JIRA: https://issues.redhat.com/browse/RHEL-65728
commit d12bf8bac87a0d93e6e5fab67f399d1e3d3d5767
Author: Darrick J. Wong <djwong@kernel.org>
Date: Fri Dec 15 10:03:40 2023 -0800
xfs: create a ranged query function for refcount btrees
Implement ranged queries for refcount records. The next patch will use
this to scan refcount data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-25419
commit 6abc7aef85b1f42cb39a3149f4ab64ca255e41e6
Author: Darrick J. Wong <djwong@kernel.org>
Date: Tue Apr 11 19:00:10 2023 -0700
xfs: replace xfs_btree_has_record with a general keyspace scanner
The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range. Unfortunately, that's not
sufficient for scrub. We want to be able to tell if a range of keyspace
for a btree is devoid of records, is totally mapped to records, or is
somewhere in between. By forcing this to be a boolean, we conflated
sparseness and fullness, which caused scrub to return incorrect results.
Fix the API so that we can tell the caller which of those three is the
current state.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-25419
commit 2b30cc0bf0589d1ea0506c019b9b81de77535c87
Author: Darrick J. Wong <djwong@kernel.org>
Date: Tue Apr 11 19:00:02 2023 -0700
xfs: standardize ondisk to incore conversion for refcount btrees
Create a xfs_refcount_check_irec function to detect corruption in btree
records. Fix all xfs_refcount_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-25419
commit 00e7b3bac1dc8961bd5aa9d39e79131c6bd81181
Author: Darrick J. Wong <djwong@kernel.org>
Date: Tue Apr 11 18:59:55 2023 -0700
xfs: give xfs_refcount_intent its own perag reference
Give the xfs_refcount_intent a passive reference to the perag structure
data. This reference will be used to enable scrub intent draining
functionality in subsequent patches. Any space being modified by a
refcount intent is already allocated, so we need to be able to operate
even if the AG is being shrunk or offlined.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-2002
commit 0b11553ec54a6d88907e60d0595dbcef98539747
Author: Darrick J. Wong <djwong@kernel.org>
Date: Wed Feb 1 10:16:04 2023 -0800
xfs: pass refcount intent directly through the log intent code
Pass the incore refcount intent through the CUI logging code instead of
repeatedly boxing and unboxing parameters.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-2002
commit 8b972158afcaa66c538c3ee1d394f096fcd238a8
Author: Darrick J. Wong <djwong@kernel.org>
Date: Mon Oct 10 11:13:20 2022 -0700
xfs: rename XFS_REFC_COW_START to _COWFLAG
We've been (ab)using XFS_REFC_COW_START as both an integer quantity and
a bit flag, even though it's *only* a bit flag. Rename the variable to
reflect its nature and update the cast target since we're not supposed
to be comparing it to xfs_agblock_t now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-2002
commit f492135df0aa0417337f9b8b1cc6d6a994d61d25
Author: Darrick J. Wong <djwong@kernel.org>
Date: Wed Oct 26 14:31:27 2022 -0700
xfs: refactor domain and refcount checking
Create a helper function to ensure that CoW staging extent records have
a single refcount and that shared extent records have more than 1
refcount. We'll put this to more use in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-2002
commit 9a50ee4f8db6e4dd0d8d757b7adaf0591776860a
Author: Darrick J. Wong <djwong@kernel.org>
Date: Mon Oct 10 09:06:24 2022 -0700
xfs: track cow/shared record domains explicitly in xfs_refcount_irec
Just prior to committing the reflink code into upstream, the xfs
maintainer at the time requested that I find a way to shard the refcount
records into two domains -- one for records tracking shared extents, and
a second for tracking CoW staging extents. The idea here was to
minimize mount time CoW reclamation by pushing all the CoW records to
the right edge of the keyspace, and it was accomplished by setting the
upper bit in rc_startblock. We don't allow AGs to have more than 2^31
blocks, so the bit was free.
Unfortunately, this was a very late addition to the codebase, so most of
the refcount record processing code still treats rc_startblock as a u32
and pays no attention to whether or not the upper bit (the cow flag) is
set. This is a weakness is theoretically exploitable, since we're not
fully validating the incoming metadata records.
Fuzzing demonstrates practical exploits of this weakness. If the cow
flag of a node block key record is corrupted, a lookup operation can go
to the wrong record block and start returning records from the wrong
cow/shared domain. This causes the math to go all wrong (since cow
domain is still implicit in the upper bit of rc_startblock) and we can
crash the kernel by tricking xfs into jumping into a nonexistent AG and
tripping over xfs_perag_get(mp, <nonexistent AG>) returning NULL.
To fix this, start tracking the domain as an explicit part of struct
xfs_refcount_irec, adjust all refcount functions to check the domain
of a returned record, and alter the function definitions to accept them
where necessary.
Found by fuzzing keys[2].cowflag = add in xfs/464.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2167832
commit 4ed6435cc369cce722966983f6e07b872562276f
Author: Darrick J. Wong <djwong@kernel.org>
Date: Mon Apr 25 18:37:15 2022 -0700
xfs: stop artificially limiting the length of bunmap calls
In commit e1a4e37cc7, we clamped the length of bunmapi calls on the
data forks of shared files to avoid two failure scenarios: one where the
extent being unmapped is so sparsely shared that we exceed the
transaction reservation with the sheer number of refcount btree updates
and EFI intent items; and the other where we attach so many deferred
updates to the transaction that we pin the log tail and later the log
head meets the tail, causing the log to livelock.
We avoid triggering the first problem by tracking the number of ops in
the refcount btree cursor and forcing a requeue of the refcount intent
item any time we think that we might be close to overflowing. This has
been baked into XFS since before the original e1a4 patch.
A recent patchset fixed the second problem by changing the deferred ops
code to finish all the work items created by each round of trying to
complete a refcount intent item, which eliminates the long chains of
deferred items (27dad); and causing long-running transactions to relog
their intent log items when space in the log gets low (74f4d).
Because this clamp affects /any/ unmapping request regardless of the
sharing factors of the component blocks, it degrades the performance of
all large unmapping requests -- whereas with an unshared file we can
unmap millions of blocks in one go, shared files are limited to
unmapping a few thousand blocks at a time, which causes the upper level
code to spin in a bunmapi loop even if it wasn't needed.
This also eliminates one more place where log recovery behavior can
differ from online behavior, because bunmapi operations no longer need
to requeue. The fstest generic/447 was created to test the old fix, and
it still passes with this applied.
Partial-revert-of: e1a4e37cc7 ("xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent")
Depends: 27dada070d ("xfs: change the order in which child and parent defer ops ar finished")
Depends: 74f4d6a1e0 ("xfs: only relog deferred intent items if free space in the log gets low")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2167832
commit c47260d4ea2ac11ce607d6ac1e0ca5528f42f482
Author: Darrick J. Wong <djwong@kernel.org>
Date: Tue Apr 26 15:29:54 2022 -0700
xfs: count EFIs when deciding to ask for a continuation of a refcount update
A long time ago, I added to XFS the ability to use deferred reference
count operations as part of a transaction chain. This enabled us to
avoid blowing out the transaction reservation when the blocks in a
physical extent all had different reference counts because we could ask
the deferred operation manager for a continuation, which would get us a
clean transaction.
The refcount code asks for a continuation when the number of refcount
record updates reaches the point where we think that the transaction has
logged enough full btree blocks due to refcount (and free space) btree
shape changes and refcount record updates that we're in danger of
overflowing the transaction.
We did not previously count the EFIs logged to the refcount update
transaction because the clamps on the length of a bunmap operation were
sufficient to avoid overflowing the transaction reservation even in the
worst case situation where every other block of the unmapped extent is
shared.
Unfortunately, the restrictions on bunmap length avoid failure in the
worst case by imposing a maximum unmap length of ~3000 blocks, even for
non-pathological cases. This seriously limits performance when freeing
large extents.
Therefore, track EFIs with the same counter as refcount record updates,
and use that information as input into when we should ask for a
continuation. This enables the next patch to drop the clumsy bunmap
limitation.
Depends: 27dada070d ("xfs: change the order in which child and parent defer ops ar finished")
Depends: 74f4d6a1e0 ("xfs: only relog deferred intent items if free space in the log gets low")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2125724
Create slab caches for the high-level structures that coordinate
deferred intent items, since they're used fairly heavily.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
(cherry picked from commit f3c799c22c661e181c71a0d9914fc923023f65fb)
Bugzilla: https://bugzilla.redhat.com/2125724
Rearrange these structs to reduce the amount of unused padding bytes.
This saves eight bytes for each of the three structs changed here, which
means they're now all (rmap/bmap are 64 bytes, refc is 32 bytes) even
powers of two.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
(cherry picked from commit 9e253954acf53227f33d307f5ac5ff94c1ca5880)
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2083143
Upstream Status: linux.git
commit 159eb69dba8baf6d5b58b69936920fb311324c82
Author: Darrick J. Wong <djwong@kernel.org>
Date: Tue Aug 10 17:02:16 2021 -0700
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>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Remove the return value from the functions that schedule deferred
refcount operations since they never fail and do not return status.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The majority of remaining references to struct xfs_defer_ops in XFS
are associated with xfs_defer_add(). At this point, there are no
more external xfs_defer_ops users left. All instances of
xfs_defer_ops are embedded in the transaction, which means we can
safely pass the transaction down to the dfops add interface.
Update xfs_defer_add() to receive the transaction as a parameter.
Various subsystems implement wrappers to allocate and construct the
context specific data structures for the associated deferred
operation type. Update these to also carry the transaction down as
needed and clean up unused dfops parameters along the way.
This removes most of the remaining references to struct
xfs_defer_ops throughout the code and facilitates removal of the
structure.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[darrick: fix unused variable warnings with ftrace disabled]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The dfops infrastructure ->finish_item() callback passes the
transaction and dfops as separate parameters. Since dfops is always
part of a transaction, the latter parameter is no longer necessary.
Remove it from the various callbacks.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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>
Add a couple of functions to the refcount btree and generic btree code
that will be used to repair the refcountbt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Expose various helpers that the repair code will want to use.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a couple of functions to the refcount btrees that will be used
to cross-reference metadata against the refcountbt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
In a pathological scenario where we are trying to bunmapi a single
extent in which every other block is shared, it's possible that trying
to unmap the entire large extent in a single transaction can generate so
many EFIs that we overflow the transaction reservation.
Therefore, use a heuristic to guess at the number of blocks we can
safely unmap from a reflink file's data fork in an single transaction.
This should prevent problems such as the log head slamming into the tail
and ASSERTs that trigger because we've exceeded the transaction
reservation.
Note that since bunmapi can fail to unmap the entire range, we must also
teach the deferred unmap code to roll into a new transaction whenever we
get low on reservation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[hch: random edits, all bugs are my fault]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Due to the way the CoW algorithm in XFS works, there's an interval
during which blocks allocated to handle a CoW can be lost -- if the FS
goes down after the blocks are allocated but before the block
remapping takes place. This is exacerbated by the cowextsz hint --
allocated reservations can sit around for a while, waiting to get
used.
Since the refcount btree doesn't normally store records with refcount
of 1, we can use it to record these in-progress extents. In-progress
blocks cannot be shared because they're not user-visible, so there
shouldn't be any conflicts with other programs. This is a better
solution than holding EFIs during writeback because (a) EFIs can't be
relogged currently, (b) even if they could, EFIs are bound by
available log space, which puts an unnecessary upper bound on how much
CoW we can have in flight, and (c) we already have a mechanism to
track blocks.
At mount time, read the refcount records and free anything we find
with a refcount of 1 because those were in-progress when the FS went
down.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
These functions will be used by the other reflink functions to find
the maximum length of a range of shared blocks.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Plumb in the upper level interface to schedule and finish deferred
refcount operations via the deferred ops mechanism.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Provide a mechanism for higher levels to create CUI/CUD items, submit
them to the log, and a stub function to deal with recovered CUI items.
These parts will be connected to the refcountbt in a later patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Implement the generic btree operations required to manipulate refcount
btree blocks. The implementation is similar to the bmapbt, though it
will only allocate and free blocks from the AG.
Since the refcount root and level fields are separate from the
existing roots and levels array, they need a separate logging flag.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[hch: fix logging of AGF refcount btree fields]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Bill O'Donnell
Carlos Maiolino
Brian Foster
Dave Chinner
Darrick J. Wong