From 76bf149cd0298544631e756670b89c399c7acbca Mon Sep 17 00:00:00 2001 From: Daniel Linjama Date: Wed, 16 Sep 2026 09:15:56 +0300 Subject: [PATCH] btrfs: handle lack of space when cleaning up verity items When enable_verity() hits the qgroup limit, rollback_verity() needs its own metadata reservation. When the qgroup limit or lack of space refuses the rollback, the whole filesystem is forced read-only even though the qgroup limit was for one subvolume only. Also orphan cleanup at the next mount fails the same way, so the leftover items are never removed: with -EDQUOT the subvolume stays unreachable, and with -ENOSPC on a full filesystem the next read-write mount fails. Start transactions with btrfs_start_transaction_fallback_global_rsv() in btrfs_orphan_cleanup(), drop_verity_items() and rollback_verity(). Those calls only delete items and free the space in the end, so they may use the global reserve and skip the qgroup limit, which avoids -ENOSPC and -EDQUOT. Fixes: 146054090b08 ("btrfs: initial fsverity support") Reviewed-by: Qu Wenruo Signed-off-by: Daniel Linjama Signed-off-by: David Sterba --- fs/btrfs/inode.c | 3 ++- fs/btrfs/verity.c | 18 ++++++++++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4f976b52996d..e97446fc9e10 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3892,7 +3892,8 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) if (ret) goto out; } - trans = btrfs_start_transaction(root, 1); + /* Only deletes the orphan. */ + trans = btrfs_start_transaction_fallback_global_rsv(root, 1); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out; diff --git a/fs/btrfs/verity.c b/fs/btrfs/verity.c index 4e0ab5842274..600337a84fbe 100644 --- a/fs/btrfs/verity.c +++ b/fs/btrfs/verity.c @@ -93,6 +93,20 @@ static loff_t merkle_file_pos(const struct inode *inode) return rounded; } +/* + * Start a transaction for removing verity items or the verity orphan. + * + * Like unlink, this only deletes items and frees space in the end, so the + * reservation may come from the global reserve when the filesystem is full + * (-ENOSPC) and is not subject to the qgroup limit (-EDQUOT). Otherwise a + * failed enable could never be cleaned up in either situation. + */ +static struct btrfs_trans_handle *start_verity_cleanup_trans(struct btrfs_root *root, + unsigned int num_items) +{ + return btrfs_start_transaction_fallback_global_rsv(root, num_items); +} + /* * Drop all the items for this inode with this key_type. * @@ -120,7 +134,7 @@ static int drop_verity_items(struct btrfs_inode *inode, u8 key_type) while (1) { /* 1 for the item being dropped */ - trans = btrfs_start_transaction(root, 1); + trans = start_verity_cleanup_trans(root, 1); if (IS_ERR(trans)) return PTR_ERR(trans); @@ -466,7 +480,7 @@ static int rollback_verity(struct btrfs_inode *inode) * 1 for updating the inode flag * 1 for deleting the orphan */ - trans = btrfs_start_transaction(root, 2); + trans = start_verity_cleanup_trans(root, 2); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL;