The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e85fde5162bf1b242cbd6daf7dba0f9b457d592b Mon Sep 17 00:00:00 2001
From: Qu Wenruo wqu@suse.com Date: Fri, 24 Jul 2020 14:46:10 +0800 Subject: [PATCH] btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations
[BUG] When quota is enabled for TEST_DEV, generic/013 sometimes fails like this:
generic/013 14s ... _check_dmesg: something found in dmesg (see xfstests-dev/results//generic/013.dmesg)
And with the following metadata leak:
BTRFS warning (device dm-3): qgroup 0/1370 has unreleased space, type 2 rsv 49152 ------------[ cut here ]------------ WARNING: CPU: 2 PID: 47912 at fs/btrfs/disk-io.c:4078 close_ctree+0x1dc/0x323 [btrfs] Call Trace: btrfs_put_super+0x15/0x17 [btrfs] generic_shutdown_super+0x72/0x110 kill_anon_super+0x18/0x30 btrfs_kill_super+0x17/0x30 [btrfs] deactivate_locked_super+0x3b/0xa0 deactivate_super+0x40/0x50 cleanup_mnt+0x135/0x190 __cleanup_mnt+0x12/0x20 task_work_run+0x64/0xb0 __prepare_exit_to_usermode+0x1bc/0x1c0 __syscall_return_slowpath+0x47/0x230 do_syscall_64+0x64/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ---[ end trace a6cfd45ba80e4e06 ]--- BTRFS error (device dm-3): qgroup reserved space leaked BTRFS info (device dm-3): disk space caching is enabled BTRFS info (device dm-3): has skinny extents
[CAUSE] The qgroup preallocated meta rsv operations of that offending root are:
btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072 btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072 btrfs_subvolume_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=49152 btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072 btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072
It's pretty obvious that, we reserve qgroup meta rsv in btrfs_subvolume_reserve_metadata(), but doesn't have corresponding release/convert calls in btrfs_subvolume_release_metadata().
This leads to the leakage.
[FIX] To fix this bug, we should follow what we're doing in btrfs_delalloc_reserve_metadata(), where we reserve qgroup space, and add it to block_rsv->qgroup_rsv_reserved.
And free the qgroup reserved metadata space when releasing the block_rsv.
To do this, we need to change the btrfs_subvolume_release_metadata() to accept btrfs_root, and record the qgroup_to_release number, and call btrfs_qgroup_convert_reserved_meta() for it.
Fixes: 733e03a0b26a ("btrfs: qgroup: Split meta rsv type into meta_prealloc and meta_pertrans") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik josef@toxicpanda.com Signed-off-by: Qu Wenruo wqu@suse.com Signed-off-by: David Sterba dsterba@suse.com
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index eb7adc069926..f9d4e0958e2e 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2622,7 +2622,7 @@ enum btrfs_flush_state { int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, struct btrfs_block_rsv *rsv, int nitems, bool use_global_rsv); -void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info, +void btrfs_subvolume_release_metadata(struct btrfs_root *root, struct btrfs_block_rsv *rsv); void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a50a40f8bef2..123521aa5595 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4051,7 +4051,7 @@ int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry) err = ret; inode->i_flags |= S_DEAD; out_release: - btrfs_subvolume_release_metadata(fs_info, &block_rsv); + btrfs_subvolume_release_metadata(root, &block_rsv); out_up_write: up_write(&fs_info->subvol_sem); if (err) { diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index a5355a16eabb..3779a6c12184 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -618,7 +618,7 @@ static noinline int create_subvol(struct inode *dir, trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); - btrfs_subvolume_release_metadata(fs_info, &block_rsv); + btrfs_subvolume_release_metadata(root, &block_rsv); goto fail_free; } trans->block_rsv = &block_rsv; @@ -742,7 +742,7 @@ static noinline int create_subvol(struct inode *dir, kfree(root_item); trans->block_rsv = NULL; trans->bytes_reserved = 0; - btrfs_subvolume_release_metadata(fs_info, &block_rsv); + btrfs_subvolume_release_metadata(root, &block_rsv);
err = btrfs_commit_transaction(trans); if (err && !ret) @@ -856,7 +856,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, if (ret && pending_snapshot->snap) pending_snapshot->snap->anon_dev = 0; btrfs_put_root(pending_snapshot->snap); - btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv); + btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv); free_pending: if (pending_snapshot->anon_dev) free_anon_bdev(pending_snapshot->anon_dev); diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index c89697486366..702dc5441f03 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -512,11 +512,20 @@ int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, if (ret && qgroup_num_bytes) btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
+ if (!ret) { + spin_lock(&rsv->lock); + rsv->qgroup_rsv_reserved += qgroup_num_bytes; + spin_unlock(&rsv->lock); + } return ret; }
-void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info, +void btrfs_subvolume_release_metadata(struct btrfs_root *root, struct btrfs_block_rsv *rsv) { - btrfs_block_rsv_release(fs_info, rsv, (u64)-1, NULL); + struct btrfs_fs_info *fs_info = root->fs_info; + u64 qgroup_to_release; + + btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release); + btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release); }