xnu-1228.15.4.tar.gz

[apple/xnu.git] / bsd / hfs / hfs_vnops.c

diff --git a/bsd/hfs/hfs_vnops.c b/bsd/hfs/hfs_vnops.c
index 61875f626671835c2aa78314b1c8d2ac58ae195a..6d8d6ad33d8f9c5f9039c1a02e64eabd19c91136 100644 (file)
--- a/bsd/hfs/hfs_vnops.c
+++ b/bsd/hfs/hfs_vnops.c
@@ -367,6 +367,11 @@ hfs_vnop_close(ap)
        }
        
        hfs_unlock(cp);
+
+       if (ap->a_fflag & FWASWRITTEN) {
+               hfs_sync_ejectable(hfsmp);
+       }
+
        return (0);
 }
 
@@ -2619,6 +2624,16 @@ hfs_vnop_rename(ap)
 skip_rm:
        /*
         * All done with tvp and fvp
+        *
+        * We also jump to this point if there was no destination observed during lookup and namei.
+        * However, because only iocounts are held at the VFS layer, there is nothing preventing a 
+        * competing thread from racing us and creating a file or dir at the destination of this rename 
+        * operation.  If this occurs, it may cause us to get a spurious EEXIST out of the cat_rename 
+        * call below.  To preserve rename's atomicity, we need to signal VFS to re-drive the 
+        * namei/lookup and restart the rename operation.  EEXIST is an allowable errno to be bubbled 
+        * out of the rename syscall, but not for this reason, since it is a synonym errno for ENOTEMPTY.
+        * To signal VFS, we return ERECYCLE (which is also used for lookup restarts). This errno
+        * will be swallowed and it will restart the operation.
         */
 
        lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_EXCLUSIVE_LOCK);
@@ -2626,6 +2641,9 @@ skip_rm:
        hfs_systemfile_unlock(hfsmp, lockflags);
 
        if (error) {
+               if (error == EEXIST) {
+                       error = ERECYCLE;
+               }
                goto out;
        }