@@ -1299,40 +1299,34 @@ static int context_is_writeable_or_written(struct inode *inode,
return ret;
}
-/*
- * We are only allowed to write into/dirty the page if the page is
- * clean, or already dirty within the same snap context.
+/**
+ * ceph_find_incompatible - find an incompatible context and return it
+ * @inode: inode associated with page
+ * @page: page being dirtied
*
- * called with page locked.
- * return success with page locked,
- * or any failure (incl -EAGAIN) with page unlocked.
+ * Returns NULL on success, negative error code on error, and a snapc ref that should be
+ * waited on otherwise.
*/
-static int ceph_update_writeable_page(struct file *file,
- loff_t pos, unsigned len,
- struct page *page)
+static struct ceph_snap_context *
+ceph_find_incompatible(struct inode *inode, struct page *page)
{
- struct inode *inode = file_inode(file);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
- loff_t page_off = pos & PAGE_MASK;
- int pos_in_page = pos & ~PAGE_MASK;
- int end_in_page = pos_in_page + len;
- loff_t i_size;
- int r;
- struct ceph_snap_context *snapc, *oldest;
if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
dout(" page %p forced umount\n", page);
- unlock_page(page);
- return -EIO;
+ return ERR_PTR(-EIO);
}
-retry_locked:
- /* writepages currently holds page lock, but if we change that later, */
- wait_on_page_writeback(page);
+ for (;;) {
+ struct ceph_snap_context *snapc, *oldest;
+
+ wait_on_page_writeback(page);
+
+ snapc = page_snap_context(page);
+ if (!snapc || snapc == ci->i_head_snapc)
+ break;
- snapc = page_snap_context(page);
- if (snapc && snapc != ci->i_head_snapc) {
/*
* this page is already dirty in another (older) snap
* context! is it writeable now?
@@ -1347,26 +1341,56 @@ static int ceph_update_writeable_page(struct file *file,
* be writeable or written
*/
snapc = ceph_get_snap_context(snapc);
- unlock_page(page);
- ceph_queue_writeback(inode);
- r = wait_event_killable(ci->i_cap_wq,
- context_is_writeable_or_written(inode, snapc));
- ceph_put_snap_context(snapc);
- if (r == -ERESTARTSYS)
- return r;
- return -EAGAIN;
+ return snapc;
}
ceph_put_snap_context(oldest);
/* yay, writeable, do it now (without dropping page lock) */
dout(" page %p snapc %p not current, but oldest\n",
page, snapc);
- if (!clear_page_dirty_for_io(page))
- goto retry_locked;
- r = writepage_nounlock(page, NULL);
- if (r < 0)
+ if (clear_page_dirty_for_io(page)) {
+ int r = writepage_nounlock(page, NULL);
+ if (r < 0)
+ return ERR_PTR(r);
+ }
+ }
+ return NULL;
+}
+
+/*
+ * We are only allowed to write into/dirty the page if the page is
+ * clean, or already dirty within the same snap context.
+ *
+ * called with page locked.
+ * return success with page locked,
+ * or any failure (incl -EAGAIN) with page unlocked.
+ */
+static int ceph_update_writeable_page(struct file *file,
+ loff_t pos, unsigned len,
+ struct page *page)
+{
+ struct inode *inode = file_inode(file);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_snap_context *snapc;
+ loff_t page_off = pos & PAGE_MASK;
+ int pos_in_page = pos & ~PAGE_MASK;
+ int end_in_page = pos_in_page + len;
+ loff_t i_size;
+ int r;
+
+retry_locked:
+ snapc = ceph_find_incompatible(inode, page);
+ if (snapc) {
+ if (IS_ERR(snapc)) {
+ r = PTR_ERR(snapc);
goto fail_unlock;
- goto retry_locked;
+ }
+ unlock_page(page);
+ ceph_queue_writeback(inode);
+ r = wait_event_killable(ci->i_cap_wq,
+ context_is_writeable_or_written(inode, snapc));
+ ceph_put_snap_context(snapc);
+ return -EAGAIN;
}
if (PageUptodate(page)) {
When dirtying a page, we have to flush incompatible contexts. Move that into a separate function. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/ceph/addr.c | 96 +++++++++++++++++++++++++++++++------------------- 1 file changed, 60 insertions(+), 36 deletions(-)