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 
DQUOT_ITEM(struct xfs_log_item * lip)21 static 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  */
29 STATIC void
xfs_qm_dquot_logitem_size(struct xfs_log_item * lip,int * nvecs,int * nbytes)30 xfs_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  */
43 STATIC void
xfs_qm_dquot_logitem_format(struct xfs_log_item * lip,struct xfs_log_vec * lv)44 xfs_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  */
71 STATIC void
xfs_qm_dquot_logitem_pin(struct xfs_log_item * lip)72 xfs_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  */
87 STATIC void
xfs_qm_dquot_logitem_unpin(struct xfs_log_item * lip,int remove)88 xfs_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  */
103 void
xfs_qm_dqunpin_wait(struct xfs_dquot * dqp)104 xfs_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 
118 STATIC uint
xfs_qm_dquot_logitem_push(struct xfs_log_item * lip,struct list_head * buffer_list)119 xfs_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);
166 out_unlock:
167 	xfs_dqunlock(dqp);
168 	return rval;
169 }
170 
171 STATIC void
xfs_qm_dquot_logitem_release(struct xfs_log_item * lip)172 xfs_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 
188 STATIC void
xfs_qm_dquot_logitem_committing(struct xfs_log_item * lip,xfs_csn_t seq)189 xfs_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 
196 static 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  */
211 void
xfs_qm_dquot_logitem_init(struct xfs_dquot * dqp)212 xfs_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