Merge tag 'vfs-7.2-rc1.bh' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull buffer_head updates from Christian Brauner:
 "This removes b_end_io from struct buffer_head.

  Instead of setting bio->bi_end_io to end_bio_bh_io_sync() which then
  calls bh->b_end_io(), the new bh_submit() and __bh_submit() interfaces
  set bio->bi_end_io to the appropriate completion handler directly,
  replacing two indirect function calls in the completion path with one.
  It is also one fewer function pointer in the middle of a writable data
  structure that can be corrupted, it shrinks struct buffer_head from
  104 to 96 bytes allowing roughly 7% more buffer_heads to be cached in
  the same amount of memory, and it removes some atomic operations as
  the buffer refcount is no longer incremented before calling the end_io
  handler.

  All in-tree users (fs/buffer.c itself, ext4, jbd2, ocfs2, gfs2,
  nilfs2, and md-bitmap) are converted, and submit_bh(),
  mark_buffer_async_write(), and end_buffer_write_sync() are removed"

* tag 'vfs-7.2-rc1.bh' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (34 commits)
  buffer: Remove end_buffer_write_sync()
  buffer: Change calling convention for end_buffer_read_sync()
  buffer: Remove b_end_io
  buffer: Remove submit_bh()
  md-bitmap: Convert read_file_page and write_file_page to bh_submit()
  nilfs2: Convert nilfs_mdt_submit_block to bh_submit()
  nilfs2: Convert nilfs_gccache_submit_read_data to bh_submit()
  nilfs2: Convert nilfs_btnode_submit_block to bh_submit()
  buffer: Remove mark_buffer_async_write()
  gfs2: Convert gfs2_aspace_write_folio to bh_submit()
  gfs2: Remove use of b_end_io in gfs2_meta_read_endio()
  gfs2: Convert gfs2_dir_readahead to bh_submit()
  gfs2: Convert gfs2_metapath_ra to bh_submit()
  ocfs2: Convert ocfs2_write_super_or_backup to bh_submit()
  ocfs2: Convert ocfs2_read_blocks to bh_submit()
  ocfs2: Convert ocfs2_read_block to bh_submit()
  ocfs2: Convert ocfs2_write_block to bh_submit()
  jbd2: Convert jbd2_write_superblock() to bh_submit()
  jbd2: Convert journal commit to bh_submit()
  ext4: Convert ext4_commit_super() to bh_submit()
  ...

2 files changed, 17 insertions, 16 deletions

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 028b9ca8ce52..7d778fe1c47c 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -502,6 +502,18 @@ static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index,
 static void md_bitmap_file_kick(struct bitmap *bitmap);
 
 #ifdef CONFIG_MD_BITMAP_FILE
+static void end_bitmap_write(struct bio *bio)
+{
+	struct buffer_head *bh;
+	bool uptodate = bio_endio_bh(bio, &bh);
+	struct bitmap *bitmap = bh->b_private;
+
+	if (!uptodate)
+		set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
+	if (atomic_dec_and_test(&bitmap->pending_writes))
+		wake_up(&bitmap->write_wait);
+}
+
 static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
 {
 	struct buffer_head *bh = page_buffers(page);
@@ -510,7 +522,7 @@ static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
 		atomic_inc(&bitmap->pending_writes);
 		set_buffer_locked(bh);
 		set_buffer_mapped(bh);
-		submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
+		bh_submit(bh, REQ_OP_WRITE | REQ_SYNC, end_bitmap_write);
 		bh = bh->b_this_page;
 	}
 
@@ -519,16 +531,6 @@ static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
 			   atomic_read(&bitmap->pending_writes) == 0);
 }
 
-static void end_bitmap_write(struct buffer_head *bh, int uptodate)
-{
-	struct bitmap *bitmap = bh->b_private;
-
-	if (!uptodate)
-		set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
-	if (atomic_dec_and_test(&bitmap->pending_writes))
-		wake_up(&bitmap->write_wait);
-}
-
 static void free_buffers(struct page *page)
 {
 	struct buffer_head *bh;
@@ -592,12 +594,11 @@ static int read_file_page(struct file *file, unsigned long index,
 			else
 				count -= blocksize;
 
-			bh->b_end_io = end_bitmap_write;
 			bh->b_private = bitmap;
 			atomic_inc(&bitmap->pending_writes);
 			set_buffer_locked(bh);
 			set_buffer_mapped(bh);
-			submit_bh(REQ_OP_READ, bh);
+			bh_submit(bh, REQ_OP_READ, end_bitmap_write);
 		}
 		blk_cur++;
 		bh = bh->b_this_page;
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 1c7b710fc9c1..1dfa60a41d91 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -38,7 +38,7 @@
  *  Clean -> Dirty  - on compute_parity to satisfy write/sync (RECONSTRUCT or RMW)
  *
  * The Want->Empty, Want->Clean, Dirty->Clean, transitions
- * all happen in b_end_io at interrupt time.
+ * all happen in end_io at interrupt time.
  * Each sets the Uptodate bit before releasing the Lock bit.
  * This leaves one multi-stage transition:
  *    Want->Dirty->Clean
@@ -64,7 +64,7 @@
  * together, but we are not guaranteed of that so we allow for more.
  *
  * If a buffer is on the read list when the associated cache buffer is
- * Uptodate, the data is copied into the read buffer and it's b_end_io
+ * Uptodate, the data is copied into the read buffer and it's end_io
  * routine is called.  This may happen in the end_request routine only
  * if the buffer has just successfully been read.  end_request should
  * remove the buffers from the list and then set the Uptodate bit on
@@ -76,7 +76,7 @@
  * into the cache buffer, which is then marked dirty, and moved onto a
  * third list, the written list (bh_written).  Once both the parity
  * block and the cached buffer are successfully written, any buffer on
- * a written list can be returned with b_end_io.
+ * a written list can be returned with end_io.
  *
  * The write list and read list both act as fifos.  The read list,
  * write list and written list are protected by the device_lock.