The patch titled
Subject: dcache: fix indirectly reclaimable memory accounting
has been added to the -mm tree. Its filename is
dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
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there every 3-4 working days
------------------------------------------------------
From: Roman Gushchin <guro@xxxxxx>
Subject: dcache: fix indirectly reclaimable memory accounting
External names can be released using kfree_rcu() from
release_dentry_name_snapshot() and copy_name(), and it will lead to the
imbalance in the indirectly reclaimable memory accounting.
Fix this by introducing __d_free_external_name() and call it from all
release paths.
Link: http://lkml.kernel.org/r/20180313125701.7955-1-guro@xxxxxx
Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dcache.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff -puN fs/dcache.c~dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2 fs/dcache.c
--- a/fs/dcache.c~dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2
+++ a/fs/dcache.c
@@ -266,16 +266,24 @@ static void __d_free(struct rcu_head *he
kmem_cache_free(dentry_cache, dentry);
}
-static void __d_free_external(struct rcu_head *head)
+static void __d_free_external_name(struct rcu_head *head)
{
- struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
- struct external_name *name = external_name(dentry);
+ struct external_name *name = container_of(head, struct external_name,
+ u.head);
mod_node_page_state(page_pgdat(virt_to_page(name)),
NR_INDIRECTLY_RECLAIMABLE_BYTES,
-ksize(name));
kfree(name);
+}
+
+static void __d_free_external(struct rcu_head *head)
+{
+ struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
+
+ __d_free_external_name(&external_name(dentry)->u.head);
+
kmem_cache_free(dentry_cache, dentry);
}
@@ -307,7 +315,7 @@ void release_dentry_name_snapshot(struct
struct external_name *p;
p = container_of(name->name, struct external_name, name[0]);
if (unlikely(atomic_dec_and_test(&p->u.count)))
- kfree_rcu(p, u.head);
+ call_rcu(&p->u.head, __d_free_external_name);
}
}
EXPORT_SYMBOL(release_dentry_name_snapshot);
@@ -2769,7 +2777,7 @@ static void copy_name(struct dentry *den
dentry->d_name.hash_len = target->d_name.hash_len;
}
if (old_name && likely(atomic_dec_and_test(&old_name->u.count)))
- kfree_rcu(old_name, u.head);
+ call_rcu(&old_name->u.head, __d_free_external_name);
}
static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target)
_
Patches currently in -mm which might be from guro@xxxxxx are
mm-introduce-nr_indirectly_reclaimable_bytes.patch
mm-treat-indirectly-reclaimable-memory-as-available-in-memavailable.patch
dcache-account-external-names-as-indirectly-reclaimable-memory.patch
dcache-account-external-names-as-indirectly-reclaimable-memory-fix.patch
dcache-account-external-names-as-indirectly-reclaimable-memory-fix-2.patch
mm-treat-indirectly-reclaimable-memory-as-free-in-overcommit-logic.patch
mm-oom-refactor-the-oom_kill_process-function.patch
mm-implement-mem_cgroup_scan_tasks-for-the-root-memory-cgroup.patch
mm-oom-cgroup-aware-oom-killer.patch
mm-oom-introduce-memoryoom_group.patch
mm-oom-introduce-memoryoom_group-fix.patch
mm-oom-add-cgroup-v2-mount-option-for-cgroup-aware-oom-killer.patch
mm-oom-docs-describe-the-cgroup-aware-oom-killer.patch
mm-oom-docs-describe-the-cgroup-aware-oom-killer-fix.patch
cgroup-list-groupoom-in-cgroup-features.patch
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