1
Commit Graph

325 Commits

Author SHA1 Message Date
Linus Torvalds
5ad8b6ad9a getting rid of bogus set_blocksize() uses, switching it
to struct file * and verifying that caller has device
 opened exclusively.
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Merge tag 'pull-set_blocksize' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs blocksize updates from Al Viro:
 "This gets rid of bogus set_blocksize() uses, switches it over
  to be based on a 'struct file *' and verifies that the caller
  has the device opened exclusively"

* tag 'pull-set_blocksize' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make set_blocksize() fail unless block device is opened exclusive
  set_blocksize(): switch to passing struct file *
  btrfs_get_bdev_and_sb(): call set_blocksize() only for exclusive opens
  swsusp: don't bother with setting block size
  zram: don't bother with reopening - just use O_EXCL for open
  swapon(2): open swap with O_EXCL
  swapon(2)/swapoff(2): don't bother with block size
  pktcdvd: sort set_blocksize() calls out
  bcache_register(): don't bother with set_blocksize()
2024-05-21 08:34:51 -07:00
Al Viro
ead083aeee set_blocksize(): switch to passing struct file *
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-02 17:39:44 -04:00
Darrick J. Wong
e47dcf113a xfs: repair extended attributes
If the extended attributes look bad, try to sift through the rubble to
find whatever keys/values we can, stage a new attribute structure in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:53 -07:00
Christian Brauner
22650a9982
fs,block: yield devices early
Currently a device is only really released once the umount returns to
userspace due to how file closing works. That ultimately could cause
an old umount assumption to be violated that concurrent umount and mount
don't fail. So an exclusively held device with a temporary holder should
be yielded before the filesystem is gone. Add a helper that allows
callers to do that. This also allows us to remove the two holder ops
that Linus wasn't excited about.

Link: https://lore.kernel.org/r/20240326-vfs-bdev-end_holder-v1-1-20af85202918@kernel.org
Fixes: f3a608827d ("bdev: open block device as files") # mainline only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-27 13:17:15 +01:00
Linus Torvalds
babbcc0232 New code for 6.9:
* Online Repair;
   ** New ondisk structures being repaired.
      - Inode's mode field by trying to obtain file type value from the a
        directory entry.
      - Quota counters.
      - Link counts of inodes.
      - FS summary counters.
      - rmap btrees.
        Support for in-memory btrees has been added to support repair of rmap
        btrees.
   ** Misc changes
      - Report corruption of metadata to the health tracking subsystem.
      - Enable indirect health reporting when resources are scarce.
      - Reduce memory usage while reparing refcount btree.
      - Extend "Bmap update" intent item to support atomic extent swapping on
        the realtime device.
      - Extend "Bmap update" intent item to support extended attribute fork and
        unwritten extents.
   ** Code cleanups
      - Bmap log intent.
      - Btree block pointer checking.
      - Btree readahead.
      - Buffer target.
      - Symbolic link code.
   * Remove mrlock wrapper around the rwsem.
   * Convert all the GFP_NOFS flag usages to use the scoped
     memalloc_nofs_save() API instead of direct calls with the GFP_NOFS.
   * Refactor and simplify xfile abstraction. Lower level APIs in
     shmem.c are required to be exported in order to achieve this.
   * Skip checking alignment constraints for inode chunk allocations when block
     size is larger than inode chunk size.
   * Do not submit delwri buffers collected during log recovery when an error
     has been encountered.
   * Fix SEEK_HOLE/DATA for file regions which have active COW extents.
   * Fix lock order inversion when executing error handling path during
     shrinking a filesystem.
   * Remove duplicate ifdefs.
 
 Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Chandan Babu:

 - Online repair updates:
    - More ondisk structures being repaired:
        - Inode's mode field by trying to obtain file type value from
          the a directory entry
        - Quota counters
        - Link counts of inodes
        - FS summary counters
        - Support for in-memory btrees has been added to support repair
          of rmap btrees
    - Misc changes:
        - Report corruption of metadata to the health tracking subsystem
        - Enable indirect health reporting when resources are scarce
        - Reduce memory usage while repairing refcount btree
        - Extend "Bmap update" intent item to support atomic extent
          swapping on the realtime device
        - Extend "Bmap update" intent item to support extended attribute
          fork and unwritten extents
    - Code cleanups:
        - Bmap log intent
        - Btree block pointer checking
        - Btree readahead
        - Buffer target
        - Symbolic link code

 - Remove mrlock wrapper around the rwsem

 - Convert all the GFP_NOFS flag usages to use the scoped
   memalloc_nofs_save() API instead of direct calls with the GFP_NOFS

 - Refactor and simplify xfile abstraction. Lower level APIs in shmem.c
   are required to be exported in order to achieve this

 - Skip checking alignment constraints for inode chunk allocations when
   block size is larger than inode chunk size

 - Do not submit delwri buffers collected during log recovery when an
   error has been encountered

 - Fix SEEK_HOLE/DATA for file regions which have active COW extents

 - Fix lock order inversion when executing error handling path during
   shrinking a filesystem

 - Remove duplicate ifdefs

* tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (183 commits)
  xfs: shrink failure needs to hold AGI buffer
  mm/shmem.c: Use new form of *@param in kernel-doc
  kernel-doc: Add unary operator * to $type_param_ref
  xfs: use kvfree() in xlog_cil_free_logvec()
  xfs: xfs_btree_bload_prep_block() should use __GFP_NOFAIL
  xfs: fix scrub stats file permissions
  xfs: fix log recovery erroring out on refcount recovery failure
  xfs: move symlink target write function to libxfs
  xfs: move remote symlink target read function to libxfs
  xfs: move xfs_symlink_remote.c declarations to xfs_symlink_remote.h
  xfs: xfs_bmap_finish_one should map unwritten extents properly
  xfs: support deferred bmap updates on the attr fork
  xfs: support recovering bmap intent items targetting realtime extents
  xfs: add a realtime flag to the bmap update log redo items
  xfs: add a xattr_entry helper
  xfs: fix xfs_bunmapi to allow unmapping of partial rt extents
  xfs: move xfs_bmap_defer_add to xfs_bmap_item.c
  xfs: reuse xfs_bmap_update_cancel_item
  xfs: add a bi_entry helper
  xfs: remove xfs_trans_set_bmap_flags
  ...
2024-03-13 13:52:24 -07:00
Christian Brauner
1b9e2d9014
xfs: port block device access to files
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-7-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-25 12:05:23 +01:00
Darrick J. Wong
5076a6040c xfs: support in-memory buffer cache targets
Allow the buffer cache to target in-memory files by making it possible
to have a buftarg that maps pages from private shmem files.  As the
prevous patch alludes, the in-memory buftarg contains its own cache,
points to a shmem file, and does not point to a block_device.

The next few patches will make it possible to construct an xfs_btree in
pageable memory by using this buftarg.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-02-22 12:43:21 -08:00
Darrick J. Wong
e7b58f7c1b xfs: teach buftargs to maintain their own buffer hashtable
Currently, cached buffers are indexed by per-AG hashtables.  This works
great for the data device, but won't work for in-memory btrees.  To
handle that use case, buftargs will need to be able to index buffers
independently of other data structures.

We accomplish this by hoisting the rhashtable and its lock into a
separate xfs_buf_cache structure, make the buftarg point to the
_buf_cache structure, and rework various functions to use it.  This
will enable the in-memory buftarg to come up with its own _buf_cache.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-02-22 12:42:58 -08:00
Christoph Hellwig
1c51ac0998 xfs: move setting bt_logical_sectorsize out of xfs_setsize_buftarg
bt_logical_sectorsize and the associated mask is set based on the
constant logical block size in the block_device structure and thus
doesn't need to be updated in xfs_setsize_buftarg.  Move it into
xfs_alloc_buftarg so that it is only done once per buftarg.

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>
2024-02-22 12:42:45 -08:00
Christoph Hellwig
60335cc0fb xfs: remove xfs_setsize_buftarg_early
Open code the logic in the only caller, and improve the comment
explaining what is being done here.

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>
2024-02-22 12:42:45 -08:00
Christoph Hellwig
21e308e648 xfs: remove the xfs_buftarg_t typedef
Switch the few remaining holdouts to the struct version.

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>
2024-02-22 12:42:44 -08:00
Christoph Hellwig
24f755e485 xfs: split xfs_buf_rele for cached vs uncached buffers
xfs_buf_rele is a bit confusing because it mixes up handling of normal
cached and the special uncached buffers without much explanation.
Split the handling into two different helpers, and use a clearly named
helper that checks the hash key to distinguish the two cases instead
of checking the pag pointer.

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>
2024-02-22 12:41:02 -08:00
Dave Chinner
204fae32d5 xfs: clean up remaining GFP_NOFS users
These few remaining GFP_NOFS callers do not need to use GFP_NOFS at
all. They are only called from a non-transactional context or cannot
be accessed from memory reclaim due to other constraints. Hence they
can just use GFP_KERNEL.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:35 +05:30
Dave Chinner
0b3a76e955 xfs: use GFP_KERNEL in pure transaction contexts
When running in a transaction context, memory allocations are scoped
to GFP_NOFS. Hence we don't need to use GFP_NOFS contexts in pure
transaction context allocations - GFP_KERNEL will automatically get
converted to GFP_NOFS as appropriate.

Go through the code and convert all the obvious GFP_NOFS allocations
in transaction context to use GFP_KERNEL. This further reduces the
explicit use of GFP_NOFS in XFS.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:35 +05:30
Dave Chinner
d4c75a1b40 xfs: convert remaining kmem_free() to kfree()
The remaining callers of kmem_free() are freeing heap memory, so
we can convert them directly to kfree() and get rid of kmem_free()
altogether.

This conversion was done with:

$ for f in `git grep -l kmem_free fs/xfs`; do
> sed -i s/kmem_free/kfree/ $f
> done
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:34 +05:30
Dave Chinner
f078d4ea82 xfs: convert kmem_alloc() to kmalloc()
kmem_alloc() is just a thin wrapper around kmalloc() these days.
Convert everything to use kmalloc() so we can get rid of the
wrapper.

Note: the transaction region allocation in xlog_add_to_transaction()
can be a high order allocation. Converting it to use
kmalloc(__GFP_NOFAIL) results in warnings in the page allocation
code being triggered because the mm subsystem does not want us to
use __GFP_NOFAIL with high order allocations like we've been doing
with the kmem_alloc() wrapper for a couple of decades. Hence this
specific case gets converted to xlog_kvmalloc() rather than
kmalloc() to avoid this issue.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:34 +05:30
Dave Chinner
10634530f7 xfs: convert kmem_zalloc() to kzalloc()
There's no reason to keep the kmem_zalloc() around anymore, it's
just a thin wrapper around kmalloc(), so lets get rid of it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:33 +05:30
Linus Torvalds
12958e9c4c New code for 6.8:
* New features/functionality
     * Online repair
       * Reserve disk space for online repairs.
       * Fix misinteraction between the AIL and btree bulkloader because of
         which the bulk load fails to queue a buffer for writeback if it
         happens to be on the AIL list.
       * Prevent transaction reservation overflows when reaping blocks during
         online repair.
       * Whenever possible, bulkloader now copies multiple records into a
         block.
       * Support repairing of
         1. Per-AG free space, inode and refcount btrees.
 	2. Ondisk inodes.
 	3. File data and attribute fork mappings.
       * Verify the contents of
         1. Inode and data fork of realtime bitmap file.
 	2. Quota files.
     * Introduce MF_MEM_PRE_REMOVE. This will be used to notify tasks about
       a pmem device being removed.
 
   * Bug fixes
     * Fix memory leak of recovered attri intent items.
     * Fix UAF during log intent recovery.
     * Fix realtime geometry integer overflows.
     * Prevent scrub from live locking in xchk_iget.
     * Prevent fs shutdown when removing files during low free disk space.
     * Prevent transaction reservation overflow when extending an RT device.
     * Prevent incorrect warning from being printed when extending a
       filesystem.
     * Fix an off-by-one error in xreap_agextent_binval.
     * Serialize access to perag radix tree during deletion operation.
     * Fix perag memory leak during growfs.
     * Allow allocation of minlen realtime extent when the maximum sized
       realtime free extent is minlen in size.
 
   * Cleanups
     * Remove duplicate boilerplate code spread across functionality associated
       with different log items.
     * Cleanup resblks interfaces.
     * Pass defer ops pointer to defer helpers instead of an enum.
     * Initialize di_crc in xfs_log_dinode to prevent KMSAN warnings.
     * Use static_assert() instead of BUILD_BUG_ON_MSG() to validate size of
       structures and structure member offsets. This is done in order to be
       able to share the code with userspace.
     * Move XFS documentation under a new directory specific to XFS.
     * Do not invoke deferred ops' ->create_done callback if the deferred
       operation does not have an intent item associated with it.
     * Remove duplicate inclusion of header files from scrub/health.c.
     * Refactor Realtime code.
     * Cleanup attr code.
 
 Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.8-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Chandan Babu:
 "New features/functionality:
   - Online repair:
       - Reserve disk space for online repairs
       - Fix misinteraction between the AIL and btree bulkloader because
         of which the bulk load fails to queue a buffer for writeback if
         it happens to be on the AIL list
       - Prevent transaction reservation overflows when reaping blocks
         during online repair
       - Whenever possible, bulkloader now copies multiple records into
         a block
       - Support repairing of
           1. Per-AG free space, inode and refcount btrees
           2. Ondisk inodes
           3. File data and attribute fork mappings
       - Verify the contents of
           1. Inode and data fork of realtime bitmap file
           2. Quota files
   - Introduce MF_MEM_PRE_REMOVE. This will be used to notify tasks
     about a pmem device being removed

  Bug fixes:
   - Fix memory leak of recovered attri intent items
   - Fix UAF during log intent recovery
   - Fix realtime geometry integer overflows
   - Prevent scrub from live locking in xchk_iget
   - Prevent fs shutdown when removing files during low free disk space
   - Prevent transaction reservation overflow when extending an RT
     device
   - Prevent incorrect warning from being printed when extending a
     filesystem
   - Fix an off-by-one error in xreap_agextent_binval
   - Serialize access to perag radix tree during deletion operation
   - Fix perag memory leak during growfs
   - Allow allocation of minlen realtime extent when the maximum sized
     realtime free extent is minlen in size

  Cleanups:
   - Remove duplicate boilerplate code spread across functionality
     associated with different log items
   - Cleanup resblks interfaces
   - Pass defer ops pointer to defer helpers instead of an enum
   - Initialize di_crc in xfs_log_dinode to prevent KMSAN warnings
   - Use static_assert() instead of BUILD_BUG_ON_MSG() to validate size
     of structures and structure member offsets. This is done in order
     to be able to share the code with userspace
   - Move XFS documentation under a new directory specific to XFS
   - Do not invoke deferred ops' ->create_done callback if the deferred
     operation does not have an intent item associated with it
   - Remove duplicate inclusion of header files from scrub/health.c
   - Refactor Realtime code
   - Cleanup attr code"

* tag 'xfs-6.8-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (123 commits)
  xfs: use the op name in trace_xlog_intent_recovery_failed
  xfs: fix a use after free in xfs_defer_finish_recovery
  xfs: turn the XFS_DA_OP_REPLACE checks in xfs_attr_shortform_addname into asserts
  xfs: remove xfs_attr_sf_hdr_t
  xfs: remove struct xfs_attr_shortform
  xfs: use xfs_attr_sf_findname in xfs_attr_shortform_getvalue
  xfs: remove xfs_attr_shortform_lookup
  xfs: simplify xfs_attr_sf_findname
  xfs: move the xfs_attr_sf_lookup tracepoint
  xfs: return if_data from xfs_idata_realloc
  xfs: make if_data a void pointer
  xfs: fold xfs_rtallocate_extent into xfs_bmap_rtalloc
  xfs: simplify and optimize the RT allocation fallback cascade
  xfs: reorder the minlen and prod calculations in xfs_bmap_rtalloc
  xfs: remove XFS_RTMIN/XFS_RTMAX
  xfs: remove rt-wrappers from xfs_format.h
  xfs: factor out a xfs_rtalloc_sumlevel helper
  xfs: tidy up xfs_rtallocate_extent_exact
  xfs: merge the calls to xfs_rtallocate_range in xfs_rtallocate_block
  xfs: reflow the tail end of xfs_rtallocate_extent_block
  ...
2024-01-10 08:45:22 -08:00
Darrick J. Wong
13ae04d8d4 xfs: force all buffers to be written during btree bulk load
While stress-testing online repair of btrees, I noticed periodic
assertion failures from the buffer cache about buffers with incorrect
DELWRI_Q state.  Looking further, I observed this race between the AIL
trying to write out a btree block and repair zapping a btree block after
the fact:

AIL:    Repair0:

pin buffer X
delwri_queue:
set DELWRI_Q
add to delwri list

        stale buf X:
        clear DELWRI_Q
        does not clear b_list
        free space X
        commit

delwri_submit   # oops

Worse yet, I discovered that running the same repair over and over in a
tight loop can result in a second race that cause data integrity
problems with the repair:

AIL:    Repair0:        Repair1:

pin buffer X
delwri_queue:
set DELWRI_Q
add to delwri list

        stale buf X:
        clear DELWRI_Q
        does not clear b_list
        free space X
        commit

                        find free space X
                        get buffer
                        rewrite buffer
                        delwri_queue:
                        set DELWRI_Q
                        already on a list, do not add
                        commit

                        BAD: committed tree root before all blocks written

delwri_submit   # too late now

I traced this to my own misunderstanding of how the delwri lists work,
particularly with regards to the AIL's buffer list.  If a buffer is
logged and committed, the buffer can end up on that AIL buffer list.  If
btree repairs are run twice in rapid succession, it's possible that the
first repair will invalidate the buffer and free it before the next time
the AIL wakes up.  Marking the buffer stale clears DELWRI_Q from the
buffer state without removing the buffer from its delwri list.  The
buffer doesn't know which list it's on, so it cannot know which lock to
take to protect the list for a removal.

If the second repair allocates the same block, it will then recycle the
buffer to start writing the new btree block.  Meanwhile, if the AIL
wakes up and walks the buffer list, it will ignore the buffer because it
can't lock it, and go back to sleep.

When the second repair calls delwri_queue to put the buffer on the
list of buffers to write before committing the new btree, it will set
DELWRI_Q again, but since the buffer hasn't been removed from the AIL's
buffer list, it won't add it to the bulkload buffer's list.

This is incorrect, because the bulkload caller relies on delwri_submit
to ensure that all the buffers have been sent to disk /before/
committing the new btree root pointer.  This ordering requirement is
required for data consistency.

Worse, the AIL won't clear DELWRI_Q from the buffer when it does finally
drop it, so the next thread to walk through the btree will trip over a
debug assertion on that flag.

To fix this, create a new function that waits for the buffer to be
removed from any other delwri lists before adding the buffer to the
caller's delwri list.  By waiting for the buffer to clear both the
delwri list and any potential delwri wait list, we can be sure that
repair will initiate writes of all buffers and report all write errors
back to userspace instead of committing the new structure.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-15 10:03:27 -08:00
Nhat Pham
0a97c01cd2 list_lru: allow explicit memcg and NUMA node selection
Patch series "workload-specific and memory pressure-driven zswap
writeback", v8.

There are currently several issues with zswap writeback:

1. There is only a single global LRU for zswap, making it impossible to
   perform worload-specific shrinking - an memcg under memory pressure
   cannot determine which pages in the pool it owns, and often ends up
   writing pages from other memcgs. This issue has been previously
   observed in practice and mitigated by simply disabling
   memcg-initiated shrinking:

   https://lore.kernel.org/all/20230530232435.3097106-1-nphamcs@gmail.com/T/#u

   But this solution leaves a lot to be desired, as we still do not
   have an avenue for an memcg to free up its own memory locked up in
   the zswap pool.

2. We only shrink the zswap pool when the user-defined limit is hit.
   This means that if we set the limit too high, cold data that are
   unlikely to be used again will reside in the pool, wasting precious
   memory. It is hard to predict how much zswap space will be needed
   ahead of time, as this depends on the workload (specifically, on
   factors such as memory access patterns and compressibility of the
   memory pages).

This patch series solves these issues by separating the global zswap LRU
into per-memcg and per-NUMA LRUs, and performs workload-specific (i.e
memcg- and NUMA-aware) zswap writeback under memory pressure.  The new
shrinker does not have any parameter that must be tuned by the user, and
can be opted in or out on a per-memcg basis.

As a proof of concept, we ran the following synthetic benchmark: build the
linux kernel in a memory-limited cgroup, and allocate some cold data in
tmpfs to see if the shrinker could write them out and improved the overall
performance.  Depending on the amount of cold data generated, we observe
from 14% to 35% reduction in kernel CPU time used in the kernel builds.


This patch (of 6):

The interface of list_lru is based on the assumption that the list node
and the data it represents belong to the same allocated on the correct
node/memcg.  While this assumption is valid for existing slab objects LRU
such as dentries and inodes, it is undocumented, and rather inflexible for
certain potential list_lru users (such as the upcoming zswap shrinker and
the THP shrinker).  It has caused us a lot of issues during our
development.

This patch changes list_lru interface so that the caller must explicitly
specify numa node and memcg when adding and removing objects.  The old
list_lru_add() and list_lru_del() are renamed to list_lru_add_obj() and
list_lru_del_obj(), respectively.

It also extends the list_lru API with a new function, list_lru_putback,
which undoes a previous list_lru_isolate call.  Unlike list_lru_add, it
does not increment the LRU node count (as list_lru_isolate does not
decrement the node count).  list_lru_putback also allows for explicit
memcg and NUMA node selection.

Link: https://lkml.kernel.org/r/20231130194023.4102148-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20231130194023.4102148-2-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12 10:57:01 -08:00
Linus Torvalds
ecae0bd517 Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
 
 - Kemeng Shi has contributed some compation maintenance work in the
   series "Fixes and cleanups to compaction".
 
 - Joel Fernandes has a patchset ("Optimize mremap during mutual
   alignment within PMD") which fixes an obscure issue with mremap()'s
   pagetable handling during a subsequent exec(), based upon an
   implementation which Linus suggested.
 
 - More DAMON/DAMOS maintenance and feature work from SeongJae Park i the
   following patch series:
 
 	mm/damon: misc fixups for documents, comments and its tracepoint
 	mm/damon: add a tracepoint for damos apply target regions
 	mm/damon: provide pseudo-moving sum based access rate
 	mm/damon: implement DAMOS apply intervals
 	mm/damon/core-test: Fix memory leaks in core-test
 	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval
 
 - In the series "Do not try to access unaccepted memory" Adrian Hunter
   provides some fixups for the recently-added "unaccepted memory' feature.
   To increase the feature's checking coverage.  "Plug a few gaps where
   RAM is exposed without checking if it is unaccepted memory".
 
 - In the series "cleanups for lockless slab shrink" Qi Zheng has done
   some maintenance work which is preparation for the lockless slab
   shrinking code.
 
 - Qi Zheng has redone the earlier (and reverted) attempt to make slab
   shrinking lockless in the series "use refcount+RCU method to implement
   lockless slab shrink".
 
 - David Hildenbrand contributes some maintenance work for the rmap code
   in the series "Anon rmap cleanups".
 
 - Kefeng Wang does more folio conversions and some maintenance work in
   the migration code.  Series "mm: migrate: more folio conversion and
   unification".
 
 - Matthew Wilcox has fixed an issue in the buffer_head code which was
   causing long stalls under some heavy memory/IO loads.  Some cleanups
   were added on the way.  Series "Add and use bdev_getblk()".
 
 - In the series "Use nth_page() in place of direct struct page
   manipulation" Zi Yan has fixed a potential issue with the direct
   manipulation of hugetlb page frames.
 
 - In the series "mm: hugetlb: Skip initialization of gigantic tail
   struct pages if freed by HVO" has improved our handling of gigantic
   pages in the hugetlb vmmemmep optimizaton code.  This provides
   significant boot time improvements when significant amounts of gigantic
   pages are in use.
 
 - Matthew Wilcox has sent the series "Small hugetlb cleanups" - code
   rationalization and folio conversions in the hugetlb code.
 
 - Yin Fengwei has improved mlock()'s handling of large folios in the
   series "support large folio for mlock"
 
 - In the series "Expose swapcache stat for memcg v1" Liu Shixin has
   added statistics for memcg v1 users which are available (and useful)
   under memcg v2.
 
 - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
   prctl so that userspace may direct the kernel to not automatically
   propagate the denial to child processes.  The series is named "MDWE
   without inheritance".
 
 - Kefeng Wang has provided the series "mm: convert numa balancing
   functions to use a folio" which does what it says.
 
 - In the series "mm/ksm: add fork-exec support for prctl" Stefan Roesch
   makes is possible for a process to propagate KSM treatment across
   exec().
 
 - Huang Ying has enhanced memory tiering's calculation of memory
   distances.  This is used to permit the dax/kmem driver to use "high
   bandwidth memory" in addition to Optane Data Center Persistent Memory
   Modules (DCPMM).  The series is named "memory tiering: calculate
   abstract distance based on ACPI HMAT"
 
 - In the series "Smart scanning mode for KSM" Stefan Roesch has
   optimized KSM by teaching it to retain and use some historical
   information from previous scans.
 
 - Yosry Ahmed has fixed some inconsistencies in memcg statistics in the
   series "mm: memcg: fix tracking of pending stats updates values".
 
 - In the series "Implement IOCTL to get and optionally clear info about
   PTEs" Peter Xu has added an ioctl to /proc/<pid>/pagemap which permits
   us to atomically read-then-clear page softdirty state.  This is mainly
   used by CRIU.
 
 - Hugh Dickins contributed the series "shmem,tmpfs: general maintenance"
   - a bunch of relatively minor maintenance tweaks to this code.
 
 - Matthew Wilcox has increased the use of the VMA lock over file-backed
   page faults in the series "Handle more faults under the VMA lock".  Some
   rationalizations of the fault path became possible as a result.
 
 - In the series "mm/rmap: convert page_move_anon_rmap() to
   folio_move_anon_rmap()" David Hildenbrand has implemented some cleanups
   and folio conversions.
 
 - In the series "various improvements to the GUP interface" Lorenzo
   Stoakes has simplified and improved the GUP interface with an eye to
   providing groundwork for future improvements.
 
 - Andrey Konovalov has sent along the series "kasan: assorted fixes and
   improvements" which does those things.
 
 - Some page allocator maintenance work from Kemeng Shi in the series
   "Two minor cleanups to break_down_buddy_pages".
 
 - In thes series "New selftest for mm" Breno Leitao has developed
   another MM self test which tickles a race we had between madvise() and
   page faults.
 
 - In the series "Add folio_end_read" Matthew Wilcox provides cleanups
   and an optimization to the core pagecache code.
 
 - Nhat Pham has added memcg accounting for hugetlb memory in the series
   "hugetlb memcg accounting".
 
 - Cleanups and rationalizations to the pagemap code from Lorenzo
   Stoakes, in the series "Abstract vma_merge() and split_vma()".
 
 - Audra Mitchell has fixed issues in the procfs page_owner code's new
   timestamping feature which was causing some misbehaviours.  In the
   series "Fix page_owner's use of free timestamps".
 
 - Lorenzo Stoakes has fixed the handling of new mappings of sealed files
   in the series "permit write-sealed memfd read-only shared mappings".
 
 - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
   series "Batch hugetlb vmemmap modification operations".
 
 - Some buffer_head folio conversions and cleanups from Matthew Wilcox in
   the series "Finish the create_empty_buffers() transition".
 
 - As a page allocator performance optimization Huang Ying has added
   automatic tuning to the allocator's per-cpu-pages feature, in the series
   "mm: PCP high auto-tuning".
 
 - Roman Gushchin has contributed the patchset "mm: improve performance
   of accounted kernel memory allocations" which improves their performance
   by ~30% as measured by a micro-benchmark.
 
 - folio conversions from Kefeng Wang in the series "mm: convert page
   cpupid functions to folios".
 
 - Some kmemleak fixups in Liu Shixin's series "Some bugfix about
   kmemleak".
 
 - Qi Zheng has improved our handling of memoryless nodes by keeping them
   off the allocation fallback list.  This is done in the series "handle
   memoryless nodes more appropriately".
 
 - khugepaged conversions from Vishal Moola in the series "Some
   khugepaged folio conversions".
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Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Many singleton patches against the MM code. The patch series which are
  included in this merge do the following:

   - Kemeng Shi has contributed some compation maintenance work in the
     series 'Fixes and cleanups to compaction'

   - Joel Fernandes has a patchset ('Optimize mremap during mutual
     alignment within PMD') which fixes an obscure issue with mremap()'s
     pagetable handling during a subsequent exec(), based upon an
     implementation which Linus suggested

   - More DAMON/DAMOS maintenance and feature work from SeongJae Park i
     the following patch series:

	mm/damon: misc fixups for documents, comments and its tracepoint
	mm/damon: add a tracepoint for damos apply target regions
	mm/damon: provide pseudo-moving sum based access rate
	mm/damon: implement DAMOS apply intervals
	mm/damon/core-test: Fix memory leaks in core-test
	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval

   - In the series 'Do not try to access unaccepted memory' Adrian
     Hunter provides some fixups for the recently-added 'unaccepted
     memory' feature. To increase the feature's checking coverage. 'Plug
     a few gaps where RAM is exposed without checking if it is
     unaccepted memory'

   - In the series 'cleanups for lockless slab shrink' Qi Zheng has done
     some maintenance work which is preparation for the lockless slab
     shrinking code

   - Qi Zheng has redone the earlier (and reverted) attempt to make slab
     shrinking lockless in the series 'use refcount+RCU method to
     implement lockless slab shrink'

   - David Hildenbrand contributes some maintenance work for the rmap
     code in the series 'Anon rmap cleanups'

   - Kefeng Wang does more folio conversions and some maintenance work
     in the migration code. Series 'mm: migrate: more folio conversion
     and unification'

   - Matthew Wilcox has fixed an issue in the buffer_head code which was
     causing long stalls under some heavy memory/IO loads. Some cleanups
     were added on the way. Series 'Add and use bdev_getblk()'

   - In the series 'Use nth_page() in place of direct struct page
     manipulation' Zi Yan has fixed a potential issue with the direct
     manipulation of hugetlb page frames

   - In the series 'mm: hugetlb: Skip initialization of gigantic tail
     struct pages if freed by HVO' has improved our handling of gigantic
     pages in the hugetlb vmmemmep optimizaton code. This provides
     significant boot time improvements when significant amounts of
     gigantic pages are in use

   - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code
     rationalization and folio conversions in the hugetlb code

   - Yin Fengwei has improved mlock()'s handling of large folios in the
     series 'support large folio for mlock'

   - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has
     added statistics for memcg v1 users which are available (and
     useful) under memcg v2

   - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
     prctl so that userspace may direct the kernel to not automatically
     propagate the denial to child processes. The series is named 'MDWE
     without inheritance'

   - Kefeng Wang has provided the series 'mm: convert numa balancing
     functions to use a folio' which does what it says

   - In the series 'mm/ksm: add fork-exec support for prctl' Stefan
     Roesch makes is possible for a process to propagate KSM treatment
     across exec()

   - Huang Ying has enhanced memory tiering's calculation of memory
     distances. This is used to permit the dax/kmem driver to use 'high
     bandwidth memory' in addition to Optane Data Center Persistent
     Memory Modules (DCPMM). The series is named 'memory tiering:
     calculate abstract distance based on ACPI HMAT'

   - In the series 'Smart scanning mode for KSM' Stefan Roesch has
     optimized KSM by teaching it to retain and use some historical
     information from previous scans

   - Yosry Ahmed has fixed some inconsistencies in memcg statistics in
     the series 'mm: memcg: fix tracking of pending stats updates
     values'

   - In the series 'Implement IOCTL to get and optionally clear info
     about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap
     which permits us to atomically read-then-clear page softdirty
     state. This is mainly used by CRIU

   - Hugh Dickins contributed the series 'shmem,tmpfs: general
     maintenance', a bunch of relatively minor maintenance tweaks to
     this code

   - Matthew Wilcox has increased the use of the VMA lock over
     file-backed page faults in the series 'Handle more faults under the
     VMA lock'. Some rationalizations of the fault path became possible
     as a result

   - In the series 'mm/rmap: convert page_move_anon_rmap() to
     folio_move_anon_rmap()' David Hildenbrand has implemented some
     cleanups and folio conversions

   - In the series 'various improvements to the GUP interface' Lorenzo
     Stoakes has simplified and improved the GUP interface with an eye
     to providing groundwork for future improvements

   - Andrey Konovalov has sent along the series 'kasan: assorted fixes
     and improvements' which does those things

   - Some page allocator maintenance work from Kemeng Shi in the series
     'Two minor cleanups to break_down_buddy_pages'

   - In thes series 'New selftest for mm' Breno Leitao has developed
     another MM self test which tickles a race we had between madvise()
     and page faults

   - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups
     and an optimization to the core pagecache code

   - Nhat Pham has added memcg accounting for hugetlb memory in the
     series 'hugetlb memcg accounting'

   - Cleanups and rationalizations to the pagemap code from Lorenzo
     Stoakes, in the series 'Abstract vma_merge() and split_vma()'

   - Audra Mitchell has fixed issues in the procfs page_owner code's new
     timestamping feature which was causing some misbehaviours. In the
     series 'Fix page_owner's use of free timestamps'

   - Lorenzo Stoakes has fixed the handling of new mappings of sealed
     files in the series 'permit write-sealed memfd read-only shared
     mappings'

   - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
     series 'Batch hugetlb vmemmap modification operations'

   - Some buffer_head folio conversions and cleanups from Matthew Wilcox
     in the series 'Finish the create_empty_buffers() transition'

   - As a page allocator performance optimization Huang Ying has added
     automatic tuning to the allocator's per-cpu-pages feature, in the
     series 'mm: PCP high auto-tuning'

   - Roman Gushchin has contributed the patchset 'mm: improve
     performance of accounted kernel memory allocations' which improves
     their performance by ~30% as measured by a micro-benchmark

   - folio conversions from Kefeng Wang in the series 'mm: convert page
     cpupid functions to folios'

   - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about
     kmemleak'

   - Qi Zheng has improved our handling of memoryless nodes by keeping
     them off the allocation fallback list. This is done in the series
     'handle memoryless nodes more appropriately'

   - khugepaged conversions from Vishal Moola in the series 'Some
     khugepaged folio conversions'"

[ bcachefs conflicts with the dynamically allocated shrinkers have been
  resolved as per Stephen Rothwell in

     https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/

  with help from Qi Zheng.

  The clone3 test filtering conflict was half-arsed by yours truly ]

* tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits)
  mm/damon/sysfs: update monitoring target regions for online input commit
  mm/damon/sysfs: remove requested targets when online-commit inputs
  selftests: add a sanity check for zswap
  Documentation: maple_tree: fix word spelling error
  mm/vmalloc: fix the unchecked dereference warning in vread_iter()
  zswap: export compression failure stats
  Documentation: ubsan: drop "the" from article title
  mempolicy: migration attempt to match interleave nodes
  mempolicy: mmap_lock is not needed while migrating folios
  mempolicy: alloc_pages_mpol() for NUMA policy without vma
  mm: add page_rmappable_folio() wrapper
  mempolicy: remove confusing MPOL_MF_LAZY dead code
  mempolicy: mpol_shared_policy_init() without pseudo-vma
  mempolicy trivia: use pgoff_t in shared mempolicy tree
  mempolicy trivia: slightly more consistent naming
  mempolicy trivia: delete those ancient pr_debug()s
  mempolicy: fix migrate_pages(2) syscall return nr_failed
  kernfs: drop shared NUMA mempolicy hooks
  hugetlbfs: drop shared NUMA mempolicy pretence
  mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()
  ...
2023-11-02 19:38:47 -10:00
Jan Kara
e340dd63f6
xfs: Convert to bdev_open_by_path()
Convert xfs to use bdev_open_by_path() and pass the handle around.

CC: "Darrick J. Wong" <djwong@kernel.org>
CC: linux-xfs@vger.kernel.org
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-28-jack@suse.cz
Acked-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28 13:29:21 +02:00
Qi Zheng
17e7a00e60 xfs: dynamically allocate the xfs-buf shrinker
In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the xfs-buf shrinker, so that it can be freed
asynchronously via RCU. Then it doesn't need to wait for RCU read-side
critical section when releasing the struct xfs_buftarg.

Link: https://lkml.kernel.org/r/20230911094444.68966-35-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sean Paul <sean@poorly.run>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Song Liu <song@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:32:26 -07:00
Linus Torvalds
53ea7f624f New code for 6.6:
* Chandan Babu will be taking over as the XFS release manager.  He has
    reviewed all the patches that are in this branch, though I'm signing
    the branch one last time since I'm still technically maintainer. :P
  * Create a maintainer entry profile for XFS in which we lay out the
    various roles that I have played for many years.  Aside from release
    manager, the remaining roles are as yet unfilled.
  * Start merging online repair -- we now have in-memory pageable memory
    for staging btrees, a bunch of pending fixes, and we've started the
    process of refactoring the scrub support code to support more of
    repair.  In particular, reaping of old blocks from damaged structures.
  * Scrub the realtime summary file.
  * Fix a bug where scrub's quota iteration only ever returned the root
    dquot.  Oooops.
  * Fix some typos.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-6.6-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Chandan Babu:

 - Chandan Babu will be taking over as the XFS release manager. He has
   reviewed all the patches that are in this branch, though I'm signing
   the branch one last time since I'm still technically maintainer. :P

 - Create a maintainer entry profile for XFS in which we lay out the
   various roles that I have played for many years.  Aside from release
   manager, the remaining roles are as yet unfilled.

 - Start merging online repair -- we now have in-memory pageable memory
   for staging btrees, a bunch of pending fixes, and we've started the
   process of refactoring the scrub support code to support more of
   repair.  In particular, reaping of old blocks from damaged structures.

 - Scrub the realtime summary file.

 - Fix a bug where scrub's quota iteration only ever returned the root
   dquot.  Oooops.

 - Fix some typos.

[ Pull request from Chandan Babu, but signed tag and description from
  Darrick Wong, thus the first person singular above is Darrick, not
  Chandan ]

* tag 'xfs-6.6-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (37 commits)
  fs/xfs: Fix typos in comments
  xfs: fix dqiterate thinko
  xfs: don't check reflink iflag state when checking cow fork
  xfs: simplify returns in xchk_bmap
  xfs: rewrite xchk_inode_is_allocated to work properly
  xfs: hide xfs_inode_is_allocated in scrub common code
  xfs: fix agf_fllast when repairing an empty AGFL
  xfs: allow userspace to rebuild metadata structures
  xfs: clear pagf_agflreset when repairing the AGFL
  xfs: allow the user to cancel repairs before we start writing
  xfs: don't complain about unfixed metadata when repairs were injected
  xfs: implement online scrubbing of rtsummary info
  xfs: always rescan allegedly healthy per-ag metadata after repair
  xfs: move the realtime summary file scrubber to a separate source file
  xfs: wrap ilock/iunlock operations on sc->ip
  xfs: get our own reference to inodes that we want to scrub
  xfs: track usage statistics of online fsck
  xfs: improve xfarray quicksort pivot
  xfs: create scaffolding for creating debugfs entries
  xfs: cache pages used for xfarray quicksort convergence
  ...
2023-08-30 12:34:12 -07:00
Christoph Hellwig
2ea6f68932 fs: use the super_block as holder when mounting file systems
The file system type is not a very useful holder as it doesn't allow us
to go back to the actual file system instance.  Pass the super_block instead
which is useful when passed back to the file system driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <20230802154131.2221419-7-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11 13:15:03 +02:00
Darrick J. Wong
9ed851f695 xfs: allow scanning ranges of the buffer cache for live buffers
After an online repair, we need to invalidate buffers representing the
blocks from the old metadata that we're replacing.  It's possible that
parts of a tree that were previously cached in memory are no longer
accessible due to media failure or other corruption on interior nodes,
so repair figures out the old blocks from the reverse mapping data and
scans the buffer cache directly.

In other words, online fsck needs to find all the live (i.e. non-stale)
buffers for a range of fsblocks so that it can invalidate them.

Unfortunately, the current buffer cache code triggers asserts if the
rhashtable lookup finds a non-stale buffer of a different length than
the key we searched for.  For regular operation this is desirable, but
for this repair procedure, we don't care since we're going to forcibly
stale the buffer anyway.  Add an internal lookup flag to avoid the
assert.  Skip buffers that are already XBF_STALE.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-08-10 07:48:03 -07:00
Christoph Hellwig
35a93b148b xfs: close the external block devices in xfs_mount_free
blkdev_put must not be called under sb->s_umount to avoid a lock order
reversal with disk->open_mutex.  Move closing the buftargs into ->kill_sb
to archive that.  Note that the flushing of the disk caches and
block device mapping invalidated needs to stay in ->put_super as the main
block device is closed in kill_block_super already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Message-Id: <20230809220545.1308228-7-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-10 10:34:54 +02:00
Christoph Hellwig
41233576e9 xfs: close the RT and log block devices in xfs_free_buftarg
Closing the block devices logically belongs into xfs_free_buftarg,  So
instead of open coding it in the caller move it there and add a check
for the s_bdev so that the main device isn't close as that's done by the
VFS helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Message-Id: <20230809220545.1308228-6-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-10 10:34:54 +02:00
Yosry Ahmed
c7b23b68e2 mm: vmscan: refactor updating current->reclaim_state
During reclaim, we keep track of pages reclaimed from other means than
LRU-based reclaim through scan_control->reclaim_state->reclaimed_slab,
which we stash a pointer to in current task_struct.

However, we keep track of more than just reclaimed slab pages through
this.  We also use it for clean file pages dropped through pruned inodes,
and xfs buffer pages freed.  Rename reclaimed_slab to reclaimed, and add a
helper function that wraps updating it through current, so that future
changes to this logic are contained within include/linux/swap.h.

Link: https://lkml.kernel.org/r/20230413104034.1086717-4-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:10 -07:00
Darrick J. Wong
032e160305 xfs: invalidate block device page cache during unmount
Every now and then I see fstests failures on aarch64 (64k pages) that
trigger on the following sequence:

mkfs.xfs $dev
mount $dev $mnt
touch $mnt/a
umount $mnt
xfs_db -c 'path /a' -c 'print' $dev

99% of the time this succeeds, but every now and then xfs_db cannot find
/a and fails.  This turns out to be a race involving udev/blkid, the
page cache for the block device, and the xfs_db process.

udev is triggered whenever anyone closes a block device or unmounts it.
The default udev rules invoke blkid to read the fs super and create
symlinks to the bdev under /dev/disk.  For this, it uses buffered reads
through the page cache.

xfs_db also uses buffered reads to examine metadata.  There is no
coordination between xfs_db and udev, which means that they can run
concurrently.  Note there is no coordination between the kernel and
blkid either.

On a system with 64k pages, the page cache can cache the superblock and
the root inode (and hence the root dir) with the same 64k page.  If
udev spawns blkid after the mkfs and the system is busy enough that it
is still running when xfs_db starts up, they'll both read from the same
page in the pagecache.

The unmount writes updated inode metadata to disk directly.  The XFS
buffer cache does not use the bdev pagecache, nor does it invalidate the
pagecache on umount.  If the above scenario occurs, the pagecache no
longer reflects what's on disk, xfs_db reads the stale metadata, and
fails to find /a.  Most of the time this succeeds because closing a bdev
invalidates the page cache, but when processes race, everyone loses.

Fix the problem by invalidating the bdev pagecache after flushing the
bdev, so that xfs_db will see up to date metadata.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-30 08:55:18 -08:00
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
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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
Linus Torvalds
b2a88c212e New code for 5.20:
- Improve scalability of the XFS log by removing spinlocks and global
   synchronization points.
 - Add security labels to whiteout inodes to match the other filesystems.
 - Clean up per-ag pointer passing to simplify call sites.
 - Reduce verifier overhead by precalculating more AG geometry.
 - Implement fast-path lockless lookups in the buffer cache to reduce
   spinlock hammering.
 - Make attr forks a permanent part of the inode structure to fix a UAF
   bug and because most files these days tend to have security labels and
   soon will have parent pointers too.
 - Clean up XFS_IFORK_Q usage and give it a better name.
 - Fix more UAF bugs in the xattr code.
 - SOB my tags.
 - Fix some typos in the timestamp range documentation.
 - Fix a few more memory leaks.
 - Code cleanups and typo fixes.
 - Fix an unlocked inode fork pointer access in getbmap.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "The biggest changes for this release are the log scalability
  improvements, lockless lookups for the buffer cache, and making the
  attr fork a permanent part of the incore inode in preparation for
  directory parent pointers.

  There's also a bunch of bug fixes that have accumulated since -rc5. I
  might send you a second pull request with some more bug fixes that I'm
  still working on.

  Once the merge window ends, I will hand maintainership back to Dave
  Chinner until the 6.1-rc1 release so that I can conduct the design
  review for the online fsck feature, and try to get it merged.

  Summary:

   - Improve scalability of the XFS log by removing spinlocks and global
     synchronization points.

   - Add security labels to whiteout inodes to match the other
     filesystems.

   - Clean up per-ag pointer passing to simplify call sites.

   - Reduce verifier overhead by precalculating more AG geometry.

   - Implement fast-path lockless lookups in the buffer cache to reduce
     spinlock hammering.

   - Make attr forks a permanent part of the inode structure to fix a
     UAF bug and because most files these days tend to have security
     labels and soon will have parent pointers too.

   - Clean up XFS_IFORK_Q usage and give it a better name.

   - Fix more UAF bugs in the xattr code.

   - SOB my tags.

   - Fix some typos in the timestamp range documentation.

   - Fix a few more memory leaks.

   - Code cleanups and typo fixes.

   - Fix an unlocked inode fork pointer access in getbmap"

* tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (61 commits)
  xfs: delete extra space and tab in blank line
  xfs: fix NULL pointer dereference in xfs_getbmap()
  xfs: Fix typo 'the the' in comment
  xfs: Fix comment typo
  xfs: don't leak memory when attr fork loading fails
  xfs: fix for variable set but not used warning
  xfs: xfs_buf cache destroy isn't RCU safe
  xfs: delete unnecessary NULL checks
  xfs: fix comment for start time value of inode with bigtime enabled
  xfs: fix use-after-free in xattr node block inactivation
  xfs: lockless buffer lookup
  xfs: remove a superflous hash lookup when inserting new buffers
  xfs: reduce the number of atomic when locking a buffer after lookup
  xfs: merge xfs_buf_find() and xfs_buf_get_map()
  xfs: break up xfs_buf_find() into individual pieces
  xfs: add in-memory iunlink log item
  xfs: add log item precommit operation
  xfs: combine iunlink inode update functions
  xfs: clean up xfs_iunlink_update_inode()
  xfs: double link the unlinked inode list
  ...
2022-08-04 20:19:16 -07:00
Dave Chinner
231f91ab50 xfs: xfs_buf cache destroy isn't RCU safe
Darrick and Sachin Sant reported that xfs/435 and xfs/436 would
report an non-empty xfs_buf slab on module remove. This isn't easily
to reproduce, but is clearly a side effect of converting the buffer
caceh to RUC freeing and lockless lookups. Sachin bisected and
Darrick hit it when testing the patchset directly.

Turns out that the xfs_buf slab is not destroyed when all the other
XFS slab caches are destroyed. Instead, it's got it's own little
wrapper function that gets called separately, and so it doesn't have
an rcu_barrier() call in it that is needed to drain all the rcu
callbacks before the slab is destroyed.

Fix it by removing the xfs_buf_init/terminate wrappers that just
allocate and destroy the xfs_buf slab, and move them to the same
place that all the other slab caches are set up and destroyed.

Reported-and-tested-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 298f342245 ("xfs: lockless buffer lookup")
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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-20 16:40:39 -07:00
Shiyang Ruan
6f643c57d5 xfs: implement ->notify_failure() for XFS
Introduce xfs_notify_failure.c to handle failure related works, such as
implement ->notify_failure(), register/unregister dax holder in xfs, and
so on.

If the rmap feature of XFS enabled, we can query it to find files and
metadata which are associated with the corrupt data.  For now all we do is
kill processes with that file mapped into their address spaces, but future
patches could actually do something about corrupt metadata.

After that, the memory failure needs to notify the processes who are using
those files.

Link: https://lkml.kernel.org/r/20220603053738.1218681-7-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
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>
2022-07-17 17:14:30 -07:00
Shiyang Ruan
8012b86608 dax: introduce holder for dax_device
Patch series "v14 fsdax-rmap + v11 fsdax-reflink", v2.

The patchset fsdax-rmap is aimed to support shared pages tracking for
fsdax.

It moves owner tracking from dax_assocaite_entry() to pmem device driver,
by introducing an interface ->memory_failure() for struct pagemap.  This
interface is called by memory_failure() in mm, and implemented by pmem
device.

Then call holder operations to find the filesystem which the corrupted
data located in, and call filesystem handler to track files or metadata
associated with this page.

Finally we are able to try to fix the corrupted data in filesystem and do
other necessary processing, such as killing processes who are using the
files affected.

The call trace is like this:
memory_failure()
|* fsdax case
|------------
|pgmap->ops->memory_failure()      => pmem_pgmap_memory_failure()
| dax_holder_notify_failure()      =>
|  dax_device->holder_ops->notify_failure() =>
|                                     - xfs_dax_notify_failure()
|  |* xfs_dax_notify_failure()
|  |--------------------------
|  |   xfs_rmap_query_range()
|  |    xfs_dax_failure_fn()
|  |    * corrupted on metadata
|  |       try to recover data, call xfs_force_shutdown()
|  |    * corrupted on file data
|  |       try to recover data, call mf_dax_kill_procs()
|* normal case
|-------------
|mf_generic_kill_procs()


The patchset fsdax-reflink attempts to add CoW support for fsdax, and
takes XFS, which has both reflink and fsdax features, as an example.

One of the key mechanisms needed to be implemented in fsdax is CoW.  Copy
the data from srcmap before we actually write data to the destination
iomap.  And we just copy range in which data won't be changed.

Another mechanism is range comparison.  In page cache case, readpage() is
used to load data on disk to page cache in order to be able to compare
data.  In fsdax case, readpage() does not work.  So, we need another
compare data with direct access support.

With the two mechanisms implemented in fsdax, we are able to make reflink
and fsdax work together in XFS.


This patch (of 14):

To easily track filesystem from a pmem device, we introduce a holder for
dax_device structure, and also its operation.  This holder is used to
remember who is using this dax_device:

 - When it is the backend of a filesystem, the holder will be the
   instance of this filesystem.
 - When this pmem device is one of the targets in a mapped device, the
   holder will be this mapped device.  In this case, the mapped device
   has its own dax_device and it will follow the first rule.  So that we
   can finally track to the filesystem we needed.

The holder and holder_ops will be set when filesystem is being mounted,
or an target device is being activated.

Link: https://lkml.kernel.org/r/20220603053738.1218681-1-ruansy.fnst@fujitsu.com
Link: https://lkml.kernel.org/r/20220603053738.1218681-2-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.wiliams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:30 -07:00
Bart Van Assche
d03025aef8 fs/xfs: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for the
combination of a request operation with request flags.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-63-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-14 12:14:33 -06:00
Dave Chinner
298f342245 xfs: lockless buffer lookup
Now that we have a standalone fast path for buffer lookup, we can
easily convert it to use rcu lookups. When we continually hammer the
buffer cache with trylock lookups, we end up with a huge amount of
lock contention on the per-ag buffer hash locks:

-   92.71%     0.05%  [kernel]                  [k] xfs_inodegc_worker
   - 92.67% xfs_inodegc_worker
      - 92.13% xfs_inode_unlink
         - 91.52% xfs_inactive_ifree
            - 85.63% xfs_read_agi
               - 85.61% xfs_trans_read_buf_map
                  - 85.59% xfs_buf_read_map
                     - xfs_buf_get_map
                        - 85.55% xfs_buf_find
                           - 72.87% _raw_spin_lock
                              - do_raw_spin_lock
                                   71.86% __pv_queued_spin_lock_slowpath
                           - 8.74% xfs_buf_rele
                              - 7.88% _raw_spin_lock
                                 - 7.88% do_raw_spin_lock
                                      7.63% __pv_queued_spin_lock_slowpath
                           - 1.70% xfs_buf_trylock
                              - 1.68% down_trylock
                                 - 1.41% _raw_spin_lock_irqsave
                                    - 1.39% do_raw_spin_lock
                                         __pv_queued_spin_lock_slowpath
                           - 0.76% _raw_spin_unlock
                                0.75% do_raw_spin_unlock

This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.

We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by converting the lookup
fast path to leverages the rhashtable's ability to do rcu protected
lookups.

We avoid races with the buffer release path by using
atomic_inc_not_zero() on the buffer hold count. Any buffer that is
in the LRU will have a non-zero count, thereby allowing the lockless
fast path to be taken in most cache hit situations. If the buffer
hold count is zero, then it is likely going through the release path
so in that case we fall back to the existing lookup miss slow path.

The slow path will then do an atomic lookup and insert under the
buffer hash lock and hence serialise correctly against buffer
release freeing the buffer.

The use of rcu protected lookups means that buffer handles now need
to be freed by RCU callbacks (same as inodes). We still free the
buffer pages before the RCU callback - we won't be trying to access
them at all on a buffer that has zero references - but we need the
buffer handle itself to be present for the entire rcu protected read
side to detect a zero hold count correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:05:07 +10:00
Dave Chinner
32dd4f9c50 xfs: remove a superflous hash lookup when inserting new buffers
Currently on the slow path insert we repeat the initial hash table
lookup before we attempt the insert, resulting in a two traversals
of the hash table to ensure the insert is valid. The rhashtable API
provides a method for an atomic lookup and insert operation, so we
can avoid one of the hash table traversals by using this method.

Adapted from a large patch containing this optimisation by Christoph
Hellwig.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:43 +10:00
Dave Chinner
d8d9bbb0ee xfs: reduce the number of atomic when locking a buffer after lookup
Avoid an extra atomic operation in the non-trylock case by only
doing a trylock if the XBF_TRYLOCK flag is set. This follows the
pattern in the IO path with NOWAIT semantics where the
"trylock-fail-lock" path showed 5-10% reduced throughput compared to
just using single lock call when not under NOWAIT conditions. So
make that same change here, too.

See commit 942491c9e6 ("xfs: fix AIM7 regression") for details.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:38 +10:00
Dave Chinner
348000804a xfs: merge xfs_buf_find() and xfs_buf_get_map()
Now that we factored xfs_buf_find(), we can start separating into
distinct fast and slow paths from xfs_buf_get_map(). We start by
moving the lookup map and perag setup to _get_map(), and then move
all the specifics of the fast path lookup into xfs_buf_lookup()
and call it directly from _get_map(). We the move all the slow path
code to xfs_buf_find_insert(), which is now also called directly
from _get_map(). As such, xfs_buf_find() now goes away.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:31 +10:00
Dave Chinner
de67dc5754 xfs: break up xfs_buf_find() into individual pieces
xfs_buf_find() is made up of three main parts: lookup, insert and
locking. The interactions with xfs_buf_get_map() require it to be
called twice - once for a pure lookup, and again on lookup failure
so the insert path can be run. We want to simplify this down a lot,
so split it into a fast path lookup, a slow path insert and a "lock
the found buffer" helper. This will then let us integrate these
operations more effectively into xfs_buf_get_map() in future
patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:02:46 +10:00
Dave Chinner
85c73bf726 xfs: rework xfs_buf_incore() API
Make it consistent with the other buffer APIs to return a error and
the buffer is placed in a parameter.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-07 22:05:18 +10:00
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
b9b3fe152e xfs: convert buffer flags to unsigned.
5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned. This manifests as a compiler error such as:

/kisskb/src/fs/xfs/./xfs_trace.h:432:2: note: in expansion of macro 'TP_printk'
  TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d "
  ^
/kisskb/src/fs/xfs/./xfs_trace.h:440:5: note: in expansion of macro '__print_flags'
     __print_flags(__entry->flags, "|", XFS_BUF_FLAGS),
     ^
/kisskb/src/fs/xfs/xfs_buf.h:67:4: note: in expansion of macro 'XBF_UNMAPPED'
  { XBF_UNMAPPED,  "UNMAPPED" }
    ^
/kisskb/src/fs/xfs/./xfs_trace.h:440:40: note: in expansion of macro 'XFS_BUF_FLAGS'
     __print_flags(__entry->flags, "|", XFS_BUF_FLAGS),
                                        ^
/kisskb/src/fs/xfs/./xfs_trace.h: In function 'trace_raw_output_xfs_buf_flags_class':
/kisskb/src/fs/xfs/xfs_buf.h:46:23: error: initializer element is not constant
 #define XBF_UNMAPPED  (1 << 31)/* do not map the buffer */

as __print_flags assigns XFS_BUF_FLAGS to a structure that uses an
unsigned long for the flag. Since this results in the value of
XBF_UNMAPPED causing a signed integer overflow, the result is
technically undefined behavior, which gcc-5 does not accept as an
integer constant.

This is based on a patch from Arnd Bergman <arnd@arndb.de>.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
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>
2022-04-21 08:44:59 +10:00
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
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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
Linus Torvalds
3bf03b9a08 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs

 - Most the MM patches which precede the patches in Willy's tree: kasan,
   pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
   sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb,
   userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp,
   cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap,
   zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits)
  mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()
  Docs/ABI/testing: add DAMON sysfs interface ABI document
  Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface
  selftests/damon: add a test for DAMON sysfs interface
  mm/damon/sysfs: support DAMOS stats
  mm/damon/sysfs: support DAMOS watermarks
  mm/damon/sysfs: support schemes prioritization
  mm/damon/sysfs: support DAMOS quotas
  mm/damon/sysfs: support DAMON-based Operation Schemes
  mm/damon/sysfs: support the physical address space monitoring
  mm/damon/sysfs: link DAMON for virtual address spaces monitoring
  mm/damon: implement a minimal stub for sysfs-based DAMON interface
  mm/damon/core: add number of each enum type values
  mm/damon/core: allow non-exclusive DAMON start/stop
  Docs/damon: update outdated term 'regions update interval'
  Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling
  Docs/vm/damon: call low level monitoring primitives the operations
  mm/damon: remove unnecessary CONFIG_DAMON option
  mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()
  mm/damon/dbgfs-test: fix is_target_id() change
  ...
2022-03-22 16:11:53 -07:00
NeilBrown
b9b1335e64 remove bdi_congested() and wb_congested() and related functions
These functions are no longer useful as no BDIs report congestions any
more.

Removing the test on bdi_write_contested() in current_may_throttle()
could cause a small change in behaviour, but only when PF_LOCAL_THROTTLE
is set.

So replace the calls by 'false' and simplify the code - and remove the
functions.

[akpm@linux-foundation.org: fix build]

Link: https://lkml.kernel.org/r/164549983742.9187.2570198746005819592.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>	[nilfs]
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:01 -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
Dave Chinner
dbd0f52993 xfs: check buffer pin state after locking in delwri_submit
AIL flushing can get stuck here:

[316649.005769] INFO: task xfsaild/pmem1:324525 blocked for more than 123 seconds.
[316649.007807]       Not tainted 5.17.0-rc6-dgc+ #975
[316649.009186] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[316649.011720] task:xfsaild/pmem1   state:D stack:14544 pid:324525 ppid:     2 flags:0x00004000
[316649.014112] Call Trace:
[316649.014841]  <TASK>
[316649.015492]  __schedule+0x30d/0x9e0
[316649.017745]  schedule+0x55/0xd0
[316649.018681]  io_schedule+0x4b/0x80
[316649.019683]  xfs_buf_wait_unpin+0x9e/0xf0
[316649.021850]  __xfs_buf_submit+0x14a/0x230
[316649.023033]  xfs_buf_delwri_submit_buffers+0x107/0x280
[316649.024511]  xfs_buf_delwri_submit_nowait+0x10/0x20
[316649.025931]  xfsaild+0x27e/0x9d0
[316649.028283]  kthread+0xf6/0x120
[316649.030602]  ret_from_fork+0x1f/0x30

in the situation where flushing gets preempted between the unpin
check and the buffer trylock under nowait conditions:

	blk_start_plug(&plug);
	list_for_each_entry_safe(bp, n, buffer_list, b_list) {
		if (!wait_list) {
			if (xfs_buf_ispinned(bp)) {
				pinned++;
				continue;
			}
Here >>>>>>
			if (!xfs_buf_trylock(bp))
				continue;

This means submission is stuck until something else triggers a log
force to unpin the buffer.

To get onto the delwri list to begin with, the buffer pin state has
already been checked, and hence it's relatively rare we get a race
between flushing and encountering a pinned buffer in delwri
submission to begin with. Further, to increase the pin count the
buffer has to be locked, so the only way we can hit this race
without failing the trylock is to be preempted between the pincount
check seeing zero and the trylock being run.

Hence to avoid this problem, just invert the order of trylock vs
pin check. We shouldn't hit that many pinned buffers here, so
optimising away the trylock for pinned buffers should not matter for
performance at all.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Christoph Hellwig
07888c665b block: pass a block_device and opf to bio_alloc
Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02 07:49:59 -07:00