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-rw-r--r--block/blk-core.c20
-rw-r--r--block/blk-merge.c9
-rw-r--r--block/genhd.c218
-rw-r--r--block/ioctl.c26
-rw-r--r--drivers/block/aoe/aoecmd.c6
-rw-r--r--fs/block_dev.c15
-rw-r--r--fs/partitions/check.c70
-rw-r--r--include/linux/genhd.h53
8 files changed, 323 insertions, 94 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index a0dc2e72fcbb..d6128d9ad601 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -60,7 +60,9 @@ static void drive_stat_acct(struct request *rq, int new_io)
60 if (!blk_fs_request(rq) || !rq->rq_disk) 60 if (!blk_fs_request(rq) || !rq->rq_disk)
61 return; 61 return;
62 62
63 part = disk_map_sector(rq->rq_disk, rq->sector); 63 rcu_read_lock();
64
65 part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
64 if (!new_io) 66 if (!new_io)
65 __all_stat_inc(rq->rq_disk, part, merges[rw], rq->sector); 67 __all_stat_inc(rq->rq_disk, part, merges[rw], rq->sector);
66 else { 68 else {
@@ -71,6 +73,8 @@ static void drive_stat_acct(struct request *rq, int new_io)
71 part->in_flight++; 73 part->in_flight++;
72 } 74 }
73 } 75 }
76
77 rcu_read_unlock();
74} 78}
75 79
76void blk_queue_congestion_threshold(struct request_queue *q) 80void blk_queue_congestion_threshold(struct request_queue *q)
@@ -1557,12 +1561,14 @@ static int __end_that_request_first(struct request *req, int error,
1557 } 1561 }
1558 1562
1559 if (blk_fs_request(req) && req->rq_disk) { 1563 if (blk_fs_request(req) && req->rq_disk) {
1560 struct hd_struct *part =
1561 disk_map_sector(req->rq_disk, req->sector);
1562 const int rw = rq_data_dir(req); 1564 const int rw = rq_data_dir(req);
1565 struct hd_struct *part;
1563 1566
1567 rcu_read_lock();
1568 part = disk_map_sector_rcu(req->rq_disk, req->sector);
1564 all_stat_add(req->rq_disk, part, sectors[rw], 1569 all_stat_add(req->rq_disk, part, sectors[rw],
1565 nr_bytes >> 9, req->sector); 1570 nr_bytes >> 9, req->sector);
1571 rcu_read_unlock();
1566 } 1572 }
1567 1573
1568 total_bytes = bio_nbytes = 0; 1574 total_bytes = bio_nbytes = 0;
@@ -1746,7 +1752,11 @@ static void end_that_request_last(struct request *req, int error)
1746 if (disk && blk_fs_request(req) && req != &req->q->bar_rq) { 1752 if (disk && blk_fs_request(req) && req != &req->q->bar_rq) {
1747 unsigned long duration = jiffies - req->start_time; 1753 unsigned long duration = jiffies - req->start_time;
1748 const int rw = rq_data_dir(req); 1754 const int rw = rq_data_dir(req);
1749 struct hd_struct *part = disk_map_sector(disk, req->sector); 1755 struct hd_struct *part;
1756
1757 rcu_read_lock();
1758
1759 part = disk_map_sector_rcu(disk, req->sector);
1750 1760
1751 __all_stat_inc(disk, part, ios[rw], req->sector); 1761 __all_stat_inc(disk, part, ios[rw], req->sector);
1752 __all_stat_add(disk, part, ticks[rw], duration, req->sector); 1762 __all_stat_add(disk, part, ticks[rw], duration, req->sector);
@@ -1756,6 +1766,8 @@ static void end_that_request_last(struct request *req, int error)
1756 part_round_stats(part); 1766 part_round_stats(part);
1757 part->in_flight--; 1767 part->in_flight--;
1758 } 1768 }
1769
1770 rcu_read_unlock();
1759 } 1771 }
1760 1772
1761 if (req->end_io) 1773 if (req->end_io)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 9b17da698d7c..eb2a3ca58303 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -387,14 +387,19 @@ static int attempt_merge(struct request_queue *q, struct request *req,
387 elv_merge_requests(q, req, next); 387 elv_merge_requests(q, req, next);
388 388
389 if (req->rq_disk) { 389 if (req->rq_disk) {
390 struct hd_struct *part = 390 struct hd_struct *part;
391 disk_map_sector(req->rq_disk, req->sector); 391
392 rcu_read_lock();
393
394 part = disk_map_sector_rcu(req->rq_disk, req->sector);
392 disk_round_stats(req->rq_disk); 395 disk_round_stats(req->rq_disk);
393 req->rq_disk->in_flight--; 396 req->rq_disk->in_flight--;
394 if (part) { 397 if (part) {
395 part_round_stats(part); 398 part_round_stats(part);
396 part->in_flight--; 399 part->in_flight--;
397 } 400 }
401
402 rcu_read_unlock();
398 } 403 }
399 404
400 req->ioprio = ioprio_best(req->ioprio, next->ioprio); 405 req->ioprio = ioprio_best(req->ioprio, next->ioprio);
diff --git a/block/genhd.c b/block/genhd.c
index fa32d09fda24..b431d6543942 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -26,6 +26,158 @@ struct kobject *block_depr;
26 26
27static struct device_type disk_type; 27static struct device_type disk_type;
28 28
29/**
30 * disk_get_part - get partition
31 * @disk: disk to look partition from
32 * @partno: partition number
33 *
34 * Look for partition @partno from @disk. If found, increment
35 * reference count and return it.
36 *
37 * CONTEXT:
38 * Don't care.
39 *
40 * RETURNS:
41 * Pointer to the found partition on success, NULL if not found.
42 */
43struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
44{
45 struct hd_struct *part;
46
47 if (unlikely(partno < 1 || partno > disk_max_parts(disk)))
48 return NULL;
49 rcu_read_lock();
50 part = rcu_dereference(disk->__part[partno - 1]);
51 if (part)
52 get_device(&part->dev);
53 rcu_read_unlock();
54
55 return part;
56}
57EXPORT_SYMBOL_GPL(disk_get_part);
58
59/**
60 * disk_part_iter_init - initialize partition iterator
61 * @piter: iterator to initialize
62 * @disk: disk to iterate over
63 * @flags: DISK_PITER_* flags
64 *
65 * Initialize @piter so that it iterates over partitions of @disk.
66 *
67 * CONTEXT:
68 * Don't care.
69 */
70void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
71 unsigned int flags)
72{
73 piter->disk = disk;
74 piter->part = NULL;
75
76 if (flags & DISK_PITER_REVERSE)
77 piter->idx = disk_max_parts(piter->disk) - 1;
78 else
79 piter->idx = 0;
80
81 piter->flags = flags;
82}
83EXPORT_SYMBOL_GPL(disk_part_iter_init);
84
85/**
86 * disk_part_iter_next - proceed iterator to the next partition and return it
87 * @piter: iterator of interest
88 *
89 * Proceed @piter to the next partition and return it.
90 *
91 * CONTEXT:
92 * Don't care.
93 */
94struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
95{
96 int inc, end;
97
98 /* put the last partition */
99 disk_put_part(piter->part);
100 piter->part = NULL;
101
102 rcu_read_lock();
103
104 /* determine iteration parameters */
105 if (piter->flags & DISK_PITER_REVERSE) {
106 inc = -1;
107 end = -1;
108 } else {
109 inc = 1;
110 end = disk_max_parts(piter->disk);
111 }
112
113 /* iterate to the next partition */
114 for (; piter->idx != end; piter->idx += inc) {
115 struct hd_struct *part;
116
117 part = rcu_dereference(piter->disk->__part[piter->idx]);
118 if (!part)
119 continue;
120 if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
121 continue;
122
123 get_device(&part->dev);
124 piter->part = part;
125 piter->idx += inc;
126 break;
127 }
128
129 rcu_read_unlock();
130
131 return piter->part;
132}
133EXPORT_SYMBOL_GPL(disk_part_iter_next);
134
135/**
136 * disk_part_iter_exit - finish up partition iteration
137 * @piter: iter of interest
138 *
139 * Called when iteration is over. Cleans up @piter.
140 *
141 * CONTEXT:
142 * Don't care.
143 */
144void disk_part_iter_exit(struct disk_part_iter *piter)
145{
146 disk_put_part(piter->part);
147 piter->part = NULL;
148}
149EXPORT_SYMBOL_GPL(disk_part_iter_exit);
150
151/**
152 * disk_map_sector_rcu - map sector to partition
153 * @disk: gendisk of interest
154 * @sector: sector to map
155 *
156 * Find out which partition @sector maps to on @disk. This is
157 * primarily used for stats accounting.
158 *
159 * CONTEXT:
160 * RCU read locked. The returned partition pointer is valid only
161 * while preemption is disabled.
162 *
163 * RETURNS:
164 * Found partition on success, NULL if there's no matching partition.
165 */
166struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
167{
168 int i;
169
170 for (i = 0; i < disk_max_parts(disk); i++) {
171 struct hd_struct *part = rcu_dereference(disk->__part[i]);
172
173 if (part && part->start_sect <= sector &&
174 sector < part->start_sect + part->nr_sects)
175 return part;
176 }
177 return NULL;
178}
179EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
180
29/* 181/*
30 * Can be deleted altogether. Later. 182 * Can be deleted altogether. Later.
31 * 183 *
@@ -245,10 +397,12 @@ extern struct block_device *bdget_disk(struct gendisk *disk, int partno)
245 if (partno == 0) 397 if (partno == 0)
246 devt = disk_devt(disk); 398 devt = disk_devt(disk);
247 else { 399 else {
248 struct hd_struct *part = disk->part[partno - 1]; 400 struct hd_struct *part;
249 401
402 part = disk_get_part(disk, partno);
250 if (part && part->nr_sects) 403 if (part && part->nr_sects)
251 devt = part_devt(part); 404 devt = part_devt(part);
405 disk_put_part(part);
252 } 406 }
253 407
254 if (likely(devt != MKDEV(0, 0))) 408 if (likely(devt != MKDEV(0, 0)))
@@ -270,8 +424,9 @@ void __init printk_all_partitions(void)
270 class_dev_iter_init(&iter, &block_class, NULL, &disk_type); 424 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
271 while ((dev = class_dev_iter_next(&iter))) { 425 while ((dev = class_dev_iter_next(&iter))) {
272 struct gendisk *disk = dev_to_disk(dev); 426 struct gendisk *disk = dev_to_disk(dev);
427 struct disk_part_iter piter;
428 struct hd_struct *part;
273 char buf[BDEVNAME_SIZE]; 429 char buf[BDEVNAME_SIZE];
274 int n;
275 430
276 /* 431 /*
277 * Don't show empty devices or things that have been 432 * Don't show empty devices or things that have been
@@ -298,16 +453,13 @@ void __init printk_all_partitions(void)
298 printk(" (driver?)\n"); 453 printk(" (driver?)\n");
299 454
300 /* now show the partitions */ 455 /* now show the partitions */
301 for (n = 0; n < disk_max_parts(disk); ++n) { 456 disk_part_iter_init(&piter, disk, 0);
302 struct hd_struct *part = disk->part[n]; 457 while ((part = disk_part_iter_next(&piter)))
303
304 if (!part || !part->nr_sects)
305 continue;
306 printk(" %02x%02x %10llu %s\n", 458 printk(" %02x%02x %10llu %s\n",
307 MAJOR(part_devt(part)), MINOR(part_devt(part)), 459 MAJOR(part_devt(part)), MINOR(part_devt(part)),
308 (unsigned long long)part->nr_sects >> 1, 460 (unsigned long long)part->nr_sects >> 1,
309 disk_name(disk, part->partno, buf)); 461 disk_name(disk, part->partno, buf));
310 } 462 disk_part_iter_exit(&piter);
311 } 463 }
312 class_dev_iter_exit(&iter); 464 class_dev_iter_exit(&iter);
313} 465}
@@ -371,7 +523,8 @@ static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
371static int show_partition(struct seq_file *seqf, void *v) 523static int show_partition(struct seq_file *seqf, void *v)
372{ 524{
373 struct gendisk *sgp = v; 525 struct gendisk *sgp = v;
374 int n; 526 struct disk_part_iter piter;
527 struct hd_struct *part;
375 char buf[BDEVNAME_SIZE]; 528 char buf[BDEVNAME_SIZE];
376 529
377 /* Don't show non-partitionable removeable devices or empty devices */ 530 /* Don't show non-partitionable removeable devices or empty devices */
@@ -386,17 +539,14 @@ static int show_partition(struct seq_file *seqf, void *v)
386 MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)), 539 MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)),
387 (unsigned long long)get_capacity(sgp) >> 1, 540 (unsigned long long)get_capacity(sgp) >> 1,
388 disk_name(sgp, 0, buf)); 541 disk_name(sgp, 0, buf));
389 for (n = 0; n < disk_max_parts(sgp); n++) { 542
390 struct hd_struct *part = sgp->part[n]; 543 disk_part_iter_init(&piter, sgp, 0);
391 if (!part) 544 while ((part = disk_part_iter_next(&piter)))
392 continue;
393 if (part->nr_sects == 0)
394 continue;
395 seq_printf(seqf, "%4d %4d %10llu %s\n", 545 seq_printf(seqf, "%4d %4d %10llu %s\n",
396 MAJOR(part_devt(part)), MINOR(part_devt(part)), 546 MAJOR(part_devt(part)), MINOR(part_devt(part)),
397 (unsigned long long)part->nr_sects >> 1, 547 (unsigned long long)part->nr_sects >> 1,
398 disk_name(sgp, part->partno, buf)); 548 disk_name(sgp, part->partno, buf));
399 } 549 disk_part_iter_exit(&piter);
400 550
401 return 0; 551 return 0;
402} 552}
@@ -571,7 +721,7 @@ static void disk_release(struct device *dev)
571 struct gendisk *disk = dev_to_disk(dev); 721 struct gendisk *disk = dev_to_disk(dev);
572 722
573 kfree(disk->random); 723 kfree(disk->random);
574 kfree(disk->part); 724 kfree(disk->__part);
575 free_disk_stats(disk); 725 free_disk_stats(disk);
576 kfree(disk); 726 kfree(disk);
577} 727}
@@ -596,8 +746,9 @@ static struct device_type disk_type = {
596static int diskstats_show(struct seq_file *seqf, void *v) 746static int diskstats_show(struct seq_file *seqf, void *v)
597{ 747{
598 struct gendisk *gp = v; 748 struct gendisk *gp = v;
749 struct disk_part_iter piter;
750 struct hd_struct *hd;
599 char buf[BDEVNAME_SIZE]; 751 char buf[BDEVNAME_SIZE];
600 int n;
601 752
602 /* 753 /*
603 if (&gp->dev.kobj.entry == block_class.devices.next) 754 if (&gp->dev.kobj.entry == block_class.devices.next)
@@ -624,12 +775,8 @@ static int diskstats_show(struct seq_file *seqf, void *v)
624 jiffies_to_msecs(disk_stat_read(gp, time_in_queue))); 775 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
625 776
626 /* now show all non-0 size partitions of it */ 777 /* now show all non-0 size partitions of it */
627 for (n = 0; n < disk_max_parts(gp); n++) { 778 disk_part_iter_init(&piter, gp, 0);
628 struct hd_struct *hd = gp->part[n]; 779 while ((hd = disk_part_iter_next(&piter))) {
629
630 if (!hd || !hd->nr_sects)
631 continue;
632
633 preempt_disable(); 780 preempt_disable();
634 part_round_stats(hd); 781 part_round_stats(hd);
635 preempt_enable(); 782 preempt_enable();
@@ -650,6 +797,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
650 jiffies_to_msecs(part_stat_read(hd, time_in_queue)) 797 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
651 ); 798 );
652 } 799 }
800 disk_part_iter_exit(&piter);
653 801
654 return 0; 802 return 0;
655} 803}
@@ -703,12 +851,16 @@ dev_t blk_lookup_devt(const char *name, int partno)
703 if (partno == 0) 851 if (partno == 0)
704 devt = disk_devt(disk); 852 devt = disk_devt(disk);
705 else { 853 else {
706 struct hd_struct *part = disk->part[partno - 1]; 854 struct hd_struct *part;
707 855
708 if (!part || !part->nr_sects) 856 part = disk_get_part(disk, partno);
857 if (!part || !part->nr_sects) {
858 disk_put_part(part);
709 continue; 859 continue;
860 }
710 861
711 devt = part_devt(part); 862 devt = part_devt(part);
863 disk_put_part(part);
712 } 864 }
713 break; 865 break;
714 } 866 }
@@ -735,9 +887,9 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
735 } 887 }
736 if (minors > 1) { 888 if (minors > 1) {
737 int size = (minors - 1) * sizeof(struct hd_struct *); 889 int size = (minors - 1) * sizeof(struct hd_struct *);
738 disk->part = kmalloc_node(size, 890 disk->__part = kmalloc_node(size,
739 GFP_KERNEL | __GFP_ZERO, node_id); 891 GFP_KERNEL | __GFP_ZERO, node_id);
740 if (!disk->part) { 892 if (!disk->__part) {
741 free_disk_stats(disk); 893 free_disk_stats(disk);
742 kfree(disk); 894 kfree(disk);
743 return NULL; 895 return NULL;
@@ -798,10 +950,14 @@ EXPORT_SYMBOL(set_device_ro);
798 950
799void set_disk_ro(struct gendisk *disk, int flag) 951void set_disk_ro(struct gendisk *disk, int flag)
800{ 952{
801 int i; 953 struct disk_part_iter piter;
954 struct hd_struct *part;
955
802 disk->policy = flag; 956 disk->policy = flag;
803 for (i = 0; i < disk_max_parts(disk); i++) 957 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
804 if (disk->part[i]) disk->part[i]->policy = flag; 958 while ((part = disk_part_iter_next(&piter)))
959 part->policy = flag;
960 disk_part_iter_exit(&piter);
805} 961}
806 962
807EXPORT_SYMBOL(set_disk_ro); 963EXPORT_SYMBOL(set_disk_ro);
diff --git a/block/ioctl.c b/block/ioctl.c
index 403f7d7e0c28..a5f672ad55f6 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -12,11 +12,12 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
12{ 12{
13 struct block_device *bdevp; 13 struct block_device *bdevp;
14 struct gendisk *disk; 14 struct gendisk *disk;
15 struct hd_struct *part;
15 struct blkpg_ioctl_arg a; 16 struct blkpg_ioctl_arg a;
16 struct blkpg_partition p; 17 struct blkpg_partition p;
18 struct disk_part_iter piter;
17 long long start, length; 19 long long start, length;
18 int partno; 20 int partno;
19 int i;
20 int err; 21 int err;
21 22
22 if (!capable(CAP_SYS_ADMIN)) 23 if (!capable(CAP_SYS_ADMIN))
@@ -47,28 +48,33 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
47 mutex_lock(&bdev->bd_mutex); 48 mutex_lock(&bdev->bd_mutex);
48 49
49 /* overlap? */ 50 /* overlap? */
50 for (i = 0; i < disk_max_parts(disk); i++) { 51 disk_part_iter_init(&piter, disk,
51 struct hd_struct *s = disk->part[i]; 52 DISK_PITER_INCL_EMPTY);
52 53 while ((part = disk_part_iter_next(&piter))) {
53 if (!s) 54 if (!(start + length <= part->start_sect ||
54 continue; 55 start >= part->start_sect + part->nr_sects)) {
55 if (!(start+length <= s->start_sect || 56 disk_part_iter_exit(&piter);
56 start >= s->start_sect + s->nr_sects)) {
57 mutex_unlock(&bdev->bd_mutex); 57 mutex_unlock(&bdev->bd_mutex);
58 return -EBUSY; 58 return -EBUSY;
59 } 59 }
60 } 60 }
61 disk_part_iter_exit(&piter);
62
61 /* all seems OK */ 63 /* all seems OK */
62 err = add_partition(disk, partno, start, length, 64 err = add_partition(disk, partno, start, length,
63 ADDPART_FLAG_NONE); 65 ADDPART_FLAG_NONE);
64 mutex_unlock(&bdev->bd_mutex); 66 mutex_unlock(&bdev->bd_mutex);
65 return err; 67 return err;
66 case BLKPG_DEL_PARTITION: 68 case BLKPG_DEL_PARTITION:
67 if (!disk->part[partno - 1]) 69 part = disk_get_part(disk, partno);
70 if (!part)
68 return -ENXIO; 71 return -ENXIO;
69 bdevp = bdget_disk(disk, partno); 72
73 bdevp = bdget(part_devt(part));
74 disk_put_part(part);
70 if (!bdevp) 75 if (!bdevp)
71 return -ENOMEM; 76 return -ENOMEM;
77
72 mutex_lock(&bdevp->bd_mutex); 78 mutex_lock(&bdevp->bd_mutex);
73 if (bdevp->bd_openers) { 79 if (bdevp->bd_openers) {
74 mutex_unlock(&bdevp->bd_mutex); 80 mutex_unlock(&bdevp->bd_mutex);
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 885d1409521f..84c03d65dcc5 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -757,11 +757,15 @@ diskstats(struct gendisk *disk, struct bio *bio, ulong duration, sector_t sector
757 const int rw = bio_data_dir(bio); 757 const int rw = bio_data_dir(bio);
758 struct hd_struct *part; 758 struct hd_struct *part;
759 759
760 part = disk_map_sector(disk, sector); 760 rcu_read_lock();
761
762 part = disk_map_sector_rcu(disk, sector);
761 all_stat_inc(disk, part, ios[rw], sector); 763 all_stat_inc(disk, part, ios[rw], sector);
762 all_stat_add(disk, part, ticks[rw], duration, sector); 764 all_stat_add(disk, part, ticks[rw], duration, sector);
763 all_stat_add(disk, part, sectors[rw], n_sect, sector); 765 all_stat_add(disk, part, sectors[rw], n_sect, sector);
764 all_stat_add(disk, part, io_ticks, duration, sector); 766 all_stat_add(disk, part, io_ticks, duration, sector);
767
768 rcu_read_unlock();
765} 769}
766 770
767void 771void
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 72e0a2887cb7..2f2873b9a041 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -929,6 +929,7 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
929{ 929{
930 struct module *owner = NULL; 930 struct module *owner = NULL;
931 struct gendisk *disk; 931 struct gendisk *disk;
932 struct hd_struct *part = NULL;
932 int ret; 933 int ret;
933 int partno; 934 int partno;
934 int perm = 0; 935 int perm = 0;
@@ -978,7 +979,6 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
978 if (bdev->bd_invalidated) 979 if (bdev->bd_invalidated)
979 rescan_partitions(disk, bdev); 980 rescan_partitions(disk, bdev);
980 } else { 981 } else {
981 struct hd_struct *p;
982 struct block_device *whole; 982 struct block_device *whole;
983 whole = bdget_disk(disk, 0); 983 whole = bdget_disk(disk, 0);
984 ret = -ENOMEM; 984 ret = -ENOMEM;
@@ -989,16 +989,16 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
989 if (ret) 989 if (ret)
990 goto out_first; 990 goto out_first;
991 bdev->bd_contains = whole; 991 bdev->bd_contains = whole;
992 p = disk->part[partno - 1]; 992 part = disk_get_part(disk, partno);
993 bdev->bd_inode->i_data.backing_dev_info = 993 bdev->bd_inode->i_data.backing_dev_info =
994 whole->bd_inode->i_data.backing_dev_info; 994 whole->bd_inode->i_data.backing_dev_info;
995 if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) { 995 if (!(disk->flags & GENHD_FL_UP) ||
996 !part || !part->nr_sects) {
996 ret = -ENXIO; 997 ret = -ENXIO;
997 goto out_first; 998 goto out_first;
998 } 999 }
999 kobject_get(&p->dev.kobj); 1000 bdev->bd_part = part;
1000 bdev->bd_part = p; 1001 bd_set_size(bdev, (loff_t)part->nr_sects << 9);
1001 bd_set_size(bdev, (loff_t) p->nr_sects << 9);
1002 } 1002 }
1003 } else { 1003 } else {
1004 put_disk(disk); 1004 put_disk(disk);
@@ -1027,6 +1027,7 @@ out_first:
1027 __blkdev_put(bdev->bd_contains, 1); 1027 __blkdev_put(bdev->bd_contains, 1);
1028 bdev->bd_contains = NULL; 1028 bdev->bd_contains = NULL;
1029 put_disk(disk); 1029 put_disk(disk);
1030 disk_put_part(part);
1030 module_put(owner); 1031 module_put(owner);
1031out: 1032out:
1032 mutex_unlock(&bdev->bd_mutex); 1033 mutex_unlock(&bdev->bd_mutex);
@@ -1119,7 +1120,7 @@ static int __blkdev_put(struct block_device *bdev, int for_part)
1119 module_put(owner); 1120 module_put(owner);
1120 1121
1121 if (bdev->bd_contains != bdev) { 1122 if (bdev->bd_contains != bdev) {
1122 kobject_put(&bdev->bd_part->dev.kobj); 1123 disk_put_part(bdev->bd_part);
1123 bdev->bd_part = NULL; 1124 bdev->bd_part = NULL;
1124 } 1125 }
1125 bdev->bd_disk = NULL; 1126 bdev->bd_disk = NULL;
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index e77fa144a07d..96c8bf41e455 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -314,19 +314,29 @@ static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
314 kobject_put(k); 314 kobject_put(k);
315} 315}
316 316
317static void delete_partition_rcu_cb(struct rcu_head *head)
318{
319 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
320
321 part->start_sect = 0;
322 part->nr_sects = 0;
323 part_stat_set_all(part, 0);
324 put_device(&part->dev);
325}
326
317void delete_partition(struct gendisk *disk, int partno) 327void delete_partition(struct gendisk *disk, int partno)
318{ 328{
319 struct hd_struct *p = disk->part[partno - 1]; 329 struct hd_struct *part;
320 330
321 if (!p) 331 part = disk->__part[partno-1];
332 if (!part)
322 return; 333 return;
323 disk->part[partno - 1] = NULL; 334
324 p->start_sect = 0; 335 rcu_assign_pointer(disk->__part[partno-1], NULL);
325 p->nr_sects = 0; 336 kobject_put(part->holder_dir);
326 part_stat_set_all(p, 0); 337 device_del(&part->dev);
327 kobject_put(p->holder_dir); 338
328 device_del(&p->dev); 339 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
329 put_device(&p->dev);
330} 340}
331 341
332static ssize_t whole_disk_show(struct device *dev, 342static ssize_t whole_disk_show(struct device *dev,
@@ -343,7 +353,7 @@ int add_partition(struct gendisk *disk, int partno,
343 struct hd_struct *p; 353 struct hd_struct *p;
344 int err; 354 int err;
345 355
346 if (disk->part[partno - 1]) 356 if (disk->__part[partno - 1])
347 return -EBUSY; 357 return -EBUSY;
348 358
349 p = kzalloc(sizeof(*p), GFP_KERNEL); 359 p = kzalloc(sizeof(*p), GFP_KERNEL);
@@ -391,7 +401,8 @@ int add_partition(struct gendisk *disk, int partno,
391 } 401 }
392 402
393 /* everything is up and running, commence */ 403 /* everything is up and running, commence */
394 disk->part[partno - 1] = p; 404 INIT_RCU_HEAD(&p->rcu_head);
405 rcu_assign_pointer(disk->__part[partno - 1], p);
395 406
396 /* suppress uevent if the disk supresses it */ 407 /* suppress uevent if the disk supresses it */
397 if (!disk->dev.uevent_suppress) 408 if (!disk->dev.uevent_suppress)
@@ -414,9 +425,9 @@ out_put:
414void register_disk(struct gendisk *disk) 425void register_disk(struct gendisk *disk)
415{ 426{
416 struct block_device *bdev; 427 struct block_device *bdev;
428 struct disk_part_iter piter;
429 struct hd_struct *part;
417 char *s; 430 char *s;
418 int i;
419 struct hd_struct *p;
420 int err; 431 int err;
421 432
422 disk->dev.parent = disk->driverfs_dev; 433 disk->dev.parent = disk->driverfs_dev;
@@ -466,16 +477,16 @@ exit:
466 kobject_uevent(&disk->dev.kobj, KOBJ_ADD); 477 kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
467 478
468 /* announce possible partitions */ 479 /* announce possible partitions */
469 for (i = 0; i < disk_max_parts(disk); i++) { 480 disk_part_iter_init(&piter, disk, 0);
470 p = disk->part[i]; 481 while ((part = disk_part_iter_next(&piter)))
471 if (!p || !p->nr_sects) 482 kobject_uevent(&part->dev.kobj, KOBJ_ADD);
472 continue; 483 disk_part_iter_exit(&piter);
473 kobject_uevent(&p->dev.kobj, KOBJ_ADD);
474 }
475} 484}
476 485
477int rescan_partitions(struct gendisk *disk, struct block_device *bdev) 486int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
478{ 487{
488 struct disk_part_iter piter;
489 struct hd_struct *part;
479 struct parsed_partitions *state; 490 struct parsed_partitions *state;
480 int p, res; 491 int p, res;
481 492
@@ -485,8 +496,12 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
485 if (res) 496 if (res)
486 return res; 497 return res;
487 bdev->bd_invalidated = 0; 498 bdev->bd_invalidated = 0;
488 for (p = 1; p <= disk_max_parts(disk); p++) 499
489 delete_partition(disk, p); 500 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
501 while ((part = disk_part_iter_next(&piter)))
502 delete_partition(disk, part->partno);
503 disk_part_iter_exit(&piter);
504
490 if (disk->fops->revalidate_disk) 505 if (disk->fops->revalidate_disk)
491 disk->fops->revalidate_disk(disk); 506 disk->fops->revalidate_disk(disk);
492 if (!get_capacity(disk) || !(state = check_partition(disk, bdev))) 507 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
@@ -545,13 +560,18 @@ EXPORT_SYMBOL(read_dev_sector);
545 560
546void del_gendisk(struct gendisk *disk) 561void del_gendisk(struct gendisk *disk)
547{ 562{
548 int p; 563 struct disk_part_iter piter;
564 struct hd_struct *part;
549 565
550 /* invalidate stuff */ 566 /* invalidate stuff */
551 for (p = disk_max_parts(disk); p > 0; p--) { 567 disk_part_iter_init(&piter, disk,
552 invalidate_partition(disk, p); 568 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
553 delete_partition(disk, p); 569 while ((part = disk_part_iter_next(&piter))) {
570 invalidate_partition(disk, part->partno);
571 delete_partition(disk, part->partno);
554 } 572 }
573 disk_part_iter_exit(&piter);
574
555 invalidate_partition(disk, 0); 575 invalidate_partition(disk, 0);
556 disk->capacity = 0; 576 disk->capacity = 0;
557 disk->flags &= ~GENHD_FL_UP; 577 disk->flags &= ~GENHD_FL_UP;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 0ff75329199c..7fbba19e076b 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -11,6 +11,7 @@
11 11
12#include <linux/types.h> 12#include <linux/types.h>
13#include <linux/kdev_t.h> 13#include <linux/kdev_t.h>
14#include <linux/rcupdate.h>
14 15
15#ifdef CONFIG_BLOCK 16#ifdef CONFIG_BLOCK
16 17
@@ -100,6 +101,7 @@ struct hd_struct {
100#else 101#else
101 struct disk_stats dkstats; 102 struct disk_stats dkstats;
102#endif 103#endif
104 struct rcu_head rcu_head;
103}; 105};
104 106
105#define GENHD_FL_REMOVABLE 1 107#define GENHD_FL_REMOVABLE 1
@@ -120,7 +122,14 @@ struct gendisk {
120 * disks that can't be partitioned. */ 122 * disks that can't be partitioned. */
121 123
122 char disk_name[32]; /* name of major driver */ 124 char disk_name[32]; /* name of major driver */
123 struct hd_struct **part; /* [indexed by minor - 1] */ 125
126 /* Array of pointers to partitions indexed by partno - 1.
127 * Protected with matching bdev lock but stat and other
128 * non-critical accesses use RCU. Always access through
129 * helpers.
130 */
131 struct hd_struct **__part;
132
124 struct block_device_operations *fops; 133 struct block_device_operations *fops;
125 struct request_queue *queue; 134 struct request_queue *queue;
126 void *private_data; 135 void *private_data;
@@ -171,25 +180,41 @@ static inline dev_t part_devt(struct hd_struct *part)
171 return part->dev.devt; 180 return part->dev.devt;
172} 181}
173 182
183extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
184
185static inline void disk_put_part(struct hd_struct *part)
186{
187 if (likely(part))
188 put_device(&part->dev);
189}
190
191/*
192 * Smarter partition iterator without context limits.
193 */
194#define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
195#define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
196
197struct disk_part_iter {
198 struct gendisk *disk;
199 struct hd_struct *part;
200 int idx;
201 unsigned int flags;
202};
203
204extern void disk_part_iter_init(struct disk_part_iter *piter,
205 struct gendisk *disk, unsigned int flags);
206extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
207extern void disk_part_iter_exit(struct disk_part_iter *piter);
208
209extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
210 sector_t sector);
211
174/* 212/*
175 * Macros to operate on percpu disk statistics: 213 * Macros to operate on percpu disk statistics:
176 * 214 *
177 * The __ variants should only be called in critical sections. The full 215 * The __ variants should only be called in critical sections. The full
178 * variants disable/enable preemption. 216 * variants disable/enable preemption.
179 */ 217 */
180static inline struct hd_struct *disk_map_sector(struct gendisk *gendiskp,
181 sector_t sector)
182{
183 struct hd_struct *part;
184 int i;
185 for (i = 0; i < disk_max_parts(gendiskp); i++) {
186 part = gendiskp->part[i];
187 if (part && part->start_sect <= sector
188 && sector < part->start_sect + part->nr_sects)
189 return part;
190 }
191 return NULL;
192}
193 218
194#ifdef CONFIG_SMP 219#ifdef CONFIG_SMP
195#define __disk_stat_add(gendiskp, field, addnd) \ 220#define __disk_stat_add(gendiskp, field, addnd) \
generated by cgit v1.2.2 (git 2.25.0) at 2024-10-16 09:28:01 -0400