1 files changed, 50 insertions, 13 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 203700278ddb..e33e5e13b95f 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -214,6 +214,43 @@ xfs_ilock_iocb(
 	return 0;
 }
 
+static int
+xfs_ilock_iocb_for_write(
+	struct kiocb		*iocb,
+	unsigned int		*lock_mode)
+{
+	ssize_t			ret;
+	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
+
+	ret = xfs_ilock_iocb(iocb, *lock_mode);
+	if (ret)
+		return ret;
+
+	if (*lock_mode == XFS_IOLOCK_EXCL)
+		return 0;
+	if (!xfs_iflags_test(ip, XFS_IREMAPPING))
+		return 0;
+
+	xfs_iunlock(ip, *lock_mode);
+	*lock_mode = XFS_IOLOCK_EXCL;
+	return xfs_ilock_iocb(iocb, *lock_mode);
+}
+
+static unsigned int
+xfs_ilock_for_write_fault(
+	struct xfs_inode	*ip)
+{
+	/* get a shared lock if no remapping in progress */
+	xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+	if (!xfs_iflags_test(ip, XFS_IREMAPPING))
+		return XFS_MMAPLOCK_SHARED;
+
+	/* wait for remapping to complete */
+	xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+	return XFS_MMAPLOCK_EXCL;
+}
+
 STATIC ssize_t
 xfs_file_dio_read(
 	struct kiocb		*iocb,
@@ -551,7 +588,7 @@ xfs_file_dio_write_aligned(
 	unsigned int		iolock = XFS_IOLOCK_SHARED;
 	ssize_t			ret;
 
-	ret = xfs_ilock_iocb(iocb, iolock);
+	ret = xfs_ilock_iocb_for_write(iocb, &iolock);
 	if (ret)
 		return ret;
 	ret = xfs_file_write_checks(iocb, from, &iolock);
@@ -618,7 +655,7 @@ retry_exclusive:
 		flags = IOMAP_DIO_FORCE_WAIT;
 	}
 
-	ret = xfs_ilock_iocb(iocb, iolock);
+	ret = xfs_ilock_iocb_for_write(iocb, &iolock);
 	if (ret)
 		return ret;
 
@@ -1180,7 +1217,7 @@ xfs_file_remap_range(
 	if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
 		xfs_log_force_inode(dest);
 out_unlock:
-	xfs_iunlock2_io_mmap(src, dest);
+	xfs_iunlock2_remapping(src, dest);
 	if (ret)
 		trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
 	return remapped > 0 ? remapped : ret;
@@ -1328,6 +1365,7 @@ __xfs_filemap_fault(
 	struct inode		*inode = file_inode(vmf->vma->vm_file);
 	struct xfs_inode	*ip = XFS_I(inode);
 	vm_fault_t		ret;
+	unsigned int		lock_mode = 0;
 
 	trace_xfs_filemap_fault(ip, order, write_fault);
 
@@ -1336,25 +1374,24 @@ __xfs_filemap_fault(
 		file_update_time(vmf->vma->vm_file);
 	}
 
+	if (IS_DAX(inode) || write_fault)
+		lock_mode = xfs_ilock_for_write_fault(XFS_I(inode));
+
 	if (IS_DAX(inode)) {
 		pfn_t pfn;
 
-		xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
 		ret = xfs_dax_fault(vmf, order, write_fault, &pfn);
 		if (ret & VM_FAULT_NEEDDSYNC)
 			ret = dax_finish_sync_fault(vmf, order, pfn);
-		xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+	} else if (write_fault) {
+		ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
 	} else {
-		if (write_fault) {
-			xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-			ret = iomap_page_mkwrite(vmf,
-					&xfs_page_mkwrite_iomap_ops);
-			xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-		} else {
-			ret = filemap_fault(vmf);
-		}
+		ret = filemap_fault(vmf);
 	}
 
+	if (lock_mode)
+		xfs_iunlock(XFS_I(inode), lock_mode);
+
 	if (write_fault)
 		sb_end_pagefault(inode->i_sb);
 	return ret;