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| author |   NeilBrown <neilb@suse.de> | 2014-09-10 15:01:49 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2014-09-22 11:26:01 +1000 |
| commit | 2f73d3c55d09ce60647b96ad2a9b539c95a530ee (patch) | |
| tree | 0db851e83a73d78afd9056063fec19656d02c9e3 /drivers/md | |
| parent | md/raid1: clean up request counts properly in close_sync() (diff) | |
| download | linux-dev-2f73d3c55d09ce60647b96ad2a9b539c95a530ee.tar.xz linux-dev-2f73d3c55d09ce60647b96ad2a9b539c95a530ee.zip | |
md/raid1: make sure resync waits for conflicting writes to complete.
The resync/recovery process for raid1 was recently changed
so that writes could happen in parallel with resync providing
they were in different regions of the device.
There is a problem though: While a write request will always
wait for conflicting resync to complete, a resync request
will *not* always wait for conflicting writes to complete.
Two changes are needed to fix this:
1/ raise_barrier (which waits until it is safe to do resync)
must wait until current_window_requests is zero
2/ wait_battier (which waits at the start of a new write request)
must update current_window_requests if the request could
possible conflict with a concurrent resync.
As concurrent writes and resync can lead to data loss,
this patch is suitable for -stable.
Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761
Cc: stable@vger.kernel.org (v3.13+)
Cc: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid1.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index a31c92bbcfc9..b13c218997da 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -845,10 +845,12 @@ static void raise_barrier(struct r1conf *conf) * C: next_resync + RESYNC_SECTORS > start_next_window, meaning * next resync will reach to the window which normal bios are * handling. + * D: while there are any active requests in the current window. */ wait_event_lock_irq(conf->wait_barrier, !conf->array_frozen && conf->barrier < RESYNC_DEPTH && + conf->current_window_requests == 0 && (conf->start_next_window >= conf->next_resync + RESYNC_SECTORS), conf->resync_lock); @@ -915,8 +917,8 @@ static sector_t wait_barrier(struct r1conf *conf, struct bio *bio) } if (bio && bio_data_dir(bio) == WRITE) { - if (conf->next_resync + NEXT_NORMALIO_DISTANCE - <= bio->bi_iter.bi_sector) { + if (bio->bi_iter.bi_sector >= + conf->next_resync) { if (conf->start_next_window == MaxSector) conf->start_next_window = conf->next_resync + |