diff options
| author | robbieko <robbieko@synology.com> | 2026-04-13 14:52:36 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2026-04-21 04:02:34 +0200 |
| commit | fe0cdfd7118d8b40a21bfac221bb4982c5e10e10 (patch) | |
| tree | ec9642f0a25558a4dc2a963d7e97985bf14046a5 /fs | |
| parent | 653361585d251fbca0e19ac58b04ba95dd01e378 (diff) | |
btrfs: handle -EAGAIN from btrfs_duplicate_item and refresh stale leaf pointer
In the 'punch a hole' case of btrfs_delete_raid_extent(),
btrfs_duplicate_item() can return -EAGAIN when the leaf needs to be
split and the path becomes invalid. The old code treats any error as
fatal and breaks out of the loop.
Additionally, btrfs_duplicate_item() may trigger setup_leaf_for_split()
which can reallocate the leaf node. The code continues using the old
leaf pointer, leading to use-after-free or stale data access.
Fix both issues by:
- Handling -EAGAIN specifically: release the path and retry the loop.
- Refreshing leaf = path->nodes[0] after successful duplication.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: robbieko <robbieko@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/raid-stripe-tree.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c index d454894b9e66..2e0d2f83c651 100644 --- a/fs/btrfs/raid-stripe-tree.c +++ b/fs/btrfs/raid-stripe-tree.c @@ -194,9 +194,19 @@ int btrfs_delete_raid_extent(struct btrfs_trans_handle *trans, u64 start, u64 le /* The "right" item. */ ret = btrfs_duplicate_item(trans, stripe_root, path, &newkey); + if (ret == -EAGAIN) { + btrfs_release_path(path); + continue; + } if (ret) break; + /* + * btrfs_duplicate_item() may have triggered a leaf + * split via setup_leaf_for_split(), so we must refresh + * our leaf pointer from the path. + */ + leaf = path->nodes[0]; item_size = btrfs_item_size(leaf, path->slots[0]); extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_stripe_extent); |