iomap: resample iter->pos after iomap_write_begin() calls

In preparation for removing the pos parameter, push the local pos
assignment down after calls to iomap_write_begin().

Signed-off-by: Brian Foster <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

Author: Brian Foster

fs/iomap/buffered-io.c

@@ -920,11 +920,11 @@ static int iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i)
 		size_t bytes;		/* Bytes to write to folio */
 		size_t copied;		/* Bytes copied from user */
 		u64 written;		/* Bytes have been written */
-		loff_t pos = iter->pos;
+		loff_t pos;
 
 		bytes = iov_iter_count(i);
 retry:
-		offset = pos & (chunk - 1);
+		offset = iter->pos & (chunk - 1);
 		bytes = min(chunk - offset, bytes);
 		status = balance_dirty_pages_ratelimited_flags(mapping,
 							       bdp_flags);
@@ -949,13 +949,14 @@ static int iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i)
 			break;
 		}
 
-		status = iomap_write_begin(iter, pos, bytes, &folio);
+		status = iomap_write_begin(iter, iter->pos, bytes, &folio);
 		if (unlikely(status)) {
-			iomap_write_failed(iter->inode, pos, bytes);
+			iomap_write_failed(iter->inode, iter->pos, bytes);
 			break;
 		}
 		if (iter->iomap.flags & IOMAP_F_STALE)
 			break;
+		pos = iter->pos;
 
 		offset = offset_in_folio(folio, pos);
 		if (bytes > folio_size(folio) - offset)
@@ -1276,15 +1277,16 @@ static int iomap_unshare_iter(struct iomap_iter *iter)
 	do {
 		struct folio *folio;
 		size_t offset;
-		loff_t pos = iter->pos;
+		loff_t pos;
 		bool ret;
 
 		bytes = min_t(u64, SIZE_MAX, bytes);
-		status = iomap_write_begin(iter, pos, bytes, &folio);
+		status = iomap_write_begin(iter, iter->pos, bytes, &folio);
 		if (unlikely(status))
 			return status;
 		if (iomap->flags & IOMAP_F_STALE)
 			break;
+		pos = iter->pos;
 
 		offset = offset_in_folio(folio, pos);
 		if (bytes > folio_size(folio) - offset)
@@ -1351,15 +1353,16 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero)
 	do {
 		struct folio *folio;
 		size_t offset;
-		loff_t pos = iter->pos;
+		loff_t pos;
 		bool ret;
 
 		bytes = min_t(u64, SIZE_MAX, bytes);
-		status = iomap_write_begin(iter, pos, bytes, &folio);
+		status = iomap_write_begin(iter, iter->pos, bytes, &folio);
 		if (status)
 			return status;
 		if (iter->iomap.flags & IOMAP_F_STALE)
 			break;
+		pos = iter->pos;
 
 		/* warn about zeroing folios beyond eof that won't write back */
 		WARN_ON_ONCE(folio_pos(folio) > iter->inode->i_size);