3a366e614d
bio completion didn't kick block_bio_complete TP. Only dm was
explicitly triggering the TP on IO completion. This makes
block_bio_complete TP useless for tracers which want to know about
bios, and all other bio based drivers skip generating blktrace
completion events.
This patch makes all bio completions via bio_endio() generate
block_bio_complete TP.
* Explicit trace_block_bio_complete() invocation removed from dm and
the trace point is unexported.
* @rq dropped from trace_block_bio_complete(). bios may fly around
w/o queue associated. Verifying and accessing the assocaited queue
belongs to TP probes.
* blktrace now gets both request and bio completions. Make it ignore
bio completions if request completion path is happening.
This makes all bio based drivers generate blktrace completion events
properly and makes the block_bio_complete TP actually useful.
v2: With this change, block_bio_complete TP could be invoked on sg
commands which have bio's with %NULL bi_bdev. Update TP
assignment code to check whether bio->bi_bdev is %NULL before
dereferencing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Original-patch-by: Namhyung Kim <namhyung@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
116 lines
3.3 KiB
C
116 lines
3.3 KiB
C
#ifndef BLKTRACE_H
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#define BLKTRACE_H
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#include <linux/blkdev.h>
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#include <linux/relay.h>
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#include <linux/compat.h>
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#include <uapi/linux/blktrace_api.h>
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#if defined(CONFIG_BLK_DEV_IO_TRACE)
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#include <linux/sysfs.h>
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struct blk_trace {
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int trace_state;
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bool rq_based;
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struct rchan *rchan;
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unsigned long __percpu *sequence;
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unsigned char __percpu *msg_data;
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u16 act_mask;
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u64 start_lba;
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u64 end_lba;
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u32 pid;
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u32 dev;
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struct dentry *dir;
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struct dentry *dropped_file;
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struct dentry *msg_file;
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atomic_t dropped;
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};
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extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
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extern void blk_trace_shutdown(struct request_queue *);
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extern int do_blk_trace_setup(struct request_queue *q, char *name,
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dev_t dev, struct block_device *bdev,
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struct blk_user_trace_setup *buts);
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extern __printf(2, 3)
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void __trace_note_message(struct blk_trace *, const char *fmt, ...);
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/**
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* blk_add_trace_msg - Add a (simple) message to the blktrace stream
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* @q: queue the io is for
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* @fmt: format to print message in
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* args... Variable argument list for format
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*
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* Description:
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* Records a (simple) message onto the blktrace stream.
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*
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* NOTE: BLK_TN_MAX_MSG characters are output at most.
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* NOTE: Can not use 'static inline' due to presence of var args...
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*
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**/
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#define blk_add_trace_msg(q, fmt, ...) \
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do { \
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struct blk_trace *bt = (q)->blk_trace; \
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if (unlikely(bt)) \
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__trace_note_message(bt, fmt, ##__VA_ARGS__); \
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} while (0)
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#define BLK_TN_MAX_MSG 128
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extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
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void *data, size_t len);
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extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
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struct block_device *bdev,
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char __user *arg);
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extern int blk_trace_startstop(struct request_queue *q, int start);
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extern int blk_trace_remove(struct request_queue *q);
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extern void blk_trace_remove_sysfs(struct device *dev);
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extern int blk_trace_init_sysfs(struct device *dev);
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extern struct attribute_group blk_trace_attr_group;
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#else /* !CONFIG_BLK_DEV_IO_TRACE */
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# define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
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# define blk_trace_shutdown(q) do { } while (0)
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# define do_blk_trace_setup(q, name, dev, bdev, buts) (-ENOTTY)
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# define blk_add_driver_data(q, rq, data, len) do {} while (0)
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# define blk_trace_setup(q, name, dev, bdev, arg) (-ENOTTY)
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# define blk_trace_startstop(q, start) (-ENOTTY)
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# define blk_trace_remove(q) (-ENOTTY)
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# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
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# define blk_trace_remove_sysfs(dev) do { } while (0)
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static inline int blk_trace_init_sysfs(struct device *dev)
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{
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return 0;
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}
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#endif /* CONFIG_BLK_DEV_IO_TRACE */
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#ifdef CONFIG_COMPAT
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struct compat_blk_user_trace_setup {
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char name[32];
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u16 act_mask;
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u32 buf_size;
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u32 buf_nr;
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compat_u64 start_lba;
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compat_u64 end_lba;
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u32 pid;
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};
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#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
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#endif
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#if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
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static inline int blk_cmd_buf_len(struct request *rq)
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{
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return (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? rq->cmd_len * 3 : 1;
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}
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extern void blk_dump_cmd(char *buf, struct request *rq);
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extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
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#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
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#endif
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