| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1368494338-7069-6-git-send-email-koverstreet@google.com>
Date: Mon, 13 May 2013 18:18:42 -0700
From: Kent Overstreet <koverstreet@...gle.com>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-aio@...ck.org
Cc: akpm@...ux-foundation.org,
Kent Overstreet <koverstreet@...gle.com>,
Zach Brown <zab@...hat.com>, Felipe Balbi <balbi@...com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Mark Fasheh <mfasheh@...e.com>,
Joel Becker <jlbec@...lplan.org>,
Rusty Russell <rusty@...tcorp.com.au>,
Jens Axboe <axboe@...nel.dk>,
Asai Thambi S P <asamymuthupa@...ron.com>,
Selvan Mani <smani@...ron.com>,
Sam Bradshaw <sbradshaw@...ron.com>,
Jeff Moyer <jmoyer@...hat.com>,
Al Viro <viro@...iv.linux.org.uk>,
Benjamin LaHaise <bcrl@...ck.org>
Subject: [PATCH 05/21] aio: percpu ioctx refcount
This just converts the ioctx refcount to the new generic dynamic percpu
refcount code.
Signed-off-by: Kent Overstreet <koverstreet@...gle.com>
Cc: Zach Brown <zab@...hat.com>
Cc: Felipe Balbi <balbi@...com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Mark Fasheh <mfasheh@...e.com>
Cc: Joel Becker <jlbec@...lplan.org>
Cc: Rusty Russell <rusty@...tcorp.com.au>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Asai Thambi S P <asamymuthupa@...ron.com>
Cc: Selvan Mani <smani@...ron.com>
Cc: Sam Bradshaw <sbradshaw@...ron.com>
Cc: Jeff Moyer <jmoyer@...hat.com>
Cc: Al Viro <viro@...iv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@...ck.org>
Reviewed-by: "Theodore Ts'o" <tytso@....edu>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
---
fs/aio.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index c341cee..93383b0 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -36,6 +36,7 @@
#include <linux/eventfd.h>
#include <linux/blkdev.h>
#include <linux/compat.h>
+#include <linux/percpu-refcount.h>
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
@@ -65,8 +66,7 @@ struct kioctx_cpu {
};
struct kioctx {
- atomic_t users;
- atomic_t dead;
+ struct percpu_ref users;
/* This needs improving */
unsigned long user_id;
@@ -370,7 +370,7 @@ static void free_ioctx(struct kioctx *ctx)
static void put_ioctx(struct kioctx *ctx)
{
- if (unlikely(atomic_dec_and_test(&ctx->users)))
+ if (percpu_ref_put(&ctx->users))
free_ioctx(ctx);
}
@@ -411,8 +411,13 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
ctx->max_reqs = nr_events;
- atomic_set(&ctx->users, 2);
- atomic_set(&ctx->dead, 0);
+ if (percpu_ref_init(&ctx->users))
+ goto out_freectx;
+
+ rcu_read_lock();
+ percpu_ref_get(&ctx->users);
+ rcu_read_unlock();
+
spin_lock_init(&ctx->ctx_lock);
spin_lock_init(&ctx->completion_lock);
mutex_init(&ctx->ring_lock);
@@ -422,7 +427,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
ctx->cpu = alloc_percpu(struct kioctx_cpu);
if (!ctx->cpu)
- goto out_freectx;
+ goto out_freeref;
if (aio_setup_ring(ctx) < 0)
goto out_freepcpu;
@@ -455,6 +460,8 @@ out_cleanup:
aio_free_ring(ctx);
out_freepcpu:
free_percpu(ctx->cpu);
+out_freeref:
+ free_percpu(ctx->users.pcpu_count);
out_freectx:
kmem_cache_free(kioctx_cachep, ctx);
pr_debug("error allocating ioctx %d\n", err);
@@ -484,7 +491,7 @@ static void kill_ioctx_rcu(struct rcu_head *head)
*/
static void kill_ioctx(struct kioctx *ctx)
{
- if (!atomic_xchg(&ctx->dead, 1)) {
+ if (percpu_ref_kill(&ctx->users)) {
hlist_del_rcu(&ctx->list);
/* Between hlist_del_rcu() and dropping the initial ref */
synchronize_rcu();
@@ -530,12 +537,6 @@ void exit_aio(struct mm_struct *mm)
struct hlist_node *n;
hlist_for_each_entry_safe(ctx, n, &mm->ioctx_list, list) {
- if (1 != atomic_read(&ctx->users))
- printk(KERN_DEBUG
- "exit_aio:ioctx still alive: %d %d %d\n",
- atomic_read(&ctx->users),
- atomic_read(&ctx->dead),
- atomic_read(&ctx->reqs_available));
/*
* We don't need to bother with munmap() here -
* exit_mmap(mm) is coming and it'll unmap everything.
@@ -546,7 +547,7 @@ void exit_aio(struct mm_struct *mm)
*/
ctx->mmap_size = 0;
- if (!atomic_xchg(&ctx->dead, 1)) {
+ if (percpu_ref_kill(&ctx->users)) {
hlist_del_rcu(&ctx->list);
call_rcu(&ctx->rcu_head, kill_ioctx_rcu);
}
@@ -657,7 +658,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
hlist_for_each_entry_rcu(ctx, &mm->ioctx_list, list) {
if (ctx->user_id == ctx_id) {
- atomic_inc(&ctx->users);
+ percpu_ref_get(&ctx->users);
ret = ctx;
break;
}
@@ -870,7 +871,7 @@ static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
if (ret > 0)
*i += ret;
- if (unlikely(atomic_read(&ctx->dead)))
+ if (unlikely(percpu_ref_dead(&ctx->users)))
ret = -EINVAL;
if (!*i)
--
1.8.2.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists