[XFS] Start writeout earlier (on last close) in the case where we have a

truncate down followed by delayed allocation (buffered writes) - worst
case scenario for the notorious NULL files problem.  This reduces the
window where we are exposed to that problem significantly.

SGI-PV: 917976
SGI-Modid: xfs-linux-melb:xfs-kern:26100a

Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 7c9f7598807f..97615cc74ef5 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -324,6 +324,17 @@ xfs_file_open(
 }
 
 STATIC int
+xfs_file_close(
+        struct file     *filp)
+{
+        vnode_t         *vp = vn_from_inode(filp->f_dentry->d_inode);
+        int             error;
+
+        VOP_CLOSE(vp, 0, file_count(filp) > 1 ? L_FALSE : L_TRUE, NULL, error);
+        return -error;
+}
+
+STATIC int
 xfs_file_release(
         struct inode    *inode,
         struct file     *filp)
@@ -349,6 +360,8 @@ xfs_file_fsync(
 
         if (datasync)
                 flags |= FSYNC_DATA;
+        if (VN_TRUNC(vp))
+                VUNTRUNCATE(vp);
         VOP_FSYNC(vp, flags, NULL, (xfs_off_t)0, (xfs_off_t)-1, error);
         return -error;
 }
@@ -578,6 +591,7 @@ const struct file_operations xfs_file_operations = {
 #endif
         .mmap           = xfs_file_mmap,
         .open           = xfs_file_open,
+        .flush          = xfs_file_close,
         .release        = xfs_file_release,
         .fsync          = xfs_file_fsync,
 #ifdef HAVE_FOP_OPEN_EXEC
@@ -602,6 +616,7 @@ const struct file_operations xfs_invis_file_operations = {
 #endif
         .mmap           = xfs_file_mmap,
         .open           = xfs_file_open,
+        .flush          = xfs_file_close,
         .release        = xfs_file_release,
         .fsync          = xfs_file_fsync,
 };