1 files changed, 54 insertions, 16 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index a2e1cb8a568b..b101e80f2862 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -847,6 +847,9 @@ xfs_file_fallocate(
         if (error)
                 goto out_unlock;
 
+        xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+        iolock |= XFS_MMAPLOCK_EXCL;
+
         if (mode & FALLOC_FL_PUNCH_HOLE) {
                 error = xfs_free_file_space(ip, offset, len);
                 if (error)
@@ -997,20 +1000,6 @@ xfs_file_mmap(
 }
 
 /*
- * mmap()d file has taken write protection fault and is being made
- * writable. We can set the page state up correctly for a writable
- * page, which means we can do correct delalloc accounting (ENOSPC
- * checking!) and unwritten extent mapping.
- */
-STATIC int
-xfs_vm_page_mkwrite(
-        struct vm_area_struct   *vma,
-        struct vm_fault         *vmf)
-{
-        return block_page_mkwrite(vma, vmf, xfs_get_blocks);
-}
-
-/*
  * This type is designed to indicate the type of offset we would like
  * to search from page cache for xfs_seek_hole_data().
  */
@@ -1385,6 +1374,55 @@ xfs_file_llseek(
         }
 }
 
+/*
+ * Locking for serialisation of IO during page faults. This results in a lock
+ * ordering of:
+ *
+ * mmap_sem (MM)
+ *   i_mmap_lock (XFS - truncate serialisation)
+ *     page_lock (MM)
+ *       i_lock (XFS - extent map serialisation)
+ */
+STATIC int
+xfs_filemap_fault(
+        struct vm_area_struct   *vma,
+        struct vm_fault         *vmf)
+{
+        struct xfs_inode        *ip = XFS_I(vma->vm_file->f_mapping->host);
+        int                     error;
+
+        trace_xfs_filemap_fault(ip);
+
+        xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+        error = filemap_fault(vma, vmf);
+        xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+        return error;
+}
+
+/*
+ * mmap()d file has taken write protection fault and is being made writable. We
+ * can set the page state up correctly for a writable page, which means we can
+ * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
+ * mapping.
+ */
+STATIC int
+xfs_filemap_page_mkwrite(
+        struct vm_area_struct   *vma,
+        struct vm_fault         *vmf)
+{
+        struct xfs_inode        *ip = XFS_I(vma->vm_file->f_mapping->host);
+        int                     error;
+
+        trace_xfs_filemap_page_mkwrite(ip);
+
+        xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+        error = block_page_mkwrite(vma, vmf, xfs_get_blocks);
+        xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+        return error;
+}
+
 const struct file_operations xfs_file_operations = {
         .llseek         = xfs_file_llseek,
         .read           = new_sync_read,
@@ -1417,7 +1455,7 @@ const struct file_operations xfs_dir_file_operations = {
 };
 
 static const struct vm_operations_struct xfs_file_vm_ops = {
-        .fault          = filemap_fault,
+        .fault          = xfs_filemap_fault,
         .map_pages      = filemap_map_pages,
-        .page_mkwrite   = xfs_vm_page_mkwrite,
+        .page_mkwrite   = xfs_filemap_page_mkwrite,
 };