xfs_trans_alloc_empty can't return errors, so return the allocated
transaction directly instead of an output double pointer argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Online fsck was finished a year ago, in Linux 6.10. The exchange-range
syscall and parent pointers were merged in the same cycle. None of
these have encountered any serious errors in the year that they've been
in the kernel (or the many many years they've been under development) so
let's drop the shouty warnings.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Zone file systems reuse the basic RT group enabled XFS file system
structure to support a mode where each RT group is always written from
start to end and then reset for reuse (after moving out any remaining
data). There are few minor but important changes, which are indicated
by a new incompat flag:
1) there are no bitmap and summary inodes, thus the
/rtgroups/{rgno}.{bitmap,summary} metadir files do not exist and the
sb_rbmblocks superblock field must be cleared to zero.
2) there is a new superblock field that specifies the start of an
internal RT section. This allows supporting SMR HDDs that have random
writable space at the beginning which is used for the XFS data device
(which really is the metadata device for this configuration), directly
followed by a RT device on the same block device. While something
similar could be achieved using dm-linear just having a single device
directly consumed by XFS makes handling the file systems a lot easier.
3) Another superblock field that tracks the amount of reserved space (or
overprovisioning) that is never used for user capacity, but allows GC
to run more smoothly.
4) an overlay of the cowextsize field for the rtrmap inode so that we
can persistently track the total amount of rtblocks currently used in
a RT group. There is no data structure other than the rmap that
tracks used space in an RT group, and this counter is used to decide
when a RT group has been entirely emptied, and to select one that
is relatively empty if garbage collection needs to be performed.
While this counter could be tracked entirely in memory and rebuilt
from the rmap at mount time, that would lead to very long mount times
with the large number of RT groups implied by the number of hardware
zones especially on SMR hard drives with 256MB zone sizes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
I received a report from the release engineering side of the house that
xfs_scrub without the -n flag (aka fix it mode) would try to fix a
broken filesystem even on a kernel that doesn't have online repair built
into it:
# xfs_scrub -dTvn /mnt/test
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Phase 1: Find filesystem geometry.
/mnt/test: using 1 threads to scrub.
Phase 1: Memory used: 132k/0k (108k/25k), time: 0.00/ 0.00/ 0.00s
<snip>
Phase 4: Repair filesystem.
<snip>
Info: /mnt/test/some/victimdir directory entries: Attempting repair. (repair.c line 351)
Corruption: /mnt/test/some/victimdir directory entries: Repair unsuccessful; offline repair required. (repair.c line 204)
Source: https://blogs.oracle.com/linux/post/xfs-online-filesystem-repair
It is strange that xfs_scrub doesn't refuse to run, because the kernel
is supposed to return EOPNOTSUPP if we actually needed to run a repair,
and xfs_io's repair subcommand will perror that. And yet:
# xfs_io -x -c 'repair probe' /mnt/test
#
The first problem is commit dcb660f922 (4.15) which should have had
xchk_probe set the CORRUPT OFLAG so that any of the repair machinery
will get called at all.
It turns out that some refactoring that happened in the 6.6-6.8 era
broke the operation of this corner case. What we *really* want to
happen is that all the predicates that would steer xfs_scrub_metadata()
towards calling xrep_attempt() should function the same way that they do
when repair is compiled in; and then xrep_attempt gets to return the
fatal EOPNOTSUPP error code that causes the probe to fail.
Instead, commit 8336a64eb7 (6.6) started the failwhale swimming by
hoisting OFLAG checking logic into a helper whose non-repair stub always
returns false, causing scrub to return "repair not needed" when in fact
the repair is not supported. Prior to that commit, the oflag checking
that was open-coded in scrub.c worked correctly.
Similarly, in commit 4bdfd7d157 (6.8) we hoisted the IFLAG_REPAIR
and ALREADY_FIXED logic into a helper whose non-repair stub always
returns false, so we never enter the if test body that would have called
xrep_attempt, let alone fail to decode the OFLAGs correctly.
The final insult (yes, we're doing The Naked Gun now) is commit
48a72f6086 (6.8) in which we hoisted the "are we going to try a
repair?" predicate into yet another function with a non-repair stub
always returns false.
Fix xchk_probe to trigger xrep_probe if repair is enabled, or return
EOPNOTSUPP directly if it is not. For all the other scrub types, we
need to fix the header predicates so that the ->repair functions (which
are all xrep_notsupported) get called to return EOPNOTSUPP. Commit
48a72 is tagged here because the scrub code prior to LTS 6.12 are
incomplete and not worth patching.
Reported-by: David Flynn <david.flynn@oracle.com>
Cc: <stable@vger.kernel.org> # v6.8
Fixes: 8336a64eb7 ("xfs: don't complain about unfixed metadata when repairs were injected")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Port the data device's refcount btree repair code to the realtime
refcount btree.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add code to scrub realtime refcount btrees. Similar to the refcount
btree checking code for the data device, we walk the rmap btree for each
refcount record to confirm that the reference counts are correct.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair the realtime rmap btree while mounted. Similar to the regular
rmap btree repair code, we walk the data fork mappings of every realtime
file in the filesystem to collect reverse-mapping records in an xfarray.
Then we sort the xfarray, and use the btree bulk loader to create a new
rtrmap btree ondisk. Finally, we swap the btree roots, and reap the old
blocks in the usual way.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Check the realtime reverse mapping btree against the rtbitmap, and
modify the rtbitmap scrub to check against the rtrmapbt.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When a writer thread executes a chain of log intent items for the
realtime volume, the ILOCKs taken during each step are for each rt
metadata file, not the entire rt volume itself. Although scrub takes
all rt metadata ILOCKs, this isn't sufficient to guard against scrub
checking the rt volume while that writer thread is in the middle of
finishing a chain because there's no higher level locking primitive
guarding the realtime volume.
When there's a collision, cross-referencing between data structures
(e.g. rtrmapbt and rtrefcountbt) yields false corruption events; if
repair is running, this results in incorrect repairs, which is
catastrophic.
Fix this by adding to the mount structure the same drain that we use to
protect scrub against concurrent AG updates, but this time for the
realtime volume.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair the realtime superblock if it has become out of date with the
primary superblock.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the pointers to the RT bitmap and summary inodes as well as the
summary cache to the rtgroups structure to prepare for having a
separate bitmap and summary inodes for each rtgroup.
Code using the inodes now needs to operate on a rtgroup. Where easily
possible such code is converted to iterate over all rtgroups, else
rtgroup 0 (the only one that can currently exist) is hardcoded.
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>
Create a state tracking structure and helpers to initialize the tracking
structure so that we can check metadata records against the realtime
space management metadata. Right now this is limited to grabbing the
incore rtgroup object, but we'll eventually add to the tracking
structure the ILOCK state and btree cursors.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a new scrubber type that checks that well known metadata
directory paths are connected to the metadata inode that the incore
structures think is in use. For example, check that "/quota/user" in
the metadata directory tree actually points to
mp->m_quotainfo->qi_uquotaip->i_ino.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Refactor the open-coded warnings about EXPERIMENTAL feature use into a
standard helper before we go adding more experimental features.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Don't open-code what the kernel already provides.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
The atomic file exchange-range functionality is now a permanent
filesystem feature instead of a dynamic log-incompat feature. It cannot
be turned on at runtime, so we no longer need the XCHK_FSGATES flags and
whatnot that supported it. Remove the flag and the enable function, and
move the xfs_has_exchange_range checks to the start of the repair
functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If a program wants us to perform a scrub on a file handle and the fd
passed to ioctl() is not the file referenced in the handle, iget the
file once and pass it into the scrub code. This amortizes the untrusted
iget lookup over /all/ the scrubbers mentioned in the scrubv call.
When running fstests in "rebuild all metadata after each test" mode, I
observed a 10% reduction in runtime on account of avoiding repeated
inobt lookups.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Introduce a variant on XFS_SCRUB_METADATA that allows for a vectored
mode. The caller specifies the principal metadata object that they want
to scrub (allocation group, inode, etc.) once, followed by an array of
scrub types they want called on that object. The kernel runs the scrub
operations and writes the output flags and errno code to the
corresponding array element.
A new pseudo scrub type BARRIER is introduced to force the kernel to
return to userspace if any corruptions have been found when scrubbing
the previous scrub types in the array. This enables userspace to
schedule, for example, the sequence:
1. data fork
2. barrier
3. directory
If the data fork scrub is clean, then the kernel will perform the
directory scrub. If not, the barrier in 2 will exit back to userspace.
The alternative would have been an interface where userspace passes a
pointer to an empty buffer, and the kernel formats that with
xfs_scrub_vecs that tell userspace what it scrubbed and what the outcome
was. With that the kernel would have to communicate that the buffer
needed to have been at least X size, even though for our cases
XFS_SCRUB_TYPE_NR + 2 would always be enough.
Compared to that, this design keeps all the dependency policy and
ordering logic in userspace where it already resides instead of
duplicating it in the kernel. The downside of that is that it needs the
barrier logic.
When running fstests in "rebuild all metadata after each test" mode, I
observed a 10% reduction in runtime due to fewer transitions across the
system call boundary.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the scrub ioctl handler to scrub.c to keep the code together and to
reduce unnecessary code when CONFIG_XFS_ONLINE_SCRUB=n.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We really don't want to call cond_resched every single time we go
through a loop in scrub -- there may be billions of records, and probing
into the scheduler itself has overhead. Reduce this overhead by only
calling cond_resched 10x per second; and add a counter so that we only
check jiffies once every 1000 records or so.
Surprisingly, this reduces scrub-only fstests runtime by about 2%. I
used the bmapinflate xfs_db command to produce a billion-extent file and
this stupid gadget reduced the scrub runtime by about 4%.
From a stupid microbenchmark of calling these things 1 billion times, I
estimate that cond_resched costs about 5.5ns per call; jiffes costs
about 0.3ns per read; and fatal_signal_pending costs about 0.4ns per
call.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair corruptions in the directory tree itself. Cycles are broken by
removing an incoming parent->child link. Multiply-owned directories are
fixed by pruning the extra parent -> child links Disconnected subtrees
are reconnected to the lost and found.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a new scrubber that detects corruptions within the directory tree
structure itself. It can detect directories with multiple parents;
loops within the directory tree; and directory loops not accessible from
the root.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Adapt the orphanage's adoption code to update the child file's parent
pointers as part of the reparenting process. Also ensure that the child
has an attr fork to receive the parent pointer update, since the runtime
code assumes one exists.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When a file-based metadata structure is being scrubbed in
xchk_metadata_inode_subtype, we should create an entirely new scrub
context so that each scrubber doesn't trip over another's buffers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If a symbolic link target looks bad, try to sift through the rubble to
find as much of the target buffer that we can, and stage a new target
(short or remote format as needed) in a temporary file and use the
atomic extent swapping mechanism to commit the results. In the worst
case, we replace the target with an overly long filename that cannot
possibly resolve.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're repairing a directory structure or fixing the dotdot entry of
a subdirectory, it's possible that we won't ever find a parent for the
subdirectory. When this is the case, move it to the orphanage, aka
/lost+found.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Teach the online repair code to fix parent pointers for directories.
For now, this means correcting the dotdot entry of an existing directory
that is otherwise consistent.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If a directory looks like it's in bad shape, try to sift through the
rubble to find whatever directory entries we can, scan the directory
tree for the parent (if needed), stage the new directory contents in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the extended attributes look bad, try to sift through the rubble to
find whatever keys/values we can, stage a new attribute structure in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair the realtime summary data by constructing a new rtsummary file in
the scrub temporary file, then atomically swapping the contents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create some new routines to exchange the contents of a temporary file
created to stage a repair with another ondisk file. This will be used
by the realtime summary repair function to commit atomically the new
rtsummary data, which will be staged in the tempfile.
The rest of XFS coordinates access to the realtime metadata inodes
solely through the ILOCK. For repair to hold its exclusive access to
the realtime summary file, it has to allocate a single large transaction
and roll it repeatedly throughout the repair while holding the ILOCK.
In turn, this means that for now there's only a partial file mapping
exchange implementation for the temporary file because we can only work
within an existing transaction.
For now, the only tempswap functions needed here are to estimate the
resource requirements of the exchange, reserve more space/quota to an
existing transaction, and kick off the actual exchange. The rest will
be added in a later patch in preparation for repairing xattrs and
directories.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Teach the online repair code how to create temporary files or
directories. These temporary files can be used to stage reconstructed
information until we're ready to perform an atomic extent swap to commit
the new metadata.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Hook the regular rmap code when an rmapbt repair operation is running so
that we can unlock the AGF buffer to scan the filesystem and keep the
in-memory btree up to date during the scan.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Rebuild the reverse mapping btree from all primary metadata. This first
patch establishes the bare mechanics of finding records and putting
together a new ondisk tree; more complex pieces are needed to make it
work properly.
Link: Documentation/filesystems/xfs-online-fsck-design.rst
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Adapt the generic btree cursor code to be able to create a btree whose
buffers come from a (presumably in-memory) buftarg with a header block
that's specific to in-memory btrees. We'll connect this to other parts
of online scrub in the next patches.
Note that in-memory btrees always have a block size matching the system
memory page size for efficiency reasons. There are also a few things we
need to do to finalize a btree update; that's covered in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the same summary counter calculation infrastructure to generate new
values for the in-core summary counters. The difference between the
scrubber and the repairer is that the repairer will freeze the fs during
setup, which means that the values should match exactly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If scrub finds that everything is ok with the filesystem, we need a way
to tell the health tracking that it can let go of indirect health flags,
since indirect flags only mean that at some point in the past we lost
some context.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fix the file link counts since we just computed the correct ones.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create the necessary hooks in the directory operations
(create/link/unlink/rename) code so that our live nlink scrub code can
stay up to date with link count updates in the rest of the filesystem.
This will be the means to keep our shadow link count information up to
date while the scan runs in real time.
In online fsck part 2, we'll use these same hooks to handle repairs
to directories and parent pointer information.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create the necessary scrub code to walk the filesystem's directory tree
so that we can compute file link counts. Similar to quotacheck, we
create an incore shadow array of link count information and then we walk
the filesystem a second time to compare the link counts. We need live
updates to keep the information up to date during the lengthy scan, so
this scrubber remains disabled until the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the shadow quota counters that live quotacheck creates to reset the
incore dquot counters.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a shadow dqtrx system in the quotacheck code that hooks the
regular dquot counter update code. This will be the means to keep our
copy of the dquot counters up to date while the scan runs in real time.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a new trio of scrub functions to check quota counters. While the
dquots themselves are filesystem metadata and should be checked early,
the dquot counter values are computed from other metadata and are
therefore summary counters. We don't plug these into the scrub dispatch
just yet, because we still need to be able to watch quota updates while
doing our scan.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fix all the file metadata surrounding the realtime bitmap file, which
includes the rt geometry, file size, forks, and space mappings. The
bitmap contents themselves cannot be fixed without rt rmap, so that will
come later.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
XFS filesystems always have a realtime bitmap and summary file, even if
there has never been a realtime volume attached. Always check them.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Try to repair errors that we see in file CoW forks so that we don't do
stupid things like remap garbage into a file. There's not a lot we can
do with the COW fork -- the ondisk metadata record only that the COW
staging extents are owned by the refcount btree, which effectively means
that we can't reconstruct this incore structure from scratch.
Actually, this is even worse -- we can't touch written extents, because
those map space that are actively under writeback, and there's not much
to do with delalloc reservations. Hence we can only detect crosslinked
unwritten extents and fix them by punching out the problematic parts and
replacing them with delalloc extents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There are a couple of conditions that userspace can set to force repairs
of metadata. These really belong in the repair code and not open-coded
into the check code, so refactor them into a helper.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
