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: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-8-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 620c830dfec4e0df5bbf3f248d0a36efd52bf2ca..1333a0d96f83245999f582c2e54eb58822f527da 100644 (file)
--- 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 @@ retry:
                        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 @@ retry:
                 * 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 @@ retry:
                                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