| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Mikulas Patocka | 6355 | 99.23% | 8 | 42.11% |
| Mark Rutland | 24 | 0.37% | 1 | 5.26% |
| Mike Snitzer | 11 | 0.17% | 3 | 15.79% |
| Michael Christie | 7 | 0.11% | 1 | 5.26% |
| Kees Cook | 2 | 0.03% | 1 | 5.26% |
| Michal Hocko | 1 | 0.02% | 1 | 5.26% |
| Christoph Lameter | 1 | 0.02% | 1 | 5.26% |
| Pekka J Enberg | 1 | 0.02% | 1 | 5.26% |
| Arun K S | 1 | 0.02% | 1 | 5.26% |
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 5.26% |
| Total | 6404 | 19 |
// SPDX-License-Identifier: GPL-2.0 #include <linux/errno.h> #include <linux/numa.h> #include <linux/slab.h> #include <linux/rculist.h> #include <linux/threads.h> #include <linux/preempt.h> #include <linux/irqflags.h> #include <linux/vmalloc.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/device-mapper.h> #include "dm-core.h" #include "dm-stats.h" #define DM_MSG_PREFIX "stats" static int dm_stat_need_rcu_barrier; /* * Using 64-bit values to avoid overflow (which is a * problem that block/genhd.c's IO accounting has). */ struct dm_stat_percpu { unsigned long long sectors[2]; unsigned long long ios[2]; unsigned long long merges[2]; unsigned long long ticks[2]; unsigned long long io_ticks[2]; unsigned long long io_ticks_total; unsigned long long time_in_queue; unsigned long long *histogram; }; struct dm_stat_shared { atomic_t in_flight[2]; unsigned long long stamp; struct dm_stat_percpu tmp; }; struct dm_stat { struct list_head list_entry; int id; unsigned stat_flags; size_t n_entries; sector_t start; sector_t end; sector_t step; unsigned n_histogram_entries; unsigned long long *histogram_boundaries; const char *program_id; const char *aux_data; struct rcu_head rcu_head; size_t shared_alloc_size; size_t percpu_alloc_size; size_t histogram_alloc_size; struct dm_stat_percpu *stat_percpu[NR_CPUS]; struct dm_stat_shared stat_shared[0]; }; #define STAT_PRECISE_TIMESTAMPS 1 struct dm_stats_last_position { sector_t last_sector; unsigned last_rw; }; /* * A typo on the command line could possibly make the kernel run out of memory * and crash. To prevent the crash we account all used memory. We fail if we * exhaust 1/4 of all memory or 1/2 of vmalloc space. */ #define DM_STATS_MEMORY_FACTOR 4 #define DM_STATS_VMALLOC_FACTOR 2 static DEFINE_SPINLOCK(shared_memory_lock); static unsigned long shared_memory_amount; static bool __check_shared_memory(size_t alloc_size) { size_t a; a = shared_memory_amount + alloc_size; if (a < shared_memory_amount) return false; if (a >> PAGE_SHIFT > totalram_pages() / DM_STATS_MEMORY_FACTOR) return false; #ifdef CONFIG_MMU if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR) return false; #endif return true; } static bool check_shared_memory(size_t alloc_size) { bool ret; spin_lock_irq(&shared_memory_lock); ret = __check_shared_memory(alloc_size); spin_unlock_irq(&shared_memory_lock); return ret; } static bool claim_shared_memory(size_t alloc_size) { spin_lock_irq(&shared_memory_lock); if (!__check_shared_memory(alloc_size)) { spin_unlock_irq(&shared_memory_lock); return false; } shared_memory_amount += alloc_size; spin_unlock_irq(&shared_memory_lock); return true; } static void free_shared_memory(size_t alloc_size) { unsigned long flags; spin_lock_irqsave(&shared_memory_lock, flags); if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) { spin_unlock_irqrestore(&shared_memory_lock, flags); DMCRIT("Memory usage accounting bug."); return; } shared_memory_amount -= alloc_size; spin_unlock_irqrestore(&shared_memory_lock, flags); } static void *dm_kvzalloc(size_t alloc_size, int node) { void *p; if (!claim_shared_memory(alloc_size)) return NULL; p = kvzalloc_node(alloc_size, GFP_KERNEL | __GFP_NOMEMALLOC, node); if (p) return p; free_shared_memory(alloc_size); return NULL; } static void dm_kvfree(void *ptr, size_t alloc_size) { if (!ptr) return; free_shared_memory(alloc_size); kvfree(ptr); } static void dm_stat_free(struct rcu_head *head) { int cpu; struct dm_stat *s = container_of(head, struct dm_stat, rcu_head); kfree(s->histogram_boundaries); kfree(s->program_id); kfree(s->aux_data); for_each_possible_cpu(cpu) { dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size); dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size); } dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size); dm_kvfree(s, s->shared_alloc_size); } static int dm_stat_in_flight(struct dm_stat_shared *shared) { return atomic_read(&shared->in_flight[READ]) + atomic_read(&shared->in_flight[WRITE]); } void dm_stats_init(struct dm_stats *stats) { int cpu; struct dm_stats_last_position *last; mutex_init(&stats->mutex); INIT_LIST_HEAD(&stats->list); stats->last = alloc_percpu(struct dm_stats_last_position); for_each_possible_cpu(cpu) { last = per_cpu_ptr(stats->last, cpu); last->last_sector = (sector_t)ULLONG_MAX; last->last_rw = UINT_MAX; } } void dm_stats_cleanup(struct dm_stats *stats) { size_t ni; struct dm_stat *s; struct dm_stat_shared *shared; while (!list_empty(&stats->list)) { s = container_of(stats->list.next, struct dm_stat, list_entry); list_del(&s->list_entry); for (ni = 0; ni < s->n_entries; ni++) { shared = &s->stat_shared[ni]; if (WARN_ON(dm_stat_in_flight(shared))) { DMCRIT("leaked in-flight counter at index %lu " "(start %llu, end %llu, step %llu): reads %d, writes %d", (unsigned long)ni, (unsigned long long)s->start, (unsigned long long)s->end, (unsigned long long)s->step, atomic_read(&shared->in_flight[READ]), atomic_read(&shared->in_flight[WRITE])); } } dm_stat_free(&s->rcu_head); } free_percpu(stats->last); mutex_destroy(&stats->mutex); } static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, sector_t step, unsigned stat_flags, unsigned n_histogram_entries, unsigned long long *histogram_boundaries, const char *program_id, const char *aux_data, void (*suspend_callback)(struct mapped_device *), void (*resume_callback)(struct mapped_device *), struct mapped_device *md) { struct list_head *l; struct dm_stat *s, *tmp_s; sector_t n_entries; size_t ni; size_t shared_alloc_size; size_t percpu_alloc_size; size_t histogram_alloc_size; struct dm_stat_percpu *p; int cpu; int ret_id; int r; if (end < start || !step) return -EINVAL; n_entries = end - start; if (dm_sector_div64(n_entries, step)) n_entries++; if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1)) return -EOVERFLOW; shared_alloc_size = sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared); if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries) return -EOVERFLOW; percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu); if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries) return -EOVERFLOW; histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long); if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long)) return -EOVERFLOW; if (!check_shared_memory(shared_alloc_size + histogram_alloc_size + num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size))) return -ENOMEM; s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE); if (!s) return -ENOMEM; s->stat_flags = stat_flags; s->n_entries = n_entries; s->start = start; s->end = end; s->step = step; s->shared_alloc_size = shared_alloc_size; s->percpu_alloc_size = percpu_alloc_size; s->histogram_alloc_size = histogram_alloc_size; s->n_histogram_entries = n_histogram_entries; s->histogram_boundaries = kmemdup(histogram_boundaries, s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL); if (!s->histogram_boundaries) { r = -ENOMEM; goto out; } s->program_id = kstrdup(program_id, GFP_KERNEL); if (!s->program_id) { r = -ENOMEM; goto out; } s->aux_data = kstrdup(aux_data, GFP_KERNEL); if (!s->aux_data) { r = -ENOMEM; goto out; } for (ni = 0; ni < n_entries; ni++) { atomic_set(&s->stat_shared[ni].in_flight[READ], 0); atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0); } if (s->n_histogram_entries) { unsigned long long *hi; hi = dm_kvzalloc(s->histogram_alloc_size, NUMA_NO_NODE); if (!hi) { r = -ENOMEM; goto out; } for (ni = 0; ni < n_entries; ni++) { s->stat_shared[ni].tmp.histogram = hi; hi += s->n_histogram_entries + 1; } } for_each_possible_cpu(cpu) { p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu)); if (!p) { r = -ENOMEM; goto out; } s->stat_percpu[cpu] = p; if (s->n_histogram_entries) { unsigned long long *hi; hi = dm_kvzalloc(s->histogram_alloc_size, cpu_to_node(cpu)); if (!hi) { r = -ENOMEM; goto out; } for (ni = 0; ni < n_entries; ni++) { p[ni].histogram = hi; hi += s->n_histogram_entries + 1; } } } /* * Suspend/resume to make sure there is no i/o in flight, * so that newly created statistics will be exact. * * (note: we couldn't suspend earlier because we must not * allocate memory while suspended) */ suspend_callback(md); mutex_lock(&stats->mutex); s->id = 0; list_for_each(l, &stats->list) { tmp_s = container_of(l, struct dm_stat, list_entry); if (WARN_ON(tmp_s->id < s->id)) { r = -EINVAL; goto out_unlock_resume; } if (tmp_s->id > s->id) break; if (unlikely(s->id == INT_MAX)) { r = -ENFILE; goto out_unlock_resume; } s->id++; } ret_id = s->id; list_add_tail_rcu(&s->list_entry, l); mutex_unlock(&stats->mutex); resume_callback(md); return ret_id; out_unlock_resume: mutex_unlock(&stats->mutex); resume_callback(md); out: dm_stat_free(&s->rcu_head); return r; } static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id) { struct dm_stat *s; list_for_each_entry(s, &stats->list, list_entry) { if (s->id > id) break; if (s->id == id) return s; } return NULL; } static int dm_stats_delete(struct dm_stats *stats, int id) { struct dm_stat *s; int cpu; mutex_lock(&stats->mutex); s = __dm_stats_find(stats, id); if (!s) { mutex_unlock(&stats->mutex); return -ENOENT; } list_del_rcu(&s->list_entry); mutex_unlock(&stats->mutex); /* * vfree can't be called from RCU callback */ for_each_possible_cpu(cpu) if (is_vmalloc_addr(s->stat_percpu) || is_vmalloc_addr(s->stat_percpu[cpu][0].histogram)) goto do_sync_free; if (is_vmalloc_addr(s) || is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) { do_sync_free: synchronize_rcu_expedited(); dm_stat_free(&s->rcu_head); } else { WRITE_ONCE(dm_stat_need_rcu_barrier, 1); call_rcu(&s->rcu_head, dm_stat_free); } return 0; } static int dm_stats_list(struct dm_stats *stats, const char *program, char *result, unsigned maxlen) { struct dm_stat *s; sector_t len; unsigned sz = 0; /* * Output format: * <region_id>: <start_sector>+<length> <step> <program_id> <aux_data> */ mutex_lock(&stats->mutex); list_for_each_entry(s, &stats->list, list_entry) { if (!program || !strcmp(program, s->program_id)) { len = s->end - s->start; DMEMIT("%d: %llu+%llu %llu %s %s", s->id, (unsigned long long)s->start, (unsigned long long)len, (unsigned long long)s->step, s->program_id, s->aux_data); if (s->stat_flags & STAT_PRECISE_TIMESTAMPS) DMEMIT(" precise_timestamps"); if (s->n_histogram_entries) { unsigned i; DMEMIT(" histogram:"); for (i = 0; i < s->n_histogram_entries; i++) { if (i) DMEMIT(","); DMEMIT("%llu", s->histogram_boundaries[i]); } } DMEMIT("\n"); } } mutex_unlock(&stats->mutex); return 1; } static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared, struct dm_stat_percpu *p) { /* * This is racy, but so is part_round_stats_single. */ unsigned long long now, difference; unsigned in_flight_read, in_flight_write; if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS))) now = jiffies; else now = ktime_to_ns(ktime_get()); difference = now - shared->stamp; if (!difference) return; in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]); in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]); if (in_flight_read) p->io_ticks[READ] += difference; if (in_flight_write) p->io_ticks[WRITE] += difference; if (in_flight_read + in_flight_write) { p->io_ticks_total += difference; p->time_in_queue += (in_flight_read + in_flight_write) * difference; } shared->stamp = now; } static void dm_stat_for_entry(struct dm_stat *s, size_t entry, int idx, sector_t len, struct dm_stats_aux *stats_aux, bool end, unsigned long duration_jiffies) { struct dm_stat_shared *shared = &s->stat_shared[entry]; struct dm_stat_percpu *p; /* * For strict correctness we should use local_irq_save/restore * instead of preempt_disable/enable. * * preempt_disable/enable is racy if the driver finishes bios * from non-interrupt context as well as from interrupt context * or from more different interrupts. * * On 64-bit architectures the race only results in not counting some * events, so it is acceptable. On 32-bit architectures the race could * cause the counter going off by 2^32, so we need to do proper locking * there. * * part_stat_lock()/part_stat_unlock() have this race too. */ #if BITS_PER_LONG == 32 unsigned long flags; local_irq_save(flags); #else preempt_disable(); #endif p = &s->stat_percpu[smp_processor_id()][entry]; if (!end) { dm_stat_round(s, shared, p); atomic_inc(&shared->in_flight[idx]); } else { unsigned long long duration; dm_stat_round(s, shared, p); atomic_dec(&shared->in_flight[idx]); p->sectors[idx] += len; p->ios[idx] += 1; p->merges[idx] += stats_aux->merged; if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) { p->ticks[idx] += duration_jiffies; duration = jiffies_to_msecs(duration_jiffies); } else { p->ticks[idx] += stats_aux->duration_ns; duration = stats_aux->duration_ns; } if (s->n_histogram_entries) { unsigned lo = 0, hi = s->n_histogram_entries + 1; while (lo + 1 < hi) { unsigned mid = (lo + hi) / 2; if (s->histogram_boundaries[mid - 1] > duration) { hi = mid; } else { lo = mid; } } p->histogram[lo]++; } } #if BITS_PER_LONG == 32 local_irq_restore(flags); #else preempt_enable(); #endif } static void __dm_stat_bio(struct dm_stat *s, int bi_rw, sector_t bi_sector, sector_t end_sector, bool end, unsigned long duration_jiffies, struct dm_stats_aux *stats_aux) { sector_t rel_sector, offset, todo, fragment_len; size_t entry; if (end_sector <= s->start || bi_sector >= s->end) return; if (unlikely(bi_sector < s->start)) { rel_sector = 0; todo = end_sector - s->start; } else { rel_sector = bi_sector - s->start; todo = end_sector - bi_sector; } if (unlikely(end_sector > s->end)) todo -= (end_sector - s->end); offset = dm_sector_div64(rel_sector, s->step); entry = rel_sector; do { if (WARN_ON_ONCE(entry >= s->n_entries)) { DMCRIT("Invalid area access in region id %d", s->id); return; } fragment_len = todo; if (fragment_len > s->step - offset) fragment_len = s->step - offset; dm_stat_for_entry(s, entry, bi_rw, fragment_len, stats_aux, end, duration_jiffies); todo -= fragment_len; entry++; offset = 0; } while (unlikely(todo != 0)); } void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw, sector_t bi_sector, unsigned bi_sectors, bool end, unsigned long duration_jiffies, struct dm_stats_aux *stats_aux) { struct dm_stat *s; sector_t end_sector; struct dm_stats_last_position *last; bool got_precise_time; if (unlikely(!bi_sectors)) return; end_sector = bi_sector + bi_sectors; if (!end) { /* * A race condition can at worst result in the merged flag being * misrepresented, so we don't have to disable preemption here. */ last = raw_cpu_ptr(stats->last); stats_aux->merged = (bi_sector == (READ_ONCE(last->last_sector) && ((bi_rw == WRITE) == (READ_ONCE(last->last_rw) == WRITE)) )); WRITE_ONCE(last->last_sector, end_sector); WRITE_ONCE(last->last_rw, bi_rw); } rcu_read_lock(); got_precise_time = false; list_for_each_entry_rcu(s, &stats->list, list_entry) { if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) { if (!end) stats_aux->duration_ns = ktime_to_ns(ktime_get()); else stats_aux->duration_ns = ktime_to_ns(ktime_get()) - stats_aux->duration_ns; got_precise_time = true; } __dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux); } rcu_read_unlock(); } static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared, struct dm_stat *s, size_t x) { int cpu; struct dm_stat_percpu *p; local_irq_disable(); p = &s->stat_percpu[smp_processor_id()][x]; dm_stat_round(s, shared, p); local_irq_enable(); shared->tmp.sectors[READ] = 0; shared->tmp.sectors[WRITE] = 0; shared->tmp.ios[READ] = 0; shared->tmp.ios[WRITE] = 0; shared->tmp.merges[READ] = 0; shared->tmp.merges[WRITE] = 0; shared->tmp.ticks[READ] = 0; shared->tmp.ticks[WRITE] = 0; shared->tmp.io_ticks[READ] = 0; shared->tmp.io_ticks[WRITE] = 0; shared->tmp.io_ticks_total = 0; shared->tmp.time_in_queue = 0; if (s->n_histogram_entries) memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long)); for_each_possible_cpu(cpu) { p = &s->stat_percpu[cpu][x]; shared->tmp.sectors[READ] += READ_ONCE(p->sectors[READ]); shared->tmp.sectors[WRITE] += READ_ONCE(p->sectors[WRITE]); shared->tmp.ios[READ] += READ_ONCE(p->ios[READ]); shared->tmp.ios[WRITE] += READ_ONCE(p->ios[WRITE]); shared->tmp.merges[READ] += READ_ONCE(p->merges[READ]); shared->tmp.merges[WRITE] += READ_ONCE(p->merges[WRITE]); shared->tmp.ticks[READ] += READ_ONCE(p->ticks[READ]); shared->tmp.ticks[WRITE] += READ_ONCE(p->ticks[WRITE]); shared->tmp.io_ticks[READ] += READ_ONCE(p->io_ticks[READ]); shared->tmp.io_ticks[WRITE] += READ_ONCE(p->io_ticks[WRITE]); shared->tmp.io_ticks_total += READ_ONCE(p->io_ticks_total); shared->tmp.time_in_queue += READ_ONCE(p->time_in_queue); if (s->n_histogram_entries) { unsigned i; for (i = 0; i < s->n_histogram_entries + 1; i++) shared->tmp.histogram[i] += READ_ONCE(p->histogram[i]); } } } static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end, bool init_tmp_percpu_totals) { size_t x; struct dm_stat_shared *shared; struct dm_stat_percpu *p; for (x = idx_start; x < idx_end; x++) { shared = &s->stat_shared[x]; if (init_tmp_percpu_totals) __dm_stat_init_temporary_percpu_totals(shared, s, x); local_irq_disable(); p = &s->stat_percpu[smp_processor_id()][x]; p->sectors[READ] -= shared->tmp.sectors[READ]; p->sectors[WRITE] -= shared->tmp.sectors[WRITE]; p->ios[READ] -= shared->tmp.ios[READ]; p->ios[WRITE] -= shared->tmp.ios[WRITE]; p->merges[READ] -= shared->tmp.merges[READ]; p->merges[WRITE] -= shared->tmp.merges[WRITE]; p->ticks[READ] -= shared->tmp.ticks[READ]; p->ticks[WRITE] -= shared->tmp.ticks[WRITE]; p->io_ticks[READ] -= shared->tmp.io_ticks[READ]; p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE]; p->io_ticks_total -= shared->tmp.io_ticks_total; p->time_in_queue -= shared->tmp.time_in_queue; local_irq_enable(); if (s->n_histogram_entries) { unsigned i; for (i = 0; i < s->n_histogram_entries + 1; i++) { local_irq_disable(); p = &s->stat_percpu[smp_processor_id()][x]; p->histogram[i] -= shared->tmp.histogram[i]; local_irq_enable(); } } } } static int dm_stats_clear(struct dm_stats *stats, int id) { struct dm_stat *s; mutex_lock(&stats->mutex); s = __dm_stats_find(stats, id); if (!s) { mutex_unlock(&stats->mutex); return -ENOENT; } __dm_stat_clear(s, 0, s->n_entries, true); mutex_unlock(&stats->mutex); return 1; } /* * This is like jiffies_to_msec, but works for 64-bit values. */ static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j) { unsigned long long result; unsigned mult; if (s->stat_flags & STAT_PRECISE_TIMESTAMPS) return j; result = 0; if (j) result = jiffies_to_msecs(j & 0x3fffff); if (j >= 1 << 22) { mult = jiffies_to_msecs(1 << 22); result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff); } if (j >= 1ULL << 44) result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44); return result; } static int dm_stats_print(struct dm_stats *stats, int id, size_t idx_start, size_t idx_len, bool clear, char *result, unsigned maxlen) { unsigned sz = 0; struct dm_stat *s; size_t x; sector_t start, end, step; size_t idx_end; struct dm_stat_shared *shared; /* * Output format: * <start_sector>+<length> counters */ mutex_lock(&stats->mutex); s = __dm_stats_find(stats, id); if (!s) { mutex_unlock(&stats->mutex); return -ENOENT; } idx_end = idx_start + idx_len; if (idx_end < idx_start || idx_end > s->n_entries) idx_end = s->n_entries; if (idx_start > idx_end) idx_start = idx_end; step = s->step; start = s->start + (step * idx_start); for (x = idx_start; x < idx_end; x++, start = end) { shared = &s->stat_shared[x]; end = start + step; if (unlikely(end > s->end)) end = s->end; __dm_stat_init_temporary_percpu_totals(shared, s, x); DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu", (unsigned long long)start, (unsigned long long)step, shared->tmp.ios[READ], shared->tmp.merges[READ], shared->tmp.sectors[READ], dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]), shared->tmp.ios[WRITE], shared->tmp.merges[WRITE], shared->tmp.sectors[WRITE], dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]), dm_stat_in_flight(shared), dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total), dm_jiffies_to_msec64(s, shared->tmp.time_in_queue), dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]), dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE])); if (s->n_histogram_entries) { unsigned i; for (i = 0; i < s->n_histogram_entries + 1; i++) { DMEMIT("%s%llu", !i ? " " : ":", shared->tmp.histogram[i]); } } DMEMIT("\n"); if (unlikely(sz + 1 >= maxlen)) goto buffer_overflow; } if (clear) __dm_stat_clear(s, idx_start, idx_end, false); buffer_overflow: mutex_unlock(&stats->mutex); return 1; } static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data) { struct dm_stat *s; const char *new_aux_data; mutex_lock(&stats->mutex); s = __dm_stats_find(stats, id); if (!s) { mutex_unlock(&stats->mutex); return -ENOENT; } new_aux_data = kstrdup(aux_data, GFP_KERNEL); if (!new_aux_data) { mutex_unlock(&stats->mutex); return -ENOMEM; } kfree(s->aux_data); s->aux_data = new_aux_data; mutex_unlock(&stats->mutex); return 0; } static int parse_histogram(const char *h, unsigned *n_histogram_entries, unsigned long long **histogram_boundaries) { const char *q; unsigned n; unsigned long long last; *n_histogram_entries = 1; for (q = h; *q; q++) if (*q == ',') (*n_histogram_entries)++; *histogram_boundaries = kmalloc_array(*n_histogram_entries, sizeof(unsigned long long), GFP_KERNEL); if (!*histogram_boundaries) return -ENOMEM; n = 0; last = 0; while (1) { unsigned long long hi; int s; char ch; s = sscanf(h, "%llu%c", &hi, &ch); if (!s || (s == 2 && ch != ',')) return -EINVAL; if (hi <= last) return -EINVAL; last = hi; (*histogram_boundaries)[n] = hi; if (s == 1) return 0; h = strchr(h, ',') + 1; n++; } } static int message_stats_create(struct mapped_device *md, unsigned argc, char **argv, char *result, unsigned maxlen) { int r; int id; char dummy; unsigned long long start, end, len, step; unsigned divisor; const char *program_id, *aux_data; unsigned stat_flags = 0; unsigned n_histogram_entries = 0; unsigned long long *histogram_boundaries = NULL; struct dm_arg_set as, as_backup; const char *a; unsigned feature_args; /* * Input format: * <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]] */ if (argc < 3) goto ret_einval; as.argc = argc; as.argv = argv; dm_consume_args(&as, 1); a = dm_shift_arg(&as); if (!strcmp(a, "-")) { start = 0; len = dm_get_size(md); if (!len) len = 1; } else if (sscanf(a, "%llu+%llu%c", &start, &len, &dummy) != 2 || start != (sector_t)start || len != (sector_t)len) goto ret_einval; end = start + len; if (start >= end) goto ret_einval; a = dm_shift_arg(&as); if (sscanf(a, "/%u%c", &divisor, &dummy) == 1) { if (!divisor) return -EINVAL; step = end - start; if (do_div(step, divisor)) step++; if (!step) step = 1; } else if (sscanf(a, "%llu%c", &step, &dummy) != 1 || step != (sector_t)step || !step) goto ret_einval; as_backup = as; a = dm_shift_arg(&as); if (a && sscanf(a, "%u%c", &feature_args, &dummy) == 1) { while (feature_args--) { a = dm_shift_arg(&as); if (!a) goto ret_einval; if (!strcasecmp(a, "precise_timestamps")) stat_flags |= STAT_PRECISE_TIMESTAMPS; else if (!strncasecmp(a, "histogram:", 10)) { if (n_histogram_entries) goto ret_einval; if ((r = parse_histogram(a + 10, &n_histogram_entries, &histogram_boundaries))) goto ret; } else goto ret_einval; } } else { as = as_backup; } program_id = "-"; aux_data = "-"; a = dm_shift_arg(&as); if (a) program_id = a; a = dm_shift_arg(&as); if (a) aux_data = a; if (as.argc) goto ret_einval; /* * If a buffer overflow happens after we created the region, * it's too late (the userspace would retry with a larger * buffer, but the region id that caused the overflow is already * leaked). So we must detect buffer overflow in advance. */ snprintf(result, maxlen, "%d", INT_MAX); if (dm_message_test_buffer_overflow(result, maxlen)) { r = 1; goto ret; } id = dm_stats_create(dm_get_stats(md), start, end, step, stat_flags, n_histogram_entries, histogram_boundaries, program_id, aux_data, dm_internal_suspend_fast, dm_internal_resume_fast, md); if (id < 0) { r = id; goto ret; } snprintf(result, maxlen, "%d", id); r = 1; goto ret; ret_einval: r = -EINVAL; ret: kfree(histogram_boundaries); return r; } static int message_stats_delete(struct mapped_device *md, unsigned argc, char **argv) { int id; char dummy; if (argc != 2) return -EINVAL; if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) return -EINVAL; return dm_stats_delete(dm_get_stats(md), id); } static int message_stats_clear(struct mapped_device *md, unsigned argc, char **argv) { int id; char dummy; if (argc != 2) return -EINVAL; if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) return -EINVAL; return dm_stats_clear(dm_get_stats(md), id); } static int message_stats_list(struct mapped_device *md, unsigned argc, char **argv, char *result, unsigned maxlen) { int r; const char *program = NULL; if (argc < 1 || argc > 2) return -EINVAL; if (argc > 1) { program = kstrdup(argv[1], GFP_KERNEL); if (!program) return -ENOMEM; } r = dm_stats_list(dm_get_stats(md), program, result, maxlen); kfree(program); return r; } static int message_stats_print(struct mapped_device *md, unsigned argc, char **argv, bool clear, char *result, unsigned maxlen) { int id; char dummy; unsigned long idx_start = 0, idx_len = ULONG_MAX; if (argc != 2 && argc != 4) return -EINVAL; if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) return -EINVAL; if (argc > 3) { if (strcmp(argv[2], "-") && sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1) return -EINVAL; if (strcmp(argv[3], "-") && sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1) return -EINVAL; } return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear, result, maxlen); } static int message_stats_set_aux(struct mapped_device *md, unsigned argc, char **argv) { int id; char dummy; if (argc != 3) return -EINVAL; if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0) return -EINVAL; return dm_stats_set_aux(dm_get_stats(md), id, argv[2]); } int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv, char *result, unsigned maxlen) { int r; /* All messages here must start with '@' */ if (!strcasecmp(argv[0], "@stats_create")) r = message_stats_create(md, argc, argv, result, maxlen); else if (!strcasecmp(argv[0], "@stats_delete")) r = message_stats_delete(md, argc, argv); else if (!strcasecmp(argv[0], "@stats_clear")) r = message_stats_clear(md, argc, argv); else if (!strcasecmp(argv[0], "@stats_list")) r = message_stats_list(md, argc, argv, result, maxlen); else if (!strcasecmp(argv[0], "@stats_print")) r = message_stats_print(md, argc, argv, false, result, maxlen); else if (!strcasecmp(argv[0], "@stats_print_clear")) r = message_stats_print(md, argc, argv, true, result, maxlen); else if (!strcasecmp(argv[0], "@stats_set_aux")) r = message_stats_set_aux(md, argc, argv); else return 2; /* this wasn't a stats message */ if (r == -EINVAL) DMWARN("Invalid parameters for message %s", argv[0]); return r; } int __init dm_statistics_init(void) { shared_memory_amount = 0; dm_stat_need_rcu_barrier = 0; return 0; } void dm_statistics_exit(void) { if (dm_stat_need_rcu_barrier) rcu_barrier(); if (WARN_ON(shared_memory_amount)) DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount); } module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, S_IRUGO); MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");
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