[mirror_ubuntu-jammy-kernel.git] / fs / afs / fs_operation.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* Fileserver-directed operation handling.
 *
 * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include "internal.h"

static atomic_t afs_operation_debug_counter;

/*
 * Create an operation against a volume.
 */
struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *volume)
{
	struct afs_operation *op;

	_enter("");

	op = kzalloc(sizeof(*op), GFP_KERNEL);
	if (!op)
		return ERR_PTR(-ENOMEM);

	if (!key) {
		key = afs_request_key(volume->cell);
		if (IS_ERR(key)) {
			kfree(op);
			return ERR_CAST(key);
		}
	} else {
		key_get(key);
	}

	op->key		= key;
	op->volume	= afs_get_volume(volume);
	op->net		= volume->cell->net;
	op->cb_v_break	= volume->cb_v_break;
	op->debug_id	= atomic_inc_return(&afs_operation_debug_counter);
	op->error	= -EDESTADDRREQ;
	op->ac.error	= SHRT_MAX;

	_leave(" = [op=%08x]", op->debug_id);
	return op;
}

/*
 * Lock the vnode(s) being operated upon.
 */
static bool afs_get_io_locks(struct afs_operation *op)
{
	struct afs_vnode *vnode = op->file[0].vnode;
	struct afs_vnode *vnode2 = op->file[1].vnode;

	_enter("");

	if (op->flags & AFS_OPERATION_UNINTR) {
		mutex_lock(&vnode->io_lock);
		op->flags |= AFS_OPERATION_LOCK_0;
		_leave(" = t [1]");
		return true;
	}

	if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2)
		vnode2 = NULL;

	if (vnode2 > vnode)
		swap(vnode, vnode2);

	if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
		op->error = -EINTR;
		op->flags |= AFS_OPERATION_STOP;
		_leave(" = f [I 0]");
		return false;
	}
	op->flags |= AFS_OPERATION_LOCK_0;

	if (vnode2) {
		if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
			op->error = -EINTR;
			op->flags |= AFS_OPERATION_STOP;
			mutex_unlock(&vnode->io_lock);
			op->flags &= ~AFS_OPERATION_LOCK_0;
			_leave(" = f [I 1]");
			return false;
		}
		op->flags |= AFS_OPERATION_LOCK_1;
	}

	_leave(" = t [2]");
	return true;
}

static void afs_drop_io_locks(struct afs_operation *op)
{
	struct afs_vnode *vnode = op->file[0].vnode;
	struct afs_vnode *vnode2 = op->file[1].vnode;

	_enter("");

	if (op->flags & AFS_OPERATION_LOCK_1)
		mutex_unlock(&vnode2->io_lock);
	if (op->flags & AFS_OPERATION_LOCK_0)
		mutex_unlock(&vnode->io_lock);
}

static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp,
			      unsigned int index)
{
	struct afs_vnode *vnode = vp->vnode;

	if (vnode) {
		vp->fid			= vnode->fid;
		vp->dv_before		= vnode->status.data_version;
		vp->cb_break_before	= afs_calc_vnode_cb_break(vnode);
		if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
			op->flags	|= AFS_OPERATION_CUR_ONLY;
	}

	if (vp->fid.vnode)
		_debug("PREP[%u] {%llx:%llu.%u}",
		       index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
}

/*
 * Begin an operation on the fileserver.
 *
 * Fileserver operations are serialised on the server by vnode, so we serialise
 * them here also using the io_lock.
 */
bool afs_begin_vnode_operation(struct afs_operation *op)
{
	struct afs_vnode *vnode = op->file[0].vnode;

	ASSERT(vnode);

	_enter("");

	if (op->file[0].need_io_lock)
		if (!afs_get_io_locks(op))
			return false;

	read_seqlock_excl(&vnode->cb_lock);
	op->cbi = afs_get_cb_interest(
		rcu_dereference_protected(vnode->cb_interest,
					  lockdep_is_held(&vnode->cb_lock.lock)));
	read_sequnlock_excl(&vnode->cb_lock);

	afs_prepare_vnode(op, &op->file[0], 0);
	afs_prepare_vnode(op, &op->file[1], 1);
	op->cb_v_break = op->volume->cb_v_break;
	_leave(" = true");
	return true;
}

/*
 * Tidy up a filesystem cursor and unlock the vnode.
 */
static void afs_end_vnode_operation(struct afs_operation *op)
{
	_enter("");

	if (op->error == -EDESTADDRREQ ||
	    op->error == -EADDRNOTAVAIL ||
	    op->error == -ENETUNREACH ||
	    op->error == -EHOSTUNREACH)
		afs_dump_edestaddrreq(op);

	afs_drop_io_locks(op);

	if (op->error == -ECONNABORTED)
		op->error = afs_abort_to_error(op->ac.abort_code);
}

/*
 * Wait for an in-progress operation to complete.
 */
void afs_wait_for_operation(struct afs_operation *op)
{
	_enter("");

	while (afs_select_fileserver(op)) {
		op->cb_s_break = op->cbi->server->cb_s_break;
		if (test_bit(AFS_SERVER_FL_IS_YFS, &op->cbi->server->flags) &&
		    op->ops->issue_yfs_rpc)
			op->ops->issue_yfs_rpc(op);
		else
			op->ops->issue_afs_rpc(op);

		op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
	}

	if (op->error == 0) {
		_debug("success");
		op->ops->success(op);
	}

	afs_end_vnode_operation(op);

	if (op->error == 0 && op->ops->edit_dir) {
		_debug("edit_dir");
		op->ops->edit_dir(op);
	}
	_leave("");
}

/*
 * Dispose of an operation.
 */
int afs_put_operation(struct afs_operation *op)
{
	int i, ret = op->error;

	_enter("op=%08x,%d", op->debug_id, ret);

	if (op->ops && op->ops->put)
		op->ops->put(op);
	if (op->file[0].put_vnode)
		iput(&op->file[0].vnode->vfs_inode);
	if (op->file[1].put_vnode)
		iput(&op->file[1].vnode->vfs_inode);

	if (op->more_files) {
		for (i = 0; i < op->nr_files - 2; i++)
			if (op->more_files[i].put_vnode)
				iput(&op->more_files[i].vnode->vfs_inode);
		kfree(op->more_files);
	}

	afs_end_cursor(&op->ac);
	afs_put_cb_interest(op->net, op->cbi);
	afs_put_serverlist(op->net, op->server_list);
	afs_put_volume(op->net, op->volume);
	kfree(op);
	return ret;
}

int afs_do_sync_operation(struct afs_operation *op)
{
	afs_begin_vnode_operation(op);
	afs_wait_for_operation(op);
	return afs_put_operation(op);
}
Commit	Line	Data
e49c7b2f DH	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/* Fileserver-directed operation handling.
	3	*
	4	* Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/slab.h>
	10	#include <linux/fs.h>
	11	#include "internal.h"
	12
	13	static atomic_t afs_operation_debug_counter;
	14
	15	/*
	16	* Create an operation against a volume.
	17	*/
	18	struct afs_operation afs_alloc_operation(struct key key, struct afs_volume *volume)
	19	{
	20	struct afs_operation *op;
	21
	22	_enter("");
	23
	24	op = kzalloc(sizeof(*op), GFP_KERNEL);
	25	if (!op)
	26	return ERR_PTR(-ENOMEM);
	27
	28	if (!key) {
	29	key = afs_request_key(volume->cell);
	30	if (IS_ERR(key)) {
	31	kfree(op);
	32	return ERR_CAST(key);
	33	}
	34	} else {
	35	key_get(key);
	36	}
	37
	38	op->key = key;
	39	op->volume = afs_get_volume(volume);
	40	op->net = volume->cell->net;
	41	op->cb_v_break = volume->cb_v_break;
	42	op->debug_id = atomic_inc_return(&afs_operation_debug_counter);
	43	op->error = -EDESTADDRREQ;
	44	op->ac.error = SHRT_MAX;
	45
	46	_leave(" = [op=%08x]", op->debug_id);
	47	return op;
	48	}
	49
	50	/*
	51	* Lock the vnode(s) being operated upon.
	52	*/
	53	static bool afs_get_io_locks(struct afs_operation *op)
	54	{
	55	struct afs_vnode *vnode = op->file[0].vnode;
	56	struct afs_vnode *vnode2 = op->file[1].vnode;
	57
	58	_enter("");
	59
	60	if (op->flags & AFS_OPERATION_UNINTR) {
	61	mutex_lock(&vnode->io_lock);
	62	op->flags \|= AFS_OPERATION_LOCK_0;
	63	_leave(" = t [1]");
	64	return true;
65	}
66
67	if (!vnode2 \|\| !op->file[1].need_io_lock \|\| vnode == vnode2)
68	vnode2 = NULL;
69
70	if (vnode2 > vnode)
71	swap(vnode, vnode2);
72
73	if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
74	op->error = -EINTR;
75	op->flags \|= AFS_OPERATION_STOP;
76	_leave(" = f [I 0]");
77	return false;
78	}
79	op->flags \|= AFS_OPERATION_LOCK_0;
80
81	if (vnode2) {
82	if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
83	op->error = -EINTR;
84	op->flags \|= AFS_OPERATION_STOP;
85	mutex_unlock(&vnode->io_lock);
86	op->flags &= ~AFS_OPERATION_LOCK_0;
87	_leave(" = f [I 1]");
88	return false;
89	}
90	op->flags \|= AFS_OPERATION_LOCK_1;
91	}
92
93	_leave(" = t [2]");
94	return true;
95	}
96
97	static void afs_drop_io_locks(struct afs_operation *op)
98	{
99	struct afs_vnode *vnode = op->file[0].vnode;
100	struct afs_vnode *vnode2 = op->file[1].vnode;
101
102	_enter("");
103
104	if (op->flags & AFS_OPERATION_LOCK_1)
105	mutex_unlock(&vnode2->io_lock);
106	if (op->flags & AFS_OPERATION_LOCK_0)
107	mutex_unlock(&vnode->io_lock);
108	}
109
110	static void afs_prepare_vnode(struct afs_operation op, struct afs_vnode_param vp,
111	unsigned int index)
112	{
113	struct afs_vnode *vnode = vp->vnode;
114
115	if (vnode) {
116	vp->fid = vnode->fid;
117	vp->dv_before = vnode->status.data_version;
118	vp->cb_break_before = afs_calc_vnode_cb_break(vnode);
119	if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
120	op->flags \|= AFS_OPERATION_CUR_ONLY;
121	}
122
123	if (vp->fid.vnode)
124	_debug("PREP[%u] {%llx:%llu.%u}",
125	index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
126	}
127
128	/*
129	* Begin an operation on the fileserver.
130	*
131	* Fileserver operations are serialised on the server by vnode, so we serialise
132	* them here also using the io_lock.
133	*/
134	bool afs_begin_vnode_operation(struct afs_operation *op)
135	{
136	struct afs_vnode *vnode = op->file[0].vnode;
137
138	ASSERT(vnode);
139
140	_enter("");
141
142	if (op->file[0].need_io_lock)
143	if (!afs_get_io_locks(op))
144	return false;
145
146	read_seqlock_excl(&vnode->cb_lock);
147	op->cbi = afs_get_cb_interest(
148	rcu_dereference_protected(vnode->cb_interest,
149	lockdep_is_held(&vnode->cb_lock.lock)));
150	read_sequnlock_excl(&vnode->cb_lock);
151
152	afs_prepare_vnode(op, &op->file[0], 0);
153	afs_prepare_vnode(op, &op->file[1], 1);
154	op->cb_v_break = op->volume->cb_v_break;
155	_leave(" = true");
156	return true;
157	}
158
159	/*
160	* Tidy up a filesystem cursor and unlock the vnode.
161	*/
162	static void afs_end_vnode_operation(struct afs_operation *op)
163	{
164	_enter("");
165
166	if (op->error == -EDESTADDRREQ \|\|
167	op->error == -EADDRNOTAVAIL \|\|
168	op->error == -ENETUNREACH \|\|
169	op->error == -EHOSTUNREACH)
170	afs_dump_edestaddrreq(op);
171
172	afs_drop_io_locks(op);
173
174	if (op->error == -ECONNABORTED)
175	op->error = afs_abort_to_error(op->ac.abort_code);
176	}
177
178	/*
179	* Wait for an in-progress operation to complete.
180	*/
181	void afs_wait_for_operation(struct afs_operation *op)
182	{
183	_enter("");
184
185	while (afs_select_fileserver(op)) {
186	op->cb_s_break = op->cbi->server->cb_s_break;
187	if (test_bit(AFS_SERVER_FL_IS_YFS, &op->cbi->server->flags) &&
188	op->ops->issue_yfs_rpc)
189	op->ops->issue_yfs_rpc(op);
190	else
191	op->ops->issue_afs_rpc(op);
192
193	op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
194	}
195
196	if (op->error == 0) {
197	_debug("success");
198	op->ops->success(op);
199	}
200
201	afs_end_vnode_operation(op);
202
203	if (op->error == 0 && op->ops->edit_dir) {
204	_debug("edit_dir");
205	op->ops->edit_dir(op);
206	}
207	_leave("");
208	}
209
210	/*
211	* Dispose of an operation.
212	*/
213	int afs_put_operation(struct afs_operation *op)
214	{
215	int i, ret = op->error;
216
217	_enter("op=%08x,%d", op->debug_id, ret);
218
219	if (op->ops && op->ops->put)
220	op->ops->put(op);
221	if (op->file[0].put_vnode)
222	iput(&op->file[0].vnode->vfs_inode);
223	if (op->file[1].put_vnode)
224	iput(&op->file[1].vnode->vfs_inode);
225
226	if (op->more_files) {
227	for (i = 0; i < op->nr_files - 2; i++)
228	if (op->more_files[i].put_vnode)
229	iput(&op->more_files[i].vnode->vfs_inode);
230	kfree(op->more_files);
231	}
232
233	afs_end_cursor(&op->ac);
234	afs_put_cb_interest(op->net, op->cbi);
235	afs_put_serverlist(op->net, op->server_list);
236	afs_put_volume(op->net, op->volume);
237	kfree(op);
238	return ret;
239	}
240
241	int afs_do_sync_operation(struct afs_operation *op)
242	{
243	afs_begin_vnode_operation(op);
244	afs_wait_for_operation(op);
245	return afs_put_operation(op);
246	}