[PATCH 06/10] keep iocb_flags() result cached in struct file

From: Al Viro <viro@zeniv.linux.org.uk>
To: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
	Matthew Wilcox <willy@infradead.org>
Subject: [PATCH 06/10] keep iocb_flags() result cached in struct file
Date: Tue,  7 Jun 2022 23:31:39 +0000	[thread overview]
Message-ID: <20220607233143.1168114-6-viro@zeniv.linux.org.uk> (raw)
In-Reply-To: <20220607233143.1168114-1-viro@zeniv.linux.org.uk>

* calculate at the time we set FMODE_OPENED (do_dentry_open() for normal
opens, alloc_file() for pipe()/socket()/etc.)
* update when handling F_SETFL
* keep in a new field - file->f_i_flags; since that thing is needed only
before the refcount reaches zero, we can put it into the same anon union
where ->f_rcuhead and ->f_llist live - those are used only after refcount
reaches zero.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 drivers/nvme/target/io-cmd-file.c | 2 +-
 fs/aio.c                          | 2 +-
 fs/fcntl.c                        | 1 +
 fs/file_table.c                   | 1 +
 fs/io_uring.c                     | 2 +-
 fs/open.c                         | 1 +
 include/linux/fs.h                | 5 ++---
 7 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index f3d58abf11e0..2be306fe9c13 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -112,7 +112,7 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
 
 	iocb->ki_pos = pos;
 	iocb->ki_filp = req->ns->file;
-	iocb->ki_flags = ki_flags | iocb_flags(req->ns->file);
+	iocb->ki_flags = ki_flags | iocb->ki_filp->f_i_flags;
 
 	return call_iter(iocb, &iter);
 }
diff --git a/fs/aio.c b/fs/aio.c
index 3c249b938632..fb84adb6dc00 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1475,7 +1475,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 	req->ki_complete = aio_complete_rw;
 	req->private = NULL;
 	req->ki_pos = iocb->aio_offset;
-	req->ki_flags = iocb_flags(req->ki_filp);
+	req->ki_flags = req->ki_filp->f_i_flags;
 	if (iocb->aio_flags & IOCB_FLAG_RESFD)
 		req->ki_flags |= IOCB_EVENTFD;
 	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 34a3faa4886d..696faccb1726 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -78,6 +78,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 	}
 	spin_lock(&filp->f_lock);
 	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
+	filp->f_i_flags = iocb_flags(filp);
 	spin_unlock(&filp->f_lock);
 
  out:
diff --git a/fs/file_table.c b/fs/file_table.c
index b989e33aacda..3d1800ad3857 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -241,6 +241,7 @@ static struct file *alloc_file(const struct path *path, int flags,
 	if ((file->f_mode & FMODE_WRITE) &&
 	     likely(fop->write || fop->write_iter))
 		file->f_mode |= FMODE_CAN_WRITE;
+	file->f_i_flags = iocb_flags(file);
 	file->f_mode |= FMODE_OPENED;
 	file->f_op = fop;
 	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3aab4182fd89..79d475bebf30 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4330,7 +4330,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
 	if (!io_req_ffs_set(req))
 		req->flags |= io_file_get_flags(file) << REQ_F_SUPPORT_NOWAIT_BIT;
 
-	kiocb->ki_flags = iocb_flags(file);
+	kiocb->ki_flags = file->f_i_flags;
 	ret = kiocb_set_rw_flags(kiocb, req->rw.flags);
 	if (unlikely(ret))
 		return ret;
diff --git a/fs/open.c b/fs/open.c
index 1d57fbde2feb..1f45c63716ee 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -862,6 +862,7 @@ static int do_dentry_open(struct file *f,
 		f->f_mode |= FMODE_CAN_ODIRECT;
 
 	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
+	f->f_i_flags = iocb_flags(f);
 
 	file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 380a1292f4f9..7f4530a219b6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -926,6 +926,7 @@ struct file {
 	union {
 		struct llist_node	f_llist;
 		struct rcu_head 	f_rcuhead;
+		unsigned int 		f_i_flags;
 	};
 	struct path		f_path;
 	struct inode		*f_inode;	/* cached value */
@@ -2199,13 +2200,11 @@ static inline bool HAS_UNMAPPED_ID(struct user_namespace *mnt_userns,
 	       !gid_valid(i_gid_into_mnt(mnt_userns, inode));
 }
 
-static inline int iocb_flags(struct file *file);
-
 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
 {
 	*kiocb = (struct kiocb) {
 		.ki_filp = filp,
-		.ki_flags = iocb_flags(filp),
+		.ki_flags = filp->f_i_flags,
 		.ki_ioprio = get_current_ioprio(),
 	};
 }
-- 
2.30.2

