linux.git/drivers/nvme/host/core.c, branch v4.16

Revert "nvme: create 'slaves' and 'holders' entries for hidden controllers"

2018-03-07T10:22:28+00:00

This reverts commit e9a48034d7d1318ece7d4a235838a86c94db9d68.

The slaves and holders link for the hidden gendisks confuse lsblk so that
it errors out on, or doesn't report the nvme multipath devices.  Given
that we don't need holder relationships for something that can't even be
directly accessed we should just stop creating those links.

Signed-off-by: Christoph Hellwig 
Reported-by: Potnuri Bharat Teja 
Cc: stable@vger.kernel.org
Signed-off-by: Keith Busch

Merge branch 'for-jens' of git://git.infradead.org/nvme into for-linus

2018-02-28T19:18:58+00:00

Pull NVMe fixes from Keith for 4.16-rc.

* 'for-jens' of git://git.infradead.org/nvme:
  nvmet: fix PSDT field check in command format
  nvme-multipath: fix sysfs dangerously created links
  nvme-pci: Fix nvme queue cleanup if IRQ setup fails
  nvmet-loop: use blk_rq_payload_bytes for sgl selection
  nvme-rdma: use blk_rq_payload_bytes instead of blk_rq_bytes
  nvme-fabrics: don't check for non-NULL module in nvmf_register_transport

nvme-multipath: fix sysfs dangerously created links

2018-02-28T09:46:48+00:00

If multipathing is enabled, each NVMe subsystem creates a head
namespace (e.g., nvme0n1) and multiple private namespaces
(e.g., nvme0c0n1 and nvme0c1n1) in sysfs. When creating links for
private namespaces, links of head namespace are used, so the
namespace creation order must be followed (e.g., nvme0n1 ->
nvme0c1n1). If the order is not followed, links of sysfs will be
incomplete or kernel panic will occur.

The kernel panic was:
  kernel BUG at fs/sysfs/symlink.c:27!
  Call Trace:
    nvme_mpath_add_disk_links+0x5d/0x80 [nvme_core]
    nvme_validate_ns+0x5c2/0x850 [nvme_core]
    nvme_scan_work+0x1af/0x2d0 [nvme_core]

Correct order
Context A     Context B
nvme0n1
nvme0c0n1     nvme0c1n1

Incorrect order
Context A     Context B
              nvme0c1n1
nvme0n1
nvme0c0n1

The nvme_mpath_add_disk (for creating head namespace) is called
just before the nvme_mpath_add_disk_links (for creating private
namespaces). In nvme_mpath_add_disk, the first context acquires
the lock of subsystem and creates a head namespace, and other
contexts do nothing by checking GENHD_FL_UP of a head namespace
after waiting to acquire the lock. We verified the code with or
without multipathing using three vendors of dual-port NVMe SSDs.

Signed-off-by: Baegjae Sung 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Keith Busch

nvme-rdma: fix sysfs invoked reset_ctrl error flow

2018-02-14T13:44:22+00:00

When reset_controller that is invoked by sysfs fails,
it enters an error flow which practically removes the
nvme ctrl entirely (similar to delete_ctrl flow). It
causes the system to hang, since a sysfs attribute cannot
be unregistered by one of its own methods.

This can be fixed by calling delete_ctrl as a work rather
than sequential code. In addition, it should give the ctrl
a chance to recover using reconnection mechanism (consistant
with FC reset_ctrl error flow). Also, while we're here, return
suitable errno in case the reset ended with non live ctrl.

Signed-off-by: Nitzan Carmi 
Reviewed-by: Max Gurtovoy 
Signed-off-by: Sagi Grimberg

nvme: fix the deadlock in nvme_update_formats

2018-02-14T00:09:50+00:00

nvme_update_formats will invoke nvme_ns_remove under namespaces_mutext.
The will cause deadlock because nvme_ns_remove will also require
the namespaces_mutext. Fix it by getting the ns entries which should
be removed under namespaces_mutext and invoke nvme_ns_remove out of
namespaces_mutext.

Signed-off-by: Jianchao Wang 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Keith Busch 
Signed-off-by: Sagi Grimberg

nvme: Don't use a stack buffer for keep-alive command

2018-02-12T20:18:14+00:00

In nvme_keep_alive() we pass a request with a pointer to an NVMe command on
the stack into blk_execute_rq_nowait().  However, the block layer doesn't
guarantee that the request is fully queued before blk_execute_rq_nowait()
returns.  If not, and the request is queued after nvme_keep_alive() returns,
then we'll end up using stack memory that might have been overwritten to
form the NVMe command we pass to hardware.

Fix this by keeping a special command struct in the nvme_ctrl struct right
next to the delayed work struct used for keep-alives.

Signed-off-by: Roland Dreier 
Signed-off-by: Sagi Grimberg

nvme: Fix discard buffer overrun

2018-02-08T16:35:55+00:00

This patch checks the discard range array bounds before setting it in
case the driver gets a badly formed request.

Signed-off-by: Keith Busch 
Reviewed-by: Jens Axboe 
Signed-off-by: Sagi Grimberg

nvme: delete NVME_CTRL_LIVE --> NVME_CTRL_CONNECTING transition

2018-02-08T16:35:54+00:00

There is no logical reason to move from live state to connecting
state. In case of initial connection establishment, the transition
should be NVME_CTRL_NEW --> NVME_CTRL_CONNECTING --> NVME_CTRL_LIVE.
In case of error recovery or reset, the transition should be
NVME_CTRL_LIVE --> NVME_CTRL_RESETTING --> NVME_CTRL_CONNECTING -->
NVME_CTRL_LIVE.

Signed-off-by: Max Gurtovoy 
Reviewed-by: James Smart 
Signed-off-by: Sagi Grimberg

nvme-rdma: use NVME_CTRL_CONNECTING state to mark init process

2018-02-08T16:35:53+00:00

In order to avoid concurrent error recovery during initialization
process (allowed by the NVME_CTRL_NEW --> NVME_CTRL_RESETTING transition)
we must mark the ctrl as CONNECTING before initial connection
establisment.

Signed-off-by: Max Gurtovoy 
Reviewed-by: James Smart 
Signed-off-by: Sagi Grimberg

nvme: rename NVME_CTRL_RECONNECTING state to NVME_CTRL_CONNECTING

2018-02-08T16:35:53+00:00

In pci transport, this state is used to mark the initialization
process. This should be also used in other transports as well.

Signed-off-by: Max Gurtovoy 
Reviewed-by: James Smart 
Signed-off-by: Sagi Grimberg