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2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771 
 kernel/fs/quota/dquot.c
....@@ -9,7 +9,7 @@
99  * on the Melbourne quota system as used on BSD derived systems. The internal
1010  * implementation is based on one of the several variants of the LINUX
1111  * inode-subsystem with added complexity of the diskquota system.
12
- * 
12
+ *
1313  * Author:	Marco van Wieringen <mvw@planets.elm.net>
1414  *
1515  * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
....@@ -51,7 +51,7 @@
5151  *		Added journalled quota support, fix lock inversion problems
5252  *		Jan Kara, <jack@suse.cz>, 2003,2004
5353  *
54
- * (C) Copyright 1994 - 1997 Marco van Wieringen 
54
+ * (C) Copyright 1994 - 1997 Marco van Wieringen
5555  */
5656 
5757 #include <linux/errno.h>
....@@ -78,6 +78,8 @@
7878 #include <linux/namei.h>
7979 #include <linux/capability.h>
8080 #include <linux/quotaops.h>
81
+#include <linux/blkdev.h>
82
+#include <linux/sched/mm.h>
8183 #include "../internal.h" /* ugh */
8284 
8385 #include <linux/uaccess.h>
....@@ -197,7 +199,7 @@
197199 		int qm;
198200 
199201 		spin_unlock(&dq_list_lock);
200
-		
202
+
201203 		for (qm = 0; module_names[qm].qm_fmt_id &&
202204 			     module_names[qm].qm_fmt_id != id; qm++)
203205 			;
....@@ -223,18 +225,32 @@
223225 
224226 /*
225227  * Dquot List Management:
226
- * The quota code uses three lists for dquot management: the inuse_list,
227
- * free_dquots, and dquot_hash[] array. A single dquot structure may be
228
- * on all three lists, depending on its current state.
228
+ * The quota code uses five lists for dquot management: the inuse_list,
229
+ * releasing_dquots, free_dquots, dqi_dirty_list, and dquot_hash[] array.
230
+ * A single dquot structure may be on some of those lists, depending on
231
+ * its current state.
229232  *
230233  * All dquots are placed to the end of inuse_list when first created, and this
231234  * list is used for invalidate operation, which must look at every dquot.
235
+ *
236
+ * When the last reference of a dquot will be dropped, the dquot will be
237
+ * added to releasing_dquots. We'd then queue work item which would call
238
+ * synchronize_srcu() and after that perform the final cleanup of all the
239
+ * dquots on the list. Both releasing_dquots and free_dquots use the
240
+ * dq_free list_head in the dquot struct. When a dquot is removed from
241
+ * releasing_dquots, a reference count is always subtracted, and if
242
+ * dq_count == 0 at that point, the dquot will be added to the free_dquots.
232243  *
233244  * Unused dquots (dq_count == 0) are added to the free_dquots list when freed,
234245  * and this list is searched whenever we need an available dquot.  Dquots are
235246  * removed from the list as soon as they are used again, and
236247  * dqstats.free_dquots gives the number of dquots on the list. When
237248  * dquot is invalidated it's completely released from memory.
249
+ *
250
+ * Dirty dquots are added to the dqi_dirty_list of quota_info when mark
251
+ * dirtied, and this list is searched when writing dirty dquots back to
252
+ * quota file. Note that some filesystems do dirty dquot tracking on their
253
+ * own (e.g. in a journal) and thus don't use dqi_dirty_list.
238254  *
239255  * Dquots with a specific identity (device, type and id) are placed on
240256  * one of the dquot_hash[] hash chains. The provides an efficient search
....@@ -243,6 +259,7 @@
243259 
244260 static LIST_HEAD(inuse_list);
245261 static LIST_HEAD(free_dquots);
262
+static LIST_HEAD(releasing_dquots);
246263 static unsigned int dq_hash_bits, dq_hash_mask;
247264 static struct hlist_head *dquot_hash;
248265 
....@@ -252,6 +269,9 @@
252269 static qsize_t inode_get_rsv_space(struct inode *inode);
253270 static qsize_t __inode_get_rsv_space(struct inode *inode);
254271 static int __dquot_initialize(struct inode *inode, int type);
272
+
273
+static void quota_release_workfn(struct work_struct *work);
274
+static DECLARE_DELAYED_WORK(quota_release_work, quota_release_workfn);
255275 
256276 static inline unsigned int
257277 hashfn(const struct super_block *sb, struct kqid qid)
....@@ -300,12 +320,18 @@
300320 	dqstats_inc(DQST_FREE_DQUOTS);
301321 }
302322 
323
+static inline void put_releasing_dquots(struct dquot *dquot)
324
+{
325
+	list_add_tail(&dquot->dq_free, &releasing_dquots);
326
+}
327
+
303328 static inline void remove_free_dquot(struct dquot *dquot)
304329 {
305330 	if (list_empty(&dquot->dq_free))
306331 		return;
307332 	list_del_init(&dquot->dq_free);
308
-	dqstats_dec(DQST_FREE_DQUOTS);
333
+	if (!atomic_read(&dquot->dq_count))
334
+		dqstats_dec(DQST_FREE_DQUOTS);
309335 }
310336 
311337 static inline void put_inuse(struct dquot *dquot)
....@@ -331,6 +357,11 @@
331357 	mutex_unlock(&dquot->dq_lock);
332358 }
333359 
360
+static inline int dquot_active(struct dquot *dquot)
361
+{
362
+	return test_bit(DQ_ACTIVE_B, &dquot->dq_flags);
363
+}
364
+
334365 static inline int dquot_dirty(struct dquot *dquot)
335366 {
336367 	return test_bit(DQ_MOD_B, &dquot->dq_flags);
....@@ -346,14 +377,14 @@
346377 {
347378 	int ret = 1;
348379 
349
-	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
380
+	if (!dquot_active(dquot))
350381 		return 0;
351382 
352383 	if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
353384 		return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
354385 
355386 	/* If quota is dirty already, we don't have to acquire dq_list_lock */
356
-	if (test_bit(DQ_MOD_B, &dquot->dq_flags))
387
+	if (dquot_dirty(dquot))
357388 		return 1;
358389 
359390 	spin_lock(&dq_list_lock);
....@@ -421,18 +452,21 @@
421452 int dquot_acquire(struct dquot *dquot)
422453 {
423454 	int ret = 0, ret2 = 0;
455
+	unsigned int memalloc;
424456 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
425457 
426458 	mutex_lock(&dquot->dq_lock);
427
-	if (!test_bit(DQ_READ_B, &dquot->dq_flags))
459
+	memalloc = memalloc_nofs_save();
460
+	if (!test_bit(DQ_READ_B, &dquot->dq_flags)) {
428461 		ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
429
-	if (ret < 0)
430
-		goto out_iolock;
462
+		if (ret < 0)
463
+			goto out_iolock;
464
+	}
431465 	/* Make sure flags update is visible after dquot has been filled */
432466 	smp_mb__before_atomic();
433467 	set_bit(DQ_READ_B, &dquot->dq_flags);
434468 	/* Instantiate dquot if needed */
435
-	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
469
+	if (!dquot_active(dquot) && !dquot->dq_off) {
436470 		ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
437471 		/* Write the info if needed */
438472 		if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
....@@ -453,6 +487,7 @@
453487 	smp_mb__before_atomic();
454488 	set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
455489 out_iolock:
490
+	memalloc_nofs_restore(memalloc);
456491 	mutex_unlock(&dquot->dq_lock);
457492 	return ret;
458493 }
....@@ -464,18 +499,21 @@
464499 int dquot_commit(struct dquot *dquot)
465500 {
466501 	int ret = 0;
502
+	unsigned int memalloc;
467503 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
468504 
469505 	mutex_lock(&dquot->dq_lock);
506
+	memalloc = memalloc_nofs_save();
470507 	if (!clear_dquot_dirty(dquot))
471508 		goto out_lock;
472509 	/* Inactive dquot can be only if there was error during read/init
473510 	 * => we have better not writing it */
474
-	if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
511
+	if (dquot_active(dquot))
475512 		ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
476513 	else
477514 		ret = -EIO;
478515 out_lock:
516
+	memalloc_nofs_restore(memalloc);
479517 	mutex_unlock(&dquot->dq_lock);
480518 	return ret;
481519 }
....@@ -487,9 +525,11 @@
487525 int dquot_release(struct dquot *dquot)
488526 {
489527 	int ret = 0, ret2 = 0;
528
+	unsigned int memalloc;
490529 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
491530 
492531 	mutex_lock(&dquot->dq_lock);
532
+	memalloc = memalloc_nofs_save();
493533 	/* Check whether we are not racing with some other dqget() */
494534 	if (dquot_is_busy(dquot))
495535 		goto out_dqlock;
....@@ -505,6 +545,7 @@
505545 	}
506546 	clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
507547 out_dqlock:
548
+	memalloc_nofs_restore(memalloc);
508549 	mutex_unlock(&dquot->dq_lock);
509550 	return ret;
510551 }
....@@ -532,6 +573,8 @@
532573 	struct dquot *dquot, *tmp;
533574 
534575 restart:
576
+	flush_delayed_work(&quota_release_work);
577
+
535578 	spin_lock(&dq_list_lock);
536579 	list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
537580 		if (dquot->dq_sb != sb)
....@@ -540,7 +583,13 @@
540583 			continue;
541584 		/* Wait for dquot users */
542585 		if (atomic_read(&dquot->dq_count)) {
543
-			dqgrab(dquot);
586
+			/* dquot in releasing_dquots, flush and retry */
587
+			if (!list_empty(&dquot->dq_free)) {
588
+				spin_unlock(&dq_list_lock);
589
+				goto restart;
590
+			}
591
+
592
+			atomic_inc(&dquot->dq_count);
544593 			spin_unlock(&dq_list_lock);
545594 			/*
546595 			 * Once dqput() wakes us up, we know it's time to free
....@@ -582,14 +631,13 @@
582631 
583632 	spin_lock(&dq_list_lock);
584633 	list_for_each_entry(dquot, &inuse_list, dq_inuse) {
585
-		if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
634
+		if (!dquot_active(dquot))
586635 			continue;
587636 		if (dquot->dq_sb != sb)
588637 			continue;
589638 		/* Now we have active dquot so we can just increase use count */
590639 		atomic_inc(&dquot->dq_count);
591640 		spin_unlock(&dq_list_lock);
592
-		dqstats_inc(DQST_LOOKUPS);
593641 		dqput(old_dquot);
594642 		old_dquot = dquot;
595643 		/*
....@@ -598,7 +646,7 @@
598646 		 * outstanding call and recheck the DQ_ACTIVE_B after that.
599647 		 */
600648 		wait_on_dquot(dquot);
601
-		if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
649
+		if (dquot_active(dquot)) {
602650 			ret = fn(dquot, priv);
603651 			if (ret < 0)
604652 				goto out;
....@@ -613,6 +661,18 @@
613661 	return ret;
614662 }
615663 EXPORT_SYMBOL(dquot_scan_active);
664
+
665
+static inline int dquot_write_dquot(struct dquot *dquot)
666
+{
667
+	int ret = dquot->dq_sb->dq_op->write_dquot(dquot);
668
+	if (ret < 0) {
669
+		quota_error(dquot->dq_sb, "Can't write quota structure "
670
+			    "(error %d). Quota may get out of sync!", ret);
671
+		/* Clear dirty bit anyway to avoid infinite loop. */
672
+		clear_dquot_dirty(dquot);
673
+	}
674
+	return ret;
675
+}
616676 
617677 /* Write all dquot structures to quota files */
618678 int dquot_writeback_dquots(struct super_block *sb, int type)
....@@ -637,24 +697,16 @@
637697 			dquot = list_first_entry(&dirty, struct dquot,
638698 						 dq_dirty);
639699 
640
-			WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));
700
+			WARN_ON(!dquot_active(dquot));
641701 
642702 			/* Now we have active dquot from which someone is
643703  			 * holding reference so we can safely just increase
644704 			 * use count */
645705 			dqgrab(dquot);
646706 			spin_unlock(&dq_list_lock);
647
-			dqstats_inc(DQST_LOOKUPS);
648
-			err = sb->dq_op->write_dquot(dquot);
649
-			if (err) {
650
-				/*
651
-				 * Clear dirty bit anyway to avoid infinite
652
-				 * loop here.
653
-				 */
654
-				clear_dquot_dirty(dquot);
655
-				if (!ret)
656
-					ret = err;
657
-			}
707
+			err = dquot_write_dquot(dquot);
708
+			if (err && !ret)
709
+				ret = err;
658710 			dqput(dquot);
659711 			spin_lock(&dq_list_lock);
660712 		}
....@@ -748,12 +800,53 @@
748800 };
749801 
750802 /*
803
+ * Safely release dquot and put reference to dquot.
804
+ */
805
+static void quota_release_workfn(struct work_struct *work)
806
+{
807
+	struct dquot *dquot;
808
+	struct list_head rls_head;
809
+
810
+	spin_lock(&dq_list_lock);
811
+	/* Exchange the list head to avoid livelock. */
812
+	list_replace_init(&releasing_dquots, &rls_head);
813
+	spin_unlock(&dq_list_lock);
814
+
815
+restart:
816
+	synchronize_srcu(&dquot_srcu);
817
+	spin_lock(&dq_list_lock);
818
+	while (!list_empty(&rls_head)) {
819
+		dquot = list_first_entry(&rls_head, struct dquot, dq_free);
820
+		/* Dquot got used again? */
821
+		if (atomic_read(&dquot->dq_count) > 1) {
822
+			remove_free_dquot(dquot);
823
+			atomic_dec(&dquot->dq_count);
824
+			continue;
825
+		}
826
+		if (dquot_dirty(dquot)) {
827
+			spin_unlock(&dq_list_lock);
828
+			/* Commit dquot before releasing */
829
+			dquot_write_dquot(dquot);
830
+			goto restart;
831
+		}
832
+		if (dquot_active(dquot)) {
833
+			spin_unlock(&dq_list_lock);
834
+			dquot->dq_sb->dq_op->release_dquot(dquot);
835
+			goto restart;
836
+		}
837
+		/* Dquot is inactive and clean, now move it to free list */
838
+		remove_free_dquot(dquot);
839
+		atomic_dec(&dquot->dq_count);
840
+		put_dquot_last(dquot);
841
+	}
842
+	spin_unlock(&dq_list_lock);
843
+}
844
+
845
+/*
751846  * Put reference to dquot
752847  */
753848 void dqput(struct dquot *dquot)
754849 {
755
-	int ret;
756
-
757850 	if (!dquot)
758851 		return;
759852 #ifdef CONFIG_QUOTA_DEBUG
....@@ -765,7 +858,7 @@
765858 	}
766859 #endif
767860 	dqstats_inc(DQST_DROPS);
768
-we_slept:
861
+
769862 	spin_lock(&dq_list_lock);
770863 	if (atomic_read(&dquot->dq_count) > 1) {
771864 		/* We have more than one user... nothing to do */
....@@ -777,35 +870,15 @@
777870 		spin_unlock(&dq_list_lock);
778871 		return;
779872 	}
873
+
780874 	/* Need to release dquot? */
781
-	if (dquot_dirty(dquot)) {
782
-		spin_unlock(&dq_list_lock);
783
-		/* Commit dquot before releasing */
784
-		ret = dquot->dq_sb->dq_op->write_dquot(dquot);
785
-		if (ret < 0) {
786
-			quota_error(dquot->dq_sb, "Can't write quota structure"
787
-				    " (error %d). Quota may get out of sync!",
788
-				    ret);
789
-			/*
790
-			 * We clear dirty bit anyway, so that we avoid
791
-			 * infinite loop here
792
-			 */
793
-			clear_dquot_dirty(dquot);
794
-		}
795
-		goto we_slept;
796
-	}
797
-	if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
798
-		spin_unlock(&dq_list_lock);
799
-		dquot->dq_sb->dq_op->release_dquot(dquot);
800
-		goto we_slept;
801
-	}
802
-	atomic_dec(&dquot->dq_count);
803875 #ifdef CONFIG_QUOTA_DEBUG
804876 	/* sanity check */
805877 	BUG_ON(!list_empty(&dquot->dq_free));
806878 #endif
807
-	put_dquot_last(dquot);
879
+	put_releasing_dquots(dquot);
808880 	spin_unlock(&dq_list_lock);
881
+	queue_delayed_work(system_unbound_wq, &quota_release_work, 1);
809882 }
810883 EXPORT_SYMBOL(dqput);
811884 
....@@ -895,7 +968,7 @@
895968 	 * already finished or it will be canceled due to dq_count > 1 test */
896969 	wait_on_dquot(dquot);
897970 	/* Read the dquot / allocate space in quota file */
898
-	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
971
+	if (!dquot_active(dquot)) {
899972 		int err;
900973 
901974 		err = sb->dq_op->acquire_dquot(dquot);
....@@ -1056,7 +1129,9 @@
10561129 		struct list_head *tofree_head)
10571130 {
10581131 	struct inode *inode;
1132
+#ifdef CONFIG_QUOTA_DEBUG
10591133 	int reserved = 0;
1134
+#endif
10601135 
10611136 	spin_lock(&sb->s_inode_list_lock);
10621137 	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
....@@ -1068,8 +1143,10 @@
10681143 		 */
10691144 		spin_lock(&dq_data_lock);
10701145 		if (!IS_NOQUOTA(inode)) {
1146
+#ifdef CONFIG_QUOTA_DEBUG
10711147 			if (unlikely(inode_get_rsv_space(inode) > 0))
10721148 				reserved = 1;
1149
+#endif
10731150 			remove_inode_dquot_ref(inode, type, tofree_head);
10741151 		}
10751152 		spin_unlock(&dq_data_lock);
....@@ -1408,7 +1485,7 @@
14081485 	return QUOTA_NL_NOWARN;
14091486 }
14101487 
1411
-static int dquot_active(const struct inode *inode)
1488
+static int inode_quota_active(const struct inode *inode)
14121489 {
14131490 	struct super_block *sb = inode->i_sb;
14141491 
....@@ -1431,7 +1508,7 @@
14311508 	qsize_t rsv;
14321509 	int ret = 0;
14331510 
1434
-	if (!dquot_active(inode))
1511
+	if (!inode_quota_active(inode))
14351512 		return 0;
14361513 
14371514 	dquots = i_dquot(inode);
....@@ -1539,7 +1616,7 @@
15391616 	struct dquot **dquots;
15401617 	int i;
15411618 
1542
-	if (!dquot_active(inode))
1619
+	if (!inode_quota_active(inode))
15431620 		return false;
15441621 
15451622 	dquots = i_dquot(inode);
....@@ -1650,7 +1727,7 @@
16501727 	int reserve = flags & DQUOT_SPACE_RESERVE;
16511728 	struct dquot **dquots;
16521729 
1653
-	if (!dquot_active(inode)) {
1730
+	if (!inode_quota_active(inode)) {
16541731 		if (reserve) {
16551732 			spin_lock(&inode->i_lock);
16561733 			*inode_reserved_space(inode) += number;
....@@ -1670,7 +1747,7 @@
16701747 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
16711748 		if (!dquots[cnt])
16721749 			continue;
1673
-		if (flags & DQUOT_SPACE_RESERVE) {
1750
+		if (reserve) {
16741751 			ret = dquot_add_space(dquots[cnt], 0, number, flags,
16751752 					      &warn[cnt]);
16761753 		} else {
....@@ -1683,13 +1760,11 @@
16831760 				if (!dquots[cnt])
16841761 					continue;
16851762 				spin_lock(&dquots[cnt]->dq_dqb_lock);
1686
-				if (flags & DQUOT_SPACE_RESERVE) {
1687
-					dquots[cnt]->dq_dqb.dqb_rsvspace -=
1688
-									number;
1689
-				} else {
1690
-					dquots[cnt]->dq_dqb.dqb_curspace -=
1691
-									number;
1692
-				}
1763
+				if (reserve)
1764
+					dquot_free_reserved_space(dquots[cnt],
1765
+								  number);
1766
+				else
1767
+					dquot_decr_space(dquots[cnt], number);
16931768 				spin_unlock(&dquots[cnt]->dq_dqb_lock);
16941769 			}
16951770 			spin_unlock(&inode->i_lock);
....@@ -1722,7 +1797,7 @@
17221797 	struct dquot_warn warn[MAXQUOTAS];
17231798 	struct dquot * const *dquots;
17241799 
1725
-	if (!dquot_active(inode))
1800
+	if (!inode_quota_active(inode))
17261801 		return 0;
17271802 	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
17281803 		warn[cnt].w_type = QUOTA_NL_NOWARN;
....@@ -1740,7 +1815,7 @@
17401815 					continue;
17411816 				/* Back out changes we already did */
17421817 				spin_lock(&dquots[cnt]->dq_dqb_lock);
1743
-				dquots[cnt]->dq_dqb.dqb_curinodes--;
1818
+				dquot_decr_inodes(dquots[cnt], 1);
17441819 				spin_unlock(&dquots[cnt]->dq_dqb_lock);
17451820 			}
17461821 			goto warn_put_all;
....@@ -1765,7 +1840,7 @@
17651840 	struct dquot **dquots;
17661841 	int cnt, index;
17671842 
1768
-	if (!dquot_active(inode)) {
1843
+	if (!inode_quota_active(inode)) {
17691844 		spin_lock(&inode->i_lock);
17701845 		*inode_reserved_space(inode) -= number;
17711846 		__inode_add_bytes(inode, number);
....@@ -1807,7 +1882,7 @@
18071882 	struct dquot **dquots;
18081883 	int cnt, index;
18091884 
1810
-	if (!dquot_active(inode)) {
1885
+	if (!inode_quota_active(inode)) {
18111886 		spin_lock(&inode->i_lock);
18121887 		*inode_reserved_space(inode) += number;
18131888 		__inode_sub_bytes(inode, number);
....@@ -1851,7 +1926,7 @@
18511926 	struct dquot **dquots;
18521927 	int reserve = flags & DQUOT_SPACE_RESERVE, index;
18531928 
1854
-	if (!dquot_active(inode)) {
1929
+	if (!inode_quota_active(inode)) {
18551930 		if (reserve) {
18561931 			spin_lock(&inode->i_lock);
18571932 			*inode_reserved_space(inode) -= number;
....@@ -1906,7 +1981,7 @@
19061981 	struct dquot * const *dquots;
19071982 	int index;
19081983 
1909
-	if (!dquot_active(inode))
1984
+	if (!inode_quota_active(inode))
19101985 		return;
19111986 
19121987 	dquots = i_dquot(inode);
....@@ -2077,7 +2152,7 @@
20772152 	struct super_block *sb = inode->i_sb;
20782153 	int ret;
20792154 
2080
-	if (!dquot_active(inode))
2155
+	if (!inode_quota_active(inode))
20812156 		return 0;
20822157 
20832158 	if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){
....@@ -2161,14 +2236,29 @@
21612236 }
21622237 EXPORT_SYMBOL(dquot_file_open);
21632238 
2239
+static void vfs_cleanup_quota_inode(struct super_block *sb, int type)
2240
+{
2241
+	struct quota_info *dqopt = sb_dqopt(sb);
2242
+	struct inode *inode = dqopt->files[type];
2243
+
2244
+	if (!inode)
2245
+		return;
2246
+	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2247
+		inode_lock(inode);
2248
+		inode->i_flags &= ~S_NOQUOTA;
2249
+		inode_unlock(inode);
2250
+	}
2251
+	dqopt->files[type] = NULL;
2252
+	iput(inode);
2253
+}
2254
+
21642255 /*
21652256  * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
21662257  */
21672258 int dquot_disable(struct super_block *sb, int type, unsigned int flags)
21682259 {
2169
-	int cnt, ret = 0;
2260
+	int cnt;
21702261 	struct quota_info *dqopt = sb_dqopt(sb);
2171
-	struct inode *toputinode[MAXQUOTAS];
21722262 
21732263 	/* s_umount should be held in exclusive mode */
21742264 	if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
....@@ -2190,7 +2280,6 @@
21902280 		return 0;
21912281 
21922282 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
2193
-		toputinode[cnt] = NULL;
21942283 		if (type != -1 && cnt != type)
21952284 			continue;
21962285 		if (!sb_has_quota_loaded(sb, cnt))
....@@ -2210,8 +2299,7 @@
22102299 				dqopt->flags &=	~dquot_state_flag(
22112300 							DQUOT_SUSPENDED, cnt);
22122301 				spin_unlock(&dq_state_lock);
2213
-				iput(dqopt->files[cnt]);
2214
-				dqopt->files[cnt] = NULL;
2302
+				vfs_cleanup_quota_inode(sb, cnt);
22152303 				continue;
22162304 			}
22172305 			spin_unlock(&dq_state_lock);
....@@ -2233,10 +2321,6 @@
22332321 		if (dqopt->ops[cnt]->free_file_info)
22342322 			dqopt->ops[cnt]->free_file_info(sb, cnt);
22352323 		put_quota_format(dqopt->info[cnt].dqi_format);
2236
-
2237
-		toputinode[cnt] = dqopt->files[cnt];
2238
-		if (!sb_has_quota_loaded(sb, cnt))
2239
-			dqopt->files[cnt] = NULL;
22402324 		dqopt->info[cnt].dqi_flags = 0;
22412325 		dqopt->info[cnt].dqi_igrace = 0;
22422326 		dqopt->info[cnt].dqi_bgrace = 0;
....@@ -2258,32 +2342,22 @@
22582342 	 * must also discard the blockdev buffers so that we see the
22592343 	 * changes done by userspace on the next quotaon() */
22602344 	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2261
-		/* This can happen when suspending quotas on remount-ro... */
2262
-		if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) {
2263
-			inode_lock(toputinode[cnt]);
2264
-			toputinode[cnt]->i_flags &= ~S_NOQUOTA;
2265
-			truncate_inode_pages(&toputinode[cnt]->i_data, 0);
2266
-			inode_unlock(toputinode[cnt]);
2267
-			mark_inode_dirty_sync(toputinode[cnt]);
2345
+		if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) {
2346
+			inode_lock(dqopt->files[cnt]);
2347
+			truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
2348
+			inode_unlock(dqopt->files[cnt]);
22682349 		}
22692350 	if (sb->s_bdev)
22702351 		invalidate_bdev(sb->s_bdev);
22712352 put_inodes:
2353
+	/* We are done when suspending quotas */
2354
+	if (flags & DQUOT_SUSPENDED)
2355
+		return 0;
2356
+
22722357 	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
2273
-		if (toputinode[cnt]) {
2274
-			/* On remount RO, we keep the inode pointer so that we
2275
-			 * can reenable quota on the subsequent remount RW. We
2276
-			 * have to check 'flags' variable and not use sb_has_
2277
-			 * function because another quotaon / quotaoff could
2278
-			 * change global state before we got here. We refuse
2279
-			 * to suspend quotas when there is pending delete on
2280
-			 * the quota file... */
2281
-			if (!(flags & DQUOT_SUSPENDED))
2282
-				iput(toputinode[cnt]);
2283
-			else if (!toputinode[cnt]->i_nlink)
2284
-				ret = -EBUSY;
2285
-		}
2286
-	return ret;
2358
+		if (!sb_has_quota_loaded(sb, cnt))
2359
+			vfs_cleanup_quota_inode(sb, cnt);
2360
+	return 0;
22872361 }
22882362 EXPORT_SYMBOL(dquot_disable);
22892363 
....@@ -2298,28 +2372,54 @@
22982372  *	Turn quotas on on a device
22992373  */
23002374 
2301
-/*
2302
- * Helper function to turn quotas on when we already have the inode of
2303
- * quota file and no quota information is loaded.
2304
- */
2305
-static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
2375
+static int vfs_setup_quota_inode(struct inode *inode, int type)
2376
+{
2377
+	struct super_block *sb = inode->i_sb;
2378
+	struct quota_info *dqopt = sb_dqopt(sb);
2379
+
2380
+	if (is_bad_inode(inode))
2381
+		return -EUCLEAN;
2382
+	if (!S_ISREG(inode->i_mode))
2383
+		return -EACCES;
2384
+	if (IS_RDONLY(inode))
2385
+		return -EROFS;
2386
+	if (sb_has_quota_loaded(sb, type))
2387
+		return -EBUSY;
2388
+
2389
+	dqopt->files[type] = igrab(inode);
2390
+	if (!dqopt->files[type])
2391
+		return -EIO;
2392
+	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2393
+		/* We don't want quota and atime on quota files (deadlocks
2394
+		 * possible) Also nobody should write to the file - we use
2395
+		 * special IO operations which ignore the immutable bit. */
2396
+		inode_lock(inode);
2397
+		inode->i_flags |= S_NOQUOTA;
2398
+		inode_unlock(inode);
2399
+		/*
2400
+		 * When S_NOQUOTA is set, remove dquot references as no more
2401
+		 * references can be added
2402
+		 */
2403
+		__dquot_drop(inode);
2404
+	}
2405
+	return 0;
2406
+}
2407
+
2408
+int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
23062409 	unsigned int flags)
23072410 {
23082411 	struct quota_format_type *fmt = find_quota_format(format_id);
2309
-	struct super_block *sb = inode->i_sb;
23102412 	struct quota_info *dqopt = sb_dqopt(sb);
23112413 	int error;
23122414 
2415
+	/* Just unsuspend quotas? */
2416
+	BUG_ON(flags & DQUOT_SUSPENDED);
2417
+	/* s_umount should be held in exclusive mode */
2418
+	if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2419
+		up_read(&sb->s_umount);
2420
+
23132421 	if (!fmt)
23142422 		return -ESRCH;
2315
-	if (!S_ISREG(inode->i_mode)) {
2316
-		error = -EACCES;
2317
-		goto out_fmt;
2318
-	}
2319
-	if (IS_RDONLY(inode)) {
2320
-		error = -EROFS;
2321
-		goto out_fmt;
2322
-	}
23232423 	if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
23242424 	    (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
23252425 		error = -EINVAL;
....@@ -2351,27 +2451,9 @@
23512451 		invalidate_bdev(sb->s_bdev);
23522452 	}
23532453 
2354
-	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
2355
-		/* We don't want quota and atime on quota files (deadlocks
2356
-		 * possible) Also nobody should write to the file - we use
2357
-		 * special IO operations which ignore the immutable bit. */
2358
-		inode_lock(inode);
2359
-		inode->i_flags |= S_NOQUOTA;
2360
-		inode_unlock(inode);
2361
-		/*
2362
-		 * When S_NOQUOTA is set, remove dquot references as no more
2363
-		 * references can be added
2364
-		 */
2365
-		__dquot_drop(inode);
2366
-	}
2367
-
2368
-	error = -EIO;
2369
-	dqopt->files[type] = igrab(inode);
2370
-	if (!dqopt->files[type])
2371
-		goto out_file_flags;
23722454 	error = -EINVAL;
23732455 	if (!fmt->qf_ops->check_quota_file(sb, type))
2374
-		goto out_file_init;
2456
+		goto out_fmt;
23752457 
23762458 	dqopt->ops[type] = fmt->qf_ops;
23772459 	dqopt->info[type].dqi_format = fmt;
....@@ -2379,7 +2461,7 @@
23792461 	INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
23802462 	error = dqopt->ops[type]->read_file_info(sb, type);
23812463 	if (error < 0)
2382
-		goto out_file_init;
2464
+		goto out_fmt;
23832465 	if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
23842466 		spin_lock(&dq_data_lock);
23852467 		dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
....@@ -2391,27 +2473,40 @@
23912473 
23922474 	error = add_dquot_ref(sb, type);
23932475 	if (error)
2394
-		dquot_disable(sb, type, flags);
2476
+		dquot_disable(sb, type,
2477
+			      DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
23952478 
23962479 	return error;
2397
-out_file_init:
2398
-	dqopt->files[type] = NULL;
2399
-	iput(inode);
2400
-out_file_flags:
2401
-	inode_lock(inode);
2402
-	inode->i_flags &= ~S_NOQUOTA;
2403
-	inode_unlock(inode);
24042480 out_fmt:
24052481 	put_quota_format(fmt);
24062482 
2407
-	return error; 
2483
+	return error;
24082484 }
2485
+EXPORT_SYMBOL(dquot_load_quota_sb);
2486
+
2487
+/*
2488
+ * More powerful function for turning on quotas on given quota inode allowing
2489
+ * setting of individual quota flags
2490
+ */
2491
+int dquot_load_quota_inode(struct inode *inode, int type, int format_id,
2492
+	unsigned int flags)
2493
+{
2494
+	int err;
2495
+
2496
+	err = vfs_setup_quota_inode(inode, type);
2497
+	if (err < 0)
2498
+		return err;
2499
+	err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags);
2500
+	if (err < 0)
2501
+		vfs_cleanup_quota_inode(inode->i_sb, type);
2502
+	return err;
2503
+}
2504
+EXPORT_SYMBOL(dquot_load_quota_inode);
24092505 
24102506 /* Reenable quotas on remount RW */
24112507 int dquot_resume(struct super_block *sb, int type)
24122508 {
24132509 	struct quota_info *dqopt = sb_dqopt(sb);
2414
-	struct inode *inode;
24152510 	int ret = 0, cnt;
24162511 	unsigned int flags;
24172512 
....@@ -2425,8 +2520,6 @@
24252520 		if (!sb_has_quota_suspended(sb, cnt))
24262521 			continue;
24272522 
2428
-		inode = dqopt->files[cnt];
2429
-		dqopt->files[cnt] = NULL;
24302523 		spin_lock(&dq_state_lock);
24312524 		flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
24322525 							DQUOT_LIMITS_ENABLED,
....@@ -2435,9 +2528,10 @@
24352528 		spin_unlock(&dq_state_lock);
24362529 
24372530 		flags = dquot_generic_flag(flags, cnt);
2438
-		ret = vfs_load_quota_inode(inode, cnt,
2439
-				dqopt->info[cnt].dqi_fmt_id, flags);
2440
-		iput(inode);
2531
+		ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id,
2532
+					  flags);
2533
+		if (ret < 0)
2534
+			vfs_cleanup_quota_inode(sb, cnt);
24412535 	}
24422536 
24432537 	return ret;
....@@ -2454,47 +2548,12 @@
24542548 	if (path->dentry->d_sb != sb)
24552549 		error = -EXDEV;
24562550 	else
2457
-		error = vfs_load_quota_inode(d_inode(path->dentry), type,
2551
+		error = dquot_load_quota_inode(d_inode(path->dentry), type,
24582552 					     format_id, DQUOT_USAGE_ENABLED |
24592553 					     DQUOT_LIMITS_ENABLED);
24602554 	return error;
24612555 }
24622556 EXPORT_SYMBOL(dquot_quota_on);
2463
-
2464
-/*
2465
- * More powerful function for turning on quotas allowing setting
2466
- * of individual quota flags
2467
- */
2468
-int dquot_enable(struct inode *inode, int type, int format_id,
2469
-		 unsigned int flags)
2470
-{
2471
-	struct super_block *sb = inode->i_sb;
2472
-
2473
-	/* Just unsuspend quotas? */
2474
-	BUG_ON(flags & DQUOT_SUSPENDED);
2475
-	/* s_umount should be held in exclusive mode */
2476
-	if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
2477
-		up_read(&sb->s_umount);
2478
-
2479
-	if (!flags)
2480
-		return 0;
2481
-	/* Just updating flags needed? */
2482
-	if (sb_has_quota_loaded(sb, type)) {
2483
-		if (flags & DQUOT_USAGE_ENABLED &&
2484
-		    sb_has_quota_usage_enabled(sb, type))
2485
-			return -EBUSY;
2486
-		if (flags & DQUOT_LIMITS_ENABLED &&
2487
-		    sb_has_quota_limits_enabled(sb, type))
2488
-			return -EBUSY;
2489
-		spin_lock(&dq_state_lock);
2490
-		sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
2491
-		spin_unlock(&dq_state_lock);
2492
-		return 0;
2493
-	}
2494
-
2495
-	return vfs_load_quota_inode(inode, type, format_id, flags);
2496
-}
2497
-EXPORT_SYMBOL(dquot_enable);
24982557 
24992558 /*
25002559  * This function is used when filesystem needs to initialize quotas
....@@ -2506,21 +2565,15 @@
25062565 	struct dentry *dentry;
25072566 	int error;
25082567 
2509
-	dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
2568
+	dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name));
25102569 	if (IS_ERR(dentry))
25112570 		return PTR_ERR(dentry);
25122571 
2513
-	if (d_really_is_negative(dentry)) {
2514
-		error = -ENOENT;
2515
-		goto out;
2516
-	}
2517
-
25182572 	error = security_quota_on(dentry);
25192573 	if (!error)
2520
-		error = vfs_load_quota_inode(d_inode(dentry), type, format_id,
2574
+		error = dquot_load_quota_inode(d_inode(dentry), type, format_id,
25212575 				DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
25222576 
2523
-out:
25242577 	dput(dentry);
25252578 	return error;
25262579 }
....@@ -2542,13 +2595,17 @@
25422595 		if (!(flags & qtype_enforce_flag(type)))
25432596 			continue;
25442597 		/* Can't enforce without accounting */
2545
-		if (!sb_has_quota_usage_enabled(sb, type))
2546
-			return -EINVAL;
2547
-		ret = dquot_enable(dqopt->files[type], type,
2548
-				   dqopt->info[type].dqi_fmt_id,
2549
-				   DQUOT_LIMITS_ENABLED);
2550
-		if (ret < 0)
2598
+		if (!sb_has_quota_usage_enabled(sb, type)) {
2599
+			ret = -EINVAL;
25512600 			goto out_err;
2601
+		}
2602
+		if (sb_has_quota_limits_enabled(sb, type)) {
2603
+			ret = -EBUSY;
2604
+			goto out_err;
2605
+		}
2606
+		spin_lock(&dq_state_lock);
2607
+		dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
2608
+		spin_unlock(&dq_state_lock);
25522609 	}
25532610 	return 0;
25542611 out_err:
....@@ -2598,10 +2655,12 @@
25982655 out_err:
25992656 	/* Backout enforcement disabling we already did */
26002657 	for (type--; type >= 0; type--)  {
2601
-		if (flags & qtype_enforce_flag(type))
2602
-			dquot_enable(dqopt->files[type], type,
2603
-				     dqopt->info[type].dqi_fmt_id,
2604
-				     DQUOT_LIMITS_ENABLED);
2658
+		if (flags & qtype_enforce_flag(type)) {
2659
+			spin_lock(&dq_state_lock);
2660
+			dqopt->flags |=
2661
+				dquot_state_flag(DQUOT_LIMITS_ENABLED, type);
2662
+			spin_unlock(&dq_state_lock);
2663
+		}
26052664 	}
26062665 	return ret;
26072666 }
....@@ -2730,7 +2789,7 @@
27302789 
27312790 	if (check_blim) {
27322791 		if (!dm->dqb_bsoftlimit ||
2733
-		    dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) {
2792
+		    dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) {
27342793 			dm->dqb_btime = 0;
27352794 			clear_bit(DQ_BLKS_B, &dquot->dq_flags);
27362795 		} else if (!(di->d_fieldmask & QC_SPC_TIMER))
....@@ -2739,7 +2798,7 @@
27392798 	}
27402799 	if (check_ilim) {
27412800 		if (!dm->dqb_isoftlimit ||
2742
-		    dm->dqb_curinodes < dm->dqb_isoftlimit) {
2801
+		    dm->dqb_curinodes <= dm->dqb_isoftlimit) {
27432802 			dm->dqb_itime = 0;
27442803 			clear_bit(DQ_INODES_B, &dquot->dq_flags);
27452804 		} else if (!(di->d_fieldmask & QC_INO_TIMER))
....@@ -2782,7 +2841,7 @@
27822841 	struct qc_type_state *tstate;
27832842 	struct quota_info *dqopt = sb_dqopt(sb);
27842843 	int type;
2785
-  
2844
+
27862845 	memset(state, 0, sizeof(*state));
27872846 	for (type = 0; type < MAXQUOTAS; type++) {
27882847 		if (!sb_has_quota_active(sb, type))
....@@ -2799,8 +2858,10 @@
27992858 			tstate->flags |= QCI_LIMITS_ENFORCED;
28002859 		tstate->spc_timelimit = mi->dqi_bgrace;
28012860 		tstate->ino_timelimit = mi->dqi_igrace;
2802
-		tstate->ino = dqopt->files[type]->i_ino;
2803
-		tstate->blocks = dqopt->files[type]->i_blocks;
2861
+		if (dqopt->files[type]) {
2862
+			tstate->ino = dqopt->files[type]->i_ino;
2863
+			tstate->blocks = dqopt->files[type]->i_blocks;
2864
+		}
28042865 		tstate->nextents = 1;	/* We don't know... */
28052866 		spin_unlock(&dq_data_lock);
28062867 	}
....@@ -2857,7 +2918,7 @@
28572918 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
28582919 
28592920 static int do_proc_dqstats(struct ctl_table *table, int write,
2860
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
2921
+		     void *buffer, size_t *lenp, loff_t *ppos)
28612922 {
28622923 	unsigned int type = (unsigned long *)table->data - dqstats.stat;
28632924 	s64 value = percpu_counter_sum(&dqstats.counter[type]);
....@@ -2987,11 +3048,7 @@
29873048 
29883049 	/* Find power-of-two hlist_heads which can fit into allocation */
29893050 	nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
2990
-	dq_hash_bits = 0;
2991
-	do {
2992
-		dq_hash_bits++;
2993
-	} while (nr_hash >> dq_hash_bits);
2994
-	dq_hash_bits--;
3051
+	dq_hash_bits = ilog2(nr_hash);
29953052 
29963053 	nr_hash = 1UL << dq_hash_bits;
29973054 	dq_hash_mask = nr_hash - 1;