ceph: use pagelist to present MDS request data
Current code uses page array to present MDS request data. Pages in the
array are allocated/freed by caller of ceph_mdsc_do_request(). If request
is interrupted, the pages can be freed while they are still being used by
the request message.
The fix is use pagelist to present MDS request data. Pagelist is
reference counted.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b4430ce..f8f774e 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -543,6 +543,8 @@
}
kfree(req->r_path1);
kfree(req->r_path2);
+ if (req->r_pagelist)
+ ceph_pagelist_release(req->r_pagelist);
put_request_session(req);
ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
kfree(req);
@@ -1916,13 +1918,15 @@
msg->front.iov_len = p - msg->front.iov_base;
msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
- if (req->r_data_len) {
- /* outbound data set only by ceph_sync_setxattr() */
- BUG_ON(!req->r_pages);
- ceph_msg_data_add_pages(msg, req->r_pages, req->r_data_len, 0);
+ if (req->r_pagelist) {
+ struct ceph_pagelist *pagelist = req->r_pagelist;
+ atomic_inc(&pagelist->refcnt);
+ ceph_msg_data_add_pagelist(msg, pagelist);
+ msg->hdr.data_len = cpu_to_le32(pagelist->length);
+ } else {
+ msg->hdr.data_len = 0;
}
- msg->hdr.data_len = cpu_to_le32(req->r_data_len);
msg->hdr.data_off = cpu_to_le16(0);
out_free2:
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index e00737c..23015f7 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -202,9 +202,7 @@
bool r_direct_is_hash; /* true if r_direct_hash is valid */
/* data payload is used for xattr ops */
- struct page **r_pages;
- int r_num_pages;
- int r_data_len;
+ struct ceph_pagelist *r_pagelist;
/* what caps shall we drop? */
int r_inode_drop, r_inode_unless;
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 19da502..678b0d2 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1,4 +1,5 @@
#include <linux/ceph/ceph_debug.h>
+#include <linux/ceph/pagelist.h>
#include "super.h"
#include "mds_client.h"
@@ -850,35 +851,25 @@
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_mds_request *req;
struct ceph_mds_client *mdsc = fsc->mdsc;
+ struct ceph_pagelist *pagelist = NULL;
int err;
- int i, nr_pages;
- struct page **pages = NULL;
- void *kaddr;
- /* copy value into some pages */
- nr_pages = calc_pages_for(0, size);
- if (nr_pages) {
- pages = kmalloc(sizeof(pages[0])*nr_pages, GFP_NOFS);
- if (!pages)
+ if (value) {
+ /* copy value into pagelist */
+ pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
+ if (!pagelist)
return -ENOMEM;
- err = -ENOMEM;
- for (i = 0; i < nr_pages; i++) {
- pages[i] = __page_cache_alloc(GFP_NOFS);
- if (!pages[i]) {
- nr_pages = i;
- goto out;
- }
- kaddr = kmap(pages[i]);
- memcpy(kaddr, value + i*PAGE_CACHE_SIZE,
- min(PAGE_CACHE_SIZE, size-i*PAGE_CACHE_SIZE));
- }
+
+ ceph_pagelist_init(pagelist);
+ err = ceph_pagelist_append(pagelist, value, size);
+ if (err)
+ goto out;
+ } else {
+ flags |= CEPH_XATTR_REMOVE;
}
dout("setxattr value=%.*s\n", (int)size, value);
- if (!value)
- flags |= CEPH_XATTR_REMOVE;
-
/* do request */
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETXATTR,
USE_AUTH_MDS);
@@ -893,9 +884,8 @@
req->r_args.setxattr.flags = cpu_to_le32(flags);
req->r_path2 = kstrdup(name, GFP_NOFS);
- req->r_pages = pages;
- req->r_num_pages = nr_pages;
- req->r_data_len = size;
+ req->r_pagelist = pagelist;
+ pagelist = NULL;
dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
err = ceph_mdsc_do_request(mdsc, NULL, req);
@@ -903,11 +893,8 @@
dout("xattr.ver (after): %lld\n", ci->i_xattrs.version);
out:
- if (pages) {
- for (i = 0; i < nr_pages; i++)
- __free_page(pages[i]);
- kfree(pages);
- }
+ if (pagelist)
+ ceph_pagelist_release(pagelist);
return err;
}