orangefs: free readdir buffer index before the dir_emit loop

We only need it while the service operation is actually in progress
since it is only used to co-ordinate the client-core's memory use. The
kernel allocates its own space.

Also clean up some comments which mislead the reader into thinking
the readdir buffers are shared memory.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

1 files changed, 9 insertions, 25 deletions

diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index c9b8d0ced833..43e3aeb529ea 100644
--- a/fs/orangefs/dir.c
+++ b/fs/orangefs/dir.c
@@ -9,7 +9,6 @@
 #include "orangefs-bufmap.h"
 
 struct readdir_handle_s {
-        int buffer_index;
         struct orangefs_readdir_response_s readdir_response;
         void *dents_buf;
 };
@@ -143,7 +142,7 @@ out:
 }
 
 static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
-                                size_t size, int buffer_index)
+                                size_t size)
 {
         long ret;
 
@@ -152,17 +151,10 @@ static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
                     ("Invalid NULL buffer specified in readdir_handle_ctor\n");
                 return -ENOMEM;
         }
-        if (buffer_index < 0) {
-                gossip_err
-                    ("Invalid buffer index specified in readdir_handle_ctor\n");
-                return -EINVAL;
-        }
-        rhandle->buffer_index = buffer_index;
         rhandle->dents_buf = buf;
         ret = decode_dirents(buf, size, &rhandle->readdir_response);
         if (ret < 0) {
                 gossip_err("Could not decode readdir from buffer %ld\n", ret);
-                rhandle->buffer_index = -1;
                 gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", buf);
                 vfree(buf);
                 rhandle->dents_buf = NULL;
@@ -179,10 +171,6 @@ static void readdir_handle_dtor(struct readdir_handle_s *rhandle)
         kfree(rhandle->readdir_response.dirent_array);
         rhandle->readdir_response.dirent_array = NULL;
 
-        if (rhandle->buffer_index >= 0) {
-                orangefs_readdir_index_put(rhandle->buffer_index);
-                rhandle->buffer_index = -1;
-        }
         if (rhandle->dents_buf) {
                 gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n",
                              rhandle->dents_buf);
@@ -236,7 +224,6 @@ static int orangefs_readdir(struct file *file, struct dir_context *ctx)
                      "orangefs_readdir called on %s (pos=%llu)\n",
                      dentry->d_name.name, llu(pos));
 
-        rhandle.buffer_index = -1;
         rhandle.dents_buf = NULL;
         memset(&rhandle.readdir_response, 0, sizeof(rhandle.readdir_response));
 
@@ -244,6 +231,10 @@ static int orangefs_readdir(struct file *file, struct dir_context *ctx)
         if (!new_op)
                 return -ENOMEM;
 
+        /*
+         * Only the indices are shared. No memory is actually shared, but the
+         * mechanism is used.
+         */
         new_op->uses_shared_memory = 1;
         new_op->upcall.req.readdir.refn = orangefs_inode->refn;
         new_op->upcall.req.readdir.max_dirent_count =
@@ -274,23 +265,19 @@ get_new_buffer_index:
                      new_op->downcall.status,
                      ret);
 
+        orangefs_readdir_index_put(buffer_index);
+
         if (ret == -EAGAIN && op_state_purged(new_op)) {
-                /*
-                 * readdir shared memory aread has been wiped due to
-                 * pvfs2-client-core restarting, so we must get a new
-                 * index into the shared memory.
-                 */
+                /* Client-core indices are invalid after it restarted. */
                 gossip_debug(GOSSIP_DIR_DEBUG,
                         "%s: Getting new buffer_index for retry of readdir..\n",
                          __func__);
-                orangefs_readdir_index_put(buffer_index);
                 goto get_new_buffer_index;
         }
 
         if (ret == -EIO && op_state_purged(new_op)) {
                 gossip_err("%s: Client is down. Aborting readdir call.\n",
                         __func__);
-                orangefs_readdir_index_put(buffer_index);
                 goto out_free_op;
         }
 
@@ -298,7 +285,6 @@ get_new_buffer_index:
                 gossip_debug(GOSSIP_DIR_DEBUG,
                              "Readdir request failed.  Status:%d\n",
                              new_op->downcall.status);
-                orangefs_readdir_index_put(buffer_index);
                 if (ret >= 0)
                         ret = new_op->downcall.status;
                 goto out_free_op;
@@ -307,13 +293,11 @@ get_new_buffer_index:
         bytes_decoded =
                 readdir_handle_ctor(&rhandle,
                                     new_op->downcall.trailer_buf,
-                                    new_op->downcall.trailer_size,
-                                    buffer_index);
+                                    new_op->downcall.trailer_size);
         if (bytes_decoded < 0) {
                 gossip_err("orangefs_readdir: Could not decode trailer buffer into a readdir response %d\n",
                         ret);
                 ret = bytes_decoded;
-                orangefs_readdir_index_put(buffer_index);
                 goto out_free_op;
         }