Commit Graph

1026 Commits

Author SHA1 Message Date
Johannes Weiner
d5d39c707a mm: cachestat: fix two shmem bugs
When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:

1) A swapin error can have resulted in a poisoned swap entry in the
   shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
   will result in an out-of-bounds access to swapper_spaces[].

   Validate the entry with non_swap_entry() before going further.

2) When we find a valid swap entry in the shmem's inode, the shadow
   entry in the swapcache might not exist yet: swap IO is still in
   progress and we're before __remove_mapping; swapin, invalidation,
   or swapoff have removed the shadow from swapcache after we saw the
   shmem swap entry.

   This will send a NULL to workingset_test_recent(). The latter
   purely operates on pointer bits, so it won't crash - node 0, memcg
   ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
   bogus test. In theory that could result in a false "recently
   evicted" count.

   Such a false positive wouldn't be the end of the world. But for
   code clarity and (future) robustness, be explicit about this case.

   Bail on get_shadow_from_swap_cache() returning NULL.

Link: https://lkml.kernel.org/r/20240315095556.GC581298@cmpxchg.org
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Chengming Zhou <chengming.zhou@linux.dev>	[Bug #1]
Reported-by: Jann Horn <jannh@google.com>		[Bug #2]
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>				[v6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-26 11:07:20 -07:00
Linus Torvalds
902861e34c - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory.  Series
   "implement "memmap on memory" feature on s390".
 
 - More folio conversions from Matthew Wilcox in the series
 
 	"Convert memcontrol charge moving to use folios"
 	"mm: convert mm counter to take a folio"
 
 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes.  The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".
 
 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.
 
 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools".  Measured improvements are modest.
 
 - zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
   zswap: simplify zswap_swapoff()".
 
 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is hotplugged
   as system memory.
 
 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.
 
 - More DAMON work from SeongJae Park in the series
 
 	"mm/damon: make DAMON debugfs interface deprecation unignorable"
 	"selftests/damon: add more tests for core functionalities and corner cases"
 	"Docs/mm/damon: misc readability improvements"
 	"mm/damon: let DAMOS feeds and tame/auto-tune itself"
 
 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving policy
   wherein we allocate memory across nodes in a weighted fashion rather
   than uniformly.  This is beneficial in heterogeneous memory environments
   appearing with CXL.
 
 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
 
 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".
 
 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format.  Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.
 
 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP".  Mainly
   targeted at arm64, this significantly speeds up fork() when the process
   has a large number of pte-mapped folios.
 
 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP".  It
   implements batching during munmap() and other pte teardown situations.
   The microbenchmark improvements are nice.
 
 - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
   Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings").  Kernel build times on arm64 improved nicely.  Ryan's series
   "Address some contpte nits" provides some followup work.
 
 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page faults.
   He has also added a reproducer under the selftest code.
 
 - In the series "selftests/mm: Output cleanups for the compaction test",
   Mark Brown did what the title claims.
 
 - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
 
 - Even more zswap material from Nhat Pham.  The series "fix and extend
   zswap kselftests" does as claimed.
 
 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
   our handling of DAX on archiecctures which have virtually aliasing data
   caches.  The arm architecture is the main beneficiary.
 
 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
   improvements in worst-case mmap_lock hold times during certain
   userfaultfd operations.
 
 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series
 
 	"page_owner: print stacks and their outstanding allocations"
 	"page_owner: Fixup and cleanup"
 
 - Uladzislau Rezki has contributed some vmalloc scalability improvements
   in his series "Mitigate a vmap lock contention".  It realizes a 12x
   improvement for a certain microbenchmark.
 
 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".
 
 - Some zsmalloc maintenance work from Chengming Zhou in the series
 
 	"mm/zsmalloc: fix and optimize objects/page migration"
 	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
 
 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0.  This a step along the path to implementaton of the merging of
   large anonymous folios.  The series is named "Enable >0 order folio
   memory compaction".
 
 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages() to
   an iterator".
 
 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".
 
 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios.  The
   series is named "Split a folio to any lower order folios".
 
 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.
 
 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".
 
 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which are
   configured to use large numbers of hugetlb pages.
 
 - Matthew Wilcox's series "PageFlags cleanups" does that.
 
 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also.  S390 is affected.
 
 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".
 
 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
 
 - Also, of course, many singleton patches to many things.  Please see
   the individual changelogs for details.
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Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...
2024-03-14 17:43:30 -07:00
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
Linus Torvalds
7ea65c89d8 vfs-6.9.misc
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Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Misc features, cleanups, and fixes for vfs and individual filesystems.

  Features:

   - Support idmapped mounts for hugetlbfs.

   - Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
     where the passed offset is ignored if the file is O_APPEND. The new
     flag allows a caller to enforce that the offset is honored to
     conform to posix even if the file was opened in append mode.

   - Move i_mmap_rwsem in struct address_space to avoid false sharing
     between i_mmap and i_mmap_rwsem.

   - Convert efs, qnx4, and coda to use the new mount api.

   - Add a generic is_dot_dotdot() helper that's used by various
     filesystems and the VFS code instead of open-coding it multiple
     times.

   - Recently we've added stable offsets which allows stable ordering
     when iterating directories exported through NFS on e.g., tmpfs
     filesystems. Originally an xarray was used for the offset map but
     that caused slab fragmentation issues over time. This switches the
     offset map to the maple tree which has a dense mode that handles
     this scenario a lot better. Includes tests.

   - Finally merge the case-insensitive improvement series Gabriel has
     been working on for a long time. This cleanly propagates case
     insensitive operations through ->s_d_op which in turn allows us to
     remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
     It also improves performance by trying a case-sensitive comparison
     first and then fallback to case-insensitive lookup if that fails.
     This also fixes a bug where overlayfs would be able to be mounted
     over a case insensitive directory which would lead to all sort of
     odd behaviors.

  Cleanups:

   - Make file_dentry() a simple accessor now that ->d_real() is
     simplified because of the backing file work we did the last two
     cycles.

   - Use the dedicated file_mnt_idmap helper in ntfs3.

   - Use smp_load_acquire/store_release() in the i_size_read/write
     helpers and thus remove the hack to handle i_size reads in the
     filemap code.

   - The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
     fs/

   - It's no longer necessary to perform a second built-in initramfs
     unpack call because we retain the contents of the previous
     extraction. Remove it.

   - Now that we have removed various allocators kfree_rcu() always
     works with kmem caches and kmalloc(). So simplify various places
     that only use an rcu callback in order to handle the kmem cache
     case.

   - Convert the pipe code to use a lockdep comparison function instead
     of open-coding the nesting making lockdep validation easier.

   - Move code into fs-writeback.c that was located in a header but can
     be made static as it's only used in that one file.

   - Rewrite the alignment checking iterators for iovec and bvec to be
     easier to read, and also significantly more compact in terms of
     generated code. This saves 270 bytes of text on x86-64 (with
     clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
     saves a bit of time for the same workload.

   - Switch various places to use KMEM_CACHE instead of
     kmem_cache_create().

   - Use inode_set_ctime_to_ts() in inode_set_ctime_current()

   - Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.

   - Various smaller cleanups for eventfds.

  Fixes:

   - Fix various comments and typos, and unneeded initializations.

   - Fix stack allocation hack for clang in the select code.

   - Improve dump_mapping() debug code on a best-effort basis.

   - Fix build errors in various selftests.

   - Avoid wrap-around instrumentation in various places.

   - Don't allow user namespaces without an idmapping to be used for
     idmapped mounts.

   - Fix sysv sb_read() call.

   - Fix fallback implementation of the get_name() export operation"

* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
  hugetlbfs: support idmapped mounts
  qnx4: convert qnx4 to use the new mount api
  fs: use inode_set_ctime_to_ts to set inode ctime to current time
  libfs: Drop generic_set_encrypted_ci_d_ops
  ubifs: Configure dentry operations at dentry-creation time
  f2fs: Configure dentry operations at dentry-creation time
  ext4: Configure dentry operations at dentry-creation time
  libfs: Add helper to choose dentry operations at mount-time
  libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
  fscrypt: Drop d_revalidate once the key is added
  fscrypt: Drop d_revalidate for valid dentries during lookup
  fscrypt: Factor out a helper to configure the lookup dentry
  ovl: Always reject mounting over case-insensitive directories
  libfs: Attempt exact-match comparison first during casefolded lookup
  efs: remove SLAB_MEM_SPREAD flag usage
  jfs: remove SLAB_MEM_SPREAD flag usage
  minix: remove SLAB_MEM_SPREAD flag usage
  openpromfs: remove SLAB_MEM_SPREAD flag usage
  proc: remove SLAB_MEM_SPREAD flag usage
  qnx6: remove SLAB_MEM_SPREAD flag usage
  ...
2024-03-11 09:38:17 -07:00
ZhangPeng
58f327f2ce filemap: avoid unnecessary major faults in filemap_fault()
A major fault occurred when using mlockall(MCL_CURRENT | MCL_FUTURE) in
application, which leading to an unexpected issue[1].

This is caused by temporarily cleared PTE during a read+clear/modify/write
update of the PTE, eg, do_numa_page()/change_pte_range().

For the data segment of the user-mode program, the global variable area is
a private mapping.  After the pagecache is loaded, the private anonymous
page is generated after the COW is triggered.  Mlockall can lock COW pages
(anonymous pages), but the original file pages cannot be locked and may be
reclaimed.  If the global variable (private anon page) is accessed when
vmf->pte is zeroed in numa fault, a file page fault will be triggered.  At
this time, the original private file page may have been reclaimed.  If the
page cache is not available at this time, a major fault will be triggered
and the file will be read, causing additional overhead.

This issue affects our traffic analysis service.  The inbound traffic is
heavy.  If a major fault occurs, the I/O schedule is triggered and the
original I/O is suspended.  Generally, the I/O schedule is 0.7 ms.  If
other applications are operating disks, the system needs to wait for more
than 10 ms.  However, the inbound traffic is heavy and the NIC buffer is
small.  As a result, packet loss occurs.  But the traffic analysis service
can't tolerate packet loss.

Fix this by holding PTL and rechecking the PTE in filemap_fault() before
triggering a major fault.  We do this check only if vma is VM_LOCKED to
reduce the performance impact in common scenarios.

In our product environment, there were 7 major faults every 12 hours. 
After the patch is applied, no major fault have been triggered.

Testing file page read and write page fault performance in ext4 and
ramdisk using will-it-scale[2] on a x86 physical machine.  The data is the
average change compared with the mainline after the patch is applied.  The
test results are within the range of fluctuation.  We do this check only
if vma is VM_LOCKED, therefore, no performance regressions is caused for
most common cases.

The test results are as follows:
                          processes processes_idle  threads threads_idle
ext4    private file write:  0.22%    0.26%           1.21%  -0.15%
ext4    private file  read:  0.03%    1.00%           1.39%   0.34%
ext4    shared  file write: -0.50%   -0.02%          -0.14%  -0.02%
ramdisk private file write:  0.07%    0.02%           0.53%   0.04%
ramdisk private file  read:  0.01%    1.60%          -0.32%  -0.02%

[1] https://lore.kernel.org/linux-mm/9e62fd9a-bee0-52bf-50a7-498fa17434ee@huawei.com/
[2] https://github.com/antonblanchard/will-it-scale/

Link: https://lkml.kernel.org/r/20240306083809.1236634-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06 13:04:20 -08:00
Matthew Wilcox (Oracle)
8897277acf mm: support order-1 folios in the page cache
Folios of order 1 have no space to store the deferred list.  This is not a
problem for the page cache as file-backed folios are never placed on the
deferred list.  All we need to do is prevent the core MM from touching the
deferred list for order 1 folios and remove the code which prevented us
from allocating order 1 folios.

Link: https://lore.kernel.org/linux-mm/90344ea7-4eec-47ee-5996-0c22f42d6a6a@google.com/
Link: https://lkml.kernel.org/r/20240226205534.1603748-3-zi.yan@sent.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04 17:01:19 -08:00
Andrew Morton
1f1183c4c0 merge mm-hotfixes-stable into mm-nonmm-stable to pick up stackdepot changes 2024-02-23 17:28:43 -08:00
Nhat Pham
3a75cb05d5 mm: cachestat: fix folio read-after-free in cache walk
In cachestat, we access the folio from the page cache's xarray to compute
its page offset, and check for its dirty and writeback flags.  However, we
do not hold a reference to the folio before performing these actions,
which means the folio can concurrently be released and reused as another
folio/page/slab.

Get around this altogether by just using xarray's existing machinery for
the folio page offsets and dirty/writeback states.

This changes behavior for tmpfs files to now always report zeroes in their
dirty and writeback counters.  This is okay as tmpfs doesn't follow
conventional writeback cache behavior: its pages get "cleaned" during
swapout, after which they're no longer resident etc.

Link: https://lkml.kernel.org/r/20240220153409.GA216065@cmpxchg.org
Fixes: cf264e1329 ("cachestat: implement cachestat syscall")
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>	[6.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:27:13 -08:00
Matthew Wilcox (Oracle)
5662400a9a mm: add pfn_swap_entry_folio()
Patch series "mm: convert mm counter to take a folio", v3.

Make sure all mm_counter() and mm_counter_file() callers have a folio,
then convert mm counter functions to take a folio, which saves some
compound_head() calls.


This patch (of 10):  

Thanks to the compound_head() hidden inside PageLocked(), this saves a
call to compound_head() over calling page_folio(pfn_swap_entry_to_page())

Link: https://lkml.kernel.org/r/20240111152429.3374566-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240111152429.3374566-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:03 -08:00
Hongbo Li
6212eb4d7a mm/filemap: avoid type conversion
The return type of function folio_test_hugetlb is bool type, there is no
need to assign it to an integer type.

Link: https://lkml.kernel.org/r/20240108044815.3291487-1-lihongbo22@huawei.com
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:02 -08:00
Christoph Hellwig
b64e74e95a mm: move mapping_set_update out of <linux/swap.h>
mapping_set_update is only used inside mm/.  Move mapping_set_update to
mm/internal.h and turn it into an inline function instead of a macro.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-21 11:36:50 +05:30
Baokun Li
4b944f8ef9 Revert "mm/filemap: avoid buffered read/write race to read inconsistent data"
This reverts commit e2c27b803b ("mm/filemap: avoid buffered read/write
race to read inconsistent data"). After making the i_size_read/write
helpers be smp_load_acquire/store_release(), it is already guaranteed that
changes to page contents are visible before we see increased inode size,
so the extra smp_rmb() in filemap_read() can be removed.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240124142857.4146716-3-libaokun1@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-25 17:23:51 +01:00
Linus Torvalds
16df6e07d6 vfs-6.8.netfs
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Merge tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull netfs updates from Christian Brauner:
 "This extends the netfs helper library that network filesystems can use
  to replace their own implementations. Both afs and 9p are ported. cifs
  is ready as well but the patches are way bigger and will be routed
  separately once this is merged. That will remove lots of code as well.

  The overal goal is to get high-level I/O and knowledge of the page
  cache and ouf of the filesystem drivers. This includes knowledge about
  the existence of pages and folios

  The pull request converts afs and 9p. This removes about 800 lines of
  code from afs and 300 from 9p. For 9p it is now possible to do writes
  in larger than a page chunks. Additionally, multipage folio support
  can be turned on for 9p. Separate patches exist for cifs removing
  another 2000+ lines. I've included detailed information in the
  individual pulls I took.

  Summary:

   - Add NFS-style (and Ceph-style) locking around DIO vs buffered I/O
     calls to prevent these from happening at the same time.

   - Support for direct and unbuffered I/O.

   - Support for write-through caching in the page cache.

   - O_*SYNC and RWF_*SYNC writes use write-through rather than writing
     to the page cache and then flushing afterwards.

   - Support for write-streaming.

   - Support for write grouping.

   - Skip reads for which the server could only return zeros or EOF.

   - The fscache module is now part of the netfs library and the
     corresponding maintainer entry is updated.

   - Some helpers from the fscache subsystem are renamed to mark them as
     belonging to the netfs library.

   - Follow-up fixes for the netfs library.

   - Follow-up fixes for the 9p conversion"

* tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (50 commits)
  netfs: Fix wrong #ifdef hiding wait
  cachefiles: Fix signed/unsigned mixup
  netfs: Fix the loop that unmarks folios after writing to the cache
  netfs: Fix interaction between write-streaming and cachefiles culling
  netfs: Count DIO writes
  netfs: Mark netfs_unbuffered_write_iter_locked() static
  netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs"
  netfs: Rearrange netfs_io_subrequest to put request pointer first
  9p: Use length of data written to the server in preference to error
  9p: Do a couple of cleanups
  9p: Fix initialisation of netfs_inode for 9p
  cachefiles: Fix __cachefiles_prepare_write()
  9p: Use netfslib read/write_iter
  afs: Use the netfs write helpers
  netfs: Export the netfs_sreq tracepoint
  netfs: Optimise away reads above the point at which there can be no data
  netfs: Implement a write-through caching option
  netfs: Provide a launder_folio implementation
  netfs: Provide a writepages implementation
  netfs, cachefiles: Pass upper bound length to allow expansion
  ...
2024-01-19 09:10:23 -08:00
Linus Torvalds
78273df7f6 header cleanups for 6.8
The goal is to get sched.h down to a type only header, so the main thing
 happening in this patchset is splitting out various _types.h headers and
 dependency fixups, as well as moving some things out of sched.h to
 better locations.
 
 This is prep work for the memory allocation profiling patchset which
 adds new sched.h interdepencencies.
 
 Testing - it's been in -next, and fixes from pretty much all
 architectures have percolated in - nothing major.
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Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs

Pull header cleanups from Kent Overstreet:
 "The goal is to get sched.h down to a type only header, so the main
  thing happening in this patchset is splitting out various _types.h
  headers and dependency fixups, as well as moving some things out of
  sched.h to better locations.

  This is prep work for the memory allocation profiling patchset which
  adds new sched.h interdepencencies"

* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
  Kill sched.h dependency on rcupdate.h
  kill unnecessary thread_info.h include
  Kill unnecessary kernel.h include
  preempt.h: Kill dependency on list.h
  rseq: Split out rseq.h from sched.h
  LoongArch: signal.c: add header file to fix build error
  restart_block: Trim includes
  lockdep: move held_lock to lockdep_types.h
  sem: Split out sem_types.h
  uidgid: Split out uidgid_types.h
  seccomp: Split out seccomp_types.h
  refcount: Split out refcount_types.h
  uapi/linux/resource.h: fix include
  x86/signal: kill dependency on time.h
  syscall_user_dispatch.h: split out *_types.h
  mm_types_task.h: Trim dependencies
  Split out irqflags_types.h
  ipc: Kill bogus dependency on spinlock.h
  shm: Slim down dependencies
  workqueue: Split out workqueue_types.h
  ...
2024-01-10 16:43:55 -08:00
David Hildenbrand
4d8f7418e8 mm/rmap: remove page_remove_rmap()
All callers are gone, let's remove it and some leftover traces.

Link: https://lkml.kernel.org/r/20231220224504.646757-33-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29 11:58:55 -08:00
David Howells
153a9961b5 netfs: Implement unbuffered/DIO write support
Implement support for unbuffered writes and direct I/O writes.  If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary.  DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.

Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-28 09:45:24 +00:00
David Howells
016dc8516a netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing.  The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.

The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method.  Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.

Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined.  As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.

In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-28 09:45:23 +00:00
Kent Overstreet
1e2f2d3199 Kill sched.h dependency on rcupdate.h
by moving cond_resched_rcu() to rcupdate_wait.h, we can kill another big
sched.h dependency.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-27 11:50:20 -05:00
Andrew Morton
a721aeac8b sync mm-stable with mm-hotfixes-stable to pick up depended-upon changes 2023-12-20 14:47:18 -08:00
Baokun Li
e2c27b803b mm/filemap: avoid buffered read/write race to read inconsistent data
The following concurrency may cause the data read to be inconsistent with
the data on disk:

             cpu1                           cpu2
------------------------------|------------------------------
                               // Buffered write 2048 from 0
                               ext4_buffered_write_iter
                                generic_perform_write
                                 copy_page_from_iter_atomic
                                 ext4_da_write_end
                                  ext4_da_do_write_end
                                   block_write_end
                                    __block_commit_write
                                     folio_mark_uptodate
// Buffered read 4096 from 0          smp_wmb()
ext4_file_read_iter                   set_bit(PG_uptodate, folio_flags)
 generic_file_read_iter            i_size_write // 2048
  filemap_read                     unlock_page(page)
   filemap_get_pages
    filemap_get_read_batch
    folio_test_uptodate(folio)
     ret = test_bit(PG_uptodate, folio_flags)
     if (ret)
      smp_rmb();
      // Ensure that the data in page 0-2048 is up-to-date.

                               // New buffered write 2048 from 2048
                               ext4_buffered_write_iter
                                generic_perform_write
                                 copy_page_from_iter_atomic
                                 ext4_da_write_end
                                  ext4_da_do_write_end
                                   block_write_end
                                    __block_commit_write
                                     folio_mark_uptodate
                                      smp_wmb()
                                      set_bit(PG_uptodate, folio_flags)
                                   i_size_write // 4096
                                   unlock_page(page)

   isize = i_size_read(inode) // 4096
   // Read the latest isize 4096, but without smp_rmb(), there may be
   // Load-Load disorder resulting in the data in the 2048-4096 range
   // in the page is not up-to-date.
   copy_page_to_iter
   // copyout 4096

In the concurrency above, we read the updated i_size, but there is no read
barrier to ensure that the data in the page is the same as the i_size at
this point, so we may copy the unsynchronized page out.  Hence adding the
missing read memory barrier to fix this.

This is a Load-Load reordering issue, which only occurs on some weak
mem-ordering architectures (e.g.  ARM64, ALPHA), but not on strong
mem-ordering architectures (e.g.  X86).  And theoretically the problem
doesn't only happen on ext4, filesystems that call filemap_read() but
don't hold inode lock (e.g.  btrfs, f2fs, ubifs ...) will have this
problem, while filesystems with inode lock (e.g.  xfs, nfs) won't have
this problem.

Link: https://lkml.kernel.org/r/20231213062324.739009-1-libaokun1@huawei.com
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: yangerkun <yangerkun@huawei.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 13:46:19 -08:00
Li zeming
a1748f85be mm: filemap: remove unnecessary iitialization of ret
The ret variable can be defined without assigning a value, as it is
assigned before use.

Link: https://lkml.kernel.org/r/20231205022954.101045-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12 10:57:07 -08:00
Minjie Du
8ff252663d mm/filemap: increase usage of folio_next_index() helper
Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index() in filemap_get_folios_contig().

Link: https://lkml.kernel.org/r/20231107024635.4512-1-duminjie@vivo.com
Signed-off-by: Minjie Du <duminjie@vivo.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:35 -08:00
Hugh Dickins
9aa1345d66 mm: fix oops when filemap_map_pmd() without prealloc_pte
syzbot reports oops in lockdep's __lock_acquire(), called from
__pte_offset_map_lock() called from filemap_map_pages(); or when I run the
repro, the oops comes in pmd_install(), called from filemap_map_pmd()
called from filemap_map_pages(), just before the __pte_offset_map_lock().

The problem is that filemap_map_pmd() has been assuming that when it finds
pmd_none(), a page table has already been prepared in prealloc_pte; and
indeed do_fault_around() has been careful to preallocate one there, when
it finds pmd_none(): but what if *pmd became none in between?

My 6.6 mods in mm/khugepaged.c, avoiding mmap_lock for write, have made it
easy for *pmd to be cleared while servicing a page fault; but even before
those, a huge *pmd might be zapped while a fault is serviced.

The difference in symptomatic stack traces comes from the "memory model"
in use: pmd_install() uses pmd_populate() uses page_to_pfn(): in some
models that is strict, and will oops on the NULL prealloc_pte; in other
models, it will construct a bogus value to be populated into *pmd, then
__pte_offset_map_lock() oops when trying to access split ptlock pointer
(or some other symptom in normal case of ptlock embedded not pointer).

Link: https://lore.kernel.org/linux-mm/20231115065506.19780-1-jose.pekkarinen@foxhound.fi/
Link: https://lkml.kernel.org/r/6ed0c50c-78ef-0719-b3c5-60c0c010431c@google.com
Fixes: f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-and-tested-by: syzbot+89edd67979b52675ddec@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/0000000000005e44550608a0806c@google.com/
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>,
Cc: José Pekkarinen <jose.pekkarinen@foxhound.fi>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>    [5.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-06 16:12:45 -08:00
Ryan Roberts
afccb0804f mm: more ptep_get() conversion
Commit c33c794828 ("mm: ptep_get() conversion") converted all (non-arch)
call sites to use ptep_get() instead of doing a direct dereference of the
pte.  Full rationale can be found in that commit's log.

Since then, three new call sites have snuck in, which directly dereference
the pte, so let's fix those up.

Unfortunately there is no reliable automated mechanism to catch these; I'm
relying on a combination of Coccinelle (which throws up a lot of false
positives) and some compiler magic to force a compiler error on
dereference (While this approach finds dereferences, it also yields a
non-booting kernel so can't be committed).

Link: https://lkml.kernel.org/r/20231114154945.490401-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-15 15:30:09 -08:00
Lorenzo Stoakes
e8e17ee90e mm: drop the assumption that VM_SHARED always implies writable
Patch series "permit write-sealed memfd read-only shared mappings", v4.

The man page for fcntl() describing memfd file seals states the following
about F_SEAL_WRITE:-

    Furthermore, trying to create new shared, writable memory-mappings via
    mmap(2) will also fail with EPERM.

With emphasis on 'writable'.  In turns out in fact that currently the
kernel simply disallows all new shared memory mappings for a memfd with
F_SEAL_WRITE applied, rendering this documentation inaccurate.

This matters because users are therefore unable to obtain a shared mapping
to a memfd after write sealing altogether, which limits their usefulness. 
This was reported in the discussion thread [1] originating from a bug
report [2].

This is a product of both using the struct address_space->i_mmap_writable
atomic counter to determine whether writing may be permitted, and the
kernel adjusting this counter when any VM_SHARED mapping is performed and
more generally implicitly assuming VM_SHARED implies writable.

It seems sensible that we should only update this mapping if VM_MAYWRITE
is specified, i.e.  whether it is possible that this mapping could at any
point be written to.

If we do so then all we need to do to permit write seals to function as
documented is to clear VM_MAYWRITE when mapping read-only.  It turns out
this functionality already exists for F_SEAL_FUTURE_WRITE - we can
therefore simply adapt this logic to do the same for F_SEAL_WRITE.

We then hit a chicken and egg situation in mmap_region() where the check
for VM_MAYWRITE occurs before we are able to clear this flag.  To work
around this, perform this check after we invoke call_mmap(), with careful
consideration of error paths.

Thanks to Andy Lutomirski for the suggestion!

[1]:https://lore.kernel.org/all/20230324133646.16101dfa666f253c4715d965@linux-foundation.org/
[2]:https://bugzilla.kernel.org/show_bug.cgi?id=217238


This patch (of 3):

There is a general assumption that VMAs with the VM_SHARED flag set are
writable.  If the VM_MAYWRITE flag is not set, then this is simply not the
case.

Update those checks which affect the struct address_space->i_mmap_writable
field to explicitly test for this by introducing
[vma_]is_shared_maywrite() helper functions.

This remains entirely conservative, as the lack of VM_MAYWRITE guarantees
that the VMA cannot be written to.

Link: https://lkml.kernel.org/r/cover.1697116581.git.lstoakes@gmail.com
Link: https://lkml.kernel.org/r/d978aefefa83ec42d18dfa964ad180dbcde34795.1697116581.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:19 -07:00
Matthew Wilcox (Oracle)
b0b598ee08 filemap: remove use of wait bookmarks
The original problem of the overly long list of waiters on a locked page
was solved properly by commit 9a1ea439b1 ("mm:
put_and_wait_on_page_locked() while page is migrated").  In the meantime,
using bookmarks for the writeback bit can cause livelocks, so we need to
stop using them.

Link: https://lkml.kernel.org/r/20231010035829.544242-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Bin Lai <sclaibin@gmail.com>
Cc: Benjamin Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>

Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:18 -07:00
Nhat Pham
85ce2c517a memcontrol: only transfer the memcg data for migration
For most migration use cases, only transfer the memcg data from the old
folio to the new folio, and clear the old folio's memcg data.  No charging
and uncharging will be done.

This shaves off some work on the migration path, and avoids the temporary
double charging of a folio during its migration.

The only exception is replace_page_cache_folio(), which will use the old
mem_cgroup_migrate() (now renamed to mem_cgroup_replace_folio).  In that
context, the isolation of the old page isn't quite as thorough as with
migration, so we cannot use our new implementation directly.

This patch is the result of the following discussion on the new hugetlb
memcg accounting behavior:

https://lore.kernel.org/lkml/20231003171329.GB314430@monkey/

Link: https://lkml.kernel.org/r/20231006184629.155543-3-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>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
2580d55458 mm: use folio_xor_flags_has_waiters() in folio_end_writeback()
Match how folio_unlock() works by combining the test for PG_waiters with
the clearing of PG_writeback.  This should have a small performance win,
and removes the last user of folio_wake().

Link: https://lkml.kernel.org/r/20231004165317.1061855-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
7d0795d098 mm: make __end_folio_writeback() return void
Rather than check the result of test-and-clear, just check that we have
the writeback bit set at the start.  This wouldn't catch every case, but
it's good enough (and enables the next patch).

Link: https://lkml.kernel.org/r/20231004165317.1061855-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
0410cd844e mm: add folio_xor_flags_has_waiters()
Optimise folio_end_read() by setting the uptodate bit at the same time we
clear the unlock bit.  This saves at least one memory barrier and one
write-after-write hazard.

Link: https://lkml.kernel.org/r/20231004165317.1061855-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
f12fb73b74 mm: delete checks for xor_unlock_is_negative_byte()
Architectures which don't define their own use the one in
asm-generic/bitops/lock.h.  Get rid of all the ifdefs around "maybe we
don't have it".

Link: https://lkml.kernel.org/r/20231004165317.1061855-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Matthew Wilcox (Oracle)
247dbcdbf7 bitops: add xor_unlock_is_negative_byte()
Replace clear_bit_and_unlock_is_negative_byte() with
xor_unlock_is_negative_byte().  We have a few places that like to lock a
folio, set a flag and unlock it again.  Allow for the possibility of
combining the latter two operations for efficiency.  We are guaranteed
that the caller holds the lock, so it is safe to unlock it with the xor. 
The caller must guarantee that nobody else will set the flag without
holding the lock; it is not safe to do this with the PG_dirty flag, for
example.

Link: https://lkml.kernel.org/r/20231004165317.1061855-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Matthew Wilcox (Oracle)
0b237047d5 mm: add folio_end_read()
Provide a function for filesystems to call when they have finished reading
an entire folio.

Link: https://lkml.kernel.org/r/20231004165317.1061855-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Pankaj Raghav
bafd7e9d35 filemap: call filemap_get_folios_tag() from filemap_get_folios()
filemap_get_folios() is filemap_get_folios_tag() with XA_PRESENT as the
tag that is being matched.  Return filemap_get_folios_tag() with
XA_PRESENT as the tag instead of duplicating the code in
filemap_get_folios().

No functional changes.

Link: https://lkml.kernel.org/r/20231006110120.136809-1-kernel@pankajraghav.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:16 -07:00
Matthew Wilcox (Oracle)
5d74b2ab2c mm: make lock_folio_maybe_drop_mmap() VMA lock aware
Patch series "Handle more faults under the VMA lock", v2.

At this point, we're handling the majority of file-backed page faults
under the VMA lock, using the ->map_pages entry point.  This patch set
attempts to expand that for the following siutations:

 - We have to do a read.  This could be because we've hit the point in
   the readahead window where we need to kick off the next readahead,
   or because the page is simply not present in cache.
 - We're handling a write fault.  Most applications don't do I/O by writes
   to shared mmaps for very good reasons, but some do, and it'd be nice
   to not make that slow unnecessarily.
 - We're doing a COW of a private mapping (both PTE already present
   and PTE not-present).  These are two different codepaths and I handle
   both of them in this patch set.

There is no support in this patch set for drivers to mark themselves as
being VMA lock friendly; they could implement the ->map_pages
vm_operation, but if they do, they would be the first.  This is probably
something we want to change at some point in the future, and I've marked
where to make that change in the code.

There is very little performance change in the benchmarks we've run;
mostly because the vast majority of page faults are handled through the
other paths.  I still think this patch series is useful for workloads that
may take these paths more often, and just for cleaning up the fault path
in general (it's now clearer why we have to retry in these cases).


This patch (of 6):

Drop the VMA lock instead of the mmap_lock if that's the one which
is held.

Link: https://lkml.kernel.org/r/20231006195318.4087158-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231006195318.4087158-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:14 -07:00
Lorenzo Stoakes
6facf36ee4 mm/filemap: clarify filemap_fault() comments for not uptodate case
The existing comments in filemap_fault() suggest that, after either a
minor fault has occurred and filemap_get_folio() found a folio in the page
cache, or a major fault arose and __filemap_get_folio(FGP_CREATE...) did
the job (having relied on do_sync_mmap_readahead() or filemap_read_folio()
to read in the folio), the only possible reason it could not be uptodate
is because of an error.

This is not so, as if, for instance, the fault occurred within a VMA which
had the VM_RAND_READ flag set (via madvise() with the MADV_RANDOM flag
specified), this would cause even synchronous readahead to fail to read in
the folio.

I confirmed this by dropping page caches and faulting in memory
madvise()'d this way, observing that this code path was reached on each
occasion.

Clarify the comments to include this case, and additionally update the
comment recently added around the invalidate lock logic to make it clear
the comment explicitly refers to the minor fault case.

In addition, while we're here, refer to folios rather than pages.

[lstoakes@gmail.com: correct identation as per Christopher's feedback]
  Link: https://lkml.kernel.org/r/2c7014c0-6343-4e76-8697-3f84f54350bd@lucifer.local
Link: https://lkml.kernel.org/r/20230930231029.88196-1-lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:13 -07:00
Sidhartha Kumar
a08c7193e4 mm/filemap: remove hugetlb special casing in filemap.c
Remove special cased hugetlb handling code within the page cache by
changing the granularity of ->index to the base page size rather than the
huge page size.  The motivation of this patch is to reduce complexity
within the filemap code while also increasing performance by removing
branches that are evaluated on every page cache lookup.

To support the change in index, new wrappers for hugetlb page cache
interactions are added.  These wrappers perform the conversion to a linear
index which is now expected by the page cache for huge pages.

========================= PERFORMANCE ======================================

Perf was used to check the performance differences after the patch. 
Overall the performance is similar to mainline with a very small larger
overhead that occurs in __filemap_add_folio() and
hugetlb_add_to_page_cache().  This is because of the larger overhead that
occurs in xa_load() and xa_store() as the xarray is now using more entries
to store hugetlb folios in the page cache.

Timing

aarch64
    2MB Page Size
        6.5-rc3 + this patch:
            [root@sidhakum-ol9-1 hugepages]# time fallocate -l 700GB test.txt
            real    1m49.568s
            user    0m0.000s
            sys     1m49.461s

        6.5-rc3:
            [root]# time fallocate -l 700GB test.txt
            real    1m47.495s
            user    0m0.000s
            sys     1m47.370s
    1GB Page Size
        6.5-rc3 + this patch:
            [root@sidhakum-ol9-1 hugepages1G]# time fallocate -l 700GB test.txt
            real    1m47.024s
            user    0m0.000s
            sys     1m46.921s

        6.5-rc3:
            [root@sidhakum-ol9-1 hugepages1G]# time fallocate -l 700GB test.txt
            real    1m44.551s
            user    0m0.000s
            sys     1m44.438s

x86
    2MB Page Size
        6.5-rc3 + this patch:
            [root@sidhakum-ol9-2 hugepages]# time fallocate -l 100GB test.txt
            real    0m22.383s
            user    0m0.000s
            sys     0m22.255s

        6.5-rc3:
            [opc@sidhakum-ol9-2 hugepages]$ time sudo fallocate -l 100GB /dev/hugepages/test.txt
            real    0m22.735s
            user    0m0.038s
            sys     0m22.567s

    1GB Page Size
        6.5-rc3 + this patch:
            [root@sidhakum-ol9-2 hugepages1GB]# time fallocate -l 100GB test.txt
            real    0m25.786s
            user    0m0.001s
            sys     0m25.589s

        6.5-rc3:
            [root@sidhakum-ol9-2 hugepages1G]# time fallocate -l 100GB test.txt
            real    0m33.454s
            user    0m0.001s
            sys     0m33.193s

aarch64:
    workload - fallocate a 700GB file backed by huge pages

    6.5-rc3 + this patch:
        2MB Page Size:
            --100.00%--__arm64_sys_fallocate
                          ksys_fallocate
                          vfs_fallocate
                          hugetlbfs_fallocate
                          |
                          |--95.04%--__pi_clear_page
                          |
                          |--3.57%--clear_huge_page
                          |          |
                          |          |--2.63%--rcu_all_qs
                          |          |
                          |           --0.91%--__cond_resched
                          |
                           --0.67%--__cond_resched
            0.17%     0.00%             0  fallocate  [kernel.vmlinux]       [k] hugetlb_add_to_page_cache
            0.14%     0.10%            11  fallocate  [kernel.vmlinux]       [k] __filemap_add_folio

    6.5-rc3
        2MB Page Size:
                --100.00%--__arm64_sys_fallocate
                          ksys_fallocate
                          vfs_fallocate
                          hugetlbfs_fallocate
                          |
                          |--94.91%--__pi_clear_page
                          |
                          |--4.11%--clear_huge_page
                          |          |
                          |          |--3.00%--rcu_all_qs
                          |          |
                          |           --1.10%--__cond_resched
                          |
                           --0.59%--__cond_resched
            0.08%     0.01%             1  fallocate  [kernel.kallsyms]  [k] hugetlb_add_to_page_cache
            0.05%     0.03%             3  fallocate  [kernel.kallsyms]  [k] __filemap_add_folio

x86
    workload - fallocate a 100GB file backed by huge pages

    6.5-rc3 + this patch:
        2MB Page Size:
            hugetlbfs_fallocate
            |
            --99.57%--clear_huge_page
                |
                --98.47%--clear_page_erms
                    |
                    --0.53%--asm_sysvec_apic_timer_interrupt

            0.04%     0.04%             1  fallocate  [kernel.kallsyms]     [k] xa_load
            0.04%     0.00%             0  fallocate  [kernel.kallsyms]     [k] hugetlb_add_to_page_cache
            0.04%     0.00%             0  fallocate  [kernel.kallsyms]     [k] __filemap_add_folio
            0.04%     0.00%             0  fallocate  [kernel.kallsyms]     [k] xas_store

    6.5-rc3
        2MB Page Size:
                --99.93%--__x64_sys_fallocate
                          vfs_fallocate
                          hugetlbfs_fallocate
                          |
                           --99.38%--clear_huge_page
                                     |
                                     |--98.40%--clear_page_erms
                                     |
                                      --0.59%--__cond_resched
            0.03%     0.03%             1  fallocate  [kernel.kallsyms]  [k] __filemap_add_folio

========================= TESTING ======================================

This patch passes libhugetlbfs tests and LTP hugetlb tests

********** TEST SUMMARY
*                      2M
*                      32-bit 64-bit
*     Total testcases:   110    113
*             Skipped:     0      0
*                PASS:   107    113
*                FAIL:     0      0
*    Killed by signal:     3      0
*   Bad configuration:     0      0
*       Expected FAIL:     0      0
*     Unexpected PASS:     0      0
*    Test not present:     0      0
* Strange test result:     0      0
**********

    Done executing testcases.
    LTP Version:  20220527-178-g2761a81c4

page migration was also tested using Mike Kravetz's test program.[8]

[dan.carpenter@linaro.org: fix an NULL vs IS_ERR() bug]
  Link: https://lkml.kernel.org/r/1772c296-1417-486f-8eef-171af2192681@moroto.mountain
Link: https://lkml.kernel.org/r/20230926192017.98183-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reported-and-tested-by: syzbot+c225dea486da4d5592bd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c225dea486da4d5592bd
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-16 15:44:38 -07:00
Minjie Du
d98388cef5 mm/filemap: increase usage of folio_next_index() helper
Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index() in filemap_map_pages().

Link: https://lkml.kernel.org/r/20230921081535.3398-1-duminjie@vivo.com
Signed-off-by: Minjie Du <duminjie@vivo.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-06 14:44:11 -07:00
Matthew Wilcox (Oracle)
a501a07030 mm: report success more often from filemap_map_folio_range()
Even though we had successfully mapped the relevant page, we would rarely
return success from filemap_map_folio_range().  That leads to falling back
from the VMA lock path to the mmap_lock path, which is a speed &
scalability issue.  Found by inspection.

Link: https://lkml.kernel.org/r/20230920035336.854212-1-willy@infradead.org
Fixes: 617c28ecab ("filemap: batch PTE mappings")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-29 17:20:45 -07:00
Yin Fengwei
c8be038067 filemap: add filemap_map_order0_folio() to handle order0 folio
Kernel test robot reported regressions for several benchmarks [1].
The regression are related with commit:
de74976eb6 ("filemap: add filemap_map_folio_range()")

It turned out that function filemap_map_folio_range() brings these
regressions when handle folio with order0.

Add filemap_map_order0_folio() to handle order0 folio. The benefit
come from two perspectives:
  - the code size is smaller (around 126 bytes)
  - no loop

Testing showed the regressions reported by 0day [1] all are fixed:
commit 9f1f5b60e7: parent commit of de74976eb6
commit fbdf9263a3d7fdbd: latest mm-unstable commit
commit 7fbfe2003f84686d: this fixing patch

9f1f5b60e7 fbdf9263a3d7fdbd            7fbfe2003f84686d
---------------- --------------------------- ---------------------------
   3843810           -21.4%    3020268            +4.6%    4018708      stress-ng.bad-altstack.ops
     64061           -21.4%      50336            +4.6%      66977      stress-ng.bad-altstack.ops_per_sec

   1709026           -14.4%    1462102            +2.4%    1750757      stress-ng.fork.ops
     28483           -14.4%      24368            +2.4%      29179      stress-ng.fork.ops_per_sec

   3685088           -53.6%    1710976            +0.5%    3702454      stress-ng.zombie.ops
     56732           -65.3%      19667            +0.7%      57107      stress-ng.zombie.ops_per_sec

     61874           -12.1%      54416            +0.4%      62136      vm-scalability.median
  13527663           -11.7%   11942117            -0.1%   13513946      vm-scalability.throughput
 4.066e+09           -11.7%   3.59e+09            -0.1%  4.061e+09      vm-scalability.workload

[1]:
https://lore.kernel.org/oe-lkp/72e017b9-deb6-44fa-91d6-716ee2c39cbc@intel.com/T/#m7d2bba30f75a9cee8eab07e5809abd9b3b206c84

Link: https://lkml.kernel.org/r/20230914134741.1937654-1-fengwei.yin@intel.com
Fixes: de74976eb6 ("filemap: add filemap_map_folio_range()")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202309111556.b2aa3d7a-oliver.sang@intel.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:34 -07:00
Tong Tiangen
d256d1cd8d mm: memory-failure: use rcu lock instead of tasklist_lock when collect_procs()
We found a softlock issue in our test, analyzed the logs, and found that
the relevant CPU call trace as follows:

CPU0:
  _do_fork
    -> copy_process()
      -> write_lock_irq(&tasklist_lock)  //Disable irq,waiting for
      					 //tasklist_lock

CPU1:
  wp_page_copy()
    ->pte_offset_map_lock()
      -> spin_lock(&page->ptl);        //Hold page->ptl
    -> ptep_clear_flush()
      -> flush_tlb_others() ...
        -> smp_call_function_many()
          -> arch_send_call_function_ipi_mask()
            -> csd_lock_wait()         //Waiting for other CPUs respond
	                               //IPI

CPU2:
  collect_procs_anon()
    -> read_lock(&tasklist_lock)       //Hold tasklist_lock
      ->for_each_process(tsk)
        -> page_mapped_in_vma()
          -> page_vma_mapped_walk()
	    -> map_pte()
              ->spin_lock(&page->ptl)  //Waiting for page->ptl

We can see that CPU1 waiting for CPU0 respond IPI,CPU0 waiting for CPU2
unlock tasklist_lock, CPU2 waiting for CPU1 unlock page->ptl. As a result,
softlockup is triggered.

For collect_procs_anon(), what we're doing is task list iteration, during
the iteration, with the help of call_rcu(), the task_struct object is freed
only after one or more grace periods elapse. the logic as follows:

release_task()
  -> __exit_signal()
    -> __unhash_process()
      -> list_del_rcu()

  -> put_task_struct_rcu_user()
    -> call_rcu(&task->rcu, delayed_put_task_struct)

delayed_put_task_struct()
  -> put_task_struct()
  -> if (refcount_sub_and_test())
     	__put_task_struct()
          -> free_task()

Therefore, under the protection of the rcu lock, we can safely use
get_task_struct() to ensure a safe reference to task_struct during the
iteration.

By removing the use of tasklist_lock in task list iteration, we can break
the softlock chain above.

The same logic can also be applied to:
 - collect_procs_file()
 - collect_procs_fsdax()
 - collect_procs_ksm()

Link: https://lkml.kernel.org/r/20230828022527.241693-1-tongtiangen@huawei.com
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-05 11:11:52 -07:00
Linus Torvalds
b96a3e9142 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP.  It
   also speeds up GUP handling of transparent hugepages.
 
 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").
 
 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").
 
 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").
 
 - xu xin has doe some work on KSM's handling of zero pages.  These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support tracking
   KSM-placed zero-pages").
 
 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
 
 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").
 
 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD").
 
 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").
 
 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").
 
 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").
 
 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").
 
 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").
 
 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap").  And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").
 
 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
 
 - Baoquan He has converted some architectures to use the GENERIC_IOREMAP
   ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take
   GENERIC_IOREMAP way").
 
 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").
 
 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep").  Liam also developed some efficiency improvements
   ("Reduce preallocations for maple tree").
 
 - Cleanup and optimization to the secondary IOMMU TLB invalidation, from
   Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").
 
 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").
 
 - Kemeng Shi provides some maintenance work on the compaction code ("Two
   minor cleanups for compaction").
 
 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most
   file-backed faults under the VMA lock").
 
 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").
 
 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").
 
 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").
 
 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
 
 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").
 
 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").
 
 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
 
 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").
 
 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").
 
 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap
   on memory feature on ppc64").
 
 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock migratetype").
 
 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").
 
 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").
 
 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").
 
 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").
 
 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").
 
 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").
 
 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").
 
 - pagetable handling cleanups from Matthew Wilcox ("New page table range
   API").
 
 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").
 
 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").
 
 - Matthew Wilcox has also done some maintenance work on the MM subsystem
   documentation ("Improve mm documentation").
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Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...
2023-08-29 14:25:26 -07:00
Yin Fengwei
617c28ecab filemap: batch PTE mappings
Call set_pte_range() once per contiguous range of the folio instead of
once per page.  This batches the updates to mm counters and the rmap.

With a will-it-scale.page_fault3 like app (change file write fault testing
to read fault testing.  Trying to upstream it to will-it-scale at [1]) got
15% performance gain on a 48C/96T Cascade Lake test box with 96 processes
running against xfs.

Perf data collected before/after the change:
  18.73%--page_add_file_rmap
          |
           --11.60%--__mod_lruvec_page_state
                     |
                     |--7.40%--__mod_memcg_lruvec_state
                     |          |
                     |           --5.58%--cgroup_rstat_updated
                     |
                      --2.53%--__mod_lruvec_state
                                |
                                 --1.48%--__mod_node_page_state

  9.93%--page_add_file_rmap_range
         |
          --2.67%--__mod_lruvec_page_state
                    |
                    |--1.95%--__mod_memcg_lruvec_state
                    |          |
                    |           --1.57%--cgroup_rstat_updated
                    |
                     --0.61%--__mod_lruvec_state
                               |
                                --0.54%--__mod_node_page_state

The running time of __mode_lruvec_page_state() is reduced about 9%.

[1]: https://github.com/antonblanchard/will-it-scale/pull/37

Link: https://lkml.kernel.org/r/20230802151406.3735276-38-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:26 -07:00
Yin Fengwei
3bd786f76d mm: convert do_set_pte() to set_pte_range()
set_pte_range() allows to setup page table entries for a specific
range.  It takes advantage of batched rmap update for large folio.
It now takes care of calling update_mmu_cache_range().

Link: https://lkml.kernel.org/r/20230802151406.3735276-37-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:26 -07:00
Yin Fengwei
de74976eb6 filemap: add filemap_map_folio_range()
filemap_map_folio_range() maps partial/full folio.  Comparing to original
filemap_map_pages(), it updates refcount once per folio instead of per
page and gets minor performance improvement for large folio.

With a will-it-scale.page_fault3 like app (change file write fault testing
to read fault testing.  Trying to upstream it to will-it-scale at [1]),
got 2% performance gain on a 48C/96T Cascade Lake test box with 96
processes running against xfs.

[1]: https://github.com/antonblanchard/will-it-scale/pull/37

Link: https://lkml.kernel.org/r/20230802151406.3735276-35-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:26 -07:00
Suren Baghdasaryan
1235ccd05b mm: handle swap page faults under per-VMA lock
When page fault is handled under per-VMA lock protection, all swap page
faults are retried with mmap_lock because folio_lock_or_retry has to drop
and reacquire mmap_lock if folio could not be immediately locked.  Follow
the same pattern as mmap_lock to drop per-VMA lock when waiting for folio
and retrying once folio is available.

With this obstacle removed, enable do_swap_page to operate under per-VMA
lock protection.  Drivers implementing ops->migrate_to_ram might still
rely on mmap_lock, therefore we have to fall back to mmap_lock in that
particular case.

Note that the only time do_swap_page calls synchronous swap_readpage is
when SWP_SYNCHRONOUS_IO is set, which is only set for
QUEUE_FLAG_SYNCHRONOUS devices: brd, zram and nvdimms (both btt and pmem).
Therefore we don't sleep in this path, and there's no need to drop the
mmap or per-VMA lock.

Link: https://lkml.kernel.org/r/20230630211957.1341547-6-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:17 -07:00
Suren Baghdasaryan
fdc724d6aa mm: change folio_lock_or_retry to use vm_fault directly
Change folio_lock_or_retry to accept vm_fault struct and return the
vm_fault_t directly.

Link: https://lkml.kernel.org/r/20230630211957.1341547-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:20:17 -07:00
David Howells
0201ebf274 mm: merge folio_has_private()/filemap_release_folio() call pairs
Patch series "mm, netfs, fscache: Stop read optimisation when folio
removed from pagecache", v7.

This fixes an optimisation in fscache whereby we don't read from the cache
for a particular file until we know that there's data there that we don't
have in the pagecache.  The problem is that I'm no longer using PG_fscache
(aka PG_private_2) to indicate that the page is cached and so I don't get
a notification when a cached page is dropped from the pagecache.

The first patch merges some folio_has_private() and
filemap_release_folio() pairs and introduces a helper,
folio_needs_release(), to indicate if a release is required.

The second patch is the actual fix.  Following Willy's suggestions[1], it
adds an AS_RELEASE_ALWAYS flag to an address_space that will make
filemap_release_folio() always call ->release_folio(), even if
PG_private/PG_private_2 aren't set.  folio_needs_release() is altered to
add a check for this.


This patch (of 2):

Make filemap_release_folio() check folio_has_private().  Then, in most
cases, where a call to folio_has_private() is immediately followed by a
call to filemap_release_folio(), we can get rid of the test in the pair.

There are a couple of sites in mm/vscan.c that this can't so easily be
done.  In shrink_folio_list(), there are actually three cases (something
different is done for incompletely invalidated buffers), but
filemap_release_folio() elides two of them.

In shrink_active_list(), we don't have have the folio lock yet, so the
check allows us to avoid locking the page unnecessarily.

A wrapper function to check if a folio needs release is provided for those
places that still need to do it in the mm/ directory.  This will acquire
additional parts to the condition in a future patch.

After this, the only remaining caller of folio_has_private() outside of
mm/ is a check in fuse.

Link: https://lkml.kernel.org/r/20230628104852.3391651-1-dhowells@redhat.com
Link: https://lkml.kernel.org/r/20230628104852.3391651-2-dhowells@redhat.com
Reported-by: Rohith Surabattula <rohiths.msft@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steve French <sfrench@samba.org>
Cc: Shyam Prasad N <nspmangalore@gmail.com>
Cc: Rohith Surabattula <rohiths.msft@gmail.com>
Cc: Dave Wysochanski <dwysocha@redhat.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:12 -07:00
Haibo Li
f04d16ee3a mm/filemap.c: fix update prev_pos after one read request done
ra->prev_pos tracks the last visited byte in the previous read request. 
It is used to check whether it is sequential read in ondemand_readahead
and thus affects the readahead window.

After commit 06c0444290 ("mm/filemap.c: generic_file_buffered_read() now
uses find_get_pages_contig"), update logic of prev_pos is changed.  It
updates prev_pos after each return from filemap_get_pages().  But the read
request from user may be not fully completed at this point.  The updated
prev_pos impacts the subsequent readahead window.

The real problem is performance drop of fsck_msdos between linux-5.4 and
linux-5.15(also linux-6.4).  Comparing to linux-5.4,It spends about 110%
time and read 140% pages.  The read pattern of fsck_msdos is not fully
sequential.

Simplified read pattern of fsck_msdos likes below:
1.read at page offset 0xa,size 0x1000
2.read at other page offset like 0x20,size 0x1000
3.read at page offset 0xa,size 0x4000
4.read at page offset 0xe,size 0x1000

Here is the read status on linux-6.4:
1.after read at page offset 0xa,size 0x1000
    ->page ofs 0xa go into pagecache
2.after read at page offset 0x20,size 0x1000
    ->page ofs 0x20 go into pagecache
3.read at page offset 0xa,size 0x4000
    ->filemap_get_pages read ofs 0xa from pagecache and returns
    ->prev_pos is updated to 0xb and goto next loop
    ->filemap_get_pages tends to read ofs 0xb,size 0x3000
    ->initial_readahead case in ondemand_readahead since prev_pos is
      the same as request ofs.
    ->read 8 pages while async size is 5 pages
      (PageReadahead flag at page 0xe)
4.read at page offset 0xe,size 0x1000
    ->hit page 0xe with PageReadahead flag set,double the ra_size.
      read 16 pages while async size is 16 pages
Now it reads 24 pages while actually uses 5 pages

on linux-5.4:
1.the same as 6.4
2.the same as 6.4
3.read at page offset 0xa,size 0x4000
    ->read ofs 0xa from pagecache
    ->read ofs 0xb,size 0x3000 using page_cache_sync_readahead
      read 3 pages
    ->prev_pos is updated to 0xd before generic_file_buffered_read
      returns
4.read at page offset 0xe,size 0x1000
    ->initial_readahead case in ondemand_readahead since
      request ofs-prev_pos==1
    ->read 4 pages while async size is 3 pages

Now it reads 7 pages while actually uses 5 pages.

In above demo, the initial_readahead case is triggered by offset of user
request on linux-5.4.  While it may be triggered by update logic of
prev_pos on linux-6.4.

To fix the performance drop, update prev_pos after finishing one read
request.

Link: https://lkml.kernel.org/r/20230628110220.120134-1-haibo.li@mediatek.com
Signed-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:04 -07:00
Sidhartha Kumar
87b11f8622 mm: increase usage of folio_next_index() helper
Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index().

Link: https://lkml.kernel.org/r/20230627174349.491803-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:00 -07:00
Matthew Wilcox (Oracle)
4f66170119 filemap: Allow __filemap_get_folio to allocate large folios
Allow callers of __filemap_get_folio() to specify a preferred folio
order in the FGP flags.  This is only honoured in the FGP_CREATE path;
if there is already a folio in the page cache that covers the index,
we will return it, no matter what its order is.  No create-around is
attempted; we will only create folios which start at the specified index.
Unmodified callers will continue to allocate order 0 folios.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-07-24 18:04:30 -04:00
Matthew Wilcox (Oracle)
ffc143db63 filemap: Add fgf_t typedef
Similarly to gfp_t, define fgf_t as its own type to prevent various
misuses and confusion.  Leave the flags as FGP_* for now to reduce the
size of this patch; they will be converted to FGF_* later.  Move the
documentation to the definition of the type insted of burying it in the
__filemap_get_folio() documentation.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-07-24 18:04:30 -04:00
Linus Torvalds
6e17c6de3d - Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing.
 
 - Nhat Pham adds the new cachestat() syscall.  It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability.
 
 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning.
 
 - Lorenzo Stoakes has done some maintanance work on the get_user_pages()
   interface.
 
 - Liam Howlett continues with cleanups and maintenance work to the maple
   tree code.  Peng Zhang also does some work on maple tree.
 
 - Johannes Weiner has done some cleanup work on the compaction code.
 
 - David Hildenbrand has contributed additional selftests for
   get_user_pages().
 
 - Thomas Gleixner has contributed some maintenance and optimization work
   for the vmalloc code.
 
 - Baolin Wang has provided some compaction cleanups,
 
 - SeongJae Park continues maintenance work on the DAMON code.
 
 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting.
 
 - Christoph Hellwig has some cleanups for the filemap/directio code.
 
 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the provided
   APIs rather than open-coding accesses.
 
 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings.
 
 - John Hubbard has a series of fixes to the MM selftesting code.
 
 - ZhangPeng continues the folio conversion campaign.
 
 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock.
 
 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
   128 to 8.
 
 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management.
 
 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code.
 
 - Vishal Moola also has done some folio conversion work.
 
 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
Linus Torvalds
3eccc0c886 for-6.5/splice-2023-06-23
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Merge tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux

Pull splice updates from Jens Axboe:
 "This kills off ITER_PIPE to avoid a race between truncate,
  iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio
  with unpinned/unref'ed pages from an O_DIRECT splice read. This causes
  memory corruption.

  Instead, we either use (a) filemap_splice_read(), which invokes the
  buffered file reading code and splices from the pagecache into the
  pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads
  into it and then pushes the filled pages into the pipe; or (c) handle
  it in filesystem-specific code.

  Summary:

   - Rename direct_splice_read() to copy_splice_read()

   - Simplify the calculations for the number of pages to be reclaimed
     in copy_splice_read()

   - Turn do_splice_to() into a helper, vfs_splice_read(), so that it
     can be used by overlayfs and coda to perform the checks on the
     lower fs

   - Make vfs_splice_read() jump to copy_splice_read() to handle
     direct-I/O and DAX

   - Provide shmem with its own splice_read to handle non-existent pages
     in the pagecache. We don't want a ->read_folio() as we don't want
     to populate holes, but filemap_get_pages() requires it

   - Provide overlayfs with its own splice_read to call down to a lower
     layer as overlayfs doesn't provide ->read_folio()

   - Provide coda with its own splice_read to call down to a lower layer
     as coda doesn't provide ->read_folio()

   - Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
     and random files as they just copy to the output buffer and don't
     splice pages

   - Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
     ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation

   - Make cifs use filemap_splice_read()

   - Replace pointers to generic_file_splice_read() with pointers to
     filemap_splice_read() as DIO and DAX are handled in the caller;
     filesystems can still provide their own alternate ->splice_read()
     op

   - Remove generic_file_splice_read()

   - Remove ITER_PIPE and its paraphernalia as generic_file_splice_read
     was the only user"

* tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits)
  splice: kdoc for filemap_splice_read() and copy_splice_read()
  iov_iter: Kill ITER_PIPE
  splice: Remove generic_file_splice_read()
  splice: Use filemap_splice_read() instead of generic_file_splice_read()
  cifs: Use filemap_splice_read()
  trace: Convert trace/seq to use copy_splice_read()
  zonefs: Provide a splice-read wrapper
  xfs: Provide a splice-read wrapper
  orangefs: Provide a splice-read wrapper
  ocfs2: Provide a splice-read wrapper
  ntfs3: Provide a splice-read wrapper
  nfs: Provide a splice-read wrapper
  f2fs: Provide a splice-read wrapper
  ext4: Provide a splice-read wrapper
  ecryptfs: Provide a splice-read wrapper
  ceph: Provide a splice-read wrapper
  afs: Provide a splice-read wrapper
  9p: Add splice_read wrapper
  net: Make sock_splice_read() use copy_splice_read() by default
  tty, proc, kernfs, random: Use copy_splice_read()
  ...
2023-06-26 11:52:12 -07:00
Mike Kravetz
16f8eb3eea Revert "page cache: fix page_cache_next/prev_miss off by one"
This reverts commit 9425c591e0

The reverted commit fixed up routines primarily used by readahead code
such that they could also be used by hugetlb.  Unfortunately, this
caused a performance regression as pointed out by the Closes: tag.

The hugetlb code which uses page_cache_next_miss will be addressed in
a subsequent patch.

Link: https://lkml.kernel.org/r/20230621212403.174710-1-mike.kravetz@oracle.com
Fixes: 9425c591e0 ("page cache: fix page_cache_next/prev_miss off by one")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202306211346.1e9ff03e-oliver.sang@intel.com
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23 16:59:32 -07:00
Andrew Morton
63773d2b59 Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
Kefeng Wang
6c77b607ee mm: kill lock|unlock_page_memcg()
Since commit c7c3dec1c9 ("mm: rmap: remove lock_page_memcg()"),
no more user, kill lock_page_memcg() and unlock_page_memcg().

Link: https://lkml.kernel.org/r/20230614143612.62575-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:33 -07:00
Ryan Roberts
c33c794828 mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use
ptep_get() helper.  This means that by default, the accesses change from a
C dereference to a READ_ONCE().  This is technically the correct thing to
do since where pgtables are modified by HW (for access/dirty) they are
volatile and therefore we should always ensure READ_ONCE() semantics.

But more importantly, by always using the helper, it can be overridden by
the architecture to fully encapsulate the contents of the pte.  Arch code
is deliberately not converted, as the arch code knows best.  It is
intended that arch code (arm64) will override the default with its own
implementation that can (e.g.) hide certain bits from the core code, or
determine young/dirty status by mixing in state from another source.

Conversion was done using Coccinelle:

----

// $ make coccicheck \
//          COCCI=ptepget.cocci \
//          SPFLAGS="--include-headers" \
//          MODE=patch

virtual patch

@ depends on patch @
pte_t *v;
@@

- *v
+ ptep_get(v)

----

Then reviewed and hand-edited to avoid multiple unnecessary calls to
ptep_get(), instead opting to store the result of a single call in a
variable, where it is correct to do so.  This aims to negate any cost of
READ_ONCE() and will benefit arch-overrides that may be more complex.

Included is a fix for an issue in an earlier version of this patch that
was pointed out by kernel test robot.  The issue arose because config
MMU=n elides definition of the ptep helper functions, including
ptep_get().  HUGETLB_PAGE=n configs still define a simple
huge_ptep_clear_flush() for linking purposes, which dereferences the ptep.
So when both configs are disabled, this caused a build error because
ptep_get() is not defined.  Fix by continuing to do a direct dereference
when MMU=n.  This is safe because for this config the arch code cannot be
trying to virtualize the ptes because none of the ptep helpers are
defined.

Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:25 -07:00
Hugh Dickins
65747aaf42 mm/filemap: allow pte_offset_map_lock() to fail
filemap_map_pages() allow pte_offset_map_lock() to fail; and remove the
pmd_devmap_trans_unstable() check from filemap_map_pmd(), which can safely
return to filemap_map_pages() and let pte_offset_map_lock() discover that.

Link: https://lkml.kernel.org/r/54607cf4-ddb6-7ef3-043-1d2de1a9a71@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zack Rusin <zackr@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:13 -07:00
Hugh Dickins
0cb8fd4d14 mm/migrate: remove cruft from migration_entry_wait()s
migration_entry_wait_on_locked() does not need to take a mapped pte
pointer, its callers can do the unmap first.  Annotate it with
__releases(ptl) to reduce sparse warnings.

Fold __migration_entry_wait_huge() into migration_entry_wait_huge().  Fold
__migration_entry_wait() into migration_entry_wait(), preferring the
tighter pte_offset_map_lock() to pte_offset_map() and pte_lockptr().

Link: https://lkml.kernel.org/r/b0e2a532-cdf2-561b-e999-f3b13b8d6d3@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zack Rusin <zackr@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:12 -07:00
Mike Kravetz
9425c591e0 page cache: fix page_cache_next/prev_miss off by one
Ackerley Tng reported an issue with hugetlbfs fallocate here[1].  The
issue showed up after the conversion of hugetlb page cache lookup code to
use page_cache_next_miss.  Code in hugetlb fallocate, userfaultfd and GUP
is now using page_cache_next_miss to determine if a page is present the
page cache.  The following statement is used.

	present = page_cache_next_miss(mapping, index, 1) != index;

There are two issues with page_cache_next_miss when used in this way.
1) If the passed value for index is equal to the 'wrap-around' value,
   the same index will always be returned.  This wrap-around value is 0,
   so 0 will be returned even if page is present at index 0.
2) If there is no gap in the range passed, the last index in the range
   will be returned.  When passed a range of 1 as above, the passed
   index value will be returned even if the page is present.
The end result is the statement above will NEVER indicate a page is
present in the cache, even if it is.

As noted by Ackerley in [1], users can see this by hugetlb fallocate
incorrectly returning EEXIST if pages are already present in the file.  In
addition, hugetlb pages will not be included in core dumps if they need to
be brought in via GUP.  userfaultfd UFFDIO_COPY also uses this code and
will not notice pages already present in the cache.  It may try to
allocate a new page and potentially return ENOMEM as opposed to EEXIST.

Both page_cache_next_miss and page_cache_prev_miss have similar issues.
Fix by:
- Check for index equal to 'wrap-around' value and do not exit early.
- If no gap is found in range, return index outside range.
- Update function description to say 'wrap-around' value could be
  returned if passed as index.

[1] https://lore.kernel.org/linux-mm/cover.1683069252.git.ackerleytng@google.com/

Link: https://lkml.kernel.org/r/20230602225747.103865-2-mike.kravetz@oracle.com
Fixes: d0ce0e47b3 ("mm/hugetlb: convert hugetlb fault paths to use alloc_hugetlb_folio()")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Ackerley Tng <ackerleytng@google.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Tested-by: Ackerley Tng <ackerleytng@google.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-12 11:31:52 -07:00
Christoph Hellwig
44fff0fa08 fs: factor out a direct_write_fallback helper
Add a helper dealing with handling the syncing of a buffered write
fallback for direct I/O.

Link: https://lkml.kernel.org/r/20230601145904.1385409-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:53 -07:00
Christoph Hellwig
c402a9a943 filemap: add a kiocb_invalidate_post_direct_write helper
Add a helper to invalidate page cache after a dio write.

Link: https://lkml.kernel.org/r/20230601145904.1385409-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:53 -07:00
Christoph Hellwig
e003f74afb filemap: add a kiocb_invalidate_pages helper
Factor out a helper that calls filemap_write_and_wait_range and
invalidate_inode_pages2_range for the range covered by a write kiocb or
returns -EAGAIN if the kiocb is marked as nowait and there would be pages
to write or invalidate.

Link: https://lkml.kernel.org/r/20230601145904.1385409-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:52 -07:00
Christoph Hellwig
3c435a0fe3 filemap: add a kiocb_write_and_wait helper
Factor out a helper that does filemap_write_and_wait_range for the range
covered by a read kiocb, or returns -EAGAIN if the kiocb is marked as
nowait and there would be pages to write.

Link: https://lkml.kernel.org/r/20230601145904.1385409-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:52 -07:00
Christoph Hellwig
182c25e9c1 filemap: update ki_pos in generic_perform_write
All callers of generic_perform_write need to updated ki_pos, move it into
common code.

Link: https://lkml.kernel.org/r/20230601145904.1385409-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:52 -07:00
Christoph Hellwig
0d625446d0 backing_dev: remove current->backing_dev_info
Patch series "cleanup the filemap / direct I/O interaction", v4.

This series cleans up some of the generic write helper calling conventions
and the page cache writeback / invalidation for direct I/O.  This is a
spinoff from the no-bufferhead kernel project, for which we'll want to an
use iomap based buffered write path in the block layer.


This patch (of 12):

The last user of current->backing_dev_info disappeared in commit
b9b1335e64 ("remove bdi_congested() and wb_congested() and related
functions").  Remove the field and all assignments to it.

Link: https://lkml.kernel.org/r/20230601145904.1385409-1-hch@lst.de
Link: https://lkml.kernel.org/r/20230601145904.1385409-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:51 -07:00
Pankaj Raghav
c963901197 filemap: remove page_endio()
page_endio() is not used anymore. Remove it.

Link: https://lkml.kernel.org/r/20230510124716.73655-1-p.raghav@samsung.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:18 -07:00
Nhat Pham
cf264e1329 cachestat: implement cachestat syscall
There is currently no good way to query the page cache state of large file
sets and directory trees.  There is mincore(), but it scales poorly: the
kernel writes out a lot of bitmap data that userspace has to aggregate,
when the user really doesn not care about per-page information in that
case.  The user also needs to mmap and unmap each file as it goes along,
which can be quite slow as well.

Some use cases where this information could come in handy:
  * Allowing database to decide whether to perform an index scan or
    direct table queries based on the in-memory cache state of the
    index.
  * Visibility into the writeback algorithm, for performance issues
    diagnostic.
  * Workload-aware writeback pacing: estimating IO fulfilled by page
    cache (and IO to be done) within a range of a file, allowing for
    more frequent syncing when and where there is IO capacity, and
    batching when there is not.
  * Computing memory usage of large files/directory trees, analogous to
    the du tool for disk usage.

More information about these use cases could be found in the following
thread:

https://lore.kernel.org/lkml/20230315170934.GA97793@cmpxchg.org/

This patch implements a new syscall that queries cache state of a file and
summarizes the number of cached pages, number of dirty pages, number of
pages marked for writeback, number of (recently) evicted pages, etc.  in a
given range.  Currently, the syscall is only wired in for x86
architecture.

NAME
    cachestat - query the page cache statistics of a file.

SYNOPSIS
    #include <sys/mman.h>

    struct cachestat_range {
        __u64 off;
        __u64 len;
    };

    struct cachestat {
        __u64 nr_cache;
        __u64 nr_dirty;
        __u64 nr_writeback;
        __u64 nr_evicted;
        __u64 nr_recently_evicted;
    };

    int cachestat(unsigned int fd, struct cachestat_range *cstat_range,
        struct cachestat *cstat, unsigned int flags);

DESCRIPTION
    cachestat() queries the number of cached pages, number of dirty
    pages, number of pages marked for writeback, number of evicted
    pages, number of recently evicted pages, in the bytes range given by
    `off` and `len`.

    An evicted page is a page that is previously in the page cache but
    has been evicted since. A page is recently evicted if its last
    eviction was recent enough that its reentry to the cache would
    indicate that it is actively being used by the system, and that
    there is memory pressure on the system.

    These values are returned in a cachestat struct, whose address is
    given by the `cstat` argument.

    The `off` and `len` arguments must be non-negative integers. If
    `len` > 0, the queried range is [`off`, `off` + `len`]. If `len` ==
    0, we will query in the range from `off` to the end of the file.

    The `flags` argument is unused for now, but is included for future
    extensibility. User should pass 0 (i.e no flag specified).

    Currently, hugetlbfs is not supported.

    Because the status of a page can change after cachestat() checks it
    but before it returns to the application, the returned values may
    contain stale information.

RETURN VALUE
    On success, cachestat returns 0. On error, -1 is returned, and errno
    is set to indicate the error.

ERRORS
    EFAULT cstat or cstat_args points to an invalid address.

    EINVAL invalid flags.

    EBADF  invalid file descriptor.

    EOPNOTSUPP file descriptor is of a hugetlbfs file

[nphamcs@gmail.com: replace rounddown logic with the existing helper]
  Link: https://lkml.kernel.org/r/20230504022044.3675469-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20230503013608.2431726-3-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:16 -07:00
David Howells
9eee8bd814 splice: kdoc for filemap_splice_read() and copy_splice_read()
Provide kerneldoc comments for filemap_splice_read() and
copy_splice_read().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christian Brauner <brauner@kernel.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Jens Axboe <axboe@kernel.dk>
cc: Steve French <smfrench@gmail.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-32-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:17 -06:00
David Howells
3fc40265ae iov_iter: Kill ITER_PIPE
The ITER_PIPE-type iterator was only used by generic_file_splice_read() and
that has been replaced and removed.  This leaves ITER_PIPE unused - so
remove it too.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-31-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:17 -06:00
David Howells
83aeff881e splice: Make filemap_splice_read() check s_maxbytes
Make filemap_splice_read() check s_maxbytes analogously to filemap_read().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Steve French <stfrench@microsoft.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-3-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:15 -06:00
David Howells
c37222082f splice: Fix filemap_splice_read() to use the correct inode
Fix filemap_splice_read() to use file->f_mapping->host, not file->f_inode,
as the source of the file size because in the case of a block device,
file->f_inode points to the block-special file (which is typically 0
length) and not the backing store.

Fixes: 07073eb01c ("splice: Add a func to do a splice from a buffered file without ITER_PIPE")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Steve French <stfrench@microsoft.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-2-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:15 -06:00
Matthew Wilcox
38a55db987 filemap: Handle error return from __filemap_get_folio()
Smatch reports that filemap_fault() was missed in the conversion of
__filemap_get_folio() error returns from NULL to ERR_PTR.

Fixes: 66dabbb65d ("mm: return an ERR_PTR from __filemap_get_folio")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Reported-by: syzbot+48011b86c8ea329af1b9@syzkaller.appspotmail.com
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-06 10:08:59 -07:00
Christoph Hellwig
66dabbb65d mm: return an ERR_PTR from __filemap_get_folio
Instead of returning NULL for all errors, distinguish between:

 - no entry found and not asked to allocated (-ENOENT)
 - failed to allocate memory (-ENOMEM)
 - would block (-EAGAIN)

so that callers don't have to guess the error based on the passed in
flags.

Also pass through the error through the direct callers: filemap_get_folio,
filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio.

[hch@lst.de: fix null-pointer deref]
  Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de
  Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004
Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nilfs2]
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:42 -07:00
Christoph Hellwig
48c9d11375 mm: remove FGP_ENTRY
FGP_ENTRY is unused now, so remove it.

Link: https://lkml.kernel.org/r/20230307143410.28031-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:42 -07:00
Christoph Hellwig
263e721e3b mm: make mapping_get_entry available outside of filemap.c
mapping_get_entry is useful for page cache API users that need to know
about xa_value internals.  Rename it and make it available in pagemap.h.

Link: https://lkml.kernel.org/r/20230307143410.28031-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:41 -07:00
Linus Torvalds
3822a7c409 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X bit.
 
 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.
 
 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes
 
 - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
   does perform some memcg maintenance and cleanup work.
 
 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".  These filters provide users
   with finer-grained control over DAMOS's actions.  SeongJae has also done
   some DAMON cleanup work.
 
 - Kairui Song adds a series ("Clean up and fixes for swap").
 
 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".
 
 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series.  It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.
 
 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".
 
 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".
 
 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".
 
 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".
 
 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series "mm:
   support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
   PTEs".
 
 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".
 
 - Sergey Senozhatsky has improved zsmalloc's memory utilization with his
   series "zsmalloc: make zspage chain size configurable".
 
 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.  The previous BPF-based approach had
   shortcomings.  See "mm: In-kernel support for memory-deny-write-execute
   (MDWE)".
 
 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
 
 - T.J.  Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".
 
 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a per-node
   basis.  See the series "Introduce per NUMA node memory error
   statistics".
 
 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage during
   compaction".
 
 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".
 
 - Christoph Hellwig has removed block_device_operations.rw_page() in ths
   series "remove ->rw_page".
 
 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".
 
 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier functions".
 
 - Some pagemap cleanup and generalization work in Mike Rapoport's series
   "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
   "fixups for generic implementation of pfn_valid()"
 
 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
 
 - Jason Gunthorpe rationalized the GUP system's interface to the rest of
   the kernel in the series "Simplify the external interface for GUP".
 
 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface.  To support this, we'll temporarily be
   printing warnings when people use the debugfs interface.  See the series
   "mm/damon: deprecate DAMON debugfs interface".
 
 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.
 
 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".
 
 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...
2023-02-23 17:09:35 -08:00
David Howells
7c8e01ebf2 splice: Export filemap/direct_splice_read()
filemap_splice_read() and direct_splice_read() should be exported.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20 17:25:43 -06:00
David Howells
07073eb01c splice: Add a func to do a splice from a buffered file without ITER_PIPE
Provide a function to do splice read from a buffered file, pulling the
folios out of the pagecache directly by calling filemap_get_pages() to do
any required reading and then pasting the returned folios into the pipe.

A helper function is provided to do the actual folio pasting and will
handle multipage folios by splicing as many of the relevant subpages as
will fit into the pipe.

The code is loosely based on filemap_read() and might belong in
mm/filemap.c with that as it needs to use filemap_get_pages().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20 17:25:43 -06:00
David Howells
dd5b9d003e mm: Pass info, not iter, into filemap_get_pages()
filemap_get_pages() and a number of functions that it calls take an
iterator to provide two things: the number of bytes to be got from the file
specified and whether partially uptodate pages are allowed.  Change these
functions so that this information is passed in directly.  This allows it
to be called without having an iterator to hand.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Matthew Wilcox <willy@infradead.org>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20 17:25:43 -06:00
Qian Yingjin
5956592ce3 mm/filemap: fix page end in filemap_get_read_batch
I was running traces of the read code against an RAID storage system to
understand why read requests were being misaligned against the underlying
RAID strips.  I found that the page end offset calculation in
filemap_get_read_batch() was off by one.

When a read is submitted with end offset 1048575, then it calculates the
end page for read of 256 when it should be 255.  "last_index" is the index
of the page beyond the end of the read and it should be skipped when get a
batch of pages for read in @filemap_get_read_batch().

The below simple patch fixes the problem.  This code was introduced in
kernel 5.12.

Link: https://lkml.kernel.org/r/20230208022400.28962-1-coolqyj@163.com
Fixes: cbd59c48ae ("mm/filemap: use head pages in generic_file_buffered_read")
Signed-off-by: Qian Yingjin <qian@ddn.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-16 18:11:58 -08:00
Matthew Wilcox (Oracle)
3e629597b8 filemap: add mapping_read_folio_gfp()
This is like read_cache_page_gfp() except it returns the folio instead
of the precise page.

Link: https://lkml.kernel.org/r/20230206162520.4029022-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mark Hemment <markhemm@googlemail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:42 -08:00
Liam R. Howlett
0503ea8f5b mm/mmap: remove __vma_adjust()
Inline the work of __vma_adjust() into vma_merge().  This reduces code
size and has the added benefits of the comments for the cases being
located with the code.

Change the comments referencing vma_adjust() accordingly.

[Liam.Howlett@oracle.com: fix vma_merge() offset when expanding the next vma]
  Link: https://lkml.kernel.org/r/20230130195713.2881766-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230120162650.984577-49-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:38 -08:00
Matthew Wilcox (Oracle)
eff3b364b4 filemap: convert filemap_range_has_page() to use a folio
The folio isn't returned from this function, so this is an entirely
internal change.

Link: https://lkml.kernel.org/r/20230116193941.2148487-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:21 -08:00
Matthew Wilcox (Oracle)
8808ecab3a filemap: convert filemap_map_pmd() to take a folio
Patch series "Some more filemap folio conversions".

Three more places which could easily be converted to folios.  The third
one fixes a minor bug in readahead_expand(), but it's only a performance
bug and there are few users of readahead_expand(), so I don't think it's
worth backporting.


This patch (of 3):

Save a few calls to compound_head().  We specify exactly which page from
the folio to use by passing in start_pgoff, which means this will work for
a folio which is larger than PMD size.  The rest of the VM isn't prepared
for that yet, but now this function is.

Link: https://lkml.kernel.org/r/20230116193941.2148487-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230116193941.2148487-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:21 -08:00
Vishal Moola (Oracle)
c5792d9384 filemap: remove find_get_pages_range_tag()
All callers to find_get_pages_range_tag(), find_get_pages_tag(),
pagevec_lookup_range_tag(), and pagevec_lookup_tag() have been removed.

Link: https://lkml.kernel.org/r/20230104211448.4804-24-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:18 -08:00
Vishal Moola (Oracle)
6817ef514e filemap: convert __filemap_fdatawait_range() to use filemap_get_folios_tag()
Convert function to use folios.  This is in preparation for the removal of
find_get_pages_range_tag().  This change removes 2 calls to
compound_head().

Link: https://lkml.kernel.org/r/20230104211448.4804-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcow (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:13 -08:00
Vishal Moola (Oracle)
247f9e1fee filemap: add filemap_get_folios_tag()
This is the equivalent of find_get_pages_range_tag(), except for folios
instead of pages.

One noteable difference is filemap_get_folios_tag() does not take in a
maximum pages argument.  It instead tries to fill a folio batch and stops
either once full (15 folios) or reaching the end of the search range.

The new function supports large folios, the initial function did not since
all callers don't use large folios.

Link: https://lkml.kernel.org/r/20230104211448.4804-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcow (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:13 -08:00
Vishal Moola (Oracle)
3720dd6dca filemap: convert replace_page_cache_page() to replace_page_cache_folio()
Patch series "Removing the lru_cache_add() wrapper".

This patchset replaces all calls of lru_cache_add() with the folio
equivalent: folio_add_lru().  This is allows us to get rid of the wrapper
The series passes xfstests and the userfaultfd selftests.


This patch (of 5):

Eliminates 7 calls to compound_head().

Link: https://lkml.kernel.org/r/20221101175326.13265-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20221101175326.13265-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:12 -08:00
Brian Foster
feeb9b2695 filemap: skip write and wait if end offset precedes start
Patch series "filemap: skip write and wait if end offset precedes start",
v2.

A fix for the odd write and wait behavior described in the patch 1 commit
log.  Technically patch 1 could simply remove the check rather than lift
it into the callers, but this seemed a bit more user friendly to me. 
Patch 2 is appended after observation that fadvise() interacted poorly
with the v1 patch.  This is no longer a problem with v2, making patch 2
purely a cleanup.

This series survived both fstests and ltp regression runs without
observable problems.  I had (end < start) warning checks in each relevant
function, with fadvise() being the only caller that triggered them.  That
said, I dropped the warnings after testing because there seemed to much
potential for noise from the various other callers.


This patch (of 2):

A call to file[map]_write_and_wait_range() with an end offset that
precedes the start offset but happens to land in the same page can trigger
writeback submission but fails to wait on the submitted page.  Writeback
submission occurs because __filemap_fdatawrite_range() passes both offsets
down into write_cache_pages(), which rounds down to page indexes before it
starts processing writeback.  However, __filemap_fdatawait_range()
immediately returns if the byte-granular end offset precedes the start
offset.

This behavior was observed in the form of unpredictable latency from a
frequent write and wait call with incorrect parameters.  The behavior gave
the impression that the fdatawait path might occasionally fail to wait on
writeback, but further investigation showed the latency was from
write_cache_pages() waiting on writeback state to clear for a page already
under writeback.  Therefore, this indicated that fdatawait actually never
waits on writeback in this particular situation.

The byte granular check in __filemap_fdatawait_range() goes all the way
back to the old wait_on_page_writeback() helper.  It originally used page
offsets and so would have waited in this problematic case.  That changed
to byte granularity file offsets in commit 94004ed726 ("kill
wait_on_page_writeback_range"), which subtly changed this behavior.  The
check itself has become somewhat redundant since the error checking code
that used to follow the wait loop (at the time of the aforementioned
commit) has now been removed and lifted into the higher level callers.

Therefore, we can restore historical fdatawait behavior by simply removing
the check.  Since the current fdatawait behavior has been in place for
quite some time and is consistent with other interfaces that use file
offsets, instead lift the check into the file[map]_write_and_wait_range()
helpers to provide consistent behavior between the write and wait.

Link: https://lkml.kernel.org/r/20221128155632.3950447-1-bfoster@redhat.com
Link: https://lkml.kernel.org/r/20221128155632.3950447-2-bfoster@redhat.com
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-11 18:12:10 -08:00
Vishal Moola (Oracle)
9fb6beea79 filemap: find_get_entries() now updates start offset
Initially, find_get_entries() was being passed in the start offset as a
value.  That left the calculation of the offset to the callers.  This led
to complexity in the callers trying to keep track of the index.

Now find_get_entries() takes in a pointer to the start offset and updates
the value to be directly after the last entry found.  If no entry is
found, the offset is not changed.  This gets rid of multiple hacky
calculations that kept track of the start offset.

Link: https://lkml.kernel.org/r/20221017161800.2003-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:12 -08:00
Vishal Moola (Oracle)
3392ca1218 filemap: find_lock_entries() now updates start offset
Patch series "Rework find_get_entries() and find_lock_entries()", v3.

Originally the callers of find_get_entries() and find_lock_entries() were
keeping track of the start index themselves as they traverse the search
range.

This resulted in hacky code such as in shmem_undo_range():

			index = folio->index + folio_nr_pages(folio) - 1;

where the - 1 is only present to stay in the right spot after incrementing
index later.  This sort of calculation was also being done on every folio
despite not even using index later within that function.

These patches change find_get_entries() and find_lock_entries() to
calculate the new index instead of leaving it to the callers so we can
avoid all these complications.


This patch (of 2):

Initially, find_lock_entries() was being passed in the start offset as a
value.  That left the calculation of the offset to the callers.  This led
to complexity in the callers trying to keep track of the index.

Now find_lock_entries() takes in a pointer to the start offset and updates
the value to be directly after the last entry found.  If no entry is
found, the offset is not changed.  This gets rid of multiple hacky
calculations that kept track of the start offset.

Link: https://lkml.kernel.org/r/20221017161800.2003-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20221017161800.2003-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-08 17:37:12 -08:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Alexander Potapenko
1468c6f455 mm: fs: initialize fsdata passed to write_begin/write_end interface
Functions implementing the a_ops->write_end() interface accept the `void
*fsdata` parameter that is supposed to be initialized by the corresponding
a_ops->write_begin() (which accepts `void **fsdata`).

However not all a_ops->write_begin() implementations initialize `fsdata`
unconditionally, so it may get passed uninitialized to a_ops->write_end(),
resulting in undefined behavior.

Fix this by initializing fsdata with NULL before the call to
write_begin(), rather than doing so in all possible a_ops implementations.

This patch covers only the following cases found by running x86 KMSAN
under syzkaller:

 - generic_perform_write()
 - cont_expand_zero() and generic_cont_expand_simple()
 - page_symlink()

Other cases of passing uninitialized fsdata may persist in the codebase.

Link: https://lkml.kernel.org/r/20220915150417.722975-43-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:25 -07:00
Ke Sun
c195c32157 mm/filemap: make folio_put_wait_locked static
It's only used in mm/filemap.c, since commit <ffa65753c431>
("mm/migrate.c: rework migration_entry_wait() to not take a pageref").

Make it static.

Link: https://lkml.kernel.org/r/20220914021738.3228011-1-sunke@kylinos.cn
Signed-off-by: Ke Sun <sunke@kylinos.cn>
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:15 -07:00
Vishal Moola (Oracle)
b05f41a1aa filemap: convert filemap_range_has_writeback() to use folios
Removes 3 calls to compound_head().

Link: https://lkml.kernel.org/r/20220905214557.868606-1-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:56 -07:00
Yang Yang
aa1cf99b87 delayacct: support re-entrance detection of thrashing accounting
Once upon a time, we only support accounting thrashing of page cache. 
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].

For page cache thrashing accounting, there is no suitable place to do it
in fs level likes swap_readpage().  So we have to do it in
folio_wait_bit_common().

Then for anonymous pages thrashing accounting, we have to do it in both
swap_readpage() and folio_wait_bit_common().  This likes PSI, so we should
let thrashing accounting supports re-entrance detection.

This patch is to prepare complete thrashing accounting, and is based on
patch "filemap: make the accounting of thrashing more consistent".

[1] commit aae466b005 ("mm/swap: implement workingset detection for anonymous LRU")

Link: https://lkml.kernel.org/r/20220815071134.74551-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: wangyong <wang.yong12@zte.com.cn>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:07 -07:00
Yang Yang
f347c9d269 filemap: make the accounting of thrashing more consistent
Once upon a time, we only support accounting thrashing of page cache. 
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].

So let delayacct account both the thrashing of page cache and anonymous
pages, this could make the codes more consistent and simpler.

[1] commit aae466b005 ("mm/swap: implement workingset detection for anonymous LRU")

Link: https://lkml.kernel.org/r/20220805033838.1714674-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:06 -07:00
Christoph Hellwig
176042404e mm: add PSI accounting around ->read_folio and ->readahead calls
PSI tries to account for the cost of bringing back in pages discarded by
the MM LRU management.  Currently the prime place for that is hooked into
the bio submission path, which is a rather bad place:

 - it does not actually account I/O for non-block file systems, of which
   we have many
 - it adds overhead and a layering violation to the block layer

Add the accounting into the two places in the core MM code that read
pages into an address space by calling into ->read_folio and ->readahead
so that the entire file system operations are covered, to broaden
the coverage and allow removing the accounting in the block layer going
forward.

As psi_memstall_enter can deal with nested calls this will not lead to
double accounting even while the bio annotations are still present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220915094200.139713-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-20 08:24:38 -06:00