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1209 lines
29 KiB
1209 lines
29 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/errno.h> |
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#include <linux/numa.h> |
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#include <linux/slab.h> |
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#include <linux/rculist.h> |
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#include <linux/threads.h> |
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#include <linux/preempt.h> |
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#include <linux/irqflags.h> |
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#include <linux/vmalloc.h> |
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#include <linux/mm.h> |
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#include <linux/module.h> |
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#include <linux/device-mapper.h> |
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|
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#include "dm-core.h" |
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#include "dm-stats.h" |
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|
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#define DM_MSG_PREFIX "stats" |
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|
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static int dm_stat_need_rcu_barrier; |
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|
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/* |
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* Using 64-bit values to avoid overflow (which is a |
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* problem that block/genhd.c's IO accounting has). |
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*/ |
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struct dm_stat_percpu { |
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unsigned long long sectors[2]; |
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unsigned long long ios[2]; |
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unsigned long long merges[2]; |
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unsigned long long ticks[2]; |
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unsigned long long io_ticks[2]; |
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unsigned long long io_ticks_total; |
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unsigned long long time_in_queue; |
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unsigned long long *histogram; |
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}; |
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|
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struct dm_stat_shared { |
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atomic_t in_flight[2]; |
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unsigned long long stamp; |
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struct dm_stat_percpu tmp; |
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}; |
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|
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struct dm_stat { |
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struct list_head list_entry; |
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int id; |
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unsigned stat_flags; |
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size_t n_entries; |
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sector_t start; |
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sector_t end; |
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sector_t step; |
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unsigned n_histogram_entries; |
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unsigned long long *histogram_boundaries; |
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const char *program_id; |
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const char *aux_data; |
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struct rcu_head rcu_head; |
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size_t shared_alloc_size; |
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size_t percpu_alloc_size; |
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size_t histogram_alloc_size; |
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struct dm_stat_percpu *stat_percpu[NR_CPUS]; |
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struct dm_stat_shared stat_shared[]; |
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}; |
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|
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#define STAT_PRECISE_TIMESTAMPS 1 |
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|
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struct dm_stats_last_position { |
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sector_t last_sector; |
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unsigned last_rw; |
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}; |
|
|
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/* |
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* A typo on the command line could possibly make the kernel run out of memory |
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* and crash. To prevent the crash we account all used memory. We fail if we |
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* exhaust 1/4 of all memory or 1/2 of vmalloc space. |
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*/ |
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#define DM_STATS_MEMORY_FACTOR 4 |
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#define DM_STATS_VMALLOC_FACTOR 2 |
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|
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static DEFINE_SPINLOCK(shared_memory_lock); |
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|
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static unsigned long shared_memory_amount; |
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|
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static bool __check_shared_memory(size_t alloc_size) |
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{ |
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size_t a; |
|
|
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a = shared_memory_amount + alloc_size; |
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if (a < shared_memory_amount) |
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return false; |
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if (a >> PAGE_SHIFT > totalram_pages() / DM_STATS_MEMORY_FACTOR) |
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return false; |
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#ifdef CONFIG_MMU |
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if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR) |
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return false; |
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#endif |
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return true; |
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} |
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|
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static bool check_shared_memory(size_t alloc_size) |
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{ |
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bool ret; |
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|
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spin_lock_irq(&shared_memory_lock); |
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|
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ret = __check_shared_memory(alloc_size); |
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|
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spin_unlock_irq(&shared_memory_lock); |
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|
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return ret; |
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} |
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|
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static bool claim_shared_memory(size_t alloc_size) |
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{ |
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spin_lock_irq(&shared_memory_lock); |
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|
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if (!__check_shared_memory(alloc_size)) { |
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spin_unlock_irq(&shared_memory_lock); |
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return false; |
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} |
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|
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shared_memory_amount += alloc_size; |
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|
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spin_unlock_irq(&shared_memory_lock); |
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|
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return true; |
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} |
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|
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static void free_shared_memory(size_t alloc_size) |
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{ |
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unsigned long flags; |
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|
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spin_lock_irqsave(&shared_memory_lock, flags); |
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|
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if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) { |
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spin_unlock_irqrestore(&shared_memory_lock, flags); |
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DMCRIT("Memory usage accounting bug."); |
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return; |
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} |
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|
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shared_memory_amount -= alloc_size; |
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|
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spin_unlock_irqrestore(&shared_memory_lock, flags); |
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} |
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|
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static void *dm_kvzalloc(size_t alloc_size, int node) |
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{ |
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void *p; |
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|
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if (!claim_shared_memory(alloc_size)) |
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return NULL; |
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|
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p = kvzalloc_node(alloc_size, GFP_KERNEL | __GFP_NOMEMALLOC, node); |
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if (p) |
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return p; |
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|
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free_shared_memory(alloc_size); |
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|
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return NULL; |
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} |
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|
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static void dm_kvfree(void *ptr, size_t alloc_size) |
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{ |
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if (!ptr) |
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return; |
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|
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free_shared_memory(alloc_size); |
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|
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kvfree(ptr); |
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} |
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|
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static void dm_stat_free(struct rcu_head *head) |
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{ |
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int cpu; |
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struct dm_stat *s = container_of(head, struct dm_stat, rcu_head); |
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|
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kfree(s->histogram_boundaries); |
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kfree(s->program_id); |
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kfree(s->aux_data); |
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for_each_possible_cpu(cpu) { |
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dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size); |
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dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size); |
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} |
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dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size); |
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dm_kvfree(s, s->shared_alloc_size); |
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} |
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|
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static int dm_stat_in_flight(struct dm_stat_shared *shared) |
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{ |
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return atomic_read(&shared->in_flight[READ]) + |
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atomic_read(&shared->in_flight[WRITE]); |
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} |
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|
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void dm_stats_init(struct dm_stats *stats) |
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{ |
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int cpu; |
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struct dm_stats_last_position *last; |
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|
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mutex_init(&stats->mutex); |
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INIT_LIST_HEAD(&stats->list); |
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stats->last = alloc_percpu(struct dm_stats_last_position); |
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for_each_possible_cpu(cpu) { |
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last = per_cpu_ptr(stats->last, cpu); |
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last->last_sector = (sector_t)ULLONG_MAX; |
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last->last_rw = UINT_MAX; |
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} |
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} |
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|
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void dm_stats_cleanup(struct dm_stats *stats) |
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{ |
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size_t ni; |
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struct dm_stat *s; |
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struct dm_stat_shared *shared; |
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|
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while (!list_empty(&stats->list)) { |
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s = container_of(stats->list.next, struct dm_stat, list_entry); |
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list_del(&s->list_entry); |
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for (ni = 0; ni < s->n_entries; ni++) { |
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shared = &s->stat_shared[ni]; |
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if (WARN_ON(dm_stat_in_flight(shared))) { |
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DMCRIT("leaked in-flight counter at index %lu " |
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"(start %llu, end %llu, step %llu): reads %d, writes %d", |
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(unsigned long)ni, |
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(unsigned long long)s->start, |
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(unsigned long long)s->end, |
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(unsigned long long)s->step, |
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atomic_read(&shared->in_flight[READ]), |
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atomic_read(&shared->in_flight[WRITE])); |
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} |
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} |
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dm_stat_free(&s->rcu_head); |
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} |
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free_percpu(stats->last); |
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mutex_destroy(&stats->mutex); |
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} |
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|
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static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, |
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sector_t step, unsigned stat_flags, |
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unsigned n_histogram_entries, |
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unsigned long long *histogram_boundaries, |
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const char *program_id, const char *aux_data, |
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void (*suspend_callback)(struct mapped_device *), |
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void (*resume_callback)(struct mapped_device *), |
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struct mapped_device *md) |
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{ |
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struct list_head *l; |
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struct dm_stat *s, *tmp_s; |
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sector_t n_entries; |
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size_t ni; |
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size_t shared_alloc_size; |
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size_t percpu_alloc_size; |
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size_t histogram_alloc_size; |
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struct dm_stat_percpu *p; |
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int cpu; |
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int ret_id; |
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int r; |
|
|
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if (end < start || !step) |
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return -EINVAL; |
|
|
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n_entries = end - start; |
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if (dm_sector_div64(n_entries, step)) |
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n_entries++; |
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|
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if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1)) |
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return -EOVERFLOW; |
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|
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shared_alloc_size = struct_size(s, stat_shared, n_entries); |
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if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries) |
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return -EOVERFLOW; |
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|
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percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu); |
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if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries) |
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return -EOVERFLOW; |
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|
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histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long); |
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if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long)) |
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return -EOVERFLOW; |
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|
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if (!check_shared_memory(shared_alloc_size + histogram_alloc_size + |
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num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size))) |
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return -ENOMEM; |
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|
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s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE); |
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if (!s) |
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return -ENOMEM; |
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|
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s->stat_flags = stat_flags; |
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s->n_entries = n_entries; |
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s->start = start; |
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s->end = end; |
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s->step = step; |
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s->shared_alloc_size = shared_alloc_size; |
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s->percpu_alloc_size = percpu_alloc_size; |
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s->histogram_alloc_size = histogram_alloc_size; |
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|
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s->n_histogram_entries = n_histogram_entries; |
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s->histogram_boundaries = kmemdup(histogram_boundaries, |
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s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL); |
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if (!s->histogram_boundaries) { |
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r = -ENOMEM; |
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goto out; |
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} |
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|
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s->program_id = kstrdup(program_id, GFP_KERNEL); |
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if (!s->program_id) { |
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r = -ENOMEM; |
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goto out; |
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} |
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s->aux_data = kstrdup(aux_data, GFP_KERNEL); |
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if (!s->aux_data) { |
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r = -ENOMEM; |
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goto out; |
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} |
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|
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for (ni = 0; ni < n_entries; ni++) { |
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atomic_set(&s->stat_shared[ni].in_flight[READ], 0); |
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atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0); |
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} |
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|
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if (s->n_histogram_entries) { |
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unsigned long long *hi; |
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hi = dm_kvzalloc(s->histogram_alloc_size, NUMA_NO_NODE); |
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if (!hi) { |
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r = -ENOMEM; |
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goto out; |
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} |
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for (ni = 0; ni < n_entries; ni++) { |
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s->stat_shared[ni].tmp.histogram = hi; |
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hi += s->n_histogram_entries + 1; |
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} |
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} |
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|
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for_each_possible_cpu(cpu) { |
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p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu)); |
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if (!p) { |
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r = -ENOMEM; |
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goto out; |
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} |
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s->stat_percpu[cpu] = p; |
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if (s->n_histogram_entries) { |
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unsigned long long *hi; |
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hi = dm_kvzalloc(s->histogram_alloc_size, cpu_to_node(cpu)); |
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if (!hi) { |
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r = -ENOMEM; |
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goto out; |
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} |
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for (ni = 0; ni < n_entries; ni++) { |
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p[ni].histogram = hi; |
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hi += s->n_histogram_entries + 1; |
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} |
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} |
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} |
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|
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/* |
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* Suspend/resume to make sure there is no i/o in flight, |
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* so that newly created statistics will be exact. |
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* |
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* (note: we couldn't suspend earlier because we must not |
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* allocate memory while suspended) |
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*/ |
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suspend_callback(md); |
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|
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mutex_lock(&stats->mutex); |
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s->id = 0; |
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list_for_each(l, &stats->list) { |
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tmp_s = container_of(l, struct dm_stat, list_entry); |
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if (WARN_ON(tmp_s->id < s->id)) { |
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r = -EINVAL; |
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goto out_unlock_resume; |
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} |
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if (tmp_s->id > s->id) |
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break; |
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if (unlikely(s->id == INT_MAX)) { |
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r = -ENFILE; |
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goto out_unlock_resume; |
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} |
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s->id++; |
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} |
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ret_id = s->id; |
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list_add_tail_rcu(&s->list_entry, l); |
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mutex_unlock(&stats->mutex); |
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|
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resume_callback(md); |
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|
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return ret_id; |
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|
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out_unlock_resume: |
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mutex_unlock(&stats->mutex); |
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resume_callback(md); |
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out: |
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dm_stat_free(&s->rcu_head); |
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return r; |
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} |
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|
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static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id) |
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{ |
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struct dm_stat *s; |
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|
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list_for_each_entry(s, &stats->list, list_entry) { |
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if (s->id > id) |
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break; |
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if (s->id == id) |
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return s; |
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} |
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|
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return NULL; |
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} |
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|
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static int dm_stats_delete(struct dm_stats *stats, int id) |
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{ |
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struct dm_stat *s; |
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int cpu; |
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|
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mutex_lock(&stats->mutex); |
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|
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s = __dm_stats_find(stats, id); |
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if (!s) { |
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mutex_unlock(&stats->mutex); |
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return -ENOENT; |
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} |
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|
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list_del_rcu(&s->list_entry); |
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mutex_unlock(&stats->mutex); |
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|
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/* |
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* vfree can't be called from RCU callback |
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*/ |
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for_each_possible_cpu(cpu) |
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if (is_vmalloc_addr(s->stat_percpu) || |
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is_vmalloc_addr(s->stat_percpu[cpu][0].histogram)) |
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goto do_sync_free; |
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if (is_vmalloc_addr(s) || |
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is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) { |
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do_sync_free: |
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synchronize_rcu_expedited(); |
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dm_stat_free(&s->rcu_head); |
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} else { |
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WRITE_ONCE(dm_stat_need_rcu_barrier, 1); |
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call_rcu(&s->rcu_head, dm_stat_free); |
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} |
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return 0; |
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} |
|
|
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static int dm_stats_list(struct dm_stats *stats, const char *program, |
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char *result, unsigned maxlen) |
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{ |
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struct dm_stat *s; |
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sector_t len; |
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unsigned sz = 0; |
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|
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/* |
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* Output format: |
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* <region_id>: <start_sector>+<length> <step> <program_id> <aux_data> |
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*/ |
|
|
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mutex_lock(&stats->mutex); |
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list_for_each_entry(s, &stats->list, list_entry) { |
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if (!program || !strcmp(program, s->program_id)) { |
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len = s->end - s->start; |
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DMEMIT("%d: %llu+%llu %llu %s %s", s->id, |
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(unsigned long long)s->start, |
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(unsigned long long)len, |
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(unsigned long long)s->step, |
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s->program_id, |
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s->aux_data); |
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if (s->stat_flags & STAT_PRECISE_TIMESTAMPS) |
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DMEMIT(" precise_timestamps"); |
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if (s->n_histogram_entries) { |
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unsigned i; |
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DMEMIT(" histogram:"); |
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for (i = 0; i < s->n_histogram_entries; i++) { |
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if (i) |
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DMEMIT(","); |
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DMEMIT("%llu", s->histogram_boundaries[i]); |
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} |
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} |
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DMEMIT("\n"); |
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} |
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} |
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mutex_unlock(&stats->mutex); |
|
|
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return 1; |
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} |
|
|
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static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared, |
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struct dm_stat_percpu *p) |
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{ |
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/* |
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* This is racy, but so is part_round_stats_single. |
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*/ |
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unsigned long long now, difference; |
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unsigned in_flight_read, in_flight_write; |
|
|
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if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS))) |
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now = jiffies; |
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else |
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now = ktime_to_ns(ktime_get()); |
|
|
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difference = now - shared->stamp; |
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if (!difference) |
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return; |
|
|
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in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]); |
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in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]); |
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if (in_flight_read) |
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p->io_ticks[READ] += difference; |
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if (in_flight_write) |
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p->io_ticks[WRITE] += difference; |
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if (in_flight_read + in_flight_write) { |
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p->io_ticks_total += difference; |
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p->time_in_queue += (in_flight_read + in_flight_write) * difference; |
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} |
|
shared->stamp = now; |
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} |
|
|
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static void dm_stat_for_entry(struct dm_stat *s, size_t entry, |
|
int idx, sector_t len, |
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struct dm_stats_aux *stats_aux, bool end, |
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unsigned long duration_jiffies) |
|
{ |
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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. |
|
* |
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* 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. |
|
* |
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* On 64-bit architectures the race only results in not counting some |
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* 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. |
|
* |
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* part_stat_lock()/part_stat_unlock() have this race too. |
|
*/ |
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#if BITS_PER_LONG == 32 |
|
unsigned long flags; |
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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]); |
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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");
|
|
|