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sctp: convert to genradix
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This also makes sctp_stream_alloc_(out|in) saner, in that they no longer
allocate new flex_arrays/genradixes, they just preallocate more
elements.

This code does however have a suspicious lack of locking.

Link: http://lkml.kernel.org/r/20181217131929.11727-7-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@koverstreet @torvalds
koverstreet authored and torvalds committed Mar 12, 2019
1 parent 94f8f3b commit 2075e50
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Showing 3 changed files with 28 additions and 114 deletions.
15 changes: 8 additions & 7 deletions include/net/sctp/structs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@
#define __sctp_structs_h__

#include <linux/ktime.h>
#include <linux/generic-radix-tree.h>
#include <linux/rhashtable-types.h>
#include <linux/socket.h> /* linux/in.h needs this!! */
#include <linux/in.h> /* We get struct sockaddr_in. */
Expand All @@ -57,7 +58,6 @@
#include <linux/atomic.h> /* This gets us atomic counters. */
#include <linux/skbuff.h> /* We need sk_buff_head. */
#include <linux/workqueue.h> /* We need tq_struct. */
#include <linux/flex_array.h> /* We need flex_array. */
#include <linux/sctp.h> /* We need sctp* header structs. */
#include <net/sctp/auth.h> /* We need auth specific structs */
#include <net/ip.h> /* For inet_skb_parm */
Expand Down Expand Up @@ -1449,8 +1449,9 @@ struct sctp_stream_in {
};

struct sctp_stream {
struct flex_array *out;
struct flex_array *in;
GENRADIX(struct sctp_stream_out) out;
GENRADIX(struct sctp_stream_in) in;

__u16 outcnt;
__u16 incnt;
/* Current stream being sent, if any */
Expand All @@ -1473,17 +1474,17 @@ struct sctp_stream {
};

static inline struct sctp_stream_out *sctp_stream_out(
const struct sctp_stream *stream,
struct sctp_stream *stream,
__u16 sid)
{
return flex_array_get(stream->out, sid);
return genradix_ptr(&stream->out, sid);
}

static inline struct sctp_stream_in *sctp_stream_in(
const struct sctp_stream *stream,
struct sctp_stream *stream,
__u16 sid)
{
return flex_array_get(stream->in, sid);
return genradix_ptr(&stream->in, sid);
}

#define SCTP_SO(s, i) sctp_stream_out((s), (i))
Expand Down
125 changes: 19 additions & 106 deletions net/sctp/stream.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,66 +37,6 @@
#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++;
}
}

static size_t fa_index(struct flex_array *fa, void *elem, size_t count)
{
size_t index = 0;

while (count--) {
if (elem == flex_array_get(fa, index))
break;
index++;
}

return 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.
Expand Down Expand Up @@ -153,53 +93,32 @@ static void sctp_stream_outq_migrate(struct sctp_stream *stream,
static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
gfp_t gfp)
{
struct flex_array *out;
size_t elem_size = sizeof(struct sctp_stream_out);

out = fa_alloc(elem_size, outcnt, gfp);
if (!out)
return -ENOMEM;

if (stream->out) {
fa_copy(out, stream->out, 0, min(outcnt, stream->outcnt));
if (stream->out_curr) {
size_t index = fa_index(stream->out, stream->out_curr,
stream->outcnt);

BUG_ON(index == stream->outcnt);
stream->out_curr = flex_array_get(out, index);
}
fa_free(stream->out);
}
int ret;

if (outcnt > stream->outcnt)
fa_zero(out, stream->outcnt, (outcnt - stream->outcnt));
if (outcnt <= stream->outcnt)
return 0;

stream->out = out;
ret = genradix_prealloc(&stream->out, outcnt, gfp);
if (ret)
return ret;

stream->outcnt = outcnt;
return 0;
}

static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
gfp_t 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) {
fa_copy(in, stream->in, 0, min(incnt, stream->incnt));
fa_free(stream->in);
}
int ret;

if (incnt > stream->incnt)
fa_zero(in, stream->incnt, (incnt - stream->incnt));
if (incnt <= stream->incnt)
return 0;

stream->in = in;
ret = genradix_prealloc(&stream->in, incnt, gfp);
if (ret)
return ret;

stream->incnt = incnt;
return 0;
}

Expand All @@ -226,7 +145,6 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
if (ret)
goto out;

stream->outcnt = outcnt;
for (i = 0; i < stream->outcnt; i++)
SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;

Expand All @@ -238,14 +156,11 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
ret = sctp_stream_alloc_in(stream, incnt, gfp);
if (ret) {
sched->free(stream);
fa_free(stream->out);
stream->out = NULL;
genradix_free(&stream->out);
stream->outcnt = 0;
goto out;
}

stream->incnt = incnt;

out:
return ret;
}
Expand All @@ -270,8 +185,8 @@ void sctp_stream_free(struct sctp_stream *stream)
sched->free(stream);
for (i = 0; i < stream->outcnt; i++)
kfree(SCTP_SO(stream, i)->ext);
fa_free(stream->out);
fa_free(stream->in);
genradix_free(&stream->out);
genradix_free(&stream->in);
}

void sctp_stream_clear(struct sctp_stream *stream)
Expand Down Expand Up @@ -302,8 +217,8 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)

sched->sched_all(stream);

new->out = NULL;
new->in = NULL;
new->out.tree.root = NULL;
new->in.tree.root = NULL;
new->outcnt = 0;
new->incnt = 0;
}
Expand Down Expand Up @@ -555,8 +470,6 @@ int sctp_send_add_streams(struct sctp_association *asoc,
goto out;
}

stream->outcnt = outcnt;

asoc->strreset_outstanding = !!out + !!in;

out:
Expand Down
2 changes: 1 addition & 1 deletion net/sctp/stream_interleave.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -101,7 +101,7 @@ static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)

static bool sctp_validate_data(struct sctp_chunk *chunk)
{
const struct sctp_stream *stream;
struct sctp_stream *stream;
__u16 sid, ssn;

if (chunk->chunk_hdr->type != SCTP_CID_DATA)
Expand Down

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