diff options
| -rw-r--r-- | Documentation/filesystems/btrfs.txt | 7 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 6 |
2 files changed, 10 insertions, 3 deletions
diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt index e87609a4e21c..7254cf501391 100644 --- a/Documentation/filesystems/btrfs.txt +++ b/Documentation/filesystems/btrfs.txt @@ -98,9 +98,12 @@ Options with (*) are default options and will not show in the mount options. can be avoided. Especially useful when trying to mount a multi-device setup as root. May be specified multiple times for multiple devices. + nodiscard(*) discard - Issue frequent commands to let the block device reclaim space freed by - the filesystem. This is useful for SSD devices, thinly provisioned + Disable/enable discard mount option. + Discard issues frequent commands to let the block device reclaim space + freed by the filesystem. + This is useful for SSD devices, thinly provisioned LUNs and virtual machine images, but may have a significant performance impact. (The fstrim command is also available to initiate batch trims from userspace). diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 44513f3fbdc1..e15377035dd5 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -323,7 +323,7 @@ enum { Opt_no_space_cache, Opt_recovery, Opt_skip_balance, Opt_check_integrity, Opt_check_integrity_including_extent_data, Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, - Opt_commit_interval, Opt_barrier, Opt_nodefrag, + Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, Opt_err, }; @@ -351,6 +351,7 @@ static match_table_t tokens = { {Opt_flushoncommit, "flushoncommit"}, {Opt_ratio, "metadata_ratio=%d"}, {Opt_discard, "discard"}, + {Opt_nodiscard, "nodiscard"}, {Opt_space_cache, "space_cache"}, {Opt_clear_cache, "clear_cache"}, {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, @@ -575,6 +576,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) case Opt_discard: btrfs_set_opt(info->mount_opt, DISCARD); break; + case Opt_nodiscard: + btrfs_clear_opt(info->mount_opt, DISCARD); + break; case Opt_space_cache: btrfs_set_opt(info->mount_opt, SPACE_CACHE); break; |