From: Christian Brauner brauner@kernel.org

commit 7af2ae1b1531feab5d38ec9c8f472dc6cceb4606 upstream.

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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Xiangyu Chen xiangyu.chen@windriver.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 25cd66e487e8..5bb194558da5 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -892,7 +892,7 @@ 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);

WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);

@@ -902,15 +902,11 @@ static void erofs_kill_sb(struct super_block *sb) return; }

- 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);