In order to improve consistency and usability in cgroup stat accounting,
we would like to support the root cgroup's io.stat.
Since the root cgroup has processes doing io even if the system has no
explicitly created cgroups, we need to be careful to avoid overhead in
that case. For that reason, the rstat algorithms don't handle the root
cgroup, so just turning the file on wouldn't give correct statistics.
To get around this, we simulate flushing the iostat struct by filling it
out directly from global disk stats. The result is a root cgroup io.stat
file consistent with both /proc/diskstats and io.stat.
Note that in order to collect the disk stats, we needed to iterate over
devices. To facilitate that, we had to change the linkage of a disk_type
to external so that it can be used from blk-cgroup.c to iterate over
disks.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Boris Burkov <boris@bur.io>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Large part of bio.h, blkdev.h and genhd.h are under ifdef CONFIG_BLOCK
for no good reason. Only stub out function that are called from
code that is not dependent on CONFIG_BLOCK and leave the harmless
other declarations around.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move most of the block related definition out of fs.h into more suitable
headers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block driver updates from Jens Axboe:
"On top of the core changes, here are the block driver changes for this
merge window:
- NVMe changes:
- NVMe over Fibre Channel protocol updates, which also reach
over to drivers/scsi/lpfc (James Smart)
- namespace revalidation support on the target (Anthony
Iliopoulos)
- gcc zero length array fix (Arnd Bergmann)
- nvmet cleanups (Chaitanya Kulkarni)
- misc cleanups and fixes (me, Keith Busch, Sagi Grimberg)
- use a SRQ per completion vector (Max Gurtovoy)
- fix handling of runtime changes to the queue count (Weiping
Zhang)
- t10 protection information support for nvme-rdma and
nvmet-rdma (Israel Rukshin and Max Gurtovoy)
- target side AEN improvements (Chaitanya Kulkarni)
- various fixes and minor improvements all over, icluding the
nvme part of the lpfc driver"
- Floppy code cleanup series (Willy, Denis)
- Floppy contention fix (Jiri)
- Loop CONFIGURE support (Martijn)
- bcache fixes/improvements (Coly, Joe, Colin)
- q->queuedata cleanups (Christoph)
- Get rid of ioctl_by_bdev (Christoph, Stefan)
- md/raid5 allocation fixes (Coly)
- zero length array fixes (Gustavo)
- swim3 task state fix (Xu)"
* tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits)
bcache: configure the asynchronous registertion to be experimental
bcache: asynchronous devices registration
bcache: fix refcount underflow in bcache_device_free()
bcache: Convert pr_<level> uses to a more typical style
bcache: remove redundant variables i and n
lpfc: Fix return value in __lpfc_nvme_ls_abort
lpfc: fix axchg pointer reference after free and double frees
lpfc: Fix pointer checks and comments in LS receive refactoring
nvme: set dma alignment to qword
nvmet: cleanups the loop in nvmet_async_events_process
nvmet: fix memory leak when removing namespaces and controllers concurrently
nvmet-rdma: add metadata/T10-PI support
nvmet: add metadata support for block devices
nvmet: add metadata/T10-PI support
nvme: add Metadata Capabilities enumerations
nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len
nvmet: rename nvmet_rw_len to nvmet_rw_data_len
nvmet: add metadata characteristics for a namespace
nvme-rdma: add metadata/T10-PI support
nvme-rdma: introduce nvme_rdma_sgl structure
...
percpu variables have a perfectly fine working stub implementation
for UP kernels, so use that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This will reduce the amount of ifdefs inside the source code for various
drivers and also will reduce the amount of stub functions that were
created for the !CONFIG_BLK_DEV_INTEGRITY case.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add a pointer to the CDROM information structure to struct gendisk.
This will allow various removable media file systems to call directly
into the CDROM layer instead of abusing ioctls with kernel pointers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The gendisk can be trivially deducted from the block_device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block updates from Jens Axboe:
- Online capacity resizing (Balbir)
- Number of hardware queue change fixes (Bart)
- null_blk fault injection addition (Bart)
- Cleanup of queue allocation, unifying the node/no-node API
(Christoph)
- Cleanup of genhd, moving code to where it makes sense (Christoph)
- Cleanup of the partition handling code (Christoph)
- disk stat fixes/improvements (Konstantin)
- BFQ improvements (Paolo)
- Various fixes and improvements
* tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
block: return NULL in blk_alloc_queue() on error
block: move bio_map_* to blk-map.c
Revert "blkdev: check for valid request queue before issuing flush"
block: simplify queue allocation
bcache: pass the make_request methods to blk_queue_make_request
null_blk: use blk_mq_init_queue_data
block: add a blk_mq_init_queue_data helper
block: move the ->devnode callback to struct block_device_operations
block: move the part_stat* helpers from genhd.h to a new header
block: move block layer internals out of include/linux/genhd.h
block: move guard_bio_eod to bio.c
block: unexport get_gendisk
block: unexport disk_map_sector_rcu
block: unexport disk_get_part
block: mark part_in_flight and part_in_flight_rw static
block: mark block_depr static
block: factor out requeue handling from dispatch code
block/diskstats: replace time_in_queue with sum of request times
block/diskstats: accumulate all per-cpu counters in one pass
block/diskstats: more accurate approximation of io_ticks for slow disks
...
There really isn't any good reason to stash a method directly into
struct gendisk. Move it together with the other block device
operations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
These macros are just used by a few files. Move them out of genhd.h,
which is included everywhere into a new standalone header.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Column "time_in_queue" in diskstats is supposed to show total waiting time
of all requests. I.e. value should be equal to the sum of times from other
columns. But this is not true, because column "time_in_queue" is counted
separately in jiffies rather than in nanoseconds as other times.
This patch removes redundant counter for "time_in_queue" and shows total
time of read, write, discard and flush requests.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently io_ticks is approximated by adding one at each start and end of
requests if jiffies counter has changed. This works perfectly for requests
shorter than a jiffy or if one of requests starts/ends at each jiffy.
If disk executes just one request at a time and they are longer than two
jiffies then only first and last jiffies will be accounted.
Fix is simple: at the end of request add up into io_ticks jiffies passed
since last update rather than just one jiffy.
Example: common HDD executes random read 4k requests around 12ms.
fio --name=test --filename=/dev/sdb --rw=randread --direct=1 --runtime=30 &
iostat -x 10 sdb
Note changes of iostat's "%util" 8,43% -> 99,99% before/after patch:
Before:
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdb 0,00 0,00 82,60 0,00 330,40 0,00 8,00 0,96 12,09 12,09 0,00 1,02 8,43
After:
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdb 0,00 0,00 82,50 0,00 330,00 0,00 8,00 1,00 12,10 12,10 0,00 12,12 99,99
Now io_ticks does not loose time between start and end of requests, but
for queue-depth > 1 some I/O time between adjacent starts might be lost.
For load estimation "%util" is not as useful as average queue length,
but it clearly shows how often disk queue is completely empty.
Fixes: 5b18b5a737 ("block: delete part_round_stats and switch to less precise counting")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
All these are just used in block/partitions/msdos.c, so move them out of the
genhd.h driver included by every driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The enum containing the *_PARTITION symbolic names is only relevant
for the partition parser. More specifically most values are MSDOS
partition table system indicators and thus should go straight into
msdos.c. One value is only used by the sun partition parser, and the
sun and sgi partition parsers use the same value as the x86 Linux
RAID indicator to also indicate RAID autodetection. Duplicate them
in sun.c and sgi.c given that the different partition types use
entirely different values otherwise.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
struct partition is the on-disk format of a MSDOS partition table entry.
Move it out of genhd.h into a new msdos_partition.h header and give it
a msdos_ prefix to avoid confusion.
Also move the magic number from block/partitions/msdos.h to the new
header so that it can be used by the SCSI drivers looking at the DOS
partition tables.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There isn't any good reason not to simply open code the allocation and
freeing of the partition_meta_info structure. Especially as one of
the branches in alloc_part_info is entirely dead code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the sysfs _show methods that are used both on the full disk and
partition nodes to genhd.c instead of hiding them in the partitioning
code. Also move the declaration for these methods to block/blk.h so
that we don't expose them to drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allow block/genhd to notify user space (via udev) about disk size changes
using a new helper set_capacity_revalidate_and_notify(), which is a wrapper
on top of set_capacity(). set_capacity_revalidate_and_notify() will only
notify via udev if the current capacity or the target capacity is not zero
and iff the capacity changes.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com>
Signed-off-by: Balbir Singh <sblbir@amazon.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
