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authorDavid Vrabel <david.vrabel@csr.com>2009-01-02 13:17:13 +0000
committerDavid Vrabel <david.vrabel@csr.com>2009-01-02 13:17:13 +0000
commitb21a207141d83a06abc5f492b80204602e02ca44 (patch)
treef0152cde543008c72d7eb5c12c18095ad92785e6 /block/genhd.c
parent3af373021fa32f8f787bfbdcc1a9277a287bde4e (diff)
parentb58602a4bac012b5f4fc12fe6b46ab237b610d5d (diff)
downloadlwn-b21a207141d83a06abc5f492b80204602e02ca44.tar.gz
lwn-b21a207141d83a06abc5f492b80204602e02ca44.zip
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-upstream
Conflicts: drivers/uwb/wlp/eda.c
Diffstat (limited to 'block/genhd.c')
-rw-r--r--block/genhd.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/block/genhd.c b/block/genhd.c
index 2f7feda61e35..d84a7df1e2a0 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -181,6 +181,12 @@ void disk_part_iter_exit(struct disk_part_iter *piter)
}
EXPORT_SYMBOL_GPL(disk_part_iter_exit);
+static inline int sector_in_part(struct hd_struct *part, sector_t sector)
+{
+ return part->start_sect <= sector &&
+ sector < part->start_sect + part->nr_sects;
+}
+
/**
* disk_map_sector_rcu - map sector to partition
* @disk: gendisk of interest
@@ -199,16 +205,22 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit);
struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
{
struct disk_part_tbl *ptbl;
+ struct hd_struct *part;
int i;
ptbl = rcu_dereference(disk->part_tbl);
+ part = rcu_dereference(ptbl->last_lookup);
+ if (part && sector_in_part(part, sector))
+ return part;
+
for (i = 1; i < ptbl->len; i++) {
- struct hd_struct *part = rcu_dereference(ptbl->part[i]);
+ part = rcu_dereference(ptbl->part[i]);
- if (part && part->start_sect <= sector &&
- sector < part->start_sect + part->nr_sects)
+ if (part && sector_in_part(part, sector)) {
+ rcu_assign_pointer(ptbl->last_lookup, part);
return part;
+ }
}
return &disk->part0;
}
@@ -888,8 +900,11 @@ static void disk_replace_part_tbl(struct gendisk *disk,
struct disk_part_tbl *old_ptbl = disk->part_tbl;
rcu_assign_pointer(disk->part_tbl, new_ptbl);
- if (old_ptbl)
+
+ if (old_ptbl) {
+ rcu_assign_pointer(old_ptbl->last_lookup, NULL);
call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb);
+ }
}
/**