Hi,
This patch-series is based on the initial patch posted by
Christoph Hellwig <[email protected]>. While debugging the driver and block
layer this print message is very meaningful. Also, we centralize the
REQ_OP_XXX to the string conversion in the blk-core.c so that other
dependent subsystems can use this helper without having to duplicate
the code e.g. f2fs, blk-mq-debugfs.c.
Please consider this for 5.3.
In case someone is interested please find the test log for print_err_req
with null_blk, f2fs tracing and blk-mq-debugfs->blk_mq_debugfs_rq_show()
at the end of this patch.
Regards,
Chaitanya
Changes since V2:-
1. Add a centralized definition of the REQ_OP_XXX string array in the
blk-core so that it will be available to other dependent subsystems
as well.
2. Adjust the code and use blk_op_str() in the blk-mq-debugfs.c
3. Adjust the code and use blk_op_str() in the f2fs tracing.
Chaitanya Kulkarni (5):
block: add centralize REQ_OP_XXX to string helper
block: use blk_op_str() in blk-mq-debugfs.c
block: update print_req_error()
f2fs: use block layer helper for REQ_OP_XXX
f2fs: get rid of duplicate code for in tracing
Christoph Hellwig (1):
block: improve print_req_error
block/blk-core.c | 55 ++++++++++++++++++++++++++++++++-----
block/blk-mq-debugfs.c | 24 +++-------------
include/linux/blkdev.h | 3 ++
include/trace/events/f2fs.h | 20 +++-----------
4 files changed, 59 insertions(+), 43 deletions(-)
A. Following is the sample error message with forced REQ_OP_WRITE,
REQ_OP_WRITE_ZEROES and REQ_OP_DISCARD failure from modified
null_blk for testing :-
------------------------------------------------------------------
[ 489.013530] blk_update_request: I/O error, dev nullb0, sector 0 op
0x1:(WRITE) flags 0x8800 phys_seg 1 prio class 0
[ 510.569833] blk_update_request: I/O error, dev nullb0, sector 0 op
0x9:(WRITE_ZEROES) flags 0x400800 phys_seg 0 prio class 0
[ 557.009194] blk_update_request: I/O error, dev nullb0, sector 0 op
0x3:(DISCARD) flags 0x800 phys_seg 1 prio class 0
B. F2FS Tracing with this patch-series :-
-----------------------------------------
# 1. Format and mount device with f2fs :-
linux-block (for-next) # mkfs.f2fs -f /dev/nvme0n1
F2FS-tools: mkfs.f2fs Ver: 1.12.0 (2018-11-12)
<snip>
Info: format successful
linux-block (for-next) # mount /dev/nvme0n1 /mnt/nvme0n1
# 2. Enable f2fs traces which are associated with the bio:-
linux-block (for-next) # cat
/sys/kernel/debug/tracing/events/f2fs/f2fs_prepare_read_bio/enable
1
linux-block (for-next) # cat
/sys/kernel/debug/tracing/events/f2fs/f2fs_prepare_write_bio/enable
1
linux-block (for-next) # cat
/sys/kernel/debug/tracing/events/f2fs/f2fs_submit_page_bio/enable
1
linux-block (for-next) # cat
/sys/kernel/debug/tracing/events/f2fs/f2fs_submit_read_bio/enable
1
linux-block (for-next) # cat
/sys/kernel/debug/tracing/events/f2fs/f2fs_submit_write_bio/enable
1
# 3. Issue I/O using dd(1) :-
linux-block (for-next) # dd of=/mnt/nvme0n1/data if=/dev/zero bs=4k count=100
100+0 records in
100+0 records out
409600 bytes (410 kB) copied, 0.00315802 s, 130 MB/s
linux-block (for-next) #
linux-block (for-next) #
# 4, Collect the trace
linux-block (for-next) # cat /sys/kernel/debug/tracing/trace_pipe
# 5. Following is the trimmed trace where we get rid of first few columns :-
f2fs_trace_pid: 103: 0 1af2 dd
f2fs_trace_ios: 103: 0 0 ---------------- 3 0 2000 1600 1
f2fs_trace_pid: 103: 0 1e8 kworker/u24:5
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), DATA, sector =
53256, size = 4096
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), DATA, sector =
53256, size = 4096
f2fs_trace_ios: 103: 0 1ace ---------------- 1 1 800 1a01 1
f2fs_trace_ios: 103: 0 1e8 ---------------- 2 1 800 1401 1
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), NODE, sector =
40968, size = 4096
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), NODE, sector =
40968, size = 4096
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), NODE, sector =
45056, size = 4096
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(S), NODE, sector =
45056, size = 4096
f2fs_trace_ios: 103: 0 1ace ---------------- 2 1 800 1600 1
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(S|M|P), META, sector
= 8192, size = 8192
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(S|M|P), META, sector =
8192, size = 8192
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(S|M|P|PF|FUA),
META_FLUSH, sector = 8208, size = 4096
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(S|M|P|PF|FUA),
META_FLUSH, sector = 8208, size = 4096
f2fs_trace_ios: 103: 0 1e8 ---------------- 3 1 3800 400 3
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(), DATA, sector =
53264, size = 40960
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(), DATA, sector =
53264, size = 40960
f2fs_trace_pid: 103: 0 1b16 dd
f2fs_trace_ios: 103: 0 1af2 ---------------- 0 1 100000 1a02 a
f2fs_prepare_write_bio: dev = (259,0)/(259,0), rw = WRITE(), DATA, sector =
1064960, size = 409600
f2fs_submit_write_bio: dev = (259,0)/(259,0), rw = WRITE(), DATA, sector =
1064960, size = 409600
C. blk-mq-debugfs.c tests for __blk_mq_debugfs_rq_show() :-
-----------------------------------------------------------
# 1. Issue write-zeroes, disacrd and write operation on the null_blk
with modified null_blk
@@ -1180,6 +1207,20 @@ static blk_status_t null_handle_cmd(struct nullb_cmd
*cmd)
}
}
+ /* just discard for write zeroes for now */
+ switch (req_op(cmd->rq)) {
+ case REQ_OP_DISCARD:
+ /* fall through */
+ case REQ_OP_WRITE_ZEROES:
+ mdelay(10000);
+ break;
+ case REQ_OP_WRITE:
+ mdelay(10000);
+ }
+
linux-block (for-next) # blkdiscard -z -o 0 -l 40960 /dev/nullb0
linux-block (for-next) # blkdiscard -o 0 -l 40960 /dev/nullb0
linux-block (for-next) # dd if=/dev/zero of=/dev/nullb0 bs=4k count=1
oflag=direct
#2. Read the hctx busy file every second, each type of request should
be block for 10 seconds and must appear in the hctx->busy file in
the debugfs. This will lead to from block/blk-mq-debugfs.c :
{"busy", 0400, hctx_busy_show}
hctx_show_busy_rq()
__blk_mq_debugfs_rq_show()
blk_op_str()
linux-block (for-next) # while [ 1 ]; do cat
/sys/kernel/debug/block/nullb0/hctx0/busy ; sleep 1; done
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000095104d0a {.op=WRITE_ZEROES, .cmd_flags=SYNC|NOUNMAP,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=48,
.internal_tag=96}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000051de04b0 {.op=DISCARD, .cmd_flags=SYNC,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=47}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
0000000037e18909 {.op=WRITE, .cmd_flags=SYNC|IDLE,
.rq_flags=STARTED|ELVPRIV|IO_STAT|STATS, .state=in_flight, .tag=49,
.internal_tag=97}
--
2.19.1
