On 6/7/18 8:23 PM, Darrick J. Wong wrote: > On Fri, Jun 08, 2018 at 11:10:39AM +1000, Dave Chinner wrote: >> On Thu, Jun 07, 2018 at 09:16:31AM -0700, Darrick J. Wong wrote: >>> On Tue, Jun 05, 2018 at 10:10:15AM -0700, Darrick J. Wong wrote: >>>> On Tue, Jun 05, 2018 at 04:24:19PM +1000, Dave Chinner wrote: >>>>> From: Dave Chinner <dchinner@xxxxxxxxxx> >>>>> >>>>> There are rules for vald extent size hints. We enforce them when >>>>> applications set them, but fuzzers violate those rules and that >>>>> screws us over. >>>>> >>>>> This results in alignment assertion failures when setting up >>>>> allocations such as this in direct IO: >>>>> >>>>> XFS: Assertion failed: ap->length, file: fs/xfs/libxfs/xfs_bmap.c, line: 3432 >>>>> .... >>>>> Call Trace: >>>>> xfs_bmap_btalloc+0x415/0x910 >>>>> xfs_bmapi_write+0x71c/0x12e0 >>>>> xfs_iomap_write_direct+0x2a9/0x420 >>>>> xfs_file_iomap_begin+0x4dc/0xa70 >>>>> iomap_apply+0x43/0x100 >>>>> iomap_file_buffered_write+0x62/0x90 >>>>> xfs_file_buffered_aio_write+0xba/0x300 >>>>> __vfs_write+0xd5/0x150 >>>>> vfs_write+0xb6/0x180 >>>>> ksys_write+0x45/0xa0 >>>>> do_syscall_64+0x5a/0x180 >>>>> entry_SYSCALL_64_after_hwframe+0x49/0xbe >>>>> >>>>> And from xfs_db: >>>>> >>>>> core.extsize = 10380288 >>>>> >>>>> Which is not an integer multiple of the block size, and so violates >>>>> Rule #7 for setting extent size hints. Validate extent size hint >>>>> rules in the inode verifier to catch this. >>>>> >>>>> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> >>>> >>>> Looks ok modulo my comments in the next patch, >>>> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> >>> >>> FWIW when I applied this to xfsprogs I saw an xfs/033 regression: >>> >>> Phase 6 - check inode connectivity... >>> reinitializing root directory >>> Metadata corruption detected at 0x5555555c60e0, inode 0x80 dinode >>> >>> fatal error -- could not iget root inode -- error - 117 >>> [Inferior 1 (process 1178) exited with code 01] >>> (gdb) l *(0x5555555c60e0) >>> 0x5555555c60e0 is in libxfs_inode_validate_extsize (xfs_inode_buf.c:729). >>> >>> We fail the inode verifier while trying to _iget the root inode so that >>> we can reinitialize it; I suspect phase 3 is going to need to check the >>> extent size hints and clear them. >> >> I'm actually quite happy to see that the continual process of >> hardening the kernel verifiers has got to the point where we are >> starting to expose deficiencies in xfs_repair. >> >> Can I wait for the xfsprogs libxfs-4.18-sync branch to pick up these >> verifier changes before looking at what repair needs to do to avoid >> it? I don't want to do a forced context switch to >> debugging/enhancing userspace code right at this moment.... > > That's ultimately up to Eric, but since fixing it is nontrivial surgery > on xfs_repair (and the verifier update patch doesn't itself break the > build) I'd be fine with fixing it after the 4.18 sync goes in. > > --D I think that getting it into the kernel and even into the xfsprogs/libxfs tree for 4.18 is fine as long as we are sure a repair fix will be forthcoming before 4.18 is done as long as it doesn't blow up regression testing /too/ much... This kernel<->libxfs<->application coordination can get a bit chicken-and-eggy sometimes. I guess this kernel change means that only a latest xfs_repair will make a latest kernel happy; I guess that's fairly normal. -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
