1 files changed, 64 insertions, 20 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index f63aeddd31d5..c203839cd5be 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -397,7 +397,8 @@ STATIC int				/* error (positive) */
 xfs_zero_last_block(
 	struct xfs_inode	*ip,
 	xfs_fsize_t		offset,
-	xfs_fsize_t		isize)
+	xfs_fsize_t		isize,
+	bool			*did_zeroing)
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	xfs_fileoff_t		last_fsb = XFS_B_TO_FSBT(mp, isize);
@@ -425,6 +426,7 @@ xfs_zero_last_block(
 	zero_len = mp->m_sb.sb_blocksize - zero_offset;
 	if (isize + zero_len > offset)
 		zero_len = offset - isize;
+	*did_zeroing = true;
 	return xfs_iozero(ip, isize, zero_len);
 }
 
@@ -443,7 +445,8 @@ int					/* error (positive) */
 xfs_zero_eof(
 	struct xfs_inode	*ip,
 	xfs_off_t		offset,		/* starting I/O offset */
-	xfs_fsize_t		isize)		/* current inode size */
+	xfs_fsize_t		isize,		/* current inode size */
+	bool			*did_zeroing)
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	xfs_fileoff_t		start_zero_fsb;
@@ -465,7 +468,7 @@ xfs_zero_eof(
 	 * We only zero a part of that block so it is handled specially.
 	 */
 	if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
-		error = xfs_zero_last_block(ip, offset, isize);
+		error = xfs_zero_last_block(ip, offset, isize, did_zeroing);
 		if (error)
 			return error;
 	}
@@ -525,6 +528,7 @@ xfs_zero_eof(
 		if (error)
 			return error;
 
+		*did_zeroing = true;
 		start_zero_fsb = imap.br_startoff + imap.br_blockcount;
 		ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
 	}
@@ -567,13 +571,15 @@ restart:
 	 * having to redo all checks before.
 	 */
 	if (*pos > i_size_read(inode)) {
+		bool	zero = false;
+
 		if (*iolock == XFS_IOLOCK_SHARED) {
 			xfs_rw_iunlock(ip, *iolock);
 			*iolock = XFS_IOLOCK_EXCL;
 			xfs_rw_ilock(ip, *iolock);
 			goto restart;
 		}
-		error = xfs_zero_eof(ip, *pos, i_size_read(inode));
+		error = xfs_zero_eof(ip, *pos, i_size_read(inode), &zero);
 		if (error)
 			return error;
 	}
@@ -846,6 +852,9 @@ 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)
@@ -1028,20 +1037,6 @@ 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().
  */
@@ -1416,6 +1411,55 @@ 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,
@@ -1448,7 +1492,7 @@ 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,
 };