The SRP initiator allows to set max_sectors to a value that exceeds
the largest amount of data that can be mapped at once with an mlx4
HCA using fast registration and a page size of 4 KB. Hence modify
ib_map_mr_sg() such that it can map partial sg-elements. If an
sg-element has been mapped partially, let the caller know
which fraction has been mapped by adjusting *sg_offset.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Avoid that the following kernel oops occurs if memory pool
allocation fails:

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa048d0a0>] ib_drain_rq+0x0/0x20 [ib_core]
Call Trace:
 [<ffffffffa04af386>] srp_create_target+0xca6/0x13a9 [ib_srp]
 [<ffffffff813cc863>] dev_attr_store+0x13/0x20
 [<ffffffff81214b50>] sysfs_kf_write+0x40/0x50
 [<ffffffff81213f1c>] kernfs_fop_write+0x13c/0x180
 [<ffffffff81197683>] __vfs_write+0x23/0xf0
 [<ffffffff81198744>] vfs_write+0xa4/0x1a0
 [<ffffffff81199a44>] SyS_write+0x44/0xa0
 [<ffffffff8159e3e9>] entry_SYSCALL_64_fastpath+0x1c/0xac

Fixes: 1dc7b1f1 ("IB/srp: use the new CQ API")
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: NDoug Ledford <dledford@redhat.com>

If an error occurs after srp_fr_pool_get() succeeded and before the
descriptor is stored in srp_map_state (*state->fr.next++ = desc)
then srp_unmap_data() won't free the newly allocated memory
descriptor. Hence free the descriptor explicitly.

Fixes: f7f7aab1 ("IB/srp: Convert to new registration API")
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Cc: Sagi Grimberg <sai@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: NDoug Ledford <dledford@redhat.com>

pr_debug() already prints prefix PFX. Avoid that PFX is printed
twice if the debug statement in srp_add_target() is enabled.

Fixes: 34aa654e ("IB/srp: Avoid that I/O hangs due to a cable pull during LUN scanning")
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Replace the homegrown RDMA READ/WRITE code in isert with the generic API,
which also adds iWarp support to the I/O path as a side effect.  Note
that full iWarp operation will need a few additional patches from Steve.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Replace the homegrown RDMA READ/WRITE code in srpt with the generic API.
The only real twist here is that we need to allocate one Linux scatterlist
per direct buffer in the SRP command, and chain them before handing them
off to the target core.

As a side-effect of the conversion the driver will also chain the SEND
of the SRP response to the RDMA WRITE WRs for a DATA OUT command, and
properly account for RDMA WRITE WRs instead of just for RDMA READ WRs
like the driver previously did.

We now allocate half of the SQ size to RDMA READ/WRITE contexts, assuming
by default one RDMA READ or WRITE operation per command.  If a command
has multiple operations it will eat into the budget but will still succeed,
possible after waiting for WQEs to be available.

Also ensure the QPs request the maximum allowed SGEs so that RDMA R/W API
works correctly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The SRP target driver will need to allocate and chain it's own SGLs soon.
For this export target_alloc_sgl, and add a new argument to it so that it
can allocate an additional chain entry that doesn't point to a page.  Also
export transport_free_sgl after renaming it to target_free_sgl to free
these SGLs again.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This supports both manual mapping of lots of SGEs, as well as using MRs
from the QP's MR pool, for iWarp or other cases where it's more optimal.
For now, MRs are only used for iWARP transports.  The user of the RDMA-RW
API must allocate the QP MR pool as well as size the SQ accordingly.

Thanks to Steve Wise for testing, fixing and rewriting the iWarp support,
and to Sagi Grimberg for ideas, reviews and fixes.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This is the first step toward moving MR invalidation decisions
to the core.  It will be needed by the upcoming RW API.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Split the XRC magic into a separate function, and return early on failure
to make the initialization code readable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The new RW API will need this.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NSagi Grimberg <sai@grimberg.m>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Since all srp_map_finish_fr() callers pass a non-zero value as
the fourth argument (sg_nents), the sg_nents == 0 check in that
function can be removed. Add a count == 0 check in the caller
of that function.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The srp_queuecommand() function translates ENOMEM into QUEUE_FULL
which causes the SCSI mid-layer to retry the command. All other
error codes are translated into DID_ERROR which causes the SCSI
command to fail. Return E2BIG if mapping will always fail to
prevent that the SCSI mid-layer keeps resubmitting a command
forever.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This patch does not change any functionality.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Ensure that req->nmdesc is set correctly in srp_map_sg() if mapping
fails. Avoid that mapping failure causes a memory descriptor leak.
Report srp_map_sg() failure to the caller.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The free request list was removed through patch "IB/srp: Use block layer tags".
Hence update a comment that refers to that free request list.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Change one occurrence of "boundries" into "boundaries".
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use c4iw_ep_disconnect() instead.  This is part of getting rid of
abort_connection() altogether so we properly clean up on send_abort()
failures.

This is the last user of abort_connection(), so remove it too.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

In c4iw_ep_disconnect(), if we fail to initiate a close operation, then
move the qp to ERROR to disassociate the ep from the qp.  Failure to do
this will leak the ep resources.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Instead return whether the caller needs to disconnect. This is part of
getting rid of abort_connection() altogether so we properly clean up on
send_abort() failures.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use c4iw_ep_disconnect() instead. This is part of getting rid of
abort_connection() altogether so we properly clean up on send_abort()
failures.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Instead, have the caller, rx_data() handle the close/abort like
it does for process_mpa_request(). This is part of getting rid of
abort_connection() altogether so we properly clean up on send_abort()
failures.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

In rx_data(), with the ep in FPDU_MODE, refcnt=2, if we get unexpected
streaming data, we call c4iw_modify_rc_qp() and move the qp from
RTS -> TERMINATE.  In c4iw_modify_rc_qp(), if rdma_fini() returns
an error, the ep will be dereferenced (refcnt=1).  Then rx_data()
calls c4iw_ep_disconnect() which starts the close operation.
But if send_halfclose() fails in c4iw_ep_disconnect(), we  will call
release_ep_resources() derefing the ep which reduces the refcnt to 0 and
and frees the ep. However we still has the ep mutex at that point, so we
have a touch-after-free bug.  There is a similar issue where
peer_close() calls c4iw_ep_disconnect().

The solution is to add a reference to the ep in c4iw_ep_disconnect()
after acquiring  the mutex, and release it after releasing the mutex.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

In c4iw_ep_disconnect(), if we start the ep timer to begin a close,
but send_halfclose() fails, we need to stop the timer and send a CLOSE
event up to the IWCM before releasing the resources. Otherwise, we can
crash when the ep timer fires if the ep is referencing a previous instance
of the device. This can happen as part of adapter reset/recovery, for
instance.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

If ARP fails before the CPL_PASS_ACCEPT_RPL is seen by hardware, the tid
will be stuck in SYN_PEND and never released.  So create an arp failure
handler specifically for this message to release the endpoint resources.

In pass_accept_rpl_arp_failure(), put the parent endpoint so it will
be freed when destroyed.  Also we don't need to call release_tid() here
because _c4iw_free_ep() calls cxgb4_remove_tid() which releases the
hwtid.

If we get an ABORT_REQ_RSS instead of a PASS_ESTABLISH (because the
peer's ACK to our SYN is never received), then put the parent as well
in peer_abort().

Treat accept_cr() failures just like arp failures: put the parent ep
and release the ep resources destroying the tid

The ARP failure handlers are called in an atomic context, so we need to
schedule some of the processing which might block.  Namely _c4iw_free_ep()
which needs a mutex.  So create a "special" CPL opcode and handler and
schedule it via sched() to be run by process_work() in a blockable context.

Also rework the active open arp failure handler to make use of
release_ep_resources().  This allows both the active and passive arp
failure handlers to use the same deferred cleanup function.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

iSER currently has a couple places that set max_sectors in either the host
template or SCSI host, and all of them get it wrong.

This patch instead uses a single assignment that (hopefully) gets it right:
the max_sectors value must be derived from the number of segments in the
FR or FMR structure, but actually be one lower than the page size multiplied
by the number of sectors, as it has to handle the case of non-aligned I/O.

Without this I get trivial to reproduce hangs when running xfstests
(on XFS) over iSER to Linux targets.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Acked-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Alternatively one could free the skb, OTOH I don't think this test is
useful so just remove it.

Cc: <linux-rdma@vger.kernel.org>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Fix for removing a quad hash entry when the
corresponding quad hash entry hasn't been added,
which is the case in loopback connections
Signed-off-by: NTatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Fix for checking if the QP associated with a completion
has been destroyed while processing CQ elements.
If that is the case, move the CQ head to the next element
and continue completion processing.
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

A check is added to validate the requested sge number.
iWARP doesn't support multiple sg elements for
RDMA READ work requests.
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Fix to calculate the SQ size based on the max
frag_count, requested by the application instead
of overwriting it with the max supported frag_count
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Fix for filling in the WQE size for NOP
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

STag index mask is calculated incorrectly, missing
the 14 bits minimum requirement. Add max macro to use
either # of MRs or 14 bits in the mask size calculation.
Signed-off-by: NTatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Invalidation after every WQE write is changed to invalidate
only if required. NOPs are padded so that WQE writes are
aligned to 64B boundary.
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NFaisal Latif <faisal.latif@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>