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authorDarrick J. Wong <djwong@kernel.org>2024-10-03 08:09:16 -0700
committerChristian Brauner <brauner@kernel.org>2024-10-07 13:51:47 +0200
commit6ef6a0e821d3dad6bf8a5d5508762dba9042c84b (patch)
tree232a6fe656e8d4821decbf14a923d92a3fe7ac26 /fs/iomap
parentb8c4076db5fd24b3be047e033b1098a5366db2fc (diff)
iomap: share iomap_unshare_iter predicate code with fsdax
The predicate code that iomap_unshare_iter uses to decide if it's really needs to unshare a file range mapping should be shared with the fsdax version, because right now they're opencoded and inconsistent. Note that we simplify the predicate logic a bit -- we no longer allow unsharing of inline data mappings, but there aren't any filesystems that allow shared inline data currently. This is a fix in the sense that it should have been ported to fsdax. Fixes: b53fdb215d13 ("iomap: improve shared block detection in iomap_unshare_iter") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/172796813294.1131942.15762084021076932620.stgit@frogsfrogsfrogs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/iomap')
-rw-r--r--fs/iomap/buffered-io.c30
1 files changed, 16 insertions, 14 deletions
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 78ebd265f425..3899169b2cf7 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1309,19 +1309,12 @@ void iomap_file_buffered_write_punch_delalloc(struct inode *inode,
}
EXPORT_SYMBOL_GPL(iomap_file_buffered_write_punch_delalloc);
-static loff_t iomap_unshare_iter(struct iomap_iter *iter)
+bool iomap_want_unshare_iter(const struct iomap_iter *iter)
{
- struct iomap *iomap = &iter->iomap;
- loff_t pos = iter->pos;
- 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.
+ * Don't bother with blocks that are not shared to start with; or
+ * mappings that cannot be shared, such as inline data, 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
@@ -1329,9 +1322,18 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)
* 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)
+ return (iter->iomap.flags & IOMAP_F_SHARED) &&
+ iter->srcmap.type == IOMAP_MAPPED;
+}
+
+static loff_t iomap_unshare_iter(struct iomap_iter *iter)
+{
+ struct iomap *iomap = &iter->iomap;
+ loff_t pos = iter->pos;
+ loff_t length = iomap_length(iter);
+ loff_t written = 0;
+
+ if (!iomap_want_unshare_iter(iter))
return length;
do {