From 54008399dc0ce511a07b87f1af3d1f5c791982a4 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Sat, 29 Mar 2014 13:41:15 +0800 Subject: [PATCH] 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 --- fs/ceph/dir.c | 10 +++---- fs/ceph/mds_client.c | 66 ++++++++++++++++++++++++++++++++++---------- fs/ceph/mds_client.h | 4 ++- 3 files changed, 59 insertions(+), 21 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index ff2864a36a1c..46cd092cb013 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -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); diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 77640ada487a..19fbfc496137 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -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. */ diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index 68288917c737..e90cfccf93bd 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -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, -- 2.20.1