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When we reserve a delalloc region in xfs_buffered_write_iomap_begin,
we mark the iomap as IOMAP_F_NEW so that the the write context
understands that it allocated the delalloc region.
If we then fail that buffered write, xfs_buffered_write_iomap_end()
checks for the IOMAP_F_NEW flag and if it is set, it punches out
the unused delalloc region that was allocated for the write.
The assumption this code makes is that all buffered write operations
that can allocate space are run under an exclusive lock (i_rwsem).
This is an invalid assumption: page faults in mmap()d regions call
through this same function pair to map the file range being faulted
and this runs only holding the inode->i_mapping->invalidate_lock in
shared mode.
IOWs, we can have races between page faults and write() calls that
fail the nested page cache write operation that result in data loss.
That is, the failing iomap_end call will punch out the data that
the other racing iomap iteration brought into the page cache. This
can be reproduced with generic/34[46] if we arbitrarily fail page
cache copy-in operations from write() syscalls.
Code analysis tells us that the iomap_page_mkwrite() function holds
the already instantiated and uptodate folio locked across the iomap
mapping iterations. Hence the folio cannot be removed from memory
whilst we are mapping the range it covers, and as such we do not
care if the mapping changes state underneath the iomap iteration
loop:
1. if the folio is not already dirty, there is no writeback races
possible.
2. if we allocated the mapping (delalloc or unwritten), the folio
cannot already be dirty. See #1.
3. If the folio is already dirty, it must be up to date. As we hold
it locked, it cannot be reclaimed from memory. Hence we always
have valid data in the page cache while iterating the mapping.
4. Valid data in the page cache can exist when the underlying
mapping is DELALLOC, UNWRITTEN or WRITTEN. Having the mapping
change from DELALLOC->UNWRITTEN or UNWRITTEN->WRITTEN does not
change the data in the page - it only affects actions if we are
initialising a new page. Hence #3 applies and we don't care
about these extent map transitions racing with
iomap_page_mkwrite().
5. iomap_page_mkwrite() checks for page invalidation races
(truncate, hole punch, etc) after it locks the folio. We also
hold the mapping->invalidation_lock here, and hence the mapping
cannot change due to extent removal operations while we are
iterating the folio.
As such, filesystems that don't use bufferheads will never fail
the iomap_folio_mkwrite_iter() operation on the current mapping,
regardless of whether the iomap should be considered stale.
Further, the range we are asked to iterate is limited to the range
inside EOF that the folio spans. Hence, for XFS, we will only map
the exact range we are asked for, and we will only do speculative
preallocation with delalloc if we are mapping a hole at the EOF
page. The iterator will consume the entire range of the folio that
is within EOF, and anything beyond the EOF block cannot be accessed.
We never need to truncate this post-EOF speculative prealloc away in
the context of the iomap_page_mkwrite() iterator because if it
remains unused we'll remove it when the last reference to the inode
goes away.
Hence we don't actually need an .iomap_end() cleanup/error handling
path at all for iomap_page_mkwrite() for XFS. This means we can
separate the page fault processing from the complexity of the
.iomap_end() processing in the buffered write path. This also means
that the buffered write path will also be able to take the
mapping->invalidate_lock as necessary.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
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The kernel robot complained about this:
>> fs/xfs/xfs_file.c:1266:31: sparse: sparse: incorrect type in return expression (different base types) @@ expected int @@ got restricted vm_fault_t @@
fs/xfs/xfs_file.c:1266:31: sparse: expected int
fs/xfs/xfs_file.c:1266:31: sparse: got restricted vm_fault_t
fs/xfs/xfs_file.c:1314:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted vm_fault_t [usertype] ret @@ got int @@
fs/xfs/xfs_file.c:1314:21: sparse: expected restricted vm_fault_t [usertype] ret
fs/xfs/xfs_file.c:1314:21: sparse: got int
Fix the incorrect return type for these two functions.
While we're at it, make the !fsdax version return VM_FAULT_SIGBUS
because a zero return value will cause some callers to try to lock
vmf->page, which we never set here.
Fixes: ea6c49b784f0 ("xfs: support CoW in fsdax mode")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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Pull more xfs updates from Darrick Wong:
"There's not a lot this time around, just the usual bug fixes and
corrections for missing error returns.
- Return error codes from block device flushes to userspace
- Fix a deadlock between reclaim and mount time quotacheck
- Fix an unnecessary ENOSPC return when doing COW on a filesystem
with severe free space fragmentation
- Fix a miscalculation in the transaction reservation computations
for file removal operations"
* tag 'xfs-5.20-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix inode reservation space for removing transaction
xfs: Fix false ENOSPC when performing direct write on a delalloc extent in cow fork
xfs: fix intermittent hang during quotacheck
xfs: check return codes when flushing block devices
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If a blkdev_issue_flush fails, fsync needs to report that to upper
levels. Modify xfs_file_fsync to capture the errors, while trying to
flush as much data and log updates to disk as possible.
If log writes cannot flush the data device, we need to shut down the log
immediately because we've violated a log invariant. Modify this code to
check the return value of blkdev_issue_flush as well.
This behavior seems to go back to about 2.6.15 or so, which makes this
fixes tag a bit misleading.
Link: https://elixir.bootlin.com/linux/v2.6.15/source/fs/xfs/xfs_vnodeops.c#L1187
Fixes: b5071ada510a ("xfs: remove xfs_blkdev_issue_flush")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
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This adds the async buffered write support to XFS. For async buffered
write requests, the request will return -EAGAIN if the ilock cannot be
obtained immediately.
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-15-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files who
are going to be deduped. After that, call compare range function only
when files are both DAX or not.
Link: https://lkml.kernel.org/r/20220603053738.1218681-15-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In fsdax mode, WRITE and ZERO on a shared extent need CoW performed.
After that, new allocated extents needs to be remapped to the file. So,
add a CoW identification in ->iomap_begin(), and implement ->iomap_end()
to do the remapping work.
[akpm@linux-foundation.org: make xfs_dax_fault() static]
Link: https://lkml.kernel.org/r/20220603053738.1218681-14-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull more xfs updates from Dave Chinner:
"This update is largely bug fixes and cleanups for all the code merged
in the first pull request. The majority of them are to the new logged
attribute code, but there are also a couple of fixes for other log
recovery and memory leaks that have recently been found.
Summary:
- fix refcount leak in xfs_ifree()
- fix xfs_buf_cancel structure leaks in log recovery
- fix dquot leak after failed quota check
- fix a couple of problematic ASSERTS
- fix small aim7 perf regression in from new btree sibling validation
- clean up log incompat feature marking for new logged attribute
feature
- disallow logged attributes on legacy V4 filesystem formats.
- fix da state leak when freeing attr intents
- improve validation of the attr log items in recovery
- use slab caches for commonly used attr structures
- fix leaks of attr name/value buffer and reduce copying overhead
during intent logging
- remove some dead debug code from log recovery"
* tag 'xfs-5.19-for-linus-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (33 commits)
xfs: fix xfs_ifree() error handling to not leak perag ref
xfs: move xfs_attr_use_log_assist usage out of libxfs
xfs: move xfs_attr_use_log_assist out of xfs_log.c
xfs: warn about LARP once per mount
xfs: implement per-mount warnings for scrub and shrink usage
xfs: don't log every time we clear the log incompat flags
xfs: convert buf_cancel_table allocation to kmalloc_array
xfs: don't leak xfs_buf_cancel structures when recovery fails
xfs: refactor buffer cancellation table allocation
xfs: don't leak btree cursor when insrec fails after a split
xfs: purge dquots after inode walk fails during quotacheck
xfs: assert in xfs_btree_del_cursor should take into account error
xfs: don't assert fail on perag references on teardown
xfs: avoid unnecessary runtime sibling pointer endian conversions
xfs: share xattr name and value buffers when logging xattr updates
xfs: do not use logged xattr updates on V4 filesystems
xfs: Remove duplicate include
xfs: reduce IOCB_NOWAIT judgment for retry exclusive unaligned DIO
xfs: Remove dead code
xfs: fix typo in comment
...
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Pull xfs updates from Dave Chinner:
"This is a big update with lots of new code. The summary below them
all, so I'll just touch on teh higlights. The two main new features
are Large Extent Counts and Logged Attribute Replay - these are two
new foundational features that we are building more complex future
features on top of.
For upcoming functionality, we need to be able to store hundreds of
millions of xattrs per inode. The Large Extent Count feature removes
the limits that prevent this scale of xattr storage, and while we were
modifying the on disk extent count format we also increased the number
of data extents we support per inode from 2^32 to 2^47.
We also need to be able to modify xattrs as part of larger atomic
transactions rather than as standalone transactions. The Logged
Attribute Replay feature introduces the infrastructure that allows us
to use intents to record the attribute modifications in the journal
before we start them, hence allowing other atomic transactions to log
attribute modification intents and then defer the actual modification
to later. If we then crash, log recovery then guarantees that the
attribute is replayed in the context of the atomic transaction that
logged the intent.
A significant chunk of the commits in this merge are for the base
attribute replay functionality along with fixes, improvements and
cleanups related to this new functioanlity. Allison deserves a big
round of thanks for her ongoing work to get this functionality into
XFS.
There are also many other smaller changes and improvements, so overall
this is one of the bigger XFS merge requests in some time.
I will be following up next week with another smaller pull request -
we already have another round of fixes and improvements to the logged
attribute replay functionality just about ready to go. They'll soak
and test over the next week, and I'll send a pull request for them
near the end of the merge window.
Summary:
- support for printk message indexing.
- large extent counts to provide support for up to 2^47 data extents
and 2^32 attribute extents, allowing us to scale beyond 4 billion
data extents to billions of xattrs per inode.
- conversion of various flags fields to be consistently declared as
unsigned bit fields.
- improvements to realtime extent accounting and converts them to
per-cpu counters to match all the other block and inode accounting.
- reworks core log formatting code to reduce iterations, have a
shorter, cleaner fast path and generally be easier to understand
and maintain.
- improvements to rmap btree searches that reduce overhead by up to
30% resulting in xfs_scrub runtime reductions of 15%.
- improvements to reflink that remove the size limitations in
remapping operations and greatly reduce the size of transaction
reservations.
- reworks the minimum log size calculations to allow us to change
transaction reservations without changing the minimum supported log
size.
- removal of quota warning support as it has never been used on
Linux.
- intent whiteouts to allow us to cancel intents that are completed
entirely in memory rather than having use CPU and disk bandwidth
formatting and writing them into the journal when it is not
necessary. This makes rmap, reflink and extent freeing slightly
more efficient, but provides massive improvements for....
- Logged Attribute Replay feature support. This is a fundamental
change to the way we modify attributes, laying the foundation for
future integration of attribute modifications as part of other
atomic transactional operations the filesystem performs.
- Lots of cleanups and fixes for the logged attribute replay
functionality"
* tag 'xfs-5.19-for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (124 commits)
xfs: can't use kmem_zalloc() for attribute buffers
xfs: detect empty attr leaf blocks in xfs_attr3_leaf_verify
xfs: ATTR_REPLACE algorithm with LARP enabled needs rework
xfs: use XFS_DA_OP flags in deferred attr ops
xfs: remove xfs_attri_remove_iter
xfs: switch attr remove to xfs_attri_set_iter
xfs: introduce attr remove initial states into xfs_attr_set_iter
xfs: xfs_attr_set_iter() does not need to return EAGAIN
xfs: clean up final attr removal in xfs_attr_set_iter
xfs: remote xattr removal in xfs_attr_set_iter() is conditional
xfs: XFS_DAS_LEAF_REPLACE state only needed if !LARP
xfs: split remote attr setting out from replace path
xfs: consolidate leaf/node states in xfs_attr_set_iter
xfs: kill XFS_DAC_LEAF_ADDNAME_INIT
xfs: separate out initial attr_set states
xfs: don't set quota warning values
xfs: remove warning counters from struct xfs_dquot_res
xfs: remove quota warning limit from struct xfs_quota_limits
xfs: rework deferred attribute operation setup
xfs: make xattri_leaf_bp more useful
...
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Retry unaligned DIO with exclusive blocking semantics only when the
IOCB_NOWAIT flag is not set. If we are doing nonblocking user I/O,
propagate the error directly.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Allow the file system to keep state for all iterations. For now only
wire it up for direct I/O as there is an immediate need for it there.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Get the struct inode pointer from iocb->ki_filp->f_mapping->host
directly and the other variables are unnecessary, so simplify the
local variables assignment.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Remove the open-coded check of O_LARGEFILE. This changes the errno
to be the same as other filesystems; it was changed generically in
2.6.24 but that fix skipped XFS.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Since we've started treating fallocate more like a file write, we
should flush the log to disk if the user has asked for synchronous
writes either by setting it via fcntl flags, or inode flags, or with
the sync mount option. We've already got a helper for this, so use
it.
[The original patch by Darrick was massaged by Dave to fit this patchset]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
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The operations that xfs_update_prealloc_flags() perform are now
unique to xfs_fs_map_blocks(), so move xfs_update_prealloc_flags()
to be a static function in xfs_pnfs.c and cut out all the
other functionality that is doesn't use anymore.
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>
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Now that we only call xfs_update_prealloc_flags() from
xfs_file_fallocate() in the case where we need to set the
preallocation flag, do this in xfs_alloc_file_space() where we
already have the inode joined into a transaction and get
rid of the call to xfs_update_prealloc_flags() from the fallocate
code.
This also means that we now correctly avoid setting the
XFS_DIFLAG_PREALLOC flag when xfs_is_always_cow_inode() is true, as
these inodes will never have preallocated extents.
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>
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In XFS, we always update the inode change and modification time when
any fallocate() operation succeeds. Furthermore, as various
fallocate modes can change the file contents (extending EOF,
punching holes, zeroing things, shifting extents), we should drop
file privileges like suid just like we do for a regular write().
There's already a VFS helper that figures all this out for us, so
use that.
The net effect of this is that we no longer drop suid/sgid if the
caller is root, but we also now drop file capabilities.
We also move the xfs_update_prealloc_flags() function so that it now
is only called by the scope that needs to set the the prealloc flag.
Based on a patch from Darrick Wong.
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>
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Callers can acheive the same thing by calling xfs_log_force_inode()
after making their modifications. There is no need for
xfs_update_prealloc_flags() to do this.
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>
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Pull xfs irix ioctl housecleaning from Darrick Wong:
"Remove the XFS_IOC_ALLOCSP* and XFS_IOC_FREESP* ioctl families.
This is the second of a series of small pull requests that perform
some long overdue housecleaning of XFS ioctls. This time, we're
vacating the implementation of all variants of the ALLOCSP and FREESP
ioctls, which are holdovers from EFS in Irix, circa 1993. Roughly
equivalent functionality have been available for both ioctls since
2.6.25 (April 2008):
- XFS_IOC_FREESP ftruncates a file.
- XFS_IOC_ALLOCSP is the equivalent of fallocate.
As noted in the fix patch for CVE 2021-4155, the ALLOCSP ioctl has
been serving up stale disk blocks since 2000, and in 21 years
**nobody** noticed. On those grounds I think it's safe to vacate the
implementation.
Note that we lose the ability to preallocate and truncate relative to
the current file position, but as nobody's ever implemented that for
the VFS, I conclude that it's not in high demand.
Linux has always used fallocate as the space management system call,
whereas these Irix legacy ioctls only ever worked on XFS, and have
been the cause of recent stale data disclosure vulnerabilities. As
equivalent functionality is available elsewhere, remove the code"
* tag 'xfs-5.17-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: kill the XFS_IOC_{ALLOC,FREE}SP* ioctls
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According to the glibc compat header for Irix 4, these ioctls originated
in April 1991 as a (somewhat clunky) way to preallocate space at the end
of a file on an EFS filesystem. XFS, which was released in Irix 5.3 in
December 1993, picked up these ioctls to maintain compatibility and they
were ported to Linux in the early 2000s.
Recently it was pointed out to me they still lurk in the kernel, even
though the Linux fallocate syscall supplanted the functionality a long
time ago. fstests doesn't seem to include any real functional or stress
tests for these ioctls, which means that the code quality is ... very
questionable. Most notably, it was a stale disk block exposure vector
for 21 years and nobody noticed or complained. As mature programmers
say, "If you're not testing it, it's broken."
Given all that, let's withdraw these ioctls from the XFS userspace API.
Normally we'd set a long deprecation process, but I estimate that there
aren't any real users, so let's trigger a warning in dmesg and return
-ENOTTY.
See: CVE-2021-4155
Augments: 983d8e60f508 ("xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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Add helpers to prepare for using different DAX operations.
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
[hch: split from a larger patch + slight cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-16-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher:
"Functions gfs2_file_read_iter and gfs2_file_write_iter are both
accessing the user buffer to write to or read from while holding the
inode glock.
In the most basic deadlock scenario, that buffer will not be resident
and it will be mapped to the same file. Accessing the buffer will
trigger a page fault, and gfs2 will deadlock trying to take the same
inode glock again while trying to handle that fault.
Fix that and similar, more complex scenarios by disabling page faults
while accessing user buffers. To make this work, introduce a small
amount of new infrastructure and fix some bugs that didn't trigger so
far, with page faults enabled"
* tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fix mmap + page fault deadlocks for direct I/O
iov_iter: Introduce nofault flag to disable page faults
gup: Introduce FOLL_NOFAULT flag to disable page faults
iomap: Add done_before argument to iomap_dio_rw
iomap: Support partial direct I/O on user copy failures
iomap: Fix iomap_dio_rw return value for user copies
gfs2: Fix mmap + page fault deadlocks for buffered I/O
gfs2: Eliminate ip->i_gh
gfs2: Move the inode glock locking to gfs2_file_buffered_write
gfs2: Introduce flag for glock holder auto-demotion
gfs2: Clean up function may_grant
gfs2: Add wrapper for iomap_file_buffered_write
iov_iter: Introduce fault_in_iov_iter_writeable
iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
powerpc/kvm: Fix kvm_use_magic_page
iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value
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Add a done_before argument to iomap_dio_rw that indicates how much of
the request has already been transferred. When the request succeeds, we
report that done_before additional bytes were tranferred. This is
useful for finishing a request asynchronously when part of the request
has already been completed synchronously.
We'll use that to allow iomap_dio_rw to be used with page faults
disabled: when a page fault occurs while submitting a request, we
synchronously complete the part of the request that has already been
submitted. The caller can then take care of the page fault and call
iomap_dio_rw again for the rest of the request, passing in the number of
bytes already tranferred.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
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Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.
Polling for the bio itself leads to a few advantages:
- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull xfs updates from Darrick Wong:
"There's a lot in this cycle.
Starting with bug fixes: To avoid livelocks between the logging code
and the quota code, we've disabled the ability of quotaoff to turn off
quota accounting. (Admins can still disable quota enforcement, but
truly turning off accounting requires a remount.) We've tried to do
this in a careful enough way that there shouldn't be any user visible
effects aside from quotaoff no longer randomly hanging the system.
We've also fixed some bugs in runtime log behavior that could trip up
log recovery if (otherwise unrelated) transactions manage to start and
commit concurrently; some bugs in the GETFSMAP ioctl where we would
incorrectly restrict the range of records output if the two xfs
devices are of different sizes; a bug that resulted in fallocate
funshare failing unnecessarily; and broken behavior in the xfs inode
cache when DONTCACHE is in play.
As for new features: we now batch inode inactivations in percpu
background threads, which sharply decreases frontend thread wait time
when performing file deletions and should improve overall directory
tree deletion times. This eliminates both the problem where closing an
unlinked file (especially on a frozen fs) can stall for a long time,
and should also ease complaints about direct reclaim bogging down on
unlinked file cleanup.
Starting with this release, we've enabled pipelining of the XFS log.
On workloads with high rates of metadata updates to different shards
of the filesystem, multiple threads can be used to format committed
log updates into log checkpoints.
Lastly, with this release, two new features have graduated to
supported status: inode btree counters (for faster mounts), and
support for dates beyond Y2038. Expect these to be enabled by default
in a future release of xfsprogs.
Summary:
- Fix a potential log livelock on busy filesystems when there's so
much work going on that we can't finish a quotaoff before filling
up the log by removing the ability to disable quota accounting.
- Introduce the ability to use per-CPU data structures in XFS so that
we can do a better job of maintaining CPU locality for certain
operations.
- Defer inode inactivation work to per-CPU lists, which will help us
batch that processing. Deletions of large sparse files will
*appear* to run faster, but all that means is that we've moved the
work to the backend.
- Drop the EXPERIMENTAL warnings from the y2038+ support and the
inode btree counters, since it's been nearly a year and no
complaints have come in.
- Remove more of our bespoke kmem* variants in favor of using the
standard Linux calls.
- Prepare for the addition of log incompat features in upcoming
cycles by actually adding code to support this.
- Small cleanups of the xattr code in preparation for landing support
for full logging of extended attribute updates in a future cycle.
- Replace the various log shutdown state and flag code all over xfs
with a single atomic bit flag.
- Fix a serious log recovery bug where log item replay can be skipped
based on the start lsn of a transaction even though the transaction
commit lsn is the key data point for that by enforcing start lsns
to appear in the log in the same order as commit lsns.
- Enable pipelining in the code that pushes log items to disk.
- Drop ->writepage.
- Fix some bugs in GETFSMAP where the last fsmap record reported for
a device could extend beyond the end of the device, and a separate
bug where query keys for one device could be applied to another.
- Don't let GETFSMAP query functions edit their input parameters.
- Small cleanups to the scrub code's handling of perag structures.
- Small cleanups to the incore inode tree walk code.
- Constify btree function parameters that aren't changed, so that
there will never again be confusion about range query functions
changing their input parameters.
- Standardize the format and names of tracepoint data attributes.
- Clean up all the mount state and feature flags to use wrapped
bitset functions instead of inconsistently open-coded flag checks.
- Fix some confusion between xfs_buf hash table key variable vs.
block number.
- Fix a mis-interaction with iomap where we reported shared delalloc
cow fork extents to iomap, which would cause the iomap unshare
operation to return IO errors unnecessarily.
- Fix DONTCACHE behavior"
* tag 'xfs-5.15-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (103 commits)
xfs: fix I_DONTCACHE
xfs: only set IOMAP_F_SHARED when providing a srcmap to a write
xfs: fix perag structure refcounting error when scrub fails
xfs: rename buffer cache index variable b_bn
xfs: convert bp->b_bn references to xfs_buf_daddr()
xfs: introduce xfs_buf_daddr()
xfs: kill xfs_sb_version_has_v3inode()
xfs: introduce xfs_sb_is_v5 helper
xfs: remove unused xfs_sb_version_has wrappers
xfs: convert xfs_sb_version_has checks to use mount features
xfs: convert scrub to use mount-based feature checks
xfs: open code sb verifier feature checks
xfs: convert xfs_fs_geometry to use mount feature checks
xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown
xfs: convert remaining mount flags to state flags
xfs: convert mount flags to features
xfs: consolidate mount option features in m_features
xfs: replace xfs_sb_version checks with feature flag checks
xfs: reflect sb features in xfs_mount
xfs: rework attr2 feature and mount options
...
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Remove the shouty macro and instead use the inline function that
matches other state/feature check wrapper naming. This conversion
was done with sed.
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>
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Replace m_flags feature checks with xfs_has_<feature>() calls and
rework the setup code to set flags in m_features.
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>
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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>
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Use invalidate_lock instead of XFS internal i_mmap_lock. The intended
purpose of invalidate_lock is exactly the same. Note that the locking in
__xfs_filemap_fault() slightly changes as filemap_fault() already takes
invalidate_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
CC: <linux-xfs@vger.kernel.org>
CC: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
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Pull xfs updates from Darrick Wong:
"Most of the work this cycle has been on refactoring various parts of
the codebase. The biggest non-cleanup changes are (1) reducing the
number of cache flushes sent when writing the log; (2) a substantial
number of log recovery fixes; and (3) I started accepting pull
requests from contributors if the commits in their branches match
what's been sent to the list.
For a week or so I /had/ staged a major cleanup of the logging code
from Dave Chinner, but it exposed so many lurking bugs in other parts
of the logging and log recovery code that I decided to defer that
patchset until we can address those latent bugs.
Larger cleanups this time include walking the incore inode cache (me)
and rework of the extended attribute code (Allison) to prepare it for
adding logged xattr updates (and directory tree parent pointers) in
future releases.
Summary:
- Refactor the buffer cache to use bulk page allocation
- Convert agnumber-based AG iteration to walk per-AG structures
- Clean up some unit conversions and other code warts
- Reduce spinlock contention in the directio fastpath
- Collapse all the inode cache walks into a single function
- Remove indirect function calls from the inode cache walk code
- Dramatically reduce the number of cache flushes sent when writing
log buffers
- Preserve inode sickness reports for longer
- Rename xfs_eofblocks since it controls inode cache walks
- Refactor the extended attribute code to prepare it for the addition
of log intent items to make xattrs fully transactional
- A few fixes to earlier large patchsets
- Log recovery fixes so that we don't accidentally mark the log clean
when log intent recovery fails
- Fix some latent SOB errors
- Clean up shutdown messages that get logged to dmesg
- Fix a regression in the online shrink code
- Fix a UAF in the buffer logging code if the fs goes offline
- Fix uninitialized error variables
- Fix a UAF in the CIL when commited log item callbacks race with a
shutdown
- Fix a bug where the CIL could hang trying to push part of the log
ring buffer that hasn't been filled yet"
* tag 'xfs-5.14-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (102 commits)
xfs: don't wait on future iclogs when pushing the CIL
xfs: Fix a CIL UAF by getting get rid of the iclog callback lock
xfs: remove callback dequeue loop from xlog_state_do_iclog_callbacks
xfs: don't nest icloglock inside ic_callback_lock
xfs: Initialize error in xfs_attr_remove_iter
xfs: fix endianness issue in xfs_ag_shrink_space
xfs: remove dead stale buf unpin handling code
xfs: hold buffer across unpin and potential shutdown processing
xfs: force the log offline when log intent item recovery fails
xfs: fix log intent recovery ENOSPC shutdowns when inactivating inodes
xfs: shorten the shutdown messages to a single line
xfs: print name of function causing fs shutdown instead of hex pointer
xfs: fix type mismatches in the inode reclaim functions
xfs: separate primary inode selection criteria in xfs_iget_cache_hit
xfs: refactor the inode recycling code
xfs: add iclog state trace events
xfs: xfs_log_force_lsn isn't passed a LSN
xfs: Fix CIL throttle hang when CIL space used going backwards
xfs: journal IO cache flush reductions
xfs: remove need_start_rec parameter from xlog_write()
...
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In doing an investigation into AIL push stalls, I was looking at the
log force code to see if an async CIL push could be done instead.
This lead me to xfs_log_force_lsn() and looking at how it works.
xfs_log_force_lsn() is only called from inode synchronisation
contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn
value as the LSN to sync the log to. This gets passed to
xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the
journal, and then used by xfs_log_force_lsn() to flush the iclogs to
the journal.
The problem is that ip->i_itemp->ili_last_lsn does not store a
log sequence number. What it stores is passed to it from the
->iop_committing method, which is called by xfs_log_commit_cil().
The value this passes to the iop_committing method is the CIL
context sequence number that the item was committed to.
As it turns out, xlog_cil_force_lsn() converts the sequence to an
actual commit LSN for the related context and returns that to
xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn"
variable that contained a sequence with an actual LSN and then uses
that to sync the iclogs.
This caused me some confusion for a while, even though I originally
wrote all this code a decade ago. ->iop_committing is only used by
a couple of log item types, and only inode items use the sequence
number it is passed.
Let's clean up the API, CIL structures and inode log item to call it
a sequence number, and make it clear that the high level code is
using CIL sequence numbers and not on-disk LSNs for integrity
synchronisation purposes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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It's a one line wrapper around blkdev_issue_flush(). Just replace it
with direct calls to blkdev_issue_flush().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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The xfs_eofblocks structure is no longer well-named -- nowadays it
provides optional filtering criteria to any walk of the incore inode
cache. Only one of the cache walk goals has anything to do with
clearing of speculative post-EOF preallocations, so change the name to
be more appropriate.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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In preparation for renaming struct xfs_eofblocks to struct xfs_icwalk,
change the prefix of the existing XFS_EOF_FLAGS_* flags to
XFS_ICWALK_FLAG_ and convert all the existing users. This adds a degree
of interface separation between the ioctl definitions and the incore
parameters. Since FLAGS_UNION is only used in xfs_icache.c, move it
there as a private flag.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
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Because this happens at high thread counts on high IOPS devices
doing mixed read/write AIO-DIO to a single file at about a million
iops:
64.09% 0.21% [kernel] [k] io_submit_one
- 63.87% io_submit_one
- 44.33% aio_write
- 42.70% xfs_file_write_iter
- 41.32% xfs_file_dio_write_aligned
- 25.51% xfs_file_write_checks
- 21.60% _raw_spin_lock
- 21.59% do_raw_spin_lock
- 19.70% __pv_queued_spin_lock_slowpath
This also happens of the IO completion IO path:
22.89% 0.69% [kernel] [k] xfs_dio_write_end_io
- 22.49% xfs_dio_write_end_io
- 21.79% _raw_spin_lock
- 20.97% do_raw_spin_lock
- 20.10% __pv_queued_spin_lock_slowpath
IOWs, fio is burning ~14 whole CPUs on this spin lock.
So, do an unlocked check against inode size first, then if we are
at/beyond EOF, take the spinlock and recheck. This makes the
spinlock disappear from the overwrite fastpath.
I'd like to report that fixing this makes things go faster. It
doesn't - it just exposes the the XFS_ILOCK as the next severe
contention point doing extent mapping lookups, and that now burns
all the 14 CPUs this spinlock was burning.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
|
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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>
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In preparation of removing the historic icinode struct, move the flags2
field into the containing xfs_inode structure.
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>
|
|
In preparation of removing the historic icinode struct, move the flags
field into the containing xfs_inode structure.
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>
|
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In preparation of removing the historic icinode struct, move the
cowextsize field into the containing xfs_inode structure. Also
switch to use the xfs_extlen_t instead of a uint32_t.
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>
|
|
In preparation of removing the historic icinode struct, move the on-disk
size field into the containing xfs_inode structure.
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>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
- vDSO build improvements including support for building with BSD.
- Cleanup to the AMU support code and initialisation rework to support
cpufreq drivers built as modules.
- Removal of synthetic frame record from exception stack when entering
the kernel from EL0.
- Add support for the TRNG firmware call introduced by Arm spec
DEN0098.
- Cleanup and refactoring across the board.
- Avoid calling arch_get_random_seed_long() from
add_interrupt_randomness()
- Perf and PMU updates including support for Cortex-A78 and the v8.3
SPE extensions.
- Significant steps along the road to leaving the MMU enabled during
kexec relocation.
- Faultaround changes to initialise prefaulted PTEs as 'old' when
hardware access-flag updates are supported, which drastically
improves vmscan performance.
- CPU errata updates for Cortex-A76 (#1463225) and Cortex-A55
(#1024718)
- Preparatory work for yielding the vector unit at a finer granularity
in the crypto code, which in turn will one day allow us to defer
softirq processing when it is in use.
- Support for overriding CPU ID register fields on the command-line.
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits)
drivers/perf: Replace spin_lock_irqsave to spin_lock
mm: filemap: Fix microblaze build failure with 'mmu_defconfig'
arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+
arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line
arm64: Defer enabling pointer authentication on boot core
arm64: cpufeatures: Allow disabling of BTI from the command-line
arm64: Move "nokaslr" over to the early cpufeature infrastructure
KVM: arm64: Document HVC_VHE_RESTART stub hypercall
arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0
arm64: Add an aliasing facility for the idreg override
arm64: Honor VHE being disabled from the command-line
arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line
arm64: cpufeature: Add an early command-line cpufeature override facility
arm64: Extract early FDT mapping from kaslr_early_init()
arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding()
arm64: cpufeature: Add global feature override facility
arm64: Move SCTLR_EL1 initialisation to EL-agnostic code
arm64: Simplify init_el2_state to be non-VHE only
arm64: Move VHE-specific SPE setup to mutate_to_vhe()
arm64: Drop early setting of MDSCR_EL2.TPMS
...
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|
Pull xfs updates from Darrick Wong:
"There's a lot going on this time, which seems about right for this
drama-filled year.
Community developers added some code to speed up freezing when
read-only workloads are still running, refactored the logging code,
added checks to prevent file extent counter overflow, reduced iolock
cycling to speed up fsync and gc scans, and started the slow march
towards supporting filesystem shrinking.
There's a huge refactoring of the internal speculative preallocation
garbage collection code which fixes a bunch of bugs, makes the gc
scheduling per-AG and hence multithreaded, and standardizes the retry
logic when we try to reserve space or quota, can't, and want to
trigger a gc scan. We also enable multithreaded quotacheck to reduce
mount times further. This is also preparation for background file gc,
which may or may not land for 5.13.
We also fixed some deadlocks in the rename code, fixed a quota
accounting leak when FSSETXATTR fails, restored the behavior that
write faults to an mmap'd region actually cause a SIGBUS, fixed a bug
where sgid directory inheritance wasn't quite working properly, and
fixed a bug where symlinks weren't working properly in ecryptfs. We
also now advertise the inode btree counters feature that was
introduced two cycles ago.
Summary:
- Fix an ABBA deadlock when renaming files on overlayfs.
- Make sure that we can't overflow the inode extent counters when
adding to or removing extents from a file.
- Make directory sgid inheritance work the same way as all the other
filesystems.
- Don't drain the buffer cache on freeze and ro remount, which should
reduce the amount of time if read-only workloads are continuing
during the freeze.
- Fix a bug where symlink size isn't reported to the vfs in ecryptfs.
- Disentangle log cleaning from log covering. This refactoring sets
us up for future changes to the log, though for now it simply means
that we can use covering for freezes, and cleaning becomes
something we only do at unmount.
- Speed up file fsyncs by reducing iolock cycling.
- Fix delalloc blocks leaking when changing the project id fails
because of input validation errors in FSSETXATTR.
- Fix oversized quota reservation when converting unwritten extents
during a DAX write.
- Create a transaction allocation helper function to standardize the
idiom of allocating a transaction, reserving blocks, locking
inodes, and reserving quota. Replace all the open-coded logic for
file creation, file ownership changes, and file modifications to
use them.
- Actually shut down the fs if the incore quota reservations get
corrupted.
- Fix background block garbage collection scans to not block and to
actually clean out CoW staging extents properly.
- Run block gc scans when we run low on project quota.
- Use the standardized transaction allocation helpers to make it so
that ENOSPC and EDQUOT errors during reservation will back out,
invoke the block gc scanner, and try again. This is preparation for
introducing background inode garbage collection in the next cycle.
- Combine speculative post-EOF block garbage collection with
speculative copy on write block garbage collection.
- Enable multithreaded quotacheck.
- Allow sysadmins to tweak the CPU affinities and maximum concurrency
levels of quotacheck and background blockgc worker pools.
- Expose the inode btree counter feature in the fs geometry ioctl.
- Cleanups of the growfs code in preparation for starting work on
filesystem shrinking.
- Fix all the bloody gcc warnings that the maintainer knows about. :P
- Fix a RST syntax error.
- Don't trigger bmbt corruption assertions after the fs shuts down.
- Restore behavior of forcing SIGBUS on a shut down filesystem when
someone triggers a mmap write fault (or really, any buffered
write)"
* tag 'xfs-5.12-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (85 commits)
xfs: consider shutdown in bmapbt cursor delete assert
xfs: fix boolreturn.cocci warnings
xfs: restore shutdown check in mapped write fault path
xfs: fix rst syntax error in admin guide
xfs: fix incorrect root dquot corruption error when switching group/project quota types
xfs: get rid of xfs_growfs_{data,log}_t
xfs: rename `new' to `delta' in xfs_growfs_data_private()
libxfs: expose inobtcount in xfs geometry
xfs: don't bounce the iolock between free_{eof,cow}blocks
xfs: expose the blockgc workqueue knobs publicly
xfs: parallelize block preallocation garbage collection
xfs: rename block gc start and stop functions
xfs: only walk the incore inode tree once per blockgc scan
xfs: consolidate the eofblocks and cowblocks workers
xfs: consolidate incore inode radix tree posteof/cowblocks tags
xfs: remove trivial eof/cowblocks functions
xfs: hide xfs_icache_free_cowblocks
xfs: hide xfs_icache_free_eofblocks
xfs: relocate the eofb/cowb workqueue functions
xfs: set WQ_SYSFS on all workqueues in debug mode
...
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|
In anticipation of more restructuring of the eof/cowblocks gc code,
refactor calling of those two functions into a single internal helper
function, then present a new standard interface to purge speculative
block preallocations and start shifting higher level code to use that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
|
|
Change the signature of xfs_blockgc_free_quota in preparation for the
next few patches. Callers can now pass EOF_FLAGS into the function to
control scan parameters; and the function will now pass back any
corruption errors seen while scanning, though for our retry loops we'll
just try again unconditionally.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
|
|
Move this function further down in the file so that later cleanups won't
have to declare static functions. Change the name because we're about
to rework all the code that performs garbage collection of speculatively
allocated file blocks. No functional changes.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
|
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The functions to run an eof/cowblocks scan to try to reduce quota usage
are kind of a mess -- the logic repeatedly initializes an eofb structure
and there are logic bugs in the code that result in the cowblocks scan
never actually happening.
Replace all three functions with a single function that fills out an
eofb and runs both eof and cowblocks scans.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
|
