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>
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

View File

@ -252,8 +252,6 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
int err;
u32 ftype;
struct ceph_mds_reply_info_parsed *rinfo;
const int max_entries = fsc->mount_options->max_readdir;
const int max_bytes = fsc->mount_options->max_readdir_bytes;
dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
if (fi->flags & CEPH_F_ATEND)
@ -327,6 +325,11 @@ more:
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req))
return PTR_ERR(req);
err = ceph_alloc_readdir_reply_buffer(req, inode);
if (err) {
ceph_mdsc_put_request(req);
return err;
}
req->r_inode = inode;
ihold(inode);
req->r_dentry = dget(file->f_dentry);
@ -337,9 +340,6 @@ more:
req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
req->r_readdir_offset = fi->next_offset;
req->r_args.readdir.frag = cpu_to_le32(frag);
req->r_args.readdir.max_entries = cpu_to_le32(max_entries);
req->r_args.readdir.max_bytes = cpu_to_le32(max_bytes);
req->r_num_caps = max_entries + 1;
err = ceph_mdsc_do_request(mdsc, NULL, req);
if (err < 0) {
ceph_mdsc_put_request(req);

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.
*/

View File

@ -67,6 +67,7 @@ struct ceph_mds_reply_info_parsed {
/* for readdir results */
struct {
struct ceph_mds_reply_dirfrag *dir_dir;
size_t dir_buf_size;
int dir_nr;
char **dir_dname;
u32 *dir_dname_len;
@ -346,7 +347,8 @@ extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
struct dentry *dn);
extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
struct inode *dir);
extern struct ceph_mds_request *
ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,