diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-08-07 12:25:34 -0400 |
---|---|---|
committer | Jens Axboe <jaxboe@fusionio.com> | 2010-08-07 12:25:34 -0400 |
commit | 6e9624b8caec290d28b4c6d9ec75749df6372b87 (patch) | |
tree | 47225b544e1da82742795553dc4e8aa70c17afdc /drivers/s390/block | |
parent | 8a6cfeb6deca3a8fefd639d898b0d163c0b5d368 (diff) |
block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.
This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.
The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.
Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'drivers/s390/block')
-rw-r--r-- | drivers/s390/block/dasd.c | 6 | ||||
-rw-r--r-- | drivers/s390/block/dcssblk.c | 5 |
2 files changed, 11 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 17b033d0e050..1a84fae155e1 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c | |||
@@ -21,6 +21,7 @@ | |||
21 | #include <linux/hdreg.h> | 21 | #include <linux/hdreg.h> |
22 | #include <linux/async.h> | 22 | #include <linux/async.h> |
23 | #include <linux/mutex.h> | 23 | #include <linux/mutex.h> |
24 | #include <linux/smp_lock.h> | ||
24 | 25 | ||
25 | #include <asm/ccwdev.h> | 26 | #include <asm/ccwdev.h> |
26 | #include <asm/ebcdic.h> | 27 | #include <asm/ebcdic.h> |
@@ -2235,6 +2236,7 @@ static int dasd_open(struct block_device *bdev, fmode_t mode) | |||
2235 | if (!block) | 2236 | if (!block) |
2236 | return -ENODEV; | 2237 | return -ENODEV; |
2237 | 2238 | ||
2239 | lock_kernel(); | ||
2238 | base = block->base; | 2240 | base = block->base; |
2239 | atomic_inc(&block->open_count); | 2241 | atomic_inc(&block->open_count); |
2240 | if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) { | 2242 | if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) { |
@@ -2269,12 +2271,14 @@ static int dasd_open(struct block_device *bdev, fmode_t mode) | |||
2269 | goto out; | 2271 | goto out; |
2270 | } | 2272 | } |
2271 | 2273 | ||
2274 | unlock_kernel(); | ||
2272 | return 0; | 2275 | return 0; |
2273 | 2276 | ||
2274 | out: | 2277 | out: |
2275 | module_put(base->discipline->owner); | 2278 | module_put(base->discipline->owner); |
2276 | unlock: | 2279 | unlock: |
2277 | atomic_dec(&block->open_count); | 2280 | atomic_dec(&block->open_count); |
2281 | unlock_kernel(); | ||
2278 | return rc; | 2282 | return rc; |
2279 | } | 2283 | } |
2280 | 2284 | ||
@@ -2282,8 +2286,10 @@ static int dasd_release(struct gendisk *disk, fmode_t mode) | |||
2282 | { | 2286 | { |
2283 | struct dasd_block *block = disk->private_data; | 2287 | struct dasd_block *block = disk->private_data; |
2284 | 2288 | ||
2289 | lock_kernel(); | ||
2285 | atomic_dec(&block->open_count); | 2290 | atomic_dec(&block->open_count); |
2286 | module_put(block->base->discipline->owner); | 2291 | module_put(block->base->discipline->owner); |
2292 | unlock_kernel(); | ||
2287 | return 0; | 2293 | return 0; |
2288 | } | 2294 | } |
2289 | 2295 | ||
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 9b43ae94beba..2bd72aa34c59 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c | |||
@@ -14,6 +14,7 @@ | |||
14 | #include <linux/init.h> | 14 | #include <linux/init.h> |
15 | #include <linux/slab.h> | 15 | #include <linux/slab.h> |
16 | #include <linux/blkdev.h> | 16 | #include <linux/blkdev.h> |
17 | #include <linux/smp_lock.h> | ||
17 | #include <linux/completion.h> | 18 | #include <linux/completion.h> |
18 | #include <linux/interrupt.h> | 19 | #include <linux/interrupt.h> |
19 | #include <linux/platform_device.h> | 20 | #include <linux/platform_device.h> |
@@ -775,6 +776,7 @@ dcssblk_open(struct block_device *bdev, fmode_t mode) | |||
775 | struct dcssblk_dev_info *dev_info; | 776 | struct dcssblk_dev_info *dev_info; |
776 | int rc; | 777 | int rc; |
777 | 778 | ||
779 | lock_kernel(); | ||
778 | dev_info = bdev->bd_disk->private_data; | 780 | dev_info = bdev->bd_disk->private_data; |
779 | if (NULL == dev_info) { | 781 | if (NULL == dev_info) { |
780 | rc = -ENODEV; | 782 | rc = -ENODEV; |
@@ -784,6 +786,7 @@ dcssblk_open(struct block_device *bdev, fmode_t mode) | |||
784 | bdev->bd_block_size = 4096; | 786 | bdev->bd_block_size = 4096; |
785 | rc = 0; | 787 | rc = 0; |
786 | out: | 788 | out: |
789 | unlock_kernel(); | ||
787 | return rc; | 790 | return rc; |
788 | } | 791 | } |
789 | 792 | ||
@@ -794,6 +797,7 @@ dcssblk_release(struct gendisk *disk, fmode_t mode) | |||
794 | struct segment_info *entry; | 797 | struct segment_info *entry; |
795 | int rc; | 798 | int rc; |
796 | 799 | ||
800 | lock_kernel(); | ||
797 | if (!dev_info) { | 801 | if (!dev_info) { |
798 | rc = -ENODEV; | 802 | rc = -ENODEV; |
799 | goto out; | 803 | goto out; |
@@ -811,6 +815,7 @@ dcssblk_release(struct gendisk *disk, fmode_t mode) | |||
811 | up_write(&dcssblk_devices_sem); | 815 | up_write(&dcssblk_devices_sem); |
812 | rc = 0; | 816 | rc = 0; |
813 | out: | 817 | out: |
818 | unlock_kernel(); | ||
814 | return rc; | 819 | return rc; |
815 | } | 820 | } |
816 | 821 | ||