Merge patch series "iomap: buffered io changes"

This series contains several fixes and cleanups:

* Renaming bytes_pending/bytes_accounted to
  bytes_submitted/bytes_not_submitted for improved code clarity

* Accounting for unaligned end offsets when truncating read ranges

* Adding documentation for iomap_finish_folio_write() requirements

* Optimizing pending async writeback accounting logic

* Simplifying error handling in ->read_folio_range() for read operations

* Streamlining logic for skipping reads during write operations

* Replacing manual bitmap scanning with find_next_bit() for both dirty
  and uptodate bitmaps, improving performance

* patches from https://patch.msgid.link/20251111193658.3495942-1-joannelkoong@gmail.com:
  iomap: use find_next_bit() for uptodate bitmap scanning
  iomap: use find_next_bit() for dirty bitmap scanning
  iomap: simplify when reads can be skipped for writes
  iomap: simplify ->read_folio_range() error handling for reads
  iomap: optimize pending async writeback accounting
  docs: document iomap writeback's iomap_finish_folio_write() requirement
  iomap: account for unaligned end offsets when truncating read range
  iomap: rename bytes_pending/bytes_accounted to bytes_submitted/bytes_not_submitted

Link: https://patch.msgid.link/20251111193658.3495942-1-joannelkoong@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 8b1ac08c7474..520e967cb501 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -435,6 +435,10 @@ struct iomap_writeback_ops {
 	 * An existing mapping from a previous call to this method can be reused
 	 * by the file system if it is still valid.
 	 *
+	 * If this succeeds, iomap_finish_folio_write() must be called once
+	 * writeback completes for the range, regardless of whether the
+	 * writeback succeeded or failed.
+	 *
 	 * Returns the number of bytes processed or a negative errno.
 	 */
 	ssize_t (*writeback_range)(struct iomap_writepage_ctx *wpc,
@@ -474,8 +478,6 @@ int iomap_ioend_writeback_submit(struct iomap_writepage_ctx *wpc, int error);
 
 void iomap_finish_folio_read(struct folio *folio, size_t off, size_t len,
 		int error);
-void iomap_start_folio_write(struct inode *inode, struct folio *folio,
-		size_t len);
 void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
 		size_t len);
 
@@ -493,9 +495,8 @@ struct iomap_read_ops {
 	/*
 	 * Read in a folio range.
 	 *
-	 * The caller is responsible for calling iomap_finish_folio_read() after
-	 * reading in the folio range. This should be done even if an error is
-	 * encountered during the read.
+	 * If this succeeds, iomap_finish_folio_read() must be called after the
+	 * range is read in, regardless of whether the read succeeded or failed.
 	 *
 	 * Returns 0 on success or a negative error on failure.
 	 */