Граф коммитов

53 Коммитов

Автор SHA1 Сообщение Дата
Jan Kara a44e84a9b7 ext4: fix deadlock due to mbcache entry corruption
When manipulating xattr blocks, we can deadlock infinitely looping
inside ext4_xattr_block_set() where we constantly keep finding xattr
block for reuse in mbcache but we are unable to reuse it because its
reference count is too big. This happens because cache entry for the
xattr block is marked as reusable (e_reusable set) although its
reference count is too big. When this inconsistency happens, this
inconsistent state is kept indefinitely and so ext4_xattr_block_set()
keeps retrying indefinitely.

The inconsistent state is caused by non-atomic update of e_reusable bit.
e_reusable is part of a bitfield and e_reusable update can race with
update of e_referenced bit in the same bitfield resulting in loss of one
of the updates. Fix the problem by using atomic bitops instead.

This bug has been around for many years, but it became *much* easier
to hit after commit 65f8b80053 ("ext4: fix race when reusing xattr
blocks").

Cc: stable@vger.kernel.org
Fixes: 6048c64b26 ("mbcache: add reusable flag to cache entries")
Fixes: 65f8b80053 ("ext4: fix race when reusing xattr blocks")
Reported-and-tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Reported-by: Thilo Fromm <t-lo@linux.microsoft.com>
Link: https://lore.kernel.org/r/c77bf00f-4618-7149-56f1-b8d1664b9d07@linux.microsoft.com/
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20221123193950.16758-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-12-08 21:49:25 -05:00
Jan Kara 5fc4cbd9fd mbcache: Avoid nesting of cache->c_list_lock under bit locks
Commit 307af6c879 ("mbcache: automatically delete entries from cache
on freeing") started nesting cache->c_list_lock under the bit locks
protecting hash buckets of the mbcache hash table in
mb_cache_entry_create(). This causes problems for real-time kernels
because there spinlocks are sleeping locks while bitlocks stay atomic.
Luckily the nesting is easy to avoid by holding entry reference until
the entry is added to the LRU list. This makes sure we cannot race with
entry deletion.

Cc: stable@kernel.org
Fixes: 307af6c879 ("mbcache: automatically delete entries from cache on freeing")
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220908091032.10513-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-09-30 23:46:52 -04:00
Linus Torvalds 6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Jan Kara 307af6c879 mbcache: automatically delete entries from cache on freeing
Use the fact that entries with elevated refcount are not removed from
the hash and just move removal of the entry from the hash to the entry
freeing time. When doing this we also change the generic code to hold
one reference to the cache entry, not two of them, which makes code
somewhat more obvious.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-10-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:25 -04:00
Jan Kara 75896339e4 mbcache: Remove mb_cache_entry_delete()
Nobody uses mb_cache_entry_delete() anymore. Remove it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-9-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:25 -04:00
Jan Kara 3dc96bba65 mbcache: add functions to delete entry if unused
Add function mb_cache_entry_delete_or_get() to delete mbcache entry if
it is unused and also add a function to wait for entry to become unused
- mb_cache_entry_wait_unused(). We do not share code between the two
deleting function as one of them will go away soon.

CC: stable@vger.kernel.org
Fixes: 82939d7999 ("ext4: convert to mbcache2")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:25 -04:00
Jan Kara 5831891418 mbcache: don't reclaim used entries
Do not reclaim entries that are currently used by somebody from a
shrinker. Firstly, these entries are likely useful. Secondly, we will
need to keep such entries to protect pending increment of xattr block
refcount.

CC: stable@vger.kernel.org
Fixes: 82939d7999 ("ext4: convert to mbcache2")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:25 -04:00
Roman Gushchin e33c267ab7 mm: shrinkers: provide shrinkers with names
Currently shrinkers are anonymous objects.  For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g.  for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

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

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

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

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

[roman.gushchin@linux.dev: fix build warnings]
  Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
  Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:40 -07:00
Thomas Gleixner 09c434b8a0 treewide: Add SPDX license identifier for more missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
Kees Cook 6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Jiang Biao 9ee93ba3c4 mbcache: make sure c_entry_count is not decremented past zero
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
CC: Eric Biggers <ebiggers@google.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Jan Kara <jack@suse.cz>
2018-01-09 23:57:52 -05:00
Eric Biggers bbe45d2460 mbcache: revert "fs/mbcache.c: make count_objects() more robust"
This reverts commit d5dabd6339.

This patch did absolutely nothing, because ->c_entry_count is unsigned.

In addition if there is a bug in how mbcache maintains its entry count,
it needs to be fixed, not just hacked around.  (There is no obvious bug,
though.)

Cc: Jan Kara <jack@suse.cz>
Cc: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-07 16:35:20 -05:00
Alexander Potapenko 3876bbe27d mbcache: initialize entry->e_referenced in mb_cache_entry_create()
KMSAN reported use of uninitialized |entry->e_referenced| in a condition
in mb_cache_shrink():

==================================================================
BUG: KMSAN: use of uninitialized memory in mb_cache_shrink+0x3b4/0xc50 fs/mbcache.c:287
CPU: 2 PID: 816 Comm: kswapd1 Not tainted 4.11.0-rc5+ #2877
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x172/0x1c0 lib/dump_stack.c:52
 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927
 __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469
 mb_cache_shrink+0x3b4/0xc50 fs/mbcache.c:287
 mb_cache_scan+0x67/0x80 fs/mbcache.c:321
 do_shrink_slab mm/vmscan.c:397 [inline]
 shrink_slab+0xc3d/0x12d0 mm/vmscan.c:500
 shrink_node+0x208f/0x2fd0 mm/vmscan.c:2603
 kswapd_shrink_node mm/vmscan.c:3172 [inline]
 balance_pgdat mm/vmscan.c:3289 [inline]
 kswapd+0x160f/0x2850 mm/vmscan.c:3478
 kthread+0x46c/0x5f0 kernel/kthread.c:230
 ret_from_fork+0x29/0x40 arch/x86/entry/entry_64.S:430
chained origin:
 save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:317 [inline]
 kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547
 __msan_store_shadow_origin_1+0xac/0x110 mm/kmsan/kmsan_instr.c:257
 mb_cache_entry_create+0x3b3/0xc60 fs/mbcache.c:95
 ext4_xattr_cache_insert fs/ext4/xattr.c:1647 [inline]
 ext4_xattr_block_set+0x4c82/0x5530 fs/ext4/xattr.c:1022
 ext4_xattr_set_handle+0x1332/0x20a0 fs/ext4/xattr.c:1252
 ext4_xattr_set+0x4d2/0x680 fs/ext4/xattr.c:1306
 ext4_xattr_trusted_set+0x8d/0xa0 fs/ext4/xattr_trusted.c:36
 __vfs_setxattr+0x703/0x790 fs/xattr.c:149
 __vfs_setxattr_noperm+0x27a/0x6f0 fs/xattr.c:180
 vfs_setxattr fs/xattr.c:223 [inline]
 setxattr+0x6ae/0x790 fs/xattr.c:449
 path_setxattr+0x1eb/0x380 fs/xattr.c:468
 SYSC_lsetxattr+0x8d/0xb0 fs/xattr.c:490
 SyS_lsetxattr+0x77/0xa0 fs/xattr.c:486
 entry_SYSCALL_64_fastpath+0x13/0x94
origin:
 save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 [inline]
 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198
 kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337
 kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766
 mb_cache_entry_create+0x283/0xc60 fs/mbcache.c:86
 ext4_xattr_cache_insert fs/ext4/xattr.c:1647 [inline]
 ext4_xattr_block_set+0x4c82/0x5530 fs/ext4/xattr.c:1022
 ext4_xattr_set_handle+0x1332/0x20a0 fs/ext4/xattr.c:1252
 ext4_xattr_set+0x4d2/0x680 fs/ext4/xattr.c:1306
 ext4_xattr_trusted_set+0x8d/0xa0 fs/ext4/xattr_trusted.c:36
 __vfs_setxattr+0x703/0x790 fs/xattr.c:149
 __vfs_setxattr_noperm+0x27a/0x6f0 fs/xattr.c:180
 vfs_setxattr fs/xattr.c:223 [inline]
 setxattr+0x6ae/0x790 fs/xattr.c:449
 path_setxattr+0x1eb/0x380 fs/xattr.c:468
 SYSC_lsetxattr+0x8d/0xb0 fs/xattr.c:490
 SyS_lsetxattr+0x77/0xa0 fs/xattr.c:486
 entry_SYSCALL_64_fastpath+0x13/0x94
==================================================================

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org # v4.6
2018-01-07 16:22:35 -05:00
Jiang Biao d5dabd6339 fs/mbcache.c: make count_objects() more robust
When running ltp stress test for 7*24 hours, vmscan occasionally emits
the following warning continuously:

  mb_cache_scan+0x0/0x3f0 negative objects to delete
  nr=-9232265467809300450
  ...

Tracing shows the freeable(mb_cache_count returns) is -1, which causes
the continuous accumulation and overflow of total_scan.

This patch makes sure that mb_cache_count() cannot return a negative
value, which makes the mbcache shrinker more robust.

Link: http://lkml.kernel.org/r/1511753419-52328-1-git-send-email-jiang.biao2@zte.com.cn
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zhong.weidong@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29 18:40:43 -08:00
Tahsin Erdogan dec214d00e ext4: xattr inode deduplication
Ext4 now supports xattr values that are up to 64k in size (vfs limit).
Large xattr values are stored in external inodes each one holding a
single value. Once written the data blocks of these inodes are immutable.

The real world use cases are expected to have a lot of value duplication
such as inherited acls etc. To reduce data duplication on disk, this patch
implements a deduplicator that allows sharing of xattr inodes.

The deduplication is based on an in-memory hash lookup that is a best
effort sharing scheme. When a xattr inode is read from disk (i.e.
getxattr() call), its crc32c hash is added to a hash table. Before
creating a new xattr inode for a value being set, the hash table is
checked to see if an existing inode holds an identical value. If such an
inode is found, the ref count on that inode is incremented. On value
removal the ref count is decremented and if it reaches zero the inode is
deleted.

The quota charging for such inodes is manually managed. Every reference
holder is charged the full size as if there was no sharing happening.
This is consistent with how xattr blocks are also charged.

[ Fixed up journal credits calculation to handle inline data and the
  rare case where an shared xattr block can get freed when two thread
  race on breaking the xattr block sharing. --tytso ]

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:44:55 -04:00
Tahsin Erdogan c07dfcb458 mbcache: make mbcache naming more generic
Make names more generic so that mbcache usage is not limited to
block sharing. In a subsequent patch in the series
("ext4: xattr inode deduplication"), we start using the mbcache code
for sharing xattr inodes. With that patch, old mb_cache_entry.e_block
field could be holding either a block number or an inode number.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 10:29:53 -04:00
Eric Biggers b649668c0b mbcache: document that "find" functions only return reusable entries
mb_cache_entry_find_first() and mb_cache_entry_find_next() only return
cache entries with the 'e_reusable' bit set.  This should be documented.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-12-03 15:55:01 -05:00
Eric Biggers 132d4e2d55 mbcache: use consistent type for entry count
mbcache used several different types to represent the number of entries
in the cache.  For consistency within mbcache and with the shrinker API,
always use unsigned long.

This does not change behavior for current mbcache users (ext2 and ext4)
since they limit the entry count to a value which easily fits in an int.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-12-03 15:43:48 -05:00
Eric Biggers 97c7b18a5d mbcache: remove unnecessary module_get/module_put
When mbcache is built as a module, any modules that use it (ext2 and/or
ext4) will depend on its symbols directly, incrementing its reference
count.  Therefore, there is no need to do module_get/module_put.

Also note that since the module_get/module_put were in the mbcache
module itself, executing those lines of code was already dependent on
another reference to the mbcache module being held.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-12-03 15:38:29 -05:00
Eric Biggers 21d0f4fa8e mbcache: don't BUG() if entry cache cannot be allocated
mbcache can be a module that is loaded long after startup, when someone
asks to mount an ext2 or ext4 filesystem.  Therefore it should not BUG()
if kmem_cache_create() fails, but rather just fail the module load.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-12-03 15:28:53 -05:00
Eric Biggers 918b7306ed mbcache: correctly handle 'e_referenced' bit
mbcache entries have an 'e_referenced' bit which users can set with
mb_cache_entry_touch() to indicate that an entry should be given another
pass through the LRU list before the shrinker can delete it.  However,
mb_cache_shrink() actually would, when seeing an e_referenced entry at
the front of the list (the least-recently used end), place it right at
the front of the list again.  The next iteration would then remove the
entry from the list and delete it.  Consequently, e_referenced had
essentially no effect, so ext2/ext4 xattr blocks would sometimes not be
reused as often as expected.

Fix this by making the shrinker move e_referenced entries to the back of
the list rather than the front.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-12-03 15:13:15 -05:00
Chao Yu 8913f343cd mbcache: fix to detect failure of register_shrinker
register_shrinker in mb_cache_create may fail due to no memory. This
patch fixes to do the check of return value of register_shrinker and
handle the error case, otherwise mb_cache_create may return with no
error, but losing the inner shrinker.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-08-31 11:44:36 -04:00
Andreas Gruenbacher 6048c64b26 mbcache: add reusable flag to cache entries
To reduce amount of damage caused by single bad block, we limit number
of inodes sharing an xattr block to 1024. Thus there can be more xattr
blocks with the same contents when there are lots of files with the same
extended attributes. These xattr blocks naturally result in hash
collisions and can form long hash chains and we unnecessarily check each
such block only to find out we cannot use it because it is already
shared by too many inodes.

Add a reusable flag to cache entries which is cleared when a cache entry
has reached its maximum refcount.  Cache entries which are not marked
reusable are skipped by mb_cache_entry_find_{first,next}. This
significantly speeds up mbcache when there are many same xattr blocks.
For example for xattr-bench with 5 values and each process handling
20000 files, the run for 64 processes is 25x faster with this patch.
Even for 8 processes the speedup is almost 3x. We have also verified
that for situations where there is only one xattr block of each kind,
the patch doesn't have a measurable cost.

[JK: Remove handling of setting the same value since it is not needed
anymore, check for races in e_reusable setting, improve changelog,
add measurements]

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 22:44:04 -05:00
Andreas Gruenbacher dc8d5e565f mbcache: get rid of _e_hash_list_head
Get rid of field _e_hash_list_head in cache entries and add bit field
e_referenced instead.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 22:42:05 -05:00
Jan Kara 7a2508e1b6 mbcache2: rename to mbcache
Since old mbcache code is gone, let's rename new code to mbcache since
number 2 is now meaningless. This is just a mechanical replacement.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 22:35:22 -05:00
Jan Kara ecd1e64412 mbcache: remove mbcache
Both ext2 and ext4 are now converted to mbcache2. Remove the old mbcache
code.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 12:21:14 -05:00
T Makphaibulchoke ec7756ae15 fs/mbcache: replace __builtin_log2() with ilog2()
Fix compiler error with some gcc version(s) that do not
support __builtin_log2() by replacing __builtin_log2() with
ilog2().

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
2014-06-25 22:08:29 -04:00
T Makphaibulchoke 9c191f701c ext4: each filesystem creates and uses its own mb_cache
This patch adds new interfaces to create and destory cache,
ext4_xattr_create_cache() and ext4_xattr_destroy_cache(), and remove
the cache creation and destory calls from ex4_init_xattr() and
ext4_exitxattr() in fs/ext4/xattr.c.

fs/ext4/super.c has been changed so that when a filesystem is mounted
a cache is allocated and attched to its ext4_sb_info structure.

fs/mbcache.c has been changed so that only one slab allocator is
allocated and used by all mbcache structures.

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
2014-03-18 19:24:49 -04:00
T Makphaibulchoke 1f3e55fe02 fs/mbcache.c: doucple the locking of local from global data
The patch increases the parallelism of mbcache by using the built-in
lock in the hlist_bl_node to protect the mb_cache's local block and
index hash chains.  The global data mb_cache_lru_list and
mb_cache_list continue to be protected by the global
mb_cache_spinlock.

New block group spinlock, mb_cache_bg_lock is also added to serialize
accesses to mb_cache_entry's local data.

A new member e_refcnt is added to the mb_cache_entry structure to help
preventing an mb_cache_entry from being deallocated by a free while it
is being referenced by either mb_cache_entry_get() or
mb_cache_entry_find().

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-18 19:23:20 -04:00
T Makphaibulchoke 3e037e5211 fs/mbcache.c: change block and index hash chain to hlist_bl_node
This patch changes each mb_cache's both block and index hash chains to
use a hlist_bl_node, which contains a built-in lock.  This is the
first step in decoupling of locks serializing accesses to mb_cache
global data and each mb_cache_entry local data.

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-18 19:19:41 -04:00
Dave Chinner 1ab6c4997e fs: convert fs shrinkers to new scan/count API
Convert the filesystem shrinkers to use the new API, and standardise some
of the behaviours of the shrinkers at the same time.  For example,
nr_to_scan means the number of objects to scan, not the number of objects
to free.

I refactored the CIFS idmap shrinker a little - it really needs to be
broken up into a shrinker per tree and keep an item count with the tree
root so that we don't need to walk the tree every time the shrinker needs
to count the number of objects in the tree (i.e.  all the time under
memory pressure).

[glommer@openvz.org: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are needed mainly due to new code merged in the tree]
[assorted fixes folded in]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:31 -04:00
Glauber Costa 55f841ce93 super: fix calculation of shrinkable objects for small numbers
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.

It works great in situations in which we have many objects (at least more
than 100), because the aproximation errors will be negligible.  But if
this is not the case, specially when total_objects < 100, we may end up
concluding that we have no objects at all (total / 100 = 0, if total <
100).

This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.

Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:29 -04:00
Ying Han 1495f230fa vmscan: change shrinker API by passing shrink_control struct
Change each shrinker's API by consolidating the existing parameters into
shrink_control struct.  This will simplify any further features added w/o
touching each file of shrinker.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix warning]
[kosaki.motohiro@jp.fujitsu.com: fix up new shrinker API]
[akpm@linux-foundation.org: fix xfs warning]
[akpm@linux-foundation.org: update gfs2]
Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:26 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Josh Hunt d96336b05d ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG
When I enable EXT2_XATTR_DEBUG in fs/ext2/xattr.c I get a build error stating
the following:

  CC      fs/ext2/xattr.o
fs/ext2/xattr.c: In function 'ext2_xattr_cache_insert':
fs/ext2/xattr.c:841: error: dereferencing pointer to incomplete type
fs/ext2/xattr.c:846: error: dereferencing pointer to incomplete type
make[2]: *** [fs/ext2/xattr.o] Error 1
make[1]: *** [fs/ext2] Error 2
make: *** [fs] Error 2

These lines reference ext2_xattr_cache->c_entry_count which is defined
in struct mb_cache. struct mb_cache is currently only defined in fs/mbcache.c.
Moving struct mb_cache definition to include/linux/mbcache.h to resolve the
issue.

Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2011-01-10 19:04:08 +01:00
Andreas Gruenbacher 3a48ee8a4a mbcache: Limit the maximum number of cache entries
Limit the maximum number of mb_cache entries depending on the number of
hash buckets: if the only limit to the number of cache entries is the
available memory the hash chains can grow very long, taking a long time
to search.

At least partially solves https://bugzilla.lustre.org/show_bug.cgi?id=22771.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 06:24:41 -04:00
Andreas Gruenbacher e566d48c9b mbcache: fix shrinker function return value
The shrinker function is supposed to return the number of cache
entries after shrinking, not before shrinking.  Fix that.

Based on a patch from Wang Sheng-Hui <crosslonelyover@gmail.com>.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:47 -04:00
Andreas Gruenbacher 2aec7c5232 mbcache: Remove unused features
The mbcache code was written to support a variable number of indexes,
but all the existing users use exactly one index.  Simplify to code to
support only that case.

There are also no users of the cache entry free operation, and none of
the users keep extra data in cache entries.  Remove those features as
well.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:45 -04:00
Dave Chinner 7f8275d0d6 mm: add context argument to shrinker callback
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-07-19 14:56:17 +10:00
Jan Kara 335e92e8a5 vfs: fix possible deadlock in ext2, ext3, ext4 when using xattrs
mb_cache_entry_alloc() was allocating cache entries with GFP_KERNEL.  But
filesystems are calling this function while holding xattr_sem so possible
recursion into the fs violates locking ordering of xattr_sem and transaction
start / i_mutex for ext2-4.  Change mb_cache_entry_alloc() so that filesystems
can specify desired gfp mask and use GFP_NOFS from all of them.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Dave Jones <davej@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-15 19:35:41 -07:00
Ram Gupta f9e83489cb fs: Fix to correct the mbcache entries counter
This patch fixes the c_entry_count counter of the mbcache. Currently
it increments the counter first & allocate the cache entry later. In
case of failure to allocate the entry due to insufficient memory this
counter is still left incremented. This patch fixes this anomaly.

Signed-off-by: Ram Gupta <ram.gupta5@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-25 15:18:29 -07:00
Paul Mundt 20c2df83d2 mm: Remove slab destructors from kmem_cache_create().
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-20 10:11:58 +09:00
Rusty Russell 8e1f936b73 mm: clean up and kernelify shrinker registration
I can never remember what the function to register to receive VM pressure
is called.  I have to trace down from __alloc_pages() to find it.

It's called "set_shrinker()", and it needs Your Help.

1) Don't hide struct shrinker.  It contains no magic.
2) Don't allocate "struct shrinker".  It's not helpful.
3) Call them "register_shrinker" and "unregister_shrinker".
4) Call the function "shrink" not "shrinker".
5) Reduce the 17 lines of waffly comments to 13, but document it properly.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Chinner <dgc@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:00 -07:00
Christoph Lameter e18b890bb0 [PATCH] slab: remove kmem_cache_t
Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:25 -08:00
Josh Triplett 58f555e5f6 [PATCH] mbcache: add lock annotation for __mb_cache_entry_release_unlock()
__mb_cache_entry_release_unlock releases mb_cache_spinlock, so annotate it
accordingly.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:07 -07:00
Alexey Dobriyan 7f927fcc2f [PATCH] Typo fixes
Fix a lot of typos.  Eyeballed by jmc@ in OpenBSD.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:08 -08:00
Paul Jackson 4b6a9316fa [PATCH] cpuset memory spread: slab cache filesystems
Mark file system inode and similar slab caches subject to SLAB_MEM_SPREAD
memory spreading.

If a slab cache is marked SLAB_MEM_SPREAD, then anytime that a task that's
in a cpuset with the 'memory_spread_slab' option enabled goes to allocate
from such a slab cache, the allocations are spread evenly over all the
memory nodes (task->mems_allowed) allowed to that task, instead of favoring
allocation on the node local to the current cpu.

The following inode and similar caches are marked SLAB_MEM_SPREAD:

    file                               cache
    ====                               =====
    fs/adfs/super.c                    adfs_inode_cache
    fs/affs/super.c                    affs_inode_cache
    fs/befs/linuxvfs.c                 befs_inode_cache
    fs/bfs/inode.c                     bfs_inode_cache
    fs/block_dev.c                     bdev_cache
    fs/cifs/cifsfs.c                   cifs_inode_cache
    fs/coda/inode.c                    coda_inode_cache
    fs/dquot.c                         dquot
    fs/efs/super.c                     efs_inode_cache
    fs/ext2/super.c                    ext2_inode_cache
    fs/ext2/xattr.c (fs/mbcache.c)     ext2_xattr
    fs/ext3/super.c                    ext3_inode_cache
    fs/ext3/xattr.c (fs/mbcache.c)     ext3_xattr
    fs/fat/cache.c                     fat_cache
    fs/fat/inode.c                     fat_inode_cache
    fs/freevxfs/vxfs_super.c           vxfs_inode
    fs/hpfs/super.c                    hpfs_inode_cache
    fs/isofs/inode.c                   isofs_inode_cache
    fs/jffs/inode-v23.c                jffs_fm
    fs/jffs2/super.c                   jffs2_i
    fs/jfs/super.c                     jfs_ip
    fs/minix/inode.c                   minix_inode_cache
    fs/ncpfs/inode.c                   ncp_inode_cache
    fs/nfs/direct.c                    nfs_direct_cache
    fs/nfs/inode.c                     nfs_inode_cache
    fs/ntfs/super.c                    ntfs_big_inode_cache_name
    fs/ntfs/super.c                    ntfs_inode_cache
    fs/ocfs2/dlm/dlmfs.c               dlmfs_inode_cache
    fs/ocfs2/super.c                   ocfs2_inode_cache
    fs/proc/inode.c                    proc_inode_cache
    fs/qnx4/inode.c                    qnx4_inode_cache
    fs/reiserfs/super.c                reiser_inode_cache
    fs/romfs/inode.c                   romfs_inode_cache
    fs/smbfs/inode.c                   smb_inode_cache
    fs/sysv/inode.c                    sysv_inode_cache
    fs/udf/super.c                     udf_inode_cache
    fs/ufs/super.c                     ufs_inode_cache
    net/socket.c                       sock_inode_cache
    net/sunrpc/rpc_pipe.c              rpc_inode_cache

The choice of which slab caches to so mark was quite simple.  I marked
those already marked SLAB_RECLAIM_ACCOUNT, except for fs/xfs, dentry_cache,
inode_cache, and buffer_head, which were marked in a previous patch.  Even
though SLAB_RECLAIM_ACCOUNT is for a different purpose, it marks the same
potentially large file system i/o related slab caches as we need for memory
spreading.

Given that the rule now becomes "wherever you would have used a
SLAB_RECLAIM_ACCOUNT slab cache flag before (usually the inode cache), use
the SLAB_MEM_SPREAD flag too", this should be easy enough to maintain.
Future file system writers will just copy one of the existing file system
slab cache setups and tend to get it right without thinking.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:23 -08:00
Arjan van de Ven 858119e159 [PATCH] Unlinline a bunch of other functions
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kb

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:06 -08:00
Jesper Juhl f99d49adf5 [PATCH] kfree cleanup: fs
This is the fs/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in fs/.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:54:06 -08:00
Al Viro 27496a8c67 [PATCH] gfp_t: fs/*
- ->releasepage() annotated (s/int/gfp_t), instances updated
 - missing gfp_t in fs/* added
 - fixed misannotation from the original sweep caught by bitwise checks:
   XFS used __nocast both for gfp_t and for flags used by XFS allocator.
   The latter left with unsigned int __nocast; we might want to add a
   different type for those but for now let's leave them alone.  That,
   BTW, is a case when __nocast use had been actively confusing - it had
   been used in the same code for two different and similar types, with
   no way to catch misuses.  Switch of gfp_t to bitwise had caught that
   immediately...

One tricky bit is left alone to be dealt with later - mapping->flags is
a mix of gfp_t and error indications.  Left alone for now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:47 -07:00