@@ -159,9 +159,10 @@ Options with (*) are default options and will not show in the mount options.
(non-battery-backed) write-back cache, this option will lead to
filesystem corruption on a system crash or power loss.
+ datacow(*)
nodatacow
- Disable data copy-on-write for newly created files. Implies nodatasum,
- and disables all compression.
+ Enable/disable data copy-on-write for newly created files.
+ Nodatacow implies nodatasum, and disables all compression.
nodatasum
Disable data checksumming for newly created files.
@@ -325,7 +325,7 @@ enum {
Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nocheck_integrity,
Opt_nodiscard, Opt_noenospc_debug, Opt_noflushoncommit,
- Opt_noinode_cache, Opt_acl,
+ Opt_noinode_cache, Opt_acl, Opt_datacow,
Opt_err,
};
@@ -336,6 +336,7 @@ static match_table_t tokens = {
{Opt_device, "device=%s"},
{Opt_nodatasum, "nodatasum"},
{Opt_nodatacow, "nodatacow"},
+ {Opt_datacow, "datacow"},
{Opt_nobarrier, "nobarrier"},
{Opt_barrier, "barrier"},
{Opt_max_inline, "max_inline=%s"},
@@ -449,6 +450,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
btrfs_set_opt(info->mount_opt, NODATACOW);
btrfs_set_opt(info->mount_opt, NODATASUM);
break;
+ case Opt_datacow:
+ if (btrfs_test_opt(root, NODATACOW))
+ btrfs_info(root->fs_info, "setting datacow");
+ btrfs_clear_opt(info->mount_opt, NODATACOW);
+ break;
case Opt_compress_force:
case Opt_compress_force_type:
compress_force = true;
Add datacow mount option to enable copy-on-write with remount option. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- changelog: v2: Add datacow mount option. --- Documentation/filesystems/btrfs.txt | 5 +++-- fs/btrfs/super.c | 8 +++++++- 2 files changed, 10 insertions(+), 3 deletions(-)