[PATCH 3/6] iomap: report file I/O errors to the VFS

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Wire up iomap so that it reports all file read and write errors to the
VFS (and hence fsnotify) via the new fserror mechanism.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/iomap/buffered-io.c |   23 ++++++++++++++++++++++-
 fs/iomap/direct-io.c   |   12 ++++++++++++
 fs/iomap/ioend.c       |    6 ++++++
 3 files changed, 40 insertions(+), 1 deletion(-)


diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index e5c1ca440d93bd..b21e989b9fa5e6 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -8,6 +8,7 @@
 #include <linux/writeback.h>
 #include <linux/swap.h>
 #include <linux/migrate.h>
+#include <linux/fserror.h>
 #include "internal.h"
 #include "trace.h"
 
@@ -371,8 +372,11 @@ static int iomap_read_inline_data(const struct iomap_iter *iter,
 	if (folio_test_uptodate(folio))
 		return 0;
 
-	if (WARN_ON_ONCE(size > iomap->length))
+	if (WARN_ON_ONCE(size > iomap->length)) {
+		fserror_report_io(iter->inode, FSERR_BUFFERED_READ,
+				  iomap->offset, size, -EIO, GFP_NOFS);
 		return -EIO;
+	}
 	if (offset > 0)
 		ifs_alloc(iter->inode, folio, iter->flags);
 
@@ -399,6 +403,11 @@ void iomap_finish_folio_read(struct folio *folio, size_t off, size_t len,
 		spin_unlock_irqrestore(&ifs->state_lock, flags);
 	}
 
+	if (error)
+		fserror_report_io(folio->mapping->host, FSERR_BUFFERED_READ,
+				  folio_pos(folio) + off, len, error,
+				  GFP_ATOMIC);
+
 	if (finished)
 		folio_end_read(folio, uptodate);
 }
@@ -540,6 +549,10 @@ static int iomap_read_folio_iter(struct iomap_iter *iter,
 			if (!*bytes_submitted)
 				iomap_read_init(folio);
 			ret = ctx->ops->read_folio_range(iter, ctx, plen);
+			if (ret < 0)
+				fserror_report_io(iter->inode,
+						  FSERR_BUFFERED_READ, pos,
+						  plen, ret, GFP_NOFS);
 			if (ret)
 				return ret;
 			*bytes_submitted += plen;
@@ -815,6 +828,10 @@ static int __iomap_write_begin(const struct iomap_iter *iter,
 			else
 				status = iomap_bio_read_folio_range_sync(iter,
 						folio, block_start, plen);
+			if (status < 0)
+				fserror_report_io(iter->inode,
+						  FSERR_BUFFERED_READ, pos,
+						  len, status, GFP_NOFS);
 			if (status)
 				return status;
 		}
@@ -1805,6 +1822,7 @@ int iomap_writeback_folio(struct iomap_writepage_ctx *wpc, struct folio *folio)
 	u64 pos = folio_pos(folio);
 	u64 end_pos = pos + folio_size(folio);
 	u64 end_aligned = 0;
+	loff_t orig_pos = pos;
 	size_t bytes_submitted = 0;
 	int error = 0;
 	u32 rlen;
@@ -1848,6 +1866,9 @@ int iomap_writeback_folio(struct iomap_writepage_ctx *wpc, struct folio *folio)
 
 	if (bytes_submitted)
 		wpc->nr_folios++;
+	if (error && pos > orig_pos)
+		fserror_report_io(inode, FSERR_BUFFERED_WRITE, orig_pos, 0,
+				  error, GFP_NOFS);
 
 	/*
 	 * We can have dirty bits set past end of file in page_mkwrite path
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 8e273408453a9c..a06c73eaa8901b 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -7,6 +7,7 @@
 #include <linux/pagemap.h>
 #include <linux/iomap.h>
 #include <linux/task_io_accounting_ops.h>
+#include <linux/fserror.h>
 #include "internal.h"
 #include "trace.h"
 
@@ -78,6 +79,13 @@ static void iomap_dio_submit_bio(const struct iomap_iter *iter,
 	}
 }
 
+static inline enum fserror_type iomap_dio_err_type(const struct iomap_dio *dio)
+{
+	if (dio->flags & IOMAP_DIO_WRITE)
+		return FSERR_DIRECTIO_WRITE;
+	return FSERR_DIRECTIO_READ;
+}
+
 ssize_t iomap_dio_complete(struct iomap_dio *dio)
 {
 	const struct iomap_dio_ops *dops = dio->dops;
@@ -87,6 +95,10 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio)
 
 	if (dops && dops->end_io)
 		ret = dops->end_io(iocb, dio->size, ret, dio->flags);
+	if (dio->error)
+		fserror_report_io(file_inode(iocb->ki_filp),
+				  iomap_dio_err_type(dio), offset, dio->size,
+				  dio->error, GFP_NOFS);
 
 	if (likely(!ret)) {
 		ret = dio->size;
diff --git a/fs/iomap/ioend.c b/fs/iomap/ioend.c
index 86f44922ed3b6a..5b27ee98896707 100644
--- a/fs/iomap/ioend.c
+++ b/fs/iomap/ioend.c
@@ -6,6 +6,7 @@
 #include <linux/list_sort.h>
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
+#include <linux/fserror.h>
 #include "internal.h"
 #include "trace.h"
 
@@ -55,6 +56,11 @@ static 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)
+			fserror_report_io(inode, FSERR_BUFFERED_WRITE,
+					  folio_pos(fi.folio) + fi.offset,
+					  fi.length, ioend->io_error,
+					  GFP_ATOMIC);
 		iomap_finish_folio_write(inode, fi.folio, fi.length);
 		folio_count++;
 	}