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The ns variable has been removed in commit 62451a2b2e7e ("nvme: separate
command prep and issue"). Drop reference to ns in comment.
Fixes: 62451a2b2e7e ("nvme: separate command prep and issue")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Refactor nvme_fc_create_io_queues() and nvme_fc_recreate_io_queues() to
use the min3() macro to find the minimum between 3 values instead of
multiple min()'s. This shortens the code and makes it easier to read.
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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This patch helps add nvme native multipath visibility for queue-depth
io-policy. It adds a new attribute file named "queue_depth" under
namespace device path node which would print the number of active/
in-flight I/O requests currently queued for the given path.
For instance, if we have a shared namespace accessible from two different
controllers/paths then accessing head block node of the shared namespace
would show the following output:
$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1
In the above example, nvme1n1 is head gendisk node created for a shared
namespace and the namespace is accessible from nvme1c1n1 and nvme1c3n1
paths. For queue-depth io-policy we can then refer the "queue_depth"
attribute file created under each namespace path:
$ cat /sys/block/nvme1n1/multipath/nvme1c1n1/queue_depth
518
$cat /sys/block/nvme1n1/multipath/nvme1c3n1/queue_depth
504
>From the above output, we can infer that I/O workload targeted at nvme1n1
uses two paths nvme1c1n1 and nvme1c3n1 and the current queue depth of each
path is 518 and 504 respectively. Reading "queue_depth" file when
configured io-policy is anything but queue-depth would show no output.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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This patch helps add nvme native multipath visibility for numa io-policy.
It adds a new attribute file named "numa_nodes" under namespace gendisk
device path node which prints the list of numa nodes preferred by the
given namespace path. The numa nodes value is comma delimited list of
nodes or A-B range of nodes.
For instance, if we have a shared namespace accessible from two different
controllers/paths then accessing head node of the shared namespace would
show the following output:
$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1
In the above example, nvme1n1 is head gendisk node created for a shared
namespace and this namespace is accessible from nvme1c1n1 and nvme1c3n1
paths. For numa io-policy we can then refer the "numa_nodes" attribute
file created under each namespace path:
$ cat /sys/block/nvme1n1/multipath/nvme1c1n1/numa_nodes
0-1
$ cat /sys/block/nvme1n1/multipath/nvme1c3n1/numa_nodes
2-3
>From the above output, we infer that I/O workload targeted at nvme1n1
and running on numa nodes 0 and 1 would prefer using path nvme1c1n1.
Similarly, I/O workload running on numa nodes 2 and 3 would prefer
using path nvme1c3n1. Reading "numa_nodes" file when configured
io-policy is anything but numa would show no output.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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This patch helps add nvme native multipath visibility for round-robin
io-policy. It creates a "multipath" sysfs directory under head gendisk
device node directory and then from "multipath" directory it adds a link
to each namespace path device the head node refers.
For instance, if we have a shared namespace accessible from two different
controllers/paths then we create a soft link to each path device from head
disk node as shown below:
$ ls -l /sys/block/nvme1n1/multipath/
nvme1c1n1 -> ../../../../../pci052e:78/052e:78:00.0/nvme/nvme1/nvme1c1n1
nvme1c3n1 -> ../../../../../pci058e:78/058e:78:00.0/nvme/nvme3/nvme1c3n1
In the above example, nvme1n1 is head gendisk node created for a shared
namespace and the namespace is accessible from nvme1c1n1 and nvme1c3n1
paths.
For round-robin I/O policy, we could easily infer from the above output
that I/O workload targeted to nvme1n1 would toggle across paths nvme1c1n1
and nvme1c3n1.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add debugfs entries to display the 'concat' and 'tls_key' controller
attributes.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Evaluate the SC_C flag during DH-CHAP-HMAC negotiation to check if secure
concatenation as specified in the NVMe Base Specification v2.1, section
8.3.4.3: "Secure Channel Concatenationand" is requested. If requested the
generated PSK is inserted into the keyring once negotiation has finished
allowing for an encrypted connection once the admin queue is restarted.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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For secure concatenation the result of the TLS handshake will be
stored in the 'sq' struct, so add it to the alloc_ctrl_args struct.
Cc: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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When secure concatenation is requested the connection needs to be
reset to enable TLS encryption on the new cnnection.
That implies that the original connection used for the DH-CHAP
negotiation really shouldn't be used, and we should reset as soon
as the DH-CHAP negotiation has succeeded on the admin queue.
Based on an idea from Sagi.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add a fabrics option 'concat' to request secure channel concatenation as
specified the NVME Base Specification v2.1, section 8.3.4.3: Secure Channel
Concatenation.
When secure channel concatenation is enabled a 'generated PSK' is inserted
into the keyring such that it's available after reset.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add a function to refresh a generated PSK in the specified keyring.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add a function to derive the TLS PSK as specified TP8018.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add a function to calculate the PSK digest as specified in TP8018.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Add a function to generate a NVMe PSK from the shared credentials
negotiated by DH-HMAC-CHAP.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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Separate out the HKDF functions into a separate module to
to make them available to other callers.
And add a testsuite to the module with test vectors
from RFC 5869 (and additional vectors for SHA384 and SHA512)
to ensure the integrity of the algorithm.
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Acked-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Keith Busch <kbusch@kernel.org>
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The /sys/block/<disk>/integrity fields are historically set
if T10 protection Information is enabled.
It is not set if some upper layer uses integrity metadata.
Document it.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Co-developed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250318154447.370786-1-gmazyland@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In case blkg_conf_open_bdev_frozen() fails, ioc_qos_write() jumps to the
error path without assigning a value to 'ret'. Ensure that it inherits
the error from the passed back error value.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503200454.QWpwKeJu-lkp@intel.com/
Fixes: 9730763f4756 ("block: correct locking order for protecting blk-wbt parameters")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The commit '245618f8e45f ("block: protect wbt_lat_usec using q->
elevator_lock")' introduced q->elevator_lock to protect updates
to blk-wbt parameters when writing to the sysfs attribute wbt_
lat_usec and the cgroup attribute io.cost.qos. However, both
these attributes also acquire q->rq_qos_mutex, leading to the
following lockdep warning:
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc5+ #138 Not tainted
------------------------------------------------------
bash/5902 is trying to acquire lock:
c000000085d495a0 (&q->rq_qos_mutex){+.+.}-{4:4}, at: wbt_init+0x164/0x238
but task is already holding lock:
c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&q->elevator_lock){+.+.}-{4:4}:
__mutex_lock+0xf0/0xa58
ioc_qos_write+0x16c/0x85c
cgroup_file_write+0xc4/0x32c
kernfs_fop_write_iter+0x1b8/0x29c
vfs_write+0x410/0x584
ksys_write+0x84/0x140
system_call_exception+0x134/0x360
system_call_vectored_common+0x15c/0x2ec
-> #0 (&q->rq_qos_mutex){+.+.}-{4:4}:
__lock_acquire+0x1b6c/0x2ae0
lock_acquire+0x140/0x430
__mutex_lock+0xf0/0xa58
wbt_init+0x164/0x238
queue_wb_lat_store+0x1dc/0x20c
queue_attr_store+0x12c/0x164
sysfs_kf_write+0x6c/0xb0
kernfs_fop_write_iter+0x1b8/0x29c
vfs_write+0x410/0x584
ksys_write+0x84/0x140
system_call_exception+0x134/0x360
system_call_vectored_common+0x15c/0x2ec
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->elevator_lock);
lock(&q->rq_qos_mutex);
lock(&q->elevator_lock);
lock(&q->rq_qos_mutex);
*** DEADLOCK ***
6 locks held by bash/5902:
#0: c000000051122400 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x84/0x140
#1: c00000007383f088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x174/0x29c
#2: c000000008550428 (kn->active#182){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x180/0x29c
#3: c000000085d493a8 (&q->q_usage_counter(io)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40
#4: c000000085d493e0 (&q->q_usage_counter(queue)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40
#5: c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c
stack backtrace:
CPU: 17 UID: 0 PID: 5902 Comm: bash Kdump: loaded Not tainted 6.14.0-rc5+ #138
Hardware name: IBM,9043-MRX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_028) hv:phyp pSeries
Call Trace:
[c0000000721ef590] [c00000000118f8a8] dump_stack_lvl+0x108/0x18c (unreliable)
[c0000000721ef5c0] [c00000000022563c] print_circular_bug+0x448/0x604
[c0000000721ef670] [c000000000225a44] check_noncircular+0x24c/0x26c
[c0000000721ef740] [c00000000022bf28] __lock_acquire+0x1b6c/0x2ae0
[c0000000721ef870] [c000000000229240] lock_acquire+0x140/0x430
[c0000000721ef970] [c0000000011cfbec] __mutex_lock+0xf0/0xa58
[c0000000721efaa0] [c00000000096c46c] wbt_init+0x164/0x238
[c0000000721efaf0] [c0000000008f8cd8] queue_wb_lat_store+0x1dc/0x20c
[c0000000721efb50] [c0000000008f8fa0] queue_attr_store+0x12c/0x164
[c0000000721efc60] [c0000000007c11cc] sysfs_kf_write+0x6c/0xb0
[c0000000721efca0] [c0000000007bfa4c] kernfs_fop_write_iter+0x1b8/0x29c
[c0000000721efcf0] [c0000000006a281c] vfs_write+0x410/0x584
[c0000000721efdc0] [c0000000006a2cc8] ksys_write+0x84/0x140
[c0000000721efe10] [c000000000031b64] system_call_exception+0x134/0x360
[c0000000721efe50] [c00000000000cedc] system_call_vectored_common+0x15c/0x2ec
>From the above log it's apparent that method which writes to sysfs attr
wbt_lat_usec acquires q->elevator_lock first, and then acquires q->rq_
qos_mutex. However the another method which writes to io.cost.qos,
acquires q->rq_qos_mutex first, and then acquires q->rq_qos_mutex. So
this could potentially cause the deadlock.
A closer look at ioc_qos_write shows that correcting the lock order is
non-trivial because q->rq_qos_mutex is acquired in blkg_conf_open_bdev
and released in blkg_conf_exit. The function blkg_conf_open_bdev is
responsible for parsing user input and finding the corresponding block
device (bdev) from the user provided major:minor number.
Since we do not know the bdev until blkg_conf_open_bdev completes, we
cannot simply move q->elevator_lock acquisition before blkg_conf_open_
bdev. So to address this, we intoduce new helpers blkg_conf_open_bdev_
frozen and blkg_conf_exit_frozen which are just wrappers around blkg_
conf_open_bdev and blkg_conf_exit respectively. The helper blkg_conf_
open_bdev_frozen is similar to blkg_conf_open_bdev, but additionally
freezes the queue, acquires q->elevator_lock and ensures the correct
locking order is followed between q->elevator_lock and q->rq_qos_mutex.
Similarly another helper blkg_conf_exit_frozen in addition to unfreezing
the queue ensures that we release the locks in correct order.
By using these helpers, now we maintain the same locking order in all
code paths where we update blk-wbt parameters.
Fixes: 245618f8e45f ("block: protect wbt_lat_usec using q->elevator_lock")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202503171650.cc082b66-lkp@intel.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250319105518.468941-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The ioc_qos_write method acquires q->elevator_lock to protect
updates to blk-wbt parameters. Once these updates are complete,
the lock should be released before returning from ioc_qos_write.
However, in one code path, the release of q->elevator_lock was
mistakenly omitted, potentially leading to a lock leak. This commit
fixes the issue by ensuring that q->elevator_lock is properly
released in all return paths of ioc_qos_write.
Fixes: 245618f8e45f ("block: protect wbt_lat_usec using q->elevator_lock")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202503171650.cc082b66-lkp@intel.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250319105518.468941-2-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The current I/O dispatch mechanism - queueing I/O by adding it to the
io_cmds list (and poking task_work as needed), then dispatching it in
ublk server task context by reversing io_cmds and completing the
io_uring command associated to each one - was introduced by commit
7d4a93176e014 ("ublk_drv: don't forward io commands in reserve order")
to ensure that the ublk server received I/O in the same order that the
block layer submitted it to ublk_drv. This mechanism was only needed for
the "raw" task_work submission mechanism, since the io_uring task work
wrapper maintains FIFO ordering (using quite a similar mechanism in
fact). The "raw" task_work submission mechanism is no longer supported
in ublk_drv as of commit 29dc5d06613f2 ("ublk: kill queuing request by
task_work_add"), so the explicit llist/reversal is no longer needed - it
just duplicates logic already present in the underlying io_uring APIs.
Remove it.
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250318-ublk_io_cmds-v1-1-c1bb74798fef@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This patch improve the returned error code of blkcg_policy_register().
1. Move the validation check for cpd/pd_alloc_fn and cpd/pd_free_fn
function pairs to the start of blkcg_policy_register(). This ensures
we immediately return -EINVAL if the function pairs are not correctly
provided, rather than returning -ENOSPC after locking and unlocking
mutexes unnecessarily.
Those locks should not contention any problems, as error of policy
registration is a super cold path.
2. Return -ENOMEM when cpd_alloc_fn() failed.
Co-authored-by: Wen Tao <wentao@uniontech.com>
Signed-off-by: Wen Tao <wentao@uniontech.com>
Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/3E333A73B6B6DFC0+20250317022924.150907-1-chenlinxuan@uniontech.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If vfs_flush() is called with queue frozen, the queue freeze lock may be
connected with FS internal lock, and lockdep warning can be triggered
because the queue freeze lock is connected with too many global or
sub-system locks.
Fix the warning by moving vfs_fsync() out of loop_update_dio():
- vfs_fsync() is only needed when switching to dio
- only loop_change_fd() and loop_configure() may switch from buffered
IO to direct IO, so call vfs_fsync() directly here. This way is safe
because either loop is in unbound, or new file isn't attached
- for the other two cases of set_status and set_block_size, direct IO
can only become off, so no need to call vfs_fsync()
Cc: Christoph Hellwig <hch@infradead.org>
Reported-by: Kun Hu <huk23@m.fudan.edu.cn>
Reported-by: Jiaji Qin <jjtan24@m.fudan.edu.cn>
Closes: https://lore.kernel.org/linux-block/359BC288-B0B1-4815-9F01-3A349B12E816@m.fudan.edu.cn/T/#u
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250318072955.3893805-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In recent kernels, there are lockdep splats around the
struct request_queue::io_lockdep_map, similar to [1], but they
typically don't show up until reclaim with writeback happens.
Having multiple kernel versions released with a known risc of kernel
deadlock during reclaim writeback should IMHO be addressed and
backported to -stable with the highest priority.
In order to have these lockdep splats show up earlier,
preferrably during system initialization, prime the
struct request_queue::io_lockdep_map as GFP_KERNEL reclaim-
tainted. This will instead lead to lockdep splats looking similar
to [2], but without the need for reclaim + writeback
happening.
[1]:
[ 189.762244] ======================================================
[ 189.762432] WARNING: possible circular locking dependency detected
[ 189.762441] 6.14.0-rc6-xe+ #6 Tainted: G U
[ 189.762450] ------------------------------------------------------
[ 189.762459] kswapd0/119 is trying to acquire lock:
[ 189.762467] ffff888110ceb710 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: __submit_bio+0x76/0x230
[ 189.762485]
but task is already holding lock:
[ 189.762494] ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00
[ 189.762507]
which lock already depends on the new lock.
[ 189.762519]
the existing dependency chain (in reverse order) is:
[ 189.762529]
-> #2 (fs_reclaim){+.+.}-{0:0}:
[ 189.762540] fs_reclaim_acquire+0xc5/0x100
[ 189.762548] kmem_cache_alloc_lru_noprof+0x4a/0x480
[ 189.762558] alloc_inode+0xaa/0xe0
[ 189.762566] iget_locked+0x157/0x330
[ 189.762573] kernfs_get_inode+0x1b/0x110
[ 189.762582] kernfs_get_tree+0x1b0/0x2e0
[ 189.762590] sysfs_get_tree+0x1f/0x60
[ 189.762597] vfs_get_tree+0x2a/0xf0
[ 189.762605] path_mount+0x4cd/0xc00
[ 189.762613] __x64_sys_mount+0x119/0x150
[ 189.762621] x64_sys_call+0x14f2/0x2310
[ 189.762630] do_syscall_64+0x91/0x180
[ 189.762637] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 189.762647]
-> #1 (&root->kernfs_rwsem){++++}-{3:3}:
[ 189.762659] down_write+0x3e/0xf0
[ 189.762667] kernfs_remove+0x32/0x60
[ 189.762676] sysfs_remove_dir+0x4f/0x60
[ 189.762685] __kobject_del+0x33/0xa0
[ 189.762709] kobject_del+0x13/0x30
[ 189.762716] elv_unregister_queue+0x52/0x80
[ 189.762725] elevator_switch+0x68/0x360
[ 189.762733] elv_iosched_store+0x14b/0x1b0
[ 189.762756] queue_attr_store+0x181/0x1e0
[ 189.762765] sysfs_kf_write+0x49/0x80
[ 189.762773] kernfs_fop_write_iter+0x17d/0x250
[ 189.762781] vfs_write+0x281/0x540
[ 189.762790] ksys_write+0x72/0xf0
[ 189.762798] __x64_sys_write+0x19/0x30
[ 189.762807] x64_sys_call+0x2a3/0x2310
[ 189.762815] do_syscall_64+0x91/0x180
[ 189.762823] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 189.762833]
-> #0 (&q->q_usage_counter(io)#26){++++}-{0:0}:
[ 189.762845] __lock_acquire+0x1525/0x2760
[ 189.762854] lock_acquire+0xca/0x310
[ 189.762861] blk_mq_submit_bio+0x8a2/0xba0
[ 189.762870] __submit_bio+0x76/0x230
[ 189.762878] submit_bio_noacct_nocheck+0x323/0x430
[ 189.762888] submit_bio_noacct+0x2cc/0x620
[ 189.762896] submit_bio+0x38/0x110
[ 189.762904] __swap_writepage+0xf5/0x380
[ 189.762912] swap_writepage+0x3c7/0x600
[ 189.762920] shmem_writepage+0x3da/0x4f0
[ 189.762929] pageout+0x13f/0x310
[ 189.762937] shrink_folio_list+0x61c/0xf60
[ 189.763261] evict_folios+0x378/0xcd0
[ 189.763584] try_to_shrink_lruvec+0x1b0/0x360
[ 189.763946] shrink_one+0x10e/0x200
[ 189.764266] shrink_node+0xc02/0x1490
[ 189.764586] balance_pgdat+0x563/0xb00
[ 189.764934] kswapd+0x1e8/0x430
[ 189.765249] kthread+0x10b/0x260
[ 189.765559] ret_from_fork+0x44/0x70
[ 189.765889] ret_from_fork_asm+0x1a/0x30
[ 189.766198]
other info that might help us debug this:
[ 189.767089] Chain exists of:
&q->q_usage_counter(io)#26 --> &root->kernfs_rwsem --> fs_reclaim
[ 189.767971] Possible unsafe locking scenario:
[ 189.768555] CPU0 CPU1
[ 189.768849] ---- ----
[ 189.769136] lock(fs_reclaim);
[ 189.769421] lock(&root->kernfs_rwsem);
[ 189.769714] lock(fs_reclaim);
[ 189.770016] rlock(&q->q_usage_counter(io)#26);
[ 189.770305]
*** DEADLOCK ***
[ 189.771167] 1 lock held by kswapd0/119:
[ 189.771453] #0: ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00
[ 189.771770]
stack backtrace:
[ 189.772351] CPU: 4 UID: 0 PID: 119 Comm: kswapd0 Tainted: G U 6.14.0-rc6-xe+ #6
[ 189.772353] Tainted: [U]=USER
[ 189.772354] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[ 189.772354] Call Trace:
[ 189.772355] <TASK>
[ 189.772356] dump_stack_lvl+0x6e/0xa0
[ 189.772359] dump_stack+0x10/0x18
[ 189.772360] print_circular_bug.cold+0x17a/0x1b7
[ 189.772363] check_noncircular+0x13a/0x150
[ 189.772365] ? __pfx_stack_trace_consume_entry+0x10/0x10
[ 189.772368] __lock_acquire+0x1525/0x2760
[ 189.772368] ? ret_from_fork_asm+0x1a/0x30
[ 189.772371] lock_acquire+0xca/0x310
[ 189.772372] ? __submit_bio+0x76/0x230
[ 189.772375] ? lock_release+0xd5/0x2c0
[ 189.772376] blk_mq_submit_bio+0x8a2/0xba0
[ 189.772378] ? __submit_bio+0x76/0x230
[ 189.772380] __submit_bio+0x76/0x230
[ 189.772382] ? trace_hardirqs_on+0x1e/0xe0
[ 189.772384] submit_bio_noacct_nocheck+0x323/0x430
[ 189.772386] ? submit_bio_noacct_nocheck+0x323/0x430
[ 189.772387] ? __might_sleep+0x58/0xa0
[ 189.772390] submit_bio_noacct+0x2cc/0x620
[ 189.772391] ? count_memcg_events+0x68/0x90
[ 189.772393] submit_bio+0x38/0x110
[ 189.772395] __swap_writepage+0xf5/0x380
[ 189.772396] swap_writepage+0x3c7/0x600
[ 189.772397] shmem_writepage+0x3da/0x4f0
[ 189.772401] pageout+0x13f/0x310
[ 189.772406] shrink_folio_list+0x61c/0xf60
[ 189.772409] ? isolate_folios+0xe80/0x16b0
[ 189.772410] ? mark_held_locks+0x46/0x90
[ 189.772412] evict_folios+0x378/0xcd0
[ 189.772414] ? evict_folios+0x34a/0xcd0
[ 189.772415] ? lock_is_held_type+0xa3/0x130
[ 189.772417] try_to_shrink_lruvec+0x1b0/0x360
[ 189.772420] shrink_one+0x10e/0x200
[ 189.772421] shrink_node+0xc02/0x1490
[ 189.772423] ? shrink_node+0xa08/0x1490
[ 189.772424] ? shrink_node+0xbd8/0x1490
[ 189.772425] ? mem_cgroup_iter+0x366/0x480
[ 189.772427] balance_pgdat+0x563/0xb00
[ 189.772428] ? balance_pgdat+0x563/0xb00
[ 189.772430] ? trace_hardirqs_on+0x1e/0xe0
[ 189.772431] ? finish_task_switch.isra.0+0xcb/0x330
[ 189.772433] ? __switch_to_asm+0x33/0x70
[ 189.772437] kswapd+0x1e8/0x430
[ 189.772438] ? __pfx_autoremove_wake_function+0x10/0x10
[ 189.772440] ? __pfx_kswapd+0x10/0x10
[ 189.772441] kthread+0x10b/0x260
[ 189.772443] ? __pfx_kthread+0x10/0x10
[ 189.772444] ret_from_fork+0x44/0x70
[ 189.772446] ? __pfx_kthread+0x10/0x10
[ 189.772447] ret_from_fork_asm+0x1a/0x30
[ 189.772450] </TASK>
[2]:
[ 8.760253] ======================================================
[ 8.760254] WARNING: possible circular locking dependency detected
[ 8.760255] 6.14.0-rc6-xe+ #7 Tainted: G U
[ 8.760256] ------------------------------------------------------
[ 8.760257] (udev-worker)/674 is trying to acquire lock:
[ 8.760259] ffff888100e39148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove+0x32/0x60
[ 8.760265]
but task is already holding lock:
[ 8.760266] ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[ 8.760272]
which lock already depends on the new lock.
[ 8.760272]
the existing dependency chain (in reverse order) is:
[ 8.760273]
-> #2 (&q->q_usage_counter(io)#27){++++}-{0:0}:
[ 8.760276] blk_alloc_queue+0x30a/0x350
[ 8.760279] blk_mq_alloc_queue+0x6b/0xe0
[ 8.760281] scsi_alloc_sdev+0x276/0x3c0
[ 8.760284] scsi_probe_and_add_lun+0x22a/0x440
[ 8.760286] __scsi_scan_target+0x109/0x230
[ 8.760288] scsi_scan_channel+0x65/0xc0
[ 8.760290] scsi_scan_host_selected+0xff/0x140
[ 8.760292] do_scsi_scan_host+0xa7/0xc0
[ 8.760293] do_scan_async+0x1c/0x160
[ 8.760295] async_run_entry_fn+0x32/0x150
[ 8.760299] process_one_work+0x224/0x5f0
[ 8.760302] worker_thread+0x1d4/0x3e0
[ 8.760304] kthread+0x10b/0x260
[ 8.760306] ret_from_fork+0x44/0x70
[ 8.760309] ret_from_fork_asm+0x1a/0x30
[ 8.760312]
-> #1 (fs_reclaim){+.+.}-{0:0}:
[ 8.760315] fs_reclaim_acquire+0xc5/0x100
[ 8.760317] kmem_cache_alloc_lru_noprof+0x4a/0x480
[ 8.760319] alloc_inode+0xaa/0xe0
[ 8.760322] iget_locked+0x157/0x330
[ 8.760323] kernfs_get_inode+0x1b/0x110
[ 8.760325] kernfs_get_tree+0x1b0/0x2e0
[ 8.760327] sysfs_get_tree+0x1f/0x60
[ 8.760329] vfs_get_tree+0x2a/0xf0
[ 8.760332] path_mount+0x4cd/0xc00
[ 8.760334] __x64_sys_mount+0x119/0x150
[ 8.760336] x64_sys_call+0x14f2/0x2310
[ 8.760338] do_syscall_64+0x91/0x180
[ 8.760340] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 8.760342]
-> #0 (&root->kernfs_rwsem){++++}-{3:3}:
[ 8.760345] __lock_acquire+0x1525/0x2760
[ 8.760347] lock_acquire+0xca/0x310
[ 8.760348] down_write+0x3e/0xf0
[ 8.760350] kernfs_remove+0x32/0x60
[ 8.760351] sysfs_remove_dir+0x4f/0x60
[ 8.760353] __kobject_del+0x33/0xa0
[ 8.760355] kobject_del+0x13/0x30
[ 8.760356] elv_unregister_queue+0x52/0x80
[ 8.760358] elevator_switch+0x68/0x360
[ 8.760360] elv_iosched_store+0x14b/0x1b0
[ 8.760362] queue_attr_store+0x181/0x1e0
[ 8.760364] sysfs_kf_write+0x49/0x80
[ 8.760366] kernfs_fop_write_iter+0x17d/0x250
[ 8.760367] vfs_write+0x281/0x540
[ 8.760370] ksys_write+0x72/0xf0
[ 8.760372] __x64_sys_write+0x19/0x30
[ 8.760374] x64_sys_call+0x2a3/0x2310
[ 8.760376] do_syscall_64+0x91/0x180
[ 8.760377] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 8.760380]
other info that might help us debug this:
[ 8.760380] Chain exists of:
&root->kernfs_rwsem --> fs_reclaim --> &q->q_usage_counter(io)#27
[ 8.760384] Possible unsafe locking scenario:
[ 8.760384] CPU0 CPU1
[ 8.760385] ---- ----
[ 8.760385] lock(&q->q_usage_counter(io)#27);
[ 8.760387] lock(fs_reclaim);
[ 8.760388] lock(&q->q_usage_counter(io)#27);
[ 8.760390] lock(&root->kernfs_rwsem);
[ 8.760391]
*** DEADLOCK ***
[ 8.760391] 6 locks held by (udev-worker)/674:
[ 8.760392] #0: ffff8881209ac420 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
[ 8.760398] #1: ffff88810c80f488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x136/0x250
[ 8.760402] #2: ffff888125d1d330 (kn->active#101){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x13f/0x250
[ 8.760406] #3: ffff888110dc7bb0 (&q->sysfs_lock){+.+.}-{3:3}, at: queue_attr_store+0x148/0x1e0
[ 8.760411] #4: ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[ 8.760416] #5: ffff888110dc76b8 (&q->q_usage_counter(queue)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[ 8.760421]
stack backtrace:
[ 8.760422] CPU: 7 UID: 0 PID: 674 Comm: (udev-worker) Tainted: G U 6.14.0-rc6-xe+ #7
[ 8.760424] Tainted: [U]=USER
[ 8.760425] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[ 8.760426] Call Trace:
[ 8.760427] <TASK>
[ 8.760428] dump_stack_lvl+0x6e/0xa0
[ 8.760431] dump_stack+0x10/0x18
[ 8.760433] print_circular_bug.cold+0x17a/0x1b7
[ 8.760437] check_noncircular+0x13a/0x150
[ 8.760441] ? save_trace+0x54/0x360
[ 8.760445] __lock_acquire+0x1525/0x2760
[ 8.760446] ? irqentry_exit+0x3a/0xb0
[ 8.760448] ? sysvec_apic_timer_interrupt+0x57/0xc0
[ 8.760452] lock_acquire+0xca/0x310
[ 8.760453] ? kernfs_remove+0x32/0x60
[ 8.760457] down_write+0x3e/0xf0
[ 8.760459] ? kernfs_remove+0x32/0x60
[ 8.760460] kernfs_remove+0x32/0x60
[ 8.760462] sysfs_remove_dir+0x4f/0x60
[ 8.760464] __kobject_del+0x33/0xa0
[ 8.760466] kobject_del+0x13/0x30
[ 8.760467] elv_unregister_queue+0x52/0x80
[ 8.760470] elevator_switch+0x68/0x360
[ 8.760472] elv_iosched_store+0x14b/0x1b0
[ 8.760475] queue_attr_store+0x181/0x1e0
[ 8.760479] ? lock_acquire+0xca/0x310
[ 8.760480] ? kernfs_fop_write_iter+0x13f/0x250
[ 8.760482] ? lock_is_held_type+0xa3/0x130
[ 8.760485] sysfs_kf_write+0x49/0x80
[ 8.760487] kernfs_fop_write_iter+0x17d/0x250
[ 8.760489] vfs_write+0x281/0x540
[ 8.760494] ksys_write+0x72/0xf0
[ 8.760497] __x64_sys_write+0x19/0x30
[ 8.760499] x64_sys_call+0x2a3/0x2310
[ 8.760502] do_syscall_64+0x91/0x180
[ 8.760504] ? trace_hardirqs_off+0x5d/0xe0
[ 8.760506] ? handle_softirqs+0x479/0x4d0
[ 8.760508] ? hrtimer_interrupt+0x13f/0x280
[ 8.760511] ? irqentry_exit_to_user_mode+0x8b/0x260
[ 8.760513] ? clear_bhb_loop+0x15/0x70
[ 8.760515] ? clear_bhb_loop+0x15/0x70
[ 8.760516] ? clear_bhb_loop+0x15/0x70
[ 8.760518] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 8.760520] RIP: 0033:0x7aa3bf2f5504
[ 8.760522] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 8b 10 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
[ 8.760523] RSP: 002b:00007ffc1e3697d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[ 8.760526] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007aa3bf2f5504
[ 8.760527] RDX: 0000000000000003 RSI: 00007ffc1e369ae0 RDI: 000000000000001c
[ 8.760528] RBP: 00007ffc1e369800 R08: 00007aa3bf3f51c8 R09: 00007ffc1e3698b0
[ 8.760528] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
[ 8.760529] R13: 00007ffc1e369ae0 R14: 0000613ccf21f2f0 R15: 00007aa3bf3f4e80
[ 8.760533] </TASK>
v2:
- Update a code comment to increase readability (Ming Lei).
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250318095548.5187-1-thomas.hellstrom@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
queue_ra_entry uses limits_lock just like the attributes above it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250312150127.703534-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
The hctx_busy_show method in debugfs is currently unprotected. This
method iterates over all started requests in a tagset and prints them.
However, the tags can be updated concurrently via the sysfs attributes
'nr_requests' or 'scheduler' (elevator switch), leading to potential
race conditions.
Since sysfs attributes 'nr_requests' and 'scheduler' are already
protected using q->elevator_lock, extend this protection to the debugfs
'busy' attribute as well to ensure consistency.
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250313115235.3707600-4-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
In some debugfs attribute read methods, failure to acquire the mutex
lock results in jumping to a label before returning an error code.
However this is unnecessary, as we can return the failure code directly,
improving code readability and reducing complexity.
This commit removes the goto labels and ensures that the method returns
immediately upon failing to acquire the mutex lock.
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250313115235.3707600-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Currently, the block debugfs attributes (tags, tags_bitmap, sched_tags,
and sched_tags_bitmap) are protected using q->sysfs_lock. However, these
attributes are updated in multiple scenarios:
- During driver probe method
- During an elevator switch/update
- During an nr_hw_queues update
- When writing to the sysfs attribute nr_requests
All these update paths (except driver probe method, which doesn't
require any protection) are already protected using q->elevator_lock. To
ensure consistency and proper synchronization, replace q->sysfs_lock
with q->elevator_lock for protecting these debugfs attributes.
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250313115235.3707600-2-nilay@linux.ibm.com
[axboe: some commit message rewording/fixes]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
request_queue param is no longer used by blk_rq_map_sg and
__blk_rq_map_sg. Remove it.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250313035322.243239-1-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
>4GB folio is possible on some ARCHs, such as aarch64, 16GB hugepage
is supported, then 'offset' of folio can't be held in 'unsigned int',
cause warning in bio_add_folio_nofail() and IO failure.
Fix it by adjusting 'page' & trimming 'offset' so that `->bi_offset` won't
be overflow, and folio can be added to bio successfully.
Fixes: ed9832bc08db ("block: introduce folio awareness and add a bigger size from folio")
Cc: Kundan Kumar <kundan.kumar@samsung.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Gavin Shan <gshan@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20250312145136.2891229-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
The blk_mq_map_queue()'s request_queue param is not used anymore,
remove it, same with blk_get_flush_queue().
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250312084722.129680-1-kanie@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
In _badblocks_check(), there are lines of code like this,
1246 sectors -= len;
[snipped]
1251 WARN_ON(sectors < 0);
The WARN_ON() at line 1257 doesn't make sense because sectors is
unsigned long long type and never to be <0.
Fix it by checking directly checking whether sectors is less than len.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Coly Li <colyli@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250309160556.42854-1-colyli@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Make sure ->nr_integrity_segments is cloned in blk_rq_prep_clone(),
otherwise requests cloned by device-mapper multipath will not have the
proper nr_integrity_segments values set, then BUG() is hit from
sg_alloc_table_chained().
Fixes: b0fd271d5fba ("block: add request clone interface (v2)")
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250310115453.2271109-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Currently, hctx attributes (nr_tags, nr_reserved_tags, and cpu_list)
are protected using `q->sysfs_lock`. However, these attributes can be
updated in multiple scenarios:
- During the driver's probe method.
- When updating nr_hw_queues.
- When writing to the sysfs attribute nr_requests,
which can modify nr_tags.
The nr_requests attribute is already protected using q->elevator_lock,
but none of the update paths actually use q->sysfs_lock to protect hctx
attributes. So to ensure proper synchronization, replace q->sysfs_lock
with q->elevator_lock when reading hctx attributes through sysfs.
Additionally, blk_mq_update_nr_hw_queues allocates and updates hctx.
The allocation of hctx is protected using q->elevator_lock, however,
updating hctx params happens without any protection, so safeguard hctx
param update path by also using q->elevator_lock.
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250306093956.2818808-1-nilay@linux.ibm.com
[axboe: wrap comment at 80 chars]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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The bdi->ra_pages could be updated under q->limits_lock because it's
usually calculated from the queue limits by queue_limits_commit_update.
So protect reading/writing the sysfs attribute read_ahead_kb using
q->limits_lock instead of q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-8-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The wbt latency and state could be updated while initializing the
elevator or exiting the elevator. It could be also updated while
configuring IO latency QoS parameters using cgroup. The elevator
code path is now protected with q->elevator_lock. So we should
protect the access to sysfs attribute wbt_lat_usec using q->elevator
_lock instead of q->sysfs_lock. White we're at it, also protect
ioc_qos_write(), which configures wbt parameters via cgroup, using
q->elevator_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-7-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The sysfs attribute nr_requests could be simultaneously updated from
elevator switch/update or nr_hw_queue update code path. The update to
nr_requests for each of those code paths runs holding q->elevator_lock.
So we should protect access to sysfs attribute nr_requests using q->
elevator_lock instead of q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-6-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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A queue's elevator can be updated either when modifying nr_hw_queues
or through the sysfs scheduler attribute. Currently, elevator switching/
updating is protected using q->sysfs_lock, but this has led to lockdep
splats[1] due to inconsistent lock ordering between q->sysfs_lock and
the freeze-lock in multiple block layer call sites.
As the scope of q->sysfs_lock is not well-defined, its (mis)use has
resulted in numerous lockdep warnings. To address this, introduce a new
q->elevator_lock, dedicated specifically for protecting elevator
switches/updates. And we'd now use this new q->elevator_lock instead of
q->sysfs_lock for protecting elevator switches/updates.
While at it, make elv_iosched_load_module() a static function, as it is
only called from elv_iosched_store(). Also, remove redundant parameters
from elv_iosched_load_module() function signature.
[1] https://lore.kernel.org/all/67637e70.050a0220.3157ee.000c.GAE@google.com/
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-5-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There're few sysfs attributes in block layer which don't really need
acquiring q->sysfs_lock while accessing it. The reason being, reading/
writing a value from/to such attributes are either atomic or could be
easily protected using READ_ONCE()/WRITE_ONCE(). Moreover, sysfs
attributes are inherently protected with sysfs/kernfs internal locking.
So this change help segregate all existing sysfs attributes for which
we could avoid acquiring q->sysfs_lock. For all read-only attributes
we removed the q->sysfs_lock from show method of such attributes. In
case attribute is read/write then we removed the q->sysfs_lock from
both show and store methods of these attributes.
We audited all block sysfs attributes and found following list of
attributes which shouldn't require q->sysfs_lock protection:
1. io_poll:
Write to this attribute is ignored. So, we don't need q->sysfs_lock.
2. io_poll_delay:
Write to this attribute is NOP, so we don't need q->sysfs_lock.
3. io_timeout:
Write to this attribute updates q->rq_timeout and read of this
attribute returns the value stored in q->rq_timeout Moreover, the
q->rq_timeout is set only once when we init the queue (under blk_mq_
init_allocated_queue()) even before disk is added. So that means
that we don't need to protect it with q->sysfs_lock. As this
attribute is not directly correlated with anything else simply using
READ_ONCE/WRITE_ONCE should be enough.
4. nomerges:
Write to this attribute file updates two q->flags : QUEUE_FLAG_
NOMERGES and QUEUE_FLAG_NOXMERGES. These flags are accessed during
bio-merge which anyways doesn't run with q->sysfs_lock held.
Moreover, the q->flags are updated/accessed with bitops which are
atomic. So, protecting it with q->sysfs_lock is not necessary.
5. rq_affinity:
Write to this attribute file makes atomic updates to q->flags:
QUEUE_FLAG_SAME_COMP and QUEUE_FLAG_SAME_FORCE. These flags are
also accessed from blk_mq_complete_need_ipi() using test_bit macro.
As read/write to q->flags uses bitops which are atomic, protecting
it with q->stsys_lock is not necessary.
6. nr_zones:
Write to this attribute happens in the driver probe method (except
nvme) before disk is added and outside of q->sysfs_lock or any other
lock. Moreover nr_zones is defined as "unsigned int" and so reading
this attribute, even when it's simultaneously being updated on other
cpu, should not return torn value on any architecture supported by
linux. So we can avoid using q->sysfs_lock or any other lock/
protection while reading this attribute.
7. discard_zeroes_data:
Reading of this attribute always returns 0, so we don't require
holding q->sysfs_lock.
8. write_same_max_bytes
Reading of this attribute always returns 0, so we don't require
holding q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-4-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In preparation to further simplify and group sysfs attributes which
don't require locking or require some form of locking other than q->
limits_lock, move acquire/release of q->sysfs_lock and queue freeze/
unfreeze under each attributes' respective show/store method.
While we are at it, also remove ->load_module() as it's used to load
the module before queue is freezed. Now as we moved queue-freeze under
->store(), we could load module directly from the attributes' store
method before we actually start freezing the queue. Currently, the
->load_module() is only used by "scheduler" attribute, so we now load
the relevant elevator module before we start freezing the queue in
elv_iosched_store().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There're few sysfs attributes(RW) whose store method is protected
with q->limits_lock, however the corresponding show method of these
attributes run holding q->sysfs_lock and that doesn't make sense
as ideally the show method of these attributes should also run
holding q->limits_lock instead of q->sysfs_lock. Hence update the
show method of these sysfs attributes so that reading of these
attributes acquire q->limits_lock instead of q->sysfs_lock.
Similarly, there're few sysfs attributes(RO) whose show method is
currently protected with q->sysfs_lock however updates to these
attributes could occur using atomic limit update APIs such as queue_
limits_start_update() and queue_limits_commit_update() which run
holding q->limits_lock. So that means that reading these attributes
holding q->sysfs_lock doesn't make sense. Hence update the show method
of these sysfs attributes(RO) such that they run with holding q->
limits_lock instead of q->sysfs_lock.
We have defined a new macro QUEUE_LIM_RO_ENTRY() which uses new ->show_
limit() method and it runs holding q->limits_lock. All existing sysfs
attributes(RO) which needs protection using q->limits_lock while
reading have been now updated to use this new macro for initialization.
Also, the existing QUEUE_LIM_RW_ENTRY() is updated to use new ->show_
limit() method for reading attributes instead of existing ->show()
method. As ->show_limit() runs holding q->limits_lock, the existing
sysfs attributes(RW) requiring protection are now inherently protected
using q->limits_lock instead of q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250304102551.2533767-2-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is a truncation of badblocks length issue when set badblocks as
follow:
echo "2055 4294967299" > bad_blocks
cat bad_blocks
2055 3
Change 'sectors' argument type from 'int' to 'sector_t'.
This change avoids truncation of badblocks length for large sectors by
replacing 'int' with 'sector_t' (u64), enabling proper handling of larger
disk sizes and ensuring compatibility with 64-bit sector addressing.
Fixes: 9e0e252a048b ("badblocks: Add core badblock management code")
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-13-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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rdev_set_badblocks() only indicates success/failure, so convert its return
type from int to boolean for better semantic clarity.
rdev_clear_badblocks() return value is never used by any caller, convert it
to void. This removes unnecessary value returns.
Also update narrow_write_error() in both raid1 and raid10 to use boolean
return type to match rdev_set_badblocks().
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250227075507.151331-12-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Change the return type of badblocks_set() and badblocks_clear()
from int to bool, indicating success or failure. Specifically:
- _badblocks_set() and _badblocks_clear() functions now return
true for success and false for failure.
- All calls to these functions are updated to handle the new
boolean return type.
- This change improves code clarity and ensures a more consistent
handling of success and failure states.
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Acked-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20250227075507.151331-11-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The bad blocks check would miss bad blocks when retrying under contention,
as checking parameters are not reset. These stale values from the previous
attempt could lead to incorrect scanning in the subsequent retry.
Move seqlock to outer function and reinitialize checking state for each
retry. This ensures a clean state for each check attempt, preventing any
missed bad blocks.
Fixes: 3ea3354cb9f0 ("badblocks: improve badblocks_check() for multiple ranges handling")
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-10-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is a merge issue when adding badblocks as follow:
echo 0 10 > bad_blocks
echo 30 10 > bad_blocks
echo 20 10 > bad_blocks
cat bad_blocks
0 10
20 10 //should be merged with (30 10)
30 10
In this case, if new badblocks does not intersect with prev, it is added
by insert_at(). If there is an intersection with prev+1, the merge will
be processed in the next re_insert loop.
However, when the end of the new badblocks is exactly equal to the offset
of prev+1, no further re_insert loop occurs, and the two badblocks are not
merge.
Fix it by inc prev, badblocks can be merged during the subsequent code.
Fixes: aa511ff8218b ("badblocks: switch to the improved badblock handling code")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250227075507.151331-9-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Regardless of whether overlap_front() returns true or false,
can_merge_front() will be executed first. Therefore, move
can_merge_front() in front of can_merge_front() to simplify code.
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250227075507.151331-8-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The number of badblocks cannot exceed MAX_BADBLOCKS, but it should be
allowed to equal MAX_BADBLOCKS.
Fixes: aa511ff8218b ("badblocks: switch to the improved badblock handling code")
Fixes: c3c6a86e9efc ("badblocks: add helper routines for badblock ranges handling")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-7-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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_badblocks_set() returns success if at least one badblock is set
successfully, even if others fail. This can lead to data inconsistencies
in raid, where a failed badblock set should trigger the disk to be kicked
out to prevent future reads from failed write areas.
_badblocks_set() should return error if any badblock set fails. Instead
of relying on 'rv', directly returning 'sectors' for clearer logic. If all
badblocks are successfully set, 'sectors' will be 0, otherwise it
indicates the number of badblocks that have not been set yet, thus
signaling failure.
By the way, it can also fix an issue: when a newly set unack badblock is
included in an existing ack badblock, the setting will return an error.
···
echo "0 100" /sys/block/md0/md/dev-loop1/bad_blocks
echo "0 100" /sys/block/md0/md/dev-loop1/unacknowledged_bad_blocks
-bash: echo: write error: No space left on device
```
After fix, it will return success.
Fixes: aa511ff8218b ("badblocks: switch to the improved badblock handling code")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-6-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In the current handling of badblocks settings, a lot of processing has
been done for scenarios where the number of badblocks exceeds 512.
This makes the code look quite complex and also introduces some issues,
For example, if there is 512 badblocks already:
for((i=0; i<510; i++)); do ((sector=i*2)); echo "$sector 1" > bad_blocks; done
echo 2100 10 > bad_blocks
echo 2200 10 > bad_blocks
Set new one, exceed 512:
echo 2000 500 > bad_blocks
Expected:
2000 500
Actual:
2100 400
In fact, a disk shouldn't have too many badblocks, and for disks with
512 badblocks, attempting to set more bad blocks doesn't make much sense.
At that point, the more appropriate action would be to replace the disk.
Therefore, to resolve these issues and simplify the code somewhat, return
error directly when setting badblocks exceeds 512.
Fixes: aa511ff8218b ("badblocks: switch to the improved badblock handling code")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250227075507.151331-5-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If ack and unack badblocks are adjacent, they will not be merged and will
remain as two separate badblocks. Even after the bad blocks are written
to disk and both become ack, they will still remain as two independent
bad blocks. This is not ideal as it wastes the limited space for
badblocks. Therefore, during ack_all_badblocks(), attempt to merge
badblocks if they are adjacent.
Fixes: aa511ff8218b ("badblocks: switch to the improved badblock handling code")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-4-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
Baruch Siach
Qasim Ijaz
Nilay Shroff
Hannes Reinecke
Milan Broz
Jens Axboe
Uday Shankar
Chen Linxuan
Ming Lei
Thomas Hellström
Christoph Hellwig
Anuj Gupta
Guixin Liu
Coly Li
Zheng Qixing
Li Nan