quota: fix possible infinite loop in quota code
[deliverable/linux.git] / fs / gfs2 / glops.c
1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/gfs2_ondisk.h>
15 #include <linux/lm_interface.h>
16 #include <linux/bio.h>
17
18 #include "gfs2.h"
19 #include "incore.h"
20 #include "bmap.h"
21 #include "glock.h"
22 #include "glops.h"
23 #include "inode.h"
24 #include "log.h"
25 #include "meta_io.h"
26 #include "recovery.h"
27 #include "rgrp.h"
28 #include "util.h"
29 #include "trans.h"
30
31 /**
32 * ail_empty_gl - remove all buffers for a given lock from the AIL
33 * @gl: the glock
34 *
35 * None of the buffers should be dirty, locked, or pinned.
36 */
37
38 static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
39 {
40 struct gfs2_sbd *sdp = gl->gl_sbd;
41 unsigned int blocks;
42 struct list_head *head = &gl->gl_ail_list;
43 struct gfs2_bufdata *bd;
44 struct buffer_head *bh;
45 int error;
46
47 blocks = atomic_read(&gl->gl_ail_count);
48 if (!blocks)
49 return;
50
51 error = gfs2_trans_begin(sdp, 0, blocks);
52 if (gfs2_assert_withdraw(sdp, !error))
53 return;
54
55 gfs2_log_lock(sdp);
56 while (!list_empty(head)) {
57 bd = list_entry(head->next, struct gfs2_bufdata,
58 bd_ail_gl_list);
59 bh = bd->bd_bh;
60 gfs2_remove_from_ail(bd);
61 bd->bd_bh = NULL;
62 bh->b_private = NULL;
63 bd->bd_blkno = bh->b_blocknr;
64 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
65 gfs2_trans_add_revoke(sdp, bd);
66 }
67 gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
68 gfs2_log_unlock(sdp);
69
70 gfs2_trans_end(sdp);
71 gfs2_log_flush(sdp, NULL);
72 }
73
74 /**
75 * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
76 * @gl: the glock
77 *
78 */
79
80 static void gfs2_pte_inval(struct gfs2_glock *gl)
81 {
82 struct gfs2_inode *ip;
83 struct inode *inode;
84
85 ip = gl->gl_object;
86 inode = &ip->i_inode;
87 if (!ip || !S_ISREG(inode->i_mode))
88 return;
89
90 unmap_shared_mapping_range(inode->i_mapping, 0, 0);
91 if (test_bit(GIF_SW_PAGED, &ip->i_flags))
92 set_bit(GLF_DIRTY, &gl->gl_flags);
93
94 }
95
96 /**
97 * meta_go_sync - sync out the metadata for this glock
98 * @gl: the glock
99 *
100 * Called when demoting or unlocking an EX glock. We must flush
101 * to disk all dirty buffers/pages relating to this glock, and must not
102 * not return to caller to demote/unlock the glock until I/O is complete.
103 */
104
105 static void meta_go_sync(struct gfs2_glock *gl)
106 {
107 if (gl->gl_state != LM_ST_EXCLUSIVE)
108 return;
109
110 if (test_and_clear_bit(GLF_DIRTY, &gl->gl_flags)) {
111 gfs2_log_flush(gl->gl_sbd, gl);
112 gfs2_meta_sync(gl);
113 gfs2_ail_empty_gl(gl);
114 }
115 }
116
117 /**
118 * meta_go_inval - invalidate the metadata for this glock
119 * @gl: the glock
120 * @flags:
121 *
122 */
123
124 static void meta_go_inval(struct gfs2_glock *gl, int flags)
125 {
126 if (!(flags & DIO_METADATA))
127 return;
128
129 gfs2_meta_inval(gl);
130 if (gl->gl_object == GFS2_I(gl->gl_sbd->sd_rindex))
131 gl->gl_sbd->sd_rindex_uptodate = 0;
132 else if (gl->gl_ops == &gfs2_rgrp_glops && gl->gl_object) {
133 struct gfs2_rgrpd *rgd = (struct gfs2_rgrpd *)gl->gl_object;
134
135 rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
136 }
137 }
138
139 /**
140 * inode_go_sync - Sync the dirty data and/or metadata for an inode glock
141 * @gl: the glock protecting the inode
142 *
143 */
144
145 static void inode_go_sync(struct gfs2_glock *gl)
146 {
147 struct gfs2_inode *ip = gl->gl_object;
148 struct address_space *metamapping = gl->gl_aspace->i_mapping;
149 int error;
150
151 if (gl->gl_state != LM_ST_UNLOCKED)
152 gfs2_pte_inval(gl);
153 if (gl->gl_state != LM_ST_EXCLUSIVE)
154 return;
155
156 if (ip && !S_ISREG(ip->i_inode.i_mode))
157 ip = NULL;
158
159 if (test_bit(GLF_DIRTY, &gl->gl_flags)) {
160 gfs2_log_flush(gl->gl_sbd, gl);
161 filemap_fdatawrite(metamapping);
162 if (ip) {
163 struct address_space *mapping = ip->i_inode.i_mapping;
164 filemap_fdatawrite(mapping);
165 error = filemap_fdatawait(mapping);
166 mapping_set_error(mapping, error);
167 }
168 error = filemap_fdatawait(metamapping);
169 mapping_set_error(metamapping, error);
170 clear_bit(GLF_DIRTY, &gl->gl_flags);
171 gfs2_ail_empty_gl(gl);
172 }
173 }
174
175 /**
176 * inode_go_inval - prepare a inode glock to be released
177 * @gl: the glock
178 * @flags:
179 *
180 */
181
182 static void inode_go_inval(struct gfs2_glock *gl, int flags)
183 {
184 struct gfs2_inode *ip = gl->gl_object;
185 int meta = (flags & DIO_METADATA);
186
187 if (meta) {
188 gfs2_meta_inval(gl);
189 if (ip)
190 set_bit(GIF_INVALID, &ip->i_flags);
191 }
192
193 if (ip && S_ISREG(ip->i_inode.i_mode))
194 truncate_inode_pages(ip->i_inode.i_mapping, 0);
195 }
196
197 /**
198 * inode_go_demote_ok - Check to see if it's ok to unlock an inode glock
199 * @gl: the glock
200 *
201 * Returns: 1 if it's ok
202 */
203
204 static int inode_go_demote_ok(struct gfs2_glock *gl)
205 {
206 struct gfs2_sbd *sdp = gl->gl_sbd;
207 int demote = 0;
208
209 if (!gl->gl_object && !gl->gl_aspace->i_mapping->nrpages)
210 demote = 1;
211 else if (!sdp->sd_args.ar_localcaching &&
212 time_after_eq(jiffies, gl->gl_stamp +
213 gfs2_tune_get(sdp, gt_demote_secs) * HZ))
214 demote = 1;
215
216 return demote;
217 }
218
219 /**
220 * inode_go_lock - operation done after an inode lock is locked by a process
221 * @gl: the glock
222 * @flags:
223 *
224 * Returns: errno
225 */
226
227 static int inode_go_lock(struct gfs2_holder *gh)
228 {
229 struct gfs2_glock *gl = gh->gh_gl;
230 struct gfs2_inode *ip = gl->gl_object;
231 int error = 0;
232
233 if (!ip || (gh->gh_flags & GL_SKIP))
234 return 0;
235
236 if (test_bit(GIF_INVALID, &ip->i_flags)) {
237 error = gfs2_inode_refresh(ip);
238 if (error)
239 return error;
240 }
241
242 if ((ip->i_di.di_flags & GFS2_DIF_TRUNC_IN_PROG) &&
243 (gl->gl_state == LM_ST_EXCLUSIVE) &&
244 (gh->gh_state == LM_ST_EXCLUSIVE))
245 error = gfs2_truncatei_resume(ip);
246
247 return error;
248 }
249
250 /**
251 * inode_go_dump - print information about an inode
252 * @seq: The iterator
253 * @ip: the inode
254 *
255 * Returns: 0 on success, -ENOBUFS when we run out of space
256 */
257
258 static int inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
259 {
260 const struct gfs2_inode *ip = gl->gl_object;
261 if (ip == NULL)
262 return 0;
263 gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%08lx\n",
264 (unsigned long long)ip->i_no_formal_ino,
265 (unsigned long long)ip->i_no_addr,
266 IF2DT(ip->i_inode.i_mode), ip->i_flags);
267 return 0;
268 }
269
270 /**
271 * rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
272 * @gl: the glock
273 *
274 * Returns: 1 if it's ok
275 */
276
277 static int rgrp_go_demote_ok(struct gfs2_glock *gl)
278 {
279 return !gl->gl_aspace->i_mapping->nrpages;
280 }
281
282 /**
283 * rgrp_go_lock - operation done after an rgrp lock is locked by
284 * a first holder on this node.
285 * @gl: the glock
286 * @flags:
287 *
288 * Returns: errno
289 */
290
291 static int rgrp_go_lock(struct gfs2_holder *gh)
292 {
293 return gfs2_rgrp_bh_get(gh->gh_gl->gl_object);
294 }
295
296 /**
297 * rgrp_go_unlock - operation done before an rgrp lock is unlocked by
298 * a last holder on this node.
299 * @gl: the glock
300 * @flags:
301 *
302 */
303
304 static void rgrp_go_unlock(struct gfs2_holder *gh)
305 {
306 gfs2_rgrp_bh_put(gh->gh_gl->gl_object);
307 }
308
309 /**
310 * rgrp_go_dump - print out an rgrp
311 * @seq: The iterator
312 * @gl: The glock in question
313 *
314 */
315
316 static int rgrp_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
317 {
318 const struct gfs2_rgrpd *rgd = gl->gl_object;
319 if (rgd == NULL)
320 return 0;
321 gfs2_print_dbg(seq, " R: n:%llu\n", (unsigned long long)rgd->rd_addr);
322 return 0;
323 }
324
325 /**
326 * trans_go_sync - promote/demote the transaction glock
327 * @gl: the glock
328 * @state: the requested state
329 * @flags:
330 *
331 */
332
333 static void trans_go_sync(struct gfs2_glock *gl)
334 {
335 struct gfs2_sbd *sdp = gl->gl_sbd;
336
337 if (gl->gl_state != LM_ST_UNLOCKED &&
338 test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
339 gfs2_meta_syncfs(sdp);
340 gfs2_log_shutdown(sdp);
341 }
342 }
343
344 /**
345 * trans_go_xmote_bh - After promoting/demoting the transaction glock
346 * @gl: the glock
347 *
348 */
349
350 static int trans_go_xmote_bh(struct gfs2_glock *gl, struct gfs2_holder *gh)
351 {
352 struct gfs2_sbd *sdp = gl->gl_sbd;
353 struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
354 struct gfs2_glock *j_gl = ip->i_gl;
355 struct gfs2_log_header_host head;
356 int error;
357
358 if (test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
359 j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
360
361 error = gfs2_find_jhead(sdp->sd_jdesc, &head);
362 if (error)
363 gfs2_consist(sdp);
364 if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
365 gfs2_consist(sdp);
366
367 /* Initialize some head of the log stuff */
368 if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
369 sdp->sd_log_sequence = head.lh_sequence + 1;
370 gfs2_log_pointers_init(sdp, head.lh_blkno);
371 }
372 }
373 return 0;
374 }
375
376 /**
377 * quota_go_demote_ok - Check to see if it's ok to unlock a quota glock
378 * @gl: the glock
379 *
380 * Returns: 1 if it's ok
381 */
382
383 static int quota_go_demote_ok(struct gfs2_glock *gl)
384 {
385 return !atomic_read(&gl->gl_lvb_count);
386 }
387
388 const struct gfs2_glock_operations gfs2_meta_glops = {
389 .go_xmote_th = meta_go_sync,
390 .go_type = LM_TYPE_META,
391 };
392
393 const struct gfs2_glock_operations gfs2_inode_glops = {
394 .go_xmote_th = inode_go_sync,
395 .go_inval = inode_go_inval,
396 .go_demote_ok = inode_go_demote_ok,
397 .go_lock = inode_go_lock,
398 .go_dump = inode_go_dump,
399 .go_type = LM_TYPE_INODE,
400 .go_min_hold_time = HZ / 5,
401 };
402
403 const struct gfs2_glock_operations gfs2_rgrp_glops = {
404 .go_xmote_th = meta_go_sync,
405 .go_inval = meta_go_inval,
406 .go_demote_ok = rgrp_go_demote_ok,
407 .go_lock = rgrp_go_lock,
408 .go_unlock = rgrp_go_unlock,
409 .go_dump = rgrp_go_dump,
410 .go_type = LM_TYPE_RGRP,
411 .go_min_hold_time = HZ / 5,
412 };
413
414 const struct gfs2_glock_operations gfs2_trans_glops = {
415 .go_xmote_th = trans_go_sync,
416 .go_xmote_bh = trans_go_xmote_bh,
417 .go_type = LM_TYPE_NONDISK,
418 };
419
420 const struct gfs2_glock_operations gfs2_iopen_glops = {
421 .go_type = LM_TYPE_IOPEN,
422 };
423
424 const struct gfs2_glock_operations gfs2_flock_glops = {
425 .go_type = LM_TYPE_FLOCK,
426 };
427
428 const struct gfs2_glock_operations gfs2_nondisk_glops = {
429 .go_type = LM_TYPE_NONDISK,
430 };
431
432 const struct gfs2_glock_operations gfs2_quota_glops = {
433 .go_demote_ok = quota_go_demote_ok,
434 .go_type = LM_TYPE_QUOTA,
435 };
436
437 const struct gfs2_glock_operations gfs2_journal_glops = {
438 .go_type = LM_TYPE_JOURNAL,
439 };
440
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