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authorKonstantin Khorenko <khorenko@virtuozzo.com>2018-08-10 20:11:43 +0300
committerDavid S. Miller <davem@davemloft.net>2018-08-11 22:25:15 +0300
commit0d493b4d0be352b5e361e4fa0bc3efe952d8b10e (patch)
treedeb3bba890d034e4bbf323e99060f7c5fe934e6e /net/sctp
parent05364ca03cfd419caecb292fede20eb39667eaae (diff)
downloadlinux-0d493b4d0be352b5e361e4fa0bc3efe952d8b10e.tar.xz
net/sctp: Replace in/out stream arrays with flex_array
This path replaces physically contiguous memory arrays allocated using kmalloc_array() with flexible arrays. This enables to avoid memory allocation failures on the systems under a memory stress. Signed-off-by: Oleg Babin <obabin@virtuozzo.com> Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
-rw-r--r--net/sctp/stream.c88
1 files changed, 66 insertions, 22 deletions
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 7ca6fe4e7882..ffb940d3b57c 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -37,6 +37,53 @@
#include <net/sctp/sm.h>
#include <net/sctp/stream_sched.h>
+static struct flex_array *fa_alloc(size_t elem_size, size_t elem_count,
+ gfp_t gfp)
+{
+ struct flex_array *result;
+ int err;
+
+ result = flex_array_alloc(elem_size, elem_count, gfp);
+ if (result) {
+ err = flex_array_prealloc(result, 0, elem_count, gfp);
+ if (err) {
+ flex_array_free(result);
+ result = NULL;
+ }
+ }
+
+ return result;
+}
+
+static void fa_free(struct flex_array *fa)
+{
+ if (fa)
+ flex_array_free(fa);
+}
+
+static void fa_copy(struct flex_array *fa, struct flex_array *from,
+ size_t index, size_t count)
+{
+ void *elem;
+
+ while (count--) {
+ elem = flex_array_get(from, index);
+ flex_array_put(fa, index, elem, 0);
+ index++;
+ }
+}
+
+static void fa_zero(struct flex_array *fa, size_t index, size_t count)
+{
+ void *elem;
+
+ while (count--) {
+ elem = flex_array_get(fa, index);
+ memset(elem, 0, fa->element_size);
+ index++;
+ }
+}
+
/* Migrates chunks from stream queues to new stream queues if needed,
* but not across associations. Also, removes those chunks to streams
* higher than the new max.
@@ -78,34 +125,33 @@ static void sctp_stream_outq_migrate(struct sctp_stream *stream,
* sctp_stream_update will swap ->out pointers.
*/
for (i = 0; i < outcnt; i++) {
- kfree(new->out[i].ext);
- new->out[i].ext = stream->out[i].ext;
- stream->out[i].ext = NULL;
+ kfree(SCTP_SO(new, i)->ext);
+ SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
+ SCTP_SO(stream, i)->ext = NULL;
}
}
for (i = outcnt; i < stream->outcnt; i++)
- kfree(stream->out[i].ext);
+ kfree(SCTP_SO(stream, i)->ext);
}
static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
gfp_t gfp)
{
- struct sctp_stream_out *out;
+ struct flex_array *out;
+ size_t elem_size = sizeof(struct sctp_stream_out);
- out = kmalloc_array(outcnt, sizeof(*out), gfp);
+ out = fa_alloc(elem_size, outcnt, gfp);
if (!out)
return -ENOMEM;
if (stream->out) {
- memcpy(out, stream->out, min(outcnt, stream->outcnt) *
- sizeof(*out));
- kfree(stream->out);
+ fa_copy(out, stream->out, 0, min(outcnt, stream->outcnt));
+ fa_free(stream->out);
}
if (outcnt > stream->outcnt)
- memset(out + stream->outcnt, 0,
- (outcnt - stream->outcnt) * sizeof(*out));
+ fa_zero(out, stream->outcnt, (outcnt - stream->outcnt));
stream->out = out;
@@ -115,22 +161,20 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
gfp_t gfp)
{
- struct sctp_stream_in *in;
-
- in = kmalloc_array(incnt, sizeof(*stream->in), gfp);
+ struct flex_array *in;
+ size_t elem_size = sizeof(struct sctp_stream_in);
+ in = fa_alloc(elem_size, incnt, gfp);
if (!in)
return -ENOMEM;
if (stream->in) {
- memcpy(in, stream->in, min(incnt, stream->incnt) *
- sizeof(*in));
- kfree(stream->in);
+ fa_copy(in, stream->in, 0, min(incnt, stream->incnt));
+ fa_free(stream->in);
}
if (incnt > stream->incnt)
- memset(in + stream->incnt, 0,
- (incnt - stream->incnt) * sizeof(*in));
+ fa_zero(in, stream->incnt, (incnt - stream->incnt));
stream->in = in;
@@ -174,7 +218,7 @@ in:
ret = sctp_stream_alloc_in(stream, incnt, gfp);
if (ret) {
sched->free(stream);
- kfree(stream->out);
+ fa_free(stream->out);
stream->out = NULL;
stream->outcnt = 0;
goto out;
@@ -206,8 +250,8 @@ void sctp_stream_free(struct sctp_stream *stream)
sched->free(stream);
for (i = 0; i < stream->outcnt; i++)
kfree(SCTP_SO(stream, i)->ext);
- kfree(stream->out);
- kfree(stream->in);
+ fa_free(stream->out);
+ fa_free(stream->in);
}
void sctp_stream_clear(struct sctp_stream *stream)