4.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Sterba <[email protected]> [ Upstream commit 399f7f4c42e8a58c8456264d5112287aefe44cf4 ] In preparation to take a big lock, move resource initialization before the critical section. It's not obvious from the diff, the desired order is: - initialize mount security options - allocate temporary fs_info - allocate superblock buffers Reviewed-by: Anand Jain <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/btrfs/super.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1528,14 +1528,6 @@ static struct dentry *btrfs_mount_root(s if (!(flags & SB_RDONLY)) mode |= FMODE_WRITE; - mutex_lock(&uuid_mutex); - error = btrfs_parse_early_options(data, mode, fs_type, - &fs_devices); - mutex_unlock(&uuid_mutex); - if (error) { - return ERR_PTR(error); - } - security_init_mnt_opts(&new_sec_opts); if (data) { error = parse_security_options(data, &new_sec_opts); @@ -1543,12 +1535,6 @@ static struct dentry *btrfs_mount_root(s return ERR_PTR(error); } - mutex_lock(&uuid_mutex); - error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); - mutex_unlock(&uuid_mutex); - if (error) - goto error_sec_opts; - /* * Setup a dummy root and fs_info for test/set super. This is because * we don't actually fill this stuff out until open_ctree, but we need @@ -1561,8 +1547,6 @@ static struct dentry *btrfs_mount_root(s goto error_sec_opts; } - fs_info->fs_devices = fs_devices; - fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); security_init_mnt_opts(&fs_info->security_opts); @@ -1572,6 +1556,20 @@ static struct dentry *btrfs_mount_root(s } mutex_lock(&uuid_mutex); + error = btrfs_parse_early_options(data, mode, fs_type, &fs_devices); + mutex_unlock(&uuid_mutex); + if (error) + goto error_fs_info; + + mutex_lock(&uuid_mutex); + error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); + mutex_unlock(&uuid_mutex); + if (error) + goto error_fs_info; + + fs_info->fs_devices = fs_devices; + + mutex_lock(&uuid_mutex); error = btrfs_open_devices(fs_devices, mode, fs_type); mutex_unlock(&uuid_mutex); if (error)
