xfs: silence sparse warning when checking version number

Scrub checks the superblock version number against the known good
feature bits that can be set in the version mask. It calculates
the version mask to compare like so:

vernum_mask = cpu_to_be16(~XFS_SB_VERSION_OKBITS |
XFS_SB_VERSION_NUMBITS |
XFS_SB_VERSION_ALIGNBIT |
XFS_SB_VERSION_DALIGNBIT |
XFS_SB_VERSION_SHAREDBIT |
XFS_SB_VERSION_LOGV2BIT |
XFS_SB_VERSION_SECTORBIT |
XFS_SB_VERSION_EXTFLGBIT |
XFS_SB_VERSION_DIRV2BIT);

This generates a sparse warning:

fs/xfs/scrub/agheader.c:168:23: warning: cast truncates bits from constant value (ffff3f8f becomes 3f8f)

This is because '~XFS_SB_VERSION_OKBITS' is considered a 32 bit
constant, even though it's value is always under 16 bits.

This is a kinda silly thing to do, because:

/*
* Supported feature bit list is just all bits in the versionnum field because
* we've used them all up and understand them all. Except, of course, for the
* shared superblock bit, which nobody knows what it does and so is unsupported.
*/
#define XFS_SB_VERSION_OKBITS \
((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
~XFS_SB_VERSION_SHAREDBIT)

#define XFS_SB_VERSION_NUMBITS 0x000f
#define XFS_SB_VERSION_ALLFBITS 0xfff0
#define XFS_SB_VERSION_SHAREDBIT 0x0200

XFS_SB_VERSION_OKBITS has a value of 0xfdff, and so
~XFS_SB_VERSION_OKBITS == XFS_SB_VERSION_SHAREDBIT. The calculated
mask already sets XFS_SB_VERSION_SHAREDBIT, so starting with
~XFS_SB_VERSION_OKBITS is completely redundant....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

xfs: check AGI unlinked inode buckets

Look for corruptions in the AGI unlinked bucket chains.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: split the agf_roots and agf_levels arrays

Using arrays of largely unrelated fields that use the btree number
as index is not very robust. Split the arrays into three separate
fields instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: teach scrub to check for sole ownership of metadata objects

Strengthen online scrub's checking even further by enabling us to check
that a range of blocks are owned solely by a given owner.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: ensure that all metadata and data blocks are not cow staging extents

Make sure that all filesystem metadata blocks and file data blocks are
not also marked as CoW staging extents. The extra checking added here
was inspired by an actual VM host filesystem corruption incident due to
bugs in the CoW handling of 4.x kernels.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: minimize overhead of drain wakeups by using jump labels

To reduce the runtime overhead even further when online fsck isn't
running, use a static branch key to decide if we call wake_up on the
drain. For compilers that support jump labels, the call to wake_up is
replaced by a nop sled when nobody is waiting for intents to drain.

From my initial microbenchmarking, every transition of the static key
between the on and off states takes about 22000ns to complete; this is
paid entirely by the xfs_scrub process. When the static key is off
(which it should be when fsck isn't running), the nop sled adds an
overhead of approximately 0.36ns to runtime code. The post-atomic
lockless waiter check adds about 0.03ns, which is basically free.

For the few compilers that don't support jump labels, runtime code pays
the cost of calling wake_up on an empty waitqueue, which was observed to
be about 30ns. However, most architectures that have sufficient memory
and CPU capacity to run XFS also support jump labels, so this is not
much of a worry.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: update copyright years for scrub/ files

Update the copyright years in the scrub/ source code files. This isn't
required, but it's helpful to remind myself just how long it's taken to
develop this feature.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: fix author and spdx headers on scrub/ files

Fix the spdx tags to match current practice, and update the author
contact information.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: standardize GFP flags usage in online scrub

Memory allocation usage is the same throughout online fsck -- we want
kernel memory, we have to be able to back out if we can't allocate
memory, and we don't want to spray dmesg with memory allocation failure
reports. Standardize the GFP flag usage and document these requirements.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: don't track the AGFL buffer in the scrub AG context

While scrubbing an allocation group, we don't need to hold the AGFL
buffer as part of the scrub context. All that is necessary to lock an
AG is to hold the AGI and AGF buffers, so fix all the existing users of
the AGFL buffer to grab them only when necessary.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: Pre-calculate per-AG agino geometry

There is a lot of overhead in functions like xfs_verify_agino() that
repeatedly calculate the geometry limits of an AG. These can be
pre-calculated as they are static and the verification context has
a per-ag context it can quickly reference.

In the case of xfs_verify_agino(), we now always have a perag
context handy, so we can store the minimum and maximum agino values
in the AG in the perag. This means we don't have to calculate
it on every call and it can be inlined in callers if we move it
to xfs_ag.h.

xfs_verify_agino_or_null() gets the same perag treatment.

xfs_agino_range() is moved to xfs_ag.c as it's not really a type
function, and it's use is largely restricted as the first and last
aginos can be grabbed straight from the perag in most cases.

Note that we leave the original xfs_verify_agino in place in
xfs_types.c as a static function as other callers in that file do
not have per-ag contexts so still need to go the long way. It's been
renamed to xfs_verify_agno_agino() to indicate it takes both an agno
and an agino to differentiate it from new function.

$ size --totals fs/xfs/built-in.a
text data bss dec hex filename
before 1482185 329588 572 1812345 1ba779 (TOTALS)
after 1481937 329588 572 1812097 1ba681 (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: Pre-calculate per-AG agbno geometry

There is a lot of overhead in functions like xfs_verify_agbno() that
repeatedly calculate the geometry limits of an AG. These can be
pre-calculated as they are static and the verification context has
a per-ag context it can quickly reference.

In the case of xfs_verify_agbno(), we now always have a perag
context handy, so we can store the AG length and the minimum valid
block in the AG in the perag. This means we don't have to calculate
it on every call and it can be inlined in callers if we move it
to xfs_ag.h.

Move xfs_ag_block_count() to xfs_ag.c because it's really a
per-ag function and not an XFS type function. We need a little
bit of rework that is specific to xfs_initialise_perag() to allow
growfs to calculate the new perag sizes before we've updated the
primary superblock during the grow (chicken/egg situation).

Note that we leave the original xfs_verify_agbno in place in
xfs_types.c as a static function as other callers in that file do
not have per-ag contexts so still need to go the long way. It's been
renamed to xfs_verify_agno_agbno() to indicate it takes both an agno
and an agbno to differentiate it from new function.

Future commits will make similar changes for other per-ag geometry
validation functions.

Further:

$ size --totals fs/xfs/built-in.a
text data bss dec hex filename
before 1483006 329588 572 1813166 1baaae (TOTALS)
after 1482185 329588 572 1812345 1ba779 (TOTALS)

This rework reduces the binary size by ~820 bytes, indicating
that much less work is being done to bounds check the agbno values
against on per-ag geometry information.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: fix online fsck handling of v5 feature bits on secondary supers

While I was auditing the code in xfs_repair that adds feature bits to
existing V5 filesystems, I decided to have a look at how online fsck
handles feature bits, and I found a few problems:

1) ATTR2 is added to the primary super when an xattr is set to a file,
but that isn't consistently propagated to secondary supers. This isn't
a corruption, merely a discrepancy that repair will fix if it ever has
to restore the primary from a secondary. Hence, if we find a mismatch
on a secondary, this is a preen condition, not a corruption.

2) There are more compat and ro_compat features now than there used to
be, but we mask off the newer features from testing. This means we
ignore inconsistencies in the INOBTCOUNT and BIGTIME features, which is
wrong. Get rid of the masking and compare directly.

3) NEEDSREPAIR, when set on a secondary, is ignored by everyone. Hence
a mismatch here should also be flagged for preening, and online repair
should clear the flag. Right now we ignore it due to (2).

4) log_incompat features are ephemeral, since we can clear the feature
bit as soon as the log no longer contains live records for a particular
log feature. As such, the only copy we care about is the one in the
primary super. If we find any bits set in the secondary super, we
should flag that for preening, and clear the bits if the user elects to
repair it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: rename m_ag_maxlevels to m_allocbt_maxlevels

Years ago when XFS was thought to be much more simple, we introduced
m_ag_maxlevels to specify the maximum btree height of per-AG btrees for
a given filesystem mount. Then we observed that inode btrees don't
actually have the same height and split that off; and now we have rmap
and refcount btrees with much different geometries and separate
maxlevels variables.

The 'ag' part of the name doesn't make much sense anymore, so rename
this to m_alloc_maxlevels to reinforce that this is the maximum height
of the *free space* btrees. This sets us up for the next patch, which
will add a variable to track the maximum height of all AG btrees.

(Also take the opportunity to improve adjacent comments and fix minor
style problems.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: stricter btree height checking when looking for errors

Since each btree type has its own precomputed maxlevels variable now,
use them instead of the generic XFS_BTREE_MAXLEVELS to check the level
of each per-AG btree.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>

xfs: introduce xfs_sb_is_v5 helper

Rather than open coding XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5
checks everywhere, add a simple wrapper to encapsulate this and make
the code easier to read.

This allows us to remove the xfs_sb_version_has_v3inode() wrapper
which is only used in xfs_format.h now and is just a version number
check.

There are a couple of places where we should be checking the mount
feature bits rather than the superblock version (e.g. remount), so
those are converted to use xfs_has_crc(mp) instead.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: convert xfs_sb_version_has checks to use mount features

This is a conversion of the remaining xfs_sb_version_has..(sbp)
checks to use xfs_has_..(mp) feature checks.

This was largely done with a vim replacement macro that did:

:0,$s/xfs_sb_version_has\(.*\)&\(.*\)->m_sb/xfs_has_\1\2/g<CR>

A couple of other variants were also used, and the rest touched up
by hand.

$ size -t fs/xfs/built-in.a
text data bss dec hex filename
before 1127533 311352 484 1439369 15f689 (TOTALS)
after 1125360 311352 484 1437196 15ee0c (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: replace xfs_sb_version checks with feature flag checks

Convert the xfs_sb_version_hasfoo() to checks against
mp->m_features. Checks of the superblock itself during disk
operations (e.g. in the read/write verifiers and the to/from disk
formatters) are not converted - they operate purely on the
superblock state. Everything else should use the mount features.

Large parts of this conversion were done with sed with commands like
this:

for f in `git grep -l xfs_sb_version_has fs/xfs/*.c`; do
sed -i -e 's/xfs_sb_version_has\(.*\)(&\(.*\)->m_sb)/xfs_has_\1(\2)/' $f
done

With manual cleanups for things like "xfs_has_extflgbit" and other
little inconsistencies in naming.

The result is ia lot less typing to check features and an XFS binary
size reduced by a bit over 3kB:

$ size -t fs/xfs/built-in.a
text data bss dec hex filenam
before 1130866 311352 484 1442702 16038e (TOTALS)
after 1127727 311352 484 1439563 15f74b (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: make the record pointer passed to query_range functions const

The query_range functions are supposed to call a caller-supplied
function on each record found in the dataset. These functions don't
own the memory storing the record, so don't let them change the record.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: remove unnecessary agno variable from struct xchk_ag

Now that we always grab an active reference to a perag structure when
dealing with perag metadata, we can remove this unnecessary variable.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: grab active perag ref when reading AG headers

This patch prepares scrub to deal with the possibility of tearing down
entire AGs by changing the order of resource acquisition to match the
rest of the XFS codebase. In other words, scrub now grabs AG resources
in order of: perag structure, then AGI/AGF/AGFL buffers, then btree
cursors; and releases them in reverse order.

This requires us to distinguish xchk_ag_init callers -- some are
responding to a user request to check AG metadata, in which case we can
return ENOENT to userspace; but other callers have an ondisk reference
to an AG that they're trying to cross-reference. In this second case,
the lack of an AG means there's ondisk corruption, since ondisk metadata
cannot point into nonexistent space.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>

xfs: move xfs_perag_get/put to xfs_ag.[ch]

They are AG functions, not superblock functions, so move them to the
appropriate location.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fall through */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:

fs/xfs/libxfs/xfs_alloc.c:3167:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_da_btree.c:286:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:346:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:388:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_bmap_util.c:246:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:88:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:96:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_file.c:867:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:562:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:1548:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_iomap.c:1040:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_inode.c:852:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_log.c:2627:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_trans_buf.c:298:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/bmap.c:275:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/btree.c:48:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:85:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:138:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:698:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/dabtree.c:51:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/repair.c:951:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/agheader.c:89:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

xfs: don't check agf_btreeblks on pre-lazysbcount filesystems

The AGF free space btree block counter wasn't added until the
lazysbcount feature was added to XFS midway through the life of the V4
format, so ignore the field when checking. Online AGF repair requires
rmapbt, so it doesn't need the feature check.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: remove return value from xchk_ag_btcur_init

Functions called by this function cannot fail, so get rid of the return
and error checking.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: set the scrub AG number in xchk_ag_read_headers

Since xchk_ag_read_headers initializes fields in struct xchk_ag, we
might as well set the AG number and save the callers the trouble.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: support inode btree blockcounts in online scrub

Add the necessary bits to the online scrub code to check the inode btree
counters when enabled.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove XFS_BUF_TO_SBP

Just dereference bp->b_addr directly and make the code a little
simpler and more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: remove XFS_BUF_TO_AGF

Just dereference bp->b_addr directly and make the code a little
simpler and more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: remove XFS_BUF_TO_AGI

Just dereference bp->b_addr directly and make the code a little
simpler and more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: remove all *_ITER_ABORT values

Use -ECANCELED to signal "stop iterating" instead of these magical
*_ITER_ABORT values, since it's duplicative.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: create iterator error codes

Currently, xfs doesn't have generic error codes defined for "stop
iterating"; we just reuse the XFS_BTREE_QUERY_* return values. This
looks a little weird if we're not actually iterating a btree index.
Before we start adding more iterators, we should create general
XFS_ITER_{CONTINUE,ABORT} return values and define the XFS_BTREE_QUERY_*
ones from that.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove unused header files

There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.

nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this. I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: scrub should check incore counters against ondisk headers

In theory, the incore per-AG structure counters should match the ones on
disk, so check that.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: fix backwards endian conversion in scrub

Fix a backwards endian conversion of a constant.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

xfs: add xfs_verify_agino_or_null helper

Add a new helper to check that a per-AG inode pointer is either null or
points somewhere valid within that AG.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: remove xfs_rmap_ag_owner and friends

Owner information for static fs metadata can be defined readonly at
build time because it never changes across filesystems. This enables us
to reduce stack usage (particularly in scrub) because we can use the
statically defined oinfo structures.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: fix indentation and other whitespace problems in scrub/repair

Now that we've shortened everything, fix up all the indentation and
whitespace problems. There are no functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: shorten struct xfs_scrub_context to struct xfs_scrub

Shorten the name of the online fsck context structure. Whitespace
damage will be fixed by a subsequent patch. There are no functional
changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: shorten xfs_scrub_ prefix

Shorten all the metadata checking xfs_scrub_ prefixes to xchk_. After
this, the only xfs_scrub* symbols are the ones that pertain to both
scrub and repair. Whitespace damage will be fixed in a subsequent
patch. There are no functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: move various type verifiers to common file

New verification functions like xfs_verify_fsbno() and
xfs_verify_agino() are spread across multiple files and different
header files. They really don't fit cleanly into the places they've
been put, and have wider scope than the current header includes.

Move the type verifiers to a new file in libxfs (xfs-types.c) and
the prototypes to xfs_types.h where they will be visible to all the
code that uses the types.

Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}

/^ \* This program is free software/ {
hdr = 2.0;
next
}

/any later version./ {
tag = "GPL-2.0+"
next
}

/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}

/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}

/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}

// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}

END { }
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: hoist xfs_scrub_agfl_walk to libxfs as xfs_agfl_walk

This function is basically a generic AGFL block iterator, so promote it
to libxfs ahead of online repair wanting to use it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: superblock scrub should use short-lived buffers

Secondary superblocks are rarely used, so create a helper to read a
given non-primary AG's superblock and ensure that it won't stick around
hogging memory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: clean up scrub usage of KM_NOFS

All scrub code runs in transaction context, which means that memory
allocations are automatically run in PF_MEMALLOC_NOFS context. It's
therefore unnecessary to pass in KM_NOFS to allocation routines, so
clean them all out.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: convert XFS_AGFL_SIZE to a helper function

The AGFL size calculation is about to get more complex, so lets turn
the macro into a function first and remove the macro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
[darrick: forward port to newer kernel, simplify the helper]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: use memset to initialize xfs_scrub_agfl_info

Apparently different gcc versions have competing and
incompatible notions of how to initialize at declaration,
so just give up and fall back to the time-tested memset().

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: scrub in-core metadata

Whenever we load a buffer, explicitly re-call the structure verifier to
ensure that memory isn't corrupting things.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cross-reference refcount btree during scrub

During metadata btree scrub, we should cross-reference with the
reference counts.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cross-reference reverse-mapping btree

When scrubbing various btrees, we should cross-reference the records
with the reverse mapping btree and ensure that traversing the btree
finds the same number of blocks that the rmapbt thinks are owned by
that btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cross-reference inode btrees during scrub

Cross-reference the inode btrees with the other metadata when we
scrub the filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cross-reference bnobt records with cntbt

Scrub should make sure that each bnobt record has a corresponding
cntbt record.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cross-reference with the bnobt

When we're scrubbing various btrees, cross-reference the records with
the bnobt to ensure that we don't also think the space is free.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: introduce scrubber cross-referencing stubs

Create some stubs that will be used to cross-reference metadata records.
The actual cross-referencing will be filled in by subsequent patches.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: catch a few more error codes when scrubbing secondary sb

The superblock validation routines return a variety of error codes to
reject a mount request. For scrub we can assume that the mount
succeeded, so if we see these things appear when scrubbing secondary sb
X, we can treat them all like corruption.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: move all scrub input checking to xfs_scrub_validate

There were ad-hoc checks for some scrub types but not others;
mark each scrub type with ... it's type, and use that to validate
the allowed and/or required input fields.

Moving these checks out of xfs_scrub_setup_ag_header makes it
a thin wrapper, so unwrap it in the process.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[darrick: add xfs_ prefix to enum, check scrub args after checking type]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: check the uniqueness of the AGFL entries

Make sure we don't list a block twice in the agfl by copying the
contents of the AGFL to an array, sorting it, and looking for
duplicates. We can easily check that the number of agfl entries we see
actually matches the flcount, so do that too.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: scrub the AGI

Add a forgotten check to the AGI verifier, then wire up the scrub
infrastructure to check the AGI contents.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: scrub AGF and AGFL

Check the block references in the AGF and AGFL headers to make sure
they make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: scrub the secondary superblocks

Ensure that the geometry presented in the backup superblocks matches
the primary superblock so that repair can recover the filesystem if
that primary gets corrupted.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>