diff options
| author | David Sterba <dsterba@suse.com> | 2022-07-26 20:54:10 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-12-05 18:00:41 +0100 |
| commit | 63a7cb13071842966c1ce931edacbc23573aada5 (patch) | |
| tree | f888ce16a46f6aad0414e3457b15f0bcf416e615 /fs/btrfs/disk-io.c | |
| parent | 467761f90405004e58795116aa7d81f3d298dcfb (diff) | |
btrfs: auto enable discard=async when possible
There's a request to automatically enable async discard for capable
devices. We can do that, the async mode is designed to wait for larger
freed extents and is not intrusive, with limits to iops, kbps or latency.
The status and tunables will be exported in /sys/fs/btrfs/FSID/discard .
The automatic selection is done if there's at least one discard capable
device in the filesystem (not capable devices are skipped). Mounting
with any other discard option will honor that option, notably mounting
with nodiscard will keep it disabled.
Link: https://lore.kernel.org/linux-btrfs/CAEg-Je_b1YtdsCR0zS5XZ_SbvJgN70ezwvRwLiCZgDGLbeMB=w@mail.gmail.com/
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 5705335c80c8..cf59d8f14a05 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3747,6 +3747,20 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device } /* + * For devices supporting discard turn on discard=async automatically, + * unless it's already set or disabled. This could be turned off by + * nodiscard for the same mount. + */ + if (!(btrfs_test_opt(fs_info, DISCARD_SYNC) || + btrfs_test_opt(fs_info, DISCARD_ASYNC) || + btrfs_test_opt(fs_info, NODISCARD)) && + fs_info->fs_devices->discardable) { + btrfs_set_and_info(fs_info, DISCARD_ASYNC, + "auto enabling async discard"); + btrfs_clear_opt(fs_info->mount_opt, NODISCARD); + } + + /* * Mount does not set all options immediately, we can do it now and do * not have to wait for transaction commit */ |