fs/buffer: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for block layer
request flags. Change WRITE into REQ_OP_WRITE. This patch does not change
any functionality since REQ_OP_WRITE == WRITE == 1.
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-47-bvanassche@acm.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

fs/buffer.c

@@ -52,8 +52,8 @@
 #include "internal.h"
 
 static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
-static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
-			 struct writeback_control *wbc);
+static int submit_bh_wbc(enum req_op op, blk_opf_t op_flags,
+			 struct buffer_head *bh, struct writeback_control *wbc);
 
 #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
 
@@ -1716,7 +1716,7 @@ int __block_write_full_page(struct inode *inode, struct page *page,
 	struct buffer_head *bh, *head;
 	unsigned int blocksize, bbits;
 	int nr_underway = 0;
-	int write_flags = wbc_to_write_flags(wbc);
+	blk_opf_t write_flags = wbc_to_write_flags(wbc);
 
 	head = create_page_buffers(page, inode,
 					(1 << BH_Dirty)|(1 << BH_Uptodate));
@@ -2994,8 +2994,8 @@ static void end_bio_bh_io_sync(struct bio *bio)
 	bio_put(bio);
 }
 
-static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
-			 struct writeback_control *wbc)
+static int submit_bh_wbc(enum req_op op, blk_opf_t op_flags,
+			 struct buffer_head *bh, struct writeback_control *wbc)
 {
 	struct bio *bio;
 
@@ -3040,7 +3040,7 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
 	return 0;
 }
 
-int submit_bh(int op, int op_flags, struct buffer_head *bh)
+int submit_bh(enum req_op op, blk_opf_t op_flags, struct buffer_head *bh)
 {
 	return submit_bh_wbc(op, op_flags, bh, NULL);
 }
@@ -3072,7 +3072,8 @@ EXPORT_SYMBOL(submit_bh);
  * All of the buffers must be for the same device, and must also be a
  * multiple of the current approved size for the device.
  */
-void ll_rw_block(int op, int op_flags,  int nr, struct buffer_head *bhs[])
+void ll_rw_block(enum req_op op, blk_opf_t op_flags, int nr,
+		 struct buffer_head *bhs[])
 {
 	int i;
 
@@ -3081,7 +3082,7 @@ void ll_rw_block(int op, int op_flags,  int nr, struct buffer_head *bhs[])
 
 		if (!trylock_buffer(bh))
 			continue;
-		if (op == WRITE) {
+		if (op == REQ_OP_WRITE) {
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
 				get_bh(bh);
@@ -3101,7 +3102,7 @@ void ll_rw_block(int op, int op_flags,  int nr, struct buffer_head *bhs[])
 }
 EXPORT_SYMBOL(ll_rw_block);
 
-void write_dirty_buffer(struct buffer_head *bh, int op_flags)
+void write_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 {
 	lock_buffer(bh);
 	if (!test_clear_buffer_dirty(bh)) {
@@ -3119,7 +3120,7 @@ EXPORT_SYMBOL(write_dirty_buffer);
  * and then start new I/O and then wait upon it.  The caller must have a ref on
  * the buffer_head.
  */
-int __sync_dirty_buffer(struct buffer_head *bh, int op_flags)
+int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags)
 {
 	int ret = 0;
 

include/linux/buffer_head.h

@@ -9,6 +9,7 @@
 #define _LINUX_BUFFER_HEAD_H
 
 #include <linux/types.h>
+#include <linux/blk_types.h>
 #include <linux/fs.h>
 #include <linux/linkage.h>
 #include <linux/pagemap.h>
@@ -201,11 +202,11 @@ struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
 void free_buffer_head(struct buffer_head * bh);
 void unlock_buffer(struct buffer_head *bh);
 void __lock_buffer(struct buffer_head *bh);
-void ll_rw_block(int, int, int, struct buffer_head * bh[]);
+void ll_rw_block(enum req_op, blk_opf_t, int, struct buffer_head * bh[]);
 int sync_dirty_buffer(struct buffer_head *bh);
-int __sync_dirty_buffer(struct buffer_head *bh, int op_flags);
-void write_dirty_buffer(struct buffer_head *bh, int op_flags);
-int submit_bh(int, int, struct buffer_head *);
+int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
+void write_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
+int submit_bh(enum req_op, blk_opf_t, struct buffer_head *);
 void write_boundary_block(struct block_device *bdev,
 			sector_t bblock, unsigned blocksize);
 int bh_uptodate_or_lock(struct buffer_head *bh);