Commit ed22e1db authored by David Howells's avatar David Howells
Browse files

netfs, afs: Implement helpers for new write code 



Implement the helpers for the new write code in afs.  There's now an
optional ->prepare_write() that allows the filesystem to set the parameters
for the next write, such as maximum size and maximum segment count, and an
->issue_write() that is called to initiate an (asynchronous) write
operation.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
parent 4824e591

fs/afs/file.c

+3 −0
Original line number Diff line number Diff line
@@ -400,6 +400,9 @@ const struct netfs_request_ops afs_req_ops = { 
	.update_i_size		= afs_update_i_size,

	.invalidate_cache	= afs_netfs_invalidate_cache,

	.create_write_requests	= afs_create_write_requests,

	.begin_writeback	= afs_begin_writeback,

	.prepare_write		= afs_prepare_write,

	.issue_write		= afs_issue_write,

};



static void afs_add_open_mmap(struct afs_vnode *vnode)

fs/afs/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -1598,6 +1598,9 @@ extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *); 
/*

 * write.c

 */

void afs_prepare_write(struct netfs_io_subrequest *subreq);

void afs_issue_write(struct netfs_io_subrequest *subreq);

void afs_begin_writeback(struct netfs_io_request *wreq);

extern int afs_writepages(struct address_space *, struct writeback_control *);

extern int afs_fsync(struct file *, loff_t, loff_t, int);

extern vm_fault_t afs_page_mkwrite(struct vm_fault *vmf);

fs/afs/write.c

+54 −0
Original line number Diff line number Diff line
@@ -194,6 +194,60 @@ void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size 
		netfs_queue_write_request(subreq);

}



/*

 * Writeback calls this when it finds a folio that needs uploading.  This isn't

 * called if writeback only has copy-to-cache to deal with.

 */

void afs_begin_writeback(struct netfs_io_request *wreq)

{

	wreq->io_streams[0].avail = true;

}



/*

 * Prepare a subrequest to write to the server.  This sets the max_len

 * parameter.

 */

void afs_prepare_write(struct netfs_io_subrequest *subreq)

{

	//if (test_bit(NETFS_SREQ_RETRYING, &subreq->flags))

	//	subreq->max_len = 512 * 1024;

	//else

	subreq->max_len = 256 * 1024 * 1024;

}



/*

 * Issue a subrequest to write to the server.

 */

static void afs_issue_write_worker(struct work_struct *work)

{

	struct netfs_io_subrequest *subreq = container_of(work, struct netfs_io_subrequest, work);

	struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);

	ssize_t ret;



	_enter("%x[%x],%zx",

	       subreq->rreq->debug_id, subreq->debug_index, subreq->io_iter.count);



#if 0 // Error injection

	if (subreq->debug_index == 3)

		return netfs_write_subrequest_terminated(subreq, -ENOANO, false);



	if (!test_bit(NETFS_SREQ_RETRYING, &subreq->flags)) {

		set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags);

		return netfs_write_subrequest_terminated(subreq, -EAGAIN, false);

	}

#endif



	ret = afs_store_data(vnode, &subreq->io_iter, subreq->start);

	netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len, false);

}



void afs_issue_write(struct netfs_io_subrequest *subreq)

{

	subreq->work.func = afs_issue_write_worker;

	if (!queue_work(system_unbound_wq, &subreq->work))

		WARN_ON_ONCE(1);

}



/*

 * write some of the pending data back to the server

 */