btrfs: Add datasum mount option.

Add datasum mount option to enable checksum with
remount option.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt
index bbd1f0f57ce9e409ad3d35008879ba36b58ab2d9..e05c6aecc0cc38d2b8b3046b437f30dd12125473 100644 (file)
--- a/Documentation/filesystems/btrfs.txt
+++ b/Documentation/filesystems/btrfs.txt
@@ -159,8 +159,10 @@ Options with (*) are default options and will not show in the mount options.
        Enable/disable data copy-on-write for newly created files.
        Nodatacow implies nodatasum, and disables all compression.
 
+  datasum(*)
   nodatasum
-       Disable data checksumming for newly created files.
+       Enable/disable data checksumming for newly created files.
+       Datasum implies datacow.
 
   notreelog
        Disable the tree logging used for fsync and O_SYNC writes.

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 6567865a25049c624ed9abdfbcc21f726e6783e0..e84e6cb575262db8bdbbfe3b174d653eb32c3fc4 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -325,6 +325,7 @@ enum {
        Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
        Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
        Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
+       Opt_datasum,
        Opt_err,
 };
 
@@ -334,6 +335,7 @@ static match_table_t tokens = {
        {Opt_subvolid, "subvolid=%s"},
        {Opt_device, "device=%s"},
        {Opt_nodatasum, "nodatasum"},
+       {Opt_datasum, "datasum"},
        {Opt_nodatacow, "nodatacow"},
        {Opt_datacow, "datacow"},
        {Opt_nobarrier, "nobarrier"},
@@ -434,6 +436,14 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        btrfs_info(root->fs_info, "setting nodatasum");
                        btrfs_set_opt(info->mount_opt, NODATASUM);
                        break;
+               case Opt_datasum:
+                       if (btrfs_test_opt(root, NODATACOW))
+                               btrfs_info(root->fs_info, "setting datasum, datacow enabled");
+                       else
+                               btrfs_info(root->fs_info, "setting datasum");
+                       btrfs_clear_opt(info->mount_opt, NODATACOW);
+                       btrfs_clear_opt(info->mount_opt, NODATASUM);
+                       break;
                case Opt_nodatacow:
                        if (!btrfs_test_opt(root, COMPRESS) ||
                                !btrfs_test_opt(root, FORCE_COMPRESS)) {