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| author | Shaohua Li | 2015-12-21 00:51:02 +0100 |
|---|---|---|
| committer | NeilBrown | 2016-01-06 01:39:57 +0100 |
| commit | f6b6ec5cfac306c1eea66f074050864efcb11851 (patch) | |
| tree | 68c0b7210bb1ce3f23bf59332c47ef35d09cf8eb /drivers/md/raid5-cache.c | |
| parent | drivers: md: use ktime_get_real_seconds() (diff) | |
| download | kernel-qcow2-linux-f6b6ec5cfac306c1eea66f074050864efcb11851.tar.gz kernel-qcow2-linux-f6b6ec5cfac306c1eea66f074050864efcb11851.tar.xz kernel-qcow2-linux-f6b6ec5cfac306c1eea66f074050864efcb11851.zip | |
raid5-cache: add journal hot add/remove support
Add support for journal disk hot add/remove. Mostly trival checks in md
part. The raid5 part is a little tricky. For hot-remove, we can't wait
pending write as it's called from raid5d. The wait will cause deadlock.
We simplily fail the hot-remove. A hot-remove retry can success
eventually since if journal disk is faulty all pending write will be
failed and finish. For hot-add, since an array supporting journal but
without journal disk will be marked read-only, we are safe to hot add
journal without stopping IO (should be read IO, while journal only
handles write IO).
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers/md/raid5-cache.c')
| -rw-r--r-- | drivers/md/raid5-cache.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 668e973f07e6..c1c4d213a2c2 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -799,10 +799,18 @@ void r5l_quiesce(struct r5l_log *log, int state) bool r5l_log_disk_error(struct r5conf *conf) { + struct r5l_log *log; + bool ret; /* don't allow write if journal disk is missing */ - if (!conf->log) - return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags); - return test_bit(Faulty, &conf->log->rdev->flags); + rcu_read_lock(); + log = rcu_dereference(conf->log); + + if (!log) + ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags); + else + ret = test_bit(Faulty, &log->rdev->flags); + rcu_read_unlock(); + return ret; } struct r5l_recovery_ctx { @@ -1165,7 +1173,7 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) if (r5l_load_log(log)) goto error; - conf->log = log; + rcu_assign_pointer(conf->log, log); return 0; error: md_unregister_thread(&log->reclaim_thread); |