scsi: libfc: Map FC_TIMED_OUT to DID_TIME_OUT

When an exchange is completed with FC_TIMED_OUT we should map it to
DID_TIME_OUT to inform the SCSI midlayer that this was a command timeout;
DID_BUS_BUSY implies that the command was never sent which is not the case
here.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231129165832.224100-4-hare@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Fix up timeout error in fc_fcp_rec_error()

We should set the status to FC_TIMED_OUT when a timeout error is passed to
fc_fcp_rec_error().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231129165832.224100-3-hare@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Don't schedule abort twice

The current FC error recovery is sending up to three REC (recovery) frames
in 10 second intervals, and as a final step sending an ABTS after 30
seconds for the command itself. Unfortunately sending an ABTS is also the
action for the SCSI abort handler, and the default timeout for SCSI
commands is also 30 seconds. This causes two ABTS to be scheduled, with the
libfc one slightly earlier. The ABTS scheduled by SCSI EH then sees the
command to be already aborted, and will always return with a 'GOOD' status
irrespective on the actual result from the first ABTS. This causes the
SCSI EH abort handler to always succeed, and SCSI EH never to be engaged.
Fix this by not issuing an ABTS when a SCSI command is present for the
exchange, but rather wait for the abort scheduled from SCSI EH. And warn
if an abort is already scheduled to avoid similar errors in the future.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231129165832.224100-2-hare@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fcoe: Use per-CPU API to update per-CPU statistics

The per-CPU statistics (struct fc_stats) is updated by getting a stable
per-CPU pointer via get_cpu() + per_cpu_ptr() and then performing the
increment. This can be optimized by using this_cpu_*() which will do
whatever is needed on the architecture to perform the update safe and
efficient. The read out of the individual value (fc_get_host_stats())
should be done by using READ_ONCE() instead of a plain-C access. The
difference is that READ_ONCE() will always perform a single access while
the plain-C access can be split by the compiler into two loads if it
appears beneficial. The usage of u64 has the side-effect that it is also
64bit wide on 32bit architectures and the read is always split into two
loads. The can lead to strange values if the read happens during an update
which alters both 32bit parts of the 64bit value. This can be circumvented
by either using a 32bit variables on 32bit architecures or extending the
statistics with a sequence counter.

Use this_cpu_*() API to update the statistics and READ_ONCE() to read it.

Link: https://lore.kernel.org/r/20220506105758.283887-3-bigeasy@linutronix.de
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Stop using the SCSI pointer

Move the fc_fcp_pkt pointer, the residual length and the SCSI status into
the new data structure libfc_cmd_priv. This patch prepares for removal of
the SCSI pointer from struct scsi_cmnd.

The user of the libfc data path functions have been identified as follows:
$ git grep -lw fc_queuecommand | grep -v scsi/libfc/
drivers/scsi/fcoe/fcoe.c

Link: https://lore.kernel.org/r/20220218195117.25689-28-bvanassche@acm.org
Cc: Saurav Kashyap <skashyap@marvell.com>
Cc: Javed Hasan <jhasan@marvell.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-44-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Fix misspelling of fc_fcp_destroy()

Fixes the following W=1 kernel build warning(s):

drivers/scsi/libfc/fc_fcp.c:2255: warning: expecting prototype for fc_fcp_destory(). Prototype was for fc_fcp_destroy() instead

Link: https://lore.kernel.org/r/20210312094738.2207817-8-lee.jones@linaro.org
Cc: Hannes Reinecke <hare@suse.de>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Move scsi/fc_encode.h to libfc

Most of this file is only used inside of libfc, so move it to where it is
actually used, with only fc_fill_fc_hdr() left inside of the header.

Link: https://lore.kernel.org/r/20201026160705.3706396-1-arnd@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

scsi: libfc: Provide missing and repair existing function documentation

Mostly due to descriptions not keeping up with API changes.

Fixes the following W=1 kernel build warning(s):

drivers/scsi/libfc/fc_fcp.c:299: warning: Function parameter or member 'status_code' not described in 'fc_fcp_retry_cmd'
drivers/scsi/libfc/fc_fcp.c:595: warning: Function parameter or member 'seq' not described in 'fc_fcp_send_data'
drivers/scsi/libfc/fc_fcp.c:595: warning: Excess function parameter 'sp' description in 'fc_fcp_send_data'
drivers/scsi/libfc/fc_fcp.c:1289: warning: Function parameter or member 't' not described in 'fc_lun_reset_send'
drivers/scsi/libfc/fc_fcp.c:1289: warning: Excess function parameter 'data' description in 'fc_lun_reset_send'
drivers/scsi/libfc/fc_fcp.c:1422: warning: Function parameter or member 't' not described in 'fc_fcp_timeout'
drivers/scsi/libfc/fc_fcp.c:1422: warning: Excess function parameter 'data' description in 'fc_fcp_timeout'
drivers/scsi/libfc/fc_fcp.c:1696: warning: Function parameter or member 'code' not described in 'fc_fcp_recovery'
drivers/scsi/libfc/fc_fcp.c:1716: warning: Function parameter or member 'offset' not described in 'fc_fcp_srr'
drivers/scsi/libfc/fc_fcp.c:1859: warning: Function parameter or member 'sc_cmd' not described in 'fc_queuecommand'
drivers/scsi/libfc/fc_fcp.c:1859: warning: Excess function parameter 'cmd' description in 'fc_queuecommand'

Link: https://lore.kernel.org/r/20200713074645.126138-13-lee.jones@linaro.org
Cc: Hannes Reinecke <hare@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin st fifth floor boston ma 02110
1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: libfc: switch to SPDX tags

Use the the GPLv2 SPDX tag instead of verbose boilerplate text.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: remove set but not used variable 'rpriv'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/libfc/fc_fcp.c: In function 'fc_queuecommand':
drivers/scsi/libfc/fc_fcp.c:1875:30: warning:
variable 'rpriv' set but not used [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: remove unnecessary condition check

kmem_cache_destroy() can handle NULL pointer correctly, so there is no
need to check NULL pointer before calling kmem_cache_destroy()

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts

With all callbacks converted, and the timer callback prototype
switched over, the TIMER_FUNC_TYPE cast is no longer needed,
so remove it. Conversion was done with the following scripts:

perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \
$(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u)

perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \
$(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u)

The now unused macros are also dropped from include/linux/timer.h.

Signed-off-by: Kees Cook <keescook@chromium.org>

scsi: libfc: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. This removes several redundant setup
calls in favor of just changing the timer function directly.

Cc: Johannes Thumshirn <jth@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: fcoe-devel@open-fcoe.org
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>

scsi: fc_fcp: do not call fc_block_scsi_eh() from host reset

When calling host reset we're resetting all ports anyway, so there is no
point in waiting for the ports to become unblocked.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: do not flood console with messages 'libfc: queue full ...'

When the FCoE sending side becomes congested libfc tries to reduce the
queue depth on the host; however due to the built-in lag before
attempting to ramp down the queue depth _again_ the message log is
flooded with the following message:

libfc: queue full, reducing can_queue to 512

With this patch the message is printed only once (ie when it's
actually changed).

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: convert fc_fcp_pkt.ref_cnt from atomic_t to refcount_t

refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter. This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_start_next callback with function call

The ->seq_start_next callback only ever had one implementation,
so call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->exch_done callback with function call

The ->exch_done callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_exch_abort callback with function call

The ->seq_exch_abort callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_send callback with function call

The ->seq_send callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->exch_seq_send callback with function call

The ->exch_seq_send callback only ever had one implementation,
so we can call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->lport_reset callback with function call

The ->lport_reset callback only ever had one implementation,
which already is exported. So remove it and use the function
directly.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: wait for E_D_TOV when out-of-order sequence is received

When detecting an out-of-order sequence we should be waiting for
E_D_TOV before trying to abort the sequence.
The response might still be stuck in the queue somewhere.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: reset timeout on queue full

When we're receiving a timeout we should be checking for queue
full status; if there are still some packets pending we should
be resetting the counter to ensure we're not missing out any
packets which are still queued.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: don't fail sequence abort for completed exchanges

If a sequence should be aborted the exchange might already
be completed (eg if the response is still queued in the rx
queue), so this shouldn't considered as an error.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: quarantine timed out xids

When a sequence times out we have no idea what happened to the
frame. And we do not know if we will ever receive the frame.
Hence we cannot re-use the xid as we would risk data corruption
if the xid had been re-used and the timed out frame would be
received after that.
So we need to quarantine the xid until the lport is reset.
Yes, I know this will (eventually) deplete the xid pool.
But for now it's the safest method.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Clarify ramp-down messages

When the queue depth is reduced we should print out the reason
for this; it might be due to a queue full condition.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: do not overwrite DID_TIME_OUT status

When a command is aborted it might already have the DID_TIME_OUT
status set, so we shouldn't be overwriting that.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: sanitize E_D_TOV and R_A_TOV setting

When setting the FCP timeout we need to ensure a lower boundary
for E_D_TOV and R_A_TOV, otherwise we'd be getting spurious I/O
issues due to the fcp timer firing too early.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: spurious I/O error under high load

If a command times out libfc is sending an REC, which also
might fail (due to frames being lost or something).
If no data has been transferred we can simply retry
the command, but the current code sets a state of FC_ERROR,
which then is being translated into DID_ERROR, resulting
in an I/O error.
So to handle this properly we need to set a separate
state FC_TRANS_RESET and mapping it onto DID_SOFT_RETRY.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: additional debugging messages

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libfc: Fix fc_fcp_cleanup_each_cmd()

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

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

libfc: Fix a typo in a source code comment

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: avoid ->change_queue_depth indirection for queue full tracking

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq. This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: provide a generic change_queue_type method

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

fcp: Do not interpret check condition as underrun

This patch avoids that the FCoE initiator sends a REC message after
having received a SCSI response with non-zero status and non-zero
DATA IN buffer length.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

treewide: relase -> release

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

libfc: fix REC handling

Currently fc_fcp_timeout doesn't check FC_RP_FLAGS_REC_SUPPORTED
flag first, this prevents REC request ever going out at all
to the target having REC support. So this patches fixes the
fc_fcp_timeout by checking FC_RP_FLAGS_REC_SUPPORTED flag first.

The changed order won't cause any issue during clearing
FC_RP_FLAGS_REC_SUPPORTED on failed IO with target not supporting
FC_RP_FLAGS_REC_SUPPORTED, since retry on failed IO would succeed.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

[SCSI] libfc: fix lun reset failure bugs in fc_fcp_resp handling of FCP_RSP_INFO

In LUN RESET testing involving NetApp targets, it is observed that LUN
RESET is failing. The fc_fcp_resp() is not completing the completion
for the LUN RESET task since fc_fcp_resp assumes that the FCP_RSP_INFO
is 8 bytes with the 4 byte reserved field, where in case of NetApp targets
the FCP_RSP to LUN RESET only has 4 bytes of FCP_RSP_INFO. This leads
fc_fcp_resp to error out w/o completing the task completion, eventually
causing LUN RESET to be escalated to host reset, which is not very nice.

Per FCP-3 r04, clause 9.5.15 and Table 23, the FCP_RSP_INFO field can be either
4 bytes or 8 bytes, with the last 4 bytes as "Reserved (if any)". Therefore it
is valid to have 4 bytes FCP_RSP_INFO like some of the NetApp targets behave.
Fixing this by validating the FCP_RSP_INFO against both the two spec allowed
length.

Reported-by: Frank Zhang <frank_1.zhang@intel.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: fix sending REC after FCP_RESP is received

This is exposed in the case the FCP_DATA frames somehow got lost and fc_fcp got
the FCP_RSP, in fc_fcp_recv_resp(), since xfer_len is less than the expected_len
it resets the the timer to wait to 2 more jiffies in case the data frames are
already queued locally. However, for target does not support REC, it would just
send RJT w/ ELS_RJT_UNSUP. The rec response handler thus only clears the rport
flag for not doing REC later, but does not do fcp_io_complete() on the
associated fsp.

The fix is just check status of FCP_RSP being received already, i.e. using the
FC_SRB_RCV_STATUS flag, in fc_fcp_timeout before start sending REC. We should
have waited long enough if there is truely data frames queued locally.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: adds FCP failures stats

Adds stats to track FCP pkt and frame alloc
failure.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc, fcoe, bnx2fc: cleanup fcoe_dev_stats

The libfc is used by fcoe but fcoe agnostic,
and therefore should not have any fcoe references.

So renaming fcoe_dev_stats from libfc as its for fc_stats.
After that libfc is fcoe string free except some strings for
Open-FCoE.org.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Acked-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>

scsi: Use struct scsi_lun in fc/fcp.h

This allows us to use scsilun_to_int without an ugly cast.

Fix up places that use scsilun_to_int on fcp->fc_lun accordingly.

In fc target, this leaves ft_cmd.lun unused, so remove it.

Signed-off-by: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kiran Patil <kiran.patil@intel.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

[SCSI] libfc: remove redundant timer init for fcp

The fcp timer is already initialized when it gets allocated.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: cache align struct fc_fcp_pkt fields

Re-arrange its fields to avoid padding and have better
cacheline alignments.

Removed not used start_time, end_time and last_pkt_time
fields.

This all reduced this struct size to 448 from 480 and
that also reduced one cacheline on x86_64 beside
eliminating 8 pads. However kept logical fields together.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: block SCSI eh thread for blocked rports

Call fc_block_scsi_eh() in all fcoe eh to blocks
the scsi_eh thread for blocked rports.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Reviewed-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: Remove the reference to FCP packet from scsi_cmnd in case of error

fc_queuecommand() allocates an FCP packet for each SCSI command and sends
it out on the wire. In the process it stores the reference to the FCP packet
in the scsi_cmnd structure.
Now, in case under stress testing the libfc exchange layer runs out of
exchanges the fc_queuecommand() may not be able to send out commands out on
the wire. In such a scenario if there is an error in sending the FCP packet
out the wire; fc_queuecommand() deletes the FCP packet from internal queue,
releases the FCP packet and returns a SCSI_MLQUEUE_HOST_BUSY status to the
scsi-ml. But, the reference to the FCP packet set in the scsi_cmnd is not
removed from the scsi_cmnd in this code path.

This might lead to a crash under stress testing where the scsi_cmnd failed by
fc_queuecommand() comes up to fc_eh_abort() via scsi eh thread. fc_eh_abort()
will get reference to the FCP packet to be aborted from the scsi_cmnd for
further FCP abort related processing and then try to release the FCP packet
that has already been released.

This patch removes the FCP packet reference from the scsi_cmnd before returning
back from fc_queuecommand() in case of an error in sending out the FCP packet.

Signed-off-by: Neerav Parikh <Neerav.Parikh@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: cleanup sending SRR request

The variable on stack, namely cdb_op, is not used but removed.

[ Patch reworked by Robert Love due to invalid patch format ]

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: two minor changes in comments

One change is to cleanup typo in comment for fc_fcp_recv(), another corrects
the misleading comment for fc_fcp_abts_resp().

[ Patch reworked by Robert Love due to invalid patch format ]

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: use FC_MAX_ERROR_CNT

Though defined, FC_MAX_ERROR_CNT is not used. It is used now for CRC error in
the path of receiving FCP frame.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: do not immediately retry the cmd when seq_send fails in fc_fcp_send_data

Currently, when seq_send() fails in fc_fcp_send_data(),
fc_fcp_retry_cmd() would complete this failed I/O directly and let
scsi-ml retry. However, target side is not notified which may hang the
target. Instead, we should just bail out from from fc_fcp_send_data
and let scsi-ml times it out and aborts this I/O instead.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

[SCSI] libfc: fix race in SRR response

In this case fsp was freed before error handler was invoked,
this is fixed by having SRR fsp reference freed by exch
destructor so that fsp will be always held until it exch
is freed.

Also don't reset fsp->recov_seq since this is needed by
SRR error handler to do exch done.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

[SCSI] libfc: release DDP context if frame_send() fails

In case frame_send() fails, make sure to let the underlying HW release the DDP
context that has already been set up before calling frame_send().

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

[SCSI] libfc: rec tov value and REC_TOV_CONST units usages is incorrect

Added REC_TOV_CONST intent was to have rec tov as e_d_tov + 1s
but currently it is e_d_tov + 1ms since e_d_tov is stored in ms
unit.

Also returned rec tov by get_fsp_rec_tov is in ms and this ms tov
is used as-is with fc_fcp_timer_set expecting jiffies tov.

Fixed this by having get_fsp_rec_tov return rec tov in jiffies
as e_d_tov + 1s and then use jiffies tov w/ fc_fcp_timer_set.

Also some cleanup, no need to cache get_fsp_rec_tov return value
in local rec_tov at various places.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Move host_lock usage into ramp_up/down routines

The host_lock is still used to protect the can_queue
value in the Scsi_Host, but it doesn't need to be held
and released by each caller. This patch moves the lock
usage into the fc_fcp_can_queue_ramp_up and
fc_fcp_can_queue_ramp_down routines.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

[SCSI] libfc: Remove usage of the Scsi_Host's host_lock

This patch removes the use of the Scsi_Host's host_lock
within fc_queuecommand. It also removes the DEF_SCSI_QCMD
usage so that libfc has fully moved on to the new
queuecommand interface.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Reviewed-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix sparse static and non-ANSI warnings

Fix sparse warning for non-ANSI function declaration.
Declare workqueue structs as static.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Robert Love <robert.w.love@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc:prevent dereferencing ERR_PTR in fc_tm_done()

If we goto out, then it tries to call kfree_skb() on an ERR_PTR which
will oops. Just return directly.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Return a valid return code in fc_fcp_pkt_abort()

Here ticks_left is added to record the result of
wait_for_completion_timeout().

[ Patch title and description edited by Robert Love
to make it more descriptive ]

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: always initialize the FCoE DDP exchange id for fsp as FC_XID_UNKNOWN

The fsp's xfer_ddp is used as indication of the exchange id for the DDPed
I/O. We should always initialize it as FC_XID_UNKNOWN for a newly allocated
fsp, otherwise the fsp allocated in fc_fcp, i.e., not from queuecommand like
LUN RESET that is not doing DDP may still think DDP is setup for it since xid
0 is valid and goes on to call fc_fcp_ddp_done() in fc_fcp_resp() from
fc_tm_done(). So, set xfer_ddp as FC_XID_UNKNOWN in fc_fcp_pkt_alloc() now.

Also removes the setting of fsp->lp as it's already done when fsp is allocated.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix statistics for FCP input/output megabytes

The statistics for InputMegabytes and OutputMegabytes are
misnamed. They're accumulating bytes, not megabytes.

The statistic returned via /sys must be in megabytes, however,
which is what the HBA-API wants. The FCP code needs to accumulate
it in bytes and then divide by 1,000,000 (not 2^20) before it
presented via sysfs.

This affects fcoe.ko only, not fnic. The fnic driver
correctly by accumulating bytes and then converts to megabytes.

I checked that libhbalinux is using the /sys file directly without
conversion.

BTW, qla2xxx does divide by 2^20, which I'm not fixing here.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix fc_tm_done not freeing the allocated fsp pkt

Frame should be freed in fc_tm_done, this is an updated patch on the one
initially submitted by Hillf Danton.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: the timeout for the REC itself is 2 * R_A_TOV_els

The timeout for the exchange carrying REC itself is 2 * R_A_TOV_els.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: do not fc_io_compl on fsp w/o any scsi_cmnd associated

Do not call fc_io_compl() on fsp w/o any scsi_cmnd, e.g., lun reset is built
inside fc_fcp, not from a scsi command from queuecommnd from scsi-ml, so in
in case target is buggy that is invalid flags in the FCP_RSP, as we have seen
in some SAN Blaze target where all bits in flags are 0, we do not want to call
io_compl on this fsp.

[ Comment block added by Robert Love ]

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: remove tgt_flags from fc_fcp_pkt struct

We can easily remove the tgt_flags from fc_fcp_pkt struct
and use rpriv->tgt_flags directly where needed.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: use rport timeout values for fcp recovery

Use the rport value for rec_tov for timeout values when
sending fcp commands. Currently, defaults are being used
which may or may not match the advertised values.

The default may cause i/o to timeout on networks that
set this value larger then the default value. To make
the timeout more configurable in the non-REC mode we
remove the FC_SCSI_ER_TIMEOUT completely allowing the
scsi-ml to do the timeout. This removes an unneeded
timer and allows the i/o timeout to be configured
using the scsi-ml knobs.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: incorrect scsi host byte codes returned to scsi-ml

The fcp packet recovery handler fc_fcp_recover() is called
when errors occurr in a fcp session. Currently it is
generically setting the status code to FC_CMD_RECOVERY for
all error types. This results in DID_BUS_BUSY errors
being returned to the scsi-ml.

DID_BUS_BUSY errors indicate "BUS stayed busy through time
out period" according to scsi.h. Many of the error reported
by fc_rcp_recovery() are pkt errors. Here we update
fc_fcp_recovery to use better host byte codes.

With certain FAST FAIL flags set DID_BUS_BUSY and DID_ERROR
will have different behaviors this was causing dm multipath
to fail quickly in some cases where a retry would be a
better action.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix stats computation in fc_queuecommand()

There seems accumulation needed.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Fix incorrect locking and unlocking in FCP

The error handler grabs the si->scsi_queue_lock, but
in the case where the fsp pointer is NULL it releases
the scsi_host lock. This can lead to a variety of
system hangs depending on which is used first- the
scsi_host lock or the scsi_queue_lock.

This patch simply unlocks the correct lock when fcp
is NULL.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tree-wide: fix comment/printk typos

"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

[SCSI] libfc: possible race could panic system due to NULL fsp->cmd

It is unlikely but in case if it hits then it would cause panic
due to null cmd ptr, so far only one instance seen recently with
ESX though this was introduced long ago with this commit:-

commit c1ecb90a66c5afc7cc5c9349f9c3714eef4a5cfb
Author: Chris Leech <christopher.leech@intel.com>
Date: Thu Dec 10 09:59:26 2009 -0800
[SCSI] libfc: reduce hold time on SCSI host lock

Currently fsp->cmd is set to NULL w/o scsi_queue_lock before
dequeuing from scsi_pkt_queue and that could cause NULL
fsp->cmd in fc_fcp_cleanup_each_cmd for cmd completing
with fsp->cmd = NULL after fc_fcp_cleanup_each_cmd taken
reference. No need to set fsp->cmd to NULL as this is also
protected by fc_fcp_lock_pkt(), for above race the
fc_fcp_lock_pkt() in fc_fcp_cleanup_each_cmd() will fail
as that cmd is already done.

Mike mentioned same issue at
http://www.open-fcoe.org/pipermail/devel/2010-September/010533.html

Similarly moved sc_cmd->SCp.ptr = NULL under scsi_queue_lock so
that scsi abort error handler won't abort on completed cmds.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: use DID_TRANSPORT_DISRUPTED while lport not ready

This is per Mile Christie feedback since in this case IO
could get retried for tape devices and therefore DID_REQUEUE
cannot be used, more details in this thread.

http://marc.info/?l=linux-scsi&m=127970522630136&w=2

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: call fc_remote_port_chkready under the host lock.

The rport port state and flags are set under the host lock,
so this patch calls fc_remote_port_chkready with the host lock
held like is also done in the other fc drivers.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: add fc_fill_reply_hdr() and fc_fill_hdr()

Add functions to fill in an FC header given a request header.
These reduces code lines in fc_lport and fc_rport and works
without an exchange/sequence assigned.

fc_fill_reply_hdr() fills a header for a final reply frame.

fc_fill_hdr() which is similar but allows specifying the
f_ctl parameter.

Add defines for F_CTL values FC_FCTL_REQ and FC_FCTL_RESP.
These can be used for most request and response sequences.

v2 of patch adds a line to copy the frame encapsulation
info from the received frame.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: IO errors on link down due to cable unplug

In this case, sync IO fails with EIO(5) errors as:-

"Thread:1 System call error:5 - Input/output error (::pwrite() failed)".

This is due to IO time out while libfc doing link down processing
to block all rports and if timed out IO was at last retry
attempt then it fails to user with EIO error followed by
these log messages.

[77848.612169] host2: rport bf0015: Delete port
[77848.612221] host2: rport e10aef: work delete
[77848.612232] host2: rport e10002: work event 3
[77848.612422] sd 2:0:1:1: [sdi] Unhandled error code
[77848.612426] sd 2:0:1:1: [sdi] Result: hostbyte=DID_ERROR
driverbyte=DRIVER_OK
[77848.612431] sd 2:0:1:1: [sdi] CDB: Write(10): 2a 00 00 00 11 20 00 00 20 00
[77848.612445] end_request: I/O error, dev sdi, sector 4384
[77848.612553] sd 2:0:1:2: [sdj] Unhandled error code

To fix these EIO errors, such timed out incomplete IOs needs
to be re-queued without counting retry attempt and this patch
does that using DID_REQUEUE scsi code.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix slowpath error from WARN_ON in fc_fcp_send_data

This is exposed by a mpio test using EMC CLARiiON targets when LUN
tresspassing happens, the burst length from the XFER_READY for the
MODE SELECT(10) is 19 bytes, much smaller than FC_MIN_MAX_PAYLOAD as
256 bytes. This patch removes the related two WARN_ON()s.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: lport state is enum not bit mask

lport state is enum not bit mask.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Move the port_id into lport

This patch creates a port_id member in struct fc_lport.
This allows libfc to just deal with fc_lport instances
instead of calling into the fc_host to get the port_id.

This change helps in only using symbols necessary for
operation from the libfc structures. libfc still needs
to change the fc_host_port_id() if the port_id changes
so the presentation layer (scsi_transport_fc) can provide
the user with the correct value, but libfc shouldn't
rely on the presentation layer for operational values.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: set both precision and field with when printing FC IDs

Most of the prints of fabric IDs were specified as %6x, which will not
print any leading 0s. It's nice to see leading 0s for identifiers
like this, which are a fixed length. This patch sets the precision
modifier as well, making the specifier %6.6x, which forces the
printing of leading 0s.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: bug in erroring out upon FCP_RSP_LEN_VAL in fc_fcp_resp

fc_fcp_resp is assuming when FCP_SNS_LEN_VAL is set, the FCP_RSP_LEN_VAL
is not, which is not true. This leads to not copying the sense data and
error out a valid FCP_RSP.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc, libfcoe, fcoe: use smp_processor_id() only when preempt disabled

When the kernel is configured for preemption, using smp_processor_id()
when preemption is enabled causes a warning backtrace and is wrong
since we could move off of that CPU as soon as we get the ID,
and we would be referencing the wrong CPU, and possibly an invalid one
if it could be hotswapped out.

Remove the fc_lport_get_stats() function and explicitly use per_cpu_ptr()
to get the statistics. Where preemption has been disabled by holding
a _bh lock continue to use smp_processor_id(), but otherwise use
get_cpu()/put_cpu().

In fcoe_recv_frame() also changed the cases where we return in the
middle to do a goto to the code which bumps ErrorFrames and does
a put_cpu(). Two of these cases didn't bump ErrorFrames before, but
doing so is harmless because they "can't happen", due to prior length
checks.

Also rearranged code in fcoe_recv_frame() to have only one call to
fc_exch_recv(). It's just as efficient and saves a call to put_cpu().

In fc_fcp.c, adjusted a FIXME comment for code which doesn't need fixing.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Add debug statements when fc_fcp returns DID_ERROR to scsi-ml

DID_ERROR cases can be ambigouos. Debugging FCP error cases
will be much easier if we have debug statements when we hit
these error conditions.

This patch simply adds debug messages using the FC_FCP_DBG
macro when we return DID_ERROR to SCSI. This way if a DID_ERROR
is reproducible turning on debug_logging will give a clue
to developers as to what the problem might be.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix fcp pkt recovery in fc_fcp_recv_data

Currently fc_fcp_recv_data calls fc_fcp_retry_cmd to
retry failed IO but in this case tgt is still sending
data frames, therefore exchange needs to be aborted
first before initiating retry. So this patch fixes
this by aborting exchange first then have retry.

Renames fc_timeout_error to fc_fcp_recovery since
fc_timeout_error is already called from several other
places beside from fcp timeout handler and then
used fc_fcp_recovery for abort & retry from
fc_fcp_recv_data, this rename also required renaming
FC_CMD_TIME_OUT status to FC_CMD_RECOVERY to be
consistent with new fc_fcp_recovery.

Data frames are not expected for an DDPed exchange and
potentially it could be tampered data frame, so does
recovery in this case by calling fc_fcp_recovery.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[SCSI] libfc: call ddp setup for only FCP reads to avoid accessing junk fsp pointer

Adds check to call fc_fcp_ddp_setup for only FCP read cmds to avoid
accessing junk fsp pointer at least in ESX since non FCP frame had
junk fsp value, though fsp is implicitly initialized to null
by __alloc_skb but with this patch no more relying on fsp
initialized to null value and hitting junk fsp ptr access.

Removes fsp pointer checking in fc_fcp_ddp_setup as this is not
needed any more since its only caller for FCP read will always
have a valid fsp.

Reported by: Frank Zhang <frank_1.zhang@intel.com>
Reported by: Rob Love <robert.w.love@intel.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: call ddp setup for only FCP reads to avoid accessing junk fsp pointer

Adds check to call fc_fcp_ddp_setup for only FCP read cmds to avoid
accessing junk fsp pointer at least in ESX since non FCP frame had
junk fsp value, though fsp is implicitly initialized to null
by __alloc_skb but with this patch no more relying on fsp
initialized to null value and hitting junk fsp ptr access.

Removes fsp pointer checking in fc_fcp_ddp_setup as this is not
needed any more since its only caller for FCP read will always
have a valid fsp.

Reported by: Frank Zhang <frank_1.zhang@intel.com>
Reported by: Rob Love <robert.w.love@intel.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

tree-wide: Assorted spelling fixes

In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

tree-wide: fix typos "ammount" -> "amount"

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

[SCSI] libfc: reduce hold time on SCSI host lock

Introduce a new lock to protect the list of fc_fcp_pkt structs in libfc
instead of using the host lock. This reduces the contention of this heavily
used lock, and I see up to a 25% performance gain in CPU bound small I/O
tests when scaling out across multiple quad-core CPUs.

The big win is in removing the host lock from the completion path
completely, as it does not need to be held around the call to scsi_done.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc, fcoe: fixes for highmem skb linearize panics

There are cases outside of our control that may result in a transmit
skb being linearized in dev_queue_xmit. There are a couple of bugs
in libfc/fcoe that can result in a panic at that point. This patch
contains two fixes to prevent those panics.

1) use fast cloning instead of shared skbs with dev_queue_xmit

dev_queue_xmit doen't want shared skbuffs being passed in, and
__skb_linearize will BUG if the skb is shared. FCoE is holding an extra
reference around the call to dev_queue_xmit, so that when it returns an
error code indicating the frame has been dropped it can maintain it's
own backlog and retransmit. Switch to using fast skb cloning for this
instead.

2) don't append compound pages as > PAGE_SIZE skb fragments

fc_fcp_send_data will append pages from a scatterlist to the nr_frags[]
if the netdev supports it. But, it's using > PAGE_SIZE compound pages
as a single skb_frag. In the highmem linearize case that page will be
passed to kmap_atomic to get a mapping to copy out of, but
kmap_atomic will only allow access to the first PAGE_SIZE part.
The memcpy will keep going and cause a page fault once is crosses the
first boundary.

If fc_fcp_send_data uses linear buffers from the start, it calls
kmap_atomic one PAGE_SIZE at a time. That same logic needs to be
applied when setting up skb_frags.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: do not use DID_NO_CONNECT for pkt alloc failures.

DID_NO_CONNECT is not a nice value to use for pkt alloc failures,
because you can probably retry and IO will become available again.
For the device reset callout, we do not want to set the scsi command
result for the above reason, and because we do not need to set
the scsi_cmd->result in this path. We and other drivers do not set it
for success for example, and we do not set it for other failure.
And scsi-ml does not send every command through this path, and it is
not expecting us to use the scsi_cmnd struct like a cmd coming thruogh
queuecommand. I think it is more for storage in case we need a cmd
struct for a tmf and to give us certain params like the LUN.

Patch was made over scsi-misc today.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: adds can_queue ramp up

Adds last_can_queue_ramp_down_time and updates this on every
ramp down. If last_can_queue_ramp_down_time is not zero then
do ramp up on any IO completion in added fc_fcp_can_queue_ramp_up.

Reset last_can_queue_ramp_down_time to zero once can_queue
is ramped up to added max_can_queue limit, this is to avoid any
more ramp up attempts on subsequent IO completion.

The ramp down and up are skipped for FC_CAN_QUEUE_PERIOD
to avoid infrequent changes to can_queue, this required
keeping track of ramp up time also in last_can_queue_ramp_up_time.

Adds code to ramp down can_queue if lp->qfull is set, with added
new ramp up code the can_queue will be increased after
FC_CAN_QUEUE_PERIOD, therefore it is safe to do ramp down
without fsp in this case and will avoid thrash. This required
fc_fcp_can_queue_ramp_down locking change so that it can be
called with Scsi_Host lock held.

Removes si->throttled and fsp state FC_SRB_NOMEM, not needed with
added ramp up code.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: reduce can_queue for all FCP frame allocation failures

Currently can_queue is reduced only if frame alloc fails
during fc_fcp_send_data but frame alloc can fail at several
other places in FCP data path and can_queue needs to be
reduced for any FCP frame alloc failure.

This patch adds fc_fcp_frame_alloc for all FCP frame allocations
and if fc_frame_alloc fails in fc_fcp_frame_alloc then reduce
can_queue in fc_fcp_frame_alloc, this will reduce can_queue for
all FCP frame alloc failures.

This required moving fc_fcp_reduce_can_queue up, to build without
adding its prototype. Also renamed fc_fcp_reduce_can_queue to
fc_fcp_can_queue_ramp_down.

Removes fc_fcp_reduce_can_queue calling from fc_fcp_recv since
not needed with added fc_fcp_frame_alloc reducing can_queue.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: use single frame allocation API

Cleans up frame allocation APIs to have just single fc_frame_alloc API.

Removes _fc_frame_alloc, renames __fc_frame_alloc to _fc_frame_alloc.

Modifies fc_fcp_send_data for removed _fc_frame_alloc, fc_fcp_send_data
was the only user of removed _fc_frame_alloc.

Also Adds check in fc_frame_alloc to do mod by 4 for only non-zero
len value.

This patch is prep work to fix can_queue reducing in next patch.
Single fc_frame_alloc API helps in fixing can_queue reducing in
next patch.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Formatting cleanups across libfc

This patch makes a variety of cleanup changes to all libfc files.

This patch adds kernel-doc headers to all functions lacking them
and attempts to better format existing headers. It also add kernel-doc
headers to structures.

This patch ensures that the current naming conventions for local ports,
remote ports and remote port private data is upheld in the following
manner.

struct instance (i.e. variable name)
--------------------------------------------------
fc_lport lport
fc_rport rport
fc_rport_libfc_priv rpriv
fc_rport_priv rdata

I also renamed dns_rp and ptp_rp to dns_rdata and ptp_rdata
respectively.

I used emacs 'indent-region' and 'tabify' on all libfc files
to correct spacing alignments.

I feel sorry for anyone attempting to review this patch.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Add routine to copy data from a buffer to a SG list

When handling the multi-frame responses of fc pass-thru requests,
a code segment similar to fc_fcp_recv_data (routine to receive
inbound SCSI data) is used in the response handler. This patch
is to add a routine, called fc_copy_buffer_to_sglist(), to handle
the common function of copying data from a buffer to a scatter-
gather list in order to avoid code duplication.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Move libfc_init and libfc_exit to fc_libfc.c

These routines are for the libfc kernel module and should be in
the libfc .c file.

Moving the libfc __init routine into fc_libfc.c caused the creation
of the fc_setup_fcp() and fc_destroy_fcp() routines so that
scsi_pkt_cachep was not exposed outside of fc_fcp.c.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Add libfc/fc_libfc.[ch] for libfc internal routines

include/scsi/libfc.h is currently loaded with common code
shared between libfc's sub-modules as well as shared between
libfc and fcoe. Previous patches attempted to move out
non-common code. This patch creates two files for common
libfc routines that will not be shared with fcoe, fnic or
any other LLDs.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Remove fc_fcp_complete

This function is never used, let's remove it.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: add queue_depth ramp up

Adjust queue_depth on fc_change_queue_depth call back
with reason SCSI_QDEPTH_RAMP_UP, no additional resource
adjustments necessary for libfc.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: fix an libfc issue with queue ramp down in libfc

The cmd_per_lun value is used by scsi-ml as fall back lowest
queue_depth value but in case of libfc cmd_per_lun is set to
same value as max queue_depth = 32.

So this patch reduces cmd_per_lun value to 3 and configures
each lun with default max queue_depth 32 in fc_slave_alloc.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: convert to scsi_track_queue_full

This converts the libfc using scsi_track_queue_full to
track the queue full from the change_queue_depth callback.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] modify change_queue_depth to take in reason why it is being called

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
Also converted pmcraid_change_queue_depth and then verified
all modules compile using "make allmodconfig" for any new build
warnings on X86_64.

Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix memory corruption caused by double frees and bad error handling

I was running into several different panics under stress, which I traced down
to a few different possible slab corruption issues in error handling paths.
I have not yet looked into why these exchange sends fail, but with these
fixes my test system is much more stable under stress than before.

fc_elsct_send() could fail and either leave the passed in frame intact
(failure in fc_ct/els_fill) or the frame could have been freed if the
failure was is fc_exch_seq_send(). The caller had no way of knowing, and
there was a potential double free in the error handling in fc_fcp_rec().

Make fc_elsct_send() always free the frame before returning, and remove the
fc_frame_free() call in fc_fcp_rec().

While fc_exch_seq_send() did always consume the frame, there were double free
bugs in the error handling of fc_fcp_cmd_send() and fc_fcp_srr() as well.

Numerous calls to error handling routines (fc_disc_error(),
fc_lport_error(), fc_rport_error_retry() ) were passing in a frame pointer that
had already been freed in the case of an error. I have changed the call
sites to pass in a NULL pointer, but there may be more appropriate error
codes to use.

Question: Why do these error routines take a frame pointer anyway? I
understand passing in a pointer encoded error to the response handlers, but
the error routines take no action on a valid pointer and should never be
called that way.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Fix frags in frame exceeding SKB_MAX_FRAGS in fc_fcp_send_data

In case of sequence offload, in fc_fcp_send_data(), the skb_fill_page_info()
called may end up adding more frags to the skb_shinfo(fp_skb(fp))->frags[],
exceeding SKB_MAX_FRAGS, this eventually corrupts the memory. I am adding the
FR_FRAME_SG_LEN back, but as SKB_MAX_FRAGS -1, leaving 1 for our fcoe_eof_crc
page. And send will be broken into multiple large sends if the frame already
contains more frags than skb handle.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Fix wrong scsi return status under FC_DATA_UNDRUN

This bug is exposed when there is a link flap in LLD. Particularly, when it
happens right after a SCSI write command is sent out, no FCP_DATA is sent,
causing fsp->status_code to be set as FC_DATA_UNDRUN in fc_fcp_complete_locked
even no SCSI status is received. Consequently, fc_io_compl treats this as DID_OK.
This results in SCSI returning successful to the initial I/O request even
there is no DATA actually sent. Particularly, if you run an I/O tool w/ data
verification on, the read back for verification is gonna fail.

This is fixed here by checking when FC_DATA_UNDRUN happens, SCSI status is
received w/ FC_SRB_RCV_STATUS set in fsp->state.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Remove unused fc_lport pointer from fc_fcp_pkt_abort

This argument isn't used, let's not pass it into the routine.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc, fcoe: Don't EXPORT_SYMBOLS unnecessarily

These are a few functions that were not used by other
modules. They did not need to be exported so this patch
removes the EXPORT_SYMBOLS call for each.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix ddp in fc_fcp for 0 xid

xid 0 was used as an indication of invalid xid before but now xid 0
can be used as a valid exchange i. This patch fixes the ddp completion
in fcp layer, i.e., in fc_fcp.c:fc_fcp_ddp_done() function, to make sure it
does not use xid 0 for indication of an invalid xid, instead, it now
uses use FC_XID_UNKNOWN for such indication.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: change elsct to use FC_ID instead of rdata

tt.elsct_send is used by both FCP and by the rport state machine.
After further patches, these two modules will use different
structures for the remote port.

So, change elsct_send to use the FC_ID instead of the fc_rport_priv
as its argument. It currently only uses the FC_ID anyway.

For CT requests the destination FC_ID is still implicitly 0xfffffc.
After further patches the did arg on CT requests will be used to
specify the FC_ID being inquired about for GPN_ID or other queries.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: make fc_rport_priv the primary rport interface.

The rport and discovery modules deal with remote ports
before fc_remote_port_add() can be done, because the
full set of rport identifiers is not known at early stages.

In preparation for splitting the fc_rport/fc_rport_priv allocation,
make fc_rport_priv the primary interface for the remote port and
discovery engines.

The FCP / SCSI layers still deal with fc_rport and
fc_rport_libfc_priv, however.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Remove page flags check for sglist

I don't believe this check is needed any more in the current kernel, which,
if I understand correctly, is for compound page where only the first page
is supposed to get ref-counted.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Remove FC_FRAME_SG_LEN in fc_fcp_send_data

FC_FRAME_SG_LEN is 4 which is too small when offload is enabled. Actually, the
WARN_ON() in fc_fcp_send_data() should be:

WARN_ON(skb_shinfo(fp_skb(fp))->nr_frags > MAX_SKB_FRAGS);

But since we will not get anything more than 64K anyway, so there is no need
to do this anyway here. Therefore, I am getting rid of FC_FRAME_SG_LEN here
and the WARN_ON here.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

libfc: Add runtime debugging with debug_logging module parameter

This patch adds the /sys/module/libfc/parameters/debug_logging
file to sysfs as a module parameter. It accepts an integer
bitmask for logging. Currently it supports:

bit
LSB 0 = general libfc debugging
1 = lport debugging
2 = disc debugging
3 = rport debugging
4 = fcp debugging
5 = EM debugging
6 = exch/seq debugging
7 = scsi logging (mostly error handling)

the other bits are not used at this time.

The patch converts all of the libfc source files to use
these new macros and removes the old FC_DBG macro.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: use DID_ERROR when we have internall aborted command

If we aborted a command, because it timed out we should not use
DID_ABORT. It will fail the command right away back to the upper
layer. We want to use something that indicated that the problem
did not complete normally, but it was not a fatal problem.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: Fix compilation warnings with allmodconfig

When building with a .config generated from 'make allmodconfig'
some build warnings are generated. This patch corrects the warnings,
adds a FC_FID_NONE (= 0) enumeration for FC-IDs and cleans up one
variable naming to meet our variable naming conventions. For example,
fc_lport's should be named "lport," not "lp."

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] fcoe, libfc: add libfcoe module

Just sets up build environment for libfcoe module towards a
libfcoe library for libfc LLDs using FCoE as libfc transport.

Common library code to libfcoe is added in next patch.

Also, updated MODULE_LICENSE from "GPL" string to "GPL v2" for
libfc, libfcoe and fcoe modules to accurately match the licenses.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] fcoe: Use per-CPU kernel function for dev_stats instead of an array

Remove the hotplug creation of dev_stats, we allocate for all possible CPUs
now when we allocate the lport.

v2: Durring the 2.6.30 merge window, before these patches were comitted,
'percpu_ptr' was renamed 'per_cpu_ptr'. This latest update updates this
patch for the name change.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: add support of large receive offload by ddp in fc_fcp

When LLD supports direct data placement (ddp) for large receive of an scsi
i/o coming into fc_fcp, we call into libfc_function_template's ddp_setup()
to prepare for a ddp of large receive for this read I/O. When I/O is complete,
we call the corresponding ddp_done() to get the length of data ddped as well
as to let LLD do clean up.

fc_fcp_ddp_setup()/fc_fcp_ddp_done() are added to setup and complete a ddped
read I/O described by the given fc_fcp_pkt. They would call into corresponding
ddp_setup/ddp_done implemented by the fcoe layer. Eventually, fcoe layer calls
into LLD's ddp_setup/ddp_done provided through net_device

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: use lso_max for sequence offload

Make sure for large send is supported by LLD in outgoing FCP data, we are only
sending the lso_max a time in one single large send, since that is what
supported by LLD.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Remove SUGGEST flags

The SUGGEST_* flags in the SCSI command result have been out of fashion
for a while and we don't actually use them in the error handling.
Remove the remaining occurrences.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc, fcoe: Fix kerneldoc comments

1) Added '()' for function names in kerneldoc comments

2) Changed comment bookends from '**/' to '*/'. The comment on the the
mailing list was that '**/' "is consistently unconventional. Not
wrong, just odd." The Documentation/kernel-doc-nano-HOWTO.txt
states that kerneldoc comment blocks should end with '**/' but most
(if not all) instance I found under drivers/scsi/ were only using
the '*/' so I converted to that style.

3) Removed incorrect linebreaks in kerneldoc comments where found

4) Removed a few unnecessary blank comment lines in kerneldoc comment
blocks

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: fixed a read IO data integrity issue when a IO data frame lost

The fc_fcp_complete_locked detected data underrun in this case and set
the FC_DATA_UNDRUN but that was ignored by fc_io_compl for all cases
including read underrun.

Added code to not to ignore FC_DATA_UNDRUN for read IO and instead
suggested scsi-ml to retry cmd to recover from lost data frame.

Not sure if it is okay to ignore FC_DATA_UNDRUN for other case, so let
code as is for other cases but removed or-ing with zero valued fsp->cdb_status
for those cases.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc, fcoe: fixed locking issues with lport->lp_mutex around lport->link_status

The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
change lport->link_status and that had these issues :-

1. The fcoe_xmit was getting called with bh disabled, thus causing
"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.

2. fc_linkup and fc_linkdown function calls lport_enter function with
lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
req. In this case grabbing the same lport->lp_mutex again in fc_puase from
fcoe_xmit would cause deadlock.

The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
FC_PAUSE bit was not used anywhere beside just setting and clear this
bit in lport->link_status, instead used a separate field qfull in fc_lport
to eliminate need for lport->lp_mutex to track pending queue full condition
and in turn avoid above described two locking issues.

Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
while lp->qfull is set.

This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
fields in fc_lport for this, this simplified all related conditional
code.

Also removed fc_pause and fc_unpause functions and instead used newly added
lport->qfull directly in fcoe.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: A modular Fibre Channel library

libFC is composed of 4 blocks supported by an exchange manager
and a framing library. The upper 4 layers are fc_lport, fc_disc,
fc_rport and fc_fcp. A LLD that uses libfc could choose to
either use libfc's block, or using the transport template
defined in libfc.h, override one or more blocks with its own
implementation.

The EM (Exchange Manager) manages exhcanges/sequences for all
commands- ELS, CT and FCP.

The framing library frames ELS and CT commands.

The fc_lport block manages the library's representation of the
host's FC enabled ports.

The fc_disc block manages discovery of targets as well as
handling changes that occur in the FC fabric (via. RSCN events).

The fc_rport block manages the library's representation of other
entities in the FC fabric. Currently the library uses this block
for targets, its peer when in point-to-point mode and the
directory server, but can be extended for other entities if
needed.

The fc_fcp block interacts with the scsi-ml and handles all
I/O.

Signed-off-by: Robert Love <robert.w.love@intel.com>
[jejb: added include of delay.h to fix ppc64 compile prob spotted by sfr]
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>