Merge tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull iomap fixes from Christian Brauner:
 "Fixes for iomap to prevent data corruption bugs in the fallocate
  unshare range implementation of fsdax and a small cleanup to turn
  iomap_want_unshare_iter() into an inline function"

* tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
  iomap: turn iomap_want_unshare_iter into an inline function
  fsdax: dax_unshare_iter needs to copy entire blocks
  fsdax: remove zeroing code from dax_unshare_iter
  iomap: share iomap_unshare_iter predicate code with fsdax
  xfs: don't allocate COW extents when unsharing a hole

1 files changed, 1 insertions, 16 deletions

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index aa587b2142e2..ef0b68bccbb6 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1277,22 +1277,7 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)
 	loff_t length = iomap_length(iter);
 	loff_t written = 0;
 
-	/* Don't bother with blocks that are not shared to start with. */
-	if (!(iomap->flags & IOMAP_F_SHARED))
-		return length;
-
-	/*
-	 * Don't bother with delalloc reservations, holes or unwritten extents.
-	 *
-	 * Note that we use srcmap directly instead of iomap_iter_srcmap as
-	 * unsharing requires providing a separate source map, and the presence
-	 * of one is a good indicator that unsharing is needed, unlike
-	 * IOMAP_F_SHARED which can be set for any data that goes into the COW
-	 * fork for XFS.
-	 */
-	if (iter->srcmap.type == IOMAP_HOLE ||
-	    iter->srcmap.type == IOMAP_DELALLOC ||
-	    iter->srcmap.type == IOMAP_UNWRITTEN)
+	if (!iomap_want_unshare_iter(iter))
 		return length;
 
 	do {