Commit e1c0eecb authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: honor iocb sync flags on write 



If the IOCB_DSYNC flag is set a sync is not being performed by
fuse_file_write_iter.

Honor IOCB_DSYNC/IOCB_SYNC by setting O_DYSNC/O_SYNC respectively in the
flags filed of the write request.

We don't need to sync data or metadata, since fuse_perform_write() does
write-through and the filesystem is responsible for updating file times.

Original patch by Vitaly Zolotusky.

Reported-by: default avatarNate Clark <nate@neworld.us>
Cc: Vitaly Zolotusky <vitaly@unitc.com>.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 5d6d3a30

fs/fuse/cuse.c

+2 −2
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ static struct list_head *cuse_conntbl_head(dev_t devt) 


static ssize_t cuse_read_iter(struct kiocb *kiocb, struct iov_iter *to)

{

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb->ki_filp);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb);

	loff_t pos = 0;



	return fuse_direct_io(&io, to, &pos, FUSE_DIO_CUSE);
@@ -98,7 +98,7 @@ static ssize_t cuse_read_iter(struct kiocb *kiocb, struct iov_iter *to) 


static ssize_t cuse_write_iter(struct kiocb *kiocb, struct iov_iter *from)

{

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb->ki_filp);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb);

	loff_t pos = 0;

	/*

	 * No locking or generic_write_checks(), the server is

fs/fuse/file.c

+24 −17
Original line number Diff line number Diff line
@@ -645,7 +645,7 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req, 
static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,

			     loff_t pos, size_t count, fl_owner_t owner)

{

	struct file *file = io->file;

	struct file *file = io->iocb->ki_filp;

	struct fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;
@@ -707,7 +707,8 @@ static void fuse_short_read(struct fuse_req *req, struct inode *inode, 


static int fuse_do_readpage(struct file *file, struct page *page)

{

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);

	struct kiocb iocb;

	struct fuse_io_priv io;

	struct inode *inode = page->mapping->host;

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_req *req;
@@ -735,6 +736,8 @@ static int fuse_do_readpage(struct file *file, struct page *page) 
	req->num_pages = 1;

	req->pages[0] = page;

	req->page_descs[0].length = count;

	init_sync_kiocb(&iocb, file);

	io = (struct fuse_io_priv) FUSE_IO_PRIV_SYNC(&iocb);

	num_read = fuse_send_read(req, &io, pos, count, NULL);

	err = req->out.h.error;
@@ -957,13 +960,18 @@ static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff, 
static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,

			      loff_t pos, size_t count, fl_owner_t owner)

{

	struct file *file = io->file;

	struct kiocb *iocb = io->iocb;

	struct file *file = iocb->ki_filp;

	struct fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;

	struct fuse_write_in *inarg = &req->misc.write.in;



	fuse_write_fill(req, ff, pos, count);

	inarg->flags = file->f_flags;

	if (iocb->ki_flags & IOCB_DSYNC)

		inarg->flags |= O_DSYNC;

	if (iocb->ki_flags & IOCB_SYNC)

		inarg->flags |= O_SYNC;

	if (owner != NULL) {

		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;

		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
@@ -993,14 +1001,14 @@ bool fuse_write_update_size(struct inode *inode, loff_t pos) 
	return ret;

}



static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,

static size_t fuse_send_write_pages(struct fuse_req *req, struct kiocb *iocb,

				    struct inode *inode, loff_t pos,

				    size_t count)

{

	size_t res;

	unsigned offset;

	unsigned i;

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);



	for (i = 0; i < req->num_pages; i++)

		fuse_wait_on_page_writeback(inode, req->pages[i]->index);
@@ -1100,7 +1108,7 @@ static inline unsigned fuse_wr_pages(loff_t pos, size_t len) 
		     FUSE_MAX_PAGES_PER_REQ);

}



static ssize_t fuse_perform_write(struct file *file,

static ssize_t fuse_perform_write(struct kiocb *iocb,

				  struct address_space *mapping,

				  struct iov_iter *ii, loff_t pos)

{
@@ -1133,7 +1141,7 @@ static ssize_t fuse_perform_write(struct file *file, 
		} else {

			size_t num_written;



			num_written = fuse_send_write_pages(req, file, inode,

			num_written = fuse_send_write_pages(req, iocb, inode,

							    pos, count);

			err = req->out.h.error;

			if (!err) {
@@ -1201,7 +1209,7 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 


		pos += written;



		written_buffered = fuse_perform_write(file, mapping, from, pos);

		written_buffered = fuse_perform_write(iocb, mapping, from, pos);

		if (written_buffered < 0) {

			err = written_buffered;

			goto out;
@@ -1220,13 +1228,15 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		written += written_buffered;

		iocb->ki_pos = pos + written_buffered;

	} else {

		written = fuse_perform_write(file, mapping, from, iocb->ki_pos);

		written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);

		if (written >= 0)

			iocb->ki_pos += written;

	}

out:

	current->backing_dev_info = NULL;

	inode_unlock(inode);

	if (written > 0)

		written = generic_write_sync(iocb, written);



	return written ? written : err;

}
@@ -1317,7 +1327,7 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, 
{

	int write = flags & FUSE_DIO_WRITE;

	int cuse = flags & FUSE_DIO_CUSE;

	struct file *file = io->file;

	struct file *file = io->iocb->ki_filp;

	struct inode *inode = file->f_mapping->host;

	struct fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;
@@ -1399,8 +1409,7 @@ static ssize_t __fuse_direct_read(struct fuse_io_priv *io, 
				  loff_t *ppos)

{

	ssize_t res;

	struct file *file = io->file;

	struct inode *inode = file_inode(file);

	struct inode *inode = file_inode(io->iocb->ki_filp);



	if (is_bad_inode(inode))

		return -EIO;
@@ -1414,15 +1423,14 @@ static ssize_t __fuse_direct_read(struct fuse_io_priv *io, 


static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)

{

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb->ki_filp);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);

	return __fuse_direct_read(&io, to, &iocb->ki_pos);

}



static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)

{

	struct file *file = iocb->ki_filp;

	struct inode *inode = file_inode(file);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);

	struct inode *inode = file_inode(iocb->ki_filp);

	struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);

	ssize_t res;



	if (is_bad_inode(inode))
@@ -2871,7 +2879,6 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
	io->offset = offset;

	io->write = (iov_iter_rw(iter) == WRITE);

	io->err = 0;

	io->file = file;

	/*

	 * By default, we want to optimize all I/Os with async request

	 * submission to the client filesystem if supported.

fs/fuse/fuse_i.h

+2 −3
Original line number Diff line number Diff line
@@ -252,16 +252,15 @@ struct fuse_io_priv { 
	bool should_dirty;

	int err;

	struct kiocb *iocb;

	struct file *file;

	struct completion *done;

	bool blocking;

};



#define FUSE_IO_PRIV_SYNC(f) \

#define FUSE_IO_PRIV_SYNC(i) \

{					\

	.refcnt = KREF_INIT(1),		\

	.async = 0,			\

	.file = f,			\

	.iocb = i,			\

}



/**

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