[PATCH 08/13] fs: Teach callers of kiocb_start_write() to handle errors

[Jan Kara <jack@xxxxxxx>]

sb_start_write() will be returning error on shutdown filesystem. Teach
callers of kiocb_start_write() to handle the error.

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 fs/aio.c           | 14 +++++++++-----
 fs/read_write.c    |  4 +++-
 include/linux/fs.h |  3 ++-
 io_uring/rw.c      |  7 +++++--
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 48d99221ff57..3b94081118bc 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1626,12 +1626,16 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
 	if (ret < 0)
 		return ret;
 	ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
-	if (!ret) {
-		if (S_ISREG(file_inode(file)->i_mode))
-			kiocb_start_write(req);
-		req->ki_flags |= IOCB_WRITE;
-		aio_rw_done(req, file->f_op->write_iter(req, &iter));
+	if (unlikely(ret))
+		goto out;
+	if (S_ISREG(file_inode(file)->i_mode)) {
+		ret = kiocb_start_write(req);
+		if (unlikely(ret))
+			goto out;
 	}
+	req->ki_flags |= IOCB_WRITE;
+	aio_rw_done(req, file->f_op->write_iter(req, &iter));
+out:
 	kfree(iovec);
 	return ret;
 }
diff --git a/fs/read_write.c b/fs/read_write.c
index 90e283b31ca1..12996892bb1d 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -859,7 +859,9 @@ ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
 	if (ret < 0)
 		return ret;
 
-	kiocb_start_write(iocb);
+	ret = kiocb_start_write(iocb);
+	if (ret < 0)
+		return ret;
 	ret = file->f_op->write_iter(iocb, iter);
 	if (ret != -EIOCBQUEUED)
 		kiocb_end_write(iocb);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 52841aab13fb..3ac37d9884f5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2920,7 +2920,7 @@ static inline void file_end_write(struct file *file)
  * This is a variant of sb_start_write() for async io submission.
  * Should be matched with a call to kiocb_end_write().
  */
-static inline void kiocb_start_write(struct kiocb *iocb)
+static inline int __must_check kiocb_start_write(struct kiocb *iocb)
 {
 	struct inode *inode = file_inode(iocb->ki_filp);
 
@@ -2930,6 +2930,7 @@ static inline void kiocb_start_write(struct kiocb *iocb)
 	 * doesn't complain about the held lock when we return to userspace.
 	 */
 	__sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
+	return 0;
 }
 
 /**
diff --git a/io_uring/rw.c b/io_uring/rw.c
index c004d21e2f12..a9dc9f84fb60 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -1040,8 +1040,11 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
 	if (unlikely(ret))
 		return ret;
 
-	if (req->flags & REQ_F_ISREG)
-		kiocb_start_write(kiocb);
+	if (req->flags & REQ_F_ISREG) {
+		ret = kiocb_start_write(kiocb);
+		if (unlikely(ret))
+			return ret;
+	}
 	kiocb->ki_flags |= IOCB_WRITE;
 
 	if (likely(req->file->f_op->write_iter))
-- 
2.35.3