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@xxxxxxxxx>
---
drivers/md/md.c | 20 ++++++++------------
drivers/md/md.h | 2 +-
drivers/md/raid1.c | 9 +++------
drivers/md/raid5.c | 12 +++---------
4 files changed, 15 insertions(+), 28 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);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 4e75d121bfcc..11f15146ce51 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -665,7 +665,7 @@ extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
bool metadata_op);
extern void md_do_sync(struct md_thread *thread);
extern void md_new_event(struct mddev *mddev);
-extern int md_allow_write(struct mddev *mddev);
+extern void md_allow_write(struct mddev *mddev);
extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev);
extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors);
extern int md_check_no_bitmap(struct mddev *mddev);
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 7ed59351fe97..7c1f73398800 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3197,7 +3197,7 @@ static int raid1_reshape(struct mddev *mddev)
struct r1conf *conf = mddev->private;
int cnt, raid_disks;
unsigned long flags;
- int d, d2, err;
+ int d, d2;
/* Cannot change chunk_size, layout, or level */
if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
@@ -3209,11 +3209,8 @@ static int raid1_reshape(struct mddev *mddev)
return -EINVAL;
}
- if (!mddev_is_clustered(mddev)) {
- err = md_allow_write(mddev);
- if (err)
- return err;
- }
+ if (!mddev_is_clustered(mddev))
+ md_allow_write(mddev);
raid_disks = mddev->raid_disks + mddev->delta_disks;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 3809a2192132..f8055a7abb4b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2309,14 +2309,12 @@ static int resize_stripes(struct r5conf *conf, int newsize)
struct stripe_head *osh, *nsh;
LIST_HEAD(newstripes);
struct disk_info *ndisks;
- int err;
+ int err = 0;
struct kmem_cache *sc;
int i;
int hash, cnt;
- err = md_allow_write(conf->mddev);
- if (err)
- return err;
+ md_allow_write(conf->mddev);
/* Step 1 */
sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
@@ -6310,7 +6308,6 @@ int
raid5_set_cache_size(struct mddev *mddev, int size)
{
struct r5conf *conf = mddev->private;
- int err;
if (size <= 16 || size > 32768)
return -EINVAL;
@@ -6322,10 +6319,7 @@ raid5_set_cache_size(struct mddev *mddev, int size)
;
mutex_unlock(&conf->cache_size_mutex);
-
- err = md_allow_write(mddev);
- if (err)
- return err;
+ md_allow_write(mddev);
mutex_lock(&conf->cache_size_mutex);
while (size > conf->max_nr_stripes)
--
2.11.0
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