+ ext4-convert-to-folio_create_empty_buffers.patch added to mm-unstable branch

+ ext4-convert-to-folio_create_empty_buffers.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: ext4: convert to folio_create_empty_buffers
has been added to the -mm mm-unstable branch.  Its filename is
     ext4-convert-to-folio_create_empty_buffers.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ext4-convert-to-folio_create_empty_buffers.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@infradead.org>
Subject: ext4: convert to folio_create_empty_buffers
Date: Mon, 16 Oct 2023 21:10:51 +0100

Remove an unnecessary folio->page->folio conversion and take advantage of
the new return value from folio_create_empty_buffers().

Link: https://lkml.kernel.org/r/20231016201114.1928083-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ext4/inode.c       |   14 +++++---------
 fs/ext4/move_extent.c |   11 +++++------
 2 files changed, 10 insertions(+), 15 deletions(-)

--- a/fs/ext4/inode.c~ext4-convert-to-folio_create_empty_buffers
+++ a/fs/ext4/inode.c
@@ -1020,10 +1020,8 @@ static int ext4_block_write_begin(struct
 	BUG_ON(from > to);
 
 	head = folio_buffers(folio);
-	if (!head) {
-		create_empty_buffers(&folio->page, blocksize, 0);
-		head = folio_buffers(folio);
-	}
+	if (!head)
+		head = folio_create_empty_buffers(folio, blocksize, 0);
 	bbits = ilog2(blocksize);
 	block = (sector_t)folio->index << (PAGE_SHIFT - bbits);
 
@@ -1153,7 +1151,7 @@ retry_grab:
 	 * starting the handle.
 	 */
 	if (!folio_buffers(folio))
-		create_empty_buffers(&folio->page, inode->i_sb->s_blocksize, 0);
+		folio_create_empty_buffers(folio, inode->i_sb->s_blocksize, 0);
 
 	folio_unlock(folio);
 
@@ -3643,10 +3641,8 @@ static int __ext4_block_zero_page_range(
 	iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
 
 	bh = folio_buffers(folio);
-	if (!bh) {
-		create_empty_buffers(&folio->page, blocksize, 0);
-		bh = folio_buffers(folio);
-	}
+	if (!bh)
+		bh = folio_create_empty_buffers(folio, blocksize, 0);
 
 	/* Find the buffer that contains "offset" */
 	pos = blocksize;
--- a/fs/ext4/move_extent.c~ext4-convert-to-folio_create_empty_buffers
+++ a/fs/ext4/move_extent.c
@@ -183,10 +183,8 @@ mext_page_mkuptodate(struct folio *folio
 
 	blocksize = i_blocksize(inode);
 	head = folio_buffers(folio);
-	if (!head) {
-		create_empty_buffers(&folio->page, blocksize, 0);
-		head = folio_buffers(folio);
-	}
+	if (!head)
+		head = folio_create_empty_buffers(folio, blocksize, 0);
 
 	block = (sector_t)folio->index << (PAGE_SHIFT - inode->i_blkbits);
 	for (bh = head, block_start = 0; bh != head || !block_start;
@@ -380,9 +378,10 @@ data_copy:
 	}
 	/* Perform all necessary steps similar write_begin()/write_end()
 	 * but keeping in mind that i_size will not change */
-	if (!folio_buffers(folio[0]))
-		create_empty_buffers(&folio[0]->page, 1 << orig_inode->i_blkbits, 0);
 	bh = folio_buffers(folio[0]);
+	if (!bh)
+		bh = folio_create_empty_buffers(folio[0],
+				1 << orig_inode->i_blkbits, 0);
 	for (i = 0; i < data_offset_in_page; i++)
 		bh = bh->b_this_page;
 	for (i = 0; i < block_len_in_page; i++) {
_

Patches currently in -mm which might be from willy@infradead.org are

mm-make-lock_folio_maybe_drop_mmap-vma-lock-aware.patch
mm-call-wp_page_copy-under-the-vma-lock.patch
mm-handle-shared-faults-under-the-vma-lock.patch
mm-handle-cow-faults-under-the-vma-lock.patch
mm-handle-read-faults-under-the-vma-lock.patch
mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch
iomap-hold-state_lock-over-call-to-ifs_set_range_uptodate.patch
iomap-protect-read_bytes_pending-with-the-state_lock.patch
mm-add-folio_end_read.patch
ext4-use-folio_end_read.patch
buffer-use-folio_end_read.patch
iomap-use-folio_end_read.patch
bitops-add-xor_unlock_is_negative_byte.patch
alpha-implement-xor_unlock_is_negative_byte.patch
m68k-implement-xor_unlock_is_negative_byte.patch
mips-implement-xor_unlock_is_negative_byte.patch
powerpc-implement-arch_xor_unlock_is_negative_byte-on-32-bit.patch
riscv-implement-xor_unlock_is_negative_byte.patch
s390-implement-arch_xor_unlock_is_negative_byte.patch
mm-delete-checks-for-xor_unlock_is_negative_byte.patch
mm-add-folio_xor_flags_has_waiters.patch
mm-make-__end_folio_writeback-return-void.patch
mm-use-folio_xor_flags_has_waiters-in-folio_end_writeback.patch
filemap-remove-use-of-wait-bookmarks.patch
sched-remove-wait-bookmarks.patch
buffer-return-bool-from-grow_dev_folio.patch
buffer-make-folio_create_empty_buffers-return-a-buffer_head.patch
mpage-convert-map_buffer_to_folio-to-folio_create_empty_buffers.patch
ext4-convert-to-folio_create_empty_buffers.patch
buffer-add-get_nth_bh.patch
gfs2-convert-inode-unstuffing-to-use-a-folio.patch
gfs2-convert-gfs2_getbuf-to-folios.patch
gfs2-convert-gfs2_getjdatabuf-to-use-a-folio.patch
gfs2-convert-gfs2_write_buf_to_page-to-use-a-folio.patch
nilfs2-convert-nilfs_mdt_freeze_buffer-to-use-a-folio.patch
nilfs2-convert-nilfs_grab_buffer-to-use-a-folio.patch
nilfs2-convert-nilfs_copy_page-to-nilfs_copy_folio.patch
nilfs2-convert-nilfs_mdt_forget_block-to-use-a-folio.patch
nilfs2-convert-nilfs_mdt_get_frozen_buffer-to-use-a-folio.patch
nilfs2-remove-nilfs_page_get_nth_block.patch
nilfs2-convert-nilfs_lookup_dirty_data_buffers-to-use-folio_create_empty_buffers.patch
ntfs-convert-ntfs_read_block-to-use-a-folio.patch
ntfs-convert-ntfs_writepage-to-use-a-folio.patch
ntfs-convert-ntfs_prepare_pages_for_non_resident_write-to-folios.patch
ntfs3-convert-ntfs_zero_range-to-use-a-folio.patch
ocfs2-convert-ocfs2_map_page_blocks-to-use-a-folio.patch
reiserfs-convert-writepage-to-use-a-folio.patch
ufs-add-ufs_get_locked_folio-and-ufs_put_locked_folio.patch
ufs-use-ufs_get_locked_folio-in-ufs_alloc_lastblock.patch
ufs-convert-ufs_change_blocknr-to-use-folios.patch
ufs-remove-ufs_get_locked_page.patch
buffer-remove-folio_create_empty_buffers.patch