Re: [PATCH RFC 1/2] errno.h: Export EFSCORRUPTED error number

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Apr 11, 2019 at 08:28:44AM +0800, Qu Wenruo wrote:
> 
> 
> On 2019/4/10 下午11:11,  Darrick J. Wong  wrote:
> > On Wed, Apr 10, 2019 at 04:35:07PM +0800, Qu Wenruo wrote:
> >> Xfs and Ext* uses EFSCORRUPTED to indicate filesystem corruption.
> >> They both map EFSCORRUPTED to EUCLEAN.
> >>
> >> Btrfs/Ubifs/fscrypto all use EUCLEAN directly to indicate filesystem
> >> corruption.
> > 
> > I don't know if you (btrfs folks specifically) care but ext* and xfs
> > also use EFSBADCRC to signal unrecovered checksum validation failures.
> > Can we promote both of them to asm-generic/errno.h at the same time?
> 
> It looks pretty good to me in fact.
> 
> I'm really tired of using -EIO for csum mismatch/any other higher level
> mismatch.
> 
> The only concern is the "CRC" part. Yes, btrfs uses and only supports
> CRC32 so far, but I'm sure btrfs will support cryptographic hash.
> 
> So what about renaming it to EFSBADCSUM?

We've been shipping EFSBADCRC in xfslibs-dev userspace libraries for
years now, so we can't change the symbol name.

--D

> Thanks,
> Qu
> 
> > 
> > #define EFSBADCRC   EBADMSG
> > 
> > --D
> > 
> >> And block layer is going to distinguish filesystem corruption with
> >> oridinary EIO error, it's a good idea to export the initial EFSCORRUPTED
> >> declaration to <linux/errno.h> so all filesystems and block layer can
> >> take advantage of this easier-to-read error number.
> >>
> >> Signed-off-by: Qu Wenruo <wqu@suse.com>
> >> ---
> >>  fs/ext2/ext2.h                   | 1 -
> >>  fs/ext4/ext4.h                   | 1 -
> >>  fs/xfs/xfs_linux.h               | 1 -
> >>  include/uapi/asm-generic/errno.h | 3 +++
> >>  4 files changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
> >> index 10ab238de9a6..03d0ca8fae42 100644
> >> --- a/fs/ext2/ext2.h
> >> +++ b/fs/ext2/ext2.h
> >> @@ -369,7 +369,6 @@ struct ext2_inode {
> >>   */
> >>  #define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
> >>  #define	EXT2_ERROR_FS			0x0002	/* Errors detected */
> >> -#define	EFSCORRUPTED			EUCLEAN	/* Filesystem is corrupted */
> >>  
> >>  /*
> >>   * Mount flags
> >> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> >> index 82ffdacdc7fa..f906b5cbf96d 100644
> >> --- a/fs/ext4/ext4.h
> >> +++ b/fs/ext4/ext4.h
> >> @@ -3248,6 +3248,5 @@ extern const struct iomap_ops ext4_iomap_ops;
> >>  #endif	/* __KERNEL__ */
> >>  
> >>  #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
> >> -#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
> >>  
> >>  #endif	/* _EXT4_H */
> >> diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
> >> index edbd5a210df2..36e5c6549f15 100644
> >> --- a/fs/xfs/xfs_linux.h
> >> +++ b/fs/xfs/xfs_linux.h
> >> @@ -125,7 +125,6 @@ typedef __u32			xfs_nlink_t;
> >>  
> >>  #define ENOATTR		ENODATA		/* Attribute not found */
> >>  #define EWRONGFS	EINVAL		/* Mount with wrong filesystem type */
> >> -#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
> >>  #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
> >>  
> >>  #define SYNCHRONIZE()	barrier()
> >> diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
> >> index cf9c51ac49f9..ebd6e7e76a98 100644
> >> --- a/include/uapi/asm-generic/errno.h
> >> +++ b/include/uapi/asm-generic/errno.h
> >> @@ -98,6 +98,9 @@
> >>  #define	EINPROGRESS	115	/* Operation now in progress */
> >>  #define	ESTALE		116	/* Stale file handle */
> >>  #define	EUCLEAN		117	/* Structure needs cleaning */
> >> +
> >> +#define EFSCORRUPTED	EUCLEAN	/* Filesystem is corrupted */
> >> +
> >>  #define	ENOTNAM		118	/* Not a XENIX named type file */
> >>  #define	ENAVAIL		119	/* No XENIX semaphores available */
> >>  #define	EISNAM		120	/* Is a named type file */
> >> -- 
> >> 2.21.0
> >>
> > 
>