Merge patch series "filemap_* writeback interface cleanups v2"

Christoph Hellwig <hch@lst.de> says:

While looking at the filemap writeback code, I think adding
filemap_fdatawrite_wbc ended up being a mistake, as all but the original
btrfs caller should be using better high level interfaces instead.  This
series removes all these, switches btrfs to a more specific interfaces
and also cleans up another too low-level interface.  With this the
writeback_control that is passed to the writeback code is only
initialized in three places, although there are a lot more places in
file system code that never reach the common writeback code.

* patches from https://patch.msgid.link/20251024080431.324236-1-hch@lst.de:
  mm: rename filemap_fdatawrite_range_kick to filemap_flush_range
  mm: remove __filemap_fdatawrite_range
  mm: remove filemap_fdatawrite_wbc
  mm: remove __filemap_fdatawrite
  mm,btrfs: add a filemap_flush_nr helper
  btrfs: push struct writeback_control into start_delalloc_inodes
  btrfs: use the local tmp_inode variable in start_delalloc_inodes
  ocfs2: don't opencode filemap_fdatawrite_range in ocfs2_journal_submit_inode_data_buffers
  9p: don't opencode filemap_fdatawrite_range in v9fs_mmap_vm_close
  mm: don't opencode filemap_fdatawrite_range in filemap_invalidate_inode

Link: https://patch.msgid.link/20251024080431.324236-1-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 14 insertions, 32 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3b1b3a0553ee..d12b8116adde 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8709,15 +8709,13 @@ static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode
  * some fairly slow code that needs optimization. This walks the list
  * of all the inodes with pending delalloc and forces them to disk.
  */
-static int start_delalloc_inodes(struct btrfs_root *root,
-				 struct writeback_control *wbc, bool snapshot,
-				 bool in_reclaim_context)
+static int start_delalloc_inodes(struct btrfs_root *root, long *nr_to_write,
+				 bool snapshot, bool in_reclaim_context)
 {
 	struct btrfs_delalloc_work *work, *next;
 	LIST_HEAD(works);
 	LIST_HEAD(splice);
 	int ret = 0;
-	bool full_flush = wbc->nr_to_write == LONG_MAX;
 
 	mutex_lock(&root->delalloc_mutex);
 	spin_lock(&root->delalloc_lock);
@@ -8743,10 +8741,10 @@ static int start_delalloc_inodes(struct btrfs_root *root,
 
 		if (snapshot)
 			set_bit(BTRFS_INODE_SNAPSHOT_FLUSH, &inode->runtime_flags);
-		if (full_flush) {
-			work = btrfs_alloc_delalloc_work(&inode->vfs_inode);
+		if (nr_to_write == NULL) {
+			work = btrfs_alloc_delalloc_work(tmp_inode);
 			if (!work) {
-				iput(&inode->vfs_inode);
+				iput(tmp_inode);
 				ret = -ENOMEM;
 				goto out;
 			}
@@ -8754,9 +8752,11 @@ static int start_delalloc_inodes(struct btrfs_root *root,
 			btrfs_queue_work(root->fs_info->flush_workers,
 					 &work->work);
 		} else {
-			ret = filemap_fdatawrite_wbc(inode->vfs_inode.i_mapping, wbc);
+			ret = filemap_flush_nr(tmp_inode->i_mapping,
+					nr_to_write);
 			btrfs_add_delayed_iput(inode);
-			if (ret || wbc->nr_to_write <= 0)
+
+			if (ret || *nr_to_write <= 0)
 				goto out;
 		}
 		cond_resched();
@@ -8782,29 +8782,17 @@ out:
 
 int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context)
 {
-	struct writeback_control wbc = {
-		.nr_to_write = LONG_MAX,
-		.sync_mode = WB_SYNC_NONE,
-		.range_start = 0,
-		.range_end = LLONG_MAX,
-	};
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	if (BTRFS_FS_ERROR(fs_info))
 		return -EROFS;
-
-	return start_delalloc_inodes(root, &wbc, true, in_reclaim_context);
+	return start_delalloc_inodes(root, NULL, true, in_reclaim_context);
 }
 
 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
 			       bool in_reclaim_context)
 {
-	struct writeback_control wbc = {
-		.nr_to_write = nr,
-		.sync_mode = WB_SYNC_NONE,
-		.range_start = 0,
-		.range_end = LLONG_MAX,
-	};
+	long *nr_to_write = nr == LONG_MAX ? NULL : &nr;
 	struct btrfs_root *root;
 	LIST_HEAD(splice);
 	int ret;
@@ -8816,13 +8804,6 @@ int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
 	spin_lock(&fs_info->delalloc_root_lock);
 	list_splice_init(&fs_info->delalloc_roots, &splice);
 	while (!list_empty(&splice)) {
-		/*
-		 * Reset nr_to_write here so we know that we're doing a full
-		 * flush.
-		 */
-		if (nr == LONG_MAX)
-			wbc.nr_to_write = LONG_MAX;
-
 		root = list_first_entry(&splice, struct btrfs_root,
 					delalloc_root);
 		root = btrfs_grab_root(root);
@@ -8831,9 +8812,10 @@ int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
 			       &fs_info->delalloc_roots);
 		spin_unlock(&fs_info->delalloc_root_lock);
 
-		ret = start_delalloc_inodes(root, &wbc, false, in_reclaim_context);
+		ret = start_delalloc_inodes(root, nr_to_write, false,
+				in_reclaim_context);
 		btrfs_put_root(root);
-		if (ret < 0 || wbc.nr_to_write <= 0)
+		if (ret < 0 || nr <= 0)
 			goto out;
 		spin_lock(&fs_info->delalloc_root_lock);
 	}