next mb for other data with FLUSH flag, as
+ * io_unit could finish out of order.
+ */
+ ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
+ if (ret == -EINVAL)
+ return -EAGAIN;
+ else if (ret)
+ return ret; /* -ENOMEM duo to alloc_page() failed */
mb = page_address(ctx->meta_page);
- offset = sizeof(struct r5l_meta_block);
+ mb_offset = sizeof(struct r5l_meta_block);
log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
- while (offset < le32_to_cpu(mb->meta_size)) {
+ while (mb_offset < le32_to_cpu(mb->meta_size)) {
int dd;
- payload = (void *)mb + offset;
- stripe_sector = raid5_compute_sector(conf,
- le64_to_cpu(payload->location), 0, &dd, NULL);
- if (r5l_recovery_flush_one_stripe(log, ctx, stripe_sector,
- &offset, &log_offset))
+ payload = (void *)mb + mb_offset;
+ stripe_sect = (payload->header.type == R5LOG_PAYLOAD_DATA) ?
+ raid5_compute_sector(
+ conf, le64_to_cpu(payload->location), 0, &dd,
+ NULL)
+ : le64_to_cpu(payload->location);
+
+ sh = r5c_recovery_lookup_stripe(cached_stripe_list,
+ stripe_sect);
+
+ if (!sh) {
+ sh = r5c_recovery_alloc_stripe(conf, stripe_sect, ctx->pos);
+ /*
+ * cannot get stripe from raid5_get_active_stripe
+ * try replay some stripes
+ */
+ if (!sh) {
+ r5c_recovery_replay_stripes(
+ cached_stripe_list, ctx);
+ sh = r5c_recovery_alloc_stripe(
+ conf, stripe_sect, ctx->pos);
+ }
+ if (!sh) {
+ pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
+ mdname(mddev),
+ conf->min_nr_stripes * 2);
+ raid5_set_cache_size(mddev,
+ conf->min_nr_stripes * 2);
+ sh = r5c_recovery_alloc_stripe(
+ conf, stripe_sect, ctx->pos);
+ }
+ if (!sh) {
+ pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
+ mdname(mddev));
+ return -ENOMEM;
+ }
+ list_add_tail(&sh->lru, cached_stripe_list);
+ }
+
+ if (payload->header.type == R5LOG_PAYLOAD_DATA) {
+ if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
+ test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
+ r5l_recovery_replay_one_stripe(conf, sh, ctx);
+ sh->log_start = ctx->pos;
+ list_move_tail(&sh->lru, cached_stripe_list);
+ }
+ r5l_recovery_load_data(log, sh, ctx, payload,
+ log_offset);
+ } else if (payload->header.type == R5LOG_PAYLOAD_PARITY)
+ r5l_recovery_load_parity(log, sh, ctx, payload,
+ log_offset);
+ else
return -EINVAL;
+
+ log_offset = r5l_ring_add(log, log_offset,
+ le32_to_cpu(payload->size));
+
+ mb_offset += sizeof(struct r5l_payload_data_parity) +
+ sizeof(__le32) *
+ (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
}
+
return 0;
}
-/* copy data/parity from log to raid disks */
-static void r5l_recovery_flush_log(struct r5l_log *log,
- struct r5l_recovery_ctx *ctx)
+/*
+ * Load the stripe into cache. The stripe will be written out later by
+ * the stripe cache state machine.
+ */
+static void r5c_recovery_load_one_stripe(struct r5l_log *log,
+ struct stripe_head *sh)
{
+ struct r5dev *dev;
+ int i;
+
+ for (i = sh->disks; i--; ) {
+ dev = sh->dev + i;
+ if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
+ set_bit(R5_InJournal, &dev->flags);
+ set_bit(R5_UPTODATE, &dev->flags);
+ }
+ }
+ list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
+ atomic_inc(&log->stripe_in_journal_count);
+}
+
+/*
+ * Scan through the log for all to-be-flushed data
+ *
+ * For stripes with data and parity, namely Data-Parity stripe
+ * (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
+ *
+ * For stripes with only data, namely Data-Only stripe
+ * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
+ *
+ * For a stripe, if we see data after parity, we should discard all previous
+ * data and parity for this stripe, as these data are already flushed to
+ * the array.
+ *
+ * At the end of the scan, we return the new journal_tail, which points to
+ * first data-only stripe on the journal device, or next invalid meta block.
+ */
+static int r5c_recovery_flush_log(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct stripe_head *sh;
+ int ret = 0;
+
+ /* scan through the log */
while (1) {
- if (r5l_read_meta_block(log, ctx))
- return;
- if (r5l_recovery_flush_one_meta(log, ctx))
- return;
+ if (r5l_recovery_read_meta_block(log, ctx))
+ break;
+
+ ret = r5c_recovery_analyze_meta_block(log, ctx,
+ &ctx->cached_list);
+ /*
+ * -EAGAIN means mismatch in data block, in this case, we still
+ * try scan the next metablock
+ */
+ if (ret && ret != -EAGAIN)
+ break; /* ret == -EINVAL or -ENOMEM */
ctx->seq++;
ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
}
+
+ if (ret == -ENOMEM) {
+ r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
+ return ret;
+ }
+
+ /* replay data-parity stripes */
+ r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
+
+ /* load data-only stripes to stripe cache */
+ list_for_each_entry(sh, &ctx->cached_list, lru) {
+ WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
+ r5c_recovery_load_one_stripe(log, sh);
+ ctx->data_only_stripes++;
+ }
+
+ return 0;
}
-static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
- u64 seq)
+/*
+ * we did a recovery. Now ctx.pos points to an invalid meta block. New
+ * log will start here. but we can't let superblock point to last valid
+ * meta block. The log might looks like:
+ * | meta 1| meta 2| meta 3|
+ * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
+ * superblock points to meta 1, we write a new valid meta 2n. if crash
+ * happens again, new recovery will start from meta 1. Since meta 2n is
+ * valid now, recovery will think meta 3 is valid, which is wrong.
+ * The solution is we create a new meta in meta2 with its seq == meta
+ * 1's seq + 10000 and let superblock points to meta2. The same recovery
+ * will not think meta 3 is a valid meta, because its seq doesn't match
+ */
+
+/*
+ * Before recovery, the log looks like the following
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^
+ * |- log->last_checkpoint
+ * |- log->last_cp_seq
+ *
+ * Now we scan through the log until we see invalid entry
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos
+ * |- log->last_cp_seq |- ctx->seq
+ *
+ * From this point, we need to increase seq number by 10 to avoid
+ * confusing next recovery.
+ *
+ * ---------------------------------------------
+ * | valid log | invalid log |
+ * ---------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+1
+ * |- log->last_cp_seq |- ctx->seq+10001
+ *
+ * However, it is not safe to start the state machine yet, because data only
+ * parities are not yet secured in RAID. To save these data only parities, we
+ * rewrite them from seq+11.
+ *
+ * -----------------------------------------------------------------
+ * | valid log | data only stripes | invalid log |
+ * -----------------------------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+n
+ * |- log->last_cp_seq |- ctx->seq+10000+n
+ *
+ * If failure happens again during this process, the recovery can safe start
+ * again from log->last_checkpoint.
+ *
+ * Once data only stripes are rewritten to journal, we move log_tail
+ *
+ * -----------------------------------------------------------------
+ * | old log | data only stripes | invalid log |
+ * -----------------------------------------------------------------
+ * ^ ^
+ * |- log->last_checkpoint |- ctx->pos+n
+ * |- log->last_cp_seq |- ctx->seq+10000+n
+ *
+ * Then we can safely start the state machine. If failure happens from this
+ * point on, the recovery will start from new log->last_checkpoint.
+ */
+static int
+r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
{
+ struct stripe_head *sh, *next;
+ struct mddev *mddev = log->rdev->mddev;
struct page *page;
- struct r5l_meta_block *mb;
- u32 crc;
- page = alloc_page(GFP_KERNEL | __GFP_ZERO);
- if (!page)
+ page = alloc_page(GFP_KERNEL);
+ if (!page) {
+ pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
+ mdname(mddev));
return -ENOMEM;
- mb = page_address(page);
- mb->magic = cpu_to_le32(R5LOG_MAGIC);
- mb->version = R5LOG_VERSION;
- mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
- mb->seq = cpu_to_le64(seq);
- mb->position = cpu_to_le64(pos);
- crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
- mb->checksum = cpu_to_le32(crc);
+ }
- if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
- REQ_FUA, false)) {
- __free_page(page);
- return -EIO;
+ list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
+ struct r5l_meta_block *mb;
+ int i;
+ int offset;
+ sector_t write_pos;
+
+ WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
+ r5l_recovery_create_empty_meta_block(log, page,
+ ctx->pos, ctx->seq);
+ mb = page_address(page);
+ offset = le32_to_cpu(mb->meta_size);
+ write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
+
+ for (i = sh->disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+ struct r5l_payload_data_parity *payload;
+ void *addr;
+
+ if (test_bit(R5_InJournal, &dev->flags)) {
+ payload = (void *)mb + offset;
+ payload->header.type = cpu_to_le16(
+ R5LOG_PAYLOAD_DATA);
+ payload->size = BLOCK_SECTORS;
+ payload->location = cpu_to_le64(
+ raid5_compute_blocknr(sh, i, 0));
+ addr = kmap_atomic(dev->page);
+ payload->checksum[0] = cpu_to_le32(
+ crc32c_le(log->uuid_checksum, addr,
+ PAGE_SIZE));
+ kunmap_atomic(addr);
+ sync_page_io(log->rdev, write_pos, PAGE_SIZE,
+ dev->page, REQ_OP_WRITE, 0, false);
+ write_pos = r5l_ring_add(log, write_pos,
+ BLOCK_SECTORS);
+ offset += sizeof(__le32) +
+ sizeof(struct r5l_payload_data_parity);
+
+ }
+ }
+ mb->meta_size = cpu_to_le32(offset);
+ mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
+ mb, PAGE_SIZE));
+ sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
+ REQ_OP_WRITE, REQ_FUA, false);
+ sh->log_start = ctx->pos;
+ ctx->pos = write_pos;
+ ctx->seq += 1;
+
+ list_del_init(&sh->lru);
+ raid5_release_stripe(sh);
}
__free_page(page);
return 0;
@@ -1063,45 +2135,60 @@ static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
static int r5l_recovery_log(struct r5l_log *log)
{
+ struct mddev *mddev = log->rdev->mddev;
struct r5l_recovery_ctx ctx;
+ int ret;
+ sector_t pos;
+ struct stripe_head *sh;
ctx.pos = log->last_checkpoint;
ctx.seq = log->last_cp_seq;
ctx.meta_page = alloc_page(GFP_KERNEL);
+ ctx.data_only_stripes = 0;
+ ctx.data_parity_stripes = 0;
+ INIT_LIST_HEAD(&ctx.cached_list);
+
if (!ctx.meta_page)
return -ENOMEM;
- r5l_recovery_flush_log(log, &ctx);
+ ret = r5c_recovery_flush_log(log, &ctx);
__free_page(ctx.meta_page);
- /*
- * we did a recovery. Now ctx.pos points to an invalid meta block. New
- * log will start here. but we can't let superblock point to last valid
- * meta block. The log might looks like:
- * | meta 1| meta 2| meta 3|
- * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
- * superblock points to meta 1, we write a new valid meta 2n. if crash
- * happens again, new recovery will start from meta 1. Since meta 2n is
- * valid now, recovery will think meta 3 is valid, which is wrong.
- * The solution is we create a new meta in meta2 with its seq == meta
- * 1's seq + 10 and let superblock points to meta2. The same recovery will
- * not think meta 3 is a valid meta, because its seq doesn't match
- */
- if (ctx.seq > log->last_cp_seq) {
- int ret;
-
- ret = r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq + 10);
- if (ret)
- return ret;
- log->seq = ctx.seq + 11;
- log->log_start = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
- r5l_write_super(log, ctx.pos);
- log->last_checkpoint = ctx.pos;
+ if (ret)
+ return ret;
+
+ pos = ctx.pos;
+ ctx.seq += 10000;
+
+ if (ctx.data_only_stripes == 0) {
log->next_checkpoint = ctx.pos;
+ r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq++);
+ ctx.pos = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
} else {
- log->log_start = ctx.pos;
- log->seq = ctx.seq;
+ sh = list_last_entry(&ctx.cached_list, struct stripe_head, lru);
+ log->next_checkpoint = sh->log_start;
}
+
+ if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0))
+ pr_debug("md/raid:%s: starting from clean shutdown\n",
+ mdname(mddev));
+ else {
+ pr_debug("md/raid:%s: recoverying %d data-only stripes and %d data-parity stripes\n",
+ mdname(mddev), ctx.data_only_stripes,
+ ctx.data_parity_stripes);
+
+ if (ctx.data_only_stripes > 0)
+ if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
+ pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
+ mdname(mddev));
+ return -EIO;
+ }
+ }
+
+ log->log_start = ctx.pos;
+ log->seq = ctx.seq;
+ log->last_checkpoint = pos;
+ r5l_write_super(log, pos);
return 0;
}
@@ -1110,7 +2197,293 @@ static void r5l_write_super(struct r5l_log *log, sector_t cp)
struct mddev *mddev = log->rdev->mddev;
log->rdev->journal_tail = cp;
- set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
+}
+
+static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
+{
+ struct r5conf *conf = mddev->private;
+ int ret;
+
+ if (!conf->log)
+ return 0;
+
+ switch (conf->log->r5c_journal_mode) {
+ case R5C_JOURNAL_MODE_WRITE_THROUGH:
+ ret = snprintf(
+ page, PAGE_SIZE, "[%s] %s\n",
+ r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
+ r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
+ break;
+ case R5C_JOURNAL_MODE_WRITE_BACK:
+ ret = snprintf(
+ page, PAGE_SIZE, "%s [%s]\n",
+ r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
+ r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
+ break;
+ default:
+ ret = 0;
+ }
+ return ret;
+}
+
+static ssize_t r5c_journal_mode_store(struct mddev *mddev,
+ const char *page, size_t length)
+{
+ struct r5conf *conf = mddev->private;
+ struct r5l_log *log = conf->log;
+ int val = -1, i;
+ int len = length;
+
+ if (!log)
+ return -ENODEV;
+
+ if (len && page[len - 1] == '\n')
+ len -= 1;
+ for (i = 0; i < ARRAY_SIZE(r5c_journal_mode_str); i++)
+ if (strlen(r5c_journal_mode_str[i]) == len &&
+ strncmp(page, r5c_journal_mode_str[i], len) == 0) {
+ val = i;
+ break;
+ }
+ if (val < R5C_JOURNAL_MODE_WRITE_THROUGH ||
+ val > R5C_JOURNAL_MODE_WRITE_BACK)
+ return -EINVAL;
+
+ mddev_suspend(mddev);
+ conf->log->r5c_journal_mode = val;
+ mddev_resume(mddev);
+
+ pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
+ mdname(mddev), val, r5c_journal_mode_str[val]);
+ return length;
+}
+
+struct md_sysfs_entry
+r5c_journal_mode = __ATTR(journal_mode, 0644,
+ r5c_journal_mode_show, r5c_journal_mode_store);
+
+/*
+ * Try handle write operation in caching phase. This function should only
+ * be called in write-back mode.
+ *
+ * If all outstanding writes can be handled in caching phase, returns 0
+ * If writes requires write-out phase, call r5c_make_stripe_write_out()
+ * and returns -EAGAIN
+ */
+int r5c_try_caching_write(struct r5conf *conf,
+ struct stripe_head *sh,
+ struct stripe_head_state *s,
+ int disks)
+{
+ struct r5l_log *log = conf->log;
+ int i;
+ struct r5dev *dev;
+ int to_cache = 0;
+
+ BUG_ON(!r5c_is_writeback(log));
+
+ if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
+ /*
+ * There are two different scenarios here:
+ * 1. The stripe has some data cached, and it is sent to
+ * write-out phase for reclaim
+ * 2. The stripe is clean, and this is the first write
+ *
+ * For 1, return -EAGAIN, so we continue with
+ * handle_stripe_dirtying().
+ *
+ * For 2, set STRIPE_R5C_CACHING and continue with caching
+ * write.
+ */
+
+ /* case 1: anything injournal or anything in written */
+ if (s->injournal > 0 || s->written > 0)
+ return -EAGAIN;
+ /* case 2 */
+ set_bit(STRIPE_R5C_CACHING, &sh->state);
+ }
+
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ /* if non-overwrite, use writing-out phase */
+ if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
+ !test_bit(R5_InJournal, &dev->flags)) {
+ r5c_make_stripe_write_out(sh);
+ return -EAGAIN;
+ }
+ }
+
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ if (dev->towrite) {
+ set_bit(R5_Wantwrite, &dev->flags);
+ set_bit(R5_Wantdrain, &dev->flags);
+ set_bit(R5_LOCKED, &dev->flags);
+ to_cache++;
+ }
+ }
+
+ if (to_cache) {
+ set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
+ /*
+ * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
+ * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
+ * r5c_handle_data_cached()
+ */
+ set_bit(STRIPE_LOG_TRAPPED, &sh->state);
+ }
+
+ return 0;
+}
+
+/*
+ * free extra pages (orig_page) we allocated for prexor
+ */
+void r5c_release_extra_page(struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+ int i;
+ bool using_disk_info_extra_page;
+
+ using_disk_info_extra_page =
+ sh->dev[0].orig_page == conf->disks[0].extra_page;
+
+ for (i = sh->disks; i--; )
+ if (sh->dev[i].page != sh->dev[i].orig_page) {
+ struct page *p = sh->dev[i].orig_page;
+
+ sh->dev[i].orig_page = sh->dev[i].page;
+ if (!using_disk_info_extra_page)
+ put_page(p);
+ }
+
+ if (using_disk_info_extra_page) {
+ clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
+ md_wakeup_thread(conf->mddev->thread);
+ }
+}
+
+void r5c_use_extra_page(struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+ int i;
+ struct r5dev *dev;
+
+ for (i = sh->disks; i--; ) {
+ dev = &sh->dev[i];
+ if (dev->orig_page != dev->page)
+ put_page(dev->orig_page);
+ dev->orig_page = conf->disks[i].extra_page;
+ }
+}
+
+/*
+ * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
+ * stripe is committed to RAID disks.
+ */
+void r5c_finish_stripe_write_out(struct r5conf *conf,
+ struct stripe_head *sh,
+ struct stripe_head_state *s)
+{
+ int i;
+ int do_wakeup = 0;
+
+ if (!conf->log ||
+ !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
+ return;
+
+ WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
+ clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
+
+ if (conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
+ return;
+
+ for (i = sh->disks; i--; ) {
+ clear_bit(R5_InJournal, &sh->dev[i].flags);
+ if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
+ do_wakeup = 1;
+ }
+
+ /*
+ * analyse_stripe() runs before r5c_finish_stripe_write_out(),
+ * We updated R5_InJournal, so we also update s->injournal.
+ */
+ s->injournal = 0;
+
+ if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
+ if (atomic_dec_and_test(&conf->pending_full_writes))
+ md_wakeup_thread(conf->mddev->thread);
+
+ if (do_wakeup)
+ wake_up(&conf->wait_for_overlap);
+
+ if (conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
+ return;
+
+ spin_lock_irq(&conf->log->stripe_in_journal_lock);
+ list_del_init(&sh->r5c);
+ spin_unlock_irq(&conf->log->stripe_in_journal_lock);
+ sh->log_start = MaxSector;
+ atomic_dec(&conf->log->stripe_in_journal_count);
+ r5c_update_log_state(conf->log);
+}
+
+int
+r5c_cache_data(struct r5l_log *log, struct stripe_head *sh,
+ struct stripe_head_state *s)
+{
+ struct r5conf *conf = sh->raid_conf;
+ int pages = 0;
+ int reserve;
+ int i;
+ int ret = 0;
+
+ BUG_ON(!log);
+
+ for (i = 0; i < sh->disks; i++) {
+ void *addr;
+
+ if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
+ continue;
+ addr = kmap_atomic(sh->dev[i].page);
+ sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
+ addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ pages++;
+ }
+ WARN_ON(pages == 0);
+
+ /*
+ * The stripe must enter state machine again to call endio, so
+ * don't delay.
+ */
+ clear_bit(STRIPE_DELAYED, &sh->state);
+ atomic_inc(&sh->count);
+
+ mutex_lock(&log->io_mutex);
+ /* meta + data */
+ reserve = (1 + pages) << (PAGE_SHIFT - 9);
+
+ if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
+ sh->log_start == MaxSector)
+ r5l_add_no_space_stripe(log, sh);
+ else if (!r5l_has_free_space(log, reserve)) {
+ if (sh->log_start == log->last_checkpoint)
+ BUG();
+ else
+ r5l_add_no_space_stripe(log, sh);
+ } else {
+ ret = r5l_log_stripe(log, sh, pages, 0);
+ if (ret) {
+ spin_lock_irq(&log->io_list_lock);
+ list_add_tail(&sh->log_list, &log->no_mem_stripes);
+ spin_unlock_irq(&log->io_list_lock);
+ }
+ }
+
+ mutex_unlock(&log->io_mutex);
+ return 0;
}
static int r5l_load_log(struct r5l_log *log)
@@ -1121,7 +2494,7 @@ static int r5l_load_log(struct r5l_log *log)
sector_t cp = log->rdev->journal_tail;
u32 stored_crc, expected_crc;
bool create_super = false;
- int ret;
+ int ret = 0;
/* Make sure it's valid */
if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
@@ -1171,11 +2544,18 @@ create:
if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
log->max_free_space = RECLAIM_MAX_FREE_SPACE;
log->last_checkpoint = cp;
- log->next_checkpoint = cp;
__free_page(page);
- return r5l_recovery_log(log);
+ if (create_super) {
+ log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
+ log->seq = log->last_cp_seq + 1;
+ log->next_checkpoint = cp;
+ } else
+ ret = r5l_recovery_log(log);
+
+ r5c_update_log_state(log);
+ return ret;
ioerr:
__free_page(page);
return ret;
@@ -1188,6 +2568,22 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
if (PAGE_SIZE != 4096)
return -EINVAL;
+
+ /*
+ * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
+ * raid_disks r5l_payload_data_parity.
+ *
+ * Write journal and cache does not work for very big array
+ * (raid_disks > 203)
+ */
+ if (sizeof(struct r5l_meta_block) +
+ ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
+ conf->raid_disks) > PAGE_SIZE) {
+ pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
+ mdname(conf->mddev), conf->raid_disks);
+ return -EINVAL;
+ }
+
log = kzalloc(sizeof(*log), GFP_KERNEL);
if (!log)
return -ENOMEM;
@@ -1227,6 +2623,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
log->rdev->mddev, "reclaim");
if (!log->reclaim_thread)
goto reclaim_thread;
+ log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
+
init_waitqueue_head(&log->iounit_wait);
INIT_LIST_HEAD(&log->no_mem_stripes);
@@ -1234,6 +2632,13 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
INIT_LIST_HEAD(&log->no_space_stripes);
spin_lock_init(&log->no_space_stripes_lock);
+ INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
+
+ log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
+ INIT_LIST_HEAD(&log->stripe_in_journal_list);
+ spin_lock_init(&log->stripe_in_journal_lock);
+ atomic_set(&log->stripe_in_journal_count, 0);
+
if (r5l_load_log(log))
goto error;