ceph: check buffer size in ceph_vxattrcb_layout()
If buffer size is zero, return the size of layout vxattr. If buffer
size is not zero, check if it is large enough for layout vxattr.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 2dbd668..28549d5 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -64,32 +64,48 @@
}
static size_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val,
- size_t size)
+ size_t size)
{
int ret;
struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb);
struct ceph_osd_client *osdc = &fsc->client->osdc;
s64 pool = ceph_file_layout_pg_pool(ci->i_layout);
const char *pool_name;
+ char buf[128];
dout("ceph_vxattrcb_layout %p\n", &ci->vfs_inode);
down_read(&osdc->map_sem);
pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
- if (pool_name)
- ret = snprintf(val, size,
- "stripe_unit=%lld stripe_count=%lld object_size=%lld pool=%s",
+ if (pool_name) {
+ size_t len = strlen(pool_name);
+ ret = snprintf(buf, sizeof(buf),
+ "stripe_unit=%lld stripe_count=%lld object_size=%lld pool=",
(unsigned long long)ceph_file_layout_su(ci->i_layout),
(unsigned long long)ceph_file_layout_stripe_count(ci->i_layout),
- (unsigned long long)ceph_file_layout_object_size(ci->i_layout),
- pool_name);
- else
- ret = snprintf(val, size,
+ (unsigned long long)ceph_file_layout_object_size(ci->i_layout));
+ if (!size) {
+ ret += len;
+ } else if (ret + len > size) {
+ ret = -ERANGE;
+ } else {
+ memcpy(val, buf, ret);
+ memcpy(val + ret, pool_name, len);
+ ret += len;
+ }
+ } else {
+ ret = snprintf(buf, sizeof(buf),
"stripe_unit=%lld stripe_count=%lld object_size=%lld pool=%lld",
(unsigned long long)ceph_file_layout_su(ci->i_layout),
(unsigned long long)ceph_file_layout_stripe_count(ci->i_layout),
(unsigned long long)ceph_file_layout_object_size(ci->i_layout),
(unsigned long long)pool);
-
+ if (size) {
+ if (ret <= size)
+ memcpy(val, buf, ret);
+ else
+ ret = -ERANGE;
+ }
+ }
up_read(&osdc->map_sem);
return ret;
}