Linux-libre 4.5-gnu

1 files changed, 23 insertions, 15 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index f5392ab2d..52883ac3c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -55,7 +55,7 @@ xfs_rw_ilock(
 	int			type)
 {
 	if (type & XFS_IOLOCK_EXCL)
-		mutex_lock(&VFS_I(ip)->i_mutex);
+		inode_lock(VFS_I(ip));
 	xfs_ilock(ip, type);
 }
 
@@ -66,7 +66,7 @@ xfs_rw_iunlock(
 {
 	xfs_iunlock(ip, type);
 	if (type & XFS_IOLOCK_EXCL)
-		mutex_unlock(&VFS_I(ip)->i_mutex);
+		inode_unlock(VFS_I(ip));
 }
 
 static inline void
@@ -76,7 +76,7 @@ xfs_rw_ilock_demote(
 {
 	xfs_ilock_demote(ip, type);
 	if (type & XFS_IOLOCK_EXCL)
-		mutex_unlock(&VFS_I(ip)->i_mutex);
+		inode_unlock(VFS_I(ip));
 }
 
 /*
@@ -402,19 +402,26 @@ xfs_file_splice_read(
 	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
 		return -EIO;
 
-	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
-
 	trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
 
-	/* for dax, we need to avoid the page cache */
-	if (IS_DAX(VFS_I(ip)))
-		ret = default_file_splice_read(infilp, ppos, pipe, count, flags);
-	else
-		ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
-	if (ret > 0)
-		XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
+	/*
+	 * DAX inodes cannot ues the page cache for splice, so we have to push
+	 * them through the VFS IO path. This means it goes through
+	 * ->read_iter, which for us takes the XFS_IOLOCK_SHARED. Hence we
+	 * cannot lock the splice operation at this level for DAX inodes.
+	 */
+	if (IS_DAX(VFS_I(ip))) {
+		ret = default_file_splice_read(infilp, ppos, pipe, count,
+					       flags);
+		goto out;
+	}
 
+	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+	ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
 	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+out:
+	if (ret > 0)
+		XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
 	return ret;
 }
 
@@ -1603,9 +1610,8 @@ xfs_filemap_pmd_fault(
 /*
  * pfn_mkwrite was originally inteneded to ensure we capture time stamp
  * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we open-code dax_pfn_mkwrite()
- * here and cycle the XFS_MMAPLOCK_SHARED to ensure we serialise the fault
- * barrier in place.
+ * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
+ * to ensure we serialise the fault barrier in place.
  */
 static int
 xfs_filemap_pfn_mkwrite(
@@ -1628,6 +1634,8 @@ xfs_filemap_pfn_mkwrite(
 	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	if (vmf->pgoff >= size)
 		ret = VM_FAULT_SIGBUS;
+	else if (IS_DAX(inode))
+		ret = dax_pfn_mkwrite(vma, vmf);
 	xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
 	sb_end_pagefault(inode->i_sb);
 	return ret;