<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux/fs/block_dev.c, branch v5.8</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
</subtitle>
<id>https://git.shady.money/linux/atom?h=v5.8</id>
<link rel='self' href='https://git.shady.money/linux/atom?h=v5.8'/>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/'/>
<updated>2020-06-18T15:24:35Z</updated>
<entry>
<title>block: make function 'kill_bdev' static</title>
<updated>2020-06-18T15:24:35Z</updated>
<author>
<name>Zheng Bin</name>
<email>zhengbin13@huawei.com</email>
</author>
<published>2020-06-18T04:21:38Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=3373a3461aa15b7f9a871fa4cb2c9ef21ac20b47'/>
<id>urn:sha1:3373a3461aa15b7f9a871fa4cb2c9ef21ac20b47</id>
<content type='text'>
kill_bdev does not have any external user, so make it static.

Signed-off-by: Zheng Bin &lt;zhengbin13@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>block: Fix use-after-free in blkdev_get()</title>
<updated>2020-06-16T16:33:12Z</updated>
<author>
<name>Jason Yan</name>
<email>yanaijie@huawei.com</email>
</author>
<published>2020-06-16T12:16:55Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=2d3a8e2deddea6c89961c422ec0c5b851e648c14'/>
<id>urn:sha1:2d3a8e2deddea6c89961c422ec0c5b851e648c14</id>
<content type='text'>
In blkdev_get() we call __blkdev_get() to do some internal jobs and if
there is some errors in __blkdev_get(), the bdput() is called which
means we have released the refcount of the bdev (actually the refcount of
the bdev inode). This means we cannot access bdev after that point. But
acctually bdev is still accessed in blkdev_get() after calling
__blkdev_get(). This results in use-after-free if the refcount is the
last one we released in __blkdev_get(). Let's take a look at the
following scenerio:

  CPU0            CPU1                    CPU2
blkdev_open     blkdev_open           Remove disk
                  bd_acquire
		  blkdev_get
		    __blkdev_get      del_gendisk
					bdev_unhash_inode
  bd_acquire          bdev_get_gendisk
    bd_forget           failed because of unhashed
	  bdput
	              bdput (the last one)
		        bdev_evict_inode

	  	    access bdev =&gt; use after free

[  459.350216] BUG: KASAN: use-after-free in __lock_acquire+0x24c1/0x31b0
[  459.351190] Read of size 8 at addr ffff88806c815a80 by task syz-executor.0/20132
[  459.352347]
[  459.352594] CPU: 0 PID: 20132 Comm: syz-executor.0 Not tainted 4.19.90 #2
[  459.353628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  459.354947] Call Trace:
[  459.355337]  dump_stack+0x111/0x19e
[  459.355879]  ? __lock_acquire+0x24c1/0x31b0
[  459.356523]  print_address_description+0x60/0x223
[  459.357248]  ? __lock_acquire+0x24c1/0x31b0
[  459.357887]  kasan_report.cold+0xae/0x2d8
[  459.358503]  __lock_acquire+0x24c1/0x31b0
[  459.359120]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.359784]  ? lockdep_hardirqs_on+0x37b/0x580
[  459.360465]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.361123]  ? finish_task_switch+0x125/0x600
[  459.361812]  ? finish_task_switch+0xee/0x600
[  459.362471]  ? mark_held_locks+0xf0/0xf0
[  459.363108]  ? __schedule+0x96f/0x21d0
[  459.363716]  lock_acquire+0x111/0x320
[  459.364285]  ? blkdev_get+0xce/0xbe0
[  459.364846]  ? blkdev_get+0xce/0xbe0
[  459.365390]  __mutex_lock+0xf9/0x12a0
[  459.365948]  ? blkdev_get+0xce/0xbe0
[  459.366493]  ? bdev_evict_inode+0x1f0/0x1f0
[  459.367130]  ? blkdev_get+0xce/0xbe0
[  459.367678]  ? destroy_inode+0xbc/0x110
[  459.368261]  ? mutex_trylock+0x1a0/0x1a0
[  459.368867]  ? __blkdev_get+0x3e6/0x1280
[  459.369463]  ? bdev_disk_changed+0x1d0/0x1d0
[  459.370114]  ? blkdev_get+0xce/0xbe0
[  459.370656]  blkdev_get+0xce/0xbe0
[  459.371178]  ? find_held_lock+0x2c/0x110
[  459.371774]  ? __blkdev_get+0x1280/0x1280
[  459.372383]  ? lock_downgrade+0x680/0x680
[  459.373002]  ? lock_acquire+0x111/0x320
[  459.373587]  ? bd_acquire+0x21/0x2c0
[  459.374134]  ? do_raw_spin_unlock+0x4f/0x250
[  459.374780]  blkdev_open+0x202/0x290
[  459.375325]  do_dentry_open+0x49e/0x1050
[  459.375924]  ? blkdev_get_by_dev+0x70/0x70
[  459.376543]  ? __x64_sys_fchdir+0x1f0/0x1f0
[  459.377192]  ? inode_permission+0xbe/0x3a0
[  459.377818]  path_openat+0x148c/0x3f50
[  459.378392]  ? kmem_cache_alloc+0xd5/0x280
[  459.379016]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.379802]  ? path_lookupat.isra.0+0x900/0x900
[  459.380489]  ? __lock_is_held+0xad/0x140
[  459.381093]  do_filp_open+0x1a1/0x280
[  459.381654]  ? may_open_dev+0xf0/0xf0
[  459.382214]  ? find_held_lock+0x2c/0x110
[  459.382816]  ? lock_downgrade+0x680/0x680
[  459.383425]  ? __lock_is_held+0xad/0x140
[  459.384024]  ? do_raw_spin_unlock+0x4f/0x250
[  459.384668]  ? _raw_spin_unlock+0x1f/0x30
[  459.385280]  ? __alloc_fd+0x448/0x560
[  459.385841]  do_sys_open+0x3c3/0x500
[  459.386386]  ? filp_open+0x70/0x70
[  459.386911]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  459.387610]  ? trace_hardirqs_off_caller+0x55/0x1c0
[  459.388342]  ? do_syscall_64+0x1a/0x520
[  459.388930]  do_syscall_64+0xc3/0x520
[  459.389490]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.390248] RIP: 0033:0x416211
[  459.390720] Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83
04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f
   05 &lt;48&gt; 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d
      01
[  459.393483] RSP: 002b:00007fe45dfe9a60 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
[  459.394610] RAX: ffffffffffffffda RBX: 00007fe45dfea6d4 RCX: 0000000000416211
[  459.395678] RDX: 00007fe45dfe9b0a RSI: 0000000000000002 RDI: 00007fe45dfe9b00
[  459.396758] RBP: 000000000076bf20 R08: 0000000000000000 R09: 000000000000000a
[  459.397930] R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff
[  459.399022] R13: 0000000000000bd9 R14: 00000000004cdb80 R15: 000000000076bf2c
[  459.400168]
[  459.400430] Allocated by task 20132:
[  459.401038]  kasan_kmalloc+0xbf/0xe0
[  459.401652]  kmem_cache_alloc+0xd5/0x280
[  459.402330]  bdev_alloc_inode+0x18/0x40
[  459.402970]  alloc_inode+0x5f/0x180
[  459.403510]  iget5_locked+0x57/0xd0
[  459.404095]  bdget+0x94/0x4e0
[  459.404607]  bd_acquire+0xfa/0x2c0
[  459.405113]  blkdev_open+0x110/0x290
[  459.405702]  do_dentry_open+0x49e/0x1050
[  459.406340]  path_openat+0x148c/0x3f50
[  459.406926]  do_filp_open+0x1a1/0x280
[  459.407471]  do_sys_open+0x3c3/0x500
[  459.408010]  do_syscall_64+0xc3/0x520
[  459.408572]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.409415]
[  459.409679] Freed by task 1262:
[  459.410212]  __kasan_slab_free+0x129/0x170
[  459.410919]  kmem_cache_free+0xb2/0x2a0
[  459.411564]  rcu_process_callbacks+0xbb2/0x2320
[  459.412318]  __do_softirq+0x225/0x8ac

Fix this by delaying bdput() to the end of blkdev_get() which means we
have finished accessing bdev.

Fixes: 77ea887e433a ("implement in-kernel gendisk events handling")
Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Signed-off-by: Jason Yan &lt;yanaijie@huawei.com&gt;
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block</title>
<updated>2020-06-02T22:37:03Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-06-02T22:37:03Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=bce159d734091fe31340976081577333f52a85e4'/>
<id>urn:sha1:bce159d734091fe31340976081577333f52a85e4</id>
<content type='text'>
Pull block driver updates from Jens Axboe:
 "On top of the core changes, here are the block driver changes for this
  merge window:

   - NVMe changes:
        - NVMe over Fibre Channel protocol updates, which also reach
          over to drivers/scsi/lpfc (James Smart)
        - namespace revalidation support on the target (Anthony
          Iliopoulos)
        - gcc zero length array fix (Arnd Bergmann)
        - nvmet cleanups (Chaitanya Kulkarni)
        - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg)
        - use a SRQ per completion vector (Max Gurtovoy)
        - fix handling of runtime changes to the queue count (Weiping
          Zhang)
        - t10 protection information support for nvme-rdma and
          nvmet-rdma (Israel Rukshin and Max Gurtovoy)
        - target side AEN improvements (Chaitanya Kulkarni)
        - various fixes and minor improvements all over, icluding the
          nvme part of the lpfc driver"

   - Floppy code cleanup series (Willy, Denis)

   - Floppy contention fix (Jiri)

   - Loop CONFIGURE support (Martijn)

   - bcache fixes/improvements (Coly, Joe, Colin)

   - q-&gt;queuedata cleanups (Christoph)

   - Get rid of ioctl_by_bdev (Christoph, Stefan)

   - md/raid5 allocation fixes (Coly)

   - zero length array fixes (Gustavo)

   - swim3 task state fix (Xu)"

* tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits)
  bcache: configure the asynchronous registertion to be experimental
  bcache: asynchronous devices registration
  bcache: fix refcount underflow in bcache_device_free()
  bcache: Convert pr_&lt;level&gt; uses to a more typical style
  bcache: remove redundant variables i and n
  lpfc: Fix return value in __lpfc_nvme_ls_abort
  lpfc: fix axchg pointer reference after free and double frees
  lpfc: Fix pointer checks and comments in LS receive refactoring
  nvme: set dma alignment to qword
  nvmet: cleanups the loop in nvmet_async_events_process
  nvmet: fix memory leak when removing namespaces and controllers concurrently
  nvmet-rdma: add metadata/T10-PI support
  nvmet: add metadata support for block devices
  nvmet: add metadata/T10-PI support
  nvme: add Metadata Capabilities enumerations
  nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len
  nvmet: rename nvmet_rw_len to nvmet_rw_data_len
  nvmet: add metadata characteristics for a namespace
  nvme-rdma: add metadata/T10-PI support
  nvme-rdma: introduce nvme_rdma_sgl structure
  ...
</content>
</entry>
<entry>
<title>Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block</title>
<updated>2020-06-02T22:29:19Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-06-02T22:29:19Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=750a02ab8d3c49ca7d23102be90d3d1db19e2827'/>
<id>urn:sha1:750a02ab8d3c49ca7d23102be90d3d1db19e2827</id>
<content type='text'>
Pull block updates from Jens Axboe:
 "Core block changes that have been queued up for this release:

   - Remove dead blk-throttle and blk-wbt code (Guoqing)

   - Include pid in blktrace note traces (Jan)

   - Don't spew I/O errors on wouldblock termination (me)

   - Zone append addition (Johannes, Keith, Damien)

   - IO accounting improvements (Konstantin, Christoph)

   - blk-mq hardware map update improvements (Ming)

   - Scheduler dispatch improvement (Salman)

   - Inline block encryption support (Satya)

   - Request map fixes and improvements (Weiping)

   - blk-iocost tweaks (Tejun)

   - Fix for timeout failing with error injection (Keith)

   - Queue re-run fixes (Douglas)

   - CPU hotplug improvements (Christoph)

   - Queue entry/exit improvements (Christoph)

   - Move DMA drain handling to the few drivers that use it (Christoph)

   - Partition handling cleanups (Christoph)"

* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
  block: mark bio_wouldblock_error() bio with BIO_QUIET
  blk-wbt: rename __wbt_update_limits to wbt_update_limits
  blk-wbt: remove wbt_update_limits
  blk-throttle: remove tg_drain_bios
  blk-throttle: remove blk_throtl_drain
  null_blk: force complete for timeout request
  blk-mq: drain I/O when all CPUs in a hctx are offline
  blk-mq: add blk_mq_all_tag_iter
  blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
  blk-mq: use BLK_MQ_NO_TAG in more places
  blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
  blk-mq: move more request initialization to blk_mq_rq_ctx_init
  blk-mq: simplify the blk_mq_get_request calling convention
  blk-mq: remove the bio argument to -&gt;prepare_request
  nvme: force complete cancelled requests
  blk-mq: blk-mq: provide forced completion method
  block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
  block: blk-crypto-fallback: remove redundant initialization of variable err
  block: reduce part_stat_lock() scope
  block: use __this_cpu_add() instead of access by smp_processor_id()
  ...
</content>
</entry>
<entry>
<title>Merge tag 'pm-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2020-06-02T20:17:23Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-06-02T20:17:23Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=355ba37d756c38962fe9bb616f5f48eb12a7e11e'/>
<id>urn:sha1:355ba37d756c38962fe9bb616f5f48eb12a7e11e</id>
<content type='text'>
Pull power management updates from Rafael Wysocki:
 "These rework the system-wide PM driver flags, make runtime switching
  of cpuidle governors easier, improve the user space hibernation
  interface code, add intel-speed-select interface documentation, add
  more debug messages to the ACPI code handling suspend to idle, update
  the cpufreq core and drivers, fix a minor issue in the cpuidle core
  and update two cpuidle drivers, improve the PM-runtime framework,
  update the Intel RAPL power capping driver, update devfreq core and
  drivers, and clean up the cpupower utility.

  Specifics:

   - Rework the system-wide PM driver flags to make them easier to
     understand and use and update their documentation (Rafael Wysocki,
     Alan Stern).

   - Allow cpuidle governors to be switched at run time regardless of
     the kernel configuration and update the related documentation
     accordingly (Hanjun Guo).

   - Improve the resume device handling in the user space hibernarion
     interface code (Domenico Andreoli).

   - Document the intel-speed-select sysfs interface (Srinivas
     Pandruvada).

   - Make the ACPI code handing suspend to idle print more debug
     messages to help diagnose issues with it (Rafael Wysocki).

   - Fix a helper routine in the cpufreq core and correct a typo in the
     struct cpufreq_driver kerneldoc comment (Rafael Wysocki, Wang
     Wenhu).

   - Update cpufreq drivers:

      - Make the intel_pstate driver start in the passive mode by
        default on systems without HWP (Rafael Wysocki).

      - Add i.MX7ULP support to the imx-cpufreq-dt driver and add
        i.MX7ULP to the cpufreq-dt-platdev blacklist (Peng Fan).

      - Convert the qoriq cpufreq driver to a platform one, make the
        platform code create a suitable device object for it and add
        platform dependencies to it (Mian Yousaf Kaukab, Geert
        Uytterhoeven).

      - Fix wrong compatible binding in the qcom driver (Ansuel Smith).

      - Build the omap driver by default for ARCH_OMAP2PLUS (Anders
        Roxell).

      - Add r8a7742 SoC support to the dt cpufreq driver (Lad
        Prabhakar).

   - Update cpuidle core and drivers:

      - Fix three reference count leaks in error code paths in the
        cpuidle core (Qiushi Wu).

      - Convert Qualcomm SPM to a generic cpuidle driver (Stephan
        Gerhold).

      - Fix up the execution order when entering a domain idle state in
        the PSCI driver (Ulf Hansson).

   - Fix a reference counting issue related to clock management and
     clean up two oddities in the PM-runtime framework (Rafael Wysocki,
     Andy Shevchenko).

   - Add ElkhartLake support to the Intel RAPL power capping driver and
     remove an unused local MSR definition from it (Jacob Pan, Sumeet
     Pawnikar).

   - Update devfreq core and drivers:

      - Replace strncpy() with strscpy() in the devfreq core and use
        lockdep asserts instead of manual checks for a locked mutex in
        it (Dmitry Osipenko, Krzysztof Kozlowski).

      - Add a generic imx bus scaling driver and make it register an
        interconnect device (Leonard Crestez, Gustavo A. R. Silva).

      - Make the cpufreq notifier in the tegra30 driver take boosting
        into account and delete an unuseful error message from that
        driver (Dmitry Osipenko, Markus Elfring).

   - Remove unneeded semicolon from the cpupower code (Zou Wei)"

* tag 'pm-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (51 commits)
  cpuidle: Fix three reference count leaks
  PM: runtime: Replace pm_runtime_callbacks_present()
  PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
  PM / devfreq: imx-bus: Fix inconsistent IS_ERR and PTR_ERR
  PM / devfreq: Replace strncpy with strscpy
  PM / devfreq: imx: Register interconnect device
  PM / devfreq: Add generic imx bus scaling driver
  PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()
  PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting
  PM: hibernate: Restrict writes to the resume device
  PM: runtime: clk: Fix clk_pm_runtime_get() error path
  cpuidle: Convert Qualcomm SPM driver to a generic CPUidle driver
  ACPI: EC: PM: s2idle: Extend GPE dispatching debug message
  ACPI: PM: s2idle: Print type of wakeup debug messages
  powercap: RAPL: remove unused local MSR define
  PM: runtime: Make clear what we do when conditions are wrong in rpm_suspend()
  Documentation: admin-guide: pm: Document intel-speed-select
  PM: hibernate: Split off snapshot dev option
  PM: hibernate: Incorporate concurrency handling
  Documentation: ABI: make current_governer_ro as a candidate for removal
  ...
</content>
</entry>
<entry>
<title>fs: convert mpage_readpages to mpage_readahead</title>
<updated>2020-06-02T17:59:07Z</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2020-06-02T04:47:02Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=d4388340ae0bc8397ef5b24342279f7739982918'/>
<id>urn:sha1:d4388340ae0bc8397ef5b24342279f7739982918</id>
<content type='text'>
Implement the new readahead aop and convert all callers (block_dev,
exfat, ext2, fat, gfs2, hpfs, isofs, jfs, nilfs2, ocfs2, omfs, qnx6,
reiserfs &amp; udf).

The callers are all trivial except for GFS2 &amp; OCFS2.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Junxiao Bi &lt;junxiao.bi@oracle.com&gt; # ocfs2
Reviewed-by: Joseph Qi &lt;joseph.qi@linux.alibaba.com&gt; # ocfs2
Reviewed-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: John Hubbard &lt;jhubbard@nvidia.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: William Kucharski &lt;william.kucharski@oracle.com&gt;
Cc: Chao Yu &lt;yuchao0@huawei.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Cc: Eric Biggers &lt;ebiggers@google.com&gt;
Cc: Gao Xiang &lt;gaoxiang25@huawei.com&gt;
Cc: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Cc: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Link: http://lkml.kernel.org/r/20200414150233.24495-17-willy@infradead.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>PM: hibernate: Restrict writes to the resume device</title>
<updated>2020-05-27T15:55:59Z</updated>
<author>
<name>Domenico Andreoli</name>
<email>domenico.andreoli@linux.com</email>
</author>
<published>2020-05-19T18:14:10Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=ad1e4f74c072eaa2c6d77dd710db31aafecd614f'/>
<id>urn:sha1:ad1e4f74c072eaa2c6d77dd710db31aafecd614f</id>
<content type='text'>
Hibernation via snapshot device requires write permission to the swap
block device, the one that more often (but not necessarily) is used to
store the hibernation image.

With this patch, such permissions are granted iff:

 1) snapshot device config option is enabled
 2) swap partition is used as resume device

In other circumstances the swap device is not writable from userspace.

In order to achieve this, every write attempt to a swap device is
checked against the device configured as part of the uswsusp API [0]
using a pointer to the inode struct in memory. If the swap device being
written was not configured for resuming, the write request is denied.

NOTE: this implementation works only for swap block devices, where the
inode configured by swapon (which sets S_SWAPFILE) is the same used
by SNAPSHOT_SET_SWAP_AREA.

In case of swap file, SNAPSHOT_SET_SWAP_AREA indeed receives the inode
of the block device containing the filesystem where the swap file is
located (+ offset in it) which is never passed to swapon and then has
not set S_SWAPFILE.

As result, the swap file itself (as a file) has never an option to be
written from userspace. Instead it remains writable if accessed directly
from the containing block device, which is always writeable from root.

[0] Documentation/power/userland-swsusp.rst

v2:
 - rename is_hibernate_snapshot_dev() to is_hibernate_resume_dev()
 - fix description so to correctly refer to the resume device

Signed-off-by: Domenico Andreoli &lt;domenico.andreoli@linux.com&gt;
Acked-by: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>block: remove the error_sector argument to blkdev_issue_flush</title>
<updated>2020-05-22T14:45:46Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-05-13T12:36:00Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=9398554fb3979852512ff4f1405e759889b45c16'/>
<id>urn:sha1:9398554fb3979852512ff4f1405e759889b45c16</id>
<content type='text'>
The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>block: remove ioctl_by_bdev</title>
<updated>2020-05-21T14:22:20Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-05-19T14:33:21Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=3783daeb1d24696ff00125050353cfce4f5b6239'/>
<id>urn:sha1:3783daeb1d24696ff00125050353cfce4f5b6239</id>
<content type='text'>
No callers left.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>block: add blk_io_schedule() for avoiding task hung in sync dio</title>
<updated>2020-05-13T02:32:42Z</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2020-05-03T01:54:22Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=e6249cdd46e43a7d3bdb8cce5fe24565d6c11e94'/>
<id>urn:sha1:e6249cdd46e43a7d3bdb8cce5fe24565d6c11e94</id>
<content type='text'>
Sync dio could be big, or may take long time in discard or in case of
IO failure.

We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
so apply the same trick for prevent task hung from happening in sync dio.

Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
task hung warning.

Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Cc: Salman Qazi &lt;sqazi@google.com&gt;
Cc: Jesse Barnes &lt;jsbarnes@google.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Bart Van Assche &lt;bvanassche@acm.org&gt;
Cc: Hannes Reinecke &lt;hare@suse.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
</feed>
