Commit Graph

693518 Commits

Author SHA1 Message Date
Tang Junhui
175206cf9a bcache: initialize dirty stripes in flash_dev_run()
bcache uses a Proportion-Differentiation Controller algorithm to control
writeback rate to cached devices. In the PD controller algorithm, dirty
stripes of thin flash device should not be counted in, because flash only
volumes never write back dirty data.

Currently dirty stripe counter for thin flash device is not initialized
when the thin flash device starts. Which means the following calculation
in PD controller will reference an undefined dirty stripes number, and
all cached devices attached to the same cache set where the thin flash
device lies on may have an inaccurate writeback rate.

This patch calles bch_sectors_dirty_init() in flash_dev_run(), to
correctly initialize dirty stripe counter when the thin flash device
starts to run. This patch also does following parameter data type change,
 -void bch_sectors_dirty_init(struct cached_dev *dc);
 +void bch_sectors_dirty_init(struct bcache_device *);
to call this function conveniently in flash_dev_run().

(Commit log is composed by Coly Li)

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-07 13:32:29 -06:00
Omar Sandoval
bf09375337 loop: set physical block size to logical block size
Commit 6c6b6f28b3 ("loop: set physical block size to PAGE_SIZE")
caused mkfs.xfs to barf on ppc64 [1]. Always using PAGE_SIZE as the
physical block size still makes the most sense semantically, but let's
just lie and always set it to the same value as the logical block size
(same goes for io_min). In the future we might want to at least bump up
io_min to PAGE_SIZE but I'm sick of these stupid changes so let's play
it safe.

1: https://marc.info/?l=linux-xfs&m=150459024723753&w=2

Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 11:08:49 -06:00
Michael Lyle
9276717b9e bcache: fix bch_hprint crash and improve output
Most importantly, solve a crash where %llu was used to format signed
numbers.  This would cause a buffer overflow when reading sysfs
writeback_rate_debug, as only 20 bytes were allocated for this and
%llu writes 20 characters plus a null.

Always use the units mechanism rather than having different output
paths for simplicity.

Also, correct problems with display output where 1.10 was a larger
number than 1.09, by multiplying by 10 and then dividing by 1024 instead
of dividing by 100.  (Remainders of >= 1000 would print as .10).

Minor changes: Always display the decimal point instead of trying to
omit it based on number of digits shown.  Decide what units to use
based on 1000 as a threshold, not 1024 (in other words, always print
at most 3 digits before the decimal point).

Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reported-by: Dmitry Yu Okunev <dyokunev@ut.mephi.ru>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Dan Carpenter
7b6a8570e0 bcache: Update continue_at() documentation
continue_at() doesn't have a return statement anymore.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Dan Carpenter
da22f0eea5 bcache: silence static checker warning
In olden times, closure_return() used to have a hidden return built in.
We removed the hidden return but forgot to add a new return here.  If
"c" were NULL we would oops on the next line, but fortunately "c" is
never NULL.  Let's just remove the if statement.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
9baf30972b bcache: fix for gc and write-back race
gc and write-back get raced (see the email "bcache get stucked" I sended
before):
gc thread                               write-back thread
|                                       |bch_writeback_thread()
|bch_gc_thread()                        |
|                                       |==>read_dirty()
|==>bch_btree_gc()                      |
|==>btree_root() //get btree root       |
|                //node write locker    |
|==>bch_btree_gc_root()                 |
|                                       |==>read_dirty_submit()
|                                       |==>write_dirty()
|                                       |==>continue_at(cl,
|                                       |               write_dirty_finish,
|                                       |               system_wq);
|                                       |==>write_dirty_finish()//excute
|                                       |               //in system_wq
|                                       |==>bch_btree_insert()
|                                       |==>bch_btree_map_leaf_nodes()
|                                       |==>__bch_btree_map_nodes()
|                                       |==>btree_root //try to get btree
|                                       |              //root node read
|                                       |              //lock
|                                       |-----stuck here
|==>bch_btree_set_root()
|==>bch_journal_meta()
|==>bch_journal()
|==>journal_try_write()
|==>journal_write_unlocked() //journal_full(&c->journal)
|                            //condition satisfied
|==>continue_at(cl, journal_write, system_wq); //try to excute
|                               //journal_write in system_wq
|                               //but work queue is excuting
|                               //write_dirty_finish()
|==>closure_sync(); //wait journal_write execute
|                   //over and wake up gc,
|-------------stuck here
|==>release root node write locker

This patch alloc a separate work-queue for write-back thread to avoid such
race.

(Commit log re-organized by Coly Li to pass checkpatch.pl checking)

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Acked-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
89b1fc54c2 bcache: increase the number of open buckets
In currently, we only alloc 6 open buckets for each cache set,
but in usually, we always attach about 10 or so backend devices for
each cache set, and the each bcache device are always accessed by
about 10 or so threads in top application layer. So 6 open buckets
are too few, It has led to that each of the same thread write data
to different buckets, which would cause low efficiency write-back,
and also cause buckets inefficient, and would be Very easy to run
out of.

I add debug message in bch_open_buckets_alloc() to print alloc bucket
info, and test with ten bcache devices with a cache set, and each
bcache device is accessed by ten threads.

From the debug message, we can see that, after the modification, One
bucket is more likely to assign to the same thread, and the data from
the same thread are more likely to write the same bucket. Usually the
same thread always write/read the same backend device, so it is good
for write-back and also promote the usage efficiency of buckets.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tony Asleson
77fa100f27 bcache: Correct return value for sysfs attach errors
If you encounter any errors in bch_cached_dev_attach it will return
a negative error code.  The variable 'v' which stores the result is
unsigned, thus user space sees a very large value returned for bytes
written which can cause incorrect user space behavior.  Utilize 1
signed variable to use throughout the function to preserve error return
capability.

Signed-off-by: Tony Asleson <tasleson@redhat.com>
Acked-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
a8394090a9 bcache: correct cache_dirty_target in __update_writeback_rate()
__update_write_rate() uses a Proportion-Differentiation Controller
algorithm to control writeback rate. A dirty target number is used in
this PD controller to control writeback rate. A larger target number
will make the writeback rate smaller, on the versus, a smaller target
number will make the writeback rate larger.

bcache uses the following steps to calculate the target number,
1) cache_sectors = all-buckets-of-cache-set * buckets-size
2) cache_dirty_target = cache_sectors * cached-device-writeback_percent
3) target = cache_dirty_target *
(sectors-of-cached-device/sectors-of-all-cached-devices-of-this-cache-set)

The calculation at step 1) for cache_sectors is incorrect, which does
not consider dirty blocks occupied by flash only volume.

A flash only volume can be took as a bcache device without cached
device. All data sectors allocated for it are persistent on cache device
and marked dirty, they are not touched by bcache writeback and garbage
collection code. So data blocks of flash only volume should be ignore
when calculating cache_sectors of cache set.

Current code does not subtract dirty sectors of flash only volume, which
results a larger target number from the above 3 steps. And in sequence
the cache device's writeback rate is smaller then a correct value,
writeback speed is slower on all cached devices.

This patch fixes the incorrect slower writeback rate by subtracting
dirty sectors of flash only volumes in __update_writeback_rate().

(Commit log composed by Coly Li to pass checkpatch.pl checking)

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
0b43f49dc4 bcache: gc does not work when triggering by manual command
I try to execute the following command to trigger gc thread:
[root@localhost internal]# echo 1 > trigger_gc
But it does not work, I debug the code in gc_should_run(), It works only
if in invalidating or sectors_to_gc < 0. So set sectors_to_gc to -1 to
meet the condition when we trigger gc by manual command.

(Code comments aded by Coly Li)

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Byungchul Park
09b3efec81 bcache: Don't reinvent the wheel but use existing llist API
Although llist provides proper APIs, they are not used. Make them used.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
69daf03ade bcache: do not subtract sectors_to_gc for bypassed IO
Since bypassed IOs use no bucket, so do not subtract sectors_to_gc to
trigger gc thread.

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Tang Junhui
c81ffa32a2 bcache: fix sequential large write IO bypass
Sequential write IOs were tested with bs=1M by FIO in writeback cache
mode, these IOs were expected to be bypassed, but actually they did not.
We debug the code, and find in check_should_bypass():
    if (!congested &&
        mode == CACHE_MODE_WRITEBACK &&
        op_is_write(bio_op(bio)) &&
        (bio->bi_opf & REQ_SYNC))
        goto rescale
that means, If in writeback mode, a write IO with REQ_SYNC flag will not
be bypassed though it is a sequential large IO, It's not a correct thing
to do actually, so this patch remove these codes.

Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Jan Kara
4b758df21e bcache: Fix leak of bdev reference
If blkdev_get_by_path() in register_bcache() fails, we try to lookup the
block device using lookup_bdev() to detect which situation we are in to
properly report error. However we never drop the reference returned to
us from lookup_bdev(). Fix that.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06 08:17:33 -06:00
Shaohua Li
bc75705d00 block/loop: remove unused field
nobody uses the list.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:57:35 -06:00
Shaohua Li
92d773324b block/loop: fix use after free
lo_rw_aio->call_read_iter->
1       aops->direct_IO
2       iov_iter_revert
lo_rw_aio_complete could happen between 1 and 2, the bio and bvec could
be freed before 2, which accesses bvec.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:57:33 -06:00
Bart Van Assche
12cd3a2fe3 bfq: Use icq_to_bic() consistently
Some code uses icq_to_bic() to convert an io_cq pointer to a
bfq_io_cq pointer while other code uses a direct cast. Convert
the code that uses a direct cast such that it uses icq_to_bic().

Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:56:42 -06:00
Bart Van Assche
1530486cda bfq: Suppress compiler warnings about comparisons
This patch avoids that the following warnings are reported when
building with W=1:

block/bfq-iosched.c: In function 'bfq_back_seek_max_store':
block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4876:1: note: in expansion of macro 'STORE_FUNCTION'
 STORE_FUNCTION(bfq_back_seek_max_store, &bfqd->bfq_back_max, 0, INT_MAX, 0);
 ^~~~~~~~~~~~~~
block/bfq-iosched.c: In function 'bfq_slice_idle_store':
block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4879:1: note: in expansion of macro 'STORE_FUNCTION'
 STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
 ^~~~~~~~~~~~~~
block/bfq-iosched.c: In function 'bfq_slice_idle_us_store':
block/bfq-iosched.c:4892:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4899:1: note: in expansion of macro 'USEC_STORE_FUNCTION'
 USEC_STORE_FUNCTION(bfq_slice_idle_us_store, &bfqd->bfq_slice_idle, 0,
 ^~~~~~~~~~~~~~~~~~~

Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:56:40 -06:00
Bart Van Assche
2f79136ba2 bfq: Check kstrtoul() return value
Make sysfs writes fail for invalid numbers instead of storing
uninitialized data copied from the stack. This patch removes
all uninitialized_var() occurrences from the BFQ source code.

Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:56:39 -06:00
Bart Van Assche
dfb79af546 bfq: Declare local functions static
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:56:37 -06:00
Bart Van Assche
fa393d1b9c bfq: Annotate fall-through in a switch statement
This patch avoids that gcc 7 issues a warning about fall-through
when building with W=1.

Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 13:56:36 -06:00
Jens Axboe
a254d989f3 Merge branch 'nvme-4.14' of git://git.infradead.org/nvme into for-4.14/block-postmerge
Pull NVMe updates from Christoph:

"A few more nvme updates for 4.14:

 - generate a correct default NQN (Daniel Verkamp)
 - metadata passthrough for the NVME_IOCTL_IO_CMD ioctl, as well as
   related fixes and cleanups (Keith)
 - better scalability for connecting to the NVMeOF target (Roland Dreier)
 - target support for reading the host identifier (Omri Mann)"
2017-09-01 13:52:37 -06:00
Shaohua Li
40326d8a33 block/loop: allow request merge for directio mode
Currently loop disables merge. While it makes sense for buffer IO mode,
directio mode can benefit from request merge. Without merge, loop could
send small size IO to underlayer disk and harm performance.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 08:44:34 -06:00
Shaohua Li
54bb0ade66 block/loop: set hw_sectors
Loop can handle any size of request. Limiting it to 255 sectors just
burns the CPU for bio split and request merge for underlayer disk and
also cause bad fs block allocation in directio mode.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01 08:44:32 -06:00
Daniel Verkamp
40a5fce495 nvme-fabrics: generate spec-compliant UUID NQNs
The default host NQN, which is generated based on the host's UUID,
does not follow the UUID-based NQN format laid out in the NVMe 1.3
specification.  Remove the "NVMf:" portion of the NQN to match the spec.

Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-09-01 09:48:01 +02:00
Paolo Valente
2670cd1674 doc, block, bfq: better describe how to properly configure bfq
Many users have reported the lack of an HOWTO for properly configuring
bfq as a function of the goal one wants to achieve (max
responsiveness, max throughput, ...). In fact, all needed details are
already provided in the documentation file bfq-iosched.txt. Yet the
document lacks guidance on which parameter descriptions to look
at. This commit adds some simple direction.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Reviewed-by: Jeremy Hickman <jeremywh7@gmail.com>
Reviewed-by: Laurentiu Nicola <lnicola@dend.ro>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:55:26 -06:00
Paolo Valente
233f0bf415 doc, block, bfq: fix some typos and remove stale stuff
In addition to containing some typos and stale sentences, the file
bfq-iosched.txt still mentioned a set of sysfs parameters that have
been removed from this version of bfq. This commit fixes all these
issues.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Reviewed-by: Jeremy Hickman <jeremywh7@gmail.com>
Reviewed-by: Laurentiu Nicola <lnicola@dend.ro>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:55:25 -06:00
Omar Sandoval
43cade803e loop: fold loop_switch() into callers
The comments here are really outdated, and blk-mq made flushing much
simpler, so just fold the two cases into the callers.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:51:16 -06:00
Omar Sandoval
89e4fdecb5 loop: add ioctl for changing logical block size
This is a different approach from the first attempt in f2c6df7dbf
("loop: support 4k physical blocksize"). Rather than extending
LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block
size.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:51:14 -06:00
Omar Sandoval
6c6b6f28b3 loop: set physical block size to PAGE_SIZE
The physical block size is "the lowest possible sector size that the
hardware can operate on without reverting to read-modify-write
operations" (from the comment on blk_queue_physical_block_size()). Since
loop does buffered I/O on the backing file by default, the RMW unit is a
page. This isn't the case for direct I/O mode, but let's keep it simple.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:51:12 -06:00
Omar Sandoval
8a0740c410 loop: get rid of lo_blocksize
This is only used for setting the soft block size on the struct
block_device once and then never used again.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 13:51:10 -06:00
Paolo Valente
24d90bb2f3 block, bfq: guarantee update_next_in_service always returns an eligible entity
If the function bfq_update_next_in_service is invoked as a consequence
of the activation or requeueing of an entity, say E, then it doesn't
invoke bfq_lookup_next_entity to get the next-in-service entity. In
contrast, it follows a shorter path: if E happens to be eligible (see
commit "bfq-sq-mq: make lookup_next_entity push up vtime on
expirations" for details on eligibility) and to have a lower virtual
finish time than the current candidate as next-in-service entity, then
E directly becomes the next-in-service entity. Unfortunately, there is
a corner case for which this shorter path makes
bfq_update_next_in_service choose a non eligible entity: it occurs if
both E and the current next-in-service entity happen to be non
eligible when bfq_update_next_in_service is invoked. In this case, E
is not set as next-in-service, and, since bfq_lookup_next_entity is
not invoked, the state of the parent entity is not updated so as to
end up with an eligible entity as the proper next-in-service entity.

In this respect, next-in-service is actually allowed to be non
eligible while some queue is in service: since no system-virtual-time
push-up can be performed in that case (see again commit "bfq-sq-mq:
make lookup_next_entity push up vtime on expirations" for details),
next-in-service is chosen, speculatively, as a function of the
possible value that the system virtual time may get after a push
up. But the correctness of the schedule breaks if next-in-service is
still a non eligible entity when it is time to set in service the next
entity. Unfortunately, this may happen in the above corner case.

This commit fixes this problem by making bfq_update_next_in_service
invoke bfq_lookup_next_entity not only if the above shorter path
cannot be taken, but also if the shorter path is taken but fails to
yield an eligible next-in-service entity.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Lee Tibbert <lee.tibbert@gmail.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 08:20:31 -06:00
Paolo Valente
a02195ce86 block, bfq: remove direct switch to an entity in higher class
If the function bfq_update_next_in_service is invoked as a consequence
of the activation or requeueing of an entity, say E, and finds out
that E belongs to a higher-priority class than that of the current
next-in-service entity, then it sets next_in_service directly to
E. But this may lead to anomalous schedules, because E may happen not
be eligible for service, because its virtual start time is higher than
the system virtual time for its service tree.

This commit addresses this issue by simply removing this direct
switch.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Lee Tibbert <lee.tibbert@gmail.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 08:20:29 -06:00
Paolo Valente
80294c3bbf block, bfq: make lookup_next_entity push up vtime on expirations
To provide a very smooth service, bfq starts to serve a bfq_queue
only if the queue is 'eligible', i.e., if the same queue would
have started to be served in the ideal, perfectly fair system that
bfq simulates internally. This is obtained by associating each
queue with a virtual start time, and by computing a special system
virtual time quantity: a queue is eligible only if the system
virtual time has reached the virtual start time of the
queue. Finally, bfq guarantees that, when a new queue must be set
in service, there is always at least one eligible entity for each
active parent entity in the scheduler. To provide this guarantee,
the function __bfq_lookup_next_entity pushes up, for each parent
entity on which it is invoked, the system virtual time to the
minimum among the virtual start times of the entities in the
active tree for the parent entity (more precisely, the push up
occurs if the system virtual time happens to be lower than all
such virtual start times).

There is however a circumstance in which __bfq_lookup_next_entity
cannot push up the system virtual time for a parent entity, even
if the system virtual time is lower than the virtual start times
of all the child entities in the active tree. It happens if one of
the child entities is in service. In fact, in such a case, there
is already an eligible entity, the in-service one, even if it may
not be not present in the active tree (because in-service entities
may be removed from the active tree).

Unfortunately, in the last re-design of the
hierarchical-scheduling engine, the reset of the pointer to the
in-service entity for a given parent entity--reset to be done as a
consequence of the expiration of the in-service entity--always
happens after the function __bfq_lookup_next_entity has been
invoked. This causes the function to think that there is still an
entity in service for the parent entity, and then that the system
virtual time cannot be pushed up, even if actually such a
no-more-in-service entity has already been properly reinserted
into the active tree (or in some other tree if no more
active). Yet, the system virtual time *had* to be pushed up, to be
ready to correctly choose the next queue to serve. Because of the
lack of this push up, bfq may wrongly set in service a queue that
had been speculatively pre-computed as the possible
next-in-service queue, but that would no more be the one to serve
after the expiration and the reinsertion into the active trees of
the previously in-service entities.

This commit addresses this issue by making
__bfq_lookup_next_entity properly push up the system virtual time
if an expiration is occurring.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Lee Tibbert <lee.tibbert@gmail.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31 08:20:28 -06:00
Omri Mann
28dd5cf70a nvmet: add support for reporting the host identifier
And fix the Get/Set Log Page implementation to take all 8 bits of the
feature identifier into account.

Signed-off-by: Omri Mann <omri@excelero.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[hch: used the UUID API, updated changelog]
2017-08-30 15:05:18 +02:00
Keith Busch
63263d60e0 nvme: Use metadata for passthrough commands
The ioctls' struct allows the user to provide a metadata address and
length for a passthrough command. This patch uses these values that were
previously ignored and deletes the now unused wrapper function.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-30 14:59:35 +02:00
Keith Busch
485783ca63 nvme: Make nvme user functions static
These functions are used only locally in the nvme core.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-30 14:59:34 +02:00
Keith Busch
b5d8af5b52 nvme/pci: Use req_op to determine DIF remapping
Only read and write commands need DIF remapping. Everything else uses
a passthrough integrity payload.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-30 14:59:33 +02:00
Christoph Hellwig
1cad65620f nvme: factor metadata handling out of __nvme_submit_user_cmd
Keep the metadata code in a separate helper instead of making the
main function more complicated.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-30 14:59:30 +02:00
Roland Dreier
489beb91e6 nvme-fabrics: Convert nvmf_transports_mutex to an rwsem
The mutex protects against the list of transports changing while a
controller is being created, but using a plain old mutex means that it
also serializes controller creation.  This unnecessarily slows down
creating multiple controllers - for example for the RDMA transport,
creating a controller involves establishing one connection for every IO
queue, which involves even more network/software round trips, so the
delay can become significant.

The simplest way to fix this is to change the mutex to an rwsem and only
hold it for writing when the list is being mutated.  Since we can take
the rwsem for reading while creating a controller, we can create multiple
controllers in parallel.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-30 14:51:22 +02:00
Jens Axboe
2b76da9563 Merge branch 'nvme-4.14' of git://git.infradead.org/nvme into for-4.14/block-postmerge
Pull NVMe changes from Christoph:

"Below is the current set of NVMe updates for Linux 4.14, now against
 your postmerge branch, and with three more patches.

 The biggest bit comes from Sagi and refactors the RDMA driver to
 prepare for more code sharing in the setup and teardown path.  But we
 have various features and bug fixes from a lot of people as well."
2017-08-29 09:09:11 -06:00
Christoph Hellwig
1d5df6af8c nvme: don't blindly overwrite identifiers on disk revalidate
Instead validate that these identifiers do not change, as that is
prohibited by the specification.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2017-08-29 10:23:04 +02:00
Christoph Hellwig
cdbff4f26b nvme: remove nvme_revalidate_ns
The function is used in two places, and the shared code for those will
diverge later in this series.

Instead factor out a new helper to get the ids for a namespace, simplify
the calling conventions for nvme_identify_ns and just open code the
sequence.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
2017-08-29 10:22:39 +02:00
Christoph Hellwig
57eeaf8ec6 nvme: remove unused struct nvme_ns fields
And move the flags for the flags field near that field while touching
this area.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
2017-08-29 10:22:26 +02:00
Christoph Hellwig
0a72bbba49 nvme: allow calling nvme_change_ctrl_state from irq context
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
2017-08-29 10:22:23 +02:00
Christoph Hellwig
a751da3394 nvme: report more detailed status codes to the block layer
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
2017-08-29 10:22:18 +02:00
Martin K. Petersen
07fbd32a6b nvme: honor RTD3 Entry Latency for shutdowns
If an NVMe controller reports RTD3 Entry Latency larger than
shutdown_timeout, up to a maximum of 60 seconds, use that value to set
the shutdown timer. Otherwise fall back to the module parameter which
defaults to 5 seconds.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
[hch: removed do_div, made transition time local scope]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-28 23:00:44 +03:00
Jan H. Schönherr
5228b3280b nvme: fix uninitialized prp2 value on small transfers
The value of iod->first_dma ends up as prp2 in NVMe commands. In case
there is not enough data to cross a page boundary, iod->first_dma is
never initialized and contains random data.

Comply with the NVMe specification and fill in 0 in that case.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-28 23:00:44 +03:00
Max Gurtovoy
a7b7c7a105 nvme-rdma: Use unlikely macro in the fast path
This patch slightly improves performance (mainly for small block sizes).

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-28 23:00:43 +03:00
Martin Wilck
17c39d053a nvmet: use memcpy_and_pad for identify sn/fr
This changes the earlier patch "nvmet: don't report 0-bytes
in serial number" to use the memcpy_and_pad() helper introduced
in a previous patch.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimbeg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-28 23:00:42 +03:00