Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

Pull Ceph fixes from Sage Weil:
 "There are a couple of fixes from Yan for bad pointer dereferences in
  the messenger code and when fiddling with page->private after page
  migration, a fix from Alex for a use-after-free in the osd client
  code, and a couple fixes for the message refcounting and shutdown
  ordering."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: flush msgr queue during mon_client shutdown
  rbd: Clear ceph_msg->bio_iter for retransmitted message
  libceph: use con get/put ops from osd_client
  libceph: osd_client: don't drop reply reference too early
  ceph: check PG_Private flag before accessing page->private

1 files changed, 12 insertions, 9 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 173b1d22e59..8b67304e4b8 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -54,7 +54,12 @@
         (CONGESTION_ON_THRESH(congestion_kb) -                          \
          (CONGESTION_ON_THRESH(congestion_kb) >> 2))
 
-
+static inline struct ceph_snap_context *page_snap_context(struct page *page)
+{
+        if (PagePrivate(page))
+                return (void *)page->private;
+        return NULL;
+}
 
 /*
  * Dirty a page.  Optimistically adjust accounting, on the assumption
@@ -142,10 +147,9 @@ static void ceph_invalidatepage(struct page *page, unsigned long offset)
 {
         struct inode *inode;
         struct ceph_inode_info *ci;
-        struct ceph_snap_context *snapc = (void *)page->private;
+        struct ceph_snap_context *snapc = page_snap_context(page);
 
         BUG_ON(!PageLocked(page));
-        BUG_ON(!page->private);
         BUG_ON(!PagePrivate(page));
         BUG_ON(!page->mapping);
 
@@ -182,7 +186,6 @@ static int ceph_releasepage(struct page *page, gfp_t g)
         struct inode *inode = page->mapping ? page->mapping->host : NULL;
         dout("%p releasepage %p idx %lu\n", inode, page, page->index);
         WARN_ON(PageDirty(page));
-        WARN_ON(page->private);
         WARN_ON(PagePrivate(page));
         return 0;
 }
@@ -443,7 +446,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
         osdc = &fsc->client->osdc;
 
         /* verify this is a writeable snap context */
-        snapc = (void *)page->private;
+        snapc = page_snap_context(page);
         if (snapc == NULL) {
                 dout("writepage %p page %p not dirty?\n", inode, page);
                 goto out;
@@ -451,7 +454,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
         oldest = get_oldest_context(inode, &snap_size);
         if (snapc->seq > oldest->seq) {
                 dout("writepage %p page %p snapc %p not writeable - noop\n",
-                     inode, page, (void *)page->private);
+                     inode, page, snapc);
                 /* we should only noop if called by kswapd */
                 WARN_ON((current->flags & PF_MEMALLOC) == 0);
                 ceph_put_snap_context(oldest);
@@ -591,7 +594,7 @@ static void writepages_finish(struct ceph_osd_request *req,
                         clear_bdi_congested(&fsc->backing_dev_info,
                                             BLK_RW_ASYNC);
 
-                ceph_put_snap_context((void *)page->private);
+                ceph_put_snap_context(page_snap_context(page));
                 page->private = 0;
                 ClearPagePrivate(page);
                 dout("unlocking %d %p\n", i, page);
@@ -795,7 +798,7 @@ get_more_pages:
                         }
 
                         /* only if matching snap context */
-                        pgsnapc = (void *)page->private;
+                        pgsnapc = page_snap_context(page);
                         if (pgsnapc->seq > snapc->seq) {
                                 dout("page snapc %p %lld > oldest %p %lld\n",
                                      pgsnapc, pgsnapc->seq, snapc, snapc->seq);
@@ -984,7 +987,7 @@ retry_locked:
         BUG_ON(!ci->i_snap_realm);
         down_read(&mdsc->snap_rwsem);
         BUG_ON(!ci->i_snap_realm->cached_context);
-        snapc = (void *)page->private;
+        snapc = page_snap_context(page);
         if (snapc && snapc != ci->i_head_snapc) {
                 /*
                  * this page is already dirty in another (older) snap