diff options
| author | Liu Bo <bo.li.liu@oracle.com> | 2015-08-14 18:33:07 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2015-10-01 18:07:59 +0200 |
| commit | 73416dab235e5ff030e3b3c61da0cd6ced324fc9 (patch) | |
| tree | eacb4410f3b1e79be065d826cc7894441fafc3c1 | |
| parent | f190aa471a7a703444f6587ed79c24a04a22d848 (diff) | |
Btrfs: move kobj stuff out of dev_replace lock range
To avoid deadlock described in commit 084b6e7c7607 ("btrfs: Fix a
lockdep warning when running xfstest."), we should move kobj stuff out
of dev_replace lock range.
"It is because the btrfs_kobj_{add/rm}_device() will call memory
allocation with GFP_KERNEL,
which may flush fs page cache to free space, waiting for it self to do
the commit, causing the deadlock.
To solve the problem, move btrfs_kobj_{add/rm}_device() out of the
dev_replace lock range, also involing split the
btrfs_rm_dev_replace_srcdev() function into remove and free parts.
Now only btrfs_rm_dev_replace_remove_srcdev() is called in dev_replace
lock range, and kobj_{add/rm} and btrfs_rm_dev_replace_free_srcdev() are
called out of the lock range."
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[added lockup description]
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/dev-replace.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 02031fc07f7f..0978e52ffa42 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -375,10 +375,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root, WARN_ON(!tgt_device); dev_replace->tgtdev = tgt_device; - ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); - if (ret) - btrfs_err(root->fs_info, "kobj add dev failed %d\n", ret); - printk_in_rcu(KERN_INFO "BTRFS: dev_replace from %s (devid %llu) to %s started\n", src_device->missing ? "<missing disk>" : @@ -401,6 +397,10 @@ int btrfs_dev_replace_start(struct btrfs_root *root, args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; btrfs_dev_replace_unlock(dev_replace); + ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); + if (ret) + btrfs_err(root->fs_info, "kobj add dev failed %d\n", ret); + btrfs_wait_ordered_roots(root->fs_info, -1); /* force writing the updated state information to disk */ |