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756 commits

Author SHA1 Message Date
Linus Torvalds
14726903c8 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
2021-09-03 10:08:28 -07:00
Johannes Weiner
3047250972 mm: remove irqsave/restore locking from contexts with irqs enabled
The page cache deletion paths all have interrupts enabled, so no need to
use irqsafe/irqrestore locking variants.

They used to have irqs disabled by the memcg lock added in commit
c4843a7593 ("memcg: add per cgroup dirty page accounting"), but that has
since been replaced by memcg taking the page lock instead, commit
0a31bc97c8 ("mm: memcontrol: rewrite uncharge AP").

Link: https://lkml.kernel.org/r/20210614211904.14420-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:10 -07:00
Linus Torvalds
87045e6546 for-5.15-tag
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Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The highlights of this round are integrations with fs-verity and
  idmapped mounts, the rest is usual mix of minor improvements, speedups
  and cleanups.

  There are some patches outside of btrfs, namely updating some VFS
  interfaces, all straightforward and acked.

  Features:

   - fs-verity support, using standard ioctls, backward compatible with
     read-only limitation on inodes with previously enabled fs-verity

   - idmapped mount support

   - make mount with rescue=ibadroots more tolerant to partially damaged
     trees

   - allow raid0 on a single device and raid10 on two devices,
     degenerate cases but might be useful as an intermediate step during
     conversion to other profiles

   - zoned mode block group auto reclaim can be disabled via sysfs knob

  Performance improvements:

   - continue readahead of node siblings even if target node is in
     memory, could speed up full send (on sample test +11%)

   - batching of delayed items can speed up creating many files

   - fsync/tree-log speedups
       - avoid unnecessary work (gains +2% throughput, -2% run time on
         sample load)
       - reduced lock contention on renames (on dbench +4% throughput,
         up to -30% latency)

  Fixes:

   - various zoned mode fixes

   - preemptive flushing threshold tuning, avoid excessive work on
     almost full filesystems

  Core:

   - continued subpage support, preparation for implementing remaining
     features like compression and defragmentation; with some
     limitations, write is now enabled on 64K page systems with 4K
     sectors, still considered experimental
       - no readahead on compressed reads
       - inline extents disabled
       - disabled raid56 profile conversion and mount

   - improved flushing logic, fixing early ENOSPC on some workloads

   - inode flags have been internally split to read-only and read-write
     incompat bit parts, used by fs-verity

   - new tree items for fs-verity
       - descriptor item
       - Merkle tree item

   - inode operations extended to be namespace-aware

   - cleanups and refactoring

  Generic code changes:

   - fs: new export filemap_fdatawrite_wbc

   - fs: removed sync_inode

   - block: bio_trim argument type fixups

   - vfs: add namespace-aware lookup"

* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
  btrfs: reset replace target device to allocation state on close
  btrfs: zoned: fix ordered extent boundary calculation
  btrfs: do not do preemptive flushing if the majority is global rsv
  btrfs: reduce the preemptive flushing threshold to 90%
  btrfs: tree-log: check btrfs_lookup_data_extent return value
  btrfs: avoid unnecessarily logging directories that had no changes
  btrfs: allow idmapped mount
  btrfs: handle ACLs on idmapped mounts
  btrfs: allow idmapped INO_LOOKUP_USER ioctl
  btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
  btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
  btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
  btrfs: allow idmapped SNAP_DESTROY ioctls
  btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
  btrfs: check whether fsgid/fsuid are mapped during subvolume creation
  btrfs: allow idmapped permission inode op
  btrfs: allow idmapped setattr inode op
  btrfs: allow idmapped tmpfile inode op
  btrfs: allow idmapped symlink inode op
  btrfs: allow idmapped mkdir inode op
  ...
2021-08-31 09:41:22 -07:00
Josef Bacik
5a798493b8 fs: add a filemap_fdatawrite_wbc helper
Btrfs sometimes needs to flush dirty pages on a bunch of dirty inodes in
order to reclaim metadata reservations.  Unfortunately most helpers in
this area are too smart for us:

1) The normal filemap_fdata* helpers only take range and sync modes, and
   don't give any indication of how much was written, so we can only
   flush full inodes, which isn't what we want in most cases.
2) The normal writeback path requires us to have the s_umount sem held,
   but we can't unconditionally take it in this path because we could
   deadlock.
3) The normal writeback path also skips inodes with I_SYNC set if we
   write with WB_SYNC_NONE.  This isn't the behavior we want under heavy
   ENOSPC pressure, we want to actually make sure the pages are under
   writeback before returning, and if another thread is in the middle of
   writing the file we may return before they're under writeback and
   miss our ordered extents and not properly wait for completion.
4) sync_inode() uses the normal writeback path and has the same problem
   as #3.

What we really want is to call do_writepages() with our wbc.  This way
we can make sure that writeback is actually started on the pages, and we
can control how many pages are written as a whole as we write many
inodes using the same wbc.  Accomplish this with a new helper that does
just that so we can use it for our ENOSPC flushing infrastructure.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23 13:19:07 +02:00
Jan Kara
7506ae6a70 mm: Add functions to lock invalidate_lock for two mappings
Some operations such as reflinking blocks among files will need to lock
invalidate_lock for two mappings. Add helper functions to do that.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 14:29:00 +02:00
Jan Kara
730633f0b7 mm: Protect operations adding pages to page cache with invalidate_lock
Currently, serializing operations such as page fault, read, or readahead
against hole punching is rather difficult. The basic race scheme is
like:

fallocate(FALLOC_FL_PUNCH_HOLE)			read / fault / ..
  truncate_inode_pages_range()
						  <create pages in page
						   cache here>
  <update fs block mapping and free blocks>

Now the problem is in this way read / page fault / readahead can
instantiate pages in page cache with potentially stale data (if blocks
get quickly reused). Avoiding this race is not simple - page locks do
not work because we want to make sure there are *no* pages in given
range. inode->i_rwsem does not work because page fault happens under
mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes
the performance for mixed read-write workloads suffer.

So create a new rw_semaphore in the address_space - invalidate_lock -
that protects adding of pages to page cache for page faults / reads /
readahead.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 13:14:27 +02:00
Jan Kara
9608703e48 mm: Fix comments mentioning i_mutex
inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-12 18:31:16 +02:00
Linus Torvalds
d3acb15a3a Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
 "iov_iter cleanups and fixes.

  There are followups, but this is what had sat in -next this cycle. IMO
  the macro forest in there became much thinner and easier to follow..."

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  csum_and_copy_to_pipe_iter(): leave handling of csum_state to caller
  clean up copy_mc_pipe_to_iter()
  pipe_zero(): we don't need no stinkin' kmap_atomic()...
  iov_iter: clean csum_and_copy_...() primitives up a bit
  copy_page_from_iter(): don't need kmap_atomic() for kvec/bvec cases
  copy_page_to_iter(): don't bother with kmap_atomic() for bvec/kvec cases
  iterate_xarray(): only of the first iteration we might get offset != 0
  pull handling of ->iov_offset into iterate_{iovec,bvec,xarray}
  iov_iter: make iterator callbacks use base and len instead of iovec
  iov_iter: make the amount already copied available to iterator callbacks
  iov_iter: get rid of separate bvec and xarray callbacks
  iov_iter: teach iterate_{bvec,xarray}() about possible short copies
  iterate_bvec(): expand bvec.h macro forest, massage a bit
  iov_iter: unify iterate_iovec and iterate_kvec
  iov_iter: massage iterate_iovec and iterate_kvec to logics similar to iterate_bvec
  iterate_and_advance(): get rid of magic in case when n is 0
  csum_and_copy_to_iter(): massage into form closer to csum_and_copy_from_iter()
  iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
  [xarray] iov_iter_npages(): just use DIV_ROUND_UP()
  iov_iter_npages(): don't bother with iterate_all_kinds()
  ...
2021-07-03 11:30:04 -07:00
Dan Schatzberg
04f94e3fbe mm: charge active memcg when no mm is set
set_active_memcg() worked for kernel allocations but was silently ignored
for user pages.

This patch establishes a precedence order for who gets charged:

1. If there is a memcg associated with the page already, that memcg is
   charged. This happens during swapin.

2. If an explicit mm is passed, mm->memcg is charged. This happens
   during page faults, which can be triggered in remote VMs (eg gup).

3. Otherwise consult the current process context. If there is an
   active_memcg, use that. Otherwise, current->mm->memcg.

Previously, if a NULL mm was passed to mem_cgroup_charge (case 3) it would
always charge the root cgroup.  Now it looks up the active_memcg first
(falling back to charging the root cgroup if not set).

Link: https://lkml.kernel.org/r/20210610173944.1203706-3-schatzberg.dan@gmail.com
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:50 -07:00
Al Viro
f0b65f39ac iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the
callers do *not* need to do iov_iter_advance() after it.  In case when they end
up consuming less than they'd been given they need to do iov_iter_revert() on
everything they had not consumed.  That, however, needs to be done only on slow
paths.

All in-tree callers converted.  And that kills the last user of iterate_all_kinds()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10 11:45:14 -04:00
Al Viro
bc1bb416bb generic_perform_write()/iomap_write_actor(): saner logics for short copy
if we run into a short copy and ->write_end() refuses to advance at all,
use the amount we'd managed to copy for the next iteration to handle.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-02 17:50:44 -04:00
Ingo Molnar
f0953a1bba mm: fix typos in comments
Fix ~94 single-word typos in locking code comments, plus a few
very obvious grammar mistakes.

Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com
Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:35 -07:00
Zhiyuan Dai
68d68ff6eb mm/mempool: minor coding style tweaks
Various coding style tweaks to various files under mm/

[daizhiyuan@phytium.com.cn: mm/swapfile: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614223624-16055-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/sparse: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614227288-19363-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/vmscan: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614227649-19853-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/compaction: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614228218-20770-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/oom_kill: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614228360-21168-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/shmem: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614228504-21491-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/page_alloc: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614228613-21754-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/filemap: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1614228936-22337-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/mlock: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1613956588-2453-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/frontswap: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1613962668-15045-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/vmalloc: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1613963379-15988-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/memory_hotplug: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1613971784-24878-1-git-send-email-daizhiyuan@phytium.com.cn
[daizhiyuan@phytium.com.cn: mm/mempolicy: minor coding style tweaks]
  Link: https://lkml.kernel.org/r/1613972228-25501-1-git-send-email-daizhiyuan@phytium.com.cn

Link: https://lkml.kernel.org/r/1614222374-13805-1-git-send-email-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:27 -07:00
Matthew Wilcox (Oracle)
7f0e07fb02 dax: account DAX entries as nrpages
Simplify mapping_needs_writeback() by accounting DAX entries as pages
instead of exceptional entries.

Link: https://lkml.kernel.org/r/20201026151849.24232-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:19 -07:00
Matthew Wilcox (Oracle)
46be67b424 mm: stop accounting shadow entries
We no longer need to keep track of how many shadow entries are present in
a mapping.  This saves a few writes to the inode and memory barriers.

Link: https://lkml.kernel.org/r/20201026151849.24232-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:19 -07:00
Rui Sun
4b17f030fd mm/filemap: update stale comment
Commit a6de4b4873 ("mm: convert find_get_entry to return the head page")
uses @index instead of @offset, but the comment is stale, update it.

Link: https://lkml.kernel.org/r/1617948260-50724-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Rui Sun <sunrui26@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:37 -07:00
Matthew Wilcox (Oracle)
79e3094c53 mm/filemap: drop check for truncated page after I/O
If the I/O completed successfully, the page will remain Uptodate, even
if it is subsequently truncated.  If the I/O completed with an error,
this check would cause us to retry the I/O if the page were truncated
before we woke up.  There is no need to retry the I/O; the I/O to fill
the page failed, so we can legitimately just return -EIO.

This code was originally added by commit 56f0d5fe6851 ("[PATCH]
readpage-vs-invalidate fix") in 2005 (this commit ID is from the
linux-fullhistory tree; it is also commit ba1f08f14b52 in tglx-history).

At the time, truncate_complete_page() called ClearPageUptodate(), and so
this was fixing a real bug.  In 2008, commit 84209e02de ("mm: dont clear
PG_uptodate on truncate/invalidate") removed the call to
ClearPageUptodate, and this check has been unnecessary ever since.

It doesn't do any real harm, but there's no need to keep it.

Link: https://lkml.kernel.org/r/20210303222547.1056428-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:37 -07:00
Matthew Wilcox (Oracle)
d31fa86a27 mm/filemap: use filemap_read_page in filemap_fault
After splitting generic_file_buffered_read() into smaller parts, it turns
out we can reuse one of the parts in filemap_fault().  This fixes an
oversight -- waiting for the I/O to complete is now interruptible by a
fatal signal.  And it saves us a few bytes of text in an unlikely path.

  $ ./scripts/bloat-o-meter before.o after.o
  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-207 (-207)
  Function                                     old     new   delta
  filemap_fault                               2187    1980    -207
  Total: Before=37491, After=37284, chg -0.55%

Link: https://lkml.kernel.org/r/20210226140011.2883498-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:36 -07:00
Jens Axboe
7a60d6d7b3 mm: use filemap_range_needs_writeback() for O_DIRECT reads
For the generic page cache read helper, use the better variant of checking
for the need to call filemap_write_and_wait_range() when doing O_DIRECT
reads.  This avoids falling back to the slow path for IOCB_NOWAIT, if
there are no pages to wait for (or write out).

Link: https://lkml.kernel.org/r/20210224164455.1096727-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:36 -07:00
Jens Axboe
63135aa386 mm: provide filemap_range_needs_writeback() helper
Patch series "Improve IOCB_NOWAIT O_DIRECT reads", v3.

An internal workload complained because it was using too much CPU, and
when I took a look, we had a lot of io_uring workers going to town.

For an async buffered read like workload, I am normally expecting _zero_
offloads to a worker thread, but this one had tons of them.  I'd drop
caches and things would look good again, but then a minute later we'd
regress back to using workers.  Turns out that every minute something
was reading parts of the device, which would add page cache for that
inode.  I put patches like these in for our kernel, and the problem was
solved.

Don't -EAGAIN IOCB_NOWAIT dio reads just because we have page cache
entries for the given range.  This causes unnecessary work from the
callers side, when the IO could have been issued totally fine without
blocking on writeback when there is none.

This patch (of 3):

For O_DIRECT reads/writes, we check if we need to issue a call to
filemap_write_and_wait_range() to issue and/or wait for writeback for any
page in the given range.  The existing mechanism just checks for a page in
the range, which is suboptimal for IOCB_NOWAIT as we'll fallback to the
slow path (and needing retry) if there's just a clean page cache page in
the range.

Provide filemap_range_needs_writeback() which tries a little harder to
check if we actually need to issue and/or wait for writeback in the range.

Link: https://lkml.kernel.org/r/20210224164455.1096727-1-axboe@kernel.dk
Link: https://lkml.kernel.org/r/20210224164455.1096727-2-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:36 -07:00
Linus Torvalds
820c4bae40 Network filesystem helper library
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Merge tag 'netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull network filesystem helper library updates from David Howells:
 "Here's a set of patches for 5.13 to begin the process of overhauling
  the local caching API for network filesystems. This set consists of
  two parts:

  (1) Add a helper library to handle the new VM readahead interface.

      This is intended to be used unconditionally by the filesystem
      (whether or not caching is enabled) and provides a common
      framework for doing caching, transparent huge pages and, in the
      future, possibly fscrypt and read bandwidth maximisation. It also
      allows the netfs and the cache to align, expand and slice up a
      read request from the VM in various ways; the netfs need only
      provide a function to read a stretch of data to the pagecache and
      the helper takes care of the rest.

  (2) Add an alternative fscache/cachfiles I/O API that uses the kiocb
      facility to do async DIO to transfer data to/from the netfs's
      pages, rather than using readpage with wait queue snooping on one
      side and vfs_write() on the other. It also uses less memory, since
      it doesn't do buffered I/O on the backing file.

      Note that this uses SEEK_HOLE/SEEK_DATA to locate the data
      available to be read from the cache. Whilst this is an improvement
      from the bmap interface, it still has a problem with regard to a
      modern extent-based filesystem inserting or removing bridging
      blocks of zeros. Fixing that requires a much greater overhaul.

  This is a step towards overhauling the fscache API. The change is
  opt-in on the part of the network filesystem. A netfs should not try
  to mix the old and the new API because of conflicting ways of handling
  pages and the PG_fscache page flag and because it would be mixing DIO
  with buffered I/O. Further, the helper library can't be used with the
  old API.

  This does not change any of the fscache cookie handling APIs or the
  way invalidation is done at this time.

  In the near term, I intend to deprecate and remove the old I/O API
  (fscache_allocate_page{,s}(), fscache_read_or_alloc_page{,s}(),
  fscache_write_page() and fscache_uncache_page()) and eventually
  replace most of fscache/cachefiles with something simpler and easier
  to follow.

  This patchset contains the following parts:

   - Some helper patches, including provision of an ITER_XARRAY iov
     iterator and a function to do readahead expansion.

   - Patches to add the netfs helper library.

   - A patch to add the fscache/cachefiles kiocb API.

   - A pair of patches to fix some review issues in the ITER_XARRAY and
     read helpers as spotted by Al and Willy.

  Jeff Layton has patches to add support in Ceph for this that he
  intends for this merge window. I have a set of patches to support AFS
  that I will post a separate pull request for.

  With this, AFS without a cache passes all expected xfstests; with a
  cache, there's an extra failure, but that's also there before these
  patches. Fixing that probably requires a greater overhaul. Ceph also
  passes the expected tests.

  I also have patches in a separate branch to tidy up the handling of
  PG_fscache/PG_private_2 and their contribution to page refcounting in
  the core kernel here, but I haven't included them in this set and will
  route them separately"

Link: https://lore.kernel.org/lkml/3779937.1619478404@warthog.procyon.org.uk/

* tag 'netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  netfs: Miscellaneous fixes
  iov_iter: Four fixes for ITER_XARRAY
  fscache, cachefiles: Add alternate API to use kiocb for read/write to cache
  netfs: Add a tracepoint to log failures that would be otherwise unseen
  netfs: Define an interface to talk to a cache
  netfs: Add write_begin helper
  netfs: Gather stats
  netfs: Add tracepoints
  netfs: Provide readahead and readpage netfs helpers
  netfs, mm: Add set/end/wait_on_page_fscache() aliases
  netfs, mm: Move PG_fscache helper funcs to linux/netfs.h
  netfs: Documentation for helper library
  netfs: Make a netfs helper module
  mm: Implement readahead_control pageset expansion
  mm/readahead: Handle ractl nr_pages being modified
  fs: Document file_ra_state
  mm/filemap: Pass the file_ra_state in the ractl
  mm: Add set/end/wait functions for PG_private_2
  iov_iter: Add ITER_XARRAY
2021-04-27 13:08:12 -07:00
Hugh Dickins
ed98b0159f mm/filemap: fix mapping_seek_hole_data on THP & 32-bit
No problem on 64-bit, or without huge pages, but xfstests generic/285
and other SEEK_HOLE/SEEK_DATA tests have regressed on huge tmpfs, and on
32-bit architectures, with the new mapping_seek_hole_data().  Several
different bugs turned out to need fixing.

u64 cast to stop losing bits when converting unsigned long to loff_t
(and let's use shifts throughout, rather than mixed with * and /).

Use round_up() when advancing pos, to stop assuming that pos was already
THP-aligned when advancing it by THP-size.  (This use of round_up()
assumes that any THP has THP-aligned index: true at present and true
going forward, but could be recoded to avoid the assumption.)

Use xas_set() when iterating away from a THP, so that xa_index stays in
synch with start, instead of drifting away to return bogus offset.

Check start against end to avoid wrapping 32-bit xa_index to 0 (and to
handle these additional cases, seek_data or not, it's easier to break
the loop than goto: so rearrange exit from the function).

[hughd@google.com: remove unneeded u64 casts, per Matthew]
  Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104221347240.1170@eggly.anvils

Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104211737410.3299@eggly.anvils
Fixes: 41139aa4c3 ("mm/filemap: add mapping_seek_hole_data")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-23 14:42:39 -07:00
Hugh Dickins
2d11e73815 mm/filemap: fix find_lock_entries hang on 32-bit THP
No problem on 64-bit, or without huge pages, but xfstests generic/308
hung uninterruptibly on 32-bit huge tmpfs.

Since commit 0cc3b0ec23 ("Clarify (and fix) in 4.13 MAX_LFS_FILESIZE
macros"), MAX_LFS_FILESIZE is only a PAGE_SIZE away from wrapping 32-bit
xa_index to 0, so the new find_lock_entries() has to be extra careful
when handling a THP.

Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104211735430.3299@eggly.anvils
Fixes: 5c211ba29d ("mm: add and use find_lock_entries")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-23 14:42:39 -07:00
Matthew Wilcox (Oracle)
fcd9ae4f7f mm/filemap: Pass the file_ra_state in the ractl
For readahead_expand(), we need to modify the file ra_state, so pass it
down by adding it to the ractl.  We have to do this because it's not always
the same as f_ra in the struct file that is already being passed.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
Link: https://lore.kernel.org/r/20210407201857.3582797-2-willy@infradead.org/
Link: https://lore.kernel.org/r/161789067431.6155.8063840447229665720.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 09:25:00 +01:00
David Howells
73e10ded33 mm: Add set/end/wait functions for PG_private_2
Add three functions to manipulate PG_private_2:

 (*) set_page_private_2() - Set the flag and take an appropriate reference
     on the flagged page.

 (*) end_page_private_2() - Clear the flag, drop the reference and wake up
     any waiters, somewhat analogously with end_page_writeback().

 (*) wait_on_page_private_2() - Wait for the flag to be cleared.

Wrappers will need to be placed in the netfs lib header in the patch that
adds that.

[This implements a suggestion by Linus[1] to not mix the terminology of
 PG_private_2 and PG_fscache in the mm core function]

Changes:
v7:
- Use compound_head() in all the functions to make them THP safe[6].

v5:
- Add set and end functions, calling the end function end rather than
  unlock[3].
- Keep a ref on the page when PG_private_2 is set[4][5].

v4:
- Remove extern from the declaration[2].

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christoph Hellwig <hch@lst.de>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/1330473.1612974547@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/CAHk-=wjgA-74ddehziVk=XAEMTKswPu1Yw4uaro1R3ibs27ztw@mail.gmail.com/ [1]
Link: https://lore.kernel.org/r/20210216102659.GA27714@lst.de/ [2]
Link: https://lore.kernel.org/r/161340387944.1303470.7944159520278177652.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539528910.286939.1252328699383291173.stgit@warthog.procyon.org.uk # v4
Link: https://lore.kernel.org/r/20210321105309.GG3420@casper.infradead.org [3]
Link: https://lore.kernel.org/r/CAHk-=wh+2gbF7XEjYc=HV9w_2uVzVf7vs60BPz0gFA=+pUm3ww@mail.gmail.com/ [4]
Link: https://lore.kernel.org/r/CAHk-=wjSGsRj7xwhSMQ6dAQiz53xA39pOG+XA_WeTgwBBu4uqg@mail.gmail.com/ [5]
Link: https://lore.kernel.org/r/20210408145057.GN2531743@casper.infradead.org/ [6]
Link: https://lore.kernel.org/r/161653788200.2770958.9517755716374927208.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789066013.6155.9816857201817288382.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 09:20:49 +01:00
Matthew Wilcox (Oracle)
cf2039af1a mm: pass pvec directly to find_get_entries
All callers of find_get_entries() use a pvec, so pass it directly instead
of manipulating it in the caller.

Link: https://lkml.kernel.org/r/20201112212641.27837-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
ca122fe40e mm: add an 'end' parameter to find_get_entries
This simplifies the callers and leads to a more efficient implementation
since the XArray has this functionality already.

Link: https://lkml.kernel.org/r/20201112212641.27837-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
5c211ba29d mm: add and use find_lock_entries
We have three functions (shmem_undo_range(), truncate_inode_pages_range()
and invalidate_mapping_pages()) which want exactly this function, so add
it to filemap.c.  Before this patch, shmem_undo_range() would split any
compound page which overlaps either end of the range being punched in both
the first and second loops through the address space.  After this patch,
that functionality is left for the second loop, which is arguably more
appropriate since the first loop is supposed to run through all the pages
quickly, and splitting a page can sleep.

[willy@infradead.org: add assertion]
  Link: https://lkml.kernel.org/r/20201124041507.28996-3-willy@infradead.org

Link: https://lkml.kernel.org/r/20201112212641.27837-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
54fa39ac2e iomap: use mapping_seek_hole_data
Enhance mapping_seek_hole_data() to handle partially uptodate pages and
convert the iomap seek code to call it.

Link: https://lkml.kernel.org/r/20201112212641.27837-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
41139aa4c3 mm/filemap: add mapping_seek_hole_data
Rewrite shmem_seek_hole_data() and move it to filemap.c.

[willy@infradead.org: don't put an xa_is_value() page]
  Link: https://lkml.kernel.org/r/20201124041507.28996-4-willy@infradead.org

Link: https://lkml.kernel.org/r/20201112212641.27837-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
c7bad633e6 mm/filemap: add helper for finding pages
There is a lot of common code in find_get_entries(),
find_get_pages_range() and find_get_pages_range_tag().  Factor out
find_get_entry() which simplifies all three functions.

[willy@infradead.org: remove VM_BUG_ON_PAGE()]
  Link: https://lkml.kernel.org/r/20201124041507.28996-2-willy@infradead.orgLink: https://lkml.kernel.org/r/20201112212641.27837-7-willy@infradead.org

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
bc5a301120 mm/filemap: rename find_get_entry to mapping_get_entry
find_get_entry doesn't "find" anything.  It returns the entry at a
particular index.

Link: https://lkml.kernel.org/r/20201112212641.27837-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
44835d20b2 mm: add FGP_ENTRY
The functionality of find_lock_entry() and find_get_entry() can be
provided by pagecache_get_page(), which lets us delete find_lock_entry()
and make find_get_entry() static.

Link: https://lkml.kernel.org/r/20201112212641.27837-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:59 -08:00
Matthew Wilcox (Oracle)
c49f50d198 mm: make pagecache tagged lookups return only head pages
Patch series "Overhaul multi-page lookups for THP", v4.

This THP prep patchset changes several page cache iteration APIs to only
return head pages.

 - It's only possible to tag head pages in the page cache, so only
   return head pages, not all their subpages.
 - Factor a lot of common code out of the various batch lookup routines
 - Add mapping_seek_hole_data()
 - Unify find_get_entries() and pagevec_lookup_entries()
 - Make find_get_entries only return head pages, like find_get_entry().

These are only loosely connected, but they seem to make sense together as
a series.

This patch (of 14):

Pagecache tags are used for dirty page writeback.  Since dirtiness is
tracked on a per-THP basis, we only want to return the head page rather
than each subpage of a tagged page.  All the filesystems which use huge
pages today are in-memory, so there are no tagged huge pages today.

Link: https://lkml.kernel.org/r/20201112212641.27837-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:40:58 -08:00
Muchun Song
57b2847d3c mm: memcontrol: convert NR_SHMEM_THPS account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_SHMEM_THPS account to pages.  This patch is
consistent with 8f182270df ("mm/swap.c: flush lru pvecs on compound page
arrival").  Doing this also can make the unit of vmstat counters more
unified.  Finally, the unit of the vmstat counters are pages, kB and
bytes.  The B/KB suffix can tell us that the unit is bytes or kB.  The
rest which is without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
bf9ecead53 mm: memcontrol: convert NR_FILE_THPS account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with if hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_FILE_THPS account to pages.  This patch is consistent
with 8f182270df ("mm/swap.c: flush lru pvecs on compound page arrival").
Doing this also can make the unit of vmstat counters more unified.
Finally, the unit of the vmstat counters are pages, kB and bytes.  The
B/KB suffix can tell us that the unit is bytes or kB.  The rest which is
without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Christoph Hellwig
826ea860bc mm/filemap: simplify generic_file_read_iter
Avoid the pointless goto out just for returning retval.

Link: https://lkml.kernel.org/r/20210122160140.223228-19-willy@infradead.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Christoph Hellwig
87fa0f3eb2 mm/filemap: rename generic_file_buffered_read to filemap_read
Rename generic_file_buffered_read to match the naming of filemap_fault,
also update the written parameter to a more descriptive name and improve
the kerneldoc comment.

Link: https://lkml.kernel.org/r/20210122160140.223228-18-willy@infradead.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
aa1ec2f697 mm/filemap: don't relock the page after calling readpage
We don't need to get the page lock again; we just need to wait for the I/O
to finish, so use wait_on_page_locked_killable() like the other callers of
->readpage.

Link: https://lkml.kernel.org/r/20210122160140.223228-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
2642fca647 mm/filemap: restructure filemap_get_pages
Remove the got_pages label, remove indentation, rename find_page to retry,
simplify error handling.

Link: https://lkml.kernel.org/r/20210122160140.223228-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
5963fe0316 mm/filemap: split filemap_readahead out of filemap_get_pages
This simplifies the error handling.

Link: https://lkml.kernel.org/r/20210122160140.223228-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
fce70da3a8 mm/filemap: add filemap_range_uptodate
Move the complicated condition and the calculations out of
filemap_update_page() into its own function.

[willy@infradead.org: unlock page before dropping its refcount]
  Link: https://lkml.kernel.org/r/20210201125229.GO308988@casper.infradead.org

Link: https://lkml.kernel.org/r/20210122160140.223228-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
87d1d7b688 mm/filemap: move the iocb checks into filemap_update_page
We don't need to give up when a non-blocking request sees a !Uptodate
page.  We may be able to satisfy the read from a partially-uptodate page.

Link: https://lkml.kernel.org/r/20210122160140.223228-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
4612aeef09 mm/filemap: convert filemap_update_page to return an errno
Use AOP_TRUNCATED_PAGE to indicate that no error occurred, but the page we
looked up is no longer valid.  In this case, the reference to the page
will have been removed; if we hit any other error, the caller will release
the reference.

Link: https://lkml.kernel.org/r/20210122160140.223228-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
f253e1854c mm/filemap: change filemap_create_page calling conventions
By moving the iocb flag checks to the caller, we can pass the file and the
page index instead of the iocb.  It never needed the iter.  By passing the
pagevec, we can return an errno (or AOP_TRUNCATED_PAGE) instead of an
ERR_PTR.

Link: https://lkml.kernel.org/r/20210122160140.223228-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
68430303c8 mm/filemap: change filemap_read_page calling conventions
Make this function more generic by passing the file instead of the iocb.
Check in the callers whether we should call readpage or not.  Also make it
return an errno / 0 / AOP_TRUNCATED_PAGE, and make calling put_page() the
caller's responsibility.

Link: https://lkml.kernel.org/r/20210122160140.223228-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
33a0f5c6b3 mm/filemap: don't call ->readpage if IOCB_WAITQ is set
The readpage operation can block in many (most?) filesystems, so we should
punt to a work queue instead of calling it.  This was the last caller of
lock_page_for_iocb(), so remove it.

Link: https://lkml.kernel.org/r/20210122160140.223228-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
f32b5dd721 mm/filemap: inline __wait_on_page_locked_async into caller
The previous patch removed wait_on_page_locked_async(), so inline
__wait_on_page_locked_async into __lock_page_async().

Link: https://lkml.kernel.org/r/20210122160140.223228-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
bd8a1f3655 mm/filemap: support readpage splitting a page
For page splitting to succeed, the thread asking to split the page has to
be the only one with a reference to the page.  Calling
wait_on_page_locked() while holding a reference to the page will
effectively prevent this from happening with sufficient threads waiting on
the same page.  Use put_and_wait_on_page_locked() to sleep without holding
a reference to the page, then retry the page lookup after the page is
unlocked.

Since we now get the page lock a little earlier in filemap_update_page(),
we can eliminate a number of duplicate checks.  The original intent
(commit ebded02788 ("avoid unnecessary calls to lock_page when waiting
for IO to complete during a read")) behind getting the page lock later was
to avoid re-locking the page after it has been brought uptodate by another
thread.  We still avoid that because we go through the normal lookup path
again after the winning thread has brought the page uptodate.

Link: https://lkml.kernel.org/r/20210122160140.223228-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
4805462598 mm/filemap: pass a sleep state to put_and_wait_on_page_locked
This is prep work for the next patch, but I think at least one of the
current callers would prefer a killable sleep to an uninterruptible one.

Link: https://lkml.kernel.org/r/20210122160140.223228-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00