diff options
| author | Keith Busch <keith.busch@intel.com> | 2014-08-26 09:05:36 -0600 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-11-05 20:27:40 +0000 |
| commit | a288cafeceb6e18ba4fd10ec8d3270593472cca6 (patch) | |
| tree | 3ec11e6f9758e5620b7d4f8ad55bc77ba9dd8083 /block/genhd.c | |
| parent | 1cc8e21690688b24b0b9388dbb14e1d2cf4f94b4 (diff) | |
block: Fix dev_t minor allocation lifetime
commit 2da78092dda13f1efd26edbbf99a567776913750 upstream.
Releases the dev_t minor when all references are closed to prevent
another device from acquiring the same major/minor.
Since the partition's release may be invoked from call_rcu's soft-irq
context, the ext_dev_idr's mutex had to be replaced with a spinlock so
as not so sleep.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
[bwh: Backported to 3.2:
- Adjust filename
- idr insertion API is different, and blk_alloc_devt() is preallocating
a node in a different way]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'block/genhd.c')
| -rw-r--r-- | block/genhd.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/block/genhd.c b/block/genhd.c index 8bd4ef247da3..35415810da84 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -28,10 +28,10 @@ struct kobject *block_depr; /* for extended dynamic devt allocation, currently only one major is used */ #define NR_EXT_DEVT (1 << MINORBITS) -/* For extended devt allocation. ext_devt_mutex prevents look up +/* For extended devt allocation. ext_devt_lock prevents look up * results from going away underneath its user. */ -static DEFINE_MUTEX(ext_devt_mutex); +static DEFINE_SPINLOCK(ext_devt_lock); static DEFINE_IDR(ext_devt_idr); static struct device_type disk_type; @@ -421,13 +421,13 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt) do { if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL)) return -ENOMEM; - mutex_lock(&ext_devt_mutex); + spin_lock(&ext_devt_lock); rc = idr_get_new(&ext_devt_idr, part, &idx); if (!rc && idx >= NR_EXT_DEVT) { idr_remove(&ext_devt_idr, idx); rc = -EBUSY; } - mutex_unlock(&ext_devt_mutex); + spin_unlock(&ext_devt_lock); } while (rc == -EAGAIN); if (rc) @@ -454,9 +454,9 @@ void blk_free_devt(dev_t devt) return; if (MAJOR(devt) == BLOCK_EXT_MAJOR) { - mutex_lock(&ext_devt_mutex); + spin_lock(&ext_devt_lock); idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); - mutex_unlock(&ext_devt_mutex); + spin_unlock(&ext_devt_lock); } } @@ -663,7 +663,6 @@ void del_gendisk(struct gendisk *disk) if (!sysfs_deprecated) sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); device_del(disk_to_dev(disk)); - blk_free_devt(disk_to_dev(disk)->devt); } EXPORT_SYMBOL(del_gendisk); @@ -688,13 +687,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno) } else { struct hd_struct *part; - mutex_lock(&ext_devt_mutex); + spin_lock(&ext_devt_lock); part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); if (part && get_disk(part_to_disk(part))) { *partno = part->partno; disk = part_to_disk(part); } - mutex_unlock(&ext_devt_mutex); + spin_unlock(&ext_devt_lock); } return disk; @@ -1102,6 +1101,7 @@ static void disk_release(struct device *dev) { struct gendisk *disk = dev_to_disk(dev); + blk_free_devt(dev->devt); disk_release_events(disk); kfree(disk->random); disk_replace_part_tbl(disk, NULL); |