linux-ext4 - [PATCH 5/7] ext2: Convert to buffered_write

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Message-ID: <20240528164829.2105447-6-willy@infradead.org>
Date: Tue, 28 May 2024 17:48:26 +0100
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: Christoph Hellwig <hch@....de>
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
	linux-fsdevel@...r.kernel.org,
	linux-ext4@...r.kernel.org
Subject: [PATCH 5/7] ext2: Convert to buffered_write_operations

Move write_begin and write_end from the address_space_operations to
the new buffered_write_operations.  Removes a number of hidden calls
to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 fs/ext2/ext2.h  |  1 +
 fs/ext2/file.c  |  4 ++--
 fs/ext2/inode.c | 55 ++++++++++++++++++++++++++-----------------------
 fs/ext2/namei.c |  2 +-
 4 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index f38bdd46e4f7..89b498c81f18 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -784,6 +784,7 @@ extern const struct file_operations ext2_file_operations;
 extern void ext2_set_file_ops(struct inode *inode);
 extern const struct address_space_operations ext2_aops;
 extern const struct iomap_ops ext2_iomap_ops;
+extern const struct buffered_write_operations ext2_bw_ops;
 
 /* namei.c */
 extern const struct inode_operations ext2_dir_inode_operations;
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 10b061ac5bc0..108e8d2e9654 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -252,7 +252,7 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 		iocb->ki_flags &= ~IOCB_DIRECT;
 		pos = iocb->ki_pos;
-		status = generic_perform_write(iocb, from);
+		status = filemap_perform_write(iocb, from, &ext2_bw_ops, NULL);
 		if (unlikely(status < 0)) {
 			ret = status;
 			goto out_unlock;
@@ -299,7 +299,7 @@ static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (iocb->ki_flags & IOCB_DIRECT)
 		return ext2_dio_write_iter(iocb, from);
 
-	return generic_file_write_iter(iocb, from);
+	return filemap_write_iter(iocb, from, &ext2_bw_ops, NULL);
 }
 
 static int ext2_file_open(struct inode *inode, struct file *filp)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 0caa1650cee8..a89525d08aa3 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -914,30 +914,6 @@ static void ext2_readahead(struct readahead_control *rac)
 	mpage_readahead(rac, ext2_get_block);
 }
 
-static int
-ext2_write_begin(struct file *file, struct address_space *mapping,
-		loff_t pos, unsigned len, struct page **pagep, void **fsdata)
-{
-	int ret;
-
-	ret = block_write_begin(mapping, pos, len, pagep, ext2_get_block);
-	if (ret < 0)
-		ext2_write_failed(mapping, pos + len);
-	return ret;
-}
-
-static int ext2_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	int ret;
-
-	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
-	if (ret < len)
-		ext2_write_failed(mapping, pos + len);
-	return ret;
-}
-
 static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
 {
 	return generic_block_bmap(mapping,block,ext2_get_block);
@@ -962,8 +938,6 @@ const struct address_space_operations ext2_aops = {
 	.invalidate_folio	= block_invalidate_folio,
 	.read_folio		= ext2_read_folio,
 	.readahead		= ext2_readahead,
-	.write_begin		= ext2_write_begin,
-	.write_end		= ext2_write_end,
 	.bmap			= ext2_bmap,
 	.writepages		= ext2_writepages,
 	.migrate_folio		= buffer_migrate_folio,
@@ -976,6 +950,35 @@ static const struct address_space_operations ext2_dax_aops = {
 	.dirty_folio		= noop_dirty_folio,
 };
 
+static struct folio *ext2_write_begin(struct file *file,
+		struct address_space *mapping, loff_t pos, size_t len,
+		void **fsdata)
+{
+	struct folio *folio;
+
+	folio = buffer_write_begin(mapping, pos, len, ext2_get_block);
+
+	if (IS_ERR(folio))
+		ext2_write_failed(mapping, pos + len);
+	return folio;
+}
+
+static size_t ext2_write_end(struct file *file, struct address_space *mapping,
+		loff_t pos, size_t len, size_t copied, struct folio *folio,
+		void **fsdata)
+{
+	size_t ret = buffer_write_end(file, mapping, pos, len, copied, folio);
+
+	if (ret < len)
+		ext2_write_failed(mapping, pos + len);
+	return ret;
+}
+
+const struct buffered_write_operations ext2_bw_ops = {
+	.write_begin		= ext2_write_begin,
+	.write_end		= ext2_write_end,
+};
+
 /*
  * Probably it should be a library function... search for first non-zero word
  * or memcmp with zero_page, whatever is better for particular architecture.
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 8346ab9534c1..a0edb11be826 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -179,7 +179,7 @@ static int ext2_symlink (struct mnt_idmap * idmap, struct inode * dir,
 		inode->i_op = &ext2_symlink_inode_operations;
 		inode_nohighmem(inode);
 		inode->i_mapping->a_ops = &ext2_aops;
-		err = page_symlink(inode, symname, l);
+		err = filemap_symlink(inode, symname, l, &ext2_bw_ops, NULL);
 		if (err)
 			goto out_fail;
 	} else {
-- 
2.43.0