We got a recursive lock in mksubvol because the caller already held a lock. I think we got into this due to a merge error. Commit a874a63 removed the mnt_want_write call from btrfs_mksubvol and added a replacement call to mnt_want_write_file in btrfs_ioctl_snap_create_transid. Commit e7848683 however tried to move all calls to mnt_want_write above i_mutex. So somewhere while merging this, it got mixed up. The solution is to remove the mnt_want_write call completely from mksubvol. Reported-by: David Sterba <dave@xxxxxxxx> Signed-off-by: Alexander Block <ablock84@xxxxxxxxxxxxxx> --- fs/btrfs/ioctl.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 00ddf22..9df50fa 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -664,10 +664,6 @@ static noinline int btrfs_mksubvol(struct path *parent, struct dentry *dentry; int error; - error = mnt_want_write(parent->mnt); - if (error) - return error; - mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); dentry = lookup_one_len(name, parent->dentry, namelen); @@ -703,7 +699,6 @@ out_dput: dput(dentry); out_unlock: mutex_unlock(&dir->i_mutex); - mnt_drop_write(parent->mnt); return error; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
