Commit 2de16041 authored by David Howells's avatar David Howells
Browse files

netfs: Change ->init_request() to return an error code 



Change the request initialisation function to return an error code so that
the network filesystem can return a failure (ENOMEM, for example).

This will also allow ceph to abort a ->readahead() op if the server refuses
to give it a cap allowing local caching from within the netfslib framework
(errors aren't passed back through ->readahead(), so returning, say,
-ENOBUFS will cause the op to be aborted).

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com

Link: https://lore.kernel.org/r/164678212401.1200972.16537041523832944934.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692905398.2099075.5238033621684646524.stgit@warthog.procyon.org.uk/ # v3
parent 663dfb65

fs/9p/vfs_addr.c

+2 −1
Original line number Diff line number Diff line
@@ -56,12 +56,13 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq) 
 * @rreq: The read request

 * @file: The file being read from

 */

static void v9fs_init_request(struct netfs_io_request *rreq, struct file *file)

static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)

{

	struct p9_fid *fid = file->private_data;



	refcount_inc(&fid->count);

	rreq->netfs_priv = fid;

	return 0;

}



/**

fs/afs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -359,9 +359,10 @@ static int afs_symlink_readpage(struct file *file, struct page *page) 
	return ret;

}



static void afs_init_request(struct netfs_io_request *rreq, struct file *file)

static int afs_init_request(struct netfs_io_request *rreq, struct file *file)

{

	rreq->netfs_priv = key_get(afs_file_key(file));

	return 0;

}



static bool afs_is_cache_enabled(struct inode *inode)

fs/netfs/objects.c

+24 −17
Original line number Diff line number Diff line
@@ -20,9 +20,12 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 
{

	static atomic_t debug_ids;

	struct netfs_io_request *rreq;

	int ret;



	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);

	if (rreq) {

	if (!rreq)

		return ERR_PTR(-ENOMEM);



	rreq->start	= start;

	rreq->len	= len;

	rreq->origin	= origin;
@@ -36,11 +39,15 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 
	INIT_WORK(&rreq->work, netfs_rreq_work);

	refcount_set(&rreq->ref, 1);

	__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);

		if (ops->init_request)

			ops->init_request(rreq, file);

		netfs_stat(&netfs_n_rh_rreq);

	if (rreq->netfs_ops->init_request) {

		ret = rreq->netfs_ops->init_request(rreq, file);

		if (ret < 0) {

			kfree(rreq);

			return ERR_PTR(ret);

		}

	}



	netfs_stat(&netfs_n_rh_rreq);

	return rreq;

}

fs/netfs/read_helper.c

+12 −8
Original line number Diff line number Diff line
@@ -768,7 +768,7 @@ void netfs_readahead(struct readahead_control *ractl, 
				   readahead_pos(ractl),

				   readahead_length(ractl),

				   NETFS_READAHEAD);

	if (!rreq)

	if (IS_ERR(rreq))

		goto cleanup;



	if (ops->begin_cache_operation) {
@@ -842,11 +842,9 @@ int netfs_readpage(struct file *file, 
	rreq = netfs_alloc_request(folio->mapping, file, ops, netfs_priv,

				   folio_file_pos(folio), folio_size(folio),

				   NETFS_READPAGE);

	if (!rreq) {

		if (netfs_priv)

			ops->cleanup(folio_file_mapping(folio), netfs_priv);

		folio_unlock(folio);

		return -ENOMEM;

	if (IS_ERR(rreq)) {

		ret = PTR_ERR(rreq);

		goto alloc_error;

	}



	if (ops->begin_cache_operation) {
@@ -887,6 +885,11 @@ int netfs_readpage(struct file *file, 
out:

	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);

	return ret;

alloc_error:

	if (netfs_priv)

		ops->cleanup(folio_file_mapping(folio), netfs_priv);

	folio_unlock(folio);

	return ret;

}

EXPORT_SYMBOL(netfs_readpage);
@@ -1007,12 +1010,13 @@ int netfs_write_begin(struct file *file, struct address_space *mapping, 
		goto have_folio_no_wait;

	}



	ret = -ENOMEM;

	rreq = netfs_alloc_request(mapping, file, ops, netfs_priv,

				   folio_file_pos(folio), folio_size(folio),

				   NETFS_READ_FOR_WRITE);

	if (!rreq)

	if (IS_ERR(rreq)) {

		ret = PTR_ERR(rreq);

		goto error;

	}

	rreq->no_unlock_folio	= folio_index(folio);

	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);

	netfs_priv = NULL;

include/linux/netfs.h

+1 −1
Original line number Diff line number Diff line
@@ -193,7 +193,7 @@ struct netfs_io_request { 
 */

struct netfs_request_ops {

	bool (*is_cache_enabled)(struct inode *inode);

	void (*init_request)(struct netfs_io_request *rreq, struct file *file);

	int (*init_request)(struct netfs_io_request *rreq, struct file *file);

	int (*begin_cache_operation)(struct netfs_io_request *rreq);

	void (*expand_readahead)(struct netfs_io_request *rreq);

	bool (*clamp_length)(struct netfs_io_subrequest *subreq);