From: "Matthew Wilcox (Oracle)" <wi...@infradead.org>
This is a fairly straightforward conversion. The load side could be
converted to RCU by appropriate handling of races between delete and
lookup (eg RCU-freeing the sctp_association). One point to note is
that sctp_assoc_set_id() will now return 1 if the allocation wrapped;
I have converted the callers to check for an error using '< 0' instead
of '!= 0'.
Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
include/net/sctp/sctp.h | 5 ++---
net/sctp/associola.c | 34 +++++++++-------------------------
net/sctp/protocol.c | 6 ------
net/sctp/sm_make_chunk.c | 2 +-
net/sctp/socket.c | 6 +++---
5 files changed, 15 insertions(+), 38 deletions(-)
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 5d60f13d2347..4bcce5d052d1 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -47,7 +47,7 @@
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
-#include <linux/idr.h>
+#include <linux/xarray.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@@ -462,8 +462,7 @@ extern struct proto sctp_prot;
extern struct proto sctpv6_prot;
void sctp_put_port(struct sock *sk);
-extern struct idr sctp_assocs_id;
-extern spinlock_t sctp_assocs_id_lock;
+extern struct xarray sctp_assocs_id;
/* Static inline functions. */
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 5010cce52c93..4d6baecbdb99 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -39,6 +39,9 @@
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
+DEFINE_XARRAY_FLAGS(sctp_assocs_id, XA_FLAGS_ALLOC1 | XA_FLAGS_LOCK_BH);
+static u32 sctp_assocs_next_id;
+
/* Forward declarations for internal functions. */
static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
static void sctp_assoc_bh_rcv(struct work_struct *work);
@@ -412,11 +415,8 @@ static void sctp_association_destroy(struct
sctp_association *asoc)
sctp_endpoint_put(asoc->ep);
sock_put(asoc->base.sk);
- if (asoc->assoc_id != 0) {
- spin_lock_bh(&sctp_assocs_id_lock);
- idr_remove(&sctp_assocs_id, asoc->assoc_id);
- spin_unlock_bh(&sctp_assocs_id_lock);
- }
+ if (asoc->assoc_id != 0)
+ xa_erase_bh(&sctp_assocs_id, asoc->assoc_id);
WARN_ON(atomic_read(&asoc->rmem_alloc));
@@ -1177,7 +1177,7 @@ int sctp_assoc_update(struct sctp_association *asoc,
sctp_stream_update(&asoc->stream, &new->stream);
/* get a new assoc id if we don't have one yet. */
- if (sctp_assoc_set_id(asoc, GFP_ATOMIC))
+ if (sctp_assoc_set_id(asoc, GFP_ATOMIC) < 0)
return -ENOMEM;
}
@@ -1624,29 +1624,13 @@ int sctp_assoc_lookup_laddr(struct sctp_association
*asoc,
/* Set an association id for a given association */
int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
{
- bool preload = gfpflags_allow_blocking(gfp);
- int ret;
-
/* If the id is already assigned, keep it. */
if (asoc->assoc_id)
return 0;
- if (preload)
- idr_preload(gfp);
- spin_lock_bh(&sctp_assocs_id_lock);
- /* 0, 1, 2 are used as SCTP_FUTURE_ASSOC, SCTP_CURRENT_ASSOC and
- * SCTP_ALL_ASSOC, so an available id must be > SCTP_ALL_ASSOC.
- */
- ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, SCTP_ALL_ASSOC + 1, 0,
- GFP_NOWAIT);
- spin_unlock_bh(&sctp_assocs_id_lock);
- if (preload)
- idr_preload_end();
- if (ret < 0)
- return ret;
-
- asoc->assoc_id = (sctp_assoc_t)ret;
- return 0;
+ return xa_alloc_cyclic_bh(&sctp_assocs_id, &asoc->assoc_id, asoc,
+ XA_LIMIT(SCTP_ALL_ASSOC + 1, INT_MAX),
+ &sctp_assocs_next_id, gfp);
}
/* Free the ASCONF queue */
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 2d47adcb4cbe..79ccc786e5c9 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -50,9 +50,6 @@
/* Global data structures. */
struct sctp_globals sctp_globals __read_mostly;
-struct idr sctp_assocs_id;
-DEFINE_SPINLOCK(sctp_assocs_id_lock);
-
static struct sctp_pf *sctp_pf_inet6_specific;
static struct sctp_pf *sctp_pf_inet_specific;
static struct sctp_af *sctp_af_v4_specific;
@@ -1388,9 +1385,6 @@ static __init int sctp_init(void)
sctp_max_instreams = SCTP_DEFAULT_INSTREAMS;
sctp_max_outstreams = SCTP_DEFAULT_OUTSTREAMS;
- /* Initialize handle used for association ids. */
- idr_init(&sctp_assocs_id);
-
limit = nr_free_buffer_pages() / 8;
limit = max(limit, 128UL);
sysctl_sctp_mem[0] = limit / 4 * 3;
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 36bd8a6e82df..f049cfad6cf8 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2443,7 +2443,7 @@ int sctp_process_init(struct sctp_association *asoc,
struct sctp_chunk *chunk,
/* Update frag_point when stream_interleave may get changed. */
sctp_assoc_update_frag_point(asoc);
- if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
+ if (!asoc->temp && sctp_assoc_set_id(asoc, gfp) < 0)
goto clean_up;
/* ADDIP Section 4.1 ASCONF Chunk Procedures
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 12503e16fa96..0df05adfd033 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -236,11 +236,11 @@ struct sctp_association *sctp_id2assoc(struct sock *sk,
sctp_assoc_t id)
if (id <= SCTP_ALL_ASSOC)
return NULL;
- spin_lock_bh(&sctp_assocs_id_lock);
- asoc = (struct sctp_association *)idr_find(&sctp_assocs_id, (int)id);
+ xa_lock_bh(&sctp_assocs_id);
+ asoc = xa_load(&sctp_assocs_id, id);
if (asoc && (asoc->base.sk != sk || asoc->base.dead))
asoc = NULL;
- spin_unlock_bh(&sctp_assocs_id_lock);
+ xa_unlock_bh(&sctp_assocs_id);
return asoc;
}
--
2.23.0.rc1
