Merge branch 'for-linus-sa1100' of git://git.armlinux.org.uk/~rmk/linux-arm
[platform/kernel/linux-rpi.git] / fs / xfs / xfs_dquot_item.c
1 /*
2  * Copyright (c) 2000-2003 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_format.h"
21 #include "xfs_log_format.h"
22 #include "xfs_trans_resv.h"
23 #include "xfs_mount.h"
24 #include "xfs_inode.h"
25 #include "xfs_quota.h"
26 #include "xfs_error.h"
27 #include "xfs_trans.h"
28 #include "xfs_buf_item.h"
29 #include "xfs_trans_priv.h"
30 #include "xfs_qm.h"
31 #include "xfs_log.h"
32
33 static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
34 {
35         return container_of(lip, struct xfs_dq_logitem, qli_item);
36 }
37
38 /*
39  * returns the number of iovecs needed to log the given dquot item.
40  */
41 STATIC void
42 xfs_qm_dquot_logitem_size(
43         struct xfs_log_item     *lip,
44         int                     *nvecs,
45         int                     *nbytes)
46 {
47         *nvecs += 2;
48         *nbytes += sizeof(struct xfs_dq_logformat) +
49                    sizeof(struct xfs_disk_dquot);
50 }
51
52 /*
53  * fills in the vector of log iovecs for the given dquot log item.
54  */
55 STATIC void
56 xfs_qm_dquot_logitem_format(
57         struct xfs_log_item     *lip,
58         struct xfs_log_vec      *lv)
59 {
60         struct xfs_dq_logitem   *qlip = DQUOT_ITEM(lip);
61         struct xfs_log_iovec    *vecp = NULL;
62         struct xfs_dq_logformat *qlf;
63
64         qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QFORMAT);
65         qlf->qlf_type = XFS_LI_DQUOT;
66         qlf->qlf_size = 2;
67         qlf->qlf_id = be32_to_cpu(qlip->qli_dquot->q_core.d_id);
68         qlf->qlf_blkno = qlip->qli_dquot->q_blkno;
69         qlf->qlf_len = 1;
70         qlf->qlf_boffset = qlip->qli_dquot->q_bufoffset;
71         xlog_finish_iovec(lv, vecp, sizeof(struct xfs_dq_logformat));
72
73         xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_DQUOT,
74                         &qlip->qli_dquot->q_core,
75                         sizeof(struct xfs_disk_dquot));
76 }
77
78 /*
79  * Increment the pin count of the given dquot.
80  */
81 STATIC void
82 xfs_qm_dquot_logitem_pin(
83         struct xfs_log_item     *lip)
84 {
85         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
86
87         ASSERT(XFS_DQ_IS_LOCKED(dqp));
88         atomic_inc(&dqp->q_pincount);
89 }
90
91 /*
92  * Decrement the pin count of the given dquot, and wake up
93  * anyone in xfs_dqwait_unpin() if the count goes to 0.  The
94  * dquot must have been previously pinned with a call to
95  * xfs_qm_dquot_logitem_pin().
96  */
97 STATIC void
98 xfs_qm_dquot_logitem_unpin(
99         struct xfs_log_item     *lip,
100         int                     remove)
101 {
102         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
103
104         ASSERT(atomic_read(&dqp->q_pincount) > 0);
105         if (atomic_dec_and_test(&dqp->q_pincount))
106                 wake_up(&dqp->q_pinwait);
107 }
108
109 STATIC xfs_lsn_t
110 xfs_qm_dquot_logitem_committed(
111         struct xfs_log_item     *lip,
112         xfs_lsn_t               lsn)
113 {
114         /*
115          * We always re-log the entire dquot when it becomes dirty,
116          * so, the latest copy _is_ the only one that matters.
117          */
118         return lsn;
119 }
120
121 /*
122  * This is called to wait for the given dquot to be unpinned.
123  * Most of these pin/unpin routines are plagiarized from inode code.
124  */
125 void
126 xfs_qm_dqunpin_wait(
127         struct xfs_dquot        *dqp)
128 {
129         ASSERT(XFS_DQ_IS_LOCKED(dqp));
130         if (atomic_read(&dqp->q_pincount) == 0)
131                 return;
132
133         /*
134          * Give the log a push so we don't wait here too long.
135          */
136         xfs_log_force(dqp->q_mount, 0);
137         wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));
138 }
139
140 /*
141  * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer
142  * have been failed during writeback
143  *
144  * this informs the AIL that the dquot is already flush locked on the next push,
145  * and acquires a hold on the buffer to ensure that it isn't reclaimed before
146  * dirty data makes it to disk.
147  */
148 STATIC void
149 xfs_dquot_item_error(
150         struct xfs_log_item     *lip,
151         struct xfs_buf          *bp)
152 {
153         ASSERT(!completion_done(&DQUOT_ITEM(lip)->qli_dquot->q_flush));
154         xfs_set_li_failed(lip, bp);
155 }
156
157 STATIC uint
158 xfs_qm_dquot_logitem_push(
159         struct xfs_log_item     *lip,
160         struct list_head        *buffer_list)
161                 __releases(&lip->li_ailp->ail_lock)
162                 __acquires(&lip->li_ailp->ail_lock)
163 {
164         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
165         struct xfs_buf          *bp = lip->li_buf;
166         uint                    rval = XFS_ITEM_SUCCESS;
167         int                     error;
168
169         if (atomic_read(&dqp->q_pincount) > 0)
170                 return XFS_ITEM_PINNED;
171
172         /*
173          * The buffer containing this item failed to be written back
174          * previously. Resubmit the buffer for IO
175          */
176         if (lip->li_flags & XFS_LI_FAILED) {
177                 if (!xfs_buf_trylock(bp))
178                         return XFS_ITEM_LOCKED;
179
180                 if (!xfs_buf_resubmit_failed_buffers(bp, buffer_list))
181                         rval = XFS_ITEM_FLUSHING;
182
183                 xfs_buf_unlock(bp);
184                 return rval;
185         }
186
187         if (!xfs_dqlock_nowait(dqp))
188                 return XFS_ITEM_LOCKED;
189
190         /*
191          * Re-check the pincount now that we stabilized the value by
192          * taking the quota lock.
193          */
194         if (atomic_read(&dqp->q_pincount) > 0) {
195                 rval = XFS_ITEM_PINNED;
196                 goto out_unlock;
197         }
198
199         /*
200          * Someone else is already flushing the dquot.  Nothing we can do
201          * here but wait for the flush to finish and remove the item from
202          * the AIL.
203          */
204         if (!xfs_dqflock_nowait(dqp)) {
205                 rval = XFS_ITEM_FLUSHING;
206                 goto out_unlock;
207         }
208
209         spin_unlock(&lip->li_ailp->ail_lock);
210
211         error = xfs_qm_dqflush(dqp, &bp);
212         if (error) {
213                 xfs_warn(dqp->q_mount, "%s: push error %d on dqp "PTR_FMT,
214                         __func__, error, dqp);
215         } else {
216                 if (!xfs_buf_delwri_queue(bp, buffer_list))
217                         rval = XFS_ITEM_FLUSHING;
218                 xfs_buf_relse(bp);
219         }
220
221         spin_lock(&lip->li_ailp->ail_lock);
222 out_unlock:
223         xfs_dqunlock(dqp);
224         return rval;
225 }
226
227 /*
228  * Unlock the dquot associated with the log item.
229  * Clear the fields of the dquot and dquot log item that
230  * are specific to the current transaction.  If the
231  * hold flags is set, do not unlock the dquot.
232  */
233 STATIC void
234 xfs_qm_dquot_logitem_unlock(
235         struct xfs_log_item     *lip)
236 {
237         struct xfs_dquot        *dqp = DQUOT_ITEM(lip)->qli_dquot;
238
239         ASSERT(XFS_DQ_IS_LOCKED(dqp));
240
241         /*
242          * Clear the transaction pointer in the dquot
243          */
244         dqp->q_transp = NULL;
245
246         /*
247          * dquots are never 'held' from getting unlocked at the end of
248          * a transaction.  Their locking and unlocking is hidden inside the
249          * transaction layer, within trans_commit. Hence, no LI_HOLD flag
250          * for the logitem.
251          */
252         xfs_dqunlock(dqp);
253 }
254
255 /*
256  * this needs to stamp an lsn into the dquot, I think.
257  * rpc's that look at user dquot's would then have to
258  * push on the dependency recorded in the dquot
259  */
260 STATIC void
261 xfs_qm_dquot_logitem_committing(
262         struct xfs_log_item     *lip,
263         xfs_lsn_t               lsn)
264 {
265 }
266
267 /*
268  * This is the ops vector for dquots
269  */
270 static const struct xfs_item_ops xfs_dquot_item_ops = {
271         .iop_size       = xfs_qm_dquot_logitem_size,
272         .iop_format     = xfs_qm_dquot_logitem_format,
273         .iop_pin        = xfs_qm_dquot_logitem_pin,
274         .iop_unpin      = xfs_qm_dquot_logitem_unpin,
275         .iop_unlock     = xfs_qm_dquot_logitem_unlock,
276         .iop_committed  = xfs_qm_dquot_logitem_committed,
277         .iop_push       = xfs_qm_dquot_logitem_push,
278         .iop_committing = xfs_qm_dquot_logitem_committing,
279         .iop_error      = xfs_dquot_item_error
280 };
281
282 /*
283  * Initialize the dquot log item for a newly allocated dquot.
284  * The dquot isn't locked at this point, but it isn't on any of the lists
285  * either, so we don't care.
286  */
287 void
288 xfs_qm_dquot_logitem_init(
289         struct xfs_dquot        *dqp)
290 {
291         struct xfs_dq_logitem   *lp = &dqp->q_logitem;
292
293         xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
294                                         &xfs_dquot_item_ops);
295         lp->qli_dquot = dqp;
296 }
297
298 /*------------------  QUOTAOFF LOG ITEMS  -------------------*/
299
300 static inline struct xfs_qoff_logitem *QOFF_ITEM(struct xfs_log_item *lip)
301 {
302         return container_of(lip, struct xfs_qoff_logitem, qql_item);
303 }
304
305
306 /*
307  * This returns the number of iovecs needed to log the given quotaoff item.
308  * We only need 1 iovec for an quotaoff item.  It just logs the
309  * quotaoff_log_format structure.
310  */
311 STATIC void
312 xfs_qm_qoff_logitem_size(
313         struct xfs_log_item     *lip,
314         int                     *nvecs,
315         int                     *nbytes)
316 {
317         *nvecs += 1;
318         *nbytes += sizeof(struct xfs_qoff_logitem);
319 }
320
321 STATIC void
322 xfs_qm_qoff_logitem_format(
323         struct xfs_log_item     *lip,
324         struct xfs_log_vec      *lv)
325 {
326         struct xfs_qoff_logitem *qflip = QOFF_ITEM(lip);
327         struct xfs_log_iovec    *vecp = NULL;
328         struct xfs_qoff_logformat *qlf;
329
330         qlf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_QUOTAOFF);
331         qlf->qf_type = XFS_LI_QUOTAOFF;
332         qlf->qf_size = 1;
333         qlf->qf_flags = qflip->qql_flags;
334         xlog_finish_iovec(lv, vecp, sizeof(struct xfs_qoff_logitem));
335 }
336
337 /*
338  * Pinning has no meaning for an quotaoff item, so just return.
339  */
340 STATIC void
341 xfs_qm_qoff_logitem_pin(
342         struct xfs_log_item     *lip)
343 {
344 }
345
346 /*
347  * Since pinning has no meaning for an quotaoff item, unpinning does
348  * not either.
349  */
350 STATIC void
351 xfs_qm_qoff_logitem_unpin(
352         struct xfs_log_item     *lip,
353         int                     remove)
354 {
355 }
356
357 /*
358  * There isn't much you can do to push a quotaoff item.  It is simply
359  * stuck waiting for the log to be flushed to disk.
360  */
361 STATIC uint
362 xfs_qm_qoff_logitem_push(
363         struct xfs_log_item     *lip,
364         struct list_head        *buffer_list)
365 {
366         return XFS_ITEM_LOCKED;
367 }
368
369 /*
370  * Quotaoff items have no locking or pushing, so return failure
371  * so that the caller doesn't bother with us.
372  */
373 STATIC void
374 xfs_qm_qoff_logitem_unlock(
375         struct xfs_log_item     *lip)
376 {
377 }
378
379 /*
380  * The quotaoff-start-item is logged only once and cannot be moved in the log,
381  * so simply return the lsn at which it's been logged.
382  */
383 STATIC xfs_lsn_t
384 xfs_qm_qoff_logitem_committed(
385         struct xfs_log_item     *lip,
386         xfs_lsn_t               lsn)
387 {
388         return lsn;
389 }
390
391 STATIC xfs_lsn_t
392 xfs_qm_qoffend_logitem_committed(
393         struct xfs_log_item     *lip,
394         xfs_lsn_t               lsn)
395 {
396         struct xfs_qoff_logitem *qfe = QOFF_ITEM(lip);
397         struct xfs_qoff_logitem *qfs = qfe->qql_start_lip;
398         struct xfs_ail          *ailp = qfs->qql_item.li_ailp;
399
400         /*
401          * Delete the qoff-start logitem from the AIL.
402          * xfs_trans_ail_delete() drops the AIL lock.
403          */
404         spin_lock(&ailp->ail_lock);
405         xfs_trans_ail_delete(ailp, &qfs->qql_item, SHUTDOWN_LOG_IO_ERROR);
406
407         kmem_free(qfs->qql_item.li_lv_shadow);
408         kmem_free(lip->li_lv_shadow);
409         kmem_free(qfs);
410         kmem_free(qfe);
411         return (xfs_lsn_t)-1;
412 }
413
414 /*
415  * XXX rcc - don't know quite what to do with this.  I think we can
416  * just ignore it.  The only time that isn't the case is if we allow
417  * the client to somehow see that quotas have been turned off in which
418  * we can't allow that to get back until the quotaoff hits the disk.
419  * So how would that happen?  Also, do we need different routines for
420  * quotaoff start and quotaoff end?  I suspect the answer is yes but
421  * to be sure, I need to look at the recovery code and see how quota off
422  * recovery is handled (do we roll forward or back or do something else).
423  * If we roll forwards or backwards, then we need two separate routines,
424  * one that does nothing and one that stamps in the lsn that matters
425  * (truly makes the quotaoff irrevocable).  If we do something else,
426  * then maybe we don't need two.
427  */
428 STATIC void
429 xfs_qm_qoff_logitem_committing(
430         struct xfs_log_item     *lip,
431         xfs_lsn_t               commit_lsn)
432 {
433 }
434
435 static const struct xfs_item_ops xfs_qm_qoffend_logitem_ops = {
436         .iop_size       = xfs_qm_qoff_logitem_size,
437         .iop_format     = xfs_qm_qoff_logitem_format,
438         .iop_pin        = xfs_qm_qoff_logitem_pin,
439         .iop_unpin      = xfs_qm_qoff_logitem_unpin,
440         .iop_unlock     = xfs_qm_qoff_logitem_unlock,
441         .iop_committed  = xfs_qm_qoffend_logitem_committed,
442         .iop_push       = xfs_qm_qoff_logitem_push,
443         .iop_committing = xfs_qm_qoff_logitem_committing
444 };
445
446 /*
447  * This is the ops vector shared by all quotaoff-start log items.
448  */
449 static const struct xfs_item_ops xfs_qm_qoff_logitem_ops = {
450         .iop_size       = xfs_qm_qoff_logitem_size,
451         .iop_format     = xfs_qm_qoff_logitem_format,
452         .iop_pin        = xfs_qm_qoff_logitem_pin,
453         .iop_unpin      = xfs_qm_qoff_logitem_unpin,
454         .iop_unlock     = xfs_qm_qoff_logitem_unlock,
455         .iop_committed  = xfs_qm_qoff_logitem_committed,
456         .iop_push       = xfs_qm_qoff_logitem_push,
457         .iop_committing = xfs_qm_qoff_logitem_committing
458 };
459
460 /*
461  * Allocate and initialize an quotaoff item of the correct quota type(s).
462  */
463 struct xfs_qoff_logitem *
464 xfs_qm_qoff_logitem_init(
465         struct xfs_mount        *mp,
466         struct xfs_qoff_logitem *start,
467         uint                    flags)
468 {
469         struct xfs_qoff_logitem *qf;
470
471         qf = kmem_zalloc(sizeof(struct xfs_qoff_logitem), KM_SLEEP);
472
473         xfs_log_item_init(mp, &qf->qql_item, XFS_LI_QUOTAOFF, start ?
474                         &xfs_qm_qoffend_logitem_ops : &xfs_qm_qoff_logitem_ops);
475         qf->qql_item.li_mountp = mp;
476         qf->qql_start_lip = start;
477         qf->qql_flags = flags;
478         return qf;
479 }