ceph: set i_head_snapc when getting CEPH_CAP_FILE_WR reference

[firefly-linux-kernel-4.4.55.git] / fs / ceph / addr.c

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index ccc4325aa5c5793cc8c06e6a22c34643a6c63c0b..5f53ac0d9d7c37eb26dd9606d464f3bb69c2cb5e 100644 (file)
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -87,17 +87,21 @@ static int ceph_set_page_dirty(struct page *page)
        inode = mapping->host;
        ci = ceph_inode(inode);
 
-       /*
-        * Note that we're grabbing a snapc ref here without holding
-        * any locks!
-        */
-       snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
-
        /* dirty the head */
        spin_lock(&ci->i_ceph_lock);
-       if (ci->i_head_snapc == NULL)
-               ci->i_head_snapc = ceph_get_snap_context(snapc);
-       ++ci->i_wrbuffer_ref_head;
+       BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
+       if (__ceph_have_pending_cap_snap(ci)) {
+               struct ceph_cap_snap *capsnap =
+                               list_last_entry(&ci->i_cap_snaps,
+                                               struct ceph_cap_snap,
+                                               ci_item);
+               snapc = ceph_get_snap_context(capsnap->context);
+               capsnap->dirty_pages++;
+       } else {
+               BUG_ON(!ci->i_head_snapc);
+               snapc = ceph_get_snap_context(ci->i_head_snapc);
+               ++ci->i_wrbuffer_ref_head;
+       }
        if (ci->i_wrbuffer_ref == 0)
                ihold(inode);
        ++ci->i_wrbuffer_ref;
@@ -1033,7 +1037,6 @@ static int ceph_update_writeable_page(struct file *file,
 {
        struct inode *inode = file_inode(file);
        struct ceph_inode_info *ci = ceph_inode(inode);
-       struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
        loff_t page_off = pos & PAGE_CACHE_MASK;
        int pos_in_page = pos & ~PAGE_CACHE_MASK;
        int end_in_page = pos_in_page + len;
@@ -1045,10 +1048,6 @@ retry_locked:
        /* writepages currently holds page lock, but if we change that later, */
        wait_on_page_writeback(page);
 
-       /* check snap context */
-       BUG_ON(!ci->i_snap_realm);
-       down_read(&mdsc->snap_rwsem);
-       BUG_ON(!ci->i_snap_realm->cached_context);
        snapc = page_snap_context(page);
        if (snapc && snapc != ci->i_head_snapc) {
                /*
@@ -1056,7 +1055,6 @@ retry_locked:
                 * context!  is it writeable now?
                 */
                oldest = get_oldest_context(inode, NULL);
-               up_read(&mdsc->snap_rwsem);
 
                if (snapc->seq > oldest->seq) {
                        ceph_put_snap_context(oldest);
@@ -1113,7 +1111,6 @@ retry_locked:
        }
 
        /* we need to read it. */
-       up_read(&mdsc->snap_rwsem);
        r = readpage_nounlock(file, page);
        if (r < 0)
                goto fail_nosnap;
@@ -1158,16 +1155,13 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 
 /*
  * we don't do anything in here that simple_write_end doesn't do
- * except adjust dirty page accounting and drop read lock on
- * mdsc->snap_rwsem.
+ * except adjust dirty page accounting
  */
 static int ceph_write_end(struct file *file, struct address_space *mapping,
                          loff_t pos, unsigned len, unsigned copied,
                          struct page *page, void *fsdata)
 {
        struct inode *inode = file_inode(file);
-       struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-       struct ceph_mds_client *mdsc = fsc->mdsc;
        unsigned from = pos & (PAGE_CACHE_SIZE - 1);
        int check_cap = 0;
 
@@ -1189,7 +1183,6 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
        set_page_dirty(page);
 
        unlock_page(page);
-       up_read(&mdsc->snap_rwsem);
        page_cache_release(page);
 
        if (check_cap)
@@ -1315,7 +1308,6 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
        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 ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
        struct page *page = vmf->page;
        loff_t off = page_offset(page);
        loff_t size = i_size_read(inode);
@@ -1374,7 +1366,6 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
        if (ret == 0) {
                /* success.  we'll keep the page locked. */
                set_page_dirty(page);
-               up_read(&mdsc->snap_rwsem);
                ret = VM_FAULT_LOCKED;
        } else {
                if (ret == -ENOMEM)