sctp: convert to genradix

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>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 58e4b23..140fd83 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -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. */
@@ -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 */
@@ -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 */
@@ -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))

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 3b47457..b6bb68a 100644 (file)
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -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.
@@ -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;
 }
 
@@ -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;
 
@@ -238,14 +156,11 @@ in:
        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;
 }
@@ -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)
@@ -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;
 }
@@ -555,8 +470,6 @@ int sctp_send_add_streams(struct sctp_association *asoc,
                goto out;
        }
 
-       stream->outcnt = outcnt;
-
        asoc->strreset_outstanding = !!out + !!in;
 
 out:

diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c
index a6bf215..102c6fe 100644 (file)
--- a/net/sctp/stream_interleave.c
+++ b/net/sctp/stream_interleave.c
@@ -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)