<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/md, branch v2.6.32.51</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>md/raid5: abort any pending parity operations when array fails.</title>
<updated>2011-11-26T17:10:34+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2011-11-08T05:22:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=61d433c479a6ccfed6a7e73e6111ca8fa0348c63'/>
<id>61d433c479a6ccfed6a7e73e6111ca8fa0348c63</id>
<content type='text'>
commit 9a3f530f39f4490eaa18b02719fb74ce5f4d2d86 upstream.

When the number of failed devices exceeds the allowed number
we must abort any active parity operations (checks or updates) as they
are no longer meaningful, and can lead to a BUG_ON in
handle_parity_checks6.

This bug was introduce by commit 6c0069c0ae9659e3a91b68eaed06a5c6c37f45c8
in 2.6.29.

Reported-by: Manish Katiyar &lt;mkatiyar@gmail.com&gt;
Tested-by: Manish Katiyar &lt;mkatiyar@gmail.com&gt;
Acked-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9a3f530f39f4490eaa18b02719fb74ce5f4d2d86 upstream.

When the number of failed devices exceeds the allowed number
we must abort any active parity operations (checks or updates) as they
are no longer meaningful, and can lead to a BUG_ON in
handle_parity_checks6.

This bug was introduce by commit 6c0069c0ae9659e3a91b68eaed06a5c6c37f45c8
in 2.6.29.

Reported-by: Manish Katiyar &lt;mkatiyar@gmail.com&gt;
Tested-by: Manish Katiyar &lt;mkatiyar@gmail.com&gt;
Acked-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.</title>
<updated>2011-11-07T20:31:58+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2011-09-10T07:21:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c28f366a6ef9b6e14e069e7d750c32d73544444e'/>
<id>c28f366a6ef9b6e14e069e7d750c32d73544444e</id>
<content type='text'>
commit 27a7b260f71439c40546b43588448faac01adb93 upstream.

0.90 metadata uses an unsigned 32bit number to count the number of
kilobytes used from each device.
This should allow up to 4TB per device.
However we multiply this by 2 (to get sectors) before casting to a
larger type, so sizes above 2TB get truncated.

Also we allow rdev-&gt;sectors to be larger than 4TB, so it is possible
for the array to be resized larger than the metadata can handle.
So make sure rdev-&gt;sectors never exceeds 4TB when 0.90 metadata is in
used.

Also the sanity check at the end of super_90_load should include level
1 as it used -&gt;size too. (RAID0 and Linear don't use -&gt;size at all).

Reported-by: Pim Zandbergen &lt;P.Zandbergen@macroscoop.nl&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 27a7b260f71439c40546b43588448faac01adb93 upstream.

0.90 metadata uses an unsigned 32bit number to count the number of
kilobytes used from each device.
This should allow up to 4TB per device.
However we multiply this by 2 (to get sectors) before casting to a
larger type, so sizes above 2TB get truncated.

Also we allow rdev-&gt;sectors to be larger than 4TB, so it is possible
for the array to be resized larger than the metadata can handle.
So make sure rdev-&gt;sectors never exceeds 4TB when 0.90 metadata is in
used.

Also the sanity check at the end of super_90_load should include level
1 as it used -&gt;size too. (RAID0 and Linear don't use -&gt;size at all).

Reported-by: Pim Zandbergen &lt;P.Zandbergen@macroscoop.nl&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md/linear: avoid corrupting structure while waiting for rcu_free to complete.</title>
<updated>2011-11-07T20:31:52+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2011-08-25T04:43:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=372994e9fd5cadbacdfcc8724b590193d136c947'/>
<id>372994e9fd5cadbacdfcc8724b590193d136c947</id>
<content type='text'>
commit 1b6afa17581027218088a18a9ceda600e0ddba7a upstream.

I don't know what I was thinking putting 'rcu' after a dynamically
sized array!  The array could still be in use when we call rcu_free()
(That is the point) so we mustn't corrupt it.

Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1b6afa17581027218088a18a9ceda600e0ddba7a upstream.

I don't know what I was thinking putting 'rcu' after a dynamically
sized array!  The array could still be in use when we call rcu_free()
(That is the point) so we mustn't corrupt it.

Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>dm: fix idr leak on module removal</title>
<updated>2011-08-08T17:23:21+00:00</updated>
<author>
<name>Alasdair G Kergon</name>
<email>agk@redhat.com</email>
</author>
<published>2011-08-02T11:32:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3d247615d6b54f39e32b9b27a148e4a88dd3b9ca'/>
<id>3d247615d6b54f39e32b9b27a148e4a88dd3b9ca</id>
<content type='text'>
commit d15b774c2920d55e3d58275c97fbe3adc3afde38 upstream.

Destroy _minor_idr when unloading the core dm module.  (Found by kmemleak.)

Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d15b774c2920d55e3d58275c97fbe3adc3afde38 upstream.

Destroy _minor_idr when unloading the core dm module.  (Found by kmemleak.)

Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>dm mpath: fix potential NULL pointer in feature arg processing</title>
<updated>2011-08-08T17:23:21+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2011-08-02T11:32:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c72ff34c937a4572946fdcd79ecbff2fe81f7654'/>
<id>c72ff34c937a4572946fdcd79ecbff2fe81f7654</id>
<content type='text'>
commit 286f367dad40beb3234a18c17391d03ba939a7f3 upstream.

Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 286f367dad40beb3234a18c17391d03ba939a7f3 upstream.

Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md: avoid endless recovery loop when waiting for fail device to complete.</title>
<updated>2011-07-13T03:29:25+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2011-06-28T06:59:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1ca39696ba621b0737c78af2c104939c60b29ce4'/>
<id>1ca39696ba621b0737c78af2c104939c60b29ce4</id>
<content type='text'>
commit 4274215d24633df7302069e51426659d4759c5ed upstream.

If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Reported-by: Jim Paradis &lt;james.paradis@stratus.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4274215d24633df7302069e51426659d4759c5ed upstream.

If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Reported-by: Jim Paradis &lt;james.paradis@stratus.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: fix FUA request handling in ops_run_io()</title>
<updated>2011-06-23T22:24:08+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@gmail.com</email>
</author>
<published>2011-06-14T04:20:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c0877c4bc4ac2d8a510e3b1a45a4f1eb18cf2a5e'/>
<id>c0877c4bc4ac2d8a510e3b1a45a4f1eb18cf2a5e</id>
<content type='text'>
commit b062962edb086011e94ec4d9eb3f6a6d814f2a8f upstream.

Commit e9c7469bb4f5 ("md: implment REQ_FLUSH/FUA support")
introduced R5_WantFUA flag and set rw to WRITE_FUA in that case.
However remaining code still checks whether rw is exactly same
as WRITE or not, so FUAed-write ends up with being treated as
READ. Fix it.

This bug has been present since 2.6.37 and the fix is suitable for any
-stable kernel since then.  It is not clear why this has not caused
more problems.

Cc: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b062962edb086011e94ec4d9eb3f6a6d814f2a8f upstream.

Commit e9c7469bb4f5 ("md: implment REQ_FLUSH/FUA support")
introduced R5_WantFUA flag and set rw to WRITE_FUA in that case.
However remaining code still checks whether rw is exactly same
as WRITE or not, so FUAed-write ends up with being treated as
READ. Fix it.

This bug has been present since 2.6.37 and the fix is suitable for any
-stable kernel since then.  It is not clear why this has not caused
more problems.

Cc: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: fix raid5_set_bi_hw_segments</title>
<updated>2011-06-23T22:24:08+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@gmail.com</email>
</author>
<published>2011-06-13T05:48:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6f4976aa404e521e7d57f1b703856210a3669683'/>
<id>6f4976aa404e521e7d57f1b703856210a3669683</id>
<content type='text'>
commit 9b2dc8b665932a8e681a7ab3237f60475e75e161 upstream.

The @bio-&gt;bi_phys_segments consists of active stripes count in the
lower 16 bits and processed stripes count in the upper 16 bits. So
logical-OR operator should be bitwise one.

This bug has been present since 2.6.27 and the fix is suitable for any
-stable kernel since then.  Fortunately the bad code is only used on
error paths and is relatively unlikely to be hit.

Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9b2dc8b665932a8e681a7ab3237f60475e75e161 upstream.

The @bio-&gt;bi_phys_segments consists of active stripes count in the
lower 16 bits and processed stripes count in the upper 16 bits. So
logical-OR operator should be bitwise one.

This bug has been present since 2.6.27 and the fix is suitable for any
-stable kernel since then.  Fortunately the bad code is only used on
error paths and is relatively unlikely to be hit.

Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>md: check -&gt;hot_remove_disk when removing disk</title>
<updated>2011-06-23T22:24:08+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@gmail.com</email>
</author>
<published>2011-06-09T01:42:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=58d16045d9b84605251ca2a1faabaa665a1bc159'/>
<id>58d16045d9b84605251ca2a1faabaa665a1bc159</id>
<content type='text'>
commit 01393f3d5836b7d62e925e6f4658a7eb22b83a11 upstream.

Check pers-&gt;hot_remove_disk instead of pers-&gt;hot_add_disk in slot_store()
during disk removal. The linear personality only has -&gt;hot_add_disk and
no -&gt;hot_remove_disk, so that removing disk in the array resulted to
following kernel bug:

$ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3]
$ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [&lt;          (null)&gt;]           (null)
 PGD c9f5d067 PUD 8575a067 PMD 0
 Oops: 0010 [#1] SMP
 CPU 2
 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg

 Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[&lt;0000000000000000&gt;]  [&lt;          (null)&gt;]           (null)
 RSP: 0018:ffff880085757df0  EFLAGS: 00010282
 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e
 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000
 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a
 R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff
 R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000
 FS:  00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000)
 Stack:
  ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000
  ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90
  ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98
 Call Trace:
  [&lt;ffffffff8138496a&gt;] ? slot_store+0xaa/0x265
  [&lt;ffffffff81384bae&gt;] rdev_attr_store+0x89/0xa8
  [&lt;ffffffff8115a96a&gt;] sysfs_write_file+0x108/0x144
  [&lt;ffffffff81106b87&gt;] vfs_write+0xb1/0x10d
  [&lt;ffffffff8106e6c0&gt;] ? trace_hardirqs_on_caller+0x111/0x135
  [&lt;ffffffff81106cac&gt;] sys_write+0x4d/0x77
  [&lt;ffffffff814fe702&gt;] system_call_fastpath+0x16/0x1b
 Code:  Bad RIP value.
 RIP  [&lt;          (null)&gt;]           (null)
  RSP &lt;ffff880085757df0&gt;
 CR2: 0000000000000000
 ---[ end trace ba5fc64319a826fb ]---

Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 01393f3d5836b7d62e925e6f4658a7eb22b83a11 upstream.

Check pers-&gt;hot_remove_disk instead of pers-&gt;hot_add_disk in slot_store()
during disk removal. The linear personality only has -&gt;hot_add_disk and
no -&gt;hot_remove_disk, so that removing disk in the array resulted to
following kernel bug:

$ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3]
$ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [&lt;          (null)&gt;]           (null)
 PGD c9f5d067 PUD 8575a067 PMD 0
 Oops: 0010 [#1] SMP
 CPU 2
 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg

 Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[&lt;0000000000000000&gt;]  [&lt;          (null)&gt;]           (null)
 RSP: 0018:ffff880085757df0  EFLAGS: 00010282
 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e
 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000
 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a
 R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff
 R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000
 FS:  00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000)
 Stack:
  ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000
  ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90
  ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98
 Call Trace:
  [&lt;ffffffff8138496a&gt;] ? slot_store+0xaa/0x265
  [&lt;ffffffff81384bae&gt;] rdev_attr_store+0x89/0xa8
  [&lt;ffffffff8115a96a&gt;] sysfs_write_file+0x108/0x144
  [&lt;ffffffff81106b87&gt;] vfs_write+0xb1/0x10d
  [&lt;ffffffff8106e6c0&gt;] ? trace_hardirqs_on_caller+0x111/0x135
  [&lt;ffffffff81106cac&gt;] sys_write+0x4d/0x77
  [&lt;ffffffff814fe702&gt;] system_call_fastpath+0x16/0x1b
 Code:  Bad RIP value.
 RIP  [&lt;          (null)&gt;]           (null)
  RSP &lt;ffff880085757df0&gt;
 CR2: 0000000000000000
 ---[ end trace ba5fc64319a826fb ]---

Signed-off-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>dm table: reject devices without request fns</title>
<updated>2011-06-23T22:24:04+00:00</updated>
<author>
<name>Milan Broz</name>
<email>mbroz@redhat.com</email>
</author>
<published>2011-05-29T12:02:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a4401a63a8d0594dfbc4d2e7bd2c9779f6b85a45'/>
<id>a4401a63a8d0594dfbc4d2e7bd2c9779f6b85a45</id>
<content type='text'>
commit f4808ca99a203f20b4475601748e44b25a65bdec upstream.

This patch adds a check that a block device has a request function
defined before it is used.  Otherwise, misconfiguration can cause an oops.

Because we are allowing devices with zero size e.g. an offline multipath
device as in commit 2cd54d9bedb79a97f014e86c0da393416b264eb3
("dm: allow offline devices") there needs to be an additional check
to ensure devices are initialised.  Some block devices, like a loop
device without a backing file, exist but have no request function.

Reproducer is trivial: dm-mirror on unbound loop device
(no backing file on loop devices)

dmsetup create x --table "0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0"

and mirror resync will immediatelly cause OOps.

BUG: unable to handle kernel NULL pointer dereference at   (null)
 ? generic_make_request+0x2bd/0x590
 ? kmem_cache_alloc+0xad/0x190
 submit_bio+0x53/0xe0
 ? bio_add_page+0x3b/0x50
 dispatch_io+0x1ca/0x210 [dm_mod]
 ? read_callback+0x0/0xd0 [dm_mirror]
 dm_io+0xbb/0x290 [dm_mod]
 do_mirror+0x1e0/0x748 [dm_mirror]

Signed-off-by: Milan Broz &lt;mbroz@redhat.com&gt;
Reported-by: Zdenek Kabelac &lt;zkabelac@redhat.com&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f4808ca99a203f20b4475601748e44b25a65bdec upstream.

This patch adds a check that a block device has a request function
defined before it is used.  Otherwise, misconfiguration can cause an oops.

Because we are allowing devices with zero size e.g. an offline multipath
device as in commit 2cd54d9bedb79a97f014e86c0da393416b264eb3
("dm: allow offline devices") there needs to be an additional check
to ensure devices are initialised.  Some block devices, like a loop
device without a backing file, exist but have no request function.

Reproducer is trivial: dm-mirror on unbound loop device
(no backing file on loop devices)

dmsetup create x --table "0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0"

and mirror resync will immediatelly cause OOps.

BUG: unable to handle kernel NULL pointer dereference at   (null)
 ? generic_make_request+0x2bd/0x590
 ? kmem_cache_alloc+0xad/0x190
 submit_bio+0x53/0xe0
 ? bio_add_page+0x3b/0x50
 dispatch_io+0x1ca/0x210 [dm_mod]
 ? read_callback+0x0/0xd0 [dm_mirror]
 dm_io+0xbb/0x290 [dm_mod]
 do_mirror+0x1e0/0x748 [dm_mirror]

Signed-off-by: Milan Broz &lt;mbroz@redhat.com&gt;
Reported-by: Zdenek Kabelac &lt;zkabelac@redhat.com&gt;
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Alasdair G Kergon &lt;agk@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
</feed>
