ceph: use vfs __set_page_dirty_nobuffers interface instead of doing it inside filesystem
Following we will begin to add memcg dirty page accounting around
__set_page_dirty_{buffers,nobuffers} in vfs layer, so we'd better use vfs interface to
avoid exporting those details to filesystems.
Since vfs set_page_dirty() should be called under page lock, here we don't need elaborate
codes to handle racy anymore, and two WARN_ON() are added to detect such exceptions.
Thanks very much for Sage and Yan Zheng's coaching!
I tested it in a two server's ceph environment that one is client and the other is
mds/osd/mon, and run the following fsx test from xfstests:
./fsx 1MB -N 50000 -p 10000 -l 1048576
./fsx 10MB -N 50000 -p 10000 -l 10485760
./fsx 100MB -N 50000 -p 10000 -l 104857600
The fsx does lots of mmap-read/mmap-write/truncate operations and the tests completed
successfully without triggering any of WARN_ON.
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index cb78ce8..3bed7da 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -70,15 +70,16 @@
struct address_space *mapping = page->mapping;
struct inode *inode;
struct ceph_inode_info *ci;
- int undo = 0;
struct ceph_snap_context *snapc;
+ int ret;
if (unlikely(!mapping))
return !TestSetPageDirty(page);
- if (TestSetPageDirty(page)) {
+ if (PageDirty(page)) {
dout("%p set_page_dirty %p idx %lu -- already dirty\n",
mapping->host, page, page->index);
+ BUG_ON(!PagePrivate(page));
return 0;
}
@@ -107,35 +108,19 @@
snapc, snapc->seq, snapc->num_snaps);
spin_unlock(&ci->i_ceph_lock);
- /* now adjust page */
- spin_lock_irq(&mapping->tree_lock);
- if (page->mapping) { /* Race with truncate? */
- WARN_ON_ONCE(!PageUptodate(page));
- account_page_dirtied(page, page->mapping);
- radix_tree_tag_set(&mapping->page_tree,
- page_index(page), PAGECACHE_TAG_DIRTY);
+ /*
+ * Reference snap context in page->private. Also set
+ * PagePrivate so that we get invalidatepage callback.
+ */
+ BUG_ON(PagePrivate(page));
+ page->private = (unsigned long)snapc;
+ SetPagePrivate(page);
- /*
- * Reference snap context in page->private. Also set
- * PagePrivate so that we get invalidatepage callback.
- */
- page->private = (unsigned long)snapc;
- SetPagePrivate(page);
- } else {
- dout("ANON set_page_dirty %p (raced truncate?)\n", page);
- undo = 1;
- }
+ ret = __set_page_dirty_nobuffers(page);
+ WARN_ON(!PageLocked(page));
+ WARN_ON(!page->mapping);
- spin_unlock_irq(&mapping->tree_lock);
-
- if (undo)
- /* whoops, we failed to dirty the page */
- ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
-
- __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-
- BUG_ON(!PageDirty(page));
- return 1;
+ return ret;
}
/*