Commit 54008399 authored by Yan, Zheng's avatar Yan, Zheng Committed by Sage Weil
Browse files

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: default avatarYan, Zheng <zheng.z.yan@intel.com>
parent 18cb95af

fs/ceph/dir.c

+5 −5
Original line number Diff line number Diff line
@@ -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 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) 
		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 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx) 
		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);

fs/ceph/mds_client.c

+51 −15
Original line number Diff line number Diff line
@@ -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 @@ static int parse_reply_info(struct ceph_msg *msg, 


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.

 */

fs/ceph/mds_client.h

+3 −1
Original line number Diff line number Diff line
@@ -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,