The patch titled
Subject: buffer: convert block_truncate_page() to use a folio
has been added to the -mm mm-unstable branch. Its filename is
buffer-convert-block_truncate_page-to-use-a-folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/buffer-convert-block_truncate_page-to-use-a-folio.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: buffer: convert block_truncate_page() to use a folio
Date: Mon, 12 Jun 2023 22:01:41 +0100
Support large folios in block_truncate_page() and avoid three hidden calls
to compound_head().
Link: https://lkml.kernel.org/r/20230612210141.730128-15-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Bob Peterson <rpeterso@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
--- a/fs/buffer.c~buffer-convert-block_truncate_page-to-use-a-folio
+++ a/fs/buffer.c
@@ -2598,17 +2598,16 @@ int block_truncate_page(struct address_s
loff_t from, get_block_t *get_block)
{
pgoff_t index = from >> PAGE_SHIFT;
- unsigned offset = from & (PAGE_SIZE-1);
unsigned blocksize;
sector_t iblock;
- unsigned length, pos;
+ size_t offset, length, pos;
struct inode *inode = mapping->host;
- struct page *page;
+ struct folio *folio;
struct buffer_head *bh;
int err = 0;
blocksize = i_blocksize(inode);
- length = offset & (blocksize - 1);
+ length = from & (blocksize - 1);
/* Block boundary? Nothing to do */
if (!length)
@@ -2617,15 +2616,18 @@ int block_truncate_page(struct address_s
length = blocksize - length;
iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits);
- page = grab_cache_page(mapping, index);
- if (!page)
+ folio = filemap_grab_folio(mapping, index);
+ if (!folio)
return -ENOMEM;
- if (!page_has_buffers(page))
- create_empty_buffers(page, blocksize, 0);
+ bh = folio_buffers(folio);
+ if (!bh) {
+ folio_create_empty_buffers(folio, blocksize, 0);
+ bh = folio_buffers(folio);
+ }
/* Find the buffer that contains "offset" */
- bh = page_buffers(page);
+ offset = offset_in_folio(folio, from);
pos = blocksize;
while (offset >= pos) {
bh = bh->b_this_page;
@@ -2644,7 +2646,7 @@ int block_truncate_page(struct address_s
}
/* Ok, it's mapped. Make sure it's up-to-date */
- if (PageUptodate(page))
+ if (folio_test_uptodate(folio))
set_buffer_uptodate(bh);
if (!buffer_uptodate(bh) && !buffer_delay(bh) && !buffer_unwritten(bh)) {
@@ -2654,12 +2656,12 @@ int block_truncate_page(struct address_s
goto unlock;
}
- zero_user(page, offset, length);
+ folio_zero_range(folio, offset, length);
mark_buffer_dirty(bh);
unlock:
- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
return err;
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
gfs2-use-a-folio-inside-gfs2_jdata_writepage.patch
gfs2-pass-a-folio-to-__gfs2_jdata_write_folio.patch
gfs2-convert-gfs2_write_jdata_page-to-gfs2_write_jdata_folio.patch
buffer-convert-__block_write_full_page-to-__block_write_full_folio.patch
gfs2-support-ludicrously-large-folios-in-gfs2_trans_add_databufs.patch
buffer-make-block_write_full_page-handle-large-folios-correctly.patch
buffer-convert-block_page_mkwrite-to-use-a-folio.patch
buffer-convert-__block_commit_write-to-take-a-folio.patch
buffer-convert-page_zero_new_buffers-to-folio_zero_new_buffers.patch
buffer-convert-grow_dev_page-to-use-a-folio.patch
buffer-convert-init_page_buffers-to-folio_init_buffers.patch
buffer-convert-link_dev_buffers-to-take-a-folio.patch
buffer-use-a-folio-in-__find_get_block_slow.patch
buffer-convert-block_truncate_page-to-use-a-folio.patch
