[PATCH v3 3/7] btrfs: Convert end_compressed_writeback() to use filemap_get_folios()

Vishal Moola (Oracle)
2022-08-24T00:42:58Z

Converted function to use folios throughout. This is in preparation for
the removal of find_get_pages_contig(). Now also supports large folios.

Since we may receive more than nr_pages pages, nr_pages may underflow.
Since nr_pages > 0 is equivalent to index <= end_index, we replaced it
with this check instead.

Also this function does not care about the pages being contiguous so we
can just use filemap_get_folios() to be more efficient.

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
fs/btrfs/compression.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index f4564f32f6d9..e0f8839cdd94 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -8,6 +8,7 @@
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
+#include <linux/pagevec.h>
#include <linux/highmem.h>
#include <linux/kthread.h>
#include <linux/time.h>
@@ -339,8 +340,7 @@ static noinline void end_compressed_writeback(struct inode *inode,
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
unsigned long index = cb->start >> PAGE_SHIFT;
unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_SHIFT;
- struct page *pages[16];
- unsigned long nr_pages = end_index - index + 1;
+ struct folio_batch fbatch;
const int errno = blk_status_to_errno(cb->status);
int i;
int ret;
@@ -348,24 +348,23 @@ static noinline void end_compressed_writeback(struct inode *inode,
if (errno)
mapping_set_error(inode->i_mapping, errno);

- while (nr_pages > 0) {
- ret = find_get_pages_contig(inode->i_mapping, index,
- min_t(unsigned long,
- nr_pages, ARRAY_SIZE(pages)), pages);
- if (ret == 0) {
- nr_pages -= 1;
- index += 1;
- continue;
- }
+ folio_batch_init(&fbatch);
+ while (index <= end_index) {
+ ret = filemap_get_folios(inode->i_mapping, &index, end_index,
+ &fbatch);
+
+ if (ret == 0)
+ return;
+
for (i = 0; i < ret; i++) {
+ struct folio *folio = fbatch.folios[i];
+
if (errno)
- SetPageError(pages[i]);
- btrfs_page_clamp_clear_writeback(fs_info, pages[i],
+ folio_set_error(folio);
+ btrfs_page_clamp_clear_writeback(fs_info, &folio->page,
cb->start, cb->len);
- put_page(pages[i]);
}
- nr_pages -= ret;
- index += ret;
+ folio_batch_release(&fbatch);
}
/* the inode may be gone now */
}
--
2.36.1