ceph: fetch inline data when getting Fcr cap refs
we can't use getattr to fetch inline data after getting Fcr caps,
because it can cause deadlock. The solution is try bringing inline
data to page cache when not holding any cap, and hope the inline
data page is still there after getting the Fcr caps. If the page
is still there, pin it in page cache for later IO.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 4a3f55f..5d2b88e 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1207,6 +1207,7 @@
struct inode *inode = file_inode(vma->vm_file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_file_info *fi = vma->vm_file->private_data;
+ struct page *pinned_page = NULL;
loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
int want, got, ret;
@@ -1218,7 +1219,8 @@
want = CEPH_CAP_FILE_CACHE;
while (1) {
got = 0;
- ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);
+ ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, -1,
+ &got, &pinned_page);
if (ret == 0)
break;
if (ret != -ERESTARTSYS) {
@@ -1233,6 +1235,8 @@
dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
+ if (pinned_page)
+ page_cache_release(pinned_page);
ceph_put_cap_refs(ci, got);
return ret;
@@ -1266,7 +1270,8 @@
want = CEPH_CAP_FILE_BUFFER;
while (1) {
got = 0;
- ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, off + len);
+ ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
+ &got, NULL);
if (ret == 0)
break;
if (ret != -ERESTARTSYS) {