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authorStephen Rothwell <sfr@canb.auug.org.au>2017-07-24 14:10:01 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2017-07-24 14:10:01 +1000
commitd1e2a16ff001c5f64e394f072e39f5fecc0012f3 (patch)
treecf0b3a61b5c7d25c8da6a606fe7537f809c22a3c /fs/aio.c
parent999de57661ac015c8fdc962db48d3e5ac2f62646 (diff)
parent4c1d69950da453318c938f8c480388e235c92bb9 (diff)
downloadcoresight-d1e2a16ff001c5f64e394f072e39f5fecc0012f3.tar.gz
Merge remote-tracking branch 'aio/master'
Diffstat (limited to 'fs/aio.c')
-rw-r--r--fs/aio.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/fs/aio.c b/fs/aio.c
index dcad3a66748c..8f0127526299 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -441,10 +441,9 @@ static const struct address_space_operations aio_ctx_aops = {
#endif
};
-static int aio_setup_ring(struct kioctx *ctx)
+static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
{
struct aio_ring *ring;
- unsigned nr_events = ctx->max_reqs;
struct mm_struct *mm = current->mm;
unsigned long size, unused;
int nr_pages;
@@ -707,6 +706,12 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
int err = -ENOMEM;
/*
+ * Store the original nr_events -- what userspace passed to io_setup(),
+ * for counting against the global limit -- before it changes.
+ */
+ unsigned int max_reqs = nr_events;
+
+ /*
* We keep track of the number of available ringbuffer slots, to prevent
* overflow (reqs_available), and we also use percpu counters for this.
*
@@ -724,14 +729,14 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
return ERR_PTR(-EINVAL);
}
- if (!nr_events || (unsigned long)nr_events > (aio_max_nr * 2UL))
+ if (!nr_events || (unsigned long)max_reqs > aio_max_nr)
return ERR_PTR(-EAGAIN);
ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
- ctx->max_reqs = nr_events;
+ ctx->max_reqs = max_reqs;
spin_lock_init(&ctx->ctx_lock);
spin_lock_init(&ctx->completion_lock);
@@ -753,7 +758,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
if (!ctx->cpu)
goto err;
- err = aio_setup_ring(ctx);
+ err = aio_setup_ring(ctx, nr_events);
if (err < 0)
goto err;
@@ -764,8 +769,8 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
/* limit the number of system wide aios */
spin_lock(&aio_nr_lock);
- if (aio_nr + nr_events > (aio_max_nr * 2UL) ||
- aio_nr + nr_events < aio_nr) {
+ if (aio_nr + ctx->max_reqs > aio_max_nr ||
+ aio_nr + ctx->max_reqs < aio_nr) {
spin_unlock(&aio_nr_lock);
err = -EAGAIN;
goto err_ctx;