1 files changed, 50 insertions, 32 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 4958a2ef3e04..e1e6df0f549e 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1362,6 +1362,41 @@ static int __mark_caps_flushing(struct inode *inode,
 }
 
 /*
+ * try to invalidate mapping pages without blocking.
+ */
+static int mapping_is_empty(struct address_space *mapping)
+{
+        struct page *page = find_get_page(mapping, 0);
+
+        if (!page)
+                return 1;
+
+        put_page(page);
+        return 0;
+}
+
+static int try_nonblocking_invalidate(struct inode *inode)
+{
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        u32 invalidating_gen = ci->i_rdcache_gen;
+
+        spin_unlock(&inode->i_lock);
+        invalidate_mapping_pages(&inode->i_data, 0, -1);
+        spin_lock(&inode->i_lock);
+
+        if (mapping_is_empty(&inode->i_data) &&
+            invalidating_gen == ci->i_rdcache_gen) {
+                /* success. */
+                dout("try_nonblocking_invalidate %p success\n", inode);
+                ci->i_rdcache_gen = 0;
+                ci->i_rdcache_revoking = 0;
+                return 0;
+        }
+        dout("try_nonblocking_invalidate %p failed\n", inode);
+        return -1;
+}
+
+/*
  * Swiss army knife function to examine currently used and wanted
  * versus held caps.  Release, flush, ack revoked caps to mds as
  * appropriate.
@@ -1451,27 +1486,19 @@ retry_locked:
             (file_wanted == 0 ||                     /* no open files */
              (revoking & CEPH_CAP_FILE_CACHE)) &&     /*  or revoking cache */
             !tried_invalidate) {
-                u32 invalidating_gen = ci->i_rdcache_gen;
-                int ret;
-
                 dout("check_caps trying to invalidate on %p\n", inode);
-                spin_unlock(&inode->i_lock);
-                ret = invalidate_mapping_pages(&inode->i_data, 0, -1);
-                spin_lock(&inode->i_lock);
-                if (ret == 0 && invalidating_gen == ci->i_rdcache_gen) {
-                        /* success. */
-                        ci->i_rdcache_gen = 0;
-                        ci->i_rdcache_revoking = 0;
-                } else if (revoking & CEPH_CAP_FILE_CACHE) {
-                        dout("check_caps queuing invalidate\n");
-                        queue_invalidate = 1;
-                        ci->i_rdcache_revoking = ci->i_rdcache_gen;
-                } else {
-                        dout("check_caps failed to invalidate pages\n");
-                        /* we failed to invalidate pages.  check these
-                           caps again later. */
-                        force_requeue = 1;
-                        __cap_set_timeouts(mdsc, ci);
+                if (try_nonblocking_invalidate(inode) < 0) {
+                        if (revoking & CEPH_CAP_FILE_CACHE) {
+                                dout("check_caps queuing invalidate\n");
+                                queue_invalidate = 1;
+                                ci->i_rdcache_revoking = ci->i_rdcache_gen;
+                        } else {
+                                dout("check_caps failed to invalidate pages\n");
+                                /* we failed to invalidate pages.  check these
+                                   caps again later. */
+                                force_requeue = 1;
+                                __cap_set_timeouts(mdsc, ci);
+                        }
                 }
                 tried_invalidate = 1;
                 goto retry_locked;
@@ -2184,7 +2211,6 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
         int revoked_rdcache = 0;
         int queue_invalidate = 0;
         int tried_invalidate = 0;
-        int ret;
 
         dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
              inode, cap, mds, seq, ceph_cap_string(newcaps));
@@ -2199,24 +2225,16 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 restart:
         if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
             !ci->i_wrbuffer_ref && !tried_invalidate) {
-                dout("CACHE invalidation\n");
-                spin_unlock(&inode->i_lock);
                 tried_invalidate = 1;
-
-                ret = invalidate_mapping_pages(&inode->i_data, 0, -1);
-                spin_lock(&inode->i_lock);
-                if (ret < 0) {
+                if (try_nonblocking_invalidate(inode) == 0) {
+                        revoked_rdcache = 1;
+                } else {
                         /* there were locked pages.. invalidate later
                            in a separate thread. */
                         if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
                                 queue_invalidate = 1;
                                 ci->i_rdcache_revoking = ci->i_rdcache_gen;
                         }
-                } else {
-                        /* we successfully invalidated those pages */
-                        revoked_rdcache = 1;
-                        ci->i_rdcache_gen = 0;
-                        ci->i_rdcache_revoking = 0;
                 }
                 goto restart;
         }