blktrace: cleanup the __trace_note_message interface

Pass the cgroup_subsys_state instead of a the blkg so that blktrace
doesn't need to poke into blk-cgroup internals, and give the name a
blk prefix as the current name is way too generic for a public
interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220420042723.1010598-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index 978ef5d6fe6ab75d9b002b7209375b7f55a7eda7..b18d6c31c22518939d54f2dbf586bf581baa8bfc 100644 (file)
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -1102,13 +1102,13 @@ struct bfq_group *bfqq_group(struct bfq_queue *bfqq);
                break;                                                  \
        bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH);           \
        blk_add_cgroup_trace_msg((bfqd)->queue,                         \
-                       bfqg_to_blkg(bfqq_group(bfqq))->blkcg,          \
+                       &bfqg_to_blkg(bfqq_group(bfqq))->blkcg->css,    \
                        "%s " fmt, pid_str, ##args);                    \
 } while (0)
 
 #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {                    \
        blk_add_cgroup_trace_msg((bfqd)->queue,                         \
-               bfqg_to_blkg(bfqg)->blkcg, fmt, ##args);                \
+               &bfqg_to_blkg(bfqg)->blkcg->css, fmt, ##args);          \
 } while (0)
 
 #else /* CONFIG_BFQ_GROUP_IOSCHED */

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 469c483719bea8309a92a14a6c2c39cb9cc5bd15..447e1b8722f7a797449123bb7f5a7030ed244844 100644 (file)
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -227,7 +227,7 @@ static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw)
                break;                                                  \
        if ((__tg)) {                                                   \
                blk_add_cgroup_trace_msg(__td->queue,                   \
-                       tg_to_blkg(__tg)->blkcg, "throtl " fmt, ##args);\
+                       &tg_to_blkg(__tg)->blkcg->css, "throtl " fmt, ##args);\
        } else {                                                        \
                blk_add_trace_msg(__td->queue, "throtl " fmt, ##args);  \
        }                                                               \

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 22501a293fa545b4d744ed6dc054f133fc8e799b..623e22492afa50de750593485e0e264519c44779 100644 (file)
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -27,12 +27,10 @@ struct blk_trace {
        atomic_t dropped;
 };
 
-struct blkcg;
-
 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 extern void blk_trace_shutdown(struct request_queue *);
-extern __printf(3, 4)
-void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, const char *fmt, ...);
+__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
+               struct cgroup_subsys_state *css, const char *fmt, ...);
 
 /**
  * blk_add_trace_msg - Add a (simple) message to the blktrace stream
@@ -47,14 +45,14 @@ void __trace_note_message(struct blk_trace *, struct blkcg *blkcg, const char *f
  *     NOTE: Can not use 'static inline' due to presence of var args...
  *
  **/
-#define blk_add_cgroup_trace_msg(q, cg, fmt, ...)                      \
+#define blk_add_cgroup_trace_msg(q, css, fmt, ...)                     \
        do {                                                            \
                struct blk_trace *bt;                                   \
                                                                        \
                rcu_read_lock();                                        \
                bt = rcu_dereference((q)->blk_trace);                   \
                if (unlikely(bt))                                       \
-                       __trace_note_message(bt, cg, fmt, ##__VA_ARGS__);\
+                       __blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
                rcu_read_unlock();                                      \
        } while (0)
 #define blk_add_trace_msg(q, fmt, ...)                                 \

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 4d5629196d01dcb1592bb2ad483b56cdf8966f9d..9ef349ac49c0174d53dc41eb35872f5cc4f8bd08 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -145,13 +145,14 @@ static void trace_note_time(struct blk_trace *bt)
        local_irq_restore(flags);
 }
 
-void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
-       const char *fmt, ...)
+void __blk_trace_note_message(struct blk_trace *bt,
+               struct cgroup_subsys_state *css, const char *fmt, ...)
 {
        int n;
        va_list args;
        unsigned long flags;
        char *buf;
+       u64 cgid = 0;
 
        if (unlikely(bt->trace_state != Blktrace_running &&
                     !blk_tracer_enabled))
@@ -170,17 +171,16 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
        n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
        va_end(args);
 
-       if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
-               blkcg = NULL;
 #ifdef CONFIG_BLK_CGROUP
-       trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n,
-                  blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
-#else
-       trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, 0);
+       if (css && (blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
+               cgid = cgroup_id(css->cgroup);
+       else
+               cgid = 1;
 #endif
+       trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, cgid);
        local_irq_restore(flags);
 }
-EXPORT_SYMBOL_GPL(__trace_note_message);
+EXPORT_SYMBOL_GPL(__blk_trace_note_message);
 
 static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
                         pid_t pid)
@@ -411,7 +411,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
                return PTR_ERR(msg);
 
        bt = filp->private_data;
-       __trace_note_message(bt, NULL, "%s", msg);
+       __blk_trace_note_message(bt, NULL, "%s", msg);
        kfree(msg);
 
        return count;