[05/16] iomap, filemap: report buffered read and write io errors to the filesystem

Commit Message

Darrick J. Wong Dec. 31, 2024, 11:40 p.m. UTC

From: Darrick J. Wong <[e-mail]>

Provide a callback so that iomap can report read and write IO errors to
the caller filesystem.  For now this is only wired up for iomap as a
testbed for XFS.

Signed-off-by: "Darrick J. Wong" <[e-mail]>
---
 Documentation/filesystems/vfs.rst |    7 +++++++
 fs/iomap/buffered-io.c            |   26 +++++++++++++++++++++++++-
 include/linux/fs.h                |    4 ++++
 3 files changed, 36 insertions(+), 1 deletion(-)

Patch

diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index 0b18af3f954eb7..2f0ef4e1a8d340 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -827,6 +827,8 @@  cache in your filesystem.  The following members are defined:
 		int (*swap_activate)(struct swap_info_struct *sis, struct file *f, sector_t *span)
 		int (*swap_deactivate)(struct file *);
 		int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
+		void (*ioerror)(struct address_space *mapping, int direction,
+				loff_t pos, u64 len, int error);
 	};
 
 ``writepage``
@@ -1056,6 +1058,11 @@  cache in your filesystem.  The following members are defined:
 ``swap_rw``
 	Called to read or write swap pages when SWP_FS_OPS is set.
 
+``ioerror``
+        Called to deal with IO errors during readahead or writeback.
+        This may be called from interrupt context, and without any
+        locks necessarily being held.
+
 The File Object
 ===============
 
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 86e30b56e8d41b..39782376895306 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -284,6 +284,14 @@  static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
 	*lenp = plen;
 }
 
+static inline void iomap_mapping_ioerror(struct address_space *mapping,
+		int direction, loff_t pos, u64 len, int error)
+{
+	if (mapping && mapping->a_ops->ioerror)
+		mapping->a_ops->ioerror(mapping, direction, pos, len,
+				error);
+}
+
 static void iomap_finish_folio_read(struct folio *folio, size_t off,
 		size_t len, int error)
 {
@@ -302,6 +310,10 @@  static void iomap_finish_folio_read(struct folio *folio, size_t off,
 		spin_unlock_irqrestore(&ifs->state_lock, flags);
 	}
 
+	if (error)
+		iomap_mapping_ioerror(folio->mapping, READ,
+				folio_pos(folio) + off, len, error);
+
 	if (finished)
 		folio_end_read(folio, uptodate);
 }
@@ -670,11 +682,16 @@  static int iomap_read_folio_sync(loff_t block_start, struct folio *folio,
 {
 	struct bio_vec bvec;
 	struct bio bio;
+	int ret;
 
 	bio_init(&bio, iomap->bdev, &bvec, 1, REQ_OP_READ);
 	bio.bi_iter.bi_sector = iomap_sector(iomap, block_start);
 	bio_add_folio_nofail(&bio, folio, plen, poff);
-	return submit_bio_wait(&bio);
+	ret = submit_bio_wait(&bio);
+	if (ret)
+		iomap_mapping_ioerror(folio->mapping, READ,
+				folio_pos(folio) + poff, plen, ret);
+	return ret;
 }
 
 static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
@@ -1573,6 +1590,11 @@  u32 iomap_finish_ioend_buffered(struct iomap_ioend *ioend)
 
 	/* walk all folios in bio, ending page IO on them */
 	bio_for_each_folio_all(fi, bio) {
+		if (ioend->io_error)
+			iomap_mapping_ioerror(inode->i_mapping, WRITE,
+					folio_pos(fi.folio) + fi.offset,
+					fi.length, ioend->io_error);
+
 		iomap_finish_folio_write(inode, fi.folio, fi.length);
 		folio_count++;
 	}
@@ -1881,6 +1903,8 @@  static int iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 
 	if (count)
 		wpc->nr_folios++;
+	if (error && !count)
+		iomap_mapping_ioerror(inode->i_mapping, WRITE, pos, 0, error);
 
 	/*
 	 * We can have dirty bits set past end of file in page_mkwrite path
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b638fb1bcbc96f..9375753577025d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -438,6 +438,10 @@  struct address_space_operations {
 				sector_t *span);
 	void (*swap_deactivate)(struct file *file);
 	int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
+
+	/* Callback for dealing with IO errors during readahead or writeback */
+	void (*ioerror)(struct address_space *mapping, int direction,
+			loff_t pos, u64 len, int error);
 };
 
 extern const struct address_space_operations empty_aops;