diff options
| author | NeilBrown <neilb@suse.de> | 2012-12-11 03:35:54 +0100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2012-12-11 03:35:54 +0100 |
| commit | a7a3f08dc24690ae00c75cfe4b4701a970dd0155 (patch) | |
| tree | bc9174cc50feba550a33148e661dc57ac37950dd /drivers/md/md.c | |
| parent | md: removed unused variable in calc_sb_1_csm. (diff) | |
| download | linux-a7a3f08dc24690ae00c75cfe4b4701a970dd0155.tar.xz linux-a7a3f08dc24690ae00c75cfe4b4701a970dd0155.zip | |
md: close race between removing and adding a device.
When we remove a device from an md array, the final removal of
the "dev-XX" sys entry is run asynchronously.
If we then re-add that device immediately before the worker thread
gets to run, we can end up trying to add the "dev-XX" sysfs entry back
before it has been removed.
So in both places where we add a device, call
flush_workqueue(md_misc_wq);
before taking the md lock (as holding the md lock can prevent removal
to complete).
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 89dbd444517e..8b0e3d21f736 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4752,6 +4752,8 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, } mddev_get(mddev); spin_unlock(&all_mddevs_lock); + if (entry->store == new_dev_store) + flush_workqueue(md_misc_wq); rv = mddev_lock(mddev); if (!rv) { rv = entry->store(mddev, page, length); @@ -6397,6 +6399,10 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, goto abort; } + if (cmd == ADD_NEW_DISK) + /* need to ensure md_delayed_delete() has completed */ + flush_workqueue(md_misc_wq); + err = mddev_lock(mddev); if (err) { printk(KERN_INFO |