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-rw-r--r--fs/aio.c31
-rw-r--r--include/linux/aio.h5
-rw-r--r--kernel/sysctl.c4
3 files changed, 26 insertions, 14 deletions
diff --git a/fs/aio.c b/fs/aio.c
index edfca5b75535..20bb919eb195 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -42,8 +42,9 @@
#endif
/*------ sysctl variables----*/
-atomic_t aio_nr = ATOMIC_INIT(0); /* current system wide number of aio requests */
-unsigned aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
+static DEFINE_SPINLOCK(aio_nr_lock);
+unsigned long aio_nr; /* current system wide number of aio requests */
+unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
/*----end sysctl variables---*/
static kmem_cache_t *kiocb_cachep;
@@ -208,7 +209,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
return ERR_PTR(-EINVAL);
}
- if (nr_events > aio_max_nr)
+ if ((unsigned long)nr_events > aio_max_nr)
return ERR_PTR(-EAGAIN);
ctx = kmem_cache_alloc(kioctx_cachep, GFP_KERNEL);
@@ -233,8 +234,14 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
goto out_freectx;
/* limit the number of system wide aios */
- atomic_add(ctx->max_reqs, &aio_nr); /* undone by __put_ioctx */
- if (unlikely(atomic_read(&aio_nr) > aio_max_nr))
+ spin_lock(&aio_nr_lock);
+ if (aio_nr + ctx->max_reqs > aio_max_nr ||
+ aio_nr + ctx->max_reqs < aio_nr)
+ ctx->max_reqs = 0;
+ else
+ aio_nr += ctx->max_reqs;
+ spin_unlock(&aio_nr_lock);
+ if (ctx->max_reqs == 0)
goto out_cleanup;
/* now link into global list. kludge. FIXME */
@@ -248,8 +255,6 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
return ctx;
out_cleanup:
- atomic_sub(ctx->max_reqs, &aio_nr);
- ctx->max_reqs = 0; /* prevent __put_ioctx from sub'ing aio_nr */
__put_ioctx(ctx);
return ERR_PTR(-EAGAIN);
@@ -374,7 +379,12 @@ void fastcall __put_ioctx(struct kioctx *ctx)
pr_debug("__put_ioctx: freeing %p\n", ctx);
kmem_cache_free(kioctx_cachep, ctx);
- atomic_sub(nr_events, &aio_nr);
+ if (nr_events) {
+ spin_lock(&aio_nr_lock);
+ BUG_ON(aio_nr - nr_events > aio_nr);
+ aio_nr -= nr_events;
+ spin_unlock(&aio_nr_lock);
+ }
}
/* aio_get_req
@@ -1258,8 +1268,9 @@ asmlinkage long sys_io_setup(unsigned nr_events, aio_context_t __user *ctxp)
goto out;
ret = -EINVAL;
- if (unlikely(ctx || (int)nr_events <= 0)) {
- pr_debug("EINVAL: io_setup: ctx or nr_events > max\n");
+ if (unlikely(ctx || nr_events == 0)) {
+ pr_debug("EINVAL: io_setup: ctx %lu nr_events %u\n",
+ ctx, nr_events);
goto out;
}
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 0decf66117c1..403d71dcb7c8 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -183,6 +183,7 @@ struct kioctx {
struct list_head active_reqs; /* used for cancellation */
struct list_head run_list; /* used for kicked reqs */
+ /* sys_io_setup currently limits this to an unsigned int */
unsigned max_reqs;
struct aio_ring_info ring_info;
@@ -234,7 +235,7 @@ static inline struct kiocb *list_kiocb(struct list_head *h)
}
/* for sysctl: */
-extern atomic_t aio_nr;
-extern unsigned aio_max_nr;
+extern unsigned long aio_nr;
+extern unsigned long aio_max_nr;
#endif /* __LINUX__AIO_H */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 8e56e2495542..e1351200ce85 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -952,7 +952,7 @@ static ctl_table fs_table[] = {
.data = &aio_nr,
.maxlen = sizeof(aio_nr),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_doulongvec_minmax,
},
{
.ctl_name = FS_AIO_MAX_NR,
@@ -960,7 +960,7 @@ static ctl_table fs_table[] = {
.data = &aio_max_nr,
.maxlen = sizeof(aio_max_nr),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_doulongvec_minmax,
},
#ifdef CONFIG_INOTIFY
{

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