kernel/linux.git/include/uapi/linux/blktrace_api.h, branch v6.19.11

blktrace: add support for REQ_OP_WRITE_ZEROES tracing

2025-11-03T15:30:56+00:00

Currently, REQ_OP_WRITE_ZEROES operations are not handled in the blktrace infrastructure, resulting in incorrect or missing operation labels in ftrace blktrace output. This manifests as write-zeroes operations appearing with incorrect labels like "N" instead of a proper "WZ" designation. This patch adds complete support for REQ_OP_WRITE_ZEROES across the blktrace infrastructure: Add BLK_TC_WRITE_ZEROES trace category in blktrace_api.h and update BLK_TC_END_V2 marker accordingly Map REQ_OP_WRITE_ZEROES to BLK_TC_WRITE_ZEROES in __blk_add_trace() to ensure proper trace event categorization Update fill_rwbs() to generate "WZ" label for write-zeroes operations in ftrace output, making them easily identifiable Add "write-zeroes" string mapping in act_to_str array for debugfs filter interface Update blk_fill_rwbs() to handle REQ_OP_WRITE_ZEROES for block layer event tracing With this fix, write-zeroes operations are now correctly traced and displayed. =========================================================== BEFORE THIS PATCH =========================================================== blkdiscard -z -o 0 -l 40960 /dev/nvme0n1 blkdiscard-3809 [030] ..... 1212.253701: block_bio_queue: 259,0 NS 0 + 80 [blkdiscard] blkdiscard-3809 [030] ..... 1212.253703: block_getrq: 259,0 NS 0 + 80 [blkdiscard] blkdiscard-3809 [030] ..... 1212.253704: block_io_start: 259,0 NS 40960 () 0 + 80 be,0,4 [blkdiscard] blkdiscard-3809 [030] ..... 1212.253704: block_plug: [blkdiscard] blkdiscard-3809 [030] ..... 1212.253706: block_unplug: [blkdiscard] 1 blkdiscard-3809 [030] ..... 1212.253706: block_rq_insert: 259,0 NS 40960 () 0 + 80 be,0,4 [blkdiscard] kworker/30:1H-566 [030] ..... 1212.253726: block_rq_issue: 259,0 NS 40960 () 0 + 80 be,0,4 [kworker/30:1H] -0 [030] d.h1. 1212.253957: block_rq_complete: 259,0 NS () 0 + 80 be,0,4 [0] -0 [030] dNh1. 1212.253960: block_io_done: 259,0 NS 0 () 0 + 0 none,0,0 [swapper/30] Trace Event Breakdown: Event | Device | Op | Sector | Sectors | Byte Size | Calculation block_bio_queue | 259,0 | NS | 0 | 80 | - | 80 × 512 = 40,960 block_getrq | 259,0 | NS | 0 | 80 | - | 80 × 512 = 40,960 block_io_start | 259,0 | NS | 0 | 80 | 40960 | Direct from trace block_rq_insert | 259,0 | NS | 0 | 80 | 40960 | Direct from trace block_rq_issue | 259,0 | NS | 0 | 80 | 40960 | Direct from trace block_rq_complete | 259,0 | NS | 0 | 80 | - | 80 × 512 = 40,960 block_io_done | 259,0 | NS | 0 | 0 | 0 | Completion (no data) Total Bytes Transferred: Sectors: 80 Bytes: 80 × 512 = 40,960 bytes =========================================================== AFTER THIS PATCH =========================================================== blkdiscard -z -o 0 -l 40960 /dev/nvme0n1 blkdiscard-2477 [020] ..... 960.989131: block_bio_queue: 259,0 WZS 0 + 80 [blkdiscard] blkdiscard-2477 [020] ..... 960.989134: block_getrq: 259,0 WZS 0 + 80 [blkdiscard] blkdiscard-2477 [020] ..... 960.989135: block_io_start: 259,0 WZS 40960 () 0 + 80 be,0,4 [blkdiscard] blkdiscard-2477 [020] ..... 960.989138: block_plug: [blkdiscard] blkdiscard-2477 [020] ..... 960.989140: block_unplug: [blkdiscard] 1 blkdiscard-2477 [020] ..... 960.989141: block_rq_insert: 259,0 WZS 40960 () 0 + 80 be,0,4 [blkdiscard] kworker/20:1H-736 [020] ..... 960.989166: block_rq_issue: 259,0 WZS 40960 () 0 + 80 be,0,4 [kworker/20:1H] -0 [020] d.h1. 960.989476: block_rq_complete: 259,0 WZS () 0 + 80 be,0,4 [0] -0 [020] dNh1. 960.989482: block_io_done: 259,0 WZS 0 () 0 + 0 none,0,0 [swapper/20] Trace Event Breakdown: Event | Device | Op | Sector | Sectors | Byte Size | Calculation block_bio_queue | 259,0 | WZS | 0 | 80 | - | 80 × 512 = 40,960 block_getrq | 259,0 | WZS | 0 | 80 | - | 80 × 512 = 40,960 block_io_start | 259,0 | WZS | 0 | 80 | 40960 | Direct from trace block_rq_insert | 259,0 | WZS | 0 | 80 | 40960 | Direct from trace block_rq_issue | 259,0 | WZS | 0 | 80 | 40960 | Direct from trace block_rq_complete | 259,0 | WZS | 0 | 80 | - | 80 × 512 = 40,960 block_io_done | 259,0 | WZS | 0 | 0 | 0 | Completion (no data) Total Bytes Transferred: Sectors: 80 Bytes: 80 × 512 = 40,960 bytes Tested with ftrace blktrace on NVMe devices using blkdiscard with the -z (write-zeroes) flag. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

blktrace: trace zone write plugging operations

2025-10-22T17:14:05+00:00

Trace zone write plugging operations on block devices. As tracing of zoned block commands needs the upper 32bit of the widened 64bit action, only add traces to blktrace if user-space has requested version 2 of the blktrace protocol. Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Signed-off-by: Jens Axboe

blktrace: expose ZONE APPEND completions to blktrace

2025-10-22T17:14:05+00:00

Expose ZONE APPEND completions as a block trace completion action to blktrace. As tracing of zoned block commands needs the upper 32bit of the widened 64bit action, only add traces to blktrace if user-space has requested version 2 of the blktrace protocol. Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Signed-off-by: Jens Axboe

blktrace: add block trace commands for zone operations

2025-10-22T17:14:05+00:00

Add block trace commands for zone operations. These commands can only be handled with version 2 of the blktrace protocol. For version 1, warn if a command that does not fit into the 16 bits reserved for the command in this version is passed in. Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Reviewed-by: Damien Le Moal Signed-off-by: Jens Axboe

blktrace: add definitions for struct blk_io_trace2

2025-10-22T17:14:05+00:00

Add definitions for the extended version of the blktrace protocol using a wider action type to be able to record new actions in the kernel. Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Signed-off-by: Jens Axboe

blktrace: add definitions for blk_user_trace_setup2

2025-10-22T17:14:05+00:00

Add definitions for a version 2 of the blk_user_trace_setup ioctl. This new ioctl will enable a different struct layout of the binary data passed to user-space when using a new version of the blktrace utility requesting the new struct layout. Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn Signed-off-by: Jens Axboe

block: remove bounce buffering support

2025-05-05T19:22:39+00:00

The block layer bounce buffering support is unused now, remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: John Garry Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250505081138.3435992-7-hch@lst.de Signed-off-by: Jens Axboe

blktrace: fix comment in blktrace_api.h

2018-03-30T20:16:24+00:00

The `__u64 time` field of the blk_io_trace struct refers to the time in nanoseconds, not in microseconds. It is set in __blk_add_trace, which does the following: t->time = ktime_to_ns(ktime_get()); ktime_to_ns returns ktime_t in nanoseconds, not microseconds. Signed-off-by: Souvik Banerjee Signed-off-by: Jens Axboe

blktrace_api.h: fix comment for struct blk_user_trace_setup

2018-02-26T19:26:02+00:00

'struct blk_user_trace_setup' is passed to BLKTRACESETUP, not BLKTRACESTART. Signed-off-by: Eric Biggers Signed-off-by: Jens Axboe

License cleanup: add SPDX license identifier to uapi header files with no license

2017-11-02T10:19:54+00:00

Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman