simple_empty() and simple_offset_empty() perform the same task.
The latter's use as a canary to find bugs has not found any new
issues. A subsequent patch will remove the use of the mtree for
iterating directory contents, so revert back to using a similar
mechanism for determining whether a directory is indeed empty.
Only one such mechanism is ever needed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-3-cel@kernel.org
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Testing shows that the EBUSY error return from mtree_alloc_cyclic()
leaks into user space. The ERRORS section of "man creat(2)" says:
> EBUSY O_EXCL was specified in flags and pathname refers
> to a block device that is in use by the system
> (e.g., it is mounted).
ENOSPC is closer to what applications expect in this situation.
Note that the normal range of simple directory offset values is
2..2^63, so hitting this error is going to be rare to impossible.
Fixes: 6faddda69f ("libfs: Add directory operations for stable offsets")
Cc: stable@vger.kernel.org # v6.9+
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-2-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Nam Cao <namcao@linutronix.de> says:
In /proc/PID/stat, there is the kstkesp field which is the stack pointer of
a thread. While the thread is active, this field reads zero. But during a
coredump, it should have a valid value.
However, at the moment, kstkesp is zero even during coredump.
The first commit fixes this problem, and the second commit adds a selftest
to detect if this problem appears again in the future.
* patches from https://lore.kernel.org/r/cover.1735805772.git.namcao@linutronix.de:
selftests: coredump: Add stackdump test
fs/proc: do_task_stat: Fix ESP not readable during coredump
Link: https://lore.kernel.org/r/cover.1735805772.git.namcao@linutronix.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
The field "eip" (instruction pointer) and "esp" (stack pointer) of a task
can be read from /proc/PID/stat. These fields can be interesting for
coredump.
However, these fields were disabled by commit 0a1eb2d474 ("fs/proc: Stop
reporting eip and esp in /proc/PID/stat"), because it is generally unsafe
to do so. But it is safe for a coredumping process, and therefore
exceptions were made:
- for a coredumping thread by commit fd7d56270b ("fs/proc: Report
eip/esp in /prod/PID/stat for coredumping").
- for all other threads in a coredumping process by commit cb8f381f16
("fs/proc/array.c: allow reporting eip/esp for all coredumping
threads").
The above two commits check the PF_DUMPCORE flag to determine a coredump thread
and the PF_EXITING flag for the other threads.
Unfortunately, commit 9230738308 ("coredump: Don't perform any cleanups
before dumping core") moved coredump to happen earlier and before PF_EXITING is
set. Thus, checking PF_EXITING is no longer the correct way to determine
threads in a coredumping process.
Instead of PF_EXITING, use PF_POSTCOREDUMP to determine the other threads.
Checking of PF_EXITING was added for coredumping, so it probably can now be
removed. But it doesn't hurt to keep.
Fixes: 9230738308 ("coredump: Don't perform any cleanups before dumping core")
Cc: stable@vger.kernel.org
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <kees@kernel.org>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/d89af63d478d6c64cc46a01420b46fd6eb147d6f.1735805772.git.namcao@linutronix.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
This adds a new inode field, bi_depth, for directory inodes: this allows
us to make the check_directory_structure pass much more efficient.
Currently, to ensure the filesystem is fully connect and has no loops,
for every directory we follow backpointers until we find the root. But
by adding a depth counter, it sufficies to only check the parent of each
directory, and check that the parent's bi_depth is smaller.
(fsck doesn't require that bi_depth = parent->bi_depth + 1; if a rename
causes bi_depth off, but the chain to the root is still strictly
decreasing, then the algorithm still works and there's no need for fsck
to fixup the bi_depth fields).
We've already checked backpointers, so we know that every directory
(excluding the root)has a valid parent: if bi_depth is always
decreasing, every chain must terminate, and terminate at the root
directory.
bi_depth will not necessarily be correct when fsck runs, due to
directory renames - we can't change bi_depth on every child directory
when renaming a directory. That's ok; fsck will silently fix the
bi_depth field as needed, and future fsck runs will be much faster.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Now that bch2_move_get_io_opts() re-propagates changed inode io options
to bch_extent_rebalance, we can properly suport changing IO path options
for reflinked data.
Changing a per-file IO path option, either via the xattr interface or
via the BCHFS_IOC_REINHERIT_ATTRS ioctl, will now trigger a scan (the
inode number is marked as needing a scan, via
bch2_set_rebalance_needs_scan()), and rebalance will use
bch2_move_data(), which will walk the inode number and pick up the new
options.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, io path option changes on a file would be picked up
automatically and applied to existing data - but not for reflinked data,
as we had no way of doing this safely. A user may have had permission to
copy (and reflink) a given file, but not write to it, and if so they
shouldn't be allowed to change e.g. nr_replicas or other options.
This uses the incompat feature mechanism in the previous patch to add a
new incompatible flag to bch_reflink_p, indicating whether a given
reflink pointer may propagate io path option changes back to the
indirect extent.
In this initial patch we're only setting it for the source extents.
We'd like to set it for the destination in a reflink copy, when the user
has write access to the source, but that requires mnt_idmap which is not
curretly plumbed up to remap_file_range.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We've been getting away from feature bits: they don't have any kind of
ordering, and thus it's possible for people to enable weird combinations
of features that were never tested or intended to be run.
Much better to just give every new feature, compatible or incompatible,
a version number.
Additionally, we probably won't ever rev the major version number: major
version numbers represent incompatible versions, but that doesn't really
fit with how we actually roll out incompatible features - we need a
better way of rolling out incompatible features.
So, this patch adds two new superblock fields:
- BCH_SB_VERSION_INCOMPAT
- BCH_SB_VERSION_INCOMPAT_ALLOWED
BCH_SB_VERSION_INCOMPAT_ALLOWED indicates that incompatible features up
to version number x are allowed to be used without user prompting, but
it does not by itself deny old versions from mounting.
BCH_SB_VERSION_INCOMPAT does deny old versions from mounting, and must
be <= BCH_SB_VERSION_INCOMPAT_ALLOWED.
BCH_SB_VERSION_INCOMPAT will only be set when a codepath attempts to use
an incompatible feature, so as to not unnecessarily break compatibility
with old versions.
bch2_request_incompat_feature() is the new interface to check if an
incompatible feature may be used.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The backpointers passes, check_backpointers_to_extents() and
check_extents_to_backpointers() are the most expensive fsck passes.
Now that we're running the same check and repair code when using a
backpointer at runtime (via bch2_backpointer_get_key()) that fsck does,
there's no reason fsck needs to - except to verify that the filesystem
really has no errors in debug mode.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Continuing on with the self healing theme, we should be running any
check and repair code at runtime that we can - instead of declaring the
filesystemt inconsistent.
This will also let us skip running the backpointers -> extents fsck pass
except in debug mode.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Instead of walking every extent and every backpointer it points to,
first sum up backpointers in each bucket and check for mismatches, and
only look for missing backpointers if mismatches were detected, and only
check extents in those buckets.
This is a major fsck scalability improvement, since the two backpointers
passes (backpointers -> extents and extents -> backpointers) are the
most expensive fsck passes by far.
Additionally, to speed up the upgrade for backpointer bucket gens, or in
situations when we have to rebuild alloc info, add a special case for
when no backpointers are found in a bucket - don't check each individual
backpointer (in particular, avoiding the write buffer flushes), just
recreate them.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In an upcoming patch bch2_backpointer_get_key() will be repairing when
it finds a dangling backpointer; it will need to flush the btree write
buffer before it can definitively say there's an error.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch_backpointer no longer contains the bucket_offset field, it's just a
direct LBA mapping (with low bits to account for compressed extent
splitting), so we don't need to refer to the device to construct it
anymore.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Fix sort order for disk accounting keys, in order to fix a regression on
mount times.
The typetag is now the most significant byte of the key, meaning disk
accounting keys of the same type now sort together.
This lets us skip over disk accounting keys that aren't mirrored in
memory when reading accounting at startup, instead of having them
interleaved with other counter types.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
New on disk format version: backpointers new include the generation
number of the bucket they refer to, and the obsolete bucket_offset field
(no longer needed because we no longer store backpointers in alloc keys)
is gone.
This is an expensive forced upgrade - hopefully the last; we have to run
the extents_to_backpointers recovery pass to regenerate backpointers.
It's a forced incompatible upgrade because the alternative would've been
permamently making backpointers bigger, and as one of the biggest btrees
(along with the extents btree) that's not an ideal option.
It's worth it though, because this allows us to make the
check_extents_to_backpointers pass drastically cheaper: an upcoming
patch changes it to sum up backpointers in a bucket and check the sum
against the sector counts for that bucket, only looking for missing
backpointers if they don't match (and then only for specific buckets).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull btrfs fixes from David Sterba:
"A few more fixes that accumulated over the last two weeks, fixing some
user reported problems:
- swapfile fixes:
- conditional reschedule in the activation loop
- fix race with memory mapped file when activating
- make activation loop interruptible
- rework and fix extent sharing checks
- folio fixes:
- in send, recheck folio mapping after unlock
- in relocation, recheck folio mapping after unlock
- fix waiting for encoded read io_uring requests
- fix transaction atomicity when enabling simple quotas
- move COW block trace point before the block gets freed
- print various sizes in sysfs with correct endianity"
* tag 'for-6.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: sysfs: fix direct super block member reads
btrfs: fix transaction atomicity bug when enabling simple quotas
btrfs: avoid monopolizing a core when activating a swap file
btrfs: allow swap activation to be interruptible
btrfs: fix swap file activation failure due to extents that used to be shared
btrfs: fix race with memory mapped writes when activating swap file
btrfs: check folio mapping after unlock in put_file_data()
btrfs: check folio mapping after unlock in relocate_one_folio()
btrfs: fix use-after-free when COWing tree bock and tracing is enabled
btrfs: fix use-after-free waiting for encoded read endios
Pull smb client fixes from Steve French:
- fix caching of files that will be reused for write
- minor cleanup
* tag '6.13-rc4-SMB3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: Remove unused is_server_using_iface()
smb: enable reuse of deferred file handles for write operations
The following sysfs entries are reading super block member directly,
which can have a different endian and cause wrong values:
- sys/fs/btrfs/<uuid>/nodesize
- sys/fs/btrfs/<uuid>/sectorsize
- sys/fs/btrfs/<uuid>/clone_alignment
Thankfully those values (nodesize and sectorsize) are always aligned
inside the btrfs_super_block, so it won't trigger unaligned read errors,
just endian problems.
Fix them by using the native cached members instead.
Fixes: df93589a17 ("btrfs: export more from FS_INFO to sysfs")
CC: stable@vger.kernel.org
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable reflink for realtime devices, as long as the realtime allocation
unit is a single fsblock.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're rebuilding the data fork of a realtime file, we need to
cross-reference each mapping with the rt refcount btree to ensure that
the reflink flag is set if there are any shared extents found.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Plumb knowledge of refcount btrees into the inode core repair code.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
Walk the realtime refcount btree to find the CoW staging extents when
we're rebuilding the realtime rmap btree.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're rebuilding the data device rmap, if we encounter a "refcount"
format fork, we have to walk the (realtime) refcount btree inode to
build the appropriate mappings.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're rebuilding the realtime bitmap, check the proposed free
extents against the rt refcount btree to make sure we don't commit any
grievous errors.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Quota space usage is allowed to exceed the size of the physical storage
when reflink is enabled. Now that we have reflink for the realtime
volume, apply this same logic to the rtb repair logic.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add a new XFS_SCRUB_METAPATH subtype so that we can scrub the metadata
directory tree path to the refcount btree file for each rt group.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If we encounter a directory that has been configured to pass on a CoW
extent size hint to a new realtime file and the hint isn't an integer
multiple of the rt extent size, we should flag the hint for
administrative review and/or turn it off because that is a
misconfiguration.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Update the quota scrubber to allow dquots where the realtime block count
exceeds the block count of the rt volume if reflink is enabled.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If there's a gap between records in the rt refcount btree, we ought to
cross-reference the gap with the rtrmap records to make sure that there
aren't any overlapping records for a region that doesn't have any shared
ownership.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Allow overlapping realtime reverse mapping records if they both describe
shared data extents and the fs supports reflink on the realtime volume.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the realtime refcount btree to implement cross-reference checks in
other data structures.
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>
