[PATCH v5 7/9] iomap: use a new variable to handle the written bytes in iomap_write_iter()

Zhang Yi
2024-04-25T13:23:09Z

From: Zhang Yi <yi.zhang@huawei.com>

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: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
fs/iomap/buffered-io.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 63d94189e568..854fa3d4b1c8 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -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
--
2.39.2