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: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com

David Howells committed 4 years ago

Commit 2de16041 parent 663dfb65 files · +41 −28Browse files

Unified · Split

5 files

fs/9p/vfs_addr.c +2 −1
fs/afs/file.c +2 −1
fs/netfs/objects.c +24 −17
fs/netfs/read_helper.c +12 −8
include/linux/netfs.h +1 −1

fs/9p/vfs_addr.c+2−1

@@ -56,12 +56,13 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq) · 55 unmodified lines
56	56	* @rreq: The read request
57	57	* @file: The file being read from
58	58	*/
59		−static void v9fs_init_request(struct netfs_io_request rreq, struct file file)
	59	+static int v9fs_init_request(struct netfs_io_request rreq, struct file file)
60	60	{
61	61	struct p9_fid *fid = file->private_data;
62	62
63	63	refcount_inc(&fid->count);
64	64	rreq->netfs_priv = fid;
	65	+ return 0;
65	66	}
66	67
67	68	/**

fs/afs/file.c+2−1

@@ -359,9 +359,10 @@ static int afs_symlink_readpage(struct file file, struct page page) · 358 unmodified lines
359	359	return ret;
360	360	}
361	361
362		−static void afs_init_request(struct netfs_io_request rreq, struct file file)
	362	+static int afs_init_request(struct netfs_io_request rreq, struct file file)
363	363	{
364	364	rreq->netfs_priv = key_get(afs_file_key(file));
	365	+ return 0;
365	366	}
366	367
367	368	static bool afs_is_cache_enabled(struct inode *inode)

fs/netfs/objects.c+24−17

@@ -20,27 +20,34 @@ struct netfs_io_request netfs_alloc_request(struct address_space mapping, · 19 unmodified lines
20	20	{
21	21	static atomic_t debug_ids;
22	22	struct netfs_io_request *rreq;
	23	+ int ret;
23	24
24	25	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
25		− if (rreq) {
26		− rreq->start = start;
27		− rreq->len = len;
28		− rreq->origin = origin;
29		− rreq->netfs_ops = ops;
30		− rreq->netfs_priv = netfs_priv;
31		− rreq->mapping = mapping;
32		− rreq->inode = file_inode(file);
33		− rreq->i_size = i_size_read(rreq->inode);
34		− rreq->debug_id = atomic_inc_return(&debug_ids);
35		− INIT_LIST_HEAD(&rreq->subrequests);
36		− INIT_WORK(&rreq->work, netfs_rreq_work);
37		− refcount_set(&rreq->ref, 1);
38		− __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
39		− if (ops->init_request)
40		− ops->init_request(rreq, file);
41		− netfs_stat(&netfs_n_rh_rreq);
	26	+ if (!rreq)
	27	+ return ERR_PTR(-ENOMEM);
	28	+
	29	+ rreq->start = start;
	30	+ rreq->len = len;
	31	+ rreq->origin = origin;
	32	+ rreq->netfs_ops = ops;
	33	+ rreq->netfs_priv = netfs_priv;
	34	+ rreq->mapping = mapping;
	35	+ rreq->inode = file_inode(file);
	36	+ rreq->i_size = i_size_read(rreq->inode);
	37	+ rreq->debug_id = atomic_inc_return(&debug_ids);
	38	+ INIT_LIST_HEAD(&rreq->subrequests);
	39	+ INIT_WORK(&rreq->work, netfs_rreq_work);
	40	+ refcount_set(&rreq->ref, 1);
	41	+ __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
	42	+ if (rreq->netfs_ops->init_request) {
	43	+ ret = rreq->netfs_ops->init_request(rreq, file);
	44	+ if (ret < 0) {
	45	+ kfree(rreq);
	46	+ return ERR_PTR(ret);
	47	+ }
42	48	}
43	49
	50	+ netfs_stat(&netfs_n_rh_rreq);
44	51	return rreq;
45	52	}
46	53

fs/netfs/read_helper.c+12−8

@@ -768,7 +768,7 @@ void netfs_readahead(struct readahead_control *ractl, · 767 unmodified lines
768	768	readahead_pos(ractl),
769	769	readahead_length(ractl),
770	770	NETFS_READAHEAD);
771		− if (!rreq)
	771	+ if (IS_ERR(rreq))
772	772	goto cleanup;
773	773
774	774	if (ops->begin_cache_operation) {
@@ -842,11 +842,9 @@ int netfs_readpage(struct file *file, · 67 unmodified lines
842	842	rreq = netfs_alloc_request(folio->mapping, file, ops, netfs_priv,
843	843	folio_file_pos(folio), folio_size(folio),
844	844	NETFS_READPAGE);
845		− if (!rreq) {
846		− if (netfs_priv)
847		− ops->cleanup(folio_file_mapping(folio), netfs_priv);
848		− folio_unlock(folio);
849		− return -ENOMEM;
	845	+ if (IS_ERR(rreq)) {
	846	+ ret = PTR_ERR(rreq);
	847	+ goto alloc_error;
850	848	}
851	849
852	850	if (ops->begin_cache_operation) {
@@ -887,6 +885,11 @@ int netfs_readpage(struct file *file, · 34 unmodified lines
887	885	out:
888	886	netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
889	887	return ret;
	888	+alloc_error:
	889	+ if (netfs_priv)
	890	+ ops->cleanup(folio_file_mapping(folio), netfs_priv);
	891	+ folio_unlock(folio);
	892	+ return ret;
890	893	}
891	894	EXPORT_SYMBOL(netfs_readpage);
892	895
@@ -1007,12 +1010,13 @@ retry: · 114 unmodified lines
1007	1010	goto have_folio_no_wait;
1008	1011	}
1009	1012
1010		− ret = -ENOMEM;
1011	1013	rreq = netfs_alloc_request(mapping, file, ops, netfs_priv,
1012	1014	folio_file_pos(folio), folio_size(folio),
1013	1015	NETFS_READ_FOR_WRITE);
1014		− if (!rreq)
	1016	+ if (IS_ERR(rreq)) {
	1017	+ ret = PTR_ERR(rreq);
1015	1018	goto error;
	1019	+ }
1016	1020	rreq->no_unlock_folio = folio_index(folio);
1017	1021	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
1018	1022	netfs_priv = NULL;

include/linux/netfs.h+1−1

@@ -193,7 +193,7 @@ struct netfs_io_request { · 192 unmodified lines
193	193	*/
194	194	struct netfs_request_ops {
195	195	bool (is_cache_enabled)(struct inode inode);
196		− void (init_request)(struct netfs_io_request rreq, struct file *file);
	196	+ int (init_request)(struct netfs_io_request rreq, struct file *file);
197	197	int (begin_cache_operation)(struct netfs_io_request rreq);
198	198	void (expand_readahead)(struct netfs_io_request rreq);
199	199	bool (clamp_length)(struct netfs_io_subrequest subreq);

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

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