Mailing List Archive

From: Christian Brauner <brauner@kernel.org>

When erofs_kill_sb() is called in block dev based mode, s_bdev may not
have been initialised yet, and if CONFIG_EROFS_FS_ONDEMAND is enabled,
it will be mistaken for fscache mode, and then attempt to free an anon_dev
that has never been allocated, triggering the following warning:

============================================
ida_free called for id=0 which is not allocated.
WARNING: CPU: 14 PID: 926 at lib/idr.c:525 ida_free+0x134/0x140
Modules linked in:
CPU: 14 PID: 926 Comm: mount Not tainted 6.9.0-rc3-dirty #630
RIP: 0010:ida_free+0x134/0x140
Call Trace:
<TASK>
erofs_kill_sb+0x81/0x90
deactivate_locked_super+0x35/0x80
get_tree_bdev+0x136/0x1e0
vfs_get_tree+0x2c/0xf0
do_new_mount+0x190/0x2f0
[...]
============================================

Now when erofs_kill_sb() is called, erofs_sb_info must have been
initialised, so use sbi->fsid to distinguish between the two modes.

Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
---
fs/erofs/super.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 21faa49bc970..30b49b2eee53 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -789,17 +789,13 @@ static int erofs_init_fs_context(struct fs_context *fc)

static void erofs_kill_sb(struct super_block *sb)
{
- struct erofs_sb_info *sbi;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);

- if (erofs_is_fscache_mode(sb))
+ if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid)
kill_anon_super(sb);
else
kill_block_super(sb);

- sbi = EROFS_SB(sb);
- if (!sbi)
- return;
-
erofs_free_dev_context(sbi->devs);
fs_put_dax(sbi->dax_dev, NULL);
erofs_fscache_unregister_fs(sb);
--
2.31.1