linux/drivers/nvme, branch v4.5

nvme: fix max_segments integer truncation

2016-03-03T21:43:10Z

The block layer uses an unsigned short for max_segments. The way we calculate the value for NVMe tends to generate very large 32-bit values, which after integer truncation may lead to a zero value instead of the desired outcome. Signed-off-by: Christoph Hellwig Reported-by: Jeff Lien Tested-by: Jeff Lien Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

nvme: set queue limits for the admin queue

2016-03-03T21:42:50Z

Factor out a helper to set all the device specific queue limits and apply them to the admin queue in addition to the I/O queues. Without this the command size on the admin queue is arbitrarily low, and the missing other limitations are just minefields waiting for victims. Signed-off-by: Christoph Hellwig Reported-by: Jeff Lien Tested-by: Jeff Lien Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

NVMe: Fix 0-length integrity payload

2016-03-03T21:42:50Z

A user could send a passthrough IO command with a metadata pointer to a namespace without metadata. With metadata length of 0, kmalloc returns ZERO_SIZE_PTR. Since that is not NULL, the driver would have set this as the bio's integrity payload, which causes an access fault on completion. This patch ignores the users metadata buffer if the namespace format does not support separate metadata. Reported-by: Stephen Bates Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

NVMe: Don't allow unsupported flags

2016-03-03T21:42:50Z

The command flags can change the meaning of other fields in the command that the driver is not prepared to handle. Specifically, the user could passthrough an SGL flag, causing the controller to misinterpret the PRP list the driver created, potentially corrupting memory or data. Signed-off-by: Keith Busch Reviewed-by: Jon Derrick Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

NVMe: Move error handling to failed reset handler

2016-03-03T21:42:50Z

This moves failed queue handling out of the namespace removal path and into the reset failure path, fixing a hanging condition if the controller fails or link down during del_gendisk. Previously the driver had to see the controller as degraded prior to calling del_gendisk to setup the queues to fail. But, if the controller happened to fail after this, there was no task to end outstanding requests. On failure, all namespace states are set to dead. This has capacity revalidate to 0, and ends all new requests with error status. Signed-off-by: Keith Busch Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

NVMe: Simplify device reset failure

2016-03-03T21:42:49Z

A reset failure schedules the device to unbind from the driver through the pci driver's remove. This cleans up all intialization, so there is no need to duplicate the potentially racy cleanup. To help understand why a reset failed, the status is logged with the existing warning message. Signed-off-by: Keith Busch Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

NVMe: Fix namespace removal deadlock

2016-03-03T21:42:49Z

This patch makes nvme namespace removal lockless. It is up to the caller to ensure no active namespace scanning is occuring. To ensure no scan work occurs, the nvme pci driver adds a removing state to the controller device to avoid queueing scan work during removal. The work is flushed after setting the state, so no new scan work can be queued. The lockless removal allows the driver to cleanup a namespace request_queue if the controller fails during removal. Previously this could deadlock trying to acquire the namespace mutex in order to handle such events. Signed-off-by: Keith Busch Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

NVMe: Use IDA for namespace disk naming

2016-03-03T21:42:49Z

A namespace may be detached from a controller, but a user may be holding a reference to it. Attaching a new namespace with the same NSID will create duplicate names when using the NSID to name the disk. This patch uses an IDA that is released only when the last reference is released instead of using the namespace ID. Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

NVMe: Don't unmap controller registers on reset

2016-03-03T21:42:49Z

Unmapping the registers on reset or shutdown is not necessary. Keeping the mapping simplifies reset handling. Signed-off-by: Keith Busch Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

NVMe: Rate limit nvme IO warnings

2016-02-12T15:10:31Z

We don't need to spam the kernel logs with thousands of IO cancelling messages. We can infer all IO's are being cancelled with fewer, or even none at all. This patch rate limits the message and uses the debug log level as it is mainly used for testing purposes. Signed-off-by: Keith Busch Signed-off-by: Jens Axboe