performance/io-cache: don't use stat got in read_cbk if it is zero-filled.

- translators like io-cache, read-ahead return a zero-filled stbuf in
    readv_cbk and usage of zero filled stat for cache validation is not
    correct.

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 376 (server-side io-cache is preventing client-side io-cache from working)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=376

2 files changed, 28 insertions, 16 deletions

diff --git a/xlators/performance/io-cache/src/io-cache.c b/xlators/performance/io-cache/src/io-cache.c
index fc38ac81af9..ba170c3380e 100644
--- a/xlators/performance/io-cache/src/io-cache.c
+++ b/xlators/performance/io-cache/src/io-cache.c
@@ -192,19 +192,21 @@ ioc_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 	inode_ctx_get (inode, this, &tmp_ioc_inode);
 	ioc_inode = (ioc_inode_t *)(long)tmp_ioc_inode;
 	if (ioc_inode) {
+		ioc_inode_lock (ioc_inode);
+		{
+                        if (ioc_inode->mtime == 0) {
+                                ioc_inode->mtime = stbuf->st_mtime;
+                        }
+		}
+		ioc_inode_unlock (ioc_inode);
+
 		cache_still_valid = ioc_cache_still_valid (ioc_inode, 
 							   stbuf);
 		
 		if (!cache_still_valid) {
 			ioc_inode_flush (ioc_inode);
 		} 
-		/* update the time-stamp of revalidation */
-		ioc_inode_lock (ioc_inode);
-		{
-			gettimeofday (&ioc_inode->tv, NULL);
-		}
-		ioc_inode_unlock (ioc_inode);
-		
+
 		ioc_table_lock (ioc_inode->table);
 		{
 			list_move_tail (&ioc_inode->inode_lru,
@@ -534,6 +536,11 @@ ioc_create_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 			weight = ioc_get_priority (table, path);
 
 			ioc_inode = ioc_inode_update (table, inode, weight);
+                        ioc_inode_lock (ioc_inode);
+                        {
+                                ioc_inode->mtime = buf->st_mtime;
+                        }
+                        ioc_inode_unlock (ioc_inode);
 
                         inode_ctx_put (fd->inode, this,
                                        (uint64_t)(long)ioc_inode);
diff --git a/xlators/performance/io-cache/src/page.c b/xlators/performance/io-cache/src/page.c
index 9db42bca1aa..b3833fff02c 100644
--- a/xlators/performance/io-cache/src/page.c
+++ b/xlators/performance/io-cache/src/page.c
@@ -334,6 +334,7 @@ ioc_fault_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 	size_t      page_size = 0;
 	ioc_waitq_t *waitq = NULL;
         size_t      iobref_page_size = 0;
+        char        zero_filled = 0;
 
         local = frame->local;
         offset = local->pending_offset;
@@ -343,22 +344,26 @@ ioc_fault_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 	trav_offset = offset;  
 	payload_size = op_ret;
 
+        zero_filled = ((op_ret >=0)
+                       && (stbuf->st_mtime == 0));
+
+
 	ioc_inode_lock (ioc_inode);
 	{
-		if (op_ret == -1 || 
-		    (op_ret >= 0 && 
-		     !ioc_cache_still_valid(ioc_inode, stbuf))) {
+		if (op_ret == -1 ||
+		    !(zero_filled ||
+                      ioc_cache_still_valid(ioc_inode, stbuf))) {
 			gf_log (ioc_inode->table->xl->name, GF_LOG_TRACE,
 				"cache for inode(%p) is invalid. flushing "
 				"all pages", ioc_inode);
 			destroy_size = __ioc_inode_flush (ioc_inode);
-		} 
-    
-		if (op_ret >= 0)
-			ioc_inode->mtime = stbuf->st_mtime;
-    
+		}
+
+		if ((op_ret >= 0) && !zero_filled)
+                        ioc_inode->mtime = stbuf->st_mtime;
+
 		gettimeofday (&ioc_inode->tv, NULL);
-    
+
 		if (op_ret < 0) {
 			/* error, readv returned -1 */
 			page = ioc_page_get (ioc_inode, offset);