Commit Graph

224 Commits

Author SHA1 Message Date
Dave Chinner
498f0adbcd xfs: convert xfs_imap() to take a perag
Callers have referenced perags but they don't pass it into
xfs_imap() so it takes it's own reference. Fix that so we can change
inode allocation over to using active references.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:52 +11:00
Dave Chinner
368e2d09b4 xfs: rework the perag trace points to be perag centric
So that they all output the same information in the traces to make
debugging refcount issues easier.

This means that all the lookup/drop functions no longer need to use
the full memory barrier atomic operations (atomic*_return()) so
will have less overhead when tracing is off. The set/clear tag
tracepoints no longer abuse the reference count to pass the tag -
the tag being cleared is obvious from the _RET_IP_ that is recorded
in the trace point.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:52 +11:00
Dave Chinner
c4d5660afb xfs: active perag reference counting
We need to be able to dynamically remove instantiated AGs from
memory safely, either for shrinking the filesystem or paging AG
state in and out of memory (e.g. supporting millions of AGs). This
means we need to be able to safely exclude operations from accessing
perags while dynamic removal is in progress.

To do this, introduce the concept of active and passive references.
Active references are required for high level operations that make
use of an AG for a given operation (e.g. allocation) and pin the
perag in memory for the duration of the operation that is operating
on the perag (e.g. transaction scope). This means we can fail to get
an active reference to an AG, hence callers of the new active
reference API must be able to handle lookup failure gracefully.

Passive references are used in low level code, where we might need
to access the perag structure for the purposes of completing high
level operations. For example, buffers need to use passive
references because:
- we need to be able to do metadata IO during operations like grow
  and shrink transactions where high level active references to the
  AG have already been blocked
- buffers need to pin the perag until they are reclaimed from
  memory, something that high level code has no direct control over.
- unused cached buffers should not prevent a shrink from being
  started.

Hence we have active references that will form exclusion barriers
for operations to be performed on an AG, and passive references that
will prevent reclaim of the perag until all objects with passive
references have been reclaimed themselves.

This patch introduce xfs_perag_grab()/xfs_perag_rele() as the API
for active AG reference functionality. We also need to convert the
for_each_perag*() iterators to use active references, which will
start the process of converting high level code over to using active
references. Conversion of non-iterator based code to active
references will be done in followup patches.

Note that the implementation using reference counting is really just
a development vehicle for the API to ensure we don't have any leaks
in the callers. Once we need to remove perag structures from memory
dyanmically, we will need a much more robust per-ag state transition
mechanism for preventing new references from being taken while we
wait for existing references to drain before removal from memory can
occur....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:42 +11:00
Wu Guanghao
4da112513c xfs: Fix deadlock on xfs_inodegc_worker
We are doing a test about deleting a large number of files
when memory is low. A deadlock problem was found.

[ 1240.279183] -> #1 (fs_reclaim){+.+.}-{0:0}:
[ 1240.280450]        lock_acquire+0x197/0x460
[ 1240.281548]        fs_reclaim_acquire.part.0+0x20/0x30
[ 1240.282625]        kmem_cache_alloc+0x2b/0x940
[ 1240.283816]        xfs_trans_alloc+0x8a/0x8b0
[ 1240.284757]        xfs_inactive_ifree+0xe4/0x4e0
[ 1240.285935]        xfs_inactive+0x4e9/0x8a0
[ 1240.286836]        xfs_inodegc_worker+0x160/0x5e0
[ 1240.287969]        process_one_work+0xa19/0x16b0
[ 1240.289030]        worker_thread+0x9e/0x1050
[ 1240.290131]        kthread+0x34f/0x460
[ 1240.290999]        ret_from_fork+0x22/0x30
[ 1240.291905]
[ 1240.291905] -> #0 ((work_completion)(&gc->work)){+.+.}-{0:0}:
[ 1240.293569]        check_prev_add+0x160/0x2490
[ 1240.294473]        __lock_acquire+0x2c4d/0x5160
[ 1240.295544]        lock_acquire+0x197/0x460
[ 1240.296403]        __flush_work+0x6bc/0xa20
[ 1240.297522]        xfs_inode_mark_reclaimable+0x6f0/0xdc0
[ 1240.298649]        destroy_inode+0xc6/0x1b0
[ 1240.299677]        dispose_list+0xe1/0x1d0
[ 1240.300567]        prune_icache_sb+0xec/0x150
[ 1240.301794]        super_cache_scan+0x2c9/0x480
[ 1240.302776]        do_shrink_slab+0x3f0/0xaa0
[ 1240.303671]        shrink_slab+0x170/0x660
[ 1240.304601]        shrink_node+0x7f7/0x1df0
[ 1240.305515]        balance_pgdat+0x766/0xf50
[ 1240.306657]        kswapd+0x5bd/0xd20
[ 1240.307551]        kthread+0x34f/0x460
[ 1240.308346]        ret_from_fork+0x22/0x30
[ 1240.309247]
[ 1240.309247] other info that might help us debug this:
[ 1240.309247]
[ 1240.310944]  Possible unsafe locking scenario:
[ 1240.310944]
[ 1240.312379]        CPU0                    CPU1
[ 1240.313363]        ----                    ----
[ 1240.314433]   lock(fs_reclaim);
[ 1240.315107]                                lock((work_completion)(&gc->work));
[ 1240.316828]                                lock(fs_reclaim);
[ 1240.318088]   lock((work_completion)(&gc->work));
[ 1240.319203]
[ 1240.319203]  *** DEADLOCK ***
...
[ 2438.431081] Workqueue: xfs-inodegc/sda xfs_inodegc_worker
[ 2438.432089] Call Trace:
[ 2438.432562]  __schedule+0xa94/0x1d20
[ 2438.435787]  schedule+0xbf/0x270
[ 2438.436397]  schedule_timeout+0x6f8/0x8b0
[ 2438.445126]  wait_for_completion+0x163/0x260
[ 2438.448610]  __flush_work+0x4c4/0xa40
[ 2438.455011]  xfs_inode_mark_reclaimable+0x6ef/0xda0
[ 2438.456695]  destroy_inode+0xc6/0x1b0
[ 2438.457375]  dispose_list+0xe1/0x1d0
[ 2438.458834]  prune_icache_sb+0xe8/0x150
[ 2438.461181]  super_cache_scan+0x2b3/0x470
[ 2438.461950]  do_shrink_slab+0x3cf/0xa50
[ 2438.462687]  shrink_slab+0x17d/0x660
[ 2438.466392]  shrink_node+0x87e/0x1d40
[ 2438.467894]  do_try_to_free_pages+0x364/0x1300
[ 2438.471188]  try_to_free_pages+0x26c/0x5b0
[ 2438.473567]  __alloc_pages_slowpath.constprop.136+0x7aa/0x2100
[ 2438.482577]  __alloc_pages+0x5db/0x710
[ 2438.485231]  alloc_pages+0x100/0x200
[ 2438.485923]  allocate_slab+0x2c0/0x380
[ 2438.486623]  ___slab_alloc+0x41f/0x690
[ 2438.490254]  __slab_alloc+0x54/0x70
[ 2438.491692]  kmem_cache_alloc+0x23e/0x270
[ 2438.492437]  xfs_trans_alloc+0x88/0x880
[ 2438.493168]  xfs_inactive_ifree+0xe2/0x4e0
[ 2438.496419]  xfs_inactive+0x4eb/0x8b0
[ 2438.497123]  xfs_inodegc_worker+0x16b/0x5e0
[ 2438.497918]  process_one_work+0xbf7/0x1a20
[ 2438.500316]  worker_thread+0x8c/0x1060
[ 2438.504938]  ret_from_fork+0x22/0x30

When the memory is insufficient, xfs_inonodegc_worker will trigger memory
reclamation when memory is allocated, then flush_work() may be called to
wait for the work to complete. This causes a deadlock.

So use memalloc_nofs_save() to avoid triggering memory reclamation in
xfs_inodegc_worker.

Signed-off-by: Wu Guanghao <wuguanghao3@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-01-03 10:23:07 -08:00
Long Li
28b4b05963 xfs: fix incorrect i_nlink caused by inode racing
The following error occurred during the fsstress test:

XFS: Assertion failed: VFS_I(ip)->i_nlink >= 2, file: fs/xfs/xfs_inode.c, line: 2452

The problem was that inode race condition causes incorrect i_nlink to be
written to disk, and then it is read into memory. Consider the following
call graph, inodes that are marked as both XFS_IFLUSHING and
XFS_IRECLAIMABLE, i_nlink will be reset to 1 and then restored to original
value in xfs_reinit_inode(). Therefore, the i_nlink of directory on disk
may be set to 1.

  xfsaild
      xfs_inode_item_push
          xfs_iflush_cluster
              xfs_iflush
                  xfs_inode_to_disk

  xfs_iget
      xfs_iget_cache_hit
          xfs_iget_recycle
              xfs_reinit_inode
                  inode_init_always

xfs_reinit_inode() needs to hold the ILOCK_EXCL as it is changing internal
inode state and can race with other RCU protected inode lookups. On the
read side, xfs_iflush_cluster() grabs the ILOCK_SHARED while under rcu +
ip->i_flags_lock, and so xfs_iflush/xfs_inode_to_disk() are protected from
racing inode updates (during transactions) by that lock.

Fixes: ff7bebeb91 ("xfs: refactor the inode recycling code") # goes further back than this
Signed-off-by: Long Li <leo.lilong@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-21 10:00:01 -08:00
Jason A. Donenfeld
a251c17aa5 treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00
Linus Torvalds
6614a3c316 - 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
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYuravgAKCRDdBJ7gKXxA
 jpqSAQDrXSdII+ht9kSHlaCVYjqRFQz/rRvURQrWQV74f6aeiAD+NHHeDPwZn11/
 SPktqEUrF1pxnGQxqLh1kUFUhsVZQgE=
 =w/UH
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-08-03' of 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
  ...
2022-08-05 16:32:45 -07:00
Darrick J. Wong
c78c2d0903 xfs: don't leak memory when attr fork loading fails
I observed the following evidence of a memory leak while running xfs/399
from the xfs fsck test suite (edited for brevity):

XFS (sde): Metadata corruption detected at xfs_attr_shortform_verify_struct.part.0+0x7b/0xb0 [xfs], inode 0x1172 attr fork
XFS: Assertion failed: ip->i_af.if_u1.if_data == NULL, file: fs/xfs/libxfs/xfs_inode_fork.c, line: 315
------------[ cut here ]------------
WARNING: CPU: 2 PID: 91635 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 2 PID: 91635 Comm: xfs_scrub Tainted: G        W         5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Call Trace:
 <TASK>
 xfs_ifork_zap_attr+0x7c/0xb0
 xfs_iformat_attr_fork+0x86/0x110
 xfs_inode_from_disk+0x41d/0x480
 xfs_iget+0x389/0xd70
 xfs_bulkstat_one_int+0x5b/0x540
 xfs_bulkstat_iwalk+0x1e/0x30
 xfs_iwalk_ag_recs+0xd1/0x160
 xfs_iwalk_run_callbacks+0xb9/0x180
 xfs_iwalk_ag+0x1d8/0x2e0
 xfs_iwalk+0x141/0x220
 xfs_bulkstat+0x105/0x180
 xfs_ioc_bulkstat.constprop.0.isra.0+0xc5/0x130
 xfs_file_ioctl+0xa5f/0xef0
 __x64_sys_ioctl+0x82/0xa0
 do_syscall_64+0x2b/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

This newly-added assertion checks that there aren't any incore data
structures hanging off the incore fork when we're trying to reset its
contents.  From the call trace, it is evident that iget was trying to
construct an incore inode from the ondisk inode, but the attr fork
verifier failed and we were trying to undo all the memory allocations
that we had done earlier.

The three assertions in xfs_ifork_zap_attr check that the caller has
already called xfs_idestroy_fork, which clearly has not been done here.
As the zap function then zeroes the pointers, we've effectively leaked
the memory.

The shortest change would have been to insert an extra call to
xfs_idestroy_fork, but it makes more sense to bundle the _idestroy_fork
call into _zap_attr, since all other callsites call _idestroy_fork
immediately prior to calling _zap_attr.  IOWs, it eliminates one way to
fail.

Note: This change only applies cleanly to 2ed5b09b3e, since we just
reworked the attr fork lifetime.  However, I think this memory leak has
existed since 0f45a1b20c, since the chain xfs_iformat_attr_fork ->
xfs_iformat_local -> xfs_init_local_fork will allocate
ifp->if_u1.if_data, but if xfs_ifork_verify_local_attr fails,
xfs_iformat_attr_fork will free i_afp without freeing any of the stuff
hanging off i_afp.  The solution for older kernels I think is to add the
missing call to xfs_idestroy_fork just prior to calling kmem_cache_free.

Found by fuzzing a.sfattr.hdr.totsize = lastbit in xfs/399.

Fixes: 2ed5b09b3e ("xfs: make inode attribute forks a permanent part of struct xfs_inode")
Probably-Fixes: 0f45a1b20c ("xfs: improve local fork verification")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-07-20 16:40:39 -07:00
Darrick J. Wong
6d200bdc01 xfs: make attr forks permanent
This series fixes a use-after-free bug that syzbot uncovered.  The UAF
 itself is a result of a race condition between getxattr and removexattr
 because callers to getxattr do not necessarily take any sort of locks
 before calling into the filesystem.
 
 Although the race condition itself can be fixed through clever use of a
 memory barrier, further consideration of the use cases of extended
 attributes shows that most files always have at least one attribute, so
 we might as well make them permanent.
 
 v2: Minor tweaks suggested by Dave, and convert some more macros to
 helper functions.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmLQRsAACgkQ+H93GTRK
 tOseOw/+JdSH2MU2xx+XoE5M/fStzGpw0UsoOqDo8kUPKDt3z12NwuczlL4OAiuw
 XFrN/1IAnxBsTD9YxFYbqoCPNi/VR81ajfWV7JqD2B1Joj0aATsxGDdNUYJnxCdU
 HMlMqP5o77XvArwkxFbgxYi7UGdAeNwXxqUJcJ8FopQo2lb8+SG6XzpLgGKnyrKT
 FRNKXNObplhtzOs/Bv8qYAxJulmmjkktFJXhK2OAUJlIDjFwFY9Wo2T4QuOVe9w+
 NXFOYyu0BqWLpDZQkYKWoCnF0GNsUavS8DP6zZYW3qJ6mX/f1jmtfbOLAkHNhlh8
 uHy/3k3SeQhKztTqM28sPioe6mdj2xocorDCCVBgGXgWxVF6aWeM/PS4tMTWN/Bg
 TWd1egERpeVC0Ymkm0LTCIDNuLqxsknK1G6sxXhwrQ8cw/70Gl08ePwgdyZ6hpD9
 Q61iJQofcI7MJX189a2VSbbHRzFnZIA+uVK4oyhmdEkQVKTHgmzwHVP660oAv9bD
 Y5hqkWEoyKTaaCsOWRAPVXG3k03lq+TNcaGggZgwFx11Gw4oMEx5hMUztoP54xX4
 aEXb1HWcCmMxy8llnFY/82baW98ucwl8FwWF1qhNIPT40mYx9IobDmvkCtNrAoOC
 41U7O8CxxPlt7XKxoRhafQOAhzp0ZzuhCdbaFIUENV7pTAJtq5Q=
 =W3Ad
 -----END PGP SIGNATURE-----

Merge tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.20-mergeB

xfs: make attr forks permanent

This series fixes a use-after-free bug that syzbot uncovered.  The UAF
itself is a result of a race condition between getxattr and removexattr
because callers to getxattr do not necessarily take any sort of locks
before calling into the filesystem.

Although the race condition itself can be fixed through clever use of a
memory barrier, further consideration of the use cases of extended
attributes shows that most files always have at least one attribute, so
we might as well make them permanent.

v2: Minor tweaks suggested by Dave, and convert some more macros to
helper functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

* tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: replace inode fork size macros with functions
  xfs: replace XFS_IFORK_Q with a proper predicate function
  xfs: use XFS_IFORK_Q to determine the presence of an xattr fork
  xfs: make inode attribute forks a permanent part of struct xfs_inode
  xfs: convert XFS_IFORK_PTR to a static inline helper
2022-07-14 09:46:37 -07:00
Dave Chinner
fad743d7cd xfs: add log item precommit operation
For inodes that are dirty, we have an attached cluster buffer that
we want to use to track the dirty inode through the AIL.
Unfortunately, locking the cluster buffer and adding it to the
transaction when the inode is first logged in a transaction leads to
buffer lock ordering inversions.

The specific problem is ordering against the AGI buffer. When
modifying unlinked lists, the buffer lock order is AGI -> inode
cluster buffer as the AGI buffer lock serialises all access to the
unlinked lists. Unfortunately, functionality like xfs_droplink()
logs the inode before calling xfs_iunlink(), as do various directory
manipulation functions. The inode can be logged way down in the
stack as far as the bmapi routines and hence, without a major
rewrite of lots of APIs there's no way we can avoid the inode being
logged by something until after the AGI has been logged.

As we are going to be using ordered buffers for inode AIL tracking,
there isn't a need to actually lock that buffer against modification
as all the modifications are captured by logging the inode item
itself. Hence we don't actually need to join the cluster buffer into
the transaction until just before it is committed. This means we do
not perturb any of the existing buffer lock orders in transactions,
and the inode cluster buffer is always locked last in a transaction
that doesn't otherwise touch inode cluster buffers.

We do this by introducing a precommit log item method.  This commit
just introduces the mechanism; the inode item implementation is in
followup commits.

The precommit items need to be sorted into consistent order as we
may be locking multiple items here. Hence if we have two dirty
inodes in cluster buffers A and B, and some other transaction has
two separate dirty inodes in the same cluster buffers, locking them
in different orders opens us up to ABBA deadlocks. Hence we sort the
items on the transaction based on the presence of a sort log item
method.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:47:26 +10:00
Dave Chinner
2fd26cc07e xfs: double link the unlinked inode list
Now we have forwards traversal via the incore inode in place, we now
need to add back pointers to the incore inode to entirely replace
the back reference cache. We use the same lookup semantics and
constraints as for the forwards pointer lookups during unlinks, and
so we can look up any inode in the unlinked list directly and update
the list pointers, forwards or backwards, at any time.

The only wrinkle in converting the unlinked list manipulations to
use in-core previous pointers is that log recovery doesn't have the
incore inode state built up so it can't just read in an inode and
release it to finish off the unlink. Hence we need to modify the
traversal in recovery to read one inode ahead before we
release the inode at the head of the list. This populates the
next->prev relationship sufficient to be able to replay the unlinked
list and hence greatly simplify the runtime code.

This recovery algorithm also requires that we actually remove inodes
from the unlinked list one at a time as background inode
inactivation will result in unlinked list removal racing with the
building of the in-memory unlinked list state. We could serialise
this by holding the AGI buffer lock when constructing the in memory
state, but all that does is lockstep background processing with list
building. It is much simpler to flush the inodegc immediately after
releasing the inode so that it is unlinked immediately and there is
no races present at all.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:46:43 +10:00
Darrick J. Wong
e45d7cb235 xfs: use XFS_IFORK_Q to determine the presence of an xattr fork
Modify xfs_ifork_ptr to return a NULL pointer if the caller asks for the
attribute fork but i_forkoff is zero.  This eliminates the ambiguity
between i_forkoff and i_af.if_present, which should make it easier to
understand the lifetime of attr forks.

While we're at it, remove the if_present checks around calls to
xfs_idestroy_fork and xfs_ifork_zap_attr since they can both handle attr
forks that have already been torn down.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-07-09 15:17:21 -07:00
Darrick J. Wong
2ed5b09b3e xfs: make inode attribute forks a permanent part of struct xfs_inode
Syzkaller reported a UAF bug a while back:

==================================================================
BUG: KASAN: use-after-free in xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
Read of size 4 at addr ffff88802cec919c by task syz-executor262/2958

CPU: 2 PID: 2958 Comm: syz-executor262 Not tainted
5.15.0-0.30.3-20220406_1406 #3
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x82/0xa9 lib/dump_stack.c:106
 print_address_description.constprop.9+0x21/0x2d5 mm/kasan/report.c:256
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold.14+0x7f/0x11b mm/kasan/report.c:459
 xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
 xfs_attr_get+0x378/0x4c2 fs/xfs/libxfs/xfs_attr.c:159
 xfs_xattr_get+0xe3/0x150 fs/xfs/xfs_xattr.c:36
 __vfs_getxattr+0xdf/0x13d fs/xattr.c:399
 cap_inode_need_killpriv+0x41/0x5d security/commoncap.c:300
 security_inode_need_killpriv+0x4c/0x97 security/security.c:1408
 dentry_needs_remove_privs.part.28+0x21/0x63 fs/inode.c:1912
 dentry_needs_remove_privs+0x80/0x9e fs/inode.c:1908
 do_truncate+0xc3/0x1e0 fs/open.c:56
 handle_truncate fs/namei.c:3084 [inline]
 do_open fs/namei.c:3432 [inline]
 path_openat+0x30ab/0x396d fs/namei.c:3561
 do_filp_open+0x1c4/0x290 fs/namei.c:3588
 do_sys_openat2+0x60d/0x98c fs/open.c:1212
 do_sys_open+0xcf/0x13c fs/open.c:1228
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0x0
RIP: 0033:0x7f7ef4bb753d
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48
89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73
01 c3 48 8b 0d 1b 79 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007f7ef52c2ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000404148 RCX: 00007f7ef4bb753d
RDX: 00007f7ef4bb753d RSI: 0000000000000000 RDI: 0000000020004fc0
RBP: 0000000000404140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffd794db37f R14: 00007ffd794db470 R15: 00007f7ef52c2fc0
 </TASK>

Allocated by task 2953:
 kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x68/0x7c mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:3213 [inline]
 slab_alloc mm/slub.c:3221 [inline]
 kmem_cache_alloc+0x11b/0x3eb mm/slub.c:3226
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfs_ifork_alloc+0x25/0xa2 fs/xfs/libxfs/xfs_inode_fork.c:287
 xfs_bmap_add_attrfork+0x3f2/0x9b1 fs/xfs/libxfs/xfs_bmap.c:1098
 xfs_attr_set+0xe38/0x12a7 fs/xfs/libxfs/xfs_attr.c:746
 xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
 __vfs_setxattr+0x11b/0x177 fs/xattr.c:180
 __vfs_setxattr_noperm+0x128/0x5e0 fs/xattr.c:214
 __vfs_setxattr_locked+0x1d4/0x258 fs/xattr.c:275
 vfs_setxattr+0x154/0x33d fs/xattr.c:301
 setxattr+0x216/0x29f fs/xattr.c:575
 __do_sys_fsetxattr fs/xattr.c:632 [inline]
 __se_sys_fsetxattr fs/xattr.c:621 [inline]
 __x64_sys_fsetxattr+0x243/0x2fe fs/xattr.c:621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0x0

Freed by task 2949:
 kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x21 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xe2/0x10e mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1700 [inline]
 slab_free_freelist_hook mm/slub.c:1726 [inline]
 slab_free mm/slub.c:3492 [inline]
 kmem_cache_free+0xdc/0x3ce mm/slub.c:3508
 xfs_attr_fork_remove+0x8d/0x132 fs/xfs/libxfs/xfs_attr_leaf.c:773
 xfs_attr_sf_removename+0x5dd/0x6cb fs/xfs/libxfs/xfs_attr_leaf.c:822
 xfs_attr_remove_iter+0x68c/0x805 fs/xfs/libxfs/xfs_attr.c:1413
 xfs_attr_remove_args+0xb1/0x10d fs/xfs/libxfs/xfs_attr.c:684
 xfs_attr_set+0xf1e/0x12a7 fs/xfs/libxfs/xfs_attr.c:802
 xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
 __vfs_removexattr+0x106/0x16a fs/xattr.c:468
 cap_inode_killpriv+0x24/0x47 security/commoncap.c:324
 security_inode_killpriv+0x54/0xa1 security/security.c:1414
 setattr_prepare+0x1a6/0x897 fs/attr.c:146
 xfs_vn_change_ok+0x111/0x15e fs/xfs/xfs_iops.c:682
 xfs_vn_setattr_size+0x5f/0x15a fs/xfs/xfs_iops.c:1065
 xfs_vn_setattr+0x125/0x2ad fs/xfs/xfs_iops.c:1093
 notify_change+0xae5/0x10a1 fs/attr.c:410
 do_truncate+0x134/0x1e0 fs/open.c:64
 handle_truncate fs/namei.c:3084 [inline]
 do_open fs/namei.c:3432 [inline]
 path_openat+0x30ab/0x396d fs/namei.c:3561
 do_filp_open+0x1c4/0x290 fs/namei.c:3588
 do_sys_openat2+0x60d/0x98c fs/open.c:1212
 do_sys_open+0xcf/0x13c fs/open.c:1228
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0x0

The buggy address belongs to the object at ffff88802cec9188
 which belongs to the cache xfs_ifork of size 40
The buggy address is located 20 bytes inside of
 40-byte region [ffff88802cec9188, ffff88802cec91b0)
The buggy address belongs to the page:
page:00000000c3af36a1 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x2cec9
flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000200 ffffea00009d2580 0000000600000006 ffff88801a9ffc80
raw: 0000000000000000 0000000080490049 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88802cec9080: fb fb fb fc fc fa fb fb fb fb fc fc fb fb fb fb
 ffff88802cec9100: fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc
>ffff88802cec9180: fc fa fb fb fb fb fc fc fa fb fb fb fb fc fc fb
                            ^
 ffff88802cec9200: fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb
 ffff88802cec9280: fb fb fc fc fa fb fb fb fb fc fc fa fb fb fb fb
==================================================================

The root cause of this bug is the unlocked access to xfs_inode.i_afp
from the getxattr code paths while trying to determine which ILOCK mode
to use to stabilize the xattr data.  Unfortunately, the VFS does not
acquire i_rwsem when vfs_getxattr (or listxattr) call into the
filesystem, which means that getxattr can race with a removexattr that's
tearing down the attr fork and crash:

xfs_attr_set:                          xfs_attr_get:
xfs_attr_fork_remove:                  xfs_ilock_attr_map_shared:

xfs_idestroy_fork(ip->i_afp);
kmem_cache_free(xfs_ifork_cache, ip->i_afp);

                                       if (ip->i_afp &&

ip->i_afp = NULL;

                                           xfs_need_iread_extents(ip->i_afp))
                                       <KABOOM>

ip->i_forkoff = 0;

Regrettably, the VFS is much more lax about i_rwsem and getxattr than
is immediately obvious -- not only does it not guarantee that we hold
i_rwsem, it actually doesn't guarantee that we *don't* hold it either.
The getxattr system call won't acquire the lock before calling XFS, but
the file capabilities code calls getxattr with and without i_rwsem held
to determine if the "security.capabilities" xattr is set on the file.

Fixing the VFS locking requires a treewide investigation into every code
path that could touch an xattr and what i_rwsem state it expects or sets
up.  That could take years or even prove impossible; fortunately, we
can fix this UAF problem inside XFS.

An earlier version of this patch used smp_wmb in xfs_attr_fork_remove to
ensure that i_forkoff is always zeroed before i_afp is set to null and
changed the read paths to use smp_rmb before accessing i_forkoff and
i_afp, which avoided these UAF problems.  However, the patch author was
too busy dealing with other problems in the meantime, and by the time he
came back to this issue, the situation had changed a bit.

On a modern system with selinux, each inode will always have at least
one xattr for the selinux label, so it doesn't make much sense to keep
incurring the extra pointer dereference.  Furthermore, Allison's
upcoming parent pointer patchset will also cause nearly every inode in
the filesystem to have extended attributes.  Therefore, make the inode
attribute fork structure part of struct xfs_inode, at a cost of 40 more
bytes.

This patch adds a clunky if_present field where necessary to maintain
the existing logic of xattr fork null pointer testing in the existing
codebase.  The next patch switches the logic over to XFS_IFORK_Q and it
all goes away.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-07-09 15:17:21 -07:00
Darrick J. Wong
732436ef91 xfs: convert XFS_IFORK_PTR to a static inline helper
We're about to make this logic do a bit more, so convert the macro to a
static inline function for better typechecking and fewer shouty macros.
No functional changes here.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-07-09 15:17:21 -07:00
Roman Gushchin
e33c267ab7 mm: shrinkers: provide shrinkers with names
Currently shrinkers are anonymous objects.  For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g.  for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

This commit adds names to shrinkers.  register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.

In some cases it's not possible to determine a good name at the time when
a shrinker is allocated.  For such cases shrinker_debugfs_rename() is
provided.

The expected format is:
    <subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.

After this change the shrinker debugfs directory looks like:
  $ cd /sys/kernel/debug/shrinker/
  $ ls
    dquota-cache-16     sb-devpts-28     sb-proc-47       sb-tmpfs-42
    mm-shadow-18        sb-devtmpfs-5    sb-proc-48       sb-tmpfs-43
    mm-zspool:zram0-34  sb-hugetlbfs-17  sb-pstore-31     sb-tmpfs-44
    rcu-kfree-0         sb-hugetlbfs-33  sb-rootfs-2      sb-tmpfs-49
    sb-aio-20           sb-iomem-12      sb-securityfs-6  sb-tracefs-13
    sb-anon_inodefs-15  sb-mqueue-21     sb-selinuxfs-22  sb-xfs:vda1-36
    sb-bdev-3           sb-nsfs-4        sb-sockfs-8      sb-zsmalloc-19
    sb-bpf-32           sb-pipefs-14     sb-sysfs-26      thp-deferred_split-10
    sb-btrfs:vda2-24    sb-proc-25       sb-tmpfs-1       thp-zero-9
    sb-cgroup2-30       sb-proc-39       sb-tmpfs-27      xfs-buf:vda1-37
    sb-configfs-23      sb-proc-41       sb-tmpfs-29      xfs-inodegc:vda1-38
    sb-dax-11           sb-proc-45       sb-tmpfs-35
    sb-debugfs-7        sb-proc-46       sb-tmpfs-40

[roman.gushchin@linux.dev: fix build warnings]
  Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
  Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:40 -07:00
Dave Chinner
5e672cd69f xfs: introduce xfs_inodegc_push()
The current blocking mechanism for pushing the inodegc queue out to
disk can result in systems becoming unusable when there is a long
running inodegc operation. This is because the statfs()
implementation currently issues a blocking flush of the inodegc
queue and a significant number of common system utilities will call
statfs() to discover something about the underlying filesystem.

This can result in userspace operations getting stuck on inodegc
progress, and when trying to remove a heavily reflinked file on slow
storage with a full journal, this can result in delays measuring in
hours.

Avoid this problem by adding "push" function that expedites the
flushing of the inodegc queue, but doesn't wait for it to complete.

Convert xfs_fs_statfs() and xfs_qm_scall_getquota() to use this
mechanism so they don't block but still ensure that queued
operations are expedited.

Fixes: ab23a77687 ("xfs: per-cpu deferred inode inactivation queues")
Reported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[djwong: fix _getquota_next to use _inodegc_push too]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-06-23 13:34:38 -07:00
Dave Chinner
7cf2b0f961 xfs: bound maximum wait time for inodegc work
Currently inodegc work can sit queued on the per-cpu queue until
the workqueue is either flushed of the queue reaches a depth that
triggers work queuing (and later throttling). This means that we
could queue work that waits for a long time for some other event to
trigger flushing.

Hence instead of just queueing work at a specific depth, use a
delayed work that queues the work at a bound time. We can still
schedule the work immediately at a given depth, but we no long need
to worry about leaving a number of items on the list that won't get
processed until external events prevail.

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>
2022-06-23 13:34:38 -07:00
Darrick J. Wong
2229276c52 xfs: use a separate frextents counter for rt extent reservations
As mentioned in the previous commit, the kernel misuses sb_frextents in
the incore mount to reflect both incore reservations made by running
transactions as well as the actual count of free rt extents on disk.
This results in the superblock being written to the log with an
underestimate of the number of rt extents that are marked free in the
rtbitmap.

Teaching XFS to recompute frextents after log recovery avoids
operational problems in the current mount, but it doesn't solve the
problem of us writing undercounted frextents which are then recovered by
an older kernel that doesn't have that fix.

Create an incore percpu counter to mirror the ondisk frextents.  This
new counter will track transaction reservations and the only time we
will touch the incore super counter (i.e the one that gets logged) is
when those transactions commit updates to the rt bitmap.  This is in
contrast to the lazysbcount counters (e.g. fdblocks), where we know that
log recovery will always fix any incorrect counter that we log.
As a bonus, we only take m_sb_lock at transaction commit time.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-12 06:49:42 +10:00
Linus Torvalds
b32e3819a8 Bug fixes for 5.18:
- Fix an incorrect free space calculation in xfs_reserve_blocks that
   could lead to a request for free blocks that will never succeed.
 - Fix a hang in xfs_reserve_blocks caused by an infinite loop and the
   incorrect free space calculation.
 - Fix yet a third problem in xfs_reserve_blocks where multiple racing
   threads can overfill the reserve pool.
 - Fix an accounting error that lead to us reporting reserved space as
   "available".
 - Fix a race condition during abnormal fs shutdown that could cause UAF
   problems when memory reclaim and log shutdown try to clean up inodes.
 - Fix a bug where log shutdown can race with unmount to tear down the
   log, thereby causing UAF errors.
 - Disentangle log and filesystem shutdown to reduce confusion.
 - Fix some confusion in xfs_trans_commit such that a race between
   transaction commit and filesystem shutdown can cause unlogged dirty
   inode metadata to be committed, thereby corrupting the filesystem.
 - Remove a performance optimization in the log as it was discovered that
   certain storage hardware handle async log flushes so poorly as to
   cause serious performance regressions.  Recent restructuring of other
   parts of the logging code mean that no performance benefit is seen on
   hardware that handle it well.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmJEjg4ACgkQ+H93GTRK
 tOsUHRAAj5n65L1r80HSuayipWrwyuD2paa3cqtV76Y8n6CBck8CcnWjZ1t88NYO
 rvfRWKlkJAxkafc5dOiEQ4lm0AL2pHuAWeMrVu/EHvwzj9D+F/GXPrgWCJ1spsN/
 Osd8LgMrxrOaaHgPhENKGa4Ktc5dQoRfDD1IvbAyPEt2puLjoRm00STqUFMYuejR
 96yzreL8kLQdnErxKlQzo4ShsdckyBqA62AAQBIVr3B93+plefTXrWlp2HrblP11
 Upd/sdrIdVp/n104fAfaMT5pSamn3NGyV+8FaUjruBv/alC7pWrWrah6KuBl9omy
 ql8wvtO5KTQdESLx2wjYpC5odi9hQfJYDLCMN3B6gxXg26mcZVvOCfSNtrayPkYj
 ShfkT4mn+TFPFqG/NOgg8ebPp94fzXctKZ+ExVg1dGVAR9oz8QlUUmsqIdbq/4tx
 hrkGOKTa/oGBVoakHgGfbfY5Zz4yX5hVjGWN+l54YRKWHZwYDatRT/O4GkQEZqlU
 dgXsZFT0IZpz4WuTCan+VPJ85I+SKuoYsjh0n4rlGgfCcVK81uvtRB+Jn9rO0wHW
 Uzv1S6HrzblvBnUZGVt49z3co+APYwIRKY8mb+YHWmVNQqmZqyUj7KyFvxuTTkOm
 g0b8oK0/3hpC70v91aTFQmpA6R6cQAS2D4JsM4nXxjyluRWAphI=
 =6Vg8
 -----END PGP SIGNATURE-----

Merge tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "This fixes multiple problems in the reserve pool sizing functions: an
  incorrect free space calculation, a pointless infinite loop, and even
  more braindamage that could result in the pool being overfilled. The
  pile of patches from Dave fix myriad races and UAF bugs in the log
  recovery code that much to our mutual surprise nobody's tripped over.
  Dave also fixed a performance optimization that had turned into a
  regression.

  Dave Chinner is taking over as XFS maintainer starting Sunday and
  lasting until 5.19-rc1 is tagged so that I can focus on starting a
  massive design review for the (feature complete after five years)
  online repair feature. From then on, he and I will be moving XFS to a
  co-maintainership model by trading duties every other release.

  NOTE: I hope very strongly that the other pieces of the (X)FS
  ecosystem (fstests and xfsprogs) will make similar changes to spread
  their maintenance load.

  Summary:

   - Fix an incorrect free space calculation in xfs_reserve_blocks that
     could lead to a request for free blocks that will never succeed.

   - Fix a hang in xfs_reserve_blocks caused by an infinite loop and the
     incorrect free space calculation.

   - Fix yet a third problem in xfs_reserve_blocks where multiple racing
     threads can overfill the reserve pool.

   - Fix an accounting error that lead to us reporting reserved space as
     "available".

   - Fix a race condition during abnormal fs shutdown that could cause
     UAF problems when memory reclaim and log shutdown try to clean up
     inodes.

   - Fix a bug where log shutdown can race with unmount to tear down the
     log, thereby causing UAF errors.

   - Disentangle log and filesystem shutdown to reduce confusion.

   - Fix some confusion in xfs_trans_commit such that a race between
     transaction commit and filesystem shutdown can cause unlogged dirty
     inode metadata to be committed, thereby corrupting the filesystem.

   - Remove a performance optimization in the log as it was discovered
     that certain storage hardware handle async log flushes so poorly as
     to cause serious performance regressions. Recent restructuring of
     other parts of the logging code mean that no performance benefit is
     seen on hardware that handle it well"

* tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: drop async cache flushes from CIL commits.
  xfs: shutdown during log recovery needs to mark the log shutdown
  xfs: xfs_trans_commit() path must check for log shutdown
  xfs: xfs_do_force_shutdown needs to block racing shutdowns
  xfs: log shutdown triggers should only shut down the log
  xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks
  xfs: shutdown in intent recovery has non-intent items in the AIL
  xfs: aborting inodes on shutdown may need buffer lock
  xfs: don't report reserved bnobt space as available
  xfs: fix overfilling of reserve pool
  xfs: always succeed at setting the reserve pool size
  xfs: remove infinite loop when reserving free block pool
  xfs: don't include bnobt blocks when reserving free block pool
  xfs: document the XFS_ALLOC_AGFL_RESERVE constant
2022-04-01 19:30:44 -07:00
Dave Chinner
d2d7c04735 xfs: aborting inodes on shutdown may need buffer lock
Most buffer io list operations are run with the bp->b_lock held, but
xfs_iflush_abort() can be called without the buffer lock being held
resulting in inodes being removed from the buffer list while other
list operations are occurring. This causes problems with corrupted
bp->b_io_list inode lists during filesystem shutdown, leading to
traversals that never end, double removals from the AIL, etc.

Fix this by passing the buffer to xfs_iflush_abort() if we have
it locked. If the inode is attached to the buffer, we're going to
have to remove it from the buffer list and we'd have to get the
buffer off the inode log item to do that anyway.

If we don't have a buffer passed in (e.g. from xfs_reclaim_inode())
then we can determine if the inode has a log item and if it is
attached to a buffer before we do anything else. If it does have an
attached buffer, we can lock it safely (because the inode has a
reference to it) and then perform the inode abort.

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>
2022-03-29 18:21:59 -07:00
Linus Torvalds
b1b07ba356 New code for 5.18:
- Fix some incorrect mapping state being passed to iomap during COW
  - Don't create bogus selinux audit messages when deciding to degrade
    gracefully due to lack of privilege
  - Fix setattr implementation to use VFS helpers so that we drop setgid
    consistently with the other filesystems
  - Fix link/unlink/rename to check quota limits
  - Constify xfs_name_dotdot to prevent abuse of in-kernel symbols
  - Fix log livelock between the AIL and inodegc threads during recovery
  - Fix a log stall when the AIL races with pushers
  - Fix stalls in CIL flushes due to pinned inode cluster buffers during
    recovery
  - Fix log corruption due to incorrect usage of xfs_is_shutdown vs
    xlog_is_shutdown because during an induced fs shutdown, AIL writeback
    must continue until the log is shut down, even if the filesystem has
    already shut down
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmI3UQ8ACgkQ+H93GTRK
 tOttpBAAjz05QkClIYKlHREiWt4a2a0FnRBvkz2fvZb0Nk3kST/drJ14VAb1Q3g1
 HvvOGwssyJShkbd6DBGTqrp9AzZ0mfhSYPpARtCNwOvUNV4tXwLdiBZ86H4/l3qy
 seS1tXW4pUKm6xhN9fnMw1sk4oJmPXq67JW+1h35oDaE6tpdd9lehFMpMxaTMjED
 4WsU0UwKCWr4l1lKP1EXvh+ENJeo0QZpccNHV3ChLnWx0mPMRpf4tQP2A01oBPkh
 oXHSms0TV7FHDIv+Zil3kBgkfh266WhcPdZ4pfIqyQc51LzbgrxEqcrZHGI5XJjB
 zcQd8RkzOI68XIDchijOorOkQZmDEDIGlCgSY6q/JV4N2iFyF84hHedk2le5j97l
 Jmout2Xng3bgstl4963IjXk8SvPTebnI76a62XoEcHnf4KBROLKIU7wNCh5LXNvk
 CI6AWJGy6EAGEc3BHyPFZxZF72D9rUmRbPIJBc7rBhJgMoIy4L4sFlvVtyppbERb
 gMH9PNTLjY5/abQkV044iLOsEDh5FEPBIehoaENNo252vj2R/WsAAQL13l0cMsrN
 vAryGdAEelZEyg62k+HT4W87zjH0Kgtgli6zMdx7akYdjKbMOIZALEu61iBH7KT+
 heAz8pU/krTy+Q583XU13eCWnY1wPrHRMwdGF+i4WUGiKuJSoYg=
 =uHT0
 -----END PGP SIGNATURE-----

Merge tag 'xfs-5.18-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "The biggest change this cycle is bringing XFS' inode attribute setting
  code back towards alignment with what the VFS does. IOWs, setgid bit
  handling should be a closer match with ext4 and btrfs behavior.

  The rest of the branch is bug fixes around the filesystem -- patching
  gaps in quota enforcement, removing bogus selinux audit messages, and
  fixing log corruption and problems with log recovery. There will be a
  second pull request later on in the merge window with more bug fixes.

  Dave Chinner will be taking over as XFS maintainer for one release
  cycle, starting from the day 5.18-rc1 drops until 5.19-rc1 is tagged
  so that I can focus on starting a massive design review for the
  (feature complete after five years) online repair feature.

  Summary:

   - Fix some incorrect mapping state being passed to iomap during COW

   - Don't create bogus selinux audit messages when deciding to degrade
     gracefully due to lack of privilege

   - Fix setattr implementation to use VFS helpers so that we drop
     setgid consistently with the other filesystems

   - Fix link/unlink/rename to check quota limits

   - Constify xfs_name_dotdot to prevent abuse of in-kernel symbols

   - Fix log livelock between the AIL and inodegc threads during
     recovery

   - Fix a log stall when the AIL races with pushers

   - Fix stalls in CIL flushes due to pinned inode cluster buffers
     during recovery

   - Fix log corruption due to incorrect usage of xfs_is_shutdown vs
     xlog_is_shutdown because during an induced fs shutdown, AIL
     writeback must continue until the log is shut down, even if the
     filesystem has already shut down"

* tag 'xfs-5.18-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: xfs_is_shutdown vs xlog_is_shutdown cage fight
  xfs: AIL should be log centric
  xfs: log items should have a xlog pointer, not a mount
  xfs: async CIL flushes need pending pushes to be made stable
  xfs: xfs_ail_push_all_sync() stalls when racing with updates
  xfs: check buffer pin state after locking in delwri_submit
  xfs: log worker needs to start before intent/unlink recovery
  xfs: constify xfs_name_dotdot
  xfs: constify the name argument to various directory functions
  xfs: reserve quota for target dir expansion when renaming files
  xfs: reserve quota for dir expansion when linking/unlinking files
  xfs: refactor user/group quota chown in xfs_setattr_nonsize
  xfs: use setattr_copy to set vfs inode attributes
  xfs: don't generate selinux audit messages for capability testing
  xfs: add missing cmap->br_state = XFS_EXT_NORM update
2022-03-24 18:28:01 -07:00
Muchun Song
fd60b28842 fs: allocate inode by using alloc_inode_sb()
The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().

Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>		[ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:03 -07:00
Dave Chinner
01728b44ef xfs: xfs_is_shutdown vs xlog_is_shutdown cage fight
I've been chasing a recent resurgence in generic/388 recovery
failure and/or corruption events. The events have largely been
uninitialised inode chunks being tripped over in log recovery
such as:

 XFS (pmem1): User initiated shutdown received.
 pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
 XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/xfs/xfs_fsops.c:500).  Shutting down filesystem.
 XFS (pmem1): Please unmount the filesystem and rectify the problem(s)
 XFS (pmem1): Unmounting Filesystem
 XFS (pmem1): Mounting V5 Filesystem
 XFS (pmem1): Starting recovery (logdev: internal)
 XFS (pmem1): bad inode magic/vsn daddr 8723584 #0 (magic=1818)
 XFS (pmem1): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x851c80 xfs_inode_buf_verify
 XFS (pmem1): Unmount and run xfs_repair
 XFS (pmem1): First 128 bytes of corrupted metadata buffer:
 00000000: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000010: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000020: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000030: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000040: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000050: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000060: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000070: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 XFS (pmem1): metadata I/O error in "xlog_recover_items_pass2+0x52/0xc0" at daddr 0x851c80 len 32 error 117
 XFS (pmem1): log mount/recovery failed: error -117
 XFS (pmem1): log mount failed

There have been isolated random other issues, too - xfs_repair fails
because it finds some corruption in symlink blocks, rmap
inconsistencies, etc - but they are nowhere near as common as the
uninitialised inode chunk failure.

The problem has clearly happened at runtime before recovery has run;
I can see the ICREATE log item in the log shortly before the
actively recovered range of the log. This means the ICREATE was
definitely created and written to the log, but for some reason the
tail of the log has been moved past the ordered buffer log item that
tracks INODE_ALLOC buffers and, supposedly, prevents the tail of the
log moving past the ICREATE log item before the inode chunk buffer
is written to disk.

Tracing the fsstress processes that are running when the filesystem
shut down immediately pin-pointed the problem:

user shutdown marks xfs_mount as shutdown

         godown-213341 [008]  6398.022871: console:              [ 6397.915392] XFS (pmem1): User initiated shutdown received.
.....

aild tries to push ordered inode cluster buffer

  xfsaild/pmem1-213314 [001]  6398.022974: xfs_buf_trylock:      dev 259:1 daddr 0x851c80 bbcount 0x20 hold 16 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_inode_item_push+0x8e
  xfsaild/pmem1-213314 [001]  6398.022976: xfs_ilock_nowait:     dev 259:1 ino 0x851c80 flags ILOCK_SHARED caller xfs_iflush_cluster+0xae

xfs_iflush_cluster() checks xfs_is_shutdown(), returns true,
calls xfs_iflush_abort() to kill writeback of the inode.
Inode is removed from AIL, drops cluster buffer reference.

  xfsaild/pmem1-213314 [001]  6398.022977: xfs_ail_delete:       dev 259:1 lip 0xffff88880247ed80 old lsn 7/20344 new lsn 7/21000 type XFS_LI_INODE flags IN_AIL
  xfsaild/pmem1-213314 [001]  6398.022978: xfs_buf_rele:         dev 259:1 daddr 0x851c80 bbcount 0x20 hold 17 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_iflush_abort+0xd7

.....

All inodes on cluster buffer are aborted, then the cluster buffer
itself is aborted and removed from the AIL *without writeback*:

xfsaild/pmem1-213314 [001]  6398.023011: xfs_buf_error_relse:  dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_ioend_fail+0x33
   xfsaild/pmem1-213314 [001]  6398.023012: xfs_ail_delete:       dev 259:1 lip 0xffff8888053efde8 old lsn 7/20344 new lsn 7/20344 type XFS_LI_BUF flags IN_AIL

The inode buffer was at 7/20344 when it was removed from the AIL.

   xfsaild/pmem1-213314 [001]  6398.023012: xfs_buf_item_relse:   dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_done+0x31
   xfsaild/pmem1-213314 [001]  6398.023012: xfs_buf_rele:         dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_relse+0x39

.....

Userspace is still running, doing stuff. an fsstress process runs
syncfs() or sync() and we end up in sync_fs_one_sb() which issues
a log force. This pushes on the CIL:

        fsstress-213322 [001]  6398.024430: xfs_fs_sync_fs:       dev 259:1 m_features 0x20000000019ff6e9 opstate (clean|shutdown|inodegc|blockgc) s_flags 0x70810000 caller sync_fs_one_sb+0x26
        fsstress-213322 [001]  6398.024430: xfs_log_force:        dev 259:1 lsn 0x0 caller xfs_fs_sync_fs+0x82
        fsstress-213322 [001]  6398.024430: xfs_log_force:        dev 259:1 lsn 0x5f caller xfs_log_force+0x7c
           <...>-194402 [001]  6398.024467: kmem_alloc:           size 176 flags 0x14 caller xlog_cil_push_work+0x9f

And the CIL fills up iclogs with pending changes. This picks up
the current tail from the AIL:

           <...>-194402 [001]  6398.024497: xlog_iclog_get_space: dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x0 flags  caller xlog_write+0x149
           <...>-194402 [001]  6398.024498: xlog_iclog_switch:    dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x700005408 flags  caller xlog_state_get_iclog_space+0x37e
           <...>-194402 [001]  6398.024521: xlog_iclog_release:   dev 259:1 state XLOG_STATE_WANT_SYNC refcnt 1 offset 32256 lsn 0x700005408 flags  caller xlog_write+0x5f9
           <...>-194402 [001]  6398.024522: xfs_log_assign_tail_lsn: dev 259:1 new tail lsn 7/21000, old lsn 7/20344, last sync 7/21448

And it moves the tail of the log to 7/21000 from 7/20344. This
*moves the tail of the log beyond the ICREATE transaction* that was
at 7/20344 and pinned by the inode cluster buffer that was cancelled
above.

....

         godown-213341 [008]  6398.027005: xfs_force_shutdown:   dev 259:1 tag logerror flags log_io|force_umount file fs/xfs/xfs_fsops.c line_num 500
          godown-213341 [008]  6398.027022: console:              [ 6397.915406] pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
          godown-213341 [008]  6398.030551: console:              [ 6397.919546] XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/

And finally the log itself is now shutdown, stopping all further
writes to the log. But this is too late to prevent the corruption
that moving the tail of the log forwards after we start cancelling
writeback causes.

The fundamental problem here is that we are using the wrong shutdown
checks for log items. We've long conflated mount shutdown with log
shutdown state, and I started separating that recently with the
atomic shutdown state changes in commit b36d4651e1 ("xfs: make
forced shutdown processing atomic"). The changes in that commit
series are directly responsible for being able to diagnose this
issue because it clearly separated mount shutdown from log shutdown.

Essentially, once we start cancelling writeback of log items and
removing them from the AIL because the filesystem is shut down, we
*cannot* update the journal because we may have cancelled the items
that pin the tail of the log. That moves the tail of the log
forwards without having written the metadata back, hence we have
corrupt in memory state and writing to the journal propagates that
to the on-disk state.

What commit b36d4651e1 makes clear is that log item state needs to
change relative to log shutdown, not mount shutdown. IOWs, anything
that aborts metadata writeback needs to check log shutdown state
because log items directly affect log consistency. Having them check
mount shutdown state introduces the above race condition where we
cancel metadata writeback before the log shuts down.

To fix this, this patch works through all log items and converts
shutdown checks to use xlog_is_shutdown() rather than
xfs_is_shutdown(), so that we don't start aborting metadata
writeback before we shut off journal writes.

AFAICT, this race condition is a zero day IO error handling bug in
XFS that dates back to the introduction of XLOG_IO_ERROR,
XLOG_STATE_IOERROR and XFS_FORCED_SHUTDOWN back in January 1997.

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>
2022-03-20 08:59:50 -07:00
Linus Torvalds
1cb69c8044 New code for 5.17:
- Minor cleanup of ioctl32 cruft
 - Clean up open coded inodegc workqueue function calls
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmHpnxUACgkQ+H93GTRK
 tOtpig/9GzzlPSpbjGMU3BW+dfqvYMLV9YcB3bkZLXPJIb/D2UPXzOQd2SvM9ScJ
 XwM857EjrmV7XifEezbBvla33N9ToNv8/IVdmctcc2as4c6VzDXmkiyze7wD+2D/
 i9UJEOjEtaTvqioOMQJpfaATI7y/9N45UFfcjkbmc4lTP0xOvd1Owx9+ujrCYZ9e
 UccsC7ovUzHxxuK1uFhRMI0up1f5urdFA0wFKvEGsfhIzBthU6BDtYUjuzhC/vLV
 DxqPlQgkRqQfzB9loFQOiNNSC2kVF+SKPXZS7k/HiQIALDOKtFNnSanXG5oPB5+d
 DnuSCvJ+RfejmEoDtMydQu0KXN5fq9g7FodH3tAMPPNn8N1l+qJuC//+6VHZjvIB
 GhfHyWkpg/mzSAAqU0sqeGSvzG1byawYNUzueIIcEWLP1qg4O3QkXW7VJ+yuGb70
 gsO7CQjnW20CmJqeftNsBaBor114UjUJLBQsXR8uowKHq/L1MhNh7Ir6lTfQdti+
 S099EVjrrFV0ZVRou1ZyQ5ZWsdGNtz0p0hEEVEPG2ERHOKfbVWLwbL38s8JY7C56
 hBVwQRwZScdIb/SYTWxPXbBJNR/BXUyxrCikk66isQT0kwFCHXE67YaXbFklxybs
 uzKzVYEBPtYhvDeFTa53GEotGw/LDtZD07E58yowlJUqmJtMLM0=
 =EIqW
 -----END PGP SIGNATURE-----

Merge tag 'xfs-5.17-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "One of the patches removes some dead code from xfs_ioctl32.h and the
  other fixes broken workqueue flushing in the inode garbage collector.

   - Minor cleanup of ioctl32 cruft

   - Clean up open coded inodegc workqueue function calls"

* tag 'xfs-5.17-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: flush inodegc workqueue tasks before cancel
  xfs: remove unused xfs_ioctl32.h declarations
2022-01-22 11:04:27 +02:00
Brian Foster
6191cf3ad5 xfs: flush inodegc workqueue tasks before cancel
The xfs_inodegc_stop() helper performs a high level flush of pending
work on the percpu queues and then runs a cancel_work_sync() on each
of the percpu work tasks to ensure all work has completed before
returning.  While cancel_work_sync() waits for wq tasks to complete,
it does not guarantee work tasks have started. This means that the
_stop() helper can queue and instantly cancel a wq task without
having completed the associated work. This can be observed by
tracepoint inspection of a simple "rm -f <file>; fsfreeze -f <mnt>"
test:

	xfs_destroy_inode: ... ino 0x83 ...
	xfs_inode_set_need_inactive: ... ino 0x83 ...
	xfs_inodegc_stop: ...
	...
	xfs_inodegc_start: ...
	xfs_inodegc_worker: ...
	xfs_inode_inactivating: ... ino 0x83 ...

The first few lines show that the inode is removed and need inactive
state set, but the inactivation work has not completed before the
inodegc mechanism stops. The inactivation doesn't actually occur
until the fs is unfrozen and the gc mechanism starts back up. Note
that this test requires fsfreeze to reproduce because xfs_freeze
indirectly invokes xfs_fs_statfs(), which calls xfs_inodegc_flush().

When this occurs, the workqueue try_to_grab_pending() logic first
tries to steal the pending bit, which does not succeed because the
bit has been set by queue_work_on(). Subsequently, it checks for
association of a pool workqueue from the work item under the pool
lock. This association is set at the point a work item is queued and
cleared when dequeued for processing. If the association exists, the
work item is removed from the queue and cancel_work_sync() returns
true. If the pwq association is cleared, the remove attempt assumes
the task is busy and retries (eventually returning false to the
caller after waiting for the work task to complete).

To avoid this race, we can flush each work item explicitly before
cancel. However, since the _queue_all() already schedules each
underlying work item, the workqueue level helpers are sufficient to
achieve the same ordering effect. E.g., the inodegc enabled flag
prevents scheduling any further work in the _stop() case. Use the
drain_workqueue() helper in this particular case to make the intent
a bit more self explanatory.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-01-19 14:58:26 -08:00
Linus Torvalds
f079ab01b5 Convert xfs/iomap to use folios
This should be all that is needed for XFS to use large folios.
 There is no code in this pull request to create large folios, but
 no additional changes should be needed to XFS or iomap once they
 are created.
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmHcpaUACgkQDpNsjXcp
 gj4MUAf+ItcKfgFo1QCMT+6Y0mohVqPme/vdyOCNv6yOOfZZqN5ZQc+2hmxXrRz9
 XPOPwZKL0TttlHSYEJmrm8mqwN8UXl0kqMu4kQqOXMziiD9qpVlaLXOZ7iLdkQxu
 z/xe1iACcGfJUaQCsaMP6BZqp6iETA4qP72dBE4jc6PC4H3OI0pN/900gEbAcLxD
 Yn0a5NhrdS/EySU2aHLB6OcwhqnSiHBVjUbFiuXxuvOYyzLaERIh00Kx3jLdj4DR
 82K4TF8h2IZpALfIDSt0JG+gHLCc+EfF7Yd/xkeEv0md3ncyi+jWvFCFPNJbyFjm
 cYoDTSunfbxwszA2n01R4JM8/KkGwA==
 =IeFX
 -----END PGP SIGNATURE-----

Merge tag 'iomap-5.17' of git://git.infradead.org/users/willy/linux

Pull iomap updates from Matthew Wilcox:
 "Convert xfs/iomap to use folios.

  This should be all that is needed for XFS to use large folios. There
  is no code in this pull request to create large folios, but no
  additional changes should be needed to XFS or iomap once they are
  created.

  Usually this would have come from Darrick, and we had intended that it
  would come that route. Between the holidays and various things which
  Darrick needed to work on, he asked if I could send things directly.

  There weren't any other iomap patches pending for this release, which
  probably also played a role"

* tag 'iomap-5.17' of git://git.infradead.org/users/willy/linux: (26 commits)
  iomap: Inline __iomap_zero_iter into its caller
  xfs: Support large folios
  iomap: Support large folios in invalidatepage
  iomap: Convert iomap_migrate_page() to use folios
  iomap: Convert iomap_add_to_ioend() to take a folio
  iomap: Simplify iomap_do_writepage()
  iomap: Simplify iomap_writepage_map()
  iomap,xfs: Convert ->discard_page to ->discard_folio
  iomap: Convert iomap_write_end_inline to take a folio
  iomap: Convert iomap_write_begin() and iomap_write_end() to folios
  iomap: Convert __iomap_zero_iter to use a folio
  iomap: Allow iomap_write_begin() to be called with the full length
  iomap: Convert iomap_page_mkwrite to use a folio
  iomap: Convert readahead and readpage to use a folio
  iomap: Convert iomap_read_inline_data to take a folio
  iomap: Use folio offsets instead of page offsets
  iomap: Convert bio completions to use folios
  iomap: Pass the iomap_page into iomap_set_range_uptodate
  iomap: Add iomap_invalidate_folio
  iomap: Convert iomap_releasepage to use a folio
  ...
2022-01-12 12:51:41 -08:00
Yang Xu
132c460e49 xfs: Fix comments mentioning xfs_ialloc
Since kernel commit 1abcf26101 ("xfs: move on-disk inode allocation out of xfs_ialloc()"),
xfs_ialloc has been renamed to xfs_init_new_inode. So update this in comments.

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-12-21 09:49:41 -08:00
Matthew Wilcox (Oracle)
6795801366 xfs: Support large folios
Now that iomap has been converted, XFS is large folio safe.
Indicate to the VFS that it can now create large folios for XFS.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-12-18 00:06:08 -05:00
Christoph Hellwig
1090427bf1 xfs: remove xfs_inew_wait
With the remove of xfs_dqrele_all_inodes, xfs_inew_wait and all the
infrastructure used to wake the XFS_INEW bit waitqueue is unused.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 777eb1fa85 ("xfs: remove xfs_dqrele_all_inodes")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-11-24 10:06:02 -08:00
Darrick J. Wong
182696fb02 xfs: rename _zone variables to _cache
Now that we've gotten rid of the kmem_zone_t typedef, rename the
variables to _cache since that's what they are.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:04:20 -07:00
Dave Chinner
f38a032b16 xfs: fix I_DONTCACHE
Yup, the VFS hoist broke it, and nobody noticed. Bulkstat workloads
make it clear that it doesn't work as it should.

Fixes: dae2f8ed79 ("fs: Lift XFS_IDONTCACHE to the VFS layer")
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>
2021-08-24 19:13:04 -07:00
Dave Chinner
75c8c50fa1 xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown
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>
2021-08-19 10:07:13 -07:00
Dave Chinner
2e973b2cd4 xfs: convert remaining mount flags to state flags
The remaining mount flags kept in m_flags are actually runtime state
flags. These change dynamically, so they really should be updated
atomically so we don't potentially lose an update due to racing
modifications.

Convert these remaining flags to be stored in m_opstate and use
atomic bitops to set and clear the flags. This also adds a couple of
simple wrappers for common state checks - read only and shutdown.

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>
2021-08-19 10:07:13 -07:00
Dave Chinner
0560f31a09 xfs: convert mount flags to features
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>
2021-08-19 10:07:12 -07:00
Dave Chinner
38c26bfd90 xfs: replace xfs_sb_version checks with feature flag checks
Convert the xfs_sb_version_hasfoo() to checks against
mp->m_features. Checks of the superblock itself during disk
operations (e.g. in the read/write verifiers and the to/from disk
formatters) are not converted - they operate purely on the
superblock state. Everything else should use the mount features.

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

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

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

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

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

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-19 10:07:12 -07:00
Christoph Hellwig
a437b9b488 xfs: remove support for untagged lookups in xfs_icwalk*
With quotaoff not allowing disabling of accounting there is no need
for untagged lookups in this code, so remove the dead leftovers.

Repoted-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[djwong: convert to for_each_perag_tag]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-18 18:46:02 -07:00
Darrick J. Wong
40b1de007a xfs: throttle inode inactivation queuing on memory reclaim
Now that we defer inode inactivation, we've decoupled the process of
unlinking or closing an inode from the process of inactivating it.  In
theory this should lead to better throughput since we now inactivate the
queued inodes in batches instead of one at a time.

Unfortunately, one of the primary risks with this decoupling is the loss
of rate control feedback between the frontend and background threads.
In other words, a rm -rf /* thread can run the system out of memory if
it can queue inodes for inactivation and jump to a new CPU faster than
the background threads can actually clear the deferred work.  The
workers can get scheduled off the CPU if they have to do IO, etc.

To solve this problem, we configure a shrinker so that it will activate
the /second/ time the shrinkers are called.  The custom shrinker will
queue all percpu deferred inactivation workers immediately and set a
flag to force frontend callers who are releasing a vfs inode to wait for
the inactivation workers.

On my test VM with 560M of RAM and a 2TB filesystem, this seems to solve
most of the OOMing problem when deleting 10 million inodes.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 11:13:17 -07:00
Darrick J. Wong
e8d04c2abc xfs: use background worker pool when transactions can't get free space
In xfs_trans_alloc, if the block reservation call returns ENOSPC, we
call xfs_blockgc_free_space with a NULL icwalk structure to try to free
space.  Each frontend thread that encounters this situation starts its
own walk of the inode cache to see if it can find anything, which is
wasteful since we don't have any additional selection criteria.  For
this one common case, create a function that reschedules all pending
background work immediately and flushes the workqueue so that the scan
can run in parallel.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 11:13:16 -07:00
Darrick J. Wong
6f6490914d xfs: don't run speculative preallocation gc when fs is frozen
Now that we have the infrastructure to switch background workers on and
off at will, fix the block gc worker code so that we don't actually run
the worker when the filesystem is frozen, same as we do for deferred
inactivation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 10:52:19 -07:00
Darrick J. Wong
2eb665027b xfs: inactivate inodes any time we try to free speculative preallocations
Other parts of XFS have learned to call xfs_blockgc_free_{space,quota}
to try to free speculative preallocations when space is tight.  This
means that file writes, transaction reservation failures, quota limit
enforcement, and the EOFBLOCKS ioctl all call this function to free
space when things are tight.

Since inode inactivation is now a background task, this means that the
filesystem can be hanging on to unlinked but not yet freed space.  Add
this to the list of things that xfs_blockgc_free_* makes writer threads
scan for when they cannot reserve space.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 10:52:18 -07:00
Darrick J. Wong
65f03d8652 xfs: queue inactivation immediately when free realtime extents are tight
Now that we have made the inactivation of unlinked inodes a background
task to increase the throughput of file deletions, we need to be a
little more careful about how long of a delay we can tolerate.

Similar to the patch doing this for free space on the data device, if
the file being inactivated is a realtime file and the realtime volume is
running low on free extents, we want to run the worker ASAP so that the
realtime allocator can make better decisions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 10:52:18 -07:00
Darrick J. Wong
108523b8de xfs: queue inactivation immediately when quota is nearing enforcement
Now that we have made the inactivation of unlinked inodes a background
task to increase the throughput of file deletions, we need to be a
little more careful about how long of a delay we can tolerate.

Specifically, if the dquots attached to the inode being inactivated are
nearing any kind of enforcement boundary, we want to queue that
inactivation work immediately so that users don't get EDQUOT/ENOSPC
errors even after they deleted a bunch of files to stay within quota.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 10:52:18 -07:00
Darrick J. Wong
7d6f07d2c5 xfs: queue inactivation immediately when free space is tight
Now that we have made the inactivation of unlinked inodes a background
task to increase the throughput of file deletions, we need to be a
little more careful about how long of a delay we can tolerate.

On a mostly empty filesystem, the risk of the allocator making poor
decisions due to fragmentation of the free space on account a lengthy
delay in background updates is minimal because there's plenty of space.
However, if free space is tight, we want to deallocate unlinked inodes
as quickly as possible to avoid fallocate ENOSPC and to give the
allocator the best shot at optimal allocations for new writes.

Therefore, queue the percpu worker immediately if the filesystem is more
than 95% full.  This follows the same principle that XFS becomes less
aggressive about speculative allocations and lazy cleanup (and more
precise about accounting) when nearing full.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-09 10:52:17 -07:00
Dave Chinner
ab23a77687 xfs: per-cpu deferred inode inactivation queues
Move inode inactivation to background work contexts so that it no
longer runs in the context that releases the final reference to an
inode. This will allow process work that ends up blocking on
inactivation to continue doing work while the filesytem processes
the inactivation in the background.

A typical demonstration of this is unlinking an inode with lots of
extents. The extents are removed during inactivation, so this blocks
the process that unlinked the inode from the directory structure. By
moving the inactivation to the background process, the userspace
applicaiton can keep working (e.g. unlinking the next inode in the
directory) while the inactivation work on the previous inode is
done by a different CPU.

The implementation of the queue is relatively simple. We use a
per-cpu lockless linked list (llist) to queue inodes for
inactivation without requiring serialisation mechanisms, and a work
item to allow the queue to be processed by a CPU bound worker
thread. We also keep a count of the queue depth so that we can
trigger work after a number of deferred inactivations have been
queued.

The use of a bound workqueue with a single work depth allows the
workqueue to run one work item per CPU. We queue the work item on
the CPU we are currently running on, and so this essentially gives
us affine per-cpu worker threads for the per-cpu queues. THis
maintains the effective CPU affinity that occurs within XFS at the
AG level due to all objects in a directory being local to an AG.
Hence inactivation work tends to run on the same CPU that last
accessed all the objects that inactivation accesses and this
maintains hot CPU caches for unlink workloads.

A depth of 32 inodes was chosen to match the number of inodes in an
inode cluster buffer. This hopefully allows sequential
allocation/unlink behaviours to defering inactivation of all the
inodes in a single cluster buffer at a time, further helping
maintain hot CPU and buffer cache accesses while running
inactivations.

A hard per-cpu queue throttle of 256 inode has been set to avoid
runaway queuing when inodes that take a long to time inactivate are
being processed. For example, when unlinking inodes with large
numbers of extents that can take a lot of processing to free.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
[djwong: tweak comments and tracepoints, convert opflags to state bits]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-06 11:05:39 -07:00
Darrick J. Wong
62af7d54a0 xfs: detach dquots from inode if we don't need to inactivate it
If we don't need to inactivate an inode, we can detach the dquots and
move on to reclamation.  This isn't strictly required here; it's a
preparation patch for deferred inactivation per reviewer request[1] to
move the creation of xfs_inode_needs_inactivation into a separate
change.  Eventually this !need_inactive chunk will turn into the code
path for inodes that skip xfs_inactive and go straight to memory
reclaim.

[1] https://lore.kernel.org/linux-xfs/20210609012838.GW2945738@locust/T/#mca6d958521cb88bbc1bfe1a30767203328d410b5
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-06 11:05:39 -07:00
Darrick J. Wong
c6c2066db3 xfs: move xfs_inactive call to xfs_inode_mark_reclaimable
Move the xfs_inactive call and all the other debugging checks and stats
updates into xfs_inode_mark_reclaimable because most of that are
implementation details about the inode cache.  This is preparation for
deferred inactivation that is coming up.  We also move it around
xfs_icache.c in preparation for deferred inactivation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-08-06 11:05:38 -07:00
Christoph Hellwig
777eb1fa85 xfs: remove xfs_dqrele_all_inodes
xfs_dqrele_all_inodes is unused now, remove it and all supporting code.

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>
2021-08-06 11:05:36 -07:00
Darrick J. Wong
10be350b8c xfs: fix type mismatches in the inode reclaim functions
It's currently unlikely that we will ever end up with more than 4
billion inodes waiting for reclamation, but the fs object code uses long
int for object counts and we're certainly capable of generating that
many.  Instead of truncating the internal counters, widen them and
report the object counts correctly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-06-21 10:12:46 -07:00
Darrick J. Wong
77b4d2861e xfs: separate primary inode selection criteria in xfs_iget_cache_hit
During review of the v6 deferred inode inactivation patchset[1], Dave
commented that _cache_hit should have a clear separation between inode
selection criteria and actions performed on a selected inode.  Move a
hunk to make this true, and compact the shrink cases in the function.

[1] https://lore.kernel.org/linux-xfs/162310469340.3465262.504398465311182657.stgit@locust/T/#mca6d958521cb88bbc1bfe1a30767203328d410b5
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2021-06-21 10:12:46 -07:00
Darrick J. Wong
ff7bebeb91 xfs: refactor the inode recycling code
Hoist the code in xfs_iget_cache_hit that restores the VFS inode state
to an xfs_inode that was previously vfs-destroyed.  The next patch will
add a new set of state flags, so we need the helper to avoid
duplication.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-06-21 10:12:46 -07:00