md/raid5-cache: clear MD_SB_CHANGE_PENDING before flushing stripes

In recovery, if we process too much data, raid5-cache may set
MD_SB_CHANGE_PENDING, which causes spinning in handle_stripe().
Fix this issue by clearing the bit before flushing data only
stripes. This issue was initially discussed in [1].

[1] https://www.spinics.net/lists/raid/msg64409.html

Signed-off-by: Song Liu <songliubraving@fb.com>
This commit is contained in:
Song Liu 2020-07-06 14:57:32 -07:00
parent e1a86dbbbd
commit c9020e64cf

View file

@ -2430,10 +2430,15 @@ static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
struct mddev *mddev = log->rdev->mddev; struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private; struct r5conf *conf = mddev->private;
struct stripe_head *sh, *next; struct stripe_head *sh, *next;
bool cleared_pending = false;
if (ctx->data_only_stripes == 0) if (ctx->data_only_stripes == 0)
return; return;
if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
cleared_pending = true;
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
}
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK; log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) { list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
@ -2448,6 +2453,8 @@ static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
atomic_read(&conf->active_stripes) == 0); atomic_read(&conf->active_stripes) == 0);
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH; log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
if (cleared_pending)
set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
} }
static int r5l_recovery_log(struct r5l_log *log) static int r5l_recovery_log(struct r5l_log *log)