Commit 67710892 authored by Filipe Manana's avatar Filipe Manana
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Btrfs: be more precise on errors when getting an inode from disk 



When we attempt to read an inode from disk, we end up always returning an
-ESTALE error to the caller regardless of the actual failure reason, which
can be an out of memory problem (when allocating a path), some error found
when reading from the fs/subvolume btree (like a genuine IO error) or the
inode does not exists. So lets start returning the real error code to the
callers so that they don't treat all -ESTALE errors as meaning that the
inode does not exists (such as during orphan cleanup). This will also be
needed for a subsequent patch in the same series dealing with a special
fsync case.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
parent 95155585

fs/btrfs/inode.c

+18 −9
Original line number Diff line number Diff line
@@ -3428,10 +3428,10 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) 
		found_key.offset = 0;

		inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);

		ret = PTR_ERR_OR_ZERO(inode);

		if (ret && ret != -ESTALE)

		if (ret && ret != -ENOENT)

			goto out;



		if (ret == -ESTALE && root == root->fs_info->tree_root) {

		if (ret == -ENOENT && root == root->fs_info->tree_root) {

			struct btrfs_root *dead_root;

			struct btrfs_fs_info *fs_info = root->fs_info;

			int is_dead_root = 0;
@@ -3467,7 +3467,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) 
		 * Inode is already gone but the orphan item is still there,

		 * kill the orphan item.

		 */

		if (ret == -ESTALE) {

		if (ret == -ENOENT) {

			trans = btrfs_start_transaction(root, 1);

			if (IS_ERR(trans)) {

				ret = PTR_ERR(trans);
@@ -3626,7 +3626,7 @@ static noinline int acls_after_inode_item(struct extent_buffer *leaf, 
/*

 * read an inode from the btree into the in-memory inode

 */

static void btrfs_read_locked_inode(struct inode *inode)

static int btrfs_read_locked_inode(struct inode *inode)

{

	struct btrfs_path *path;

	struct extent_buffer *leaf;
@@ -3645,14 +3645,19 @@ static void btrfs_read_locked_inode(struct inode *inode) 
		filled = true;



	path = btrfs_alloc_path();

	if (!path)

	if (!path) {

		ret = -ENOMEM;

		goto make_bad;

	}



	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));



	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);

	if (ret)

	if (ret) {

		if (ret > 0)

			ret = -ENOENT;

		goto make_bad;

	}



	leaf = path->nodes[0];
@@ -3805,11 +3810,12 @@ cache_acl: 
	}



	btrfs_update_iflags(inode);

	return;

	return 0;



make_bad:

	btrfs_free_path(path);

	make_bad_inode(inode);

	return ret;

}



/*
@@ -5595,7 +5601,9 @@ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 
		return ERR_PTR(-ENOMEM);



	if (inode->i_state & I_NEW) {

		btrfs_read_locked_inode(inode);

		int ret;



		ret = btrfs_read_locked_inode(inode);

		if (!is_bad_inode(inode)) {

			inode_tree_add(inode);

			unlock_new_inode(inode);
@@ -5604,7 +5612,8 @@ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 
		} else {

			unlock_new_inode(inode);

			iput(inode);

			inode = ERR_PTR(-ESTALE);

			ASSERT(ret < 0);

			inode = ERR_PTR(ret < 0 ? ret : -ESTALE);

		}

	}

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