Eric, Do you know what the status is of your XFS patch to make it work on ARM (old ABI)?
* Martin Michlmayr <[EMAIL PROTECTED]> [2008-03-17 09:50]: > A patch for this problem has been posted now. > > Message-ID: <[EMAIL PROTECTED]> > Date: Fri, 14 Mar 2008 22:24:49 -0500 > From: Eric Sandeen <[EMAIL PROTECTED]> > User-Agent: Thunderbird 2.0.0.12 (Macintosh/20080213) > MIME-Version: 1.0 > To: xfs-oss <[EMAIL PROTECTED]> > CC: [EMAIL PROTECTED] > Subject: [PATCH] fix dir2 shortform structures on ARM old ABI > > This should fix the longstanding issues with xfs and old ABI > arm boxes, which lead to various asserts and xfs shutdowns, > and for which an (incorrect) patch has been floating around > for years. (Said patch made ARM internally consistent, but > altered the normal xfs on-disk format such that it looked > corrupted on other architectures): > http://lists.arm.linux.org.uk/lurker/message/20040311.002034.5ecf21a2.html > > Old ABI ARM has interesting packing & padding; for example > on ARM old abi: > > struct xfs_dir2_sf_entry { > __uint8_t namelen; /* 0 1 */ > > /* XXX 3 bytes hole, try to pack */ > > xfs_dir2_sf_off_t offset; /* 4 4 */ > __uint8_t name[1]; /* 8 1 */ > > /* XXX 3 bytes hole, try to pack */ > > xfs_dir2_inou_t inumber; /* 12 8 */ > > /* size: 20, cachelines: 1 */ > /* sum members: 14, holes: 2, sum holes: 6 */ > /* last cacheline: 20 bytes */ > }; > > but on x86: > > struct xfs_dir2_sf_entry { > __uint8_t namelen; /* 0 1 */ > xfs_dir2_sf_off_t offset; /* 1 2 */ > __uint8_t name[1]; /* 3 1 */ > xfs_dir2_inou_t inumber; /* 4 8 */ > > /* size: 12, cachelines: 1 */ > /* last cacheline: 12 bytes */ > }; > > ... this sort of discrepancy leads to problems. > > I've verified this patch by comparing the on-disk structure > layouts using pahole from the dwarves package, as well as > running through a bit of xfsqa under qemu-arm, modified so > that the check/repair phase after each test actually executes > check/repair from the x86 host, on the filesystem populated > by the arm emulator. Thus far it all looks good. > > There are 2 other structures with extra padding at the end, > but they don't seem to cause trouble. I suppose they could > be packed as well: xfs_dir2_data_unused_t and xfs_dir2_sf_t. > > Note that userspace needs a similar treatment, and any > filesystems which were running with the previous rogue > "fix" will now see corruption (either in the kernel, or > during xfs_repair) with this fix properly in place; it > may be worth teaching xfs_repair to identify and fix that > specific issue. > > Signed-off-by: Eric Sandeen <[EMAIL PROTECTED]> > > --- > > Index: linux-2.6.24/fs/xfs/linux-2.6/xfs_linux.h > =================================================================== > --- linux-2.6.24.orig/fs/xfs/linux-2.6/xfs_linux.h > +++ linux-2.6.24/fs/xfs/linux-2.6/xfs_linux.h > @@ -300,4 +300,11 @@ static inline __uint64_t howmany_64(__ui > return x; > } > > +/* ARM old ABI has some weird alignment/padding */ > +#if defined(__arm__) && !defined(__ARM_EABI__) > +#define __arch_pack __attribute__((packed)) > +#else > +#define __arch_pack > +#endif > + > #endif /* __XFS_LINUX__ */ > Index: linux-2.6.24/fs/xfs/xfs_dir2_sf.h > =================================================================== > --- linux-2.6.24.orig/fs/xfs/xfs_dir2_sf.h > +++ linux-2.6.24/fs/xfs/xfs_dir2_sf.h > @@ -62,7 +62,7 @@ typedef union { > * Normalized offset (in a data block) of the entry, really > xfs_dir2_data_off_t. > * Only need 16 bits, this is the byte offset into the single block form. > */ > -typedef struct { __uint8_t i[2]; } xfs_dir2_sf_off_t; > +typedef struct { __uint8_t i[2]; } __arch_pack xfs_dir2_sf_off_t; > > /* > * The parent directory has a dedicated field, and the self-pointer must > @@ -76,14 +76,14 @@ typedef struct xfs_dir2_sf_hdr { > __uint8_t count; /* count of entries */ > __uint8_t i8count; /* count of 8-byte inode #s */ > xfs_dir2_inou_t parent; /* parent dir inode number */ > -} xfs_dir2_sf_hdr_t; > +} __arch_pack xfs_dir2_sf_hdr_t; > > typedef struct xfs_dir2_sf_entry { > __uint8_t namelen; /* actual name length */ > xfs_dir2_sf_off_t offset; /* saved offset */ > __uint8_t name[1]; /* name, variable size */ > xfs_dir2_inou_t inumber; /* inode number, var. offset */ > -} xfs_dir2_sf_entry_t; > +} __arch_pack xfs_dir2_sf_entry_t; > > typedef struct xfs_dir2_sf { > xfs_dir2_sf_hdr_t hdr; /* shortform header */ > > -- > Martin Michlmayr > http://www.cyrius.com/ > -- Martin Michlmayr http://www.cyrius.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
