linux-toradex.git/include/linux, branch v3.2.64 Linux kernel for Apalis and Colibri modules alarmtimer: Return relative times in timer_gettime 2014-11-05T20:27:43+00:00 Richard Larocque rlarocque@google.com 2014-09-10T01:31:03+00:00 a1b01afa4324d35da3aaef069ac7220901e0e350 commit e86fea764991e00a03ff1e56409ec9cacdbda4c9 upstream. Returns the time remaining for an alarm timer, rather than the time at which it is scheduled to expire. If the timer has already expired or it is not currently scheduled, the it_value's members are set to zero. This new behavior matches that of the other posix-timers and the POSIX specifications. This is a change in user-visible behavior, and may break existing applications. Hopefully, few users rely on the old incorrect behavior. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by: Richard Larocque <rlarocque@google.com> [jstultz: minor style tweak] Signed-off-by: John Stultz <john.stultz@linaro.org> [bwh: Backported to 3.2: Add definition of alarm_expires_remaining() from commit 6cffe00f7d4e ('alarmtimer: Add functions for timerfd support')] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e86fea764991e00a03ff1e56409ec9cacdbda4c9 upstream.

Returns the time remaining for an alarm timer, rather than the time at
which it is scheduled to expire.  If the timer has already expired or it
is not currently scheduled, the it_value's members are set to zero.

This new behavior matches that of the other posix-timers and the POSIX
specifications.

This is a change in user-visible behavior, and may break existing
applications.  Hopefully, few users rely on the old incorrect behavior.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sharvil Nanavati <sharvil@google.com>
Signed-off-by: Richard Larocque <rlarocque@google.com>
[jstultz: minor style tweak]
Signed-off-by: John Stultz <john.stultz@linaro.org>
[bwh: Backported to 3.2: Add definition of alarm_expires_remaining() from
 commit 6cffe00f7d4e ('alarmtimer: Add functions for timerfd support')]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
jiffies: Fix timeval conversion to jiffies 2014-11-05T20:27:43+00:00 Andrew Hunter ahh@google.com 2014-09-04T21:17:16+00:00 d8aaaebbe614171cc12a3fe69a79315ac4e42d98 commit d78c9300c51d6ceed9f6d078d4e9366f259de28c upstream. timeval_to_jiffies tried to round a timeval up to an integral number of jiffies, but the logic for doing so was incorrect: intervals corresponding to exactly N jiffies would become N+1. This manifested itself particularly repeatedly stopping/starting an itimer: setitimer(ITIMER_PROF, &val, NULL); setitimer(ITIMER_PROF, NULL, &val); would add a full tick to val, _even if it was exactly representable in terms of jiffies_ (say, the result of a previous rounding.) Doing this repeatedly would cause unbounded growth in val. So fix the math. Here's what was wrong with the conversion: we essentially computed (eliding seconds) jiffies = usec * (NSEC_PER_USEC/TICK_NSEC) by using scaling arithmetic, which took the best approximation of NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC = x/(2^USEC_JIFFIE_SC), and computed: jiffies = (usec * x) >> USEC_JIFFIE_SC and rounded this calculation up in the intermediate form (since we can't necessarily exactly represent TICK_NSEC in usec.) But the scaling arithmetic is a (very slight) *over*approximation of the true value; that is, instead of dividing by (1 usec/ 1 jiffie), we effectively divided by (1 usec/1 jiffie)-epsilon (rounding down). This would normally be fine, but we want to round timeouts up, and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this would be fine if our division was exact, but dividing this by the slightly smaller factor was equivalent to adding just _over_ 1 to the final result (instead of just _under_ 1, as desired.) In particular, with HZ=1000, we consistently computed that 10000 usec was 11 jiffies; the same was true for any exact multiple of TICK_NSEC. We could possibly still round in the intermediate form, adding something less than 2^USEC_JIFFIE_SC - 1, but easier still is to convert usec->nsec, round in nanoseconds, and then convert using time*spec*_to_jiffies. This adds one constant multiplication, and is not observably slower in microbenchmarks on recent x86 hardware. Tested: the following program: int main() { struct itimerval zero = {{0, 0}, {0, 0}}; /* Initially set to 10 ms. */ struct itimerval initial = zero; initial.it_interval.tv_usec = 10000; setitimer(ITIMER_PROF, &initial, NULL); /* Save and restore several times. */ for (size_t i = 0; i < 10; ++i) { struct itimerval prev; setitimer(ITIMER_PROF, &zero, &prev); /* on old kernels, this goes up by TICK_USEC every iteration */ printf("previous value: %ld %ld %ld %ld\n", prev.it_interval.tv_sec, prev.it_interval.tv_usec, prev.it_value.tv_sec, prev.it_value.tv_usec); setitimer(ITIMER_PROF, &prev, NULL); } return 0; } Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Turner <pjt@google.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Paul Turner <pjt@google.com> Reported-by: Aaron Jacobs <jacobsa@google.com> Signed-off-by: Andrew Hunter <ahh@google.com> [jstultz: Tweaked to apply to 3.17-rc] Signed-off-by: John Stultz <john.stultz@linaro.org> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d78c9300c51d6ceed9f6d078d4e9366f259de28c upstream.

timeval_to_jiffies tried to round a timeval up to an integral number
of jiffies, but the logic for doing so was incorrect: intervals
corresponding to exactly N jiffies would become N+1. This manifested
itself particularly repeatedly stopping/starting an itimer:

setitimer(ITIMER_PROF, &val, NULL);
setitimer(ITIMER_PROF, NULL, &val);

would add a full tick to val, _even if it was exactly representable in
terms of jiffies_ (say, the result of a previous rounding.)  Doing
this repeatedly would cause unbounded growth in val.  So fix the math.

Here's what was wrong with the conversion: we essentially computed
(eliding seconds)

jiffies = usec  * (NSEC_PER_USEC/TICK_NSEC)

by using scaling arithmetic, which took the best approximation of
NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC =
x/(2^USEC_JIFFIE_SC), and computed:

jiffies = (usec * x) >> USEC_JIFFIE_SC

and rounded this calculation up in the intermediate form (since we
can't necessarily exactly represent TICK_NSEC in usec.) But the
scaling arithmetic is a (very slight) *over*approximation of the true
value; that is, instead of dividing by (1 usec/ 1 jiffie), we
effectively divided by (1 usec/1 jiffie)-epsilon (rounding
down). This would normally be fine, but we want to round timeouts up,
and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this
would be fine if our division was exact, but dividing this by the
slightly smaller factor was equivalent to adding just _over_ 1 to the
final result (instead of just _under_ 1, as desired.)

In particular, with HZ=1000, we consistently computed that 10000 usec
was 11 jiffies; the same was true for any exact multiple of
TICK_NSEC.

We could possibly still round in the intermediate form, adding
something less than 2^USEC_JIFFIE_SC - 1, but easier still is to
convert usec->nsec, round in nanoseconds, and then convert using
time*spec*_to_jiffies.  This adds one constant multiplication, and is
not observably slower in microbenchmarks on recent x86 hardware.

Tested: the following program:

int main() {
  struct itimerval zero = {{0, 0}, {0, 0}};
  /* Initially set to 10 ms. */
  struct itimerval initial = zero;
  initial.it_interval.tv_usec = 10000;
  setitimer(ITIMER_PROF, &initial, NULL);
  /* Save and restore several times. */
  for (size_t i = 0; i < 10; ++i) {
    struct itimerval prev;
    setitimer(ITIMER_PROF, &zero, &prev);
    /* on old kernels, this goes up by TICK_USEC every iteration */
    printf("previous value: %ld %ld %ld %ld\n",
           prev.it_interval.tv_sec, prev.it_interval.tv_usec,
           prev.it_value.tv_sec, prev.it_value.tv_usec);
    setitimer(ITIMER_PROF, &prev, NULL);
  }
    return 0;
}

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Turner <pjt@google.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Paul Turner <pjt@google.com>
Reported-by: Aaron Jacobs <jacobsa@google.com>
Signed-off-by: Andrew Hunter <ahh@google.com>
[jstultz: Tweaked to apply to 3.17-rc]
Signed-off-by: John Stultz <john.stultz@linaro.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
libceph: rename ceph_msg::front_max to front_alloc_len 2014-11-05T20:27:42+00:00 Ilya Dryomov ilya.dryomov@inktank.com 2014-01-09T18:08:21+00:00 488dbde366f437720b55cd29571219cebc89251b commit 3cea4c3071d4e55e9d7356efe9d0ebf92f0c2204 upstream. Rename front_max field of struct ceph_msg to front_alloc_len to make its purpose more clear. Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 3cea4c3071d4e55e9d7356efe9d0ebf92f0c2204 upstream.

Rename front_max field of struct ceph_msg to front_alloc_len to make
its purpose more clear.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
slab/mempolicy: always use local policy from interrupt context 2014-09-13T22:41:50+00:00 Andi Kleen ak@linux.intel.com 2012-06-09T09:40:03+00:00 1a971336c449271b091fcdb3c13d535bb04bf782 commit e7b691b085fda913830e5280ae6f724b2a63c824 upstream. slab_node() could access current->mempolicy from interrupt context. However there's a race condition during exit where the mempolicy is first freed and then the pointer zeroed. Using this from interrupts seems bogus anyways. The interrupt will interrupt a random process and therefore get a random mempolicy. Many times, this will be idle's, which noone can change. Just disable this here and always use local for slab from interrupts. I also cleaned up the callers of slab_node a bit which always passed the same argument. I believe the original mempolicy code did that in fact, so it's likely a regression. v2: send version with correct logic v3: simplify. fix typo. Reported-by: Arun Sharma <asharma@fb.com> Cc: penberg@kernel.org Cc: cl@linux.com Signed-off-by: Andi Kleen <ak@linux.intel.com> [tdmackey@twitter.com: Rework control flow based on feedback from cl@linux.com, fix logic, and cleanup current task_struct reference] Acked-by: David Rientjes <rientjes@google.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Mackey <tdmackey@twitter.com> Signed-off-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e7b691b085fda913830e5280ae6f724b2a63c824 upstream.

slab_node() could access current->mempolicy from interrupt context.
However there's a race condition during exit where the mempolicy
is first freed and then the pointer zeroed.

Using this from interrupts seems bogus anyways. The interrupt
will interrupt a random process and therefore get a random
mempolicy. Many times, this will be idle's, which noone can change.

Just disable this here and always use local for slab
from interrupts. I also cleaned up the callers of slab_node a bit
which always passed the same argument.

I believe the original mempolicy code did that in fact,
so it's likely a regression.

v2: send version with correct logic
v3: simplify. fix typo.
Reported-by: Arun Sharma <asharma@fb.com>
Cc: penberg@kernel.org
Cc: cl@linux.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
[tdmackey@twitter.com: Rework control flow based on feedback from
cl@linux.com, fix logic, and cleanup current task_struct reference]
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David Mackey <tdmackey@twitter.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mnt: Change the default remount atime from relatime to the existing value 2014-09-13T22:41:41+00:00 Eric W. Biederman ebiederm@xmission.com 2014-07-29T00:36:04+00:00 24a26ff9e1bd26f50617b0bac745141dbc226e45 commit ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e upstream. Since March 2009 the kernel has treated the state that if no MS_..ATIME flags are passed then the kernel defaults to relatime. Defaulting to relatime instead of the existing atime state during a remount is silly, and causes problems in practice for people who don't specify any MS_...ATIME flags and to get the default filesystem atime setting. Those users may encounter a permission error because the default atime setting does not work. A default that does not work and causes permission problems is ridiculous, so preserve the existing value to have a default atime setting that is always guaranteed to work. Using the default atime setting in this way is particularly interesting for applications built to run in restricted userspace environments without /proc mounted, as the existing atime mount options of a filesystem can not be read from /proc/mounts. In practice this fixes user space that uses the default atime setting on remount that are broken by the permission checks keeping less privileged users from changing more privileged users atime settings. Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [bwh: Backported to 3.2: add definition of MNT_ATIME_MASK, as we don't need the fix that introduced that definition upstream] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e upstream.

Since March 2009 the kernel has treated the state that if no
MS_..ATIME flags are passed then the kernel defaults to relatime.

Defaulting to relatime instead of the existing atime state during a
remount is silly, and causes problems in practice for people who don't
specify any MS_...ATIME flags and to get the default filesystem atime
setting.  Those users may encounter a permission error because the
default atime setting does not work.

A default that does not work and causes permission problems is
ridiculous, so preserve the existing value to have a default
atime setting that is always guaranteed to work.

Using the default atime setting in this way is particularly
interesting for applications built to run in restricted userspace
environments without /proc mounted, as the existing atime mount
options of a filesystem can not be read from /proc/mounts.

In practice this fixes user space that uses the default atime
setting on remount that are broken by the permission checks
keeping less privileged users from changing more privileged users
atime settings.

Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.2: add definition of MNT_ATIME_MASK, as we don't
 need the fix that introduced that definition upstream]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
libata: introduce ata_host->n_tags to avoid oops on SAS controllers 2014-08-06T17:07:42+00:00 Tejun Heo tj@kernel.org 2014-07-23T13:05:27+00:00 e0747c72fec37e019efffb52fc23b69457cebd27 commit 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 upstream. 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") directly used ata_port->scsi_host->can_queue from ata_qc_new() to determine the number of tags supported by the host; unfortunately, SAS controllers doing SATA don't initialize ->scsi_host leading to the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 IP: [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0 PGD 0 Oops: 0002 [#1] SMP Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000 RIP: 0010:[<ffffffff814e0618>] [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0 RSP: 0018:ffff88061a003ae8 EFLAGS: 00010012 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000 FS: 00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0 Stack: ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200 ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68 ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80 Call Trace: [<ffffffff814e96e1>] ata_sas_queuecmd+0xa1/0x430 [<ffffffffa0056ce1>] sas_queuecommand+0x191/0x220 [libsas] [<ffffffff8149afee>] scsi_dispatch_cmd+0x10e/0x300 [<ffffffff814a3bc5>] scsi_request_fn+0x2f5/0x550 [<ffffffff81317613>] __blk_run_queue+0x33/0x40 [<ffffffff8131781a>] queue_unplugged+0x2a/0x90 [<ffffffff8131ceb4>] blk_flush_plug_list+0x1b4/0x210 [<ffffffff8131d274>] blk_finish_plug+0x14/0x50 [<ffffffff8117eaa8>] __do_page_cache_readahead+0x198/0x1f0 [<ffffffff8117ee21>] force_page_cache_readahead+0x31/0x50 [<ffffffff8117ee7e>] page_cache_sync_readahead+0x3e/0x50 [<ffffffff81172ac6>] generic_file_read_iter+0x496/0x5a0 [<ffffffff81219897>] blkdev_read_iter+0x37/0x40 [<ffffffff811e307e>] new_sync_read+0x7e/0xb0 [<ffffffff811e3734>] vfs_read+0x94/0x170 [<ffffffff811e43c6>] SyS_read+0x46/0xb0 [<ffffffff811e33d1>] ? SyS_lseek+0x91/0xb0 [<ffffffff8171ee29>] system_call_fastpath+0x16/0x1b Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00 Fix it by introducing ata_host->n_tags which is initialized to ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to scsi_host_template->can_queue in ata_host_register() for !SAS ones. As SAS hosts are never registered, this will give them the same ATA_MAX_QUEUE - 1 as before. Note that we can't use scsi_host->can_queue directly for SAS hosts anyway as they can go higher than the libata maximum. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Reported-by: Jesse Brandeburg <jesse.brandeburg@gmail.com> Reported-by: Peter Hurley <peter@hurleysoftware.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") Cc: Kevin Hao <haokexin@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 upstream.

1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port->scsi_host->can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize ->scsi_host
leading to the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0
 PGD 0
 Oops: 0002 [#1] SMP
 Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm
 CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62
 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000
 RIP: 0010:[<ffffffff814e0618>]  [<ffffffff814e0618>] ata_qc_new_init+0x188/0x1b0
 RSP: 0018:ffff88061a003ae8  EFLAGS: 00010012
 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa
 RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298
 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200
 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000
 FS:  00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0
 Stack:
  ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200
  ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68
  ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80
 Call Trace:
  [<ffffffff814e96e1>] ata_sas_queuecmd+0xa1/0x430
  [<ffffffffa0056ce1>] sas_queuecommand+0x191/0x220 [libsas]
  [<ffffffff8149afee>] scsi_dispatch_cmd+0x10e/0x300
  [<ffffffff814a3bc5>] scsi_request_fn+0x2f5/0x550
  [<ffffffff81317613>] __blk_run_queue+0x33/0x40
  [<ffffffff8131781a>] queue_unplugged+0x2a/0x90
  [<ffffffff8131ceb4>] blk_flush_plug_list+0x1b4/0x210
  [<ffffffff8131d274>] blk_finish_plug+0x14/0x50
  [<ffffffff8117eaa8>] __do_page_cache_readahead+0x198/0x1f0
  [<ffffffff8117ee21>] force_page_cache_readahead+0x31/0x50
  [<ffffffff8117ee7e>] page_cache_sync_readahead+0x3e/0x50
  [<ffffffff81172ac6>] generic_file_read_iter+0x496/0x5a0
  [<ffffffff81219897>] blkdev_read_iter+0x37/0x40
  [<ffffffff811e307e>] new_sync_read+0x7e/0xb0
  [<ffffffff811e3734>] vfs_read+0x94/0x170
  [<ffffffff811e43c6>] SyS_read+0x46/0xb0
  [<ffffffff811e33d1>] ? SyS_lseek+0x91/0xb0
  [<ffffffff8171ee29>] system_call_fastpath+0x16/0x1b
 Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00

Fix it by introducing ata_host->n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template->can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before.  Note that we can't use
scsi_host->can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Reported-by: Jesse Brandeburg <jesse.brandeburg@gmail.com>
Reported-by: Peter Hurley <peter@hurleysoftware.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32")
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
introduce SIZE_MAX 2014-08-06T17:07:42+00:00 Xi Wang xi.wang@gmail.com 2012-05-31T23:26:04+00:00 b11597b7041b76aa25855db6028fad853201c54e commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream. ULONG_MAX is often used to check for integer overflow when calculating allocation size. While ULONG_MAX happens to work on most systems, there is no guarantee that `size_t' must be the same size as `long'. This patch introduces SIZE_MAX, the maximum value of `size_t', to improve portability and readability for allocation size validation. Signed-off-by: Xi Wang <xi.wang@gmail.com> Acked-by: Alex Elder <elder@dreamhost.com> Cc: David Airlie <airlied@linux.ie> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream.

ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Alex Elder <elder@dreamhost.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
include/linux/math64.h: add div64_ul() 2014-08-06T17:07:37+00:00 Alex Shi alex.shi@intel.com 2013-06-12T21:05:10+00:00 79e70e9dc0cb707ad58ce8d3ed75b50610581edd commit c2853c8df57f49620d26f317d7d43347c29bfc2e upstream. There is div64_long() to handle the s64/long division, but no mocro do u64/ul division. It is necessary in some scenarios, so add this function. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alex Shi <alex.shi@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c2853c8df57f49620d26f317d7d43347c29bfc2e upstream.

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
usb-storage/SCSI: Add broken_fua blacklist flag 2014-08-06T17:07:33+00:00 Alan Stern stern@rowland.harvard.edu 2014-06-30T15:04:21+00:00 27bbd86f9319dbeeb588b8f43fe0ac241ad336ba commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream. Some buggy JMicron USB-ATA bridges don't know how to translate the FUA bit in READs or WRITEs. This patch adds an entry in unusual_devs.h and a blacklist flag to tell the sd driver not to use FUA. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Michael Büsch <m@bues.ch> Tested-by: Michael Büsch <m@bues.ch> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: - Adjust context - Use sd_printk() not sd_first_printk()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Michael Büsch <m@bues.ch>
Tested-by: Michael Büsch <m@bues.ch>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
 - Adjust context
 - Use sd_printk() not sd_first_printk()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Revert "net: ip, ipv6: handle gso skbs in forwarding path" 2014-08-06T17:07:31+00:00 Ben Hutchings ben@decadent.org.uk 2014-07-12T20:00:54+00:00 3d4a1eea8aac05f347bbfbf41b9e2f8d6f116926 This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream. In 3.2, the transport header length is not calculated in the forwarding path, so skb_gso_network_seglen() returns an incorrect result. We also have problems due to the local_df flag not being set correctly. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which
was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.  In 3.2,
the transport header length is not calculated in the forwarding path,
so skb_gso_network_seglen() returns an incorrect result.  We also have
problems due to the local_df flag not being set correctly.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>