diff options
| author | NeilBrown <neilb@suse.de> | 2014-09-09 07:49:46 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-06 00:41:10 +0400 |
| commit | dd777df4ddcec4e3cac323c22f78eb22591d2c20 (patch) | |
| tree | 21588b5d52b999104b0618fa9fb52ddcab455037 | |
| parent | 3ab661d945090ce254bea99d82989cddb5589e2d (diff) | |
| download | linux-dd777df4ddcec4e3cac323c22f78eb22591d2c20.tar.xz | |
md/raid1: be more cautious where we read-balance during resync.
commit c6d119cf1b5a778e9ed60a006e2a434fcc4471a2 upstream.
commit 79ef3a8aa1cb1523cc231c9a90a278333c21f761 made
it possible for reads to happen concurrently with resync.
This means that we need to be more careful where read_balancing
is allowed during resync - we can no longer be sure that any
resync that has already started will definitely finish.
So keep read_balancing to before recovery_cp, which is conservative
but safe.
This bug makes it possible to read from a device that doesn't
have up-to-date data, so it can cause data corruption.
So it is suitable for any kernel since 3.11.
Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/raid1.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 3aa305f5a9af..65afd8aa6608 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -540,11 +540,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect has_nonrot_disk = 0; choose_next_idle = 0; - if (conf->mddev->recovery_cp < MaxSector && - (this_sector + sectors >= conf->next_resync)) - choose_first = 1; - else - choose_first = 0; + choose_first = (conf->mddev->recovery_cp < this_sector + sectors); for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { sector_t dist; |