We can't allow the user to change multipath settings at runtime, as this
will create naming conflicts due to the different naming schemes used
for each mode.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=RVhK
-----END PGP SIGNATURE-----
Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"It's a pretty quiet round this time, which is nice. This contains:
- series from Bart, cleaning up the way we set/test/clear atomic
queue flags.
- series from Bart, fixing races between gendisk and queue
registration and removal.
- set of bcache fixes and improvements from various folks, by way of
Michael Lyle.
- set of lightnvm updates from Matias, most of it being the 1.2 to
2.0 transition.
- removal of unused DIO flags from Nikolay.
- blk-mq/sbitmap memory ordering fixes from Omar.
- divide-by-zero fix for BFQ from Paolo.
- minor documentation patches from Randy.
- timeout fix from Tejun.
- Alpha "can't write a char atomically" fix from Mikulas.
- set of NVMe fixes by way of Keith.
- bsg and bsg-lib improvements from Christoph.
- a few sed-opal fixes from Jonas.
- cdrom check-disk-change deadlock fix from Maurizio.
- various little fixes, comment fixes, etc from various folks"
* tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits)
blk-mq: Directly schedule q->timeout_work when aborting a request
blktrace: fix comment in blktrace_api.h
lightnvm: remove function name in strings
lightnvm: pblk: remove some unnecessary NULL checks
lightnvm: pblk: don't recover unwritten lines
lightnvm: pblk: implement 2.0 support
lightnvm: pblk: implement get log report chunk
lightnvm: pblk: rename ppaf* to addrf*
lightnvm: pblk: check for supported version
lightnvm: implement get log report chunk helpers
lightnvm: make address conversions depend on generic device
lightnvm: add support for 2.0 address format
lightnvm: normalize geometry nomenclature
lightnvm: complete geo structure with maxoc*
lightnvm: add shorten OCSSD version in geo
lightnvm: add minor version to generic geometry
lightnvm: simplify geometry structure
lightnvm: pblk: refactor init/exit sequences
lightnvm: Avoid validation of default op value
lightnvm: centralize permission check for lightnvm ioctl
...
namespaces_mutext is used to synchronize the operations on ctrl
namespaces list. Most of the time, it is a read operation.
On the other hand, there are many interfaces in nvme core that
need this lock, such as nvme_wait_freeze, and even more interfaces
will be added. If we use mutex here, circular dependency could be
introduced easily. For example:
context A context B
nvme_xxx nvme_xxx
hold namespaces_mutext require namespaces_mutext
sync context B
So it is better to change it from mutex to rwsem.
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch has been generated as follows:
for verb in set_unlocked clear_unlocked set clear; do
replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
$(git grep -lw queue_flag_${verb} drivers block/bsg*)
done
Except for protecting all queue flag changes with the queue lock
this patch does not change any functionality.
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit e9a48034d7.
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 <hch@lst.de>
Reported-by: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: stable@vger.kernel.org
Signed-off-by: Keith Busch <keith.busch@intel.com>
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 <baegjae@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Uses common code for determining if an error should be retried on
alternate path.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This removes nvme multipath's specific status decoding to see if failover
is needed, using the generic blk_status_t that was decoded earlier. This
abstraction from the raw NVMe status means all status decoding exists
in one place.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Trivial fix to spelling mistake in dev_warn_ratelimited message text
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When creating nvme multipath devices we should populate the 'slaves' and
'holders' directorys properly to aid userspace topology detection.
Signed-off-by: Hannes Reinecke <hare@suse.com>
[hch: split from a larger patch, compile fix for CONFIG_NVME_MULTIPATH=n]
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We do this by adding a helper that returns the ns_head for a device that
can belong to either the per-controller or per-subsystem block device
nodes, and otherwise reuse all the existing code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch adds native multipath support to the nvme driver. For each
namespace we create only single block device node, which can be used
to access that namespace through any of the controllers that refer to it.
The gendisk for each controllers path to the name space still exists
inside the kernel, but is hidden from userspace. The character device
nodes are still available on a per-controller basis. A new link from
the sysfs directory for the subsystem allows to find all controllers
for a given subsystem.
Currently we will always send I/O to the first available path, this will
be changed once the NVMe Asynchronous Namespace Access (ANA) TP is
ratified and implemented, at which point we will look at the ANA state
for each namespace. Another possibility that was prototyped is to
use the path that is closes to the submitting NUMA code, which will be
mostly interesting for PCI, but might also be useful for RDMA or FC
transports in the future. There is not plan to implement round robin
or I/O service time path selectors, as those are not scalable with
the performance rates provided by NVMe.
The multipath device will go away once all paths to it disappear,
any delay to keep it alive needs to be implemented at the controller
level.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch
Linus Torvalds
Jianchao Wang
Bart Van Assche
Christoph Hellwig
Baegjae Sung
Colin Ian King
Hannes Reinecke