tcm_fc: Fix crash seen with aborts and large reads

This patch fixes a crash seen when large reads have their exchange
aborted by either timing out or being reset. Because the exchange
abort results in the seq pointer being set to NULL, because the
sequence is no longer valid, it must not be dereferenced. This
patch changes the function ft_get_task_tag to return ~0 if it is
unable to get the tag for this reason. Because the get_task_tag
interface provides no means of returning an error, this seems
like the best way to fix this issue at the moment.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target: Clean up returning errors in PR handling code

 - instead of (PTR_ERR(file) < 0) just use IS_ERR(file)
 - return -EINVAL instead of EINVAL
 - all other error returns in target_scsi3_emulate_pr_out() use
   "goto out" -- get rid of the one remaining straight "return."

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
target: Fix range calculation in WRITE SAME emulation when num blocks == 0

When NUMBER OF LOGICAL BLOCKS is 0, WRITE SAME is supposed to write
all the blocks from the specified LBA through the end of the device.
However, dev->transport->get_blocks(dev) (perhaps confusingly) returns
the last valid LBA rather than the number of blocks, so the correct
number of blocks to write starting with lba is

dev->transport->get_blocks(dev) - lba + 1

(nab: Backport roland's for-3.6 patch to for-3.5)

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Make wait_for_device_probe() also do scsi_complete_async_scans()

Commit a7a20d103994 ("sd: limit the scope of the async probe domain")
make the SCSI device probing run device discovery in it's own async
domain.

However, as a result, the partition detection was no longer synchronized
by async_synchronize_full() (which, despite the name, only synchronizes
the global async space, not all of them).  Which in turn meant that
"wait_for_device_probe()" would not wait for the SCSI partitions to be
parsed.

And "wait_for_device_probe()" was what the boot time init code relied on
for mounting the root filesystem.

Now, most people never noticed this, because not only is it
timing-dependent, but modern distributions all use initrd.  So the root
filesystem isn't actually on a disk at all.  And then before they
actually mount the final disk filesystem, they will have loaded the
scsi-wait-scan module, which not only does the expected
wait_for_device_probe(), but also does scsi_complete_async_scans().

[ Side note: scsi_complete_async_scans() had also been partially broken,
  but that was fixed in commit 43a8d39d0137 ("fix async probe
  regression"), so that same commit a7a20d103994 had actually broken
  setups even if you used scsi-wait-scan explicitly ]

Solve this problem by just moving the scsi_complete_async_scans() call
into wait_for_device_probe().  Everybody who wants to wait for device
probing to finish really wants the SCSI probing to complete, so there's
no reason not to do this.

So now "wait_for_device_probe()" really does what the name implies, and
properly waits for device probing to finish.  This also removes the now
unnecessary extra calls to scsi_complete_async_scans().

Reported-and-tested-by: Artem S. Tashkinov <t.artem@mailcity.com>
Cc: Dan Williams <dan.j.williams@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: linux-scsi <linux-scsi@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mips: fix bug.h build regression

Commit 377780887 ("bug.h: need linux/kernel.h for TAINT_WARN.") broke
all MIPS builds:

    CC      arch/mips/kernel/machine_kexec.o
  include/linux/log2.h: In function '__ilog2_u32':
  include/linux/log2.h:34:2: error: implicit declaration of function 'fls' [-Werror=implicit-function-declaration]
  include/linux/log2.h: In function '__ilog2_u64':
  include/linux/log2.h:42:2: error: implicit declaration of function 'fls64' [-Werror=implicit-function-declaration]
  ...

Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org>
Tested-by: John Crispin <blogic@openwrt.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kexec: update URL of kexec homepage

The referenced html file does not exist anymore. Replace the URL with
the current project homepage.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull target fixes from Nicholas Bellinger:
 "This includes a bugfix from MDR to address a NULL pointer OOPs with
  FCoE aborts, along with a WRITE_SAME emulation bugfix for NOLB=0
  cases, and persistent reservation return cleanups from Roland.

  All three patches are CC'ed to stable."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: Fix range calculation in WRITE SAME emulation when num blocks == 0
  target: Clean up returning errors in PR handling code
  tcm_fc: Fix crash seen with aborts and large reads