fs/9p: When doing inode lookup compare qid details and inode mode bits.

This make sure we don't use wrong inode from the inode hash. The inode number
of the file deleted is reused by the next file system object created
and if we only use inode number for inode hash lookup we could end up
with wrong struct inode.

Also compare inode generation number. Not all Linux file system provide
st_gen in userspace. So it could be 0;

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/cache.c b/fs/9p/cache.c
index 5b335c5..945aa5f 100644
--- a/fs/9p/cache.c
+++ b/fs/9p/cache.c
@@ -108,11 +108,10 @@
 					 void *buffer, uint16_t bufmax)
 {
 	const struct v9fs_inode *v9inode = cookie_netfs_data;
-	memcpy(buffer, &v9inode->fscache_key->path,
-	       sizeof(v9inode->fscache_key->path));
+	memcpy(buffer, &v9inode->qid.path, sizeof(v9inode->qid.path));
 	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &v9inode->vfs_inode,
-		   v9inode->fscache_key->path);
-	return sizeof(v9inode->fscache_key->path);
+		   v9inode->qid.path);
+	return sizeof(v9inode->qid.path);
 }
 
 static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
@@ -129,11 +128,10 @@
 					 void *buffer, uint16_t buflen)
 {
 	const struct v9fs_inode *v9inode = cookie_netfs_data;
-	memcpy(buffer, &v9inode->fscache_key->version,
-	       sizeof(v9inode->fscache_key->version));
+	memcpy(buffer, &v9inode->qid.version, sizeof(v9inode->qid.version));
 	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &v9inode->vfs_inode,
-		   v9inode->fscache_key->version);
-	return sizeof(v9inode->fscache_key->version);
+		   v9inode->qid.version);
+	return sizeof(v9inode->qid.version);
 }
 
 static enum
@@ -143,11 +141,11 @@
 {
 	const struct v9fs_inode *v9inode = cookie_netfs_data;
 
-	if (buflen != sizeof(v9inode->fscache_key->version))
+	if (buflen != sizeof(v9inode->qid.version))
 		return FSCACHE_CHECKAUX_OBSOLETE;
 
-	if (memcmp(buffer, &v9inode->fscache_key->version,
-		   sizeof(v9inode->fscache_key->version)))
+	if (memcmp(buffer, &v9inode->qid.version,
+		   sizeof(v9inode->qid.version)))
 		return FSCACHE_CHECKAUX_OBSOLETE;
 
 	return FSCACHE_CHECKAUX_OKAY;