nfs: fix the handling of replies to MKNOD and SYMLINK

The Linux NFS server does not accept a setting of file size to 0 for
sockets and FIFOs so there is code to strip that for those cases. I also
spotted that the file modification times were not being applied to a
created file so there is now just one rpc to set all file attributes using
xdr_encode_create_state(). This sets the times to be server time which is
appropriate for a new file (even though it was created in the previous RPC
call). The previous code was supplying the 'gid' based on that returned by
the 'stat' but I don't think that can be relied on since the V3 protocol
states that CREATE3 using EXCLUSIVE cannot guarantee any file attributes
until after the SETATTR3.

2 files changed, 47 insertions, 37 deletions

diff --git a/nfs/nfs.c b/nfs/nfs.c
index 313c1e4a..40e62669 100644
--- a/nfs/nfs.c
+++ b/nfs/nfs.c
@@ -25,6 +25,7 @@
 
 #include <string.h>
 #include <netinet/in.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <sys/sysmacros.h>
 
@@ -179,6 +180,30 @@ xdr_encode_string (int *p, const char *string)
   return xdr_encode_data (p, string, strlen (string));
 }
 
+/* Some NFSv3 rpcs can fail if the file size field
+   is set within the set attributes unnecessarily. */
+static inline bool
+nfs_sattr3_size_needed(mode_t mode, size_t sz)
+{
+  if (sz == 0)
+    {
+      switch (hurd_mode_to_nfs_type (mode))
+	{
+	case NFSOCK:
+	case NF3FIFO:
+	  /* NFCHR and NFBLK probaly also fall into this
+	     category but as unable to check then leave
+	     those alone. */
+	  return false;
+
+	default:
+	  break;
+	}
+    }
+
+  return true;
+}
+
 /* Encode a MODE into an otherwise empty sattr.  */
 int *
 xdr_encode_sattr_mode (int *p, mode_t mode)
@@ -372,14 +397,17 @@ xdr_encode_sattr_stat (int *p,
     }
   else
     {
+      bool needs_size = nfs_sattr3_size_needed (st->st_mode, st->st_size);
+
       *(p++) = htonl (1);		/* set mode */
       *(p++) = htonl (hurd_mode_to_nfs_mode (st->st_mode));
       *(p++) = htonl (1);		/* set uid */
       *(p++) = htonl (st->st_uid);
       *(p++) = htonl (1);		/* set gid */
       *(p++) = htonl (st->st_gid);
-      *(p++) = htonl (1);		/* set size */
-      p = xdr_encode_64bit (p, st->st_size);
+      *(p++) = htonl (needs_size);	/* set size */
+      if (needs_size)
+	p = xdr_encode_64bit (p, st->st_size);
       *(p++) = htonl (SET_TO_CLIENT_TIME); /* set atime */
       *(p++) = htonl (st->st_atim.tv_sec);
       *(p++) = htonl (st->st_atim.tv_nsec);
diff --git a/nfs/ops.c b/nfs/ops.c
index 646e206c..2976641f 100644
--- a/nfs/ops.c
+++ b/nfs/ops.c
@@ -1056,8 +1056,6 @@ netfs_attempt_link (struct iouser *cred, struct node *dir,
 	}
       pthread_mutex_unlock (&np->lock);
 
-      pthread_mutex_lock (&dir->lock);
-
       purge_lookup_cache (dir, name, strlen (name));
       err = conduct_rpc (&rpcbuf, &p);
       if (!err)
@@ -1068,6 +1066,7 @@ netfs_attempt_link (struct iouser *cred, struct node *dir,
 	  if (protocol_version == 2 && !err)
 	    {
 	      free (rpcbuf);
+	      pthread_mutex_lock (&dir->lock);
 
 	      /* NFSPROC_SYMLINK stupidly does not pass back an
 		 fhandle, so we have to fetch one now. */
@@ -1101,23 +1100,14 @@ netfs_attempt_link (struct iouser *cred, struct node *dir,
 	    }
 	  else if (protocol_version == 3)
 	    {
-	      if (!err)
-		{
-		  pthread_mutex_unlock (&dir->lock);
-		  pthread_mutex_lock (&np->lock);
-		  p = recache_handle (p, np);
-		  p = process_returned_stat (np, p, 1);
-		  pthread_mutex_unlock (&np->lock);
-		  pthread_mutex_lock (&dir->lock);
-		}
-	      p = process_wcc_stat (dir, p, !err);
-	      pthread_mutex_unlock (&dir->lock);
+	      /* process_create_reply needs the start of the buffer */
+	      p--;
+
+	      pthread_mutex_lock (&np->lock);
+	      err = process_create_reply (cred, dir, name, &np, p);
+	      pthread_mutex_unlock (&np->lock);
 	    }
-	  else
-	    pthread_mutex_unlock (&dir->lock);
 	}
-      else
-	pthread_mutex_unlock (&dir->lock);
 
       free (rpcbuf);
       break;
@@ -1213,19 +1203,9 @@ netfs_attempt_link (struct iouser *cred, struct node *dir,
 	  err = conduct_rpc (&rpcbuf, &p);
 	  if (!err)
 	    {
-	      err = nfs_error_trans (ntohl (*p));
-	      p++;
-
-	      if (!err)
-		{
-		  pthread_mutex_lock (&np->lock);
-		  p = recache_handle (p, np);
-		  p = process_returned_stat (np, p, 1);
-		  pthread_mutex_unlock (&np->lock);
-		}
-	      pthread_mutex_lock (&dir->lock);
-	      p = process_wcc_stat (dir, p, !err);
-	      pthread_mutex_unlock (&dir->lock);
+	      pthread_mutex_lock (&np->lock);
+	      err = process_create_reply (cred, dir, name, &np, p);
+	      pthread_mutex_unlock (&np->lock);
 	    }
 	  free (rpcbuf);
 	}
@@ -1381,13 +1361,15 @@ netfs_attempt_create_file (struct iouser *cred, struct node *np,
       else
 	err = process_create_reply (cred, np, name, newnp, p);
 
-      if (*newnp && !netfs_validate_stat (*newnp, (struct iouser *) -1))
+      if (protocol_version == 3 && !err)
 	{
-	  if ((*newnp)->nn_stat.st_uid != owner)
-	    err = netfs_attempt_chown ((struct iouser *) -1, *newnp, owner, (*newnp)->nn_stat.st_gid);
+	  int *_cs_sattr_encoder (int * sp)
+	  {
+	    return xdr_encode_create_state (sp, mode, owner);
+	  }
 
-	  if (!err && (*newnp)->nn_stat.st_mode != mode)
-	    err = netfs_attempt_chmod (cred, *newnp, mode);
+	  err = nfs_setattr_rpc(cred, *newnp, -1, _cs_sattr_encoder);
+	  /* Unlink *newnp if err ? */
 	}
     }