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>

diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index c9b8d0c..43e3aeb 100644 (file)
--- 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;
        }