[PATCH v7 5/5] server: Handle destination file replaced by a directory after trying the rename.

[Gabriel Ivăncescu]

From: Gabriel Ivăncescu

This avoids the fstat call check, reducing syscalls in the most common case.

Signed-off-by: Gabriel Ivăncescu 
---
 server/fd.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/server/fd.c b/server/fd.c
index 5ccca271b8a..3ccd1acff30 100644
--- a/server/fd.c
+++ b/server/fd.c
@@ -2733,14 +2733,10 @@ static void set_fd_name( struct fd *fd, struct fd *root, const char *nameptr, da
         }

/* link() expects that the target doesn't exist */
-        /* rename() cannot replace files with directories */
-        if (create_link || (!fstat( fd->unix_fd, &st ) && S_ISDIR( st.st_mode )))
+        if (create_link && unlink( name ))
         {
-            if (unlink( name ))
-            {
-                file_set_error();
-                goto failed;
-            }
+            file_set_error();
+            goto failed;
         }
     }

@@ -2754,8 +2750,18 @@ static void set_fd_name( struct fd *fd, struct fd *root, const char *nameptr, da

if (rename( fd->unix_name, name ))
     {
-        file_set_error();
-        goto failed;
+        if (errno != ENOTDIR)
+        {
+            file_set_error();
+            goto failed;
+        }
+
+        /* rename() cannot replace files with directories */
+        if (unlink( name ) || rename( fd->unix_name, name ))
+        {
+            file_set_error();
+            goto failed;
+        }
     }

if (is_file_executable( fd->unix_name ) != is_file_executable( name ) && !fstat( fd->unix_fd, &st ))