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: Filipe Manana <fdmanana@suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3e61bd1..f968654 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3428,10 +3428,10 @@
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 @@
* 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 @@
/*
* 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 @@
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 @@
}
btrfs_update_iflags(inode);
- return;
+ return 0;
make_bad:
btrfs_free_path(path);
make_bad_inode(inode);
+ return ret;
}
/*
@@ -5595,7 +5601,9 @@
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 @@
} else {
unlock_new_inode(inode);
iput(inode);
- inode = ERR_PTR(-ESTALE);
+ ASSERT(ret < 0);
+ inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
}
}