At the moment, xfs_alloc_fix_freelist() uses a mix of per-ag based
access and agf buffer based access to freelist and space usage
information. However, once the AGF buffer is locked inside this
function, it is guaranteed that both the in-memory and on-disk
values are identical. xfs_alloc_fix_freelist() doesn't modify the
values in the structures directly, so it is a read-only user of the
infomration, and hence can use the per-ag structure exclusively for
determining what it should do.
This opens up an avenue for cleaning up a lot of duplicated logic
whose only difference is the structure it gets the data from, and in
doing so removes a lot of needless byte swapping overhead when
fixing up the free list.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Test generic/224 is failing with a corruption being detected on one
of Michael's test boxes. Debug that Michael added is indicating
that the minleft trimming is resulting in an underflow:
.....
before fixup: rlen 1 args->len 0
after xfs_alloc_fix_len : rlen 1 args->len 1
before goto out_nominleft: rlen 1 args->len 0
before fixup: rlen 1 args->len 0
after xfs_alloc_fix_len : rlen 1 args->len 1
after fixup: rlen 1 args->len 1
before fixup: rlen 1 args->len 0
after xfs_alloc_fix_len : rlen 1 args->len 1
after fixup: rlen 4294967295 args->len 4294967295
XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_alloc.c, line: 1424
The "goto out_nominleft:" indicates that we are getting close to
ENOSPC in the AG, and a couple of allocations later we underflow
and the corruption check fires in xfs_alloc_ag_vextent_size().
The issue is that the extent length fixups comaprisons are done
with variables of xfs_extlen_t types. These are unsigned so an
underflow looks like a really big value and hence is not detected
as being smaller than the minimum length allowed for the extent.
Hence the corruption check fires as it is noticing that the returned
length is longer than the original extent length passed in.
This can be easily fixed by ensuring we do the underflow test on
signed values, the same way xfs_alloc_fix_len() prevents underflow.
So we realise in future that these casts prevent underflows from
going undetected, add comments to the code indicating this.
Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Tested-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Today, if we hit an XFS_WANT_CORRUPTED_RETURN we don't print any
information about which filesystem hit it. Passing in the mp allows
us to print the filesystem (device) name, which is a pretty critical
piece of information.
Tested by running fsfuzzer 'til I hit some.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Today, if we hit an XFS_WANT_CORRUPTED_GOTO we don't print any
information about which filesystem hit it. Passing in the mp allows
us to print the filesystem (device) name, which is a pretty critical
piece of information.
Tested by running fsfuzzer 'til I hit some.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
More on-disk format consolidation. A few declarations that weren't on-disk
format related move into better suitable spots.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
These were exposed by fsfuzzer runs; without them we fail
in various exciting and sometimes convoluted ways when we
encounter disk corruption.
Without the MAXLEVELS tests we tend to walk off the end of
an array in a loop like this:
for (i = 0; i < cur->bc_nlevels; i++) {
if (cur->bc_bufs[i])
Without the dirblklog test we try to allocate more memory
than we could possibly hope for and loop forever:
xfs_dabuf_map()
nfsb = mp->m_dir_geo->fsbcount;
irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP...
As for the logbsize check, that's the convoluted one.
If logbsize is specified at mount time, it's sanitized
in xfs_parseargs; in particular it makes sure that it's
not > XLOG_MAX_RECORD_BSIZE.
If not specified at mount time, it comes from the superblock
via sb_logsunit; this is limited to 256k at mkfs time as well;
it's copied into m_logbsize in xfs_finish_flags().
However, if for some reason the on-disk value is corrupt and
too large, nothing catches it. It's a circuitous path, but
that size eventually finds its way to places that make the kernel
very unhappy, leading to oopses in xlog_pack_data() because we
use the size as an index into iclog->ic_data, but the array
is not necessarily that big.
Anyway - bounds checking when we read from disk is a good thing!
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Convert all the errors the core XFs code to negative error signs
like the rest of the kernel and remove all the sign conversion we
do in the interface layers.
Errors for conversion (and comparison) found via searches like:
$ git grep " E" fs/xfs
$ git grep "return E" fs/xfs
$ git grep " E[A-Z].*;$" fs/xfs
Negation points found via searches like:
$ git grep "= -[a-z,A-Z]" fs/xfs
$ git grep "return -[a-z,A-D,F-Z]" fs/xfs
$ git grep " -[a-z].*;" fs/xfs
[ with some bits I missed from Brian Foster ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Move all the source files that are shared with userspace into
libxfs/. This is done as one big chunk simpy to get it done
quickly
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
