Commit cc53bd20 authored by David Sterba's avatar David Sterba
Browse files

btrfs: add unlikely annotations to branches leading to EIO 



The unlikely() annotation is a static prediction hint that compiler may
use to reorder code out of hot path. We use it elsewhere (namely
tree-checker.c) for error branches that almost never happen, where
EIO is one of them.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 9264d004

fs/btrfs/backref.c

+2 −2
Original line number Diff line number Diff line
@@ -859,7 +859,7 @@ static int add_missing_keys(struct btrfs_fs_info *fs_info, 
			free_pref(ref);

			return PTR_ERR(eb);

		}

		if (!extent_buffer_uptodate(eb)) {

		if (unlikely(!extent_buffer_uptodate(eb))) {

			free_pref(ref);

			free_extent_buffer(eb);

			return -EIO;
@@ -1614,7 +1614,7 @@ static int find_parent_nodes(struct btrfs_backref_walk_ctx *ctx, 
					ret = PTR_ERR(eb);

					goto out;

				}

				if (!extent_buffer_uptodate(eb)) {

				if (unlikely(!extent_buffer_uptodate(eb))) {

					free_extent_buffer(eb);

					ret = -EIO;

					goto out;

fs/btrfs/bio.c

+2 −2
Original line number Diff line number Diff line
@@ -849,8 +849,8 @@ int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start, 
	if (ret < 0)

		goto out_counter_dec;



	if (!smap.dev->bdev ||

	    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &smap.dev->dev_state)) {

	if (unlikely(!smap.dev->bdev ||

		     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &smap.dev->dev_state))) {

		ret = -EIO;

		goto out_counter_dec;

	}

fs/btrfs/defrag.c

+1 −1
Original line number Diff line number Diff line
@@ -924,7 +924,7 @@ static struct folio *defrag_prepare_one_folio(struct btrfs_inode *inode, pgoff_t 
			folio_put(folio);

			goto again;

		}

		if (!folio_test_uptodate(folio)) {

		if (unlikely(!folio_test_uptodate(folio))) {

			folio_unlock(folio);

			folio_put(folio);

			return ERR_PTR(-EIO);

fs/btrfs/dev-replace.c

+2 −4
Original line number Diff line number Diff line
@@ -177,8 +177,7 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 
		 * allow 'btrfs dev replace_cancel' if src/tgt device is

		 * missing

		 */

		if (!dev_replace->srcdev &&

		    !btrfs_test_opt(fs_info, DEGRADED)) {

		if (unlikely(!dev_replace->srcdev && !btrfs_test_opt(fs_info, DEGRADED))) {

			ret = -EIO;

			btrfs_warn(fs_info,

			   "cannot mount because device replace operation is ongoing and");
@@ -186,8 +185,7 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) 
			   "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?",

			   src_devid);

		}

		if (!dev_replace->tgtdev &&

		    !btrfs_test_opt(fs_info, DEGRADED)) {

		if (unlikely(!dev_replace->tgtdev && !btrfs_test_opt(fs_info, DEGRADED))) {

			ret = -EIO;

			btrfs_warn(fs_info,

			   "cannot mount because device replace operation is ongoing and");

fs/btrfs/disk-io.c

+12 −12
Original line number Diff line number Diff line
@@ -370,21 +370,21 @@ int btrfs_validate_extent_buffer(struct extent_buffer *eb, 
	ASSERT(check);



	found_start = btrfs_header_bytenr(eb);

	if (found_start != eb->start) {

	if (unlikely(found_start != eb->start)) {

		btrfs_err_rl(fs_info,

			"bad tree block start, mirror %u want %llu have %llu",

			     eb->read_mirror, eb->start, found_start);

		ret = -EIO;

		goto out;

	}

	if (check_tree_block_fsid(eb)) {

	if (unlikely(check_tree_block_fsid(eb))) {

		btrfs_err_rl(fs_info, "bad fsid on logical %llu mirror %u",

			     eb->start, eb->read_mirror);

		ret = -EIO;

		goto out;

	}

	found_level = btrfs_header_level(eb);

	if (found_level >= BTRFS_MAX_LEVEL) {

	if (unlikely(found_level >= BTRFS_MAX_LEVEL)) {

		btrfs_err(fs_info,

			"bad tree block level, mirror %u level %d on logical %llu",

			eb->read_mirror, btrfs_header_level(eb), eb->start);
@@ -410,7 +410,7 @@ int btrfs_validate_extent_buffer(struct extent_buffer *eb, 
		}

	}



	if (found_level != check->level) {

	if (unlikely(found_level != check->level)) {

		btrfs_err(fs_info,

		"level verify failed on logical %llu mirror %u wanted %u found %u",

			  eb->start, eb->read_mirror, check->level, found_level);
@@ -1046,7 +1046,7 @@ static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root, 
		root->node = NULL;

		goto fail;

	}

	if (!btrfs_buffer_uptodate(root->node, generation, false)) {

	if (unlikely(!btrfs_buffer_uptodate(root->node, generation, false))) {

		ret = -EIO;

		goto fail;

	}
@@ -2058,7 +2058,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info, 
	u64 bytenr = btrfs_super_log_root(disk_super);

	int level = btrfs_super_log_root_level(disk_super);



	if (fs_devices->rw_devices == 0) {

	if (unlikely(fs_devices->rw_devices == 0)) {

		btrfs_warn(fs_info, "log replay required on RO media");

		return -EIO;

	}
@@ -2079,7 +2079,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info, 
		btrfs_put_root(log_tree_root);

		return ret;

	}

	if (!extent_buffer_uptodate(log_tree_root->node)) {

	if (unlikely(!extent_buffer_uptodate(log_tree_root->node))) {

		btrfs_err(fs_info, "failed to read log tree");

		btrfs_put_root(log_tree_root);

		return -EIO;
@@ -2641,7 +2641,7 @@ static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int lev 
		root->node = NULL;

		return ret;

	}

	if (!extent_buffer_uptodate(root->node)) {

	if (unlikely(!extent_buffer_uptodate(root->node))) {

		free_extent_buffer(root->node);

		root->node = NULL;

		return -EIO;
@@ -3469,7 +3469,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	 * below in btrfs_init_dev_replace().

	 */

	btrfs_free_extra_devids(fs_devices);

	if (!fs_devices->latest_dev->bdev) {

	if (unlikely(!fs_devices->latest_dev->bdev)) {

		btrfs_err(fs_info, "failed to read devices");

		ret = -EIO;

		goto fail_tree_roots;
@@ -3963,7 +3963,7 @@ static int barrier_all_devices(struct btrfs_fs_info *info) 
	 * Checks last_flush_error of disks in order to determine the device

	 * state.

	 */

	if (errors_wait && !btrfs_check_rw_degradable(info, NULL))

	if (unlikely(errors_wait && !btrfs_check_rw_degradable(info, NULL)))

		return -EIO;



	return 0;
@@ -4076,7 +4076,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) 
		if (ret)

			total_errors++;

	}

	if (total_errors > max_errors) {

	if (unlikely(total_errors > max_errors)) {

		btrfs_err(fs_info, "%d errors while writing supers",

			  total_errors);

		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
@@ -4101,7 +4101,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) 
			total_errors++;

	}

	mutex_unlock(&fs_info->fs_devices->device_list_mutex);

	if (total_errors > max_errors) {

	if (unlikely(total_errors > max_errors)) {

		btrfs_handle_fs_error(fs_info, -EIO,

				      "%d errors while writing supers",

				      total_errors);