Dennis Zhou [Sat, 20 Oct 2018 18:56:12 +0000 (14:56 -0400)]
blkcg: reassociate bios when make_request() is called recursively
When submitting a bio, multiple recursive calls to make_request() may
occur. This causes the initial associate done in blkcg_bio_issue_check()
to be incorrect and reference the prior request_queue. This introduces
a helper to do reassociation when make_request() is recursively called.
Fixes: a7b39b4e961c ("blkcg: always associate a bio with a blkg") Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Dennis Zhou <dennis@kernel.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Dennis Zhou [Sat, 20 Oct 2018 18:56:11 +0000 (14:56 -0400)]
blkcg: fix edge case for blk_get_rl() under memory pressure
It is possible for blkg creation to fail when in blk_get_rl(). In this
situation, the fallback logic returns the nearest created blkg. There is
however special handling for the request_list for the root blkcg. This
fixes the missing edge case from the earlier series changing
blk_get_rl().
Fixes: e2b0989954ae ("blkcg: cleanup and make blk_get_rl use blkg_lookup_create") Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Fri, 19 Oct 2018 15:47:19 +0000 (09:47 -0600)]
Merge branch 'nvme-4.20' of git://git.infradead.org/nvme into for-4.20/block
Pull NVMe updates from Christoph:
"The second batch of updates for Linux 4.20:
- lot of fixes for issues found by static type checkers from Bart
- two small fixes from Keith
- fabrics cleanups in preparation of the TCP transport from Sagi
- more cleanups from Chaitanya"
* 'nvme-4.20' of git://git.infradead.org/nvme:
nvme-fabrics: move controller options matching to fabrics
nvme-rdma: always have a valid trsvcid
nvme-pci: remove duplicate check
nvme-pci: fix hot removal during error handling
nvmet-fcloop: suppress a compiler warning
nvme-core: make implicit seed truncation explicit
nvmet-fc: fix kernel-doc headers
nvme-fc: rework the request initialization code
nvme-fc: introduce struct nvme_fcp_op_w_sgl
nvme-fc: fix kernel-doc headers
nvmet: avoid integer overflow in the discard code
nvmet-rdma: declare local symbols static
nvmet: use strlcpy() instead of strcpy()
nvme-pci: fix nvme_suspend_queue() kernel-doc header
nvme-core: rework a NQN copying operation
nvme-core: declare local symbols static
nvmet-rdma: check for timeout in nvme_rdma_wait_for_cm()
nvmet: use strcmp() instead of strncmp() for subsystem lookup
nvmet: remove unreachable code
nvme: update node paths after adding new path
The PCI DMA API is deprecated, switch to the generic DMA API instead.
Also make use of the dma_set_mask_and_coherent helper to easily set
the streaming an coherent DMA masks together.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no good reason to create a scatterlist in the ubd driver,
it can just iterate the request directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[rw: Folded in improvements as discussed with hch and jens] Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Mon, 15 Oct 2018 16:19:06 +0000 (10:19 -0600)]
nvme-pci: fix hot removal during error handling
A removal waits for the reset_work to complete. If a surprise removal
occurs around the same time as an error triggered controller reset, and
reset work happened to dispatch a command to the removed controller, the
command won't be recovered since the timeout work doesn't do anything
during error recovery. We wouldn't want to wait for timeout handling
anyway, so this patch fixes this by disabling the controller and killing
admin queues prior to syncing with the reset_work.
Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Wed, 10 Oct 2018 15:08:20 +0000 (08:08 -0700)]
nvmet-fcloop: suppress a compiler warning
Building with W=1 enables the compiler warning -Wimplicit-fallthrough=3. That
option does not recognize the fall-through comment in the fcloop driver. Add
a fall-through comment that is recognized for -Wimplicit-fallthrough=3. This
patch avoids that the compiler reports the following warning when building
with W=1:
drivers/nvme/target/fcloop.c:647:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (op == NVMET_FCOP_READDATA)
^
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Wed, 10 Oct 2018 15:08:19 +0000 (08:08 -0700)]
nvme-core: make implicit seed truncation explicit
The nvme_user_io.slba field is 64 bits wide. That value is copied into the
32-bit bio_integrity_payload.bip_iter.bi_sector field. Make that truncation
explicit to avoid that Coverity complains about implicit truncation. See
also Coverity ID 1056486 on http://scan.coverity.com/projects/linux.
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Mon, 8 Oct 2018 21:28:46 +0000 (14:28 -0700)]
nvme-fc: rework the request initialization code
Instead of setting and then clearing the first_sgl pointer for AEN requests,
leave that pointer zero. This patch does not change how requests are
initialized but avoids that Coverity reports the following complaint for
nvme_fc_init_aen_ops():
CID 1418400 (#1 of 1): Out-of-bounds access (OVERRUN)
4. overrun-buffer-val: Overrunning buffer pointed to by aen_op of 312 bytes by passing it to a function which accesses it at byte offset 312.
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Mon, 8 Oct 2018 21:28:52 +0000 (14:28 -0700)]
nvmet: avoid integer overflow in the discard code
Although I'm not sure whether it is a good idea to support large discard
commands, I think integer overflow for discard ranges larger than 4 GB
should be avoided. This patch avoids that smatch reports the following:
drivers/nvme/target/io-cmd-file.c:249:1 nvmet_file_execute_discard() warn: should '((range.nlb)) << req->ns->blksize_shift' be a 64 bit type?
Bart Van Assche [Mon, 8 Oct 2018 21:28:51 +0000 (14:28 -0700)]
nvmet: use strlcpy() instead of strcpy()
Although the code modified by this patch looks fine to me, this patch avoids
that Coverity reports the following complaint (ID 1364971 and ID 1364973):
"You might overrun the 256-character fixed-size string id->subnqn".
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Mon, 8 Oct 2018 21:28:41 +0000 (14:28 -0700)]
nvme-core: rework a NQN copying operation
Although it is easy to see that the code in nvme_init_subnqn() guarantees that
the subsys->nqn string is '\0'-terminated, apparently Coverity is not smart
enough to see this. Make it easier for Coverity to analyze this code by changing
the strncpy() call into a strlcpy() call. This patch does not change the
behavior of the code but fixes Coveritiy ID 1423720.
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
Bart Van Assche [Mon, 8 Oct 2018 21:28:49 +0000 (14:28 -0700)]
nvmet: use strcmp() instead of strncmp() for subsystem lookup
strncmp() stops comparing when either the end of one of the first two arguments
is reached or when 'n' characters have been compared, whichever comes first.
That means that strncmp(s1, s2, n) is equivalent to strcmp(s1, s2) if n exceeds
the length of s1 or the length of s2. Since that is the case in
nvmet_find_get_subsys(), change strncmp() into strcmp(). This patch avoids that
the following warning is reported by smatch:
drivers/nvme/target/core.c:940:1 nvmet_find_get_subsys() error: strncmp() '"nqn.2014-08.org.nvmexpress.discovery"' too small (37 vs 223)
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
Keith Busch [Fri, 5 Oct 2018 15:49:37 +0000 (09:49 -0600)]
nvme: update node paths after adding new path
The nvme namespace paths were being updated only when the current path
was not set or nonoptimized. If a new path comes online that is a better
path for its NUMA node, the multipath selector may continue using the
previously set path on a potentially further node.
This patch re-runs the path assignment after successfully adding a new
optimized path.
Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
Omar Sandoval [Mon, 15 Oct 2018 15:21:34 +0000 (09:21 -0600)]
floppy: convert to blk-mq
This driver likes to fetch requests from all over the place, so make
queue_rq put requests on a list so that the logic stays the same. Tested
with QEMU.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Converted to blk_mq_init_sq_queue() and fixed a few spots where the
tag_set leaked on cleanup.
Omar Sandoval [Mon, 15 Oct 2018 15:18:24 +0000 (09:18 -0600)]
ataflop: convert to blk-mq
This driver is already pretty broken, in that it has two wait_events()
(one in stdma_lock()) in request_fn. Get rid of the first one by
freezing/quiescing the queue on format, and the second one by replacing
it with stdma_try_lock(). The rest is straightforward. Compile-tested
only and probably incorrect.
Omar Sandoval [Thu, 11 Oct 2018 19:20:49 +0000 (12:20 -0700)]
ataflop: fix error handling during setup
Move queue allocation next to disk allocation to fix a couple of issues:
- If add_disk() hasn't been called, we should clear disk->queue before
calling put_disk().
- If we fail to allocate a request queue, we still need to put all of
the disks, not just the ones that we allocated queues for.
Omar Sandoval [Thu, 11 Oct 2018 19:20:46 +0000 (12:20 -0700)]
amiflop: clean up on errors during setup
The error handling in fd_probe_drives() doesn't clean up at all. Fix it
up in preparation for converting to blk-mq. While we're here, get rid of
the commented out amiga_floppy_remove().
Omar Sandoval [Thu, 11 Oct 2018 19:20:45 +0000 (12:20 -0700)]
amiflop: fold headers into C file
amifd.h and amifdreg.h are only used from amiflop.c, and they're pretty
small, so move the contents to amiflop.c and get rid of the .h files.
This is preparation for adding a struct blk_mq_tag_set to struct
amiga_floppy_struct.
Omar Sandoval [Mon, 15 Oct 2018 15:14:46 +0000 (09:14 -0600)]
swim3: convert to blk-mq
Pretty simple conversion. grab_drive() could probably be replaced by
some freeze/quiesce incantation, but I left it alone, and just used
freeze/quiesce for eject. Compile-tested only.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Omar Sandoval <osandov@fb.com>
Converted to blk_mq_init_sq_queue().
Omar Sandoval [Thu, 11 Oct 2018 19:20:43 +0000 (12:20 -0700)]
swim3: add real error handling in setup
The driver doesn't have support for removing a device that has already
been configured, but with more careful ordering we can avoid the need
for that and make sure that we don't leak generic resources.
Omar Sandoval [Mon, 15 Oct 2018 15:12:12 +0000 (09:12 -0600)]
swim: convert to blk-mq
The only interesting thing here is that there may be two floppies (i.e.,
request queues) sharing the same controller, so we use the global struct
swim_priv->lock to check whether the controller is busy. Compile-tested
only.
Tested-by: Finn Thain <fthain@telegraphics.com.au> Acked-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Omar Sandoval <osandov@fb.com>
Converted to blk_mq_init_sq_queue()
Omar Sandoval [Thu, 11 Oct 2018 19:20:41 +0000 (12:20 -0700)]
swim: fix cleanup on setup error
If we fail to allocate the request queue for a disk, we still need to
free that disk, not just the previous ones. Additionally, we need to
cleanup the previous request queues.
Jens Axboe [Tue, 16 Oct 2018 14:09:58 +0000 (08:09 -0600)]
mtd_blkdevs: convert to blk-mq
Straight forward conversion, using an internal list to enable the
driver to pull requests at will.
Dynamically allocate the tag set to avoid having to pull in the
block headers for blktrans.h, since various mtd drivers use
block conflicting names for defines and functions.
Cc: David Woodhouse <dwmw2@infradead.org> Cc: linux-mtd@lists.infradead.org Tested-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jens Axboe <axboe@kernel.dk>
YueHaibing [Tue, 16 Oct 2018 01:45:26 +0000 (01:45 +0000)]
null_blk: remove set but not used variable 'q'
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/block/null_blk_main.c: In function 'end_cmd':
drivers/block/null_blk_main.c:609:24: warning:
variable 'q' set but not used [-Wunused-but-set-variable]
It not used any more after commit e50b1e327aeb ("null_blk: remove legacy IO path")
Jens Axboe [Sun, 14 Oct 2018 19:20:48 +0000 (13:20 -0600)]
cdrom: don't attempt to fiddle with cdo->capability
We can't modify cdo->capability as it is defined as a const.
Change the modification hack to just WARN_ON_ONCE() if we hit
any of the invalid combinations.
This fixes a regression for pcd, which doesn't work after the
constify patch.
Fixes: 853fe1bf7554 ("cdrom: Make device operations read-only") Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Fri, 12 Oct 2018 16:03:14 +0000 (10:03 -0600)]
aoe: convert aoeblk to blk-mq
Straight forward conversion - instead of rewriting the internal buffer
retrieval logic, just replace the previous elevator peeking with an
internal list of requests.
Reviewed-by: "Ed L. Cashin" <ed.cashin@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jianchao Wang [Fri, 12 Oct 2018 10:07:28 +0000 (18:07 +0800)]
blk-mq: fallback to previous nr_hw_queues when updating fails
When we try to increate the nr_hw_queues, we may fail due to
shortage of memory or other reason, then blk_mq_realloc_hw_ctxs stops
and some entries in q->queue_hw_ctx are left with NULL. However,
because queue map has been updated with new nr_hw_queues, some cpus
have been mapped to hw queue which just encounters allocation failure,
thus blk_mq_map_queue could return NULL. This will cause panic in
following blk_mq_map_swqueue.
To fix it, when increase nr_hw_queues fails, fallback to previous
nr_hw_queues and post warning. At the same time, driver's .map_queues
usually use completion irq affinity to map hw and cpu, fallback
nr_hw_queues will cause lack of some cpu's map to hw, so use default
blk_mq_map_queues to do that.
Reported-by: syzbot+83e8cbe702263932d9d4@syzkaller.appspotmail.com Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jianchao Wang [Fri, 12 Oct 2018 10:07:27 +0000 (18:07 +0800)]
blk-mq: realloc hctx when hw queue is mapped to another node
When the hw queues and mq_map are updated, a hctx could be mapped
to a different numa node. At this moment, we need to realloc the
hctx. If fail to do that, go on using previous hctx.
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jianchao Wang [Fri, 12 Oct 2018 10:07:26 +0000 (18:07 +0800)]
blk-mq: change gfp flags to GFP_NOIO in blk_mq_realloc_hw_ctxs
blk_mq_realloc_hw_ctxs could be invoked during update hw queues.
At the momemt, IO is blocked. Change the gfp flags from GFP_KERNEL
to GFP_NOIO to avoid forever hang during memory allocation in
blk_mq_realloc_hw_ctxs.
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jianchao Wang [Fri, 12 Oct 2018 10:07:25 +0000 (18:07 +0800)]
blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues
blk-mq debugfs and sysfs entries need to be removed before updating
queue map, otherwise, we get get wrong result there. This patch fixes
it and remove the redundant debugfs and sysfs register/unregister
operations during __blk_mq_update_nr_hw_queues.
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
bfq defines as asymmetric a scenario where an active entity, say E
(representing either a single bfq_queue or a group of other entities),
has a higher weight than some other entities. If the entity E does sync
I/O in such a scenario, then bfq plugs the dispatch of the I/O of the
other entities in the following situation: E is in service but
temporarily has no pending I/O request. In fact, without this plugging,
all the times that E stops being temporarily idle, it may find the
internal queues of the storage device already filled with an
out-of-control number of extra requests, from other entities. So E may
have to wait for the service of these extra requests, before finally
having its own requests served. This may easily break service
guarantees, with E getting less than its fair share of the device
throughput. Usually, the end result is that E gets the same fraction of
the throughput as the other entities, instead of getting more, according
to its higher weight.
Yet there are two other more subtle cases where E, even if its weight is
actually equal to or even lower than the weight of any other active
entities, may get less than its fair share of the throughput in case the
above I/O plugging is not performed:
1. other entities issue larger requests than E;
2. other entities contain more active child entities than E (or in
general tend to have more backlog than E).
In the first case, other entities may get more service than E because
they get larger requests, than those of E, served during the temporary
idle periods of E. In the second case, other entities get more service
because, by having many child entities, they have many requests ready
for dispatching while E is temporarily idle.
This commit addresses this issue by extending the definition of
asymmetric scenario: a scenario is asymmetric when
- active entities representing bfq_queues have differentiated weights,
as in the original definition
or (inclusive)
- one or more entities representing groups of entities are active.
This broader definition makes sure that I/O plugging will be performed
in all the above cases, provided that there is at least one active
group. Of course, this definition is very coarse, so it will trigger
I/O plugging also in cases where it is not needed, such as, e.g.,
multiple active entities with just one child each, and all with the same
I/O-request size. The reason for this coarse definition is just that a
finer-grained definition would be rather heavy to compute.
On the opposite end, even this new definition does not trigger I/O
plugging in all cases where there is no active group, and all bfq_queues
have the same weight. So, in these cases some unfairness may occur if
there are asymmetries in I/O-request sizes. We made this choice because
I/O plugging may lower throughput, and probably a user that has not
created any group cares more about throughput than about perfect
fairness. At any rate, as for possible applications that may care about
service guarantees, bfq already guarantees a high responsiveness and a
low latency to soft real-time applications automatically.
cfq: clear queue pointers from cfqg after unpinning them in cfq_pd_offline
BFQ is already doing a similar thing in its .pd_offline_fn() method
implementation.
While it seems that after commit 4c6994806f70
("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()")
was reverted leaving these pointers intact no longer causes crashes
clearing them is still a sensible thing to do to make the code more robust.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block: remove redundant 'default n' from Kconfig-s
'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
block: remove redundant 'default n' from Kconfig-s
'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Javier González [Tue, 9 Oct 2018 11:12:15 +0000 (13:12 +0200)]
lightnvm: pblk: guarantee that backpointer is respected on writer stall
pblk's write buffer must guarantee that it respects the device's
constrains for reads (i.e., mw_cunits). This is done by maintaining a
backpointer that updates the L2P table as entries wrap up, making them
point to the media instead of pointing to the write buffer.
This mechanism can race in case that the write thread stalls, as the
write pointer will protect the last written entry, thus disregarding the
read constrains.
This patch adds an extra check on wrap up, making sure that the
threshold is respected at all times, preventing new entries to overwrite
committed data, also in case of write thread stall.
Zhoujie Wu [Tue, 9 Oct 2018 11:12:14 +0000 (13:12 +0200)]
lightnvm: pblk: consider max hw sectors supported for max_write_pgs
When do GC, the number of read/write sectors are determined
by max_write_pgs(see gc_rq preparation in pblk_gc_line_prepare_ws).
Due to max_write_pgs doesn't consider max hw sectors
supported by nvme controller(128K), which leads to GC
tries to read 64 * 4K in one command, and see below error
caused by pblk_bio_map_addr in function pblk_submit_read_gc.
[ 2923.005376] pblk: could not add page to bio
[ 2923.005377] pblk: could not allocate GC bio (18446744073709551604)
Javier González [Tue, 9 Oct 2018 11:12:12 +0000 (13:12 +0200)]
lightnvm: do no update csecs and sos on 1.2
1.2 devices exposes their data and metadata size through the separate
identify command. Make sure that the NVMe LBA format does not override
these values.
Javier González [Tue, 9 Oct 2018 11:12:11 +0000 (13:12 +0200)]
lightnvm: pblk: guarantee mw_cunits on read buffer
OCSSD 2.0 defines the amount of data that the host must buffer per chunk
to guarantee reads through the geometry field mw_cunits. This value is
the base that pblk uses to determine the size of its read buffer.
Currently, this size is set to be the closes power-of-2 to mw_cunits
times the number of parallel units available to the pblk instance for
each open line (currently one). When an entry (4KB) is put in the
buffer, the L2P table points to it. As the buffer wraps up, the L2P is
updated to point to addresses on the device, thus guaranteeing mw_cunits
at a chunk level.
However, given that pblk cannot write to the device under ws_min
(normally ws_opt), there might be a window in which the buffer starts
wrapping up and updating L2P entries before the mw_cunits value in a
chunk has been surpassed.
In order not to violate the mw_cunits constrain in this case, account
for ws_opt on the read buffer creation.
Javier González [Tue, 9 Oct 2018 11:12:10 +0000 (13:12 +0200)]
lightnvm: pblk: move ring buffer alloc/free rb init
pblk's read/write buffer currently takes a buffer and its size and uses
it to create the metadata around it to use it as a ring buffer. This
puts the responsibility of allocating/freeing ring buffer memory on the
ring buffer user. Instead, move it inside of the ring buffer helpers
(pblk-rb.c). This simplifies creation/destruction routines.
Javier González [Tue, 9 Oct 2018 11:12:09 +0000 (13:12 +0200)]
lightnvm: pblk: encapsulate rb pointer operations
pblk's read/write buffer is always a power-of-2, thus wrapping up the
buffer can be done with a bit mask. Since this is an implementation
detail internal to the write buffer, make a helper that hides pointer
increment + wrap, and allows to transparently relax this assumption in
the future.
Javier González [Tue, 9 Oct 2018 11:12:07 +0000 (13:12 +0200)]
lightnvm: pblk: fix race on sysfs line state
pblk exposes a sysfs interface that represents its internal state. Part
of this state is the map bitmap for the current open line, which should
be protected by the line lock to avoid a race when freeing the line
metadata. Currently, it is not.
This patch makes sure that the line state is consistent and NULL
bitmap pointers are not dereferenced.
Javier González [Tue, 9 Oct 2018 11:12:05 +0000 (13:12 +0200)]
lightnvm: pblk: recover open lines on 2.0 devices
In the OCSSD 2.0 spec, each chunk reports its write pointer. This means
that pblk does not need to scan open lines to find the write pointer,
but instead, it can retrieve it directly (and verify it).
This patch uses the write pointer on open lines to (i) recover the line
up until the last written lba and (ii) reconstruct the map bitmap and
rest of line metadata so that the line can be used for new data.
Since the 1.2 path in lightnvm core has been re-implemented to populate
the chunk structure and thus recover the write pointer on
initialization, this patch removes 1.2 specific recovery, as the 2.0
path can be reused.
Javier González [Tue, 9 Oct 2018 11:12:04 +0000 (13:12 +0200)]
lightnvm: pblk: take write semaphore on metadata
pblk guarantees write ordering at a chunk level through a per open chunk
semaphore. At this point, since we only have an open I/O stream for both
user and GC data, the semaphore is per parallel unit.
For the metadata I/O that is synchronous, the semaphore is not needed as
ordering is guaranteed. However, if the metadata scheme changes or
multiple streams are open, this guarantee might not be preserved.
This patch makes sure that all writes go through the semaphore, even for
synchronous I/O. This is consistent with pblk's write I/O model. It also
simplifies maintenance since changes in the metadata scheme could cause
ordering issues.
Javier González [Tue, 9 Oct 2018 11:12:03 +0000 (13:12 +0200)]
lightnvm: pblk: refactor metadata paths
pblk maintains two different metadata paths for smeta and emeta, which
store metadata at the start of the line and at the end of the line,
respectively. Until now, these path has been common for writing and
retrieving metadata, however, as these paths diverge, the common code
becomes less clear and unnecessary complicated.
In preparation for further changes to the metadata write path, this
patch separates the write and read paths for smeta and emeta and
removes the synchronous emeta path as it not used anymore (emeta is
scheduled asynchronously to prevent jittering due to internal I/Os).
Javier González [Tue, 9 Oct 2018 11:12:02 +0000 (13:12 +0200)]
lightnvm: pblk: encapsulate rqd dma allocations
dma allocations for ppa_list and meta_list in rqd are replicated in
several places across the pblk codebase. Make helpers to encapsulate
creation and deletion to simplify the code.
Javier González [Tue, 9 Oct 2018 11:12:01 +0000 (13:12 +0200)]
lightnvm: use internal allocation for chunk log page
The lightnvm subsystem provides helpers to retrieve chunk metadata,
where the target needs to provide a buffer to store the metadata. An
implicit assumption is that this buffer is contiguous and can be used to
retrieve the data from the device. If the device exposes too many
chunks, then kmalloc might fail, thus failing instance creation.
This patch removes this assumption by implementing an internal buffer in
the lightnvm subsystem to retrieve chunk metadata. Targets can then
use virtual memory allocations. Since this is a target API change, adapt
pblk accordingly.
Signed-off-by: Javier González <javier@cnexlabs.com> Reviewed-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Hans Holmberg [Tue, 9 Oct 2018 11:11:58 +0000 (13:11 +0200)]
lightnvm: pblk: stop recreating global caches
Pblk should not create a set of global caches every time
a pblk instance is created. The global caches should be
made available only when there is one or more pblk instances.
This patch bundles the global caches together with a kref
keeping track of whether the caches should be available or not.
Also, turn the global pblk lock into a mutex that explicitly
protects the caches (as this was the only purpose of the lock).
Hans Holmberg [Tue, 9 Oct 2018 11:11:52 +0000 (13:11 +0200)]
lightnvm: pblk: add trace events for chunk states
Introduce trace points for tracking chunk states in pblk - this is
useful for inspection of the entire state of the drive, and real handy
for both fw and pblk debugging.
Matias Bjørling [Tue, 9 Oct 2018 11:11:51 +0000 (13:11 +0200)]
lightnvm: pblk: remove debug from pblk_[down/up]_page
Remove the debug only iteration within __pblk_down_page, which
then allows us to reduce the number of arguments down to pblk and
the parallel unit from the functions that calls it. Simplifying the
callers logic considerably.
Also, rename the functions pblk_[down/up]_page to
pblk_[down/up]_chunk, to communicate that it manages the write
pointer of the chunk. Note that it also protects the parallel unit
such that at most one chunk is active per parallel unit.
When the user data counter exceeds 32 bits, the write amplification
calculation does not provide the right value. Fix this by using
div64_u64 in stead of div64.
Hans Holmberg [Tue, 9 Oct 2018 11:11:49 +0000 (13:11 +0200)]
lightnvm: pblk: fix up prints in pblk_read_check_rand
The prefix when printing ppas in pblk_read_check_rand should be "rnd"
not "seq", so fix this so we can differentiate between lba missmatches
in random and sequential reads. Also change the print order so
we align with pblk_read_check_seq, printing read lba first.
Hans Holmberg [Tue, 9 Oct 2018 11:11:47 +0000 (13:11 +0200)]
lightnvm: pblk: allocate line map bitmaps using a mempool
Line map bitmap allocations are fairly large and can fail. Allocation
failures are fatal to pblk, stopping the write pipeline. To avoid this,
allocate the bitmaps using a mempool instead.
Mempool allocations never fail if called from a process context,
and pblk *should* only allocate map bitmaps in process context,
but keep the failure handling for robustness sake.
Hans Holmberg [Tue, 9 Oct 2018 11:11:46 +0000 (13:11 +0200)]
lightnvm: introduce nvm_rq_to_ppa_list
There is a number of places in the lightnvm subsystem where the user
iterates over the ppa list. Before iterating, the user must know if it
is a single or multiple LBAs due to vector commands using either the
nvm_rq ->ppa_addr or ->ppa_list fields on command submission, which
leads to open-coding the if/else statement.
Instead of having multiple if/else's, move it into a function that can
be called by its users.
A nice side effect of this cleanup is that this patch fixes up a
bunch of cases where we don't consider the single-ppa case in pblk.
Javier González [Tue, 9 Oct 2018 11:11:45 +0000 (13:11 +0200)]
lightnvm: pblk: guarantee emeta on line close
If a line is recovered from open chunks, the memory structures for
emeta have not necessarily been properly set on line initialization.
When closing a line, make sure that emeta is consistent so that the line
can be recovered on the fast path on next reboot.
Also, remove a couple of empty lines at the end of the function.
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