[PATCH v5 05/17] fs: Restore kiocb.ki_hint

[Bart Van Assche <bvanassche@acm.org>]

Restore support for passing file and/or inode write hints to the code
that processes struct kiocb. This patch reverts commit 41d36a9f3e53
("fs: remove kiocb.ki_hint").

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 fs/aio.c                    | 1 +
 fs/f2fs/file.c              | 6 ++++++
 include/linux/fs.h          | 3 +++
 include/trace/events/f2fs.h | 5 ++++-
 io_uring/rw.c               | 1 +
 5 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/fs/aio.c b/fs/aio.c
index f8589caef9c1..a9dc84a984db 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1466,6 +1466,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 	req->ki_flags = req->ki_filp->f_iocb_flags;
 	if (iocb->aio_flags & IOCB_FLAG_RESFD)
 		req->ki_flags |= IOCB_EVENTFD;
+	req->ki_hint = file_write_hint(req->ki_filp);
 	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
 		/*
 		 * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index e50363583f01..6ffafa29f1a2 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4644,8 +4644,10 @@ static ssize_t f2fs_dio_write_iter(struct kiocb *iocb, struct iov_iter *from,
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	const bool do_opu = f2fs_lfs_mode(sbi);
+	const int whint_mode = F2FS_OPTION(sbi).whint_mode;
 	const loff_t pos = iocb->ki_pos;
 	const ssize_t count = iov_iter_count(from);
+	const enum rw_hint hint = iocb->ki_hint;
 	unsigned int dio_flags;
 	struct iomap_dio *dio;
 	ssize_t ret;
@@ -4678,6 +4680,8 @@ static ssize_t f2fs_dio_write_iter(struct kiocb *iocb, struct iov_iter *from,
 		if (do_opu)
 			f2fs_down_read(&fi->i_gc_rwsem[READ]);
 	}
+	if (whint_mode == WHINT_MODE_OFF)
+		iocb->ki_hint = WRITE_LIFE_NOT_SET;
 
 	/*
 	 * We have to use __iomap_dio_rw() and iomap_dio_complete() instead of
@@ -4700,6 +4704,8 @@ static ssize_t f2fs_dio_write_iter(struct kiocb *iocb, struct iov_iter *from,
 		ret = iomap_dio_complete(dio);
 	}
 
+	if (whint_mode == WHINT_MODE_OFF)
+		iocb->ki_hint = hint;
 	if (do_opu)
 		f2fs_up_read(&fi->i_gc_rwsem[READ]);
 	f2fs_up_read(&fi->i_gc_rwsem[WRITE]);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a6e0c4b5a72b..acc0cbab93dd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -362,6 +362,7 @@ struct kiocb {
 	void (*ki_complete)(struct kiocb *iocb, long ret);
 	void			*private;
 	int			ki_flags;
+	u8			ki_hint;
 	u16			ki_ioprio; /* See linux/ioprio.h */
 	union {
 		/*
@@ -2176,6 +2177,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
 	*kiocb = (struct kiocb) {
 		.ki_filp = filp,
 		.ki_flags = filp->f_iocb_flags,
+		.ki_hint = file_write_hint(filp),
 		.ki_ioprio = get_current_ioprio(),
 	};
 }
@@ -2186,6 +2188,7 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
 	*kiocb = (struct kiocb) {
 		.ki_filp = filp,
 		.ki_flags = kiocb_src->ki_flags,
+		.ki_hint = kiocb_src->ki_hint,
 		.ki_ioprio = kiocb_src->ki_ioprio,
 		.ki_pos = kiocb_src->ki_pos,
 	};
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 793f82cc1515..eb9ba109949e 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -946,6 +946,7 @@ TRACE_EVENT(f2fs_direct_IO_enter,
 		__field(ino_t,	ino)
 		__field(loff_t,	ki_pos)
 		__field(int,	ki_flags)
+		__field(u16,	ki_hint)
 		__field(u16,	ki_ioprio)
 		__field(unsigned long,	len)
 		__field(int,	rw)
@@ -956,16 +957,18 @@ TRACE_EVENT(f2fs_direct_IO_enter,
 		__entry->ino		= inode->i_ino;
 		__entry->ki_pos		= iocb->ki_pos;
 		__entry->ki_flags	= iocb->ki_flags;
+		__entry->ki_hint	= iocb->ki_hint;
 		__entry->ki_ioprio	= iocb->ki_ioprio;
 		__entry->len		= len;
 		__entry->rw		= rw;
 	),
 
-	TP_printk("dev = (%d,%d), ino = %lu pos = %lld len = %lu ki_flags = %x ki_ioprio = %x rw = %d",
+	TP_printk("dev = (%d,%d), ino = %lu pos = %lld len = %lu ki_flags = %x ki_hint = %x ki_ioprio = %x rw = %d",
 		show_dev_ino(__entry),
 		__entry->ki_pos,
 		__entry->len,
 		__entry->ki_flags,
+		__entry->ki_hint,
 		__entry->ki_ioprio,
 		__entry->rw)
 );
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 64390d4e20c1..24a6122c837b 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -994,6 +994,7 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
 		kfree(iovec);
 		return ret;
 	}
+	kiocb->ki_hint = file_write_hint(req->file);
 	req->cqe.res = iov_iter_count(&s->iter);
 
 	if (force_nonblock) {