diff options
| author |   Artur Paszkiewicz <artur.paszkiewicz@intel.com> | 2017-05-08 11:56:55 +0200 |
|---|---|---|
| committer |   Shaohua Li <shli@fb.com> | 2017-05-08 10:32:59 -0700 |
| commit | 2214c260c72b0bd94e6c1c19bf451686212025d3 (patch) | |
| tree | 829a3494857d6bd61c38171a39e2e207de585e38 /drivers/md/md.c | |
| parent | md/raid5: make use of spin_lock_irq over local_irq_disable + spin_lock (diff) | |
| download | linux-dev-2214c260c72b0bd94e6c1c19bf451686212025d3.tar.xz linux-dev-2214c260c72b0bd94e6c1c19bf451686212025d3.zip | |
md: don't return -EAGAIN in md_allow_write for external metadata arrays
This essentially reverts commit b5470dc5fc18 ("md: resolve external
metadata handling deadlock in md_allow_write") with some adjustments.
Since commit 6791875e2e53 ("md: make reconfig_mutex optional for writes
to md sysfs files.") changing array_state to 'active' does not use
mddev_lock() and will not cause a deadlock with md_allow_write(). This
revert simplifies userspace tools that write to sysfs attributes like
"stripe_cache_size" or "consistency_policy" because it removes the need
for special handling for external metadata arrays, checking for EAGAIN
and retrying the write.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 82f798be964f..10367ffe92e3 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8022,18 +8022,15 @@ EXPORT_SYMBOL(md_write_end); * may proceed without blocking. It is important to call this before * attempting a GFP_KERNEL allocation while holding the mddev lock. * Must be called with mddev_lock held. - * - * In the ->external case MD_SB_CHANGE_PENDING can not be cleared until mddev->lock - * is dropped, so return -EAGAIN after notifying userspace. */ -int md_allow_write(struct mddev *mddev) +void md_allow_write(struct mddev *mddev) { if (!mddev->pers) - return 0; + return; if (mddev->ro) - return 0; + return; if (!mddev->pers->sync_request) - return 0; + return; spin_lock(&mddev->lock); if (mddev->in_sync) { @@ -8046,13 +8043,12 @@ int md_allow_write(struct mddev *mddev) spin_unlock(&mddev->lock); md_update_sb(mddev, 0); sysfs_notify_dirent_safe(mddev->sysfs_state); + /* wait for the dirty state to be recorded in the metadata */ + wait_event(mddev->sb_wait, + !test_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags) && + !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)); } else spin_unlock(&mddev->lock); - - if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) - return -EAGAIN; - else - return 0; } EXPORT_SYMBOL_GPL(md_allow_write); |