This commit implements processing of the REQ_OP_ZONE_RESET_ALL operation
for zoned mapped devices. Given that this operation always has a BIO
sector of 0 and a 0 size, processing through the regular BIO
__split_and_process_bio() function does not work because this function
would always select the first target. Instead, handling of this
operation is implemented using the function __send_zone_reset_all().
Similarly to the __send_empty_flush() function, the new
__send_zone_reset_all() function manually goes through all targets of a
mapped device table doing the following:
1) If the target can natively support REQ_OP_ZONE_RESET_ALL,
__send_duplicate_bios() is used to forward the reset all operation to
the target. This case is handled with the
__send_zone_reset_all_native() function.
2) For other targets, the function __send_zone_reset_all_emulated() is
executed to emulate the execution of REQ_OP_ZONE_RESET_ALL using
regular REQ_OP_ZONE_RESET operations.
Targets that can natively support REQ_OP_ZONE_RESET_ALL are identified
using the new target field zone_reset_all_supported. This boolean is set
to true in for targets that have reliable zone limits, that is, targets
that map all sequential write required zones of their zoned device(s).
Setting this field is handled in dm_set_zones_restrictions() and
device_get_zone_resource_limits().
For targets with unreliable zone limits, REQ_OP_ZONE_RESET_ALL must be
emulated (case 2 above). This is implemented with
__send_zone_reset_all_emulated() and is similar to the block layer
function blkdev_zone_reset_all_emulated(): first a report zones is done
for the zones of the target to identify zones that need reset, that is,
any sequential write required zone that is not already empty. This is
done using a bitmap and the function dm_zone_get_reset_bitmap() which
sets to 1 the bit corresponding to a zone that needs reset. Next, this
zone bitmap is inspected and a clone BIO modified to use the
REQ_OP_ZONE_RESET operation issued for any zone with its bit set in the
zone bitmap.
This implementation is more efficient than what the block layer does
with blkdev_zone_reset_all_emulated(), which is always used for DM zoned
devices currently: as we can natively use REQ_OP_ZONE_RESET_ALL on
targets mapping all sequential write required zones, resetting all zones
of a zoned mapped device can be much faster compared to always emulating
this operation using regular per-zone reset. In the worst case, this
implementation is as-efficient as the block layer emulation. This
reduction in the time it takes to reset all zones of a zoned mapped
device depends directly on the mapped device targets mapping (reliable
zone limits or not).
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge MD fixes from Song:
"This PR contains various small fixes by Yu Kuai,
Benjamin Marzinski, Christophe JAILLET, and Yang Li."
* tag 'md-6.11-20240704' of git://git.kernel.org/pub/scm/linux/kernel/git/song/md:
md/raid5: recheck if reshape has finished with device_lock held
md: Don't wait for MD_RECOVERY_NEEDED for HOT_REMOVE_DISK ioctl
md-cluster: Constify struct md_cluster_operations
md: Remove unneeded semicolon
md/raid5: fix spares errors about rcu usage
When handling an IO request, MD checks if a reshape is currently
happening, and if so, where the IO sector is in relation to the reshape
progress. MD uses conf->reshape_progress for both of these tasks. When
the reshape finishes, conf->reshape_progress is set to MaxSector. If
this occurs after MD checks if the reshape is currently happening but
before it calls ahead_of_reshape(), then ahead_of_reshape() will end up
comparing the IO sector against MaxSector. During a backwards reshape,
this will make MD think the IO sector is in the area not yet reshaped,
causing it to use the previous configuration, and map the IO to the
sector where that data was before the reshape.
This bug can be triggered by running the lvm2
lvconvert-raid-reshape-linear_to_raid6-single-type.sh test in a loop,
although it's very hard to reproduce.
Fix this by factoring the code that checks where the IO sector is in
relation to the reshape out to a helper called get_reshape_loc(),
which reads reshape_progress and reshape_safe while holding the
device_lock, and then rechecks if the reshape has finished before
calling ahead_of_reshape with the saved values.
Also use the helper during the REQ_NOWAIT check to see if the location
is inside of the reshape region.
Fixes: fef9c61fdf ("md/raid5: change reshape-progress measurement to cope with reshaping backwards.")
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240702151802.1632010-1-bmarzins@redhat.com
Commit 90f5f7ad4f ("md: Wait for md_check_recovery before attempting
device removal.") explained in the commit message that failed device
must be reomoved from the personality first by md_check_recovery(),
before it can be removed from the array. That's the reason the commit
add the code to wait for MD_RECOVERY_NEEDED.
However, this is not the case now, because remove_and_add_spares() is
called directly from hot_remove_disk() from ioctl path, hence failed
device(marked faulty) can be removed from the personality by ioctl.
On the other hand, the commit introduced a performance problem that
if MD_RECOVERY_NEEDED is set and the array is not running, ioctl will
wait for 5s before it can return failure to user.
Since the waiting is not needed now, fix the problem by removing the
waiting.
Fixes: 90f5f7ad4f ("md: Wait for md_check_recovery before attempting device removal.")
Reported-by: Mateusz Kusiak <mateusz.kusiak@linux.intel.com>
Closes: https://lore.kernel.org/all/814ff6ee-47a2-4ba0-963e-cf256ee4ecfa@linux.intel.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240627112321.3044744-1-yukuai1@huaweicloud.com
'struct md_cluster_operations' is not modified in this driver.
Constifying this structure moves some data to a read-only section, so
increase overall security.
On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
51941 1442 80 53463 d0d7 drivers/md/md-cluster.o
After:
=====
text data bss dec hex filename
52133 1246 80 53459 d0d3 drivers/md/md-cluster.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/3727f3ce9693cae4e62ae6778ea13971df805479.1719173852.git.christophe.jaillet@wanadoo.fr
Ensure that info->sector_size and info->physical_sector_size are set
before the call to blkif_set_queue_limits by doing away with the
local variables and arguments that propagate them.
Thanks to Marek Marczykowski-Górecki and Jürgen Groß for root causing
the issue.
Fixes: ba3f67c116 ("xen-blkfront: atomically update queue limits")
Reported-by: Rusty Bird <rustybird@net-c.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20240625055238.7934-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current tag reservation code is based on a misunderstanding of the
meaning of data->shallow_depth. Fix the tag reservation code as follows:
* By default, do not reserve any tags for synchronous requests because
for certain use cases reserving tags reduces performance. See also
Harshit Mogalapalli, [bug-report] Performance regression with fio
sequential-write on a multipath setup, 2024-03-07
(https://lore.kernel.org/linux-block/5ce2ae5d-61e2-4ede-ad55-551112602401@oracle.com/)
* Reduce min_shallow_depth to one because min_shallow_depth must be less
than or equal any shallow_depth value.
* Scale dd->async_depth from the range [1, nr_requests] to [1,
bits_per_sbitmap_word].
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Zhiguo Niu <zhiguo.niu@unisoc.com>
Fixes: 07757588e5 ("block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240509170149.7639-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
NOWS is one of the annoying "0's based values" in NVMe, where 0 means one
and we thus can't detect if it isn't set. Thus a NOWS value of 0 means
that the Namespace Optimal Write Size is a single LBA, which is clearly
bogus. Ignore the value in that case and don't propagate an io_opt
value to the block layer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240701051800.1245240-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now we avoid throttling swap writes by determining whether the current
process is kswapd (aka current_is_kswapd()), but swap writes can come
from either kswapd or direct reclaim, so the swap writes from direct
reclaim will still be throttled.
When a process holds a lock to allocate a free page, and enters direct
reclaim because there is no free memory, then it might trigger a hung
due to the wbt throttling that causes other processes to fail to get
the lock.
Both kswapd and direct reclaim set the REQ_SWAP flag, so use REQ_SWAP
instead of current_is_kswapd() to avoid throttling swap writes. Also
renamed WBT_KSWAPD to WBT_SWAP and WBT_RWQ_KSWAPD to WBT_RWQ_SWAP.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240604030522.3686177-1-libaokun@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
User will configure allowed iops limit in 1s, and calculate_io_allowed()
will calculate allowed iops in the slice by:
limit * HZ / throtl_slice
However, if limit is quite low, the result can be 0, then
allowed IO in the slice is 0, this will cause missing dispatch and
control will be lower than limit.
For example, set iops_limit to 5 with HD disk, and test will found that
iops will be 3.
This is usually not a big deal, because user will unlikely to configure
such low iops limit, however, this is still a problem in the extreme
scene.
Fix the problem by making sure the wait time calculated by
tg_within_iops_limit() should allow at least one IO to be dispatched.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240618062108.3680835-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
QUEUE_FLAG_NOMERGES isn't really a driver interface, but a user tunable.
There also isn't any good reason to set it in the loop driver.
The original commit adding it (5b5e20f421 "block: loop: set
QUEUE_FLAG_NOMERGES for request queue of loop") claims that "It doesn't
make sense to enable merge because the I/O submitted to backing file is
handled page by page." which of course isn't true for multi-page bvec
now, and it never has been for direct I/O, for which commit 40326d8a33
("block/loop: allow request merge for directio mode") alredy disabled
the nomerges flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240627124926.512662-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
IO logical block size is one fundamental queue limit, and every IO has
to be aligned with logical block size because our bio split can't deal
with unaligned bio.
The check has to be done with queue usage counter grabbed because device
reconfiguration may change logical block size, and we can prevent the
reconfiguration from happening by holding queue usage counter.
logical_block_size stays in the 1st cache line of queue_limits, and this
cache line is always fetched in fast path via bio_may_exceed_limits(),
so IO perf won't be affected by this check.
Cc: Yi Zhang <yi.zhang@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ye Bin <yebin10@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240620030631.3114026-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Sometimes we need to track the processing order of requests with
ioprio set. So the ioprio of request can be useful information.
Example：
block_rq_insert: 8,0 RA 16384 () 6500840 + 32 be,0,6 [binder:815_3]
block_rq_issue: 8,0 RA 16384 () 6500840 + 32 be,0,6 [binder:815_3]
block_rq_complete: 8,0 RA () 6500840 + 32 be,0,6 [0]
Signed-off-by: Dongliang Cui <dongliang.cui@unisoc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240614074936.113659-1-dongliang.cui@unisoc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1. Userspace sends the command "losetup -d" which uses the open() call
to open the device
2. Kernel receives the ioctl command "LOOP_CLR_FD" which calls the
function loop_clr_fd()
3. If LOOP_CLR_FD is the first command received at the time, then the
AUTOCLEAR flag is not set and deletion of the
loop device proceeds ahead and scans the partitions (drop/add
partitions)
if (disk_openers(lo->lo_disk) > 1) {
lo->lo_flags |= LO_FLAGS_AUTOCLEAR;
loop_global_unlock(lo, true);
return 0;
}
4. Before scanning partitions, it will check to see if any partition of
the loop device is currently opened
5. If any partition is opened, then it will return EBUSY:
if (disk->open_partitions)
return -EBUSY;
6. So, after receiving the "LOOP_CLR_FD" command and just before the above
check for open_partitions, if any other command
(like blkid) opens any partition of the loop device, then the partition
scan will not proceed and EBUSY is returned as shown in above code
7. But in "__loop_clr_fd()", this EBUSY error is not propagated
8. We have noticed that this is causing the partitions of the loop to
remain stale even after the loop device is detached resulting in the
IO errors on the partitions
Fix:
Defer the detach of loop device to release function, which is called when
the last close happens, by setting the lo_flags to LO_FLAGS_AUTOCLEAR at
the time of detach i.e in loop_clr_fd() function.
Test case involves the following two scripts:
script1.sh:
while [ 1 ];
do
losetup -P -f /home/opt/looptest/test10.img
blkid /dev/loop0p1
done
script2.sh:
while [ 1 ];
do
losetup -d /dev/loop0
done
Without fix, the following IO errors have been observed:
kernel: __loop_clr_fd: partition scan of loop0 failed (rc=-16)
kernel: I/O error, dev loop0, sector 20971392 op 0x0:(READ) flags 0x80700
phys_seg 1 prio class 0
kernel: I/O error, dev loop0, sector 108868 op 0x0:(READ) flags 0x0
phys_seg 1 prio class 0
kernel: Buffer I/O error on dev loop0p1, logical block 27201, async page
read
Signed-off-by: Gulam Mohamed <gulam.mohamed@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240618164042.343777-1-gulam.mohamed@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
dma_pad_mask is a queue_limits by all ways of looking at it, so move it
there and set it through the atomic queue limits APIs.
Add a little helper that takes the alignment and pad into account to
simplify the code that is touched a bit.
Note that there never was any need for the > check in
blk_queue_update_dma_pad, this probably was just copy and paste from
dma_update_dma_alignment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240626142637.300624-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
