diff mbox series

[16/21] btrfs: simplify check for extent item overrun at lookup_inline_extent_backref()

Message ID 1e6e5a365ce01567b0334ac2792c8e8aa1fe1a64.1694174371.git.fdmanana@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs: updates to delayed refs accounting and space reservation | expand

Commit Message

Filipe Manana Sept. 8, 2023, 12:09 p.m. UTC 
From: Filipe Manana <fdmanana@suse.com>

At lookup_inline_extent_backref() we can simplify the check for an overrun
of the extent item by making the while loop's condition to be "ptr < end"
and then check after the loop if an overrun happened ("ptr > end"). This
reduces indentation and makes the loop condition more clear. So move the
check out of the loop and change the loop condition accordingly, while
also adding the 'unlikely' tag to the check since it's not supposed to be
triggered.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/extent-tree.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

Comments

Josef Bacik Sept. 8, 2023, 3:11 p.m. UTC | #1 
On Fri, Sep 08, 2023 at 01:09:18PM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> At lookup_inline_extent_backref() we can simplify the check for an overrun
> of the extent item by making the while loop's condition to be "ptr < end"
> and then check after the loop if an overrun happened ("ptr > end"). This
> reduces indentation and makes the loop condition more clear. So move the
> check out of the loop and change the loop condition accordingly, while
> also adding the 'unlikely' tag to the check since it's not supposed to be
> triggered.
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef
diff mbox series

Patch

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 756589195ed7..b27e0a6878b3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -883,17 +883,7 @@  int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
 		needed = BTRFS_REF_TYPE_BLOCK;
 
 	ret = -ENOENT;
-	while (1) {
-		if (ptr >= end) {
-			if (ptr > end) {
-				ret = -EUCLEAN;
-				btrfs_print_leaf(path->nodes[0]);
-				btrfs_crit(fs_info,
-"overrun extent record at slot %d while looking for inline extent for root %llu owner %llu offset %llu parent %llu",
-					path->slots[0], root_objectid, owner, offset, parent);
-			}
-			break;
-		}
+	while (ptr < end) {
 		iref = (struct btrfs_extent_inline_ref *)ptr;
 		type = btrfs_get_extent_inline_ref_type(leaf, iref, needed);
 		if (type == BTRFS_REF_TYPE_INVALID) {
@@ -940,6 +930,16 @@  int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
 		}
 		ptr += btrfs_extent_inline_ref_size(type);
 	}
+
+	if (unlikely(ptr > end)) {
+		ret = -EUCLEAN;
+		btrfs_print_leaf(path->nodes[0]);
+		btrfs_crit(fs_info,
+"overrun extent record at slot %d while looking for inline extent for root %llu owner %llu offset %llu parent %llu",
+			   path->slots[0], root_objectid, owner, offset, parent);
+		goto out;
+	}
+
 	if (ret == -ENOENT && insert) {
 		if (item_size + extra_size >=
 		    BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {