* [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.  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);ÿôèº{.nÇ+‰·Ÿ®‰†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a¢f£¢·hšïêÿ‘êçz_è®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨èÚ&£ø§~á¶iO•æ¬z·švØ^\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!  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);   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);  @@ -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);ÿôèº{.nÇ+‰·Ÿ®‰†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a¢f£¢·hšïêÿ‘êçz_è®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨èÚ&£ø§~á¶iO•æ¬z·švØ^\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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