[PVFS2-CVS] commit by neill in pvfs2/src/apps/kernel/linux: pvfs2-client-core.c

[CVS commit program]

Update of /projects/cvsroot/pvfs2/src/apps/kernel/linux
In directory parlweb:/tmp/cvs-serv21797/src/apps/kernel/linux

Modified Files:
	pvfs2-client-core.c 
Log Message:
- make sure that -EEXIST is only ever returned if the file open flags
  included O_EXCL.  if the flag wasn't specified, we have to return
  success on the open (a much dirtier 'perform a blocking sys_lookup
  call after a failed sys_create call' was done in the last client, but
  removed during the non-blocking merge).  this is the last piece of
  that removal that allows us not to break.  the vfs handles this all
  for us, as long as we don't try to skip a lookup before create
  (using the intent information passed into the lookup)
- add comments in the proper places regarding this behaviour
- test program/framework addition (file_open.c) that tests various
  file open flags and error codes (and can easily catch the above
  case)
- test program threaded_write update to use strerror on open error
- some kernel code debugging cosmetic changes


Index: pvfs2-client-core.c
===================================================================
RCS file: /projects/cvsroot/pvfs2/src/apps/kernel/linux/pvfs2-client-core.c,v
diff -p -u -r1.8 -r1.9
--- pvfs2-client-core.c	15 Jul 2004 16:40:20 -0000	1.8
+++ pvfs2-client-core.c	19 Jul 2004 21:13:13 -0000	1.9
@@ -130,8 +130,7 @@ static int hash_key(void *key, int table
 static int hash_key_compare(void *key, struct qlist_head *link);
 static struct qhash_table *s_ops_in_progress_table = NULL;
 
-
-int write_device_response(
+static int write_device_response(
     void *buffer_list,
     int *size_list,
     int list_size,
@@ -369,7 +368,7 @@ static int post_lookup_request(vfs_reque
     {
         gossip_debug(
             GOSSIP_CLIENT_DEBUG,
-            "Failed to lookup %s on fsid %d (ret=%d)!\n",
+            "Posting of lookup failed: %s on fsid %d (ret=%d)!\n",
             vfs_request->in_upcall.req.lookup.d_name,
             vfs_request->in_upcall.req.lookup.parent_refn.fs_id, ret);
     }
@@ -397,7 +396,7 @@ static int post_create_request(vfs_reque
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("File creation failed", ret);
+        PVFS_perror_gossip("Posting file create failed", ret);
     }
     return ret;
 }
@@ -425,7 +424,7 @@ static int post_symlink_request(vfs_requ
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Symlink creation failed", ret);
+        PVFS_perror_gossip("Posting symlink create failed", ret);
     }
     return ret;
 }
@@ -449,7 +448,7 @@ static int post_getattr_request(vfs_requ
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Getattr failed", ret);
+        PVFS_perror_gossip("Posting getattr failed", ret);
     }
     return ret;
 }
@@ -472,7 +471,7 @@ static int post_setattr_request(vfs_requ
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Setattr failed", ret);
+        PVFS_perror_gossip("Posting setattr failed", ret);
     }
     return ret;
 }
@@ -496,7 +495,7 @@ static int post_remove_request(vfs_reque
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Remove failed",ret);
+        PVFS_perror_gossip("Posting remove failed",ret);
     }
     return ret;
 }
@@ -522,7 +521,7 @@ static int post_mkdir_request(vfs_reques
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Mkdir failed", ret);
+        PVFS_perror_gossip("Posting mkdir failed", ret);
     }
     return ret;
 }
@@ -548,7 +547,7 @@ static int post_readdir_request(vfs_requ
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Readdir failed", ret);
+        PVFS_perror_gossip("Posting readdir failed", ret);
     }
     return ret;
 }
@@ -578,7 +577,7 @@ static int post_rename_request(vfs_reque
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Rename failed", ret);
+        PVFS_perror_gossip("Posting rename failed", ret);
     }
     return ret;
 }
@@ -602,7 +601,7 @@ static int post_truncate_request(vfs_req
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("Truncate failed", ret);
+        PVFS_perror_gossip("Posting truncate failed", ret);
     }
     return ret;
 }
@@ -936,7 +935,7 @@ static int post_io_readahead_request(vfs
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("File I/O failed", ret);
+        PVFS_perror_gossip("Posting file I/O failed", ret);
     }
     return 0;
 
@@ -1020,7 +1019,7 @@ static int post_io_request(vfs_request_t
 
     if (ret < 0)
     {
-        PVFS_perror_gossip("File I/O failed", ret);
+        PVFS_perror_gossip("Posting file I/O failed", ret);
     }
     return ret;
 }
@@ -1178,6 +1177,21 @@ static inline void package_downcall_memb
         case PVFS2_VFS_OP_CREATE:
             if (error_code)
             {
+                /*
+                  unless O_EXCL was specified at open time from the
+                  vfs, -PVFS_EEXIST shouldn't be an error, but rather
+                  success.  to solve this case, in theory we could do
+                  a lookup on a failed create, but there are problems.
+                  most are consistency races, but aside from those is
+                  that we don't know if the vfs has opened with the
+                  O_EXCL flag at this level.  after much
+                  investigation, it turns out we don't want to know
+                  either.  the vfs (both in 2.4.x and 2.6.x) properly
+                  handles the translated error code (which ends up
+                  being -EEXIST) in the open path and does the right
+                  thing when O_EXCL is specified (i.e. return -EEXIST,
+                  otherwise success).
+                */
                 vfs_request->out_downcall.resp.create.refn.handle =
                     PVFS_HANDLE_NULL;
                 vfs_request->out_downcall.resp.create.refn.fs_id =