[PATCH 3/3] 9p: Add mempools for RPCs

Kent Overstreet
2022-07-04T01:43:02Z

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
---
include/net/9p/9p.h | 6 ++++-
include/net/9p/client.h | 5 +++-
net/9p/client.c | 58 ++++++++++++++++++++++++++++++-----------
net/9p/trans_rdma.c | 2 +-
4 files changed, 53 insertions(+), 18 deletions(-)

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 24a509f559..c0d59b53c1 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -539,12 +539,16 @@ struct p9_rstatfs {
struct p9_fcall {
u32 size;
u8 id;
+ enum p9_fcall_alloc {
+ P9_FCALL_KMEM_CACHE,
+ P9_FCALL_KMALLOC,
+ P9_FCALL_MEMPOOL,
+ } allocated;
u16 tag;

size_t offset;
size_t capacity;

- struct kmem_cache *cache;
u8 *sdata;
};

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index cb78e0e333..6517ca36bf 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -9,6 +9,7 @@
#ifndef NET_9P_CLIENT_H
#define NET_9P_CLIENT_H

+#include <linux/mempool.h>
#include <linux/utsname.h>
#include <linux/idr.h>

@@ -106,6 +107,7 @@ struct p9_client {
enum p9_trans_status status;
void *trans;
struct kmem_cache *fcall_cache;
+ mempool_t pools[2];

union {
struct {
@@ -222,7 +224,8 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
kgid_t gid, struct p9_qid *qid);
int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
-void p9_fcall_fini(struct p9_fcall *fc);
+void p9_fcall_fini(struct p9_client *c, struct p9_fcall *fc,
+ int fc_idx);
struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);

static inline void p9_req_get(struct p9_req_t *r)
diff --git a/net/9p/client.c b/net/9p/client.c
index a36a40137c..82061c49cb 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -219,22 +219,34 @@ static int parse_opts(char *opts, struct p9_client *clnt)
}

static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
- int alloc_msize)
+ int fc_idx, unsigned alloc_msize)
{
+ WARN(alloc_msize > c->msize, "alloc_mize %u client msize %u",
+ alloc_msize, c->msize);
+
if (likely(c->fcall_cache) && alloc_msize == c->msize) {
fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
- fc->cache = c->fcall_cache;
+ fc->allocated = P9_FCALL_KMEM_CACHE;
} else {
fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
- fc->cache = NULL;
+ fc->allocated = P9_FCALL_KMALLOC;
}
- if (!fc->sdata)
+
+ if (!fc->sdata >> alloc_msize > c->msize)
return -ENOMEM;
+
+ if (!fc->sdata) {
+ fc->sdata = mempool_alloc(&c->pools[fc_idx], GFP_NOFS);
+ fc->allocated = P9_FCALL_MEMPOOL;
+ alloc_msize = c->msize;
+ }
+
fc->capacity = alloc_msize;
return 0;
}

-void p9_fcall_fini(struct p9_fcall *fc)
+void p9_fcall_fini(struct p9_client *c, struct p9_fcall *fc,
+ int fc_idx)
{
/* sdata can be NULL for interrupted requests in trans_rdma,
* and kmem_cache_free does not do NULL-check for us
@@ -242,10 +254,17 @@ void p9_fcall_fini(struct p9_fcall *fc)
if (unlikely(!fc->sdata))
return;

- if (fc->cache)
- kmem_cache_free(fc->cache, fc->sdata);
- else
+ switch (fc->allocated) {
+ case P9_FCALL_KMEM_CACHE:
+ kmem_cache_free(c->fcall_cache, fc->sdata);
+ break;
+ case P9_FCALL_KMALLOC:
kfree(fc->sdata);
+ break;
+ case P9_FCALL_MEMPOOL:
+ mempool_free(fc->sdata, &c->pools[fc_idx]);
+ break;
+ }
}
EXPORT_SYMBOL(p9_fcall_fini);

@@ -270,9 +289,9 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
if (!req)
return ERR_PTR(-ENOMEM);

- if (p9_fcall_init(c, &req->tc, alloc_msize))
+ if (p9_fcall_init(c, &req->tc, 0, alloc_msize))
goto free_req;
- if (p9_fcall_init(c, &req->rc, alloc_msize))
+ if (p9_fcall_init(c, &req->rc, 1, alloc_msize))
goto free;

p9pdu_reset(&req->tc);
@@ -310,8 +329,8 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
return req;

free:
- p9_fcall_fini(&req->tc);
- p9_fcall_fini(&req->rc);
+ p9_fcall_fini(c, &req->tc, 0);
+ p9_fcall_fini(c, &req->rc, 1);
free_req:
kmem_cache_free(p9_req_cache, req);
return ERR_PTR(-ENOMEM);
@@ -373,8 +392,8 @@ static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
int p9_req_put(struct p9_client *c, struct p9_req_t *r)
{
if (refcount_dec_and_test(&r->refcount)) {
- p9_fcall_fini(&r->tc);
- p9_fcall_fini(&r->rc);
+ p9_fcall_fini(c, &r->tc, 0);
+ p9_fcall_fini(c, &r->rc, 1);
kmem_cache_free(p9_req_cache, r);
return 1;
}
@@ -999,7 +1018,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
char *client_id;

err = 0;
- clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
+ clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
if (!clnt)
return ERR_PTR(-ENOMEM);

@@ -1063,6 +1082,11 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
clnt->msize - (P9_HDRSZ + 4),
NULL);

+ err = mempool_init_kmalloc_pool(&clnt->pools[0], 4, clnt->msize) ?:
+ mempool_init_kmalloc_pool(&clnt->pools[1], 4, clnt->msize);
+ if (err)
+ goto close_trans;
+
return clnt;

close_trans:
@@ -1070,6 +1094,8 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
put_trans:
v9fs_put_trans(clnt->trans_mod);
free_client:
+ mempool_exit(&clnt->pools[1]);
+ mempool_exit(&clnt->pools[0]);
kfree(clnt);
return ERR_PTR(err);
}
@@ -1094,6 +1120,8 @@ void p9_client_destroy(struct p9_client *clnt)

p9_tag_cleanup(clnt);

+ mempool_exit(&clnt->pools[1]);
+ mempool_exit(&clnt->pools[0]);
kmem_cache_destroy(clnt->fcall_cache);
kfree(clnt);
}
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index d817d37452..99d878d70d 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -431,7 +431,7 @@ static int rdma_request(struct p9_client *client, struct p9_req_t *req)
if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
/* Got one! */
- p9_fcall_fini(&req->rc);
+ p9_fcall_fini(client, &req->rc, 1);
req->rc.sdata = NULL;
goto dont_need_post_recv;
} else {
--
2.36.1