Btrfs: fix up read_tree_block to return proper error
The return value of read_tree_block() can confuse callers as it always
returns NULL for either -ENOMEM or -EIO, so it's likely that callers
parse it to a wrong error, for instance, in btrfs_read_tree_root().
This fixes the above issue.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 74b24b0..827951f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1847,8 +1847,10 @@
}
eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
- if (!eb || !extent_buffer_uptodate(eb)) {
- ret = (!eb) ? -ENOMEM : -EIO;
+ if (IS_ERR(eb)) {
+ ret = PTR_ERR(eb);
+ } else if (!extent_buffer_uptodate(eb)) {
+ ret = -EIO;
free_extent_buffer(eb);
break;
}
@@ -2002,7 +2004,9 @@
bytenr = btrfs_node_blockptr(eb, path->slots[i]);
eb = read_tree_block(root, bytenr, ptr_gen);
- if (!eb || !extent_buffer_uptodate(eb)) {
+ if (IS_ERR(eb)) {
+ return PTR_ERR(eb);
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
return -EIO;
}
@@ -2710,7 +2714,10 @@
blocksize = root->nodesize;
generation = btrfs_node_ptr_generation(upper->eb, slot);
eb = read_tree_block(root, bytenr, generation);
- if (!eb || !extent_buffer_uptodate(eb)) {
+ if (IS_ERR(eb)) {
+ err = PTR_ERR(eb);
+ goto next;
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
err = -EIO;
goto next;
@@ -2873,7 +2880,9 @@
BUG_ON(block->key_ready);
eb = read_tree_block(rc->extent_root, block->bytenr,
block->key.offset);
- if (!eb || !extent_buffer_uptodate(eb)) {
+ if (IS_ERR(eb)) {
+ return PTR_ERR(eb);
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
return -EIO;
}