From 7af2ae1b1531feab5d38ec9c8f472dc6cceb4606 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 19 Apr 2024 20:36:11 +0800 Subject: [PATCH] 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: 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 Signed-off-by: Baokun Li Reviewed-by: Jingbo Xu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20240419123611.947084-3-libaokun1@huawei.com Signed-off-by: Gao Xiang --- 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);