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Commit 36cf66ed authored by Maxim Patlasov's avatar Maxim Patlasov Committed by Miklos Szeredi
Browse files

fuse: make fuse_direct_io() aware about AIO 



The patch implements passing "struct fuse_io_priv *io" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
io->async==0 designates synchronous processing.

Non-trivial part of the patch is changes in fuse_direct_io(): resources
like fuse requests and user pages cannot be released immediately in async
case.

Signed-off-by: default avatarMaxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent 01e9d11a

fs/fuse/cuse.c

+4 −2
Original line number Diff line number Diff line
@@ -92,8 +92,9 @@ static ssize_t cuse_read(struct file *file, char __user *buf, size_t count, 
{

	loff_t pos = 0;

	struct iovec iov = { .iov_base = buf, .iov_len = count };

	struct fuse_io_priv io = { .async = 0, .file = file };



	return fuse_direct_io(file, &iov, 1, count, &pos, 0);

	return fuse_direct_io(&io, &iov, 1, count, &pos, 0);

}



static ssize_t cuse_write(struct file *file, const char __user *buf,
@@ -101,12 +102,13 @@ static ssize_t cuse_write(struct file *file, const char __user *buf, 
{

	loff_t pos = 0;

	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };

	struct fuse_io_priv io = { .async = 0, .file = file };



	/*

	 * No locking or generic_write_checks(), the server is

	 * responsible for locking and sanity checks.

	 */

	return fuse_direct_io(file, &iov, 1, count, &pos, 1);

	return fuse_direct_io(&io, &iov, 1, count, &pos, 1);

}



static int cuse_open(struct inode *inode, struct file *file)

fs/fuse/dev.c

+1 −1
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ static void restore_sigs(sigset_t *oldset) 
	sigprocmask(SIG_SETMASK, oldset, NULL);

}



static void __fuse_get_request(struct fuse_req *req)

void __fuse_get_request(struct fuse_req *req)

{

	atomic_inc(&req->count);

}

fs/fuse/file.c

+47 −17
Original line number Diff line number Diff line
@@ -593,14 +593,16 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req, 
	req->io = io;

	req->end = fuse_aio_complete_req;



	__fuse_get_request(req);

	fuse_request_send_background(fc, req);



	return num_bytes;

}



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

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 fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;
@@ -611,6 +613,10 @@ static size_t fuse_send_read(struct fuse_req *req, struct file *file, 
		inarg->read_flags |= FUSE_READ_LOCKOWNER;

		inarg->lock_owner = fuse_lock_owner_id(fc, owner);

	}



	if (io->async)

		return fuse_async_req_send(fc, req, count, io);



	fuse_request_send(fc, req);

	return req->out.args[0].size;

}
@@ -631,6 +637,7 @@ static void fuse_read_update_size(struct inode *inode, loff_t size, 


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

{

	struct fuse_io_priv io = { .async = 0, .file = file };

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

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_req *req;
@@ -663,7 +670,7 @@ static int fuse_readpage(struct file *file, struct page *page) 
	req->num_pages = 1;

	req->pages[0] = page;

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

	num_read = fuse_send_read(req, file, pos, count, NULL);

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

	err = req->out.h.error;

	fuse_put_request(fc, req);
@@ -873,9 +880,10 @@ static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff, 
	req->out.args[0].value = outarg;

}



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

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 fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;

	struct fuse_write_in *inarg = &req->misc.write.in;
@@ -886,6 +894,10 @@ static size_t fuse_send_write(struct fuse_req *req, struct file *file, 
		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;

		inarg->lock_owner = fuse_lock_owner_id(fc, owner);

	}



	if (io->async)

		return fuse_async_req_send(fc, req, count, io);



	fuse_request_send(fc, req);

	return req->misc.write.out.size;

}
@@ -909,11 +921,12 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, 
	size_t res;

	unsigned offset;

	unsigned i;

	struct fuse_io_priv io = { .async = 0, .file = file };



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

		fuse_wait_on_page_writeback(inode, req->pages[i]->index);



	res = fuse_send_write(req, file, pos, count, NULL);

	res = fuse_send_write(req, &io, pos, count, NULL);



	offset = req->page_descs[0].offset;

	count = res;
@@ -1251,10 +1264,11 @@ static inline int fuse_iter_npages(const struct iov_iter *ii_p) 
	return min(npages, FUSE_MAX_PAGES_PER_REQ);

}



ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,

ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,

		       unsigned long nr_segs, size_t count, loff_t *ppos,

		       int write)

{

	struct file *file = io->file;

	struct fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fc;

	size_t nmax = write ? fc->max_write : fc->max_read;
@@ -1280,10 +1294,11 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov, 
		}



		if (write)

			nres = fuse_send_write(req, file, pos, nbytes, owner);

			nres = fuse_send_write(req, io, pos, nbytes, owner);

		else

			nres = fuse_send_read(req, file, pos, nbytes, owner);

			nres = fuse_send_read(req, io, pos, nbytes, owner);



		if (!io->async)

			fuse_release_user_pages(req, !write);

		if (req->out.h.error) {

			if (!res)
@@ -1314,16 +1329,18 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov, 
}

EXPORT_SYMBOL_GPL(fuse_direct_io);



static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov,

static ssize_t __fuse_direct_read(struct fuse_io_priv *io,

				  const struct iovec *iov,

				  unsigned long nr_segs, loff_t *ppos)

{

	ssize_t res;

	struct file *file = io->file;

	struct inode *inode = file_inode(file);



	if (is_bad_inode(inode))

		return -EIO;



	res = fuse_direct_io(file, iov, nr_segs, iov_length(iov, nr_segs),

	res = fuse_direct_io(io, iov, nr_segs, iov_length(iov, nr_segs),

			     ppos, 0);



	fuse_invalidate_attr(inode);
@@ -1334,21 +1351,24 @@ static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov, 
static ssize_t fuse_direct_read(struct file *file, char __user *buf,

				     size_t count, loff_t *ppos)

{

	struct fuse_io_priv io = { .async = 0, .file = file };

	struct iovec iov = { .iov_base = buf, .iov_len = count };

	return __fuse_direct_read(file, &iov, 1, ppos);

	return __fuse_direct_read(&io, &iov, 1, ppos);

}



static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov,

static ssize_t __fuse_direct_write(struct fuse_io_priv *io,

				   const struct iovec *iov,

				   unsigned long nr_segs, loff_t *ppos)

{

	struct file *file = io->file;

	struct inode *inode = file_inode(file);

	size_t count = iov_length(iov, nr_segs);

	ssize_t res;



	res = generic_write_checks(file, ppos, &count, 0);

	if (!res) {

		res = fuse_direct_io(file, iov, nr_segs, count, ppos, 1);

		if (res > 0)

		res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1);

		if (!io->async && res > 0)

			fuse_write_update_size(inode, *ppos);

	}
@@ -1363,13 +1383,14 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf, 
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };

	struct inode *inode = file_inode(file);

	ssize_t res;

	struct fuse_io_priv io = { .async = 0, .file = file };



	if (is_bad_inode(inode))

		return -EIO;



	/* Don't allow parallel writes to the same file */

	mutex_lock(&inode->i_mutex);

	res = __fuse_direct_write(file, &iov, 1, ppos);

	res = __fuse_direct_write(&io, &iov, 1, ppos);

	mutex_unlock(&inode->i_mutex);



	return res;
@@ -2339,14 +2360,23 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, 
	ssize_t ret = 0;

	struct file *file = NULL;

	loff_t pos = 0;

	struct fuse_io_priv *io;



	file = iocb->ki_filp;

	pos = offset;



	io = kzalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);

	if (!io)

		return -ENOMEM;



	io->file = file;



	if (rw == WRITE)

		ret = __fuse_direct_write(file, iov, nr_segs, &pos);

		ret = __fuse_direct_write(io, iov, nr_segs, &pos);

	else

		ret = __fuse_direct_read(file, iov, nr_segs, &pos);

		ret = __fuse_direct_read(io, iov, nr_segs, &pos);



	kfree(io);



	return ret;

}

fs/fuse/fuse_i.h

+6 −1
Original line number Diff line number Diff line
@@ -732,6 +732,11 @@ struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages); 
struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,

					     unsigned npages);



/*

 * Increment reference count on request

 */

void __fuse_get_request(struct fuse_req *req);



/**

 * Get a request, may fail with -ENOMEM,

 * useful for callers who doesn't use req->pages[]
@@ -846,7 +851,7 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, 


int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,

		 bool isdir);

ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,

ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,

		       unsigned long nr_segs, size_t count, loff_t *ppos,

		       int write);

long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,