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ceph: preallocate buffer for readdir reply

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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>
This commit is contained in:
Yan, Zheng
2014-03-29 13:41:15 +08:00
committed by Sage Weil
parent 18cb95af2d
commit 54008399dc
3 changed files with 59 additions and 21 deletions
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66
fs/ceph/mds_client.c
View File

@@ -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 @@ static int parse_reply_info_dir(void **p, void *end,
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 @@ out_bad:
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 @@ void ceph_mdsc_release_request(struct kref *kref)
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 @@ static void discard_cap_releases(struct ceph_mds_client *mdsc,
* 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.
*/