Re: [PATCH 1/7] btrfs-progs: check/lowmem: Add inode mode check

[Nikolay Borisov <nborisov@suse.com>]

On 25.03.19 г. 10:22 ч., Qu Wenruo wrote:
> There is one report about invalid free space cache inode mode.
> Normally free space cache inode should have mode 100600 (regular file,
> no uid/gid/sticky bit, rw------ bit).
> 
> But in that report, we have free space cache inode mode as 0.
> 
> So at least btrfs check should report invalid inode mode.
> 
> This patch will at least make btrfs check lowmem mode to detect this
> problem.
> 
> Please note that, this check only applies to inodes in fs/subvol trees.
> It doesn't apply to free space cache inodes.
> 
> Reported-by: Thorsten Hirsch <t.hirsch@web.de>
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  check/mode-common.h | 24 ++++++++++++++++++++++++
>  check/mode-lowmem.c |  5 +++++
>  check/mode-lowmem.h |  1 +
>  3 files changed, 30 insertions(+)
> 
> diff --git a/check/mode-common.h b/check/mode-common.h
> index 1fb3cda7d89d..4c88365abbcc 100644
> --- a/check/mode-common.h
> +++ b/check/mode-common.h
> @@ -126,4 +126,28 @@ int delete_corrupted_dir_item(struct btrfs_trans_handle *trans,
>  			      struct btrfs_key *di_key, char *namebuf,
>  			      u32 namelen);
>  
> +/*
> + * Check if the inode mode @imode is valid
> + *
> + * This check focuses on S_FTMT bits and unused bits.
> + * Sticky/setuid/setgid and regular owner/group/other bits won't cause
> + * any problem.
> + */
> +static inline bool is_valid_imode(u32 imode)
> +{
> +	if (imode & ~(S_IFMT | 07777))
> +		return false;
> +
> +	/*
> +	 * S_IFMT is not bitmap, nor pure numbering sequence. Need per valid
> +	 * number check.
> +	 */
> +	imode &= S_IFMT;
> +	if (imode != S_IFDIR && imode != S_IFCHR && imode != S_IFBLK &&
> +	    imode != S_IFREG && imode != S_IFIFO && imode != S_IFLNK &&
> +	    imode != S_IFSOCK)
> +		return false;
> +	return true;
> +}
> +
>  #endif
> diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
> index fc6228a05a1b..1553a4a5d2c1 100644
> --- a/check/mode-lowmem.c
> +++ b/check/mode-lowmem.c
> @@ -2452,6 +2452,11 @@ static int check_inode_item(struct btrfs_root *root, struct btrfs_path *path)
>  	nlink = btrfs_inode_nlink(node, ii);
>  	nodatasum = btrfs_inode_flags(node, ii) & BTRFS_INODE_NODATASUM;
>  
> +	if (!is_valid_imode(mode)) {
> +		error("invalid imode mode bits: 0%o", mode);
> +		err |= INODE_MODE_ERROR;
> +	}
> +
>  	if (S_ISLNK(mode) &&
>  	    flags & (BTRFS_INODE_IMMUTABLE | BTRFS_INODE_APPEND)) {
>  		err |= INODE_FLAGS_ERROR;
> diff --git a/check/mode-lowmem.h b/check/mode-lowmem.h
> index 46b9b191ce24..e0ab30b770d5 100644
> --- a/check/mode-lowmem.h
> +++ b/check/mode-lowmem.h
> @@ -46,6 +46,7 @@
>  #define FATAL_ERROR             (1<<22) /* Fatal bit for errno */
>  #define INODE_FLAGS_ERROR	(1<<23) /* Invalid inode flags */
>  #define DIR_ITEM_HASH_MISMATCH	(1<<24) /* Dir item hash mismatch */
> +#define INODE_MODE_ERROR	(1<<25) /* Bad inode mode */
>  
>  /*
>   * Error bit for low memory mode check.
>