* [PATCH] block: protect rw_page against device teardown
@ 2015-11-20 0:14 Dan Williams
2015-11-20 0:32 ` kbuild test robot
0 siblings, 1 reply; 5+ messages in thread
From: Dan Williams @ 2015-11-20 0:14 UTC (permalink / raw)
To: axboe
Cc: linux-nvdimm, linux-kernel, stable, linux-block, Alexander Viro,
Matthew Wilcox
Fix use after free crashes like the following:
general protection fault: 0000 [#1] SMP
Call Trace:
[<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
[<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
[<ffffffff8128fd90>] bdev_read_page+0x50/0x60
[<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
[<ffffffff81297657>] mpage_readpages+0x107/0x170
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
[<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
[<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
[<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
[<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
[<ffffffff811c76f6>] filemap_fault+0x396/0x530
[<ffffffff811f816e>] __do_fault+0x4e/0xf0
[<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50
Cc: <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
fs/block_dev.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bb0dfb1c7af1..cc0af12acf94 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -390,9 +390,17 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
struct page *page)
{
const struct block_device_operations *ops = bdev->bd_disk->fops;
+ int rc = -EOPNOTSUPP;
+
if (!ops->rw_page || bdev_get_integrity(bdev))
- return -EOPNOTSUPP;
- return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ return rc;
+
+ rc = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (rc)
+ return rc;
+ rc = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ blk_queue_exit(bdev->bd_queue);
+ return rc;
}
EXPORT_SYMBOL_GPL(bdev_read_page);
@@ -421,14 +429,20 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
int result;
int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
const struct block_device_operations *ops = bdev->bd_disk->fops;
+
if (!ops->rw_page || bdev_get_integrity(bdev))
return -EOPNOTSUPP;
+ result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (result)
+ return result;
+
set_page_writeback(page);
result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
if (result)
end_page_writeback(page);
else
unlock_page(page);
+ blk_queue_exit(bdev->bd_queue);
return result;
}
EXPORT_SYMBOL_GPL(bdev_write_page);
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] block: protect rw_page against device teardown
2015-11-20 0:14 [PATCH] block: protect rw_page against device teardown Dan Williams
@ 2015-11-20 0:32 ` kbuild test robot
2015-11-20 0:51 ` Williams, Dan J
0 siblings, 1 reply; 5+ messages in thread
From: kbuild test robot @ 2015-11-20 0:32 UTC (permalink / raw)
To: Dan Williams
Cc: kbuild-all, axboe, linux-nvdimm, linux-kernel, stable,
linux-block, Alexander Viro, Matthew Wilcox
[-- Attachment #1: Type: text/plain, Size: 1785 bytes --]
Hi Dan,
[auto build test ERROR on: block/for-next]
[also build test ERROR on: v4.4-rc1 next-20151119]
url: https://github.com/0day-ci/linux/commits/Dan-Williams/block-protect-rw_page-against-device-teardown/20151120-081807
base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
config: xtensa-common_defconfig (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa
All errors (new ones prefixed by >>):
fs/block_dev.c: In function 'bdev_read_page':
>> fs/block_dev.c:389:2: error: implicit declaration of function 'blk_queue_enter' [-Werror=implicit-function-declaration]
rc = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
^
>> fs/block_dev.c:393:2: error: implicit declaration of function 'blk_queue_exit' [-Werror=implicit-function-declaration]
blk_queue_exit(bdev->bd_queue);
^
cc1: some warnings being treated as errors
vim +/blk_queue_enter +389 fs/block_dev.c
383 const struct block_device_operations *ops = bdev->bd_disk->fops;
384 int rc = -EOPNOTSUPP;
385
386 if (!ops->rw_page || bdev_get_integrity(bdev))
387 return rc;
388
> 389 rc = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
390 if (rc)
391 return rc;
392 rc = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
> 393 blk_queue_exit(bdev->bd_queue);
394 return rc;
395 }
396 EXPORT_SYMBOL_GPL(bdev_read_page);
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 9576 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] block: protect rw_page against device teardown
2015-11-20 0:32 ` kbuild test robot
@ 2015-11-20 0:51 ` Williams, Dan J
2015-11-20 18:12 ` Matthew Wilcox
0 siblings, 1 reply; 5+ messages in thread
From: Williams, Dan J @ 2015-11-20 0:51 UTC (permalink / raw)
To: axboe
Cc: linux-kernel, linux-nvdimm@lists.01.org, linux-block, stable,
willy, viro
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 4712 bytes --]
On Fri, 2015-11-20 at 08:32 +0800, kbuild test robot wrote:
> Hi Dan,
>
> [auto build test ERROR on: block/for-next]
> [also build test ERROR on: v4.4-rc1 next-20151119]
Thanks kbuild robot! ;-)
I indeed had rebased this in my tree in front of another patch that
made blk_queue_enter() public. Â Given that other patch is 4.5 material,
move that declaration change into this patch:
8<----
Subject: block: protect rw_page against device teardown
From: Dan Williams <dan.j.williams@intel.com>
Fix use after free crashes like the following:
 general protection fault: 0000 [#1] SMP
 Call Trace:
 [<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
 [<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
 [<ffffffff8128fd90>] bdev_read_page+0x50/0x60
 [<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
 [<ffffffff81297657>] mpage_readpages+0x107/0x170
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
 [<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
 [<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
 [<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
 [<ffffffff811c76f6>] filemap_fault+0x396/0x530
 [<ffffffff811f816e>] __do_fault+0x4e/0xf0
 [<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50
Cc: <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 block/blk.h            |    2 --
 fs/block_dev.c         |   18 ++++++++++++++++--
 include/linux/blkdev.h |    2 ++
 3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/block/blk.h b/block/blk.h
index da722eb786df..c43926d3d74d 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -72,8 +72,6 @@ void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 bool __blk_end_bidi_request(struct request *rq, int error,
     unsigned int nr_bytes, unsigned int bidi_bytes);
-int blk_queue_enter(struct request_queue *q, gfp_t gfp);
-void blk_queue_exit(struct request_queue *q);
 void blk_freeze_queue(struct request_queue *q);
Â
 static inline void blk_queue_enter_live(struct request_queue *q)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bb0dfb1c7af1..cc0af12acf94 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -390,9 +390,17 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
 struct page *page)
 {
 const struct block_device_operations *ops = bdev->bd_disk->fops;
+ int rc = -EOPNOTSUPP;
+
 if (!ops->rw_page || bdev_get_integrity(bdev))
- return -EOPNOTSUPP;
- return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ return rc;
+
+ rc = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (rc)
+ return rc;
+ rc = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ blk_queue_exit(bdev->bd_queue);
+ return rc;
 }
 EXPORT_SYMBOL_GPL(bdev_read_page);
Â
@@ -421,14 +429,20 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 int result;
 int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
 const struct block_device_operations *ops = bdev->bd_disk->fops;
+
 if (!ops->rw_page || bdev_get_integrity(bdev))
 return -EOPNOTSUPP;
+ result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (result)
+ return result;
+
 set_page_writeback(page);
 result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
 if (result)
 end_page_writeback(page);
 else
 unlock_page(page);
+ blk_queue_exit(bdev->bd_queue);
 return result;
 }
 EXPORT_SYMBOL_GPL(bdev_write_page);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3fe27f8d91f0..c0d2b7927c1f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -794,6 +794,8 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
  struct scsi_ioctl_command __user *);
Â
+extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
+extern void blk_queue_exit(struct request_queue *q);
 extern void blk_start_queue(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] block: protect rw_page against device teardown
2015-11-20 0:51 ` Williams, Dan J
@ 2015-11-20 18:12 ` Matthew Wilcox
2015-11-20 18:26 ` Williams, Dan J
0 siblings, 1 reply; 5+ messages in thread
From: Matthew Wilcox @ 2015-11-20 18:12 UTC (permalink / raw)
To: Williams, Dan J
Cc: axboe, linux-kernel, linux-nvdimm@lists.01.org, linux-block,
stable, viro
I'd prefer bdev_read_page() and bdev_write_page() to be a bit more consistent
(eg 'rc' vs 'result'), but:
Acked-by: Matthew Wilcox <willy@linux.intel.com>
On Fri, Nov 20, 2015 at 12:51:30AM +0000, Williams, Dan J wrote:
> On Fri, 2015-11-20 at 08:32 +0800, kbuild test robot wrote:
> > Hi Dan,
> >
> > [auto build test ERROR on: block/for-next]
> > [also build test ERROR on: v4.4-rc1 next-20151119]
>
> Thanks kbuild robot! ;-)
>
> I indeed had rebased this in my tree in front of another patch that
> made blk_queue_enter() public. Given that other patch is 4.5 material,
> move that declaration change into this patch:
>
> 8<----
> Subject: block: protect rw_page against device teardown
>
> From: Dan Williams <dan.j.williams@intel.com>
>
> Fix use after free crashes like the following:
>
> general protection fault: 0000 [#1] SMP
> Call Trace:
> [<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
> [<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
> [<ffffffff8128fd90>] bdev_read_page+0x50/0x60
> [<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
> [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
> [<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
> [<ffffffff81297657>] mpage_readpages+0x107/0x170
> [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
> [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
> [<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
> [<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
> [<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
> [<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
> [<ffffffff811c76f6>] filemap_fault+0x396/0x530
> [<ffffffff811f816e>] __do_fault+0x4e/0xf0
> [<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50
>
> Cc: <stable@vger.kernel.org>
> Cc: Jens Axboe <axboe@fb.com>
> Cc: Matthew Wilcox <willy@linux.intel.com>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
> block/blk.h | 2 --
> fs/block_dev.c | 18 ++++++++++++++++--
> include/linux/blkdev.h | 2 ++
> 3 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/block/blk.h b/block/blk.h
> index da722eb786df..c43926d3d74d 100644
> --- a/block/blk.h
> +++ b/block/blk.h
> @@ -72,8 +72,6 @@ void blk_dequeue_request(struct request *rq);
> void __blk_queue_free_tags(struct request_queue *q);
> bool __blk_end_bidi_request(struct request *rq, int error,
> unsigned int nr_bytes, unsigned int bidi_bytes);
> -int blk_queue_enter(struct request_queue *q, gfp_t gfp);
> -void blk_queue_exit(struct request_queue *q);
> void blk_freeze_queue(struct request_queue *q);
>
> static inline void blk_queue_enter_live(struct request_queue *q)
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index bb0dfb1c7af1..cc0af12acf94 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -390,9 +390,17 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
> struct page *page)
> {
> const struct block_device_operations *ops = bdev->bd_disk->fops;
> + int rc = -EOPNOTSUPP;
> +
> if (!ops->rw_page || bdev_get_integrity(bdev))
> - return -EOPNOTSUPP;
> - return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
> + return rc;
> +
> + rc = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
> + if (rc)
> + return rc;
> + rc = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
> + blk_queue_exit(bdev->bd_queue);
> + return rc;
> }
> EXPORT_SYMBOL_GPL(bdev_read_page);
>
> @@ -421,14 +429,20 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
> int result;
> int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
> const struct block_device_operations *ops = bdev->bd_disk->fops;
> +
> if (!ops->rw_page || bdev_get_integrity(bdev))
> return -EOPNOTSUPP;
> + result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
> + if (result)
> + return result;
> +
> set_page_writeback(page);
> result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
> if (result)
> end_page_writeback(page);
> else
> unlock_page(page);
> + blk_queue_exit(bdev->bd_queue);
> return result;
> }
> EXPORT_SYMBOL_GPL(bdev_write_page);
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 3fe27f8d91f0..c0d2b7927c1f 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -794,6 +794,8 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
> extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
> struct scsi_ioctl_command __user *);
>
> +extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
> +extern void blk_queue_exit(struct request_queue *q);
> extern void blk_start_queue(struct request_queue *q);
> extern void blk_stop_queue(struct request_queue *q);
> extern void blk_sync_queue(struct request_queue *q);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] block: protect rw_page against device teardown
2015-11-20 18:12 ` Matthew Wilcox
@ 2015-11-20 18:26 ` Williams, Dan J
0 siblings, 0 replies; 5+ messages in thread
From: Williams, Dan J @ 2015-11-20 18:26 UTC (permalink / raw)
To: willy
Cc: linux-kernel, linux-nvdimm@lists.01.org, linux-block, stable,
axboe, viro
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 4638 bytes --]
On Fri, 2015-11-20 at 13:12 -0500, Matthew Wilcox wrote:
> I'd prefer bdev_read_page() and bdev_write_page() to be a bit more
> consistent
> (eg 'rc' vs 'result'), but:
>
> Acked-by: Matthew Wilcox <willy@linux.intel.com>
Thanks! Â Fixed up version:
8<----
Subject: block: protect rw_page against device teardown
From: Dan Williams <dan.j.williams@intel.com>
Fix use after free crashes like the following:
 general protection fault: 0000 [#1] SMP
 Call Trace:
 [<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
 [<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
 [<ffffffff8128fd90>] bdev_read_page+0x50/0x60
 [<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
 [<ffffffff81297657>] mpage_readpages+0x107/0x170
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
 [<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
 [<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
 [<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
 [<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
 [<ffffffff811c76f6>] filemap_fault+0x396/0x530
 [<ffffffff811f816e>] __do_fault+0x4e/0xf0
 [<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50
Cc: <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
[willy: symmetry fixups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 block/blk.h            |    2 --
 fs/block_dev.c         |   18 ++++++++++++++++--
 include/linux/blkdev.h |    2 ++
 3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/block/blk.h b/block/blk.h
index da722eb786df..c43926d3d74d 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -72,8 +72,6 @@ void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 bool __blk_end_bidi_request(struct request *rq, int error,
     unsigned int nr_bytes, unsigned int bidi_bytes);
-int blk_queue_enter(struct request_queue *q, gfp_t gfp);
-void blk_queue_exit(struct request_queue *q);
 void blk_freeze_queue(struct request_queue *q);
Â
 static inline void blk_queue_enter_live(struct request_queue *q)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index bb0dfb1c7af1..c25639e907bd 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -390,9 +390,17 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
 struct page *page)
 {
 const struct block_device_operations *ops = bdev->bd_disk->fops;
+ int result = -EOPNOTSUPP;
+
 if (!ops->rw_page || bdev_get_integrity(bdev))
- return -EOPNOTSUPP;
- return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ return result;
+
+ result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (result)
+ return result;
+ result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+ blk_queue_exit(bdev->bd_queue);
+ return result;
 }
 EXPORT_SYMBOL_GPL(bdev_read_page);
Â
@@ -421,14 +429,20 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 int result;
 int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
 const struct block_device_operations *ops = bdev->bd_disk->fops;
+
 if (!ops->rw_page || bdev_get_integrity(bdev))
 return -EOPNOTSUPP;
+ result = blk_queue_enter(bdev->bd_queue, GFP_KERNEL);
+ if (result)
+ return result;
+
 set_page_writeback(page);
 result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
 if (result)
 end_page_writeback(page);
 else
 unlock_page(page);
+ blk_queue_exit(bdev->bd_queue);
 return result;
 }
 EXPORT_SYMBOL_GPL(bdev_write_page);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3fe27f8d91f0..c0d2b7927c1f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -794,6 +794,8 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
  struct scsi_ioctl_command __user *);
Â
+extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
+extern void blk_queue_exit(struct request_queue *q);
 extern void blk_start_queue(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-11-20 18:26 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-11-20 0:14 [PATCH] block: protect rw_page against device teardown Dan Williams
2015-11-20 0:32 ` kbuild test robot
2015-11-20 0:51 ` Williams, Dan J
2015-11-20 18:12 ` Matthew Wilcox
2015-11-20 18:26 ` Williams, Dan J
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