orangefs: get rid of readdir_handle_s

no point, really - we couldn't keep those across the calls of
getdents(); it would be too easy to DoS, having all slots exhausted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index 259b667..53a4117 100644 (file)
--- a/fs/orangefs/dir.c
+++ b/fs/orangefs/dir.c
@@ -8,11 +8,6 @@
 #include "orangefs-kernel.h"
 #include "orangefs-bufmap.h"
 
-struct readdir_handle_s {
-       struct orangefs_readdir_response_s readdir_response;
-       void *dents_buf;
-};
-
 /*
  * decode routine used by kmod to deal with the blob sent from
  * userspace for readdirs. The blob contains zero or more of these
@@ -141,44 +136,6 @@ out:
        return ret;
 }
 
-static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
-                               size_t size)
-{
-       long ret;
-
-       if (buf == NULL) {
-               gossip_err
-                   ("Invalid NULL buffer specified in readdir_handle_ctor\n");
-               return -ENOMEM;
-       }
-       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);
-               gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", buf);
-               vfree(buf);
-               rhandle->dents_buf = NULL;
-       }
-       return ret;
-}
-
-static void readdir_handle_dtor(struct readdir_handle_s *rhandle)
-{
-       if (rhandle == NULL)
-               return;
-
-       /* kfree(NULL) is safe */
-       kfree(rhandle->readdir_response.dirent_array);
-       rhandle->readdir_response.dirent_array = NULL;
-
-       if (rhandle->dents_buf) {
-               gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n",
-                            rhandle->dents_buf);
-               vfree(rhandle->dents_buf);
-               rhandle->dents_buf = NULL;
-       }
-}
-
 /*
  * Read directory entries from an instance of an open directory.
  */
@@ -198,7 +155,8 @@ static int orangefs_readdir(struct file *file, struct dir_context *ctx)
        struct orangefs_kernel_op_s *new_op = NULL;
        struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(dentry->d_inode);
        int buffer_full = 0;
-       struct readdir_handle_s rhandle;
+       struct orangefs_readdir_response_s readdir_response;
+       void *dents_buf;
        int i = 0;
        int len = 0;
        ino_t current_ino = 0;
@@ -224,8 +182,7 @@ 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.dents_buf = NULL;
-       memset(&rhandle.readdir_response, 0, sizeof(rhandle.readdir_response));
+       memset(&readdir_response, 0, sizeof(readdir_response));
 
        new_op = op_alloc(ORANGEFS_VFS_OP_READDIR);
        if (!new_op)
@@ -278,7 +235,7 @@ get_new_buffer_index:
        if (ret == -EIO && op_state_purged(new_op)) {
                gossip_err("%s: Client is down. Aborting readdir call.\n",
                        __func__);
-               goto out_free_op;
+               goto out_slot;
        }
 
        if (ret < 0 || new_op->downcall.status != 0) {
@@ -287,18 +244,22 @@ get_new_buffer_index:
                             new_op->downcall.status);
                if (ret >= 0)
                        ret = new_op->downcall.status;
-               goto out_free_op;
+               goto out_slot;
+       }
+
+       dents_buf = new_op->downcall.trailer_buf;
+       if (dents_buf == NULL) {
+               gossip_err("Invalid NULL buffer in readdir response\n");
+               ret = -ENOMEM;
+               goto out_slot;
        }
 
-       bytes_decoded =
-               readdir_handle_ctor(&rhandle,
-                                   new_op->downcall.trailer_buf,
-                                   new_op->downcall.trailer_size);
+       bytes_decoded = decode_dirents(dents_buf, new_op->downcall.trailer_size,
+                                       &readdir_response);
        if (bytes_decoded < 0) {
-               gossip_err("orangefs_readdir: Could not decode trailer buffer into a readdir response %d\n",
-                       ret);
                ret = bytes_decoded;
-               goto out_free_op;
+               gossip_err("Could not decode readdir from buffer %d\n", ret);
+               goto out_vfree;
        }
 
        if (bytes_decoded != new_op->downcall.trailer_size) {
@@ -345,14 +306,14 @@ get_new_buffer_index:
        gossip_debug(GOSSIP_DIR_DEBUG,
                     "%s: dirent_outcount:%d:\n",
                     __func__,
-                    rhandle.readdir_response.orangefs_dirent_outcount);
+                    readdir_response.orangefs_dirent_outcount);
        for (i = ctx->pos;
-            i < rhandle.readdir_response.orangefs_dirent_outcount;
+            i < readdir_response.orangefs_dirent_outcount;
             i++) {
-               len = rhandle.readdir_response.dirent_array[i].d_length;
-               current_entry = rhandle.readdir_response.dirent_array[i].d_name;
+               len = readdir_response.dirent_array[i].d_length;
+               current_entry = readdir_response.dirent_array[i].d_name;
                current_ino = orangefs_khandle_to_ino(
-                       &(rhandle.readdir_response.dirent_array[i].khandle));
+                       &readdir_response.dirent_array[i].khandle);
 
                gossip_debug(GOSSIP_DIR_DEBUG,
                             "calling dir_emit for %s with len %d"
@@ -382,14 +343,14 @@ get_new_buffer_index:
         * getting another batch...
         */
        if (ret) {
-               *ptoken = rhandle.readdir_response.token;
+               *ptoken = readdir_response.token;
                ctx->pos = ORANGEFS_ITERATE_NEXT;
        }
 
        /*
         * Did we hit the end of the directory?
         */
-       if (rhandle.readdir_response.token == ORANGEFS_READDIR_END &&
+       if (readdir_response.token == ORANGEFS_READDIR_END &&
            !buffer_full) {
                gossip_debug(GOSSIP_DIR_DEBUG,
                "End of dir detected; setting ctx->pos to ORANGEFS_READDIR_END.\n");
@@ -397,7 +358,13 @@ get_new_buffer_index:
        }
 
 out_destroy_handle:
-       readdir_handle_dtor(&rhandle);
+       /* kfree(NULL) is safe */
+       kfree(readdir_response.dirent_array);
+out_vfree:
+       gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", dents_buf);
+       vfree(dents_buf);
+out_slot:
+       orangefs_readdir_index_put(buffer_index);
 out_free_op:
        op_release(new_op);
        gossip_debug(GOSSIP_DIR_DEBUG, "orangefs_readdir returning %d\n", ret);