ceph: preallocate buffer for readdir reply
Preallocate buffer for readdir reply. Limit number of entries in
readdir reply according to the buffer size.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 77640ada4..19fbfc4 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/wait.h>
#include <linux/slab.h>
+#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
@@ -165,21 +166,18 @@
if (num == 0)
goto done;
- /* alloc large array */
- info->dir_nr = num;
- info->dir_in = kcalloc(num, sizeof(*info->dir_in) +
- sizeof(*info->dir_dname) +
- sizeof(*info->dir_dname_len) +
- sizeof(*info->dir_dlease),
- GFP_NOFS);
- if (info->dir_in == NULL) {
- err = -ENOMEM;
- goto out_bad;
- }
+ BUG_ON(!info->dir_in);
info->dir_dname = (void *)(info->dir_in + num);
info->dir_dname_len = (void *)(info->dir_dname + num);
info->dir_dlease = (void *)(info->dir_dname_len + num);
+ if ((unsigned long)(info->dir_dlease + num) >
+ (unsigned long)info->dir_in + info->dir_buf_size) {
+ pr_err("dir contents are larger than expected\n");
+ WARN_ON(1);
+ goto bad;
+ }
+ info->dir_nr = num;
while (num) {
/* dentry */
ceph_decode_need(p, end, sizeof(u32)*2, bad);
@@ -327,7 +325,9 @@
static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
{
- kfree(info->dir_in);
+ if (!info->dir_in)
+ return;
+ free_pages((unsigned long)info->dir_in, get_order(info->dir_buf_size));
}
@@ -512,12 +512,11 @@
struct ceph_mds_request *req = container_of(kref,
struct ceph_mds_request,
r_kref);
+ destroy_reply_info(&req->r_reply_info);
if (req->r_request)
ceph_msg_put(req->r_request);
- if (req->r_reply) {
+ if (req->r_reply)
ceph_msg_put(req->r_reply);
- destroy_reply_info(&req->r_reply_info);
- }
if (req->r_inode) {
ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
iput(req->r_inode);
@@ -1496,6 +1495,43 @@
* requests
*/
+int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
+ struct inode *dir)
+{
+ struct ceph_inode_info *ci = ceph_inode(dir);
+ struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
+ struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
+ size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
+ sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
+ int order, num_entries;
+
+ spin_lock(&ci->i_ceph_lock);
+ num_entries = ci->i_files + ci->i_subdirs;
+ spin_unlock(&ci->i_ceph_lock);
+ num_entries = max(num_entries, 1);
+ num_entries = min(num_entries, opt->max_readdir);
+
+ order = get_order(size * num_entries);
+ while (order >= 0) {
+ rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
+ order);
+ if (rinfo->dir_in)
+ break;
+ order--;
+ }
+ if (!rinfo->dir_in)
+ return -ENOMEM;
+
+ num_entries = (PAGE_SIZE << order) / size;
+ num_entries = min(num_entries, opt->max_readdir);
+
+ rinfo->dir_buf_size = PAGE_SIZE << order;
+ req->r_num_caps = num_entries + 1;
+ req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
+ req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
+ return 0;
+}
+
/*
* Create an mds request.
*/
