For a host to access an Open-Channel SSD, it has to know its geometry,
so that it writes and reads at the appropriate device bounds.
Currently, the geometry information is kept within the kernel, and not
exported to user-space for consumption. This patch exposes the
configuration through sysfs and enables user-space libraries, such as
liblightnvm, to use the sysfs implementation to get the geometry of an
Open-Channel SSD.
The sysfs entries are stored within the device hierarchy, and can be
found using the "lightnvm" device type.
An example configuration looks like this:
/sys/class/nvme/
└── nvme0n1
├── capabilities: 3
├── device_mode: 1
├── erase_max: 1000000
├── erase_typ: 1000000
├── flash_media_type: 0
├── media_capabilities: 0x00000001
├── media_type: 0
├── multiplane: 0x00010101
├── num_blocks: 1022
├── num_channels: 1
├── num_luns: 4
├── num_pages: 64
├── num_planes: 1
├── page_size: 4096
├── prog_max: 100000
├── prog_typ: 100000
├── read_max: 10000
├── read_typ: 10000
├── sector_oob_size: 0
├── sector_size: 4096
├── media_manager: gennvm
├── ppa_format: 0x380830082808001010102008
├── vendor_opcode: 0
├── max_phys_secs: 64
└── version: 1
Signed-off-by: Simon A. F. Lund <slund@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
LightNVM compatible device drivers does not have a method to expose
LightNVM specific sysfs entries.
To enable LightNVM sysfs entries to be exposed, lightnvm device
drivers require a struct device to attach it to. To allow both the
actual device driver and lightnvm sysfs entries to coexist, the device
driver tracks the lifetime of the nvm_dev structure.
This patch refactors NVMe and null_blk to handle the lifetime of struct
nvm_dev, which eliminates the need for struct gendisk when a lightnvm
compatible device is provided.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The passed by reference ppa list in nvm_set_rqd_list() is updated when
multiple planes are available. In that case, each PPA plane is
incremented when the device side PPA list is created. This prevents the
caller to rely on the PPA list to be unmodified after a call.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The [get/put]_blk API enables targets to get ownership of blocks at
runtime. This information is currently not recorded on disk, and the
information is therefore lost on power failure. To restore the
metadata, the [get/put]_blk must persist its metadata. In that case,
we need to control the outer lock, so that we can disable them while
updating the on-disk metadata. Fortunately, the _unlocked versions can
be removed, which allows us to move the lock into the [get/put]_blk
functions.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
To enable persistent block management to easily control creation and
removal of targets, we move target management into the media
manager. The LightNVM core continues to maintain which target types are
registered, while the media manager now keeps track of its initialized
targets.
Two new callbacks for the media manager are introduced. create_tgt and
remove_tgt. Note that remove_tgt returns 0 on successfully removing a
target, and returns 1 if the target was not found.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The responsibility of the media manager is not to keep track of
open/closed blocks. This is better maintained within a target,
that already manages this information on writes.
Remove the statistics and merge the states NVM_BLK_ST_OPEN and
NVM_BLK_ST_CLOSED.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The ->reserved bit is not initialized when allocated on stack.
This may lead targets to misinterpret the PPA as cached.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Expose media manager mark_blk() to targets, as done for the rest of the
media manager callback functions.
Signed-off-by: Javier González <javier@cnexlabs.com>
Updated description
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The nvm_dev->max_pages_per_blk variable was removed in favor of the new
nvm->sec_per_blk variable. The ->max_pages_per_blk variable was still
used in rrpc_capacity, reporting the reserved capacity to zero. Replace
with ->sec_per_blk to calculate the reserved area again.
Signed-off-by: Javier González <javier@cnexlabs.com>
Updated patch description. Was "lightnvm: eliminate redundant variable"
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The number of ppas contained on a request is not necessarily the number
of pages that it maps to neither on the target nor on the device side.
In order to avoid confusion, rename nr_pages to nr_ppas since it is what
the variable actually contains.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
A target requires a method to identify PPAs that are either cached in
memory or on disk. This can efficiently be maintained within the PPA.
The target host-side translation table can then lookup a PPA and know
from the PPA if it is cached or on disk. In the case it is cached, it is
the responsibility of the target to maintain this cache.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Targets can update a block state when having a reference to an
in-memory virtual block. In the case that a target does not keep the
block metadata in memory, it does not have a way to update this
structure.
Therefore, expose gennvm_mark_blk() through the media managers
->mark_blk() callback and let targets update the state structure through
this callback.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Targets associated with a device manager are not freed on device
removal. They have to be manually removed before shutdown. Make sure
any outstanding targets are freed upon shutdown.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Until now, the dma pool have been exclusively used to allocate the ppa
list being sent to the device. In pblk (upcoming), we use these pools to
allocate metadata too. Thus, we generalize the names of some variables
on the dma helper functions to make the code more readable.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Enable metadata buffer to be sent to the device through the metadata
field on the physical rw nvme command. The size of the metadata buffer
must follow dev->oob_size * # of PPAs.
Signed-off-by: Javier González <javier@cnexlabs.com>
Updated description.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The set_bb_tbl takes struct nvm_rq and only uses its ppa_list and
nr_pages internally. Instead, make these two variables explicit.
This allows a user to call it without initializing a struct nvm_rq
first.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
A virtual block enables a block to identify multiple physical blocks.
This is useful for metadata where a device media supports multiple
planes. In that case, a block, with multiple planes can be managed
as a single vblk. Reducing the metadata required by one forth.
nvm_set_rqd_ppalist() takes care of expanding a ppa_list with vblks
automatically. However, for some use-cases, where only a single physical
block is required, the ppa_list should not be expanded.
Therefore, add a vblk parameter to nvm_set_rqd_ppalist(), and only
expand the ppa_list if vblk is set.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The device ops->get_bb_tbl() takes a callback, that allows the caller
to use its own callback function to update its data structures in the
returning function.
This makes it difficult to send parameters to the callback, and usually
is circumvented by small private structures, that both carry the callers
state and any flags needed to fulfill the update.
Refactor ops->get_bb_tbl() to fill a data buffer with the status of the
blocks returned, and let the user call the callback function manually.
That will provide the necessary flags and data structures and simplify
the logic around ops->get_bb_tbl().
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Users that wish to iterate all luns on a device. Must create a
struct ppa_addr and separate iterators for channels and luns. To set the
iterators, two loops are required, one to iterate channels, and another
to iterate luns. This leads to decrease in readability.
Introduce nvm_for_each_lun_ppa, which implements the nested loop and
sets ppa, channel, and lun variable for each loop body, eliminating
the boilerplate code.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
A target name must be unique. However, a per-device registration of
targets is maintained on a dev->online_targets list, with a per-device
search for targets upon registration.
This results in a name collision when two targets, with the same name,
are created on two different targets, where the per-device list is not
shared.
Signed-off-by: Simon A. F. Lund <slund@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The functions nvm_register_target(), nvm_unregister_target() and
associated list refers to a target type that is being registered by a
target type module. Rename nvm_*_targets() to nvm_*_tgt_type(), so that
the intension is clear.
This enables target instances to use the _nvm_*_targets() naming.
Signed-off-by: Simon A. F. Lund <slund@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The get block table command returns a list of blocks and planes
with their associated state. Users, such as gennvm and sysblk,
manages all planes as a single virtual block.
It was therefore natural to fold the bad block list before it is
returned. However, to allow users, which manages on a per-plane
block level, to also use the interface, the get_bb_tbl interface is
changed to not fold by default and instead let the caller fold if
necessary.
Reviewed by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The flash page size (fpg) and size across planes (pfpg) are convenient
to know when allocating buffer sizes. This has previously been a
calculated in various places. Replace with the pre-calculated values.
Reviewed by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
The nvm_submit_ppa function assumes that users manage all plane
blocks as a single block. Extend the API with nvm_submit_ppa_list
to allow the user to send its own ppa list. If the user submits more
than a single PPA, the user must take care to allocate and free
the corresponding ppa list.
Reviewed by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
PPAs sent to device is separately acknowledge in a 64bit status
variable. The status is stored in DW0 and DW1 of the completion queue
entry. Store this status inside the nvm_rq for further processing.
This can later be used to implement retry techniques for failed writes
and reads.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
