kernel/linux.git/drivers/md/dm-delay.c, branch v7.0-rc7

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

dm: add WQ_PERCPU to alloc_workqueue users

2026-01-14T12:16:00+00:00

This continues the effort to refactor workqueue APIs, which began with the introduction of new workqueues and a new alloc_workqueue flag in: commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") The refactoring is going to alter the default behavior of alloc_workqueue() to be unbound by default. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. For more details see the Link tag below. In order to keep alloc_workqueue() behavior identical, explicitly request WQ_PERCPU. Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/ Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Signed-off-by: Mikulas Patocka

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

dm-delay: don't busy-wait in kthread

2025-05-04T09:35:05+00:00

When using a kthread to delay the IOs, dm-delay would continuously loop, checking if IOs were ready to submit. It had a cond_resched() call in the loop, but might still loop hundreds of millions of times waiting for an IO that was scheduled to be submitted 10s of ms in the future. With the change to make dm-delay over zoned devices always use kthreads regardless of the length of the delay, this wasted work only gets worse. To solve this and still keep roughly the same precision for very short delays, dm-delay now calls fsleep() for 1/8th of the smallest non-zero delay it will place on IOs, or 1 ms, whichever is smaller. The reason that dm-delay doesn't just use the actual expiration time of the next delayed IO to calculated the sleep time is that delay_dtr() must wait for the kthread to finish before deleting the table. If a zoned device with a long delay queued an IO shortly before being suspended and removed, the IO would be flushed in delay_presuspend(), but the removing the device would still have to wait for the remainder of the long delay. This time is now capped at 1 ms. Signed-off-by: Benjamin Marzinski Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Mikulas Patocka

dm-delay: support zoned devices

2025-03-24T17:28:32+00:00

Add support for zoned device by passing through report_zoned to the underlying read device. This is required to make enable xfstests xfs/311 on zoned devices. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Signed-off-by: Mikulas Patocka

dm-delay: remove timer_lock

2024-05-09T13:10:58+00:00

Instead of manually checking the timer details in queue_timeout(), call timer_reduce() to start the timer or reduce the expiration time. This avoids needing a lock. Signed-off-by: Benjamin Marzinski Signed-off-by: Mike Snitzer

dm-delay: change locking to avoid contention

2024-05-09T13:10:58+00:00

The delayed_bios list is protected by one mutex shared by all dm-delay devices. This mutex must be held whenever a bio is added or expired bios are removed from the list. Since a large number of expired bios could be on the list, flush_delayed_bios() can schedule while holding the mutex. This means a flush_delayed_bios() call on any dm-delay device can slow down delay_map() calls on any other dm-delay device. To keep dm-delay devices from slowing each other down and keep processing delay bios from slowing adding delayed bios, the global mutex has been removed, and each dm-delay device now has two locks. delayed_bios_lock is a spinlock that must be held whenever the delayed_bios list is accessed. process_bios_lock is a mutex that must be held whenever a process has temporarily pulled bios off the delayed_bios list to check which ones should be processed. It must be held until all the bios that won't be processed are returned to the list. This is what flush_delayed_bios() now does. The mutex is necessary to guarantee that delay_presuspend() sees the entire list of delayed bios when it calls flush_delayed_bios(). Signed-off-by: Benjamin Marzinski Signed-off-by: Mike Snitzer

dm-delay: fix max_delay calculations

2024-05-09T13:10:58+00:00

delay_ctr() pointlessly compared max_delay in cases where multiple delay classes were initialized identically. Also, when write delays were configured different than read delays, delay_ctr() never compared their value against max_delay. Fix these issues. Fixes: 70bbeb29fab0 ("dm delay: for short delays, use kthread instead of timers and wq") Signed-off-by: Benjamin Marzinski Signed-off-by: Mike Snitzer

dm-delay: fix hung task introduced by kthread mode

2024-05-09T13:10:58+00:00

If the worker thread is not woken due to a bio, then it is not woken at all. This causes the hung task check to trigger. This occurs, for instance, when no bios are submitted. Also when a delay of 0 is configured, delay_bio() returns without waking the worker. Prevent the hung task check from triggering by creating the thread with kthread_run() instead of using kthread_create() directly. Fixes: 70bbeb29fab0 ("dm delay: for short delays, use kthread instead of timers and wq") Signed-off-by: Joel Colledge Reviewed-by: Benjamin Marzinski Signed-off-by: Mike Snitzer