aboutsummaryrefslogtreecommitdiffstats
path: root/block/genhd.c
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2008-09-03 03:06:42 -0400
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 02:56:07 -0400
commitb5d0b9df0ba5d9a044f3a21e7544f53d90bd1465 (patch)
treed3347c1cfc59cf5d38c2c9adc2423f9d9b4cf818 /block/genhd.c
parented9e1982347b36573cd622ee5f4e2a7ccd79b3fd (diff)
block: introduce partition 0
genhd and partition code handled disk and partitions separately. All information about the whole disk was in struct genhd and partitions in struct hd_struct. However, the whole disk (part0) and other partitions have a lot in common and the data structures end up having good number of common fields and thus separate code paths doing the same thing. Also, the partition array was indexed by partno - 1 which gets pretty confusing at times. This patch introduces partition 0 and makes the partition array indexed by partno. Following patches will unify the handling of disk and parts piece-by-piece. This patch also implements disk_partitionable() which tests whether a disk is partitionable. With coming dynamic partition array change, the most common usage of disk_max_parts() will be testing whether a disk is partitionable and the number of max partitions will become much less important. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/genhd.c')
-rw-r--r--block/genhd.c40
1 files changed, 23 insertions, 17 deletions
diff --git a/block/genhd.c b/block/genhd.c
index 0a2f16bd54b7..65b7386c26d8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -54,10 +54,10 @@ struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
54{ 54{
55 struct hd_struct *part; 55 struct hd_struct *part;
56 56
57 if (unlikely(partno < 1 || partno > disk_max_parts(disk))) 57 if (unlikely(partno < 0 || partno >= disk_max_parts(disk)))
58 return NULL; 58 return NULL;
59 rcu_read_lock(); 59 rcu_read_lock();
60 part = rcu_dereference(disk->__part[partno - 1]); 60 part = rcu_dereference(disk->__part[partno]);
61 if (part) 61 if (part)
62 get_device(part_to_dev(part)); 62 get_device(part_to_dev(part));
63 rcu_read_unlock(); 63 rcu_read_unlock();
@@ -85,8 +85,10 @@ void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
85 85
86 if (flags & DISK_PITER_REVERSE) 86 if (flags & DISK_PITER_REVERSE)
87 piter->idx = disk_max_parts(piter->disk) - 1; 87 piter->idx = disk_max_parts(piter->disk) - 1;
88 else 88 else if (flags & DISK_PITER_INCL_PART0)
89 piter->idx = 0; 89 piter->idx = 0;
90 else
91 piter->idx = 1;
90 92
91 piter->flags = flags; 93 piter->flags = flags;
92} 94}
@@ -114,7 +116,10 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
114 /* determine iteration parameters */ 116 /* determine iteration parameters */
115 if (piter->flags & DISK_PITER_REVERSE) { 117 if (piter->flags & DISK_PITER_REVERSE) {
116 inc = -1; 118 inc = -1;
117 end = -1; 119 if (piter->flags & DISK_PITER_INCL_PART0)
120 end = -1;
121 else
122 end = 0;
118 } else { 123 } else {
119 inc = 1; 124 inc = 1;
120 end = disk_max_parts(piter->disk); 125 end = disk_max_parts(piter->disk);
@@ -177,7 +182,7 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
177{ 182{
178 int i; 183 int i;
179 184
180 for (i = 0; i < disk_max_parts(disk); i++) { 185 for (i = 1; i < disk_max_parts(disk); i++) {
181 struct hd_struct *part = rcu_dereference(disk->__part[i]); 186 struct hd_struct *part = rcu_dereference(disk->__part[i]);
182 187
183 if (part && part->start_sect <= sector && 188 if (part && part->start_sect <= sector &&
@@ -669,7 +674,7 @@ static int show_partition(struct seq_file *seqf, void *v)
669 char buf[BDEVNAME_SIZE]; 674 char buf[BDEVNAME_SIZE];
670 675
671 /* Don't show non-partitionable removeable devices or empty devices */ 676 /* Don't show non-partitionable removeable devices or empty devices */
672 if (!get_capacity(sgp) || (!disk_max_parts(sgp) && 677 if (!get_capacity(sgp) || (!disk_partitionable(sgp) &&
673 (sgp->flags & GENHD_FL_REMOVABLE))) 678 (sgp->flags & GENHD_FL_REMOVABLE)))
674 return 0; 679 return 0;
675 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) 680 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
@@ -742,7 +747,7 @@ static ssize_t disk_ext_range_show(struct device *dev,
742{ 747{
743 struct gendisk *disk = dev_to_disk(dev); 748 struct gendisk *disk = dev_to_disk(dev);
744 749
745 return sprintf(buf, "%d\n", disk_max_parts(disk) + 1); 750 return sprintf(buf, "%d\n", disk_max_parts(disk));
746} 751}
747 752
748static ssize_t disk_removable_show(struct device *dev, 753static ssize_t disk_removable_show(struct device *dev,
@@ -998,7 +1003,7 @@ dev_t blk_lookup_devt(const char *name, int partno)
998 1003
999 if (strcmp(dev->bus_id, name)) 1004 if (strcmp(dev->bus_id, name))
1000 continue; 1005 continue;
1001 if (partno < 0 || partno > disk_max_parts(disk)) 1006 if (partno < 0 || partno >= disk_max_parts(disk))
1002 continue; 1007 continue;
1003 1008
1004 if (partno == 0) 1009 if (partno == 0)
@@ -1045,21 +1050,22 @@ struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id)
1045 GFP_KERNEL | __GFP_ZERO, node_id); 1050 GFP_KERNEL | __GFP_ZERO, node_id);
1046 if (disk) { 1051 if (disk) {
1047 int tot_minors = minors + ext_minors; 1052 int tot_minors = minors + ext_minors;
1053 int size = tot_minors * sizeof(struct hd_struct *);
1048 1054
1049 if (!init_disk_stats(disk)) { 1055 if (!init_disk_stats(disk)) {
1050 kfree(disk); 1056 kfree(disk);
1051 return NULL; 1057 return NULL;
1052 } 1058 }
1053 if (tot_minors > 1) { 1059
1054 int size = (tot_minors - 1) * sizeof(struct hd_struct *); 1060 disk->__part = kmalloc_node(size, GFP_KERNEL | __GFP_ZERO,
1055 disk->__part = kmalloc_node(size, 1061 node_id);
1056 GFP_KERNEL | __GFP_ZERO, node_id); 1062 if (!disk->__part) {
1057 if (!disk->__part) { 1063 free_disk_stats(disk);
1058 free_disk_stats(disk); 1064 kfree(disk);
1059 kfree(disk); 1065 return NULL;
1060 return NULL;
1061 }
1062 } 1066 }
1067 disk->__part[0] = &disk->part0;
1068
1063 disk->minors = minors; 1069 disk->minors = minors;
1064 disk->ext_minors = ext_minors; 1070 disk->ext_minors = ext_minors;
1065 rand_initialize_disk(disk); 1071 rand_initialize_disk(disk);