Unverified Commit 1a61d749 authored by Zhang Yi's avatar Zhang Yi Committed by Christian Brauner
Browse files

iomap: use a new variable to handle the written bytes in iomap_write_iter() 



In iomap_write_iter(), the status variable used to receive the return
value from iomap_write_end() is confusing, replace it with a new written
variable to represent the written bytes in each cycle, no logic changes.

Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-8-yi.zhang@huaweicloud.com


Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 943bc088

fs/iomap/buffered-io.c

+17 −16
Original line number Diff line number Diff line
@@ -889,7 +889,7 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
	loff_t length = iomap_length(iter);

	size_t chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;

	loff_t pos = iter->pos;

	ssize_t written = 0;

	ssize_t total_written = 0;

	long status = 0;

	struct address_space *mapping = iter->inode->i_mapping;

	unsigned int bdp_flags = (iter->flags & IOMAP_NOWAIT) ? BDP_ASYNC : 0;
@@ -900,6 +900,7 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
		size_t offset;		/* Offset into folio */

		size_t bytes;		/* Bytes to write to folio */

		size_t copied;		/* Bytes copied from user */

		size_t written;		/* Bytes have been written */



		bytes = iov_iter_count(i);

retry:
@@ -944,7 +945,7 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
			flush_dcache_folio(folio);



		copied = copy_folio_from_iter_atomic(folio, offset, bytes, i);

		status = iomap_write_end(iter, pos, bytes, copied, folio);

		written = iomap_write_end(iter, pos, bytes, copied, folio);



		/*

		 * Update the in-memory inode size after copying the data into
@@ -954,22 +955,22 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
		 * unlock and release the folio.

		 */

		old_size = iter->inode->i_size;

		if (pos + status > old_size) {

			i_size_write(iter->inode, pos + status);

		if (pos + written > old_size) {

			i_size_write(iter->inode, pos + written);

			iter->iomap.flags |= IOMAP_F_SIZE_CHANGED;

		}

		__iomap_put_folio(iter, pos, status, folio);

		__iomap_put_folio(iter, pos, written, folio);



		if (old_size < pos)

			pagecache_isize_extended(iter->inode, old_size, pos);

		if (status < bytes)

			iomap_write_failed(iter->inode, pos + status,

					   bytes - status);

		if (unlikely(copied != status))

			iov_iter_revert(i, copied - status);

		if (written < bytes)

			iomap_write_failed(iter->inode, pos + written,

					   bytes - written);

		if (unlikely(copied != written))

			iov_iter_revert(i, copied - written);



		cond_resched();

		if (unlikely(status == 0)) {

		if (unlikely(written == 0)) {

			/*

			 * A short copy made iomap_write_end() reject the

			 * thing entirely.  Might be memory poisoning
@@ -983,17 +984,17 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) 
				goto retry;

			}

		} else {

			pos += status;

			written += status;

			length -= status;

			pos += written;

			total_written += written;

			length -= written;

		}

	} while (iov_iter_count(i) && length);



	if (status == -EAGAIN) {

		iov_iter_revert(i, written);

		iov_iter_revert(i, total_written);

		return -EAGAIN;

	}

	return written ? written : status;

	return total_written ? total_written : status;

}



ssize_t