btrfs has a special fixup for pages that are marked dirty without having
space reserved for them. But the place where is is run means it can't
work for I/O that isn't kicked off inline from __extent_writepage, most
notable compressed I/O and I/O to zoned file systems.
Move the fixup earlier based on not findining any delalloc range in the
I/O tree to cover this case as well instead of relying on the fairly
obscure fallthrough behavior that calls __extent_write_page_io even when
no delalloc space was found.
Fixes: c8b978188c9a ("Btrfs: Add zlib compression support")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/btrfs/extent_io.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2ae3badaf36df6..d8185582b9f4b0 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1153,6 +1153,7 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
u64 delalloc_start = page_start;
u64 delalloc_end = page_end;
u64 delalloc_to_write = 0;
+ bool found_delalloc = false;
int ret = 0;
while (delalloc_start < page_end) {
@@ -1169,6 +1170,22 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
return ret;
delalloc_start = delalloc_end + 1;
+ found_delalloc = true;
+ }
+
+ /*
+ * If we did not find any delalloc range in the io_tree, this must be
+ * the rare case of dirtying pages through get_user_pages without
+ * calling into ->page_mkwrite.
+ * While these are in the process of being fixed by switching to
+ * pin_user_pages, some are still around and need to be worked around
+ * by creating a delalloc reservation in a fixup worker, and waiting
+ * us to be called again with that reservation.
+ */
+ if (!found_delalloc && btrfs_writepage_cow_fixup(page)) {
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 1;
}
/*
@@ -1274,14 +1291,6 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
int ret = 0;
int nr = 0;
- ret = btrfs_writepage_cow_fixup(page);
- if (ret) {
- /* Fixup worker will requeue */
- redirty_page_for_writepage(bio_ctrl->wbc, page);
- unlock_page(page);
- return 1;
- }
-
bio_ctrl->end_io_func = end_bio_extent_writepage;
while (cur <= end) {
u32 len = end - cur + 1;
@@ -1421,9 +1430,6 @@ static int __extent_writepage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl
goto done;
ret = __extent_writepage_io(BTRFS_I(inode), page, bio_ctrl, i_size, &nr);
- if (ret == 1)
- return 0;
-
bio_ctrl->wbc->nr_to_write--;
done:
@@ -2176,8 +2182,6 @@ void extent_write_locked_range(struct inode *inode, struct page *locked_page,
ret = __extent_writepage_io(BTRFS_I(inode), page, &bio_ctrl,
i_size, &nr);
- if (ret == 1)
- goto next_page;
/* Make sure the mapping tag for page dirty gets cleared. */
if (nr == 0) {
@@ -2193,7 +2197,6 @@ void extent_write_locked_range(struct inode *inode, struct page *locked_page,
btrfs_page_unlock_writer(fs_info, page, cur, cur_len);
if (ret < 0)
found_error = true;
-next_page:
put_page(page);
cur = cur_end + 1;
}
--
2.39.2
