xref: /linux/fs/xfs/xfs_dquot_item.c (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs_platform.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 #include "xfs_error.h"
21 
22 static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
23 {
24 	return container_of(lip, struct xfs_dq_logitem, qli_item);
25 }
26 
27 /*
28  * returns the number of iovecs needed to log the given dquot item.
29  */
30 STATIC void
31 xfs_qm_dquot_logitem_size(
32 	struct xfs_log_item	*lip,
33 	int			*nvecs,
34 	int			*nbytes)
35 {
36 	*nvecs += 2;
37 	*nbytes += sizeof(struct xfs_dq_logformat) +
38 		   sizeof(struct xfs_disk_dquot);
39 }
40 
41 /*
42  * fills in the vector of log iovecs for the given dquot log item.
43  */
44 STATIC void
45 xfs_qm_dquot_logitem_format(
46 	struct xfs_log_item	*lip,
47 	struct xlog_format_buf	*lfb)
48 {
49 	struct xfs_disk_dquot	ddq;
50 	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);
51 	struct xfs_dq_logformat	*qlf;
52 
53 	qlf = xlog_format_start(lfb, 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_format_commit(lfb, sizeof(struct xfs_dq_logformat));
61 
62 	xfs_dquot_to_disk(&ddq, qlip->qli_dquot);
63 
64 	xlog_format_copy(lfb, 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
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
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
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
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_dq_logitem	*qlip = DQUOT_ITEM(lip);
126 	struct xfs_dquot	*dqp = qlip->qli_dquot;
127 	struct xfs_buf		*bp;
128 	uint			rval = XFS_ITEM_SUCCESS;
129 	int			error;
130 
131 	if (atomic_read(&dqp->q_pincount) > 0)
132 		return XFS_ITEM_PINNED;
133 
134 	if (!mutex_trylock(&dqp->q_qlock))
135 		return XFS_ITEM_LOCKED;
136 
137 	/*
138 	 * Re-check the pincount now that we stabilized the value by
139 	 * taking the quota lock.
140 	 */
141 	if (atomic_read(&dqp->q_pincount) > 0) {
142 		rval = XFS_ITEM_PINNED;
143 		goto out_unlock;
144 	}
145 
146 	/*
147 	 * Someone else is already flushing the dquot.  Nothing we can do
148 	 * here but wait for the flush to finish and remove the item from
149 	 * the AIL.
150 	 */
151 	if (!xfs_dqflock_nowait(dqp)) {
152 		rval = XFS_ITEM_FLUSHING;
153 		goto out_unlock;
154 	}
155 
156 	spin_unlock(&lip->li_ailp->ail_lock);
157 
158 	error = xfs_dquot_use_attached_buf(dqp, &bp);
159 	if (error == -EAGAIN) {
160 		xfs_dqfunlock(dqp);
161 		rval = XFS_ITEM_LOCKED;
162 		goto out_relock_ail;
163 	}
164 
165 	/*
166 	 * dqflush completes dqflock on error, and the delwri ioend does it on
167 	 * success.
168 	 */
169 	error = xfs_qm_dqflush(dqp, bp);
170 	if (!error) {
171 		if (!xfs_buf_delwri_queue(bp, buffer_list))
172 			rval = XFS_ITEM_FLUSHING;
173 	}
174 	xfs_buf_relse(bp);
175 
176 out_relock_ail:
177 	spin_lock(&lip->li_ailp->ail_lock);
178 out_unlock:
179 	mutex_unlock(&dqp->q_qlock);
180 	return rval;
181 }
182 
183 STATIC void
184 xfs_qm_dquot_logitem_release(
185 	struct xfs_log_item	*lip)
186 {
187 	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
188 
189 	ASSERT(XFS_DQ_IS_LOCKED(dqp));
190 
191 	/*
192 	 * dquots are never 'held' from getting unlocked at the end of
193 	 * a transaction.  Their locking and unlocking is hidden inside the
194 	 * transaction layer, within trans_commit. Hence, no LI_HOLD flag
195 	 * for the logitem.
196 	 */
197 	mutex_unlock(&dqp->q_qlock);
198 }
199 
200 STATIC void
201 xfs_qm_dquot_logitem_committing(
202 	struct xfs_log_item	*lip,
203 	xfs_csn_t		seq)
204 {
205 	return xfs_qm_dquot_logitem_release(lip);
206 }
207 
208 #ifdef DEBUG_EXPENSIVE
209 static void
210 xfs_qm_dquot_logitem_precommit_check(
211 	struct xfs_dquot	*dqp)
212 {
213 	struct xfs_mount	*mp = dqp->q_mount;
214 	struct xfs_disk_dquot	ddq = { };
215 	xfs_failaddr_t		fa;
216 
217 	xfs_dquot_to_disk(&ddq, dqp);
218 	fa = xfs_dquot_verify(mp, &ddq, dqp->q_id);
219 	if (fa) {
220 		XFS_CORRUPTION_ERROR("Bad dquot during logging",
221 				XFS_ERRLEVEL_LOW, mp, &ddq, sizeof(ddq));
222 		xfs_alert(mp,
223  "Metadata corruption detected at %pS, dquot 0x%x",
224 				fa, dqp->q_id);
225 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
226 		ASSERT(fa == NULL);
227 	}
228 }
229 #else
230 # define xfs_qm_dquot_logitem_precommit_check(...)	((void)0)
231 #endif
232 
233 static int
234 xfs_qm_dquot_logitem_precommit(
235 	struct xfs_trans	*tp,
236 	struct xfs_log_item	*lip)
237 {
238 	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);
239 	struct xfs_dquot	*dqp = qlip->qli_dquot;
240 
241 	xfs_qm_dquot_logitem_precommit_check(dqp);
242 
243 	return xfs_dquot_attach_buf(tp, dqp);
244 }
245 
246 static const struct xfs_item_ops xfs_dquot_item_ops = {
247 	.iop_size	= xfs_qm_dquot_logitem_size,
248 	.iop_precommit	= xfs_qm_dquot_logitem_precommit,
249 	.iop_format	= xfs_qm_dquot_logitem_format,
250 	.iop_pin	= xfs_qm_dquot_logitem_pin,
251 	.iop_unpin	= xfs_qm_dquot_logitem_unpin,
252 	.iop_release	= xfs_qm_dquot_logitem_release,
253 	.iop_committing	= xfs_qm_dquot_logitem_committing,
254 	.iop_push	= xfs_qm_dquot_logitem_push,
255 };
256 
257 /*
258  * Initialize the dquot log item for a newly allocated dquot.
259  * The dquot isn't locked at this point, but it isn't on any of the lists
260  * either, so we don't care.
261  */
262 void
263 xfs_qm_dquot_logitem_init(
264 	struct xfs_dquot	*dqp)
265 {
266 	struct xfs_dq_logitem	*lp = &dqp->q_logitem;
267 
268 	xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
269 					&xfs_dquot_item_ops);
270 	spin_lock_init(&lp->qli_lock);
271 	lp->qli_dquot = dqp;
272 	lp->qli_dirty = false;
273 }
274