erofs: reliably distinguish block based and fscache mode

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>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20240419123611.947084-3-libaokun1@huawei.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Christian Brauner 2024-04-19 20:36:11 +08:00 committed by Gao Xiang
parent 07abe43a28
commit 7af2ae1b15
1 changed files with 2 additions and 6 deletions

View File

@ -789,17 +789,13 @@ static int erofs_init_fs_context(struct fs_context *fc)
static void erofs_kill_sb(struct super_block *sb) 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); kill_anon_super(sb);
else else
kill_block_super(sb); kill_block_super(sb);
sbi = EROFS_SB(sb);
if (!sbi)
return;
erofs_free_dev_context(sbi->devs); erofs_free_dev_context(sbi->devs);
fs_put_dax(sbi->dax_dev, NULL); fs_put_dax(sbi->dax_dev, NULL);
erofs_fscache_unregister_fs(sb); erofs_fscache_unregister_fs(sb);