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| author | Rob Herring (Arm) <robh@kernel.org> | 2026-08-31 14:43:51 -0500 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2026-09-13 18:17:31 -0700 |
| commit | 55fc280e951ab2b39f3dcb640edc1b1eebc6d173 (patch) | |
| tree | f0b5f37b42fc13b9908a31b657c646b024231cdd /Documentation/admin-guide/device-mapper/kcopyd.rst | |
| download | linux-stable-55fc280e951ab2b39f3dcb640edc1b1eebc6d173.tar.gz linux-stable-55fc280e951ab2b39f3dcb640edc1b1eebc6d173.zip | |
Input: tsc2007 - read "ti,poll-period" as u32grafted
The "ti,poll-period" property is documented as a normal uint32 cell.
The driver used a u64 helper, which makes the helper type disagree with
the schema even though the stored value is still small.
Read "ti,poll-period" with the u32 helper matching the documented DT
cell size.
Assisted-by: Codex:gpt-5-5
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260831194352.1185860-1-robh@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'Documentation/admin-guide/device-mapper/kcopyd.rst')
| -rw-r--r-- | Documentation/admin-guide/device-mapper/kcopyd.rst | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/admin-guide/device-mapper/kcopyd.rst b/Documentation/admin-guide/device-mapper/kcopyd.rst new file mode 100644 index 000000000..7651d3951 --- /dev/null +++ b/Documentation/admin-guide/device-mapper/kcopyd.rst @@ -0,0 +1,47 @@ +====== +kcopyd +====== + +Kcopyd provides the ability to copy a range of sectors from one block-device +to one or more other block-devices, with an asynchronous completion +notification. It is used by dm-snapshot and dm-mirror. + +Users of kcopyd must first create a client and indicate how many memory pages +to set aside for their copy jobs. This is done with a call to +kcopyd_client_create():: + + int kcopyd_client_create(unsigned int num_pages, + struct kcopyd_client **result); + +To start a copy job, the user must set up io_region structures to describe +the source and destinations of the copy. Each io_region indicates a +block-device along with the starting sector and size of the region. The source +of the copy is given as one io_region structure, and the destinations of the +copy are given as an array of io_region structures:: + + struct io_region { + struct block_device *bdev; + sector_t sector; + sector_t count; + }; + +To start the copy, the user calls kcopyd_copy(), passing in the client +pointer, pointers to the source and destination io_regions, the name of a +completion callback routine, and a pointer to some context data for the copy:: + + int kcopyd_copy(struct kcopyd_client *kc, struct io_region *from, + unsigned int num_dests, struct io_region *dests, + unsigned int flags, kcopyd_notify_fn fn, void *context); + + typedef void (*kcopyd_notify_fn)(int read_err, unsigned int write_err, + void *context); + +When the copy completes, kcopyd will call the user's completion routine, +passing back the user's context pointer. It will also indicate if a read or +write error occurred during the copy. + +When a user is done with all their copy jobs, they should call +kcopyd_client_destroy() to delete the kcopyd client, which will release the +associated memory pages:: + + void kcopyd_client_destroy(struct kcopyd_client *kc); |
