diff options
| author | Jan Kara <jack@suse.cz> | 2012-06-12 16:20:32 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-07-31 01:02:51 +0400 |
| commit | e7848683ae7ded0a4a8964122a47da9104a98337 (patch) | |
| tree | 7dc006d60d73c1c37b74bc4127ecfe0209517230 /fs | |
| parent | e24f17da3560781e274699f066fb788ad52f4402 (diff) | |
| download | linux-stable-e7848683ae7ded0a4a8964122a47da9104a98337.tar.gz linux-stable-e7848683ae7ded0a4a8964122a47da9104a98337.tar.bz2 linux-stable-e7848683ae7ded0a4a8964122a47da9104a98337.zip | |
btrfs: Push mnt_want_write() outside of i_mutex
When mnt_want_write() starts to handle freezing it will get a full lock
semantics requiring proper lock ordering. So push mnt_want_write() call
consistently outside of i_mutex.
CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/ioctl.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 1e9f6c019ad0..cd93eb530b74 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -193,6 +193,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) if (!inode_owner_or_capable(inode)) return -EACCES; + ret = mnt_want_write_file(file); + if (ret) + return ret; + mutex_lock(&inode->i_mutex); ip_oldflags = ip->flags; @@ -207,10 +211,6 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) } } - ret = mnt_want_write_file(file); - if (ret) - goto out_unlock; - if (flags & FS_SYNC_FL) ip->flags |= BTRFS_INODE_SYNC; else @@ -273,9 +273,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) inode->i_flags = i_oldflags; } - mnt_drop_write_file(file); out_unlock: mutex_unlock(&inode->i_mutex); + mnt_drop_write_file(file); return ret; } @@ -641,6 +641,10 @@ 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); @@ -652,13 +656,9 @@ static noinline int btrfs_mksubvol(struct path *parent, if (dentry->d_inode) goto out_dput; - error = mnt_want_write(parent->mnt); - if (error) - goto out_dput; - error = btrfs_may_create(dir, dentry); if (error) - goto out_drop_write; + goto out_dput; down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); @@ -676,12 +676,11 @@ static noinline int btrfs_mksubvol(struct path *parent, fsnotify_mkdir(dir, dentry); out_up_read: up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); -out_drop_write: - mnt_drop_write(parent->mnt); out_dput: dput(dentry); out_unlock: mutex_unlock(&dir->i_mutex); + mnt_drop_write(parent->mnt); return error; } |