<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/block, branch v6.4-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>ublk: fix command op code check</title>
<updated>2023-05-12T15:09:06+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2023-05-05T15:31:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e485bd9e2c419142430ae6fe3e8f64e3059aef50'/>
<id>e485bd9e2c419142430ae6fe3e8f64e3059aef50</id>
<content type='text'>
In case of CONFIG_BLKDEV_UBLK_LEGACY_OPCODES, type of cmd opcode could
be 0 or 'u'; and type can only be 'u' if CONFIG_BLKDEV_UBLK_LEGACY_OPCODES
isn't set.

So fix the wrong check.

Fixes: 2d786e66c966 ("block: ublk: switch to ioctl command encoding")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230505153142.1258336-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In case of CONFIG_BLKDEV_UBLK_LEGACY_OPCODES, type of cmd opcode could
be 0 or 'u'; and type can only be 'u' if CONFIG_BLKDEV_UBLK_LEGACY_OPCODES
isn't set.

So fix the wrong check.

Fixes: 2d786e66c966 ("block: ublk: switch to ioctl command encoding")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230505153142.1258336-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block/rnbd: replace REQ_OP_FLUSH with REQ_OP_WRITE</title>
<updated>2023-05-12T14:56:42+00:00</updated>
<author>
<name>Guoqing Jiang</name>
<email>guoqing.jiang@linux.dev</email>
</author>
<published>2023-05-12T03:46:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5e6e08087a4acb4ee3574cea32dbff0f63c7f608'/>
<id>5e6e08087a4acb4ee3574cea32dbff0f63c7f608</id>
<content type='text'>
Since flush bios are implemented as writes with no data and
the preflush flag per Christoph's comment [1].

And we need to change it in rnbd accordingly. Otherwise, I
got splatting when create fs from rnbd client.

[  464.028545] ------------[ cut here ]------------
[  464.028553] WARNING: CPU: 0 PID: 65 at block/blk-core.c:751 submit_bio_noacct+0x32c/0x5d0
[ ... ]
[  464.028668] CPU: 0 PID: 65 Comm: kworker/0:1H Tainted: G           OE      6.4.0-rc1 #9
[  464.028671] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[  464.028673] Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
[  464.028717] RIP: 0010:submit_bio_noacct+0x32c/0x5d0
[  464.028720] Code: 03 0f 85 51 fe ff ff 48 8b 43 18 8b 88 04 03 00 00 85 c9 0f 85 3f fe ff ff e9 be fd ff ff 0f b6 d0 3c 0d 74 26 83 fa 01 74 21 &lt;0f&gt; 0b b8 0a 00 00 00 e9 56 fd ff ff 4c 89 e7 e8 70 a1 03 00 84 c0
[  464.028722] RSP: 0018:ffffaf3680b57c68 EFLAGS: 00010202
[  464.028724] RAX: 0000000000060802 RBX: ffffa09dcc18bf00 RCX: 0000000000000000
[  464.028726] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffffa09dde081d00
[  464.028727] RBP: ffffaf3680b57c98 R08: ffffa09dde081d00 R09: ffffa09e38327200
[  464.028729] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa09dde081d00
[  464.028730] R13: ffffa09dcb06e1e8 R14: 0000000000000000 R15: 0000000000200000
[  464.028733] FS:  0000000000000000(0000) GS:ffffa09e3bc00000(0000) knlGS:0000000000000000
[  464.028735] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  464.028736] CR2: 000055a4e8206c40 CR3: 0000000119f06000 CR4: 00000000003506f0
[  464.028738] Call Trace:
[  464.028740]  &lt;TASK&gt;
[  464.028746]  submit_bio+0x1b/0x80
[  464.028748]  rnbd_srv_rdma_ev+0x50d/0x10c0 [rnbd_server]
[  464.028754]  ? percpu_ref_get_many.constprop.0+0x55/0x140 [rtrs_server]
[  464.028760]  ? __this_cpu_preempt_check+0x13/0x20
[  464.028769]  process_io_req+0x1dc/0x450 [rtrs_server]
[  464.028775]  rtrs_srv_inv_rkey_done+0x67/0xb0 [rtrs_server]
[  464.028780]  __ib_process_cq+0xbc/0x1f0 [ib_core]
[  464.028793]  ib_cq_poll_work+0x2b/0xa0 [ib_core]
[  464.028804]  process_one_work+0x2a9/0x580

[1]. https://lore.kernel.org/all/ZFHgefWofVt24tRl@infradead.org/

Signed-off-by: Guoqing Jiang &lt;guoqing.jiang@linux.dev&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20230512034631.28686-1-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since flush bios are implemented as writes with no data and
the preflush flag per Christoph's comment [1].

And we need to change it in rnbd accordingly. Otherwise, I
got splatting when create fs from rnbd client.

[  464.028545] ------------[ cut here ]------------
[  464.028553] WARNING: CPU: 0 PID: 65 at block/blk-core.c:751 submit_bio_noacct+0x32c/0x5d0
[ ... ]
[  464.028668] CPU: 0 PID: 65 Comm: kworker/0:1H Tainted: G           OE      6.4.0-rc1 #9
[  464.028671] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[  464.028673] Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
[  464.028717] RIP: 0010:submit_bio_noacct+0x32c/0x5d0
[  464.028720] Code: 03 0f 85 51 fe ff ff 48 8b 43 18 8b 88 04 03 00 00 85 c9 0f 85 3f fe ff ff e9 be fd ff ff 0f b6 d0 3c 0d 74 26 83 fa 01 74 21 &lt;0f&gt; 0b b8 0a 00 00 00 e9 56 fd ff ff 4c 89 e7 e8 70 a1 03 00 84 c0
[  464.028722] RSP: 0018:ffffaf3680b57c68 EFLAGS: 00010202
[  464.028724] RAX: 0000000000060802 RBX: ffffa09dcc18bf00 RCX: 0000000000000000
[  464.028726] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffffa09dde081d00
[  464.028727] RBP: ffffaf3680b57c98 R08: ffffa09dde081d00 R09: ffffa09e38327200
[  464.028729] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa09dde081d00
[  464.028730] R13: ffffa09dcb06e1e8 R14: 0000000000000000 R15: 0000000000200000
[  464.028733] FS:  0000000000000000(0000) GS:ffffa09e3bc00000(0000) knlGS:0000000000000000
[  464.028735] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  464.028736] CR2: 000055a4e8206c40 CR3: 0000000119f06000 CR4: 00000000003506f0
[  464.028738] Call Trace:
[  464.028740]  &lt;TASK&gt;
[  464.028746]  submit_bio+0x1b/0x80
[  464.028748]  rnbd_srv_rdma_ev+0x50d/0x10c0 [rnbd_server]
[  464.028754]  ? percpu_ref_get_many.constprop.0+0x55/0x140 [rtrs_server]
[  464.028760]  ? __this_cpu_preempt_check+0x13/0x20
[  464.028769]  process_io_req+0x1dc/0x450 [rtrs_server]
[  464.028775]  rtrs_srv_inv_rkey_done+0x67/0xb0 [rtrs_server]
[  464.028780]  __ib_process_cq+0xbc/0x1f0 [ib_core]
[  464.028793]  ib_cq_poll_work+0x2b/0xa0 [ib_core]
[  464.028804]  process_one_work+0x2a9/0x580

[1]. https://lore.kernel.org/all/ZFHgefWofVt24tRl@infradead.org/

Signed-off-by: Guoqing Jiang &lt;guoqing.jiang@linux.dev&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20230512034631.28686-1-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nbd: Fix debugfs_create_dir error checking</title>
<updated>2023-05-12T14:56:33+00:00</updated>
<author>
<name>Ivan Orlov</name>
<email>ivan.orlov0322@gmail.com</email>
</author>
<published>2023-05-12T13:05:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4913cfcf014c95f0437db2df1734472fd3e15098'/>
<id>4913cfcf014c95f0437db2df1734472fd3e15098</id>
<content type='text'>
The debugfs_create_dir function returns ERR_PTR in case of error, and the
only correct way to check if an error occurred is 'IS_ERR' inline function.
This patch will replace the null-comparison with IS_ERR.

Signed-off-by: Ivan Orlov &lt;ivan.orlov0322@gmail.com&gt;
Link: https://lore.kernel.org/r/20230512130533.98709-1-ivan.orlov0322@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The debugfs_create_dir function returns ERR_PTR in case of error, and the
only correct way to check if an error occurred is 'IS_ERR' inline function.
This patch will replace the null-comparison with IS_ERR.

Signed-off-by: Ivan Orlov &lt;ivan.orlov0322@gmail.com&gt;
Link: https://lore.kernel.org/r/20230512130533.98709-1-ivan.orlov0322@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-6.4/io_uring-2023-05-07' of git://git.kernel.dk/linux</title>
<updated>2023-05-07T17:00:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-05-07T17:00:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=03e5cb7b50feb687508946a702febaba24c77f0b'/>
<id>03e5cb7b50feb687508946a702febaba24c77f0b</id>
<content type='text'>
Pull more io_uring updates from Jens Axboe:
 "Nothing major in here, just two different parts:

   - A small series from Breno that enables passing the full SQE down
     for -&gt;uring_cmd().

     This is a prerequisite for enabling full network socket operations.
     Queued up a bit late because of some stylistic concerns that got
     resolved, would be nice to have this in 6.4-rc1 so the dependent
     work will be easier to handle for 6.5.

   - Fix for the huge page coalescing, which was a regression introduced
     in the 6.3 kernel release (Tobias)"

* tag 'for-6.4/io_uring-2023-05-07' of git://git.kernel.dk/linux:
  io_uring: Remove unnecessary BUILD_BUG_ON
  io_uring: Pass whole sqe to commands
  io_uring: Create a helper to return the SQE size
  io_uring/rsrc: check for nonconsecutive pages
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more io_uring updates from Jens Axboe:
 "Nothing major in here, just two different parts:

   - A small series from Breno that enables passing the full SQE down
     for -&gt;uring_cmd().

     This is a prerequisite for enabling full network socket operations.
     Queued up a bit late because of some stylistic concerns that got
     resolved, would be nice to have this in 6.4-rc1 so the dependent
     work will be easier to handle for 6.5.

   - Fix for the huge page coalescing, which was a regression introduced
     in the 6.3 kernel release (Tobias)"

* tag 'for-6.4/io_uring-2023-05-07' of git://git.kernel.dk/linux:
  io_uring: Remove unnecessary BUILD_BUG_ON
  io_uring: Pass whole sqe to commands
  io_uring: Create a helper to return the SQE size
  io_uring/rsrc: check for nonconsecutive pages
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux</title>
<updated>2023-05-06T15:28:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-05-06T15:28:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a3b111b046f6ce5dff168af203daf2f46f3afb29'/>
<id>a3b111b046f6ce5dff168af203daf2f46f3afb29</id>
<content type='text'>
Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Improve raid5 sequential IO performance on spinning disks, which
        fixes a regression since v6.0 (Jan Kara)
      - Fix bitmap offset types, which fixes an issue introduced in this
        merge window (Jonathan Derrick)

 - Cleanup of hweight type used for cgroup writeback (Maxim)

 - Fix a regression with the "has_submit_bio" changes across partitions
   (Ming)

 - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.

   We used to set this flag on queues non blk-mq queues, and hence some
   drivers clear it unconditionally. Since all of these have since been
   converted to true blk-mq drivers, drop the useless clear as the bit
   is not set (Chaitanya)

 - Fix the flags being set in a bio for a flush for drbd (Christoph)

 - Cleanup and deduplication of the code handling setting block device
   capacity (Damien)

 - Fix for ublk handling IO timeouts (Ming)

 - Fix for a regression in blk-cgroup teardown (Tao)

 - NBD documentation and code fixes (Eric)

 - Convert blk-integrity to using device_attributes rather than a second
   kobject to manage lifetimes (Thomas)

* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
  ublk: add timeout handler
  drbd: correctly submit flush bio on barrier
  mailmap: add mailmap entries for Jens Axboe
  block: Skip destroyed blkg when restart in blkg_destroy_all()
  writeback: fix call of incorrect macro
  md: Fix bitmap offset type in sb writer
  md/raid5: Improve performance for sequential IO
  docs nbd: userspace NBD now favors github over sourceforge
  block nbd: use req.cookie instead of req.handle
  uapi nbd: add cookie alias to handle
  uapi nbd: improve doc links to userspace spec
  blk-integrity: register sysfs attributes on struct device
  blk-integrity: convert to struct device_attribute
  blk-integrity: use sysfs_emit
  block/drivers: remove dead clear of random flag
  block: sync part's -&gt;bd_has_submit_bio with disk's
  block: Cleanup set_capacity()/bdev_set_nr_sectors()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Improve raid5 sequential IO performance on spinning disks, which
        fixes a regression since v6.0 (Jan Kara)
      - Fix bitmap offset types, which fixes an issue introduced in this
        merge window (Jonathan Derrick)

 - Cleanup of hweight type used for cgroup writeback (Maxim)

 - Fix a regression with the "has_submit_bio" changes across partitions
   (Ming)

 - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.

   We used to set this flag on queues non blk-mq queues, and hence some
   drivers clear it unconditionally. Since all of these have since been
   converted to true blk-mq drivers, drop the useless clear as the bit
   is not set (Chaitanya)

 - Fix the flags being set in a bio for a flush for drbd (Christoph)

 - Cleanup and deduplication of the code handling setting block device
   capacity (Damien)

 - Fix for ublk handling IO timeouts (Ming)

 - Fix for a regression in blk-cgroup teardown (Tao)

 - NBD documentation and code fixes (Eric)

 - Convert blk-integrity to using device_attributes rather than a second
   kobject to manage lifetimes (Thomas)

* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
  ublk: add timeout handler
  drbd: correctly submit flush bio on barrier
  mailmap: add mailmap entries for Jens Axboe
  block: Skip destroyed blkg when restart in blkg_destroy_all()
  writeback: fix call of incorrect macro
  md: Fix bitmap offset type in sb writer
  md/raid5: Improve performance for sequential IO
  docs nbd: userspace NBD now favors github over sourceforge
  block nbd: use req.cookie instead of req.handle
  uapi nbd: add cookie alias to handle
  uapi nbd: improve doc links to userspace spec
  blk-integrity: register sysfs attributes on struct device
  blk-integrity: convert to struct device_attribute
  blk-integrity: use sysfs_emit
  block/drivers: remove dead clear of random flag
  block: sync part's -&gt;bd_has_submit_bio with disk's
  block: Cleanup set_capacity()/bdev_set_nr_sectors()
</pre>
</div>
</content>
</entry>
<entry>
<title>io_uring: Pass whole sqe to commands</title>
<updated>2023-05-04T14:19:05+00:00</updated>
<author>
<name>Breno Leitao</name>
<email>leitao@debian.org</email>
</author>
<published>2023-05-04T12:18:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fd9b8547bc5c34186dc42ea05fb4380d21695374'/>
<id>fd9b8547bc5c34186dc42ea05fb4380d21695374</id>
<content type='text'>
Currently uring CMD operation relies on having large SQEs, but future
operations might want to use normal SQE.

The io_uring_cmd currently only saves the payload (cmd) part of the SQE,
but, for commands that use normal SQE size, it might be necessary to
access the initial SQE fields outside of the payload/cmd block.  So,
saves the whole SQE other than just the pdu.

This changes slightly how the io_uring_cmd works, since the cmd
structures and callbacks are not opaque to io_uring anymore. I.e, the
callbacks can look at the SQE entries, not only, in the cmd structure.

The main advantage is that we don't need to create custom structures for
simple commands.

Creates io_uring_sqe_cmd() that returns the cmd private data as a null
pointer and avoids casting in the callee side.
Also, make most of ublk_drv's sqe-&gt;cmd priv structure into const, and use
io_uring_sqe_cmd() to get the private structure, removing the unwanted
cast. (There is one case where the cast is still needed since the
header-&gt;{len,addr} is updated in the private structure)

Suggested-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/20230504121856.904491-3-leitao@debian.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently uring CMD operation relies on having large SQEs, but future
operations might want to use normal SQE.

The io_uring_cmd currently only saves the payload (cmd) part of the SQE,
but, for commands that use normal SQE size, it might be necessary to
access the initial SQE fields outside of the payload/cmd block.  So,
saves the whole SQE other than just the pdu.

This changes slightly how the io_uring_cmd works, since the cmd
structures and callbacks are not opaque to io_uring anymore. I.e, the
callbacks can look at the SQE entries, not only, in the cmd structure.

The main advantage is that we don't need to create custom structures for
simple commands.

Creates io_uring_sqe_cmd() that returns the cmd private data as a null
pointer and avoids casting in the callee side.
Also, make most of ublk_drv's sqe-&gt;cmd priv structure into const, and use
io_uring_sqe_cmd() to get the private structure, removing the unwanted
cast. (There is one case where the cast is still needed since the
header-&gt;{len,addr} is updated in the private structure)

Suggested-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Link: https://lore.kernel.org/r/20230504121856.904491-3-leitao@debian.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ublk: add timeout handler</title>
<updated>2023-05-03T15:39:18+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2023-05-02T02:42:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c0b79b0ff53be5b05be98e3caaa6a39de1fe9520'/>
<id>c0b79b0ff53be5b05be98e3caaa6a39de1fe9520</id>
<content type='text'>
Add timeout handler, so that we can provide forward progress guarantee for
unprivileged ublk, which can't be trusted.

One thing is that sync() calls sync_bdevs(wait) for all block devices after
running sync_bdevs(no_wait), and if one device can't move on, the sync() won't
return any more.

Add timeout for unprivileged ublk to avoid such affect for other users which call
sync() syscall.

Meantime clear UBLK_F_USER_RECOVERY_REISSUE for unprivileged ublk since
that feature may cause IO hang too.

Fixes: 4093cb5a0634 ("ublk_drv: add mechanism for supporting unprivileged ublk device")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230502024231.888498-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add timeout handler, so that we can provide forward progress guarantee for
unprivileged ublk, which can't be trusted.

One thing is that sync() calls sync_bdevs(wait) for all block devices after
running sync_bdevs(no_wait), and if one device can't move on, the sync() won't
return any more.

Add timeout for unprivileged ublk to avoid such affect for other users which call
sync() syscall.

Meantime clear UBLK_F_USER_RECOVERY_REISSUE for unprivileged ublk since
that feature may cause IO hang too.

Fixes: 4093cb5a0634 ("ublk_drv: add mechanism for supporting unprivileged ublk device")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230502024231.888498-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drbd: correctly submit flush bio on barrier</title>
<updated>2023-05-03T15:36:56+00:00</updated>
<author>
<name>Christoph Böhmwalder</name>
<email>christoph.boehmwalder@linbit.com</email>
</author>
<published>2023-05-03T12:19:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3899d94e3831ee07ea6821c032dc297aec80586a'/>
<id>3899d94e3831ee07ea6821c032dc297aec80586a</id>
<content type='text'>
When we receive a flush command (or "barrier" in DRBD), we currently use
a REQ_OP_FLUSH with the REQ_PREFLUSH flag set.

The correct way to submit a flush bio is by using a REQ_OP_WRITE without
any data, and set the REQ_PREFLUSH flag.

Since commit b4a6bb3a67aa ("block: add a sanity check for non-write
flush/fua bios"), this triggers a warning in the block layer, but this
has been broken for quite some time before that.

So use the correct set of flags to actually make the flush happen.

Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: stable@vger.kernel.org
Fixes: f9ff0da56437 ("drbd: allow parallel flushes for multi-volume resources")
Reported-by: Thomas Voegtle &lt;tv@lio96.de&gt;
Signed-off-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230503121937.17232-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When we receive a flush command (or "barrier" in DRBD), we currently use
a REQ_OP_FLUSH with the REQ_PREFLUSH flag set.

The correct way to submit a flush bio is by using a REQ_OP_WRITE without
any data, and set the REQ_PREFLUSH flag.

Since commit b4a6bb3a67aa ("block: add a sanity check for non-write
flush/fua bios"), this triggers a warning in the block layer, but this
has been broken for quite some time before that.

So use the correct set of flags to actually make the flush happen.

Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: stable@vger.kernel.org
Fixes: f9ff0da56437 ("drbd: allow parallel flushes for multi-volume resources")
Reported-by: Thomas Voegtle &lt;tv@lio96.de&gt;
Signed-off-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230503121937.17232-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2023-04-28T02:42:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-28T02:42:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7fa8a8ee9400fe8ec188426e40e481717bc5e924'/>
<id>7fa8a8ee9400fe8ec188426e40e481717bc5e924</id>
<content type='text'>
Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in -&gt;map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in -&gt;map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>block nbd: use req.cookie instead of req.handle</title>
<updated>2023-04-28T01:15:11+00:00</updated>
<author>
<name>Eric Blake</name>
<email>eblake@redhat.com</email>
</author>
<published>2023-04-10T18:06:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd9e9916c32fd4b4fb4e879e05bd1568ee02ec93'/>
<id>bd9e9916c32fd4b4fb4e879e05bd1568ee02ec93</id>
<content type='text'>
The NBD spec was recently changed [1] to refer to the opaque client
identifier as a 'cookie' rather than a 'handle', but has for a much
longer time listed it as a 64-bit value, and declares that all values
in the NBD protocol are sent in network byte order (big-endian).

Because the value is opaque to the server, it doesn't usually matter
what endianness we send as the client - as long as we are consistent
that either we byte-swap on both write and read, or on neither, then
we can match server replies back to our requests.  That said, our
internal use of the cookie is as a 64-bit number (well, as two 32-bit
numbers concatenated together), rather than as 8 individual bytes; so
prior to this commit, we ARE leaking the native endianness of our
internals as a client out to the server.  We don't know of any server
that will actually inspect the opaque value and behave differently
depending on whether a little-endian or big-endian client is sending
requests, but since we DO log the cookie value, a wireshark capture of
the network traffic is easier to correlate back to the kernel traffic
of a big-endian host (where the u64 and char[8] representations are
the same) than of a little-endian host (where if wireshark honors the
NBD spec and displays a u64 in network byte order, it is byte-swapped
from what the kernel logged).

The fix in this patch is thus two-part: it now consistently uses
network byte order for the opaque value (no difference to a big-endian
machine, but an extra byteswap on a little-endian machine; probably in
the noise compared to the overhead of network traffic in general), and
now uses a 64-bit integer instead of char[8] as its preferred access
to the opaque value (direct assignment instead of memcpy()).

Signed-off-by: Eric Blake &lt;eblake@redhat.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Link: https://lore.kernel.org/r/20230410180611.1051618-4-eblake@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The NBD spec was recently changed [1] to refer to the opaque client
identifier as a 'cookie' rather than a 'handle', but has for a much
longer time listed it as a 64-bit value, and declares that all values
in the NBD protocol are sent in network byte order (big-endian).

Because the value is opaque to the server, it doesn't usually matter
what endianness we send as the client - as long as we are consistent
that either we byte-swap on both write and read, or on neither, then
we can match server replies back to our requests.  That said, our
internal use of the cookie is as a 64-bit number (well, as two 32-bit
numbers concatenated together), rather than as 8 individual bytes; so
prior to this commit, we ARE leaking the native endianness of our
internals as a client out to the server.  We don't know of any server
that will actually inspect the opaque value and behave differently
depending on whether a little-endian or big-endian client is sending
requests, but since we DO log the cookie value, a wireshark capture of
the network traffic is easier to correlate back to the kernel traffic
of a big-endian host (where the u64 and char[8] representations are
the same) than of a little-endian host (where if wireshark honors the
NBD spec and displays a u64 in network byte order, it is byte-swapped
from what the kernel logged).

The fix in this patch is thus two-part: it now consistently uses
network byte order for the opaque value (no difference to a big-endian
machine, but an extra byteswap on a little-endian machine; probably in
the noise compared to the overhead of network traffic in general), and
now uses a 64-bit integer instead of char[8] as its preferred access
to the opaque value (direct assignment instead of memcpy()).

Signed-off-by: Eric Blake &lt;eblake@redhat.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Link: https://lore.kernel.org/r/20230410180611.1051618-4-eblake@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
</feed>
