<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/scsi, branch v4.2-rc7</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi</title>
<updated>2015-08-15T20:54:53+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-08-15T20:54:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1efdb5f0a9243ca8f3460a5ce1b407b06a021f02'/>
<id>1efdb5f0a9243ca8f3460a5ce1b407b06a021f02</id>
<content type='text'>
Pull SCSI fixes from James Bottomley:
 "This has two libfc fixes for bugs causing rare crashes, one iscsi fix
  for a potential hang on shutdown, and a fix for an I/O blocksize issue
  which caused a regression"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix maximum I/O size for BLOCK_PC requests
  libfc: Fix fc_fcp_cleanup_each_cmd()
  libfc: Fix fc_exch_recv_req() error path
  libiscsi: Fix host busy blocking during connection teardown
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull SCSI fixes from James Bottomley:
 "This has two libfc fixes for bugs causing rare crashes, one iscsi fix
  for a potential hang on shutdown, and a fix for an I/O blocksize issue
  which caused a regression"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix maximum I/O size for BLOCK_PC requests
  libfc: Fix fc_fcp_cleanup_each_cmd()
  libfc: Fix fc_exch_recv_req() error path
  libiscsi: Fix host busy blocking during connection teardown
</pre>
</div>
</content>
</entry>
<entry>
<title>sd: Fix maximum I/O size for BLOCK_PC requests</title>
<updated>2015-08-12T18:54:37+00:00</updated>
<author>
<name>Martin K. Petersen</name>
<email>martin.petersen@oracle.com</email>
</author>
<published>2015-06-23T16:13:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4f258a46346c03fa0bbb6199ffaf4e1f9f599660'/>
<id>4f258a46346c03fa0bbb6199ffaf4e1f9f599660</id>
<content type='text'>
Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum
size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK
LIMITS VPD. This had the unfortunate effect of also limiting the maximum
size of non-filesystem requests sent to the device through sg/bsg.

Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue
limit directly.

Also update the comment in blk_limits_max_hw_sectors() to clarify that
max_hw_sectors defines the limit for the I/O controller only.

Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Reported-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Tested-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum
size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK
LIMITS VPD. This had the unfortunate effect of also limiting the maximum
size of non-filesystem requests sent to the device through sg/bsg.

Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue
limit directly.

Also update the comment in blk_limits_max_hw_sectors() to clarify that
max_hw_sectors defines the limit for the I/O controller only.

Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Reported-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Tested-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libfc: Fix fc_fcp_cleanup_each_cmd()</title>
<updated>2015-08-12T18:24:21+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@sandisk.com</email>
</author>
<published>2015-06-05T21:20:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8f2777f53e3d5ad8ef2a176a4463a5c8e1a16431'/>
<id>8f2777f53e3d5ad8ef2a176a4463a5c8e1a16431</id>
<content type='text'>
Since fc_fcp_cleanup_cmd() can sleep this function must not
be called while holding a spinlock. This patch avoids that
fc_fcp_cleanup_each_cmd() triggers the following bug:

BUG: scheduling while atomic: sg_reset/1512/0x00000202
1 lock held by sg_reset/1512:
 #0:  (&amp;(&amp;fsp-&gt;scsi_pkt_lock)-&gt;rlock){+.-...}, at: [&lt;ffffffffc0225cd5&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Preemption disabled at:[&lt;ffffffffc0225cd5&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Call Trace:
 [&lt;ffffffff816c612c&gt;] dump_stack+0x4f/0x7b
 [&lt;ffffffff810828bc&gt;] __schedule_bug+0x6c/0xd0
 [&lt;ffffffff816c87aa&gt;] __schedule+0x71a/0xa10
 [&lt;ffffffff816c8ad2&gt;] schedule+0x32/0x80
 [&lt;ffffffffc0217eac&gt;] fc_seq_set_resp+0xac/0x100 [libfc]
 [&lt;ffffffffc0218b11&gt;] fc_exch_done+0x41/0x60 [libfc]
 [&lt;ffffffffc0225cff&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xcf/0x150 [libfc]
 [&lt;ffffffffc0225f43&gt;] fc_eh_device_reset+0x1c3/0x270 [libfc]
 [&lt;ffffffff814a2cc9&gt;] scsi_try_bus_device_reset+0x29/0x60
 [&lt;ffffffff814a3908&gt;] scsi_ioctl_reset+0x258/0x2d0
 [&lt;ffffffff814a2650&gt;] scsi_ioctl+0x150/0x440
 [&lt;ffffffff814b3a9d&gt;] sd_ioctl+0xad/0x120
 [&lt;ffffffff8132f266&gt;] blkdev_ioctl+0x1b6/0x810
 [&lt;ffffffff811da608&gt;] block_ioctl+0x38/0x40
 [&lt;ffffffff811b4e08&gt;] do_vfs_ioctl+0x2f8/0x530
 [&lt;ffffffff811b50c1&gt;] SyS_ioctl+0x81/0xa0
 [&lt;ffffffff816cf8b2&gt;] system_call_fastpath+0x16/0x7a

Signed-off-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Vasu Dev &lt;vasu.dev@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since fc_fcp_cleanup_cmd() can sleep this function must not
be called while holding a spinlock. This patch avoids that
fc_fcp_cleanup_each_cmd() triggers the following bug:

BUG: scheduling while atomic: sg_reset/1512/0x00000202
1 lock held by sg_reset/1512:
 #0:  (&amp;(&amp;fsp-&gt;scsi_pkt_lock)-&gt;rlock){+.-...}, at: [&lt;ffffffffc0225cd5&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Preemption disabled at:[&lt;ffffffffc0225cd5&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Call Trace:
 [&lt;ffffffff816c612c&gt;] dump_stack+0x4f/0x7b
 [&lt;ffffffff810828bc&gt;] __schedule_bug+0x6c/0xd0
 [&lt;ffffffff816c87aa&gt;] __schedule+0x71a/0xa10
 [&lt;ffffffff816c8ad2&gt;] schedule+0x32/0x80
 [&lt;ffffffffc0217eac&gt;] fc_seq_set_resp+0xac/0x100 [libfc]
 [&lt;ffffffffc0218b11&gt;] fc_exch_done+0x41/0x60 [libfc]
 [&lt;ffffffffc0225cff&gt;] fc_fcp_cleanup_each_cmd.isra.21+0xcf/0x150 [libfc]
 [&lt;ffffffffc0225f43&gt;] fc_eh_device_reset+0x1c3/0x270 [libfc]
 [&lt;ffffffff814a2cc9&gt;] scsi_try_bus_device_reset+0x29/0x60
 [&lt;ffffffff814a3908&gt;] scsi_ioctl_reset+0x258/0x2d0
 [&lt;ffffffff814a2650&gt;] scsi_ioctl+0x150/0x440
 [&lt;ffffffff814b3a9d&gt;] sd_ioctl+0xad/0x120
 [&lt;ffffffff8132f266&gt;] blkdev_ioctl+0x1b6/0x810
 [&lt;ffffffff811da608&gt;] block_ioctl+0x38/0x40
 [&lt;ffffffff811b4e08&gt;] do_vfs_ioctl+0x2f8/0x530
 [&lt;ffffffff811b50c1&gt;] SyS_ioctl+0x81/0xa0
 [&lt;ffffffff816cf8b2&gt;] system_call_fastpath+0x16/0x7a

Signed-off-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Vasu Dev &lt;vasu.dev@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libfc: Fix fc_exch_recv_req() error path</title>
<updated>2015-08-12T18:23:30+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@sandisk.com</email>
</author>
<published>2015-06-05T21:20:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f6979adeaab578f8ca14fdd32b06ddee0d9d3314'/>
<id>f6979adeaab578f8ca14fdd32b06ddee0d9d3314</id>
<content type='text'>
Due to patch "libfc: Do not invoke the response handler after
fc_exch_done()" (commit ID 7030fd62) the lport_recv() call
in fc_exch_recv_req() is passed a dangling pointer. Avoid this
by moving the fc_frame_free() call from fc_invoke_resp() to its
callers. This patch fixes the following crash:

general protection fault: 0000 [#3] PREEMPT SMP
RIP: fc_lport_recv_req+0x72/0x280 [libfc]
Call Trace:
 fc_exch_recv+0x642/0xde0 [libfc]
 fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe]
 kthread+0x10a/0x120
 ret_from_fork+0x42/0x70

Signed-off-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Vasu Dev &lt;vasu.dev@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Due to patch "libfc: Do not invoke the response handler after
fc_exch_done()" (commit ID 7030fd62) the lport_recv() call
in fc_exch_recv_req() is passed a dangling pointer. Avoid this
by moving the fc_frame_free() call from fc_invoke_resp() to its
callers. This patch fixes the following crash:

general protection fault: 0000 [#3] PREEMPT SMP
RIP: fc_lport_recv_req+0x72/0x280 [libfc]
Call Trace:
 fc_exch_recv+0x642/0xde0 [libfc]
 fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe]
 kthread+0x10a/0x120
 ret_from_fork+0x42/0x70

Signed-off-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Vasu Dev &lt;vasu.dev@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libiscsi: Fix host busy blocking during connection teardown</title>
<updated>2015-08-12T17:21:20+00:00</updated>
<author>
<name>John Soni Jose</name>
<email>sony.john@avagotech.com</email>
</author>
<published>2015-06-24T01:11:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=660d0831d1494a6837b2f810d08b5be092c1f31d'/>
<id>660d0831d1494a6837b2f810d08b5be092c1f31d</id>
<content type='text'>
In case of hw iscsi offload, an host can have N-number of active
connections. There can be IO's running on some connections which
make host-&gt;host_busy always TRUE. Now if logout from a connection
is tried then the code gets into an infinite loop as host-&gt;host_busy
is always TRUE.

 iscsi_conn_teardown(....)
 {
   .........
    /*
     * Block until all in-progress commands for this connection
     * time out or fail.
     */
     for (;;) {
      spin_lock_irqsave(session-&gt;host-&gt;host_lock, flags);
      if (!atomic_read(&amp;session-&gt;host-&gt;host_busy)) { /* OK for ERL == 0 */
	      spin_unlock_irqrestore(session-&gt;host-&gt;host_lock, flags);
              break;
      }
     spin_unlock_irqrestore(session-&gt;host-&gt;host_lock, flags);
     msleep_interruptible(500);
     iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
                 "host_busy %d host_failed %d\n",
	          atomic_read(&amp;session-&gt;host-&gt;host_busy),
	          session-&gt;host-&gt;host_failed);

	................
	...............
     }
  }

This is not an issue with software-iscsi/iser as each cxn is a separate
host.

Fix:
Acquiring eh_mutex in iscsi_conn_teardown() before setting
session-&gt;state = ISCSI_STATE_TERMINATE.

Signed-off-by: John Soni Jose &lt;sony.john@avagotech.com&gt;
Reviewed-by: Mike Christie &lt;michaelc@cs.wisc.edu&gt;
Reviewed-by: Chris Leech &lt;cleech@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In case of hw iscsi offload, an host can have N-number of active
connections. There can be IO's running on some connections which
make host-&gt;host_busy always TRUE. Now if logout from a connection
is tried then the code gets into an infinite loop as host-&gt;host_busy
is always TRUE.

 iscsi_conn_teardown(....)
 {
   .........
    /*
     * Block until all in-progress commands for this connection
     * time out or fail.
     */
     for (;;) {
      spin_lock_irqsave(session-&gt;host-&gt;host_lock, flags);
      if (!atomic_read(&amp;session-&gt;host-&gt;host_busy)) { /* OK for ERL == 0 */
	      spin_unlock_irqrestore(session-&gt;host-&gt;host_lock, flags);
              break;
      }
     spin_unlock_irqrestore(session-&gt;host-&gt;host_lock, flags);
     msleep_interruptible(500);
     iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
                 "host_busy %d host_failed %d\n",
	          atomic_read(&amp;session-&gt;host-&gt;host_busy),
	          session-&gt;host-&gt;host_failed);

	................
	...............
     }
  }

This is not an issue with software-iscsi/iser as each cxn is a separate
host.

Fix:
Acquiring eh_mutex in iscsi_conn_teardown() before setting
session-&gt;state = ISCSI_STATE_TERMINATE.

Signed-off-by: John Soni Jose &lt;sony.john@avagotech.com&gt;
Reviewed-by: Mike Christie &lt;michaelc@cs.wisc.edu&gt;
Reviewed-by: Chris Leech &lt;cleech@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi</title>
<updated>2015-08-02T16:36:21+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-08-02T16:36:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d4edea40389d6646c760aa166103caa1f32298ed'/>
<id>d4edea40389d6646c760aa166103caa1f32298ed</id>
<content type='text'>
Pull SCSI fixes from James Bottomley:
 "A set of three fixes for the ipr driver and one fairly major one for
  memory leaks in the mq path of SCSI"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: fix memory leak with scsi-mq
  ipr: Fix invalid array indexing for HRRQ
  ipr: Fix incorrect trace indexing
  ipr: Fix locking for unit attention handling
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull SCSI fixes from James Bottomley:
 "A set of three fixes for the ipr driver and one fairly major one for
  memory leaks in the mq path of SCSI"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: fix memory leak with scsi-mq
  ipr: Fix invalid array indexing for HRRQ
  ipr: Fix incorrect trace indexing
  ipr: Fix locking for unit attention handling
</pre>
</div>
</content>
</entry>
<entry>
<title>scsi: fix memory leak with scsi-mq</title>
<updated>2015-07-30T17:40:33+00:00</updated>
<author>
<name>Tony Battersby</name>
<email>tonyb@cybernetics.com</email>
</author>
<published>2015-07-16T15:40:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0c958ecc69c277b25f38f72bc6d18ab145e8167c'/>
<id>0c958ecc69c277b25f38f72bc6d18ab145e8167c</id>
<content type='text'>
Fix a memory leak with scsi-mq triggered by commands with large data
transfer length.

__sg_alloc_table() sets both table-&gt;nents and table-&gt;orig_nents to the
same value.  When the scatterlist is DMA-mapped, table-&gt;nents is
overwritten with the (possibly smaller) size of the DMA-mapped
scatterlist, while table-&gt;orig_nents retains the original size of the
allocated scatterlist.  scsi_free_sgtable() should therefore check
orig_nents instead of nents, and all code that initializes sdb-&gt;table
without calling __sg_alloc_table() should set both nents and orig_nents.

Fixes: d285203cf647 ("scsi: add support for a blk-mq based I/O path.")
Cc: &lt;stable@vger.kernel.org&gt; # 3.17+
Signed-off-by: Tony Battersby &lt;tonyb@cybernetics.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Ewan D. Milne &lt;emilne@redhat.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix a memory leak with scsi-mq triggered by commands with large data
transfer length.

__sg_alloc_table() sets both table-&gt;nents and table-&gt;orig_nents to the
same value.  When the scatterlist is DMA-mapped, table-&gt;nents is
overwritten with the (possibly smaller) size of the DMA-mapped
scatterlist, while table-&gt;orig_nents retains the original size of the
allocated scatterlist.  scsi_free_sgtable() should therefore check
orig_nents instead of nents, and all code that initializes sdb-&gt;table
without calling __sg_alloc_table() should set both nents and orig_nents.

Fixes: d285203cf647 ("scsi: add support for a blk-mq based I/O path.")
Cc: &lt;stable@vger.kernel.org&gt; # 3.17+
Signed-off-by: Tony Battersby &lt;tonyb@cybernetics.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Ewan D. Milne &lt;emilne@redhat.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipr: Fix invalid array indexing for HRRQ</title>
<updated>2015-07-30T17:38:47+00:00</updated>
<author>
<name>Brian King</name>
<email>brking@linux.vnet.ibm.com</email>
</author>
<published>2015-07-14T16:41:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3f1c0581310d5d94bd72740231507e763a6252a4'/>
<id>3f1c0581310d5d94bd72740231507e763a6252a4</id>
<content type='text'>
Fixes another signed / unsigned array indexing bug in the ipr driver.
Currently, when hrrq_index wraps, it becomes a negative number. We
do the modulo, but still have a negative number, so we end up indexing
backwards in the array. Given where the hrrq array is located in memory,
we probably won't actually reference memory we don't own, but nonetheless
ipr is still looking at data within struct ipr_ioa_cfg and interpreting it as
struct ipr_hrr_queue data, so bad things could certainly happen.

Each ipr adapter has anywhere from 1 to 16 HRRQs. By default, we use 2 on new
adapters.  Let's take an example:

Assume ioa_cfg-&gt;hrrq_index=0x7fffffffe and ioa_cfg-&gt;hrrq_num=4:

The atomic_add_return will then return -1. We mod this with 3 and get -2, add
one and get -1 for an array index.

On adapters which support more than a single HRRQ, we dedicate HRRQ to adapter
initialization and error interrupts so that we can optimize the other queues
for fast path I/O. So all normal I/O uses HRRQ 1-15. So we want to spread the
I/O requests across those HRRQs.

With the default module parameter settings, this bug won't hit, only when
someone sets the ipr.number_of_msix parameter to a value larger than 3 is when
bad things start to happen.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes another signed / unsigned array indexing bug in the ipr driver.
Currently, when hrrq_index wraps, it becomes a negative number. We
do the modulo, but still have a negative number, so we end up indexing
backwards in the array. Given where the hrrq array is located in memory,
we probably won't actually reference memory we don't own, but nonetheless
ipr is still looking at data within struct ipr_ioa_cfg and interpreting it as
struct ipr_hrr_queue data, so bad things could certainly happen.

Each ipr adapter has anywhere from 1 to 16 HRRQs. By default, we use 2 on new
adapters.  Let's take an example:

Assume ioa_cfg-&gt;hrrq_index=0x7fffffffe and ioa_cfg-&gt;hrrq_num=4:

The atomic_add_return will then return -1. We mod this with 3 and get -2, add
one and get -1 for an array index.

On adapters which support more than a single HRRQ, we dedicate HRRQ to adapter
initialization and error interrupts so that we can optimize the other queues
for fast path I/O. So all normal I/O uses HRRQ 1-15. So we want to spread the
I/O requests across those HRRQs.

With the default module parameter settings, this bug won't hit, only when
someone sets the ipr.number_of_msix parameter to a value larger than 3 is when
bad things start to happen.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipr: Fix incorrect trace indexing</title>
<updated>2015-07-30T17:38:00+00:00</updated>
<author>
<name>Brian King</name>
<email>brking@linux.vnet.ibm.com</email>
</author>
<published>2015-07-14T16:41:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bb7c54339e6a10ecce5c4961adf5e75b3cf0af30'/>
<id>bb7c54339e6a10ecce5c4961adf5e75b3cf0af30</id>
<content type='text'>
When ipr's internal driver trace was changed to an atomic, a signed/unsigned
bug slipped in which results in us indexing backwards in our memory buffer
writing on memory that does not belong to us. This patch fixes this by removing
the modulo and instead just mask off the low bits.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When ipr's internal driver trace was changed to an atomic, a signed/unsigned
bug slipped in which results in us indexing backwards in our memory buffer
writing on memory that does not belong to us. This patch fixes this by removing
the modulo and instead just mask off the low bits.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipr: Fix locking for unit attention handling</title>
<updated>2015-07-30T17:36:21+00:00</updated>
<author>
<name>Brian King</name>
<email>brking@linux.vnet.ibm.com</email>
</author>
<published>2015-07-14T16:41:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36b8e180e1e929e00b351c3b72aab3147fc14116'/>
<id>36b8e180e1e929e00b351c3b72aab3147fc14116</id>
<content type='text'>
Make sure we have the host lock held when calling scsi_report_bus_reset. Fixes
a crash seen as the __devices list in the scsi host was changing as we were
iterating through it.

Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make sure we have the host lock held when calling scsi_report_bus_reset. Fixes
a crash seen as the __devices list in the scsi host was changing as we were
iterating through it.

Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Wen Xiong &lt;wenxiong@linux.vnet.ibm.com&gt;
Reviewed-by: Gabriel Krisman Bertazi &lt;krisman@linux.vnet.ibm.com&gt;
Signed-off-by: Brian King &lt;brking@linux.vnet.ibm.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Odin.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
