[v3] erofs: reliably distinguish block based and fscache mode

[PATCH -next v3 2/2] erofs: reliably distinguish block based and fscache mode

Posted by Baokun Li 1 year, 9 months ago

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

Re: [PATCH -next v3 2/2] erofs: reliably distinguish block based and fscache mode

Posted by Chao Yu 1 year, 9 months ago

On 2024/4/19 20:36, Baokun Li wrote:
> 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>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

Re: [PATCH -next v3 2/2] erofs: reliably distinguish block based and fscache mode

Posted by Gao Xiang 1 year, 9 months ago


On 2024/4/19 20:36, Baokun Li wrote:
> 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>

Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Thanks,
Gao Xiang

Re: [PATCH -next v3 2/2] erofs: reliably distinguish block based and fscache mode

Posted by Jingbo Xu 1 year, 9 months ago


On 4/19/24 8:36 PM, Baokun Li wrote:
> 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>

Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.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);

-- 
Thanks,
Jingbo