From: Zhang Yi <yi.zhang@xxxxxxxxxx>
Increase i_size in iomap_zero_range() looks not needed, the caller
should handle it. Especially, when truncate partial block, we should
not increase i_size beyond the new EOF here. It dosn't affect xfs and
gfs2 now because they reset the new file size after zero out, it doesn't
matter that a brief increase in i_size. But it will affect ext4 because
it set file size before truncate, so avoid increasing if it's not a
write path.
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
fs/iomap/buffered-io.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index e0c9cede82ee..293ba00e4bc0 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -887,6 +887,7 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
{
const struct iomap *srcmap = iomap_iter_srcmap(iter);
loff_t old_size = iter->inode->i_size;
+ bool update_size = iter->flags & IOMAP_WRITE;
size_t ret;
if (srcmap->type == IOMAP_INLINE) {
@@ -903,13 +904,13 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
* cache. It's up to the file system to write the updated size to disk,
* preferably after I/O completion so that no stale data is exposed.
*/
- if (pos + ret > old_size) {
+ if (update_size && pos + ret > old_size) {
i_size_write(iter->inode, pos + ret);
iter->iomap.flags |= IOMAP_F_SIZE_CHANGED;
}
__iomap_put_folio(iter, pos, ret, folio);
- if (old_size < pos)
+ if (update_size && old_size < pos)
pagecache_isize_extended(iter->inode, old_size, pos);
if (ret < len)
iomap_write_failed(iter->inode, pos + ret, len - ret);
--
2.39.2
