1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_inode.h"
14#include "xfs_quota.h"
15#include "xfs_trans.h"
16#include "xfs_buf_item.h"
17#include "xfs_trans_priv.h"
18#include "xfs_qm.h"
19#include "xfs_log.h"
20
21static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
22{
23	return container_of(lip, struct xfs_dq_logitem, qli_item);
24}
25
26/*
27 * returns the number of iovecs needed to log the given dquot item.
28 */
29STATIC void
30xfs_qm_dquot_logitem_size(
31	struct xfs_log_item	*lip,
32	int			*nvecs,
33	int			*nbytes)
34{
35	*nvecs += 2;
36	*nbytes += sizeof(struct xfs_dq_logformat) +
37		   sizeof(struct xfs_disk_dquot);
38}
39
40/*
41 * fills in the vector of log iovecs for the given dquot log item.
42 */
43STATIC void
44xfs_qm_dquot_logitem_format(
45	struct xfs_log_item	*lip,
46	struct xfs_log_vec	*lv)
47{
48	struct xfs_disk_dquot	ddq;
49	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);
50	struct xfs_log_iovec	*vecp = NULL;
51	struct xfs_dq_logformat	*qlf;
52
53	qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QFORMAT);
54	qlf->qlf_type = XFS_LI_DQUOT;
55	qlf->qlf_size = 2;
56	qlf->qlf_id = qlip->qli_dquot->q_id;
57	qlf->qlf_blkno = qlip->qli_dquot->q_blkno;
58	qlf->qlf_len = 1;
59	qlf->qlf_boffset = qlip->qli_dquot->q_bufoffset;
60	xlog_finish_iovec(lv, vecp, sizeof(struct xfs_dq_logformat));
61
62	xfs_dquot_to_disk(&ddq, qlip->qli_dquot);
63
64	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_DQUOT, &ddq,
65			sizeof(struct xfs_disk_dquot));
66}
67
68/*
69 * Increment the pin count of the given dquot.
70 */
71STATIC void
72xfs_qm_dquot_logitem_pin(
73	struct xfs_log_item	*lip)
74{
75	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
76
77	ASSERT(XFS_DQ_IS_LOCKED(dqp));
78	atomic_inc(&dqp->q_pincount);
79}
80
81/*
82 * Decrement the pin count of the given dquot, and wake up
83 * anyone in xfs_dqwait_unpin() if the count goes to 0.	 The
84 * dquot must have been previously pinned with a call to
85 * xfs_qm_dquot_logitem_pin().
86 */
87STATIC void
88xfs_qm_dquot_logitem_unpin(
89	struct xfs_log_item	*lip,
90	int			remove)
91{
92	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
93
94	ASSERT(atomic_read(&dqp->q_pincount) > 0);
95	if (atomic_dec_and_test(&dqp->q_pincount))
96		wake_up(&dqp->q_pinwait);
97}
98
99/*
100 * This is called to wait for the given dquot to be unpinned.
101 * Most of these pin/unpin routines are plagiarized from inode code.
102 */
103void
104xfs_qm_dqunpin_wait(
105	struct xfs_dquot	*dqp)
106{
107	ASSERT(XFS_DQ_IS_LOCKED(dqp));
108	if (atomic_read(&dqp->q_pincount) == 0)
109		return;
110
111	/*
112	 * Give the log a push so we don't wait here too long.
113	 */
114	xfs_log_force(dqp->q_mount, 0);
115	wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));
116}
117
118STATIC uint
119xfs_qm_dquot_logitem_push(
120	struct xfs_log_item	*lip,
121	struct list_head	*buffer_list)
122		__releases(&lip->li_ailp->ail_lock)
123		__acquires(&lip->li_ailp->ail_lock)
124{
125	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
126	struct xfs_buf		*bp = lip->li_buf;
127	uint			rval = XFS_ITEM_SUCCESS;
128	int			error;
129
130	if (atomic_read(&dqp->q_pincount) > 0)
131		return XFS_ITEM_PINNED;
132
133	if (!xfs_dqlock_nowait(dqp))
134		return XFS_ITEM_LOCKED;
135
136	/*
137	 * Re-check the pincount now that we stabilized the value by
138	 * taking the quota lock.
139	 */
140	if (atomic_read(&dqp->q_pincount) > 0) {
141		rval = XFS_ITEM_PINNED;
142		goto out_unlock;
143	}
144
145	/*
146	 * Someone else is already flushing the dquot.  Nothing we can do
147	 * here but wait for the flush to finish and remove the item from
148	 * the AIL.
149	 */
150	if (!xfs_dqflock_nowait(dqp)) {
151		rval = XFS_ITEM_FLUSHING;
152		goto out_unlock;
153	}
154
155	spin_unlock(&lip->li_ailp->ail_lock);
156
157	error = xfs_qm_dqflush(dqp, &bp);
158	if (!error) {
159		if (!xfs_buf_delwri_queue(bp, buffer_list))
160			rval = XFS_ITEM_FLUSHING;
161		xfs_buf_relse(bp);
162	} else if (error == -EAGAIN)
163		rval = XFS_ITEM_LOCKED;
164
165	spin_lock(&lip->li_ailp->ail_lock);
166out_unlock:
167	xfs_dqunlock(dqp);
168	return rval;
169}
170
171STATIC void
172xfs_qm_dquot_logitem_release(
173	struct xfs_log_item	*lip)
174{
175	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
176
177	ASSERT(XFS_DQ_IS_LOCKED(dqp));
178
179	/*
180	 * dquots are never 'held' from getting unlocked at the end of
181	 * a transaction.  Their locking and unlocking is hidden inside the
182	 * transaction layer, within trans_commit. Hence, no LI_HOLD flag
183	 * for the logitem.
184	 */
185	xfs_dqunlock(dqp);
186}
187
188STATIC void
189xfs_qm_dquot_logitem_committing(
190	struct xfs_log_item	*lip,
191	xfs_csn_t		seq)
192{
193	return xfs_qm_dquot_logitem_release(lip);
194}
195
196static const struct xfs_item_ops xfs_dquot_item_ops = {
197	.iop_size	= xfs_qm_dquot_logitem_size,
198	.iop_format	= xfs_qm_dquot_logitem_format,
199	.iop_pin	= xfs_qm_dquot_logitem_pin,
200	.iop_unpin	= xfs_qm_dquot_logitem_unpin,
201	.iop_release	= xfs_qm_dquot_logitem_release,
202	.iop_committing	= xfs_qm_dquot_logitem_committing,
203	.iop_push	= xfs_qm_dquot_logitem_push,
204};
205
206/*
207 * Initialize the dquot log item for a newly allocated dquot.
208 * The dquot isn't locked at this point, but it isn't on any of the lists
209 * either, so we don't care.
210 */
211void
212xfs_qm_dquot_logitem_init(
213	struct xfs_dquot	*dqp)
214{
215	struct xfs_dq_logitem	*lp = &dqp->q_logitem;
216
217	xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
218					&xfs_dquot_item_ops);
219	lp->qli_dquot = dqp;
220}
221