From: Alexander Block Date: Thu, 2 Aug 2012 23:16:20 +0000 (-0600) Subject: Btrfs: remove mnt_want_write call in btrfs_mksubvol X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e00da2067b78a9246f767012a3803224c40b1f9f;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git Btrfs: remove mnt_want_write call in btrfs_mksubvol 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 Signed-off-by: Alexander Block Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index bc2f6ffff3cf..7bb755677a22 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; }