From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/md/bcache/sysfs.c | 1183 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1183 insertions(+) create mode 100644 drivers/md/bcache/sysfs.c (limited to 'drivers/md/bcache/sysfs.c') diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c new file mode 100644 index 000000000..cfac56caa --- /dev/null +++ b/drivers/md/bcache/sysfs.c @@ -0,0 +1,1183 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * bcache sysfs interfaces + * + * Copyright 2010, 2011 Kent Overstreet + * Copyright 2012 Google, Inc. + */ + +#include "bcache.h" +#include "sysfs.h" +#include "btree.h" +#include "request.h" +#include "writeback.h" +#include "features.h" + +#include +#include +#include + +extern bool bcache_is_reboot; + +/* Default is 0 ("writethrough") */ +static const char * const bch_cache_modes[] = { + "writethrough", + "writeback", + "writearound", + "none", + NULL +}; + +static const char * const bch_reada_cache_policies[] = { + "all", + "meta-only", + NULL +}; + +/* Default is 0 ("auto") */ +static const char * const bch_stop_on_failure_modes[] = { + "auto", + "always", + NULL +}; + +static const char * const cache_replacement_policies[] = { + "lru", + "fifo", + "random", + NULL +}; + +static const char * const error_actions[] = { + "unregister", + "panic", + NULL +}; + +write_attribute(attach); +write_attribute(detach); +write_attribute(unregister); +write_attribute(stop); +write_attribute(clear_stats); +write_attribute(trigger_gc); +write_attribute(prune_cache); +write_attribute(flash_vol_create); + +read_attribute(bucket_size); +read_attribute(block_size); +read_attribute(nbuckets); +read_attribute(tree_depth); +read_attribute(root_usage_percent); +read_attribute(priority_stats); +read_attribute(btree_cache_size); +read_attribute(btree_cache_max_chain); +read_attribute(cache_available_percent); +read_attribute(written); +read_attribute(btree_written); +read_attribute(metadata_written); +read_attribute(active_journal_entries); +read_attribute(backing_dev_name); +read_attribute(backing_dev_uuid); + +sysfs_time_stats_attribute(btree_gc, sec, ms); +sysfs_time_stats_attribute(btree_split, sec, us); +sysfs_time_stats_attribute(btree_sort, ms, us); +sysfs_time_stats_attribute(btree_read, ms, us); + +read_attribute(btree_nodes); +read_attribute(btree_used_percent); +read_attribute(average_key_size); +read_attribute(dirty_data); +read_attribute(bset_tree_stats); +read_attribute(feature_compat); +read_attribute(feature_ro_compat); +read_attribute(feature_incompat); + +read_attribute(state); +read_attribute(cache_read_races); +read_attribute(reclaim); +read_attribute(reclaimed_journal_buckets); +read_attribute(flush_write); +read_attribute(writeback_keys_done); +read_attribute(writeback_keys_failed); +read_attribute(io_errors); +read_attribute(congested); +read_attribute(cutoff_writeback); +read_attribute(cutoff_writeback_sync); +rw_attribute(congested_read_threshold_us); +rw_attribute(congested_write_threshold_us); + +rw_attribute(sequential_cutoff); +rw_attribute(data_csum); +rw_attribute(cache_mode); +rw_attribute(readahead_cache_policy); +rw_attribute(stop_when_cache_set_failed); +rw_attribute(writeback_metadata); +rw_attribute(writeback_running); +rw_attribute(writeback_percent); +rw_attribute(writeback_delay); +rw_attribute(writeback_rate); +rw_attribute(writeback_consider_fragment); + +rw_attribute(writeback_rate_update_seconds); +rw_attribute(writeback_rate_i_term_inverse); +rw_attribute(writeback_rate_p_term_inverse); +rw_attribute(writeback_rate_fp_term_low); +rw_attribute(writeback_rate_fp_term_mid); +rw_attribute(writeback_rate_fp_term_high); +rw_attribute(writeback_rate_minimum); +read_attribute(writeback_rate_debug); + +read_attribute(stripe_size); +read_attribute(partial_stripes_expensive); + +rw_attribute(synchronous); +rw_attribute(journal_delay_ms); +rw_attribute(io_disable); +rw_attribute(running); +rw_attribute(label); +rw_attribute(errors); +rw_attribute(io_error_limit); +rw_attribute(io_error_halflife); +rw_attribute(verify); +rw_attribute(bypass_torture_test); +rw_attribute(key_merging_disabled); +rw_attribute(gc_always_rewrite); +rw_attribute(expensive_debug_checks); +rw_attribute(cache_replacement_policy); +rw_attribute(btree_shrinker_disabled); +rw_attribute(copy_gc_enabled); +rw_attribute(idle_max_writeback_rate); +rw_attribute(gc_after_writeback); +rw_attribute(size); + +static ssize_t bch_snprint_string_list(char *buf, + size_t size, + const char * const list[], + size_t selected) +{ + char *out = buf; + size_t i; + + for (i = 0; list[i]; i++) + out += scnprintf(out, buf + size - out, + i == selected ? "[%s] " : "%s ", list[i]); + + out[-1] = '\n'; + return out - buf; +} + +SHOW(__bch_cached_dev) +{ + struct cached_dev *dc = container_of(kobj, struct cached_dev, + disk.kobj); + char const *states[] = { "no cache", "clean", "dirty", "inconsistent" }; + int wb = dc->writeback_running; + +#define var(stat) (dc->stat) + + if (attr == &sysfs_cache_mode) + return bch_snprint_string_list(buf, PAGE_SIZE, + bch_cache_modes, + BDEV_CACHE_MODE(&dc->sb)); + + if (attr == &sysfs_readahead_cache_policy) + return bch_snprint_string_list(buf, PAGE_SIZE, + bch_reada_cache_policies, + dc->cache_readahead_policy); + + if (attr == &sysfs_stop_when_cache_set_failed) + return bch_snprint_string_list(buf, PAGE_SIZE, + bch_stop_on_failure_modes, + dc->stop_when_cache_set_failed); + + + sysfs_printf(data_csum, "%i", dc->disk.data_csum); + var_printf(verify, "%i"); + var_printf(bypass_torture_test, "%i"); + var_printf(writeback_metadata, "%i"); + var_printf(writeback_running, "%i"); + var_printf(writeback_consider_fragment, "%i"); + var_print(writeback_delay); + var_print(writeback_percent); + sysfs_hprint(writeback_rate, + wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0); + sysfs_printf(io_errors, "%i", atomic_read(&dc->io_errors)); + sysfs_printf(io_error_limit, "%i", dc->error_limit); + sysfs_printf(io_disable, "%i", dc->io_disable); + var_print(writeback_rate_update_seconds); + var_print(writeback_rate_i_term_inverse); + var_print(writeback_rate_p_term_inverse); + var_print(writeback_rate_fp_term_low); + var_print(writeback_rate_fp_term_mid); + var_print(writeback_rate_fp_term_high); + var_print(writeback_rate_minimum); + + if (attr == &sysfs_writeback_rate_debug) { + char rate[20]; + char dirty[20]; + char target[20]; + char proportional[20]; + char integral[20]; + char change[20]; + s64 next_io; + + /* + * Except for dirty and target, other values should + * be 0 if writeback is not running. + */ + bch_hprint(rate, + wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 + : 0); + bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9); + bch_hprint(target, dc->writeback_rate_target << 9); + bch_hprint(proportional, + wb ? dc->writeback_rate_proportional << 9 : 0); + bch_hprint(integral, + wb ? dc->writeback_rate_integral_scaled << 9 : 0); + bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0); + next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(), + NSEC_PER_MSEC) : 0; + + return sprintf(buf, + "rate:\t\t%s/sec\n" + "dirty:\t\t%s\n" + "target:\t\t%s\n" + "proportional:\t%s\n" + "integral:\t%s\n" + "change:\t\t%s/sec\n" + "next io:\t%llims\n", + rate, dirty, target, proportional, + integral, change, next_io); + } + + sysfs_hprint(dirty_data, + bcache_dev_sectors_dirty(&dc->disk) << 9); + + sysfs_hprint(stripe_size, ((uint64_t)dc->disk.stripe_size) << 9); + var_printf(partial_stripes_expensive, "%u"); + + var_hprint(sequential_cutoff); + + sysfs_print(running, atomic_read(&dc->running)); + sysfs_print(state, states[BDEV_STATE(&dc->sb)]); + + if (attr == &sysfs_label) { + memcpy(buf, dc->sb.label, SB_LABEL_SIZE); + buf[SB_LABEL_SIZE + 1] = '\0'; + strcat(buf, "\n"); + return strlen(buf); + } + + if (attr == &sysfs_backing_dev_name) { + snprintf(buf, BDEVNAME_SIZE + 1, "%pg", dc->bdev); + strcat(buf, "\n"); + return strlen(buf); + } + + if (attr == &sysfs_backing_dev_uuid) { + /* convert binary uuid into 36-byte string plus '\0' */ + snprintf(buf, 36+1, "%pU", dc->sb.uuid); + strcat(buf, "\n"); + return strlen(buf); + } + +#undef var + return 0; +} +SHOW_LOCKED(bch_cached_dev) + +STORE(__cached_dev) +{ + struct cached_dev *dc = container_of(kobj, struct cached_dev, + disk.kobj); + ssize_t v; + struct cache_set *c; + struct kobj_uevent_env *env; + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + +#define d_strtoul(var) sysfs_strtoul(var, dc->var) +#define d_strtoul_nonzero(var) sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX) +#define d_strtoi_h(var) sysfs_hatoi(var, dc->var) + + sysfs_strtoul(data_csum, dc->disk.data_csum); + d_strtoul(verify); + sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test); + sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata); + sysfs_strtoul_bool(writeback_running, dc->writeback_running); + sysfs_strtoul_bool(writeback_consider_fragment, dc->writeback_consider_fragment); + sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX); + + sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, + 0, bch_cutoff_writeback); + + if (attr == &sysfs_writeback_rate) { + ssize_t ret; + long int v = atomic_long_read(&dc->writeback_rate.rate); + + ret = strtoul_safe_clamp(buf, v, 1, INT_MAX); + + if (!ret) { + atomic_long_set(&dc->writeback_rate.rate, v); + ret = size; + } + + return ret; + } + + sysfs_strtoul_clamp(writeback_rate_update_seconds, + dc->writeback_rate_update_seconds, + 1, WRITEBACK_RATE_UPDATE_SECS_MAX); + sysfs_strtoul_clamp(writeback_rate_i_term_inverse, + dc->writeback_rate_i_term_inverse, + 1, UINT_MAX); + sysfs_strtoul_clamp(writeback_rate_p_term_inverse, + dc->writeback_rate_p_term_inverse, + 1, UINT_MAX); + sysfs_strtoul_clamp(writeback_rate_fp_term_low, + dc->writeback_rate_fp_term_low, + 1, dc->writeback_rate_fp_term_mid - 1); + sysfs_strtoul_clamp(writeback_rate_fp_term_mid, + dc->writeback_rate_fp_term_mid, + dc->writeback_rate_fp_term_low + 1, + dc->writeback_rate_fp_term_high - 1); + sysfs_strtoul_clamp(writeback_rate_fp_term_high, + dc->writeback_rate_fp_term_high, + dc->writeback_rate_fp_term_mid + 1, UINT_MAX); + sysfs_strtoul_clamp(writeback_rate_minimum, + dc->writeback_rate_minimum, + 1, UINT_MAX); + + sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX); + + if (attr == &sysfs_io_disable) { + int v = strtoul_or_return(buf); + + dc->io_disable = v ? 1 : 0; + } + + sysfs_strtoul_clamp(sequential_cutoff, + dc->sequential_cutoff, + 0, UINT_MAX); + + if (attr == &sysfs_clear_stats) + bch_cache_accounting_clear(&dc->accounting); + + if (attr == &sysfs_running && + strtoul_or_return(buf)) { + v = bch_cached_dev_run(dc); + if (v) + return v; + } + + if (attr == &sysfs_cache_mode) { + v = __sysfs_match_string(bch_cache_modes, -1, buf); + if (v < 0) + return v; + + if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) { + SET_BDEV_CACHE_MODE(&dc->sb, v); + bch_write_bdev_super(dc, NULL); + } + } + + if (attr == &sysfs_readahead_cache_policy) { + v = __sysfs_match_string(bch_reada_cache_policies, -1, buf); + if (v < 0) + return v; + + if ((unsigned int) v != dc->cache_readahead_policy) + dc->cache_readahead_policy = v; + } + + if (attr == &sysfs_stop_when_cache_set_failed) { + v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf); + if (v < 0) + return v; + + dc->stop_when_cache_set_failed = v; + } + + if (attr == &sysfs_label) { + if (size > SB_LABEL_SIZE) + return -EINVAL; + memcpy(dc->sb.label, buf, size); + if (size < SB_LABEL_SIZE) + dc->sb.label[size] = '\0'; + if (size && dc->sb.label[size - 1] == '\n') + dc->sb.label[size - 1] = '\0'; + bch_write_bdev_super(dc, NULL); + if (dc->disk.c) { + memcpy(dc->disk.c->uuids[dc->disk.id].label, + buf, SB_LABEL_SIZE); + bch_uuid_write(dc->disk.c); + } + env = kzalloc_obj(struct kobj_uevent_env); + if (!env) + return -ENOMEM; + add_uevent_var(env, "DRIVER=bcache"); + add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid); + add_uevent_var(env, "CACHED_LABEL=%s", buf); + kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj, + KOBJ_CHANGE, + env->envp); + kfree(env); + } + + if (attr == &sysfs_attach) { + uint8_t set_uuid[16]; + + if (bch_parse_uuid(buf, set_uuid) < 16) + return -EINVAL; + + v = -ENOENT; + list_for_each_entry(c, &bch_cache_sets, list) { + v = bch_cached_dev_attach(dc, c, set_uuid); + if (!v) + return size; + } + if (v == -ENOENT) + pr_err("Can't attach %s: cache set not found\n", buf); + return v; + } + + if (attr == &sysfs_detach && dc->disk.c) + bch_cached_dev_detach(dc); + + if (attr == &sysfs_stop) + bcache_device_stop(&dc->disk); + + return size; +} + +STORE(bch_cached_dev) +{ + struct cached_dev *dc = container_of(kobj, struct cached_dev, + disk.kobj); + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + + mutex_lock(&bch_register_lock); + size = __cached_dev_store(kobj, attr, buf, size); + + if (attr == &sysfs_writeback_running) { + /* dc->writeback_running changed in __cached_dev_store() */ + if (IS_ERR_OR_NULL(dc->writeback_thread)) { + /* + * reject setting it to 1 via sysfs if writeback + * kthread is not created yet. + */ + if (dc->writeback_running) { + dc->writeback_running = false; + pr_err("%s: failed to run non-existent writeback thread\n", + dc->disk.disk->disk_name); + } + } else + /* + * writeback kthread will check if dc->writeback_running + * is true or false. + */ + bch_writeback_queue(dc); + } + + /* + * Only set BCACHE_DEV_WB_RUNNING when cached device attached to + * a cache set, otherwise it doesn't make sense. + */ + if (attr == &sysfs_writeback_percent) + if ((dc->disk.c != NULL) && + (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))) + schedule_delayed_work(&dc->writeback_rate_update, + dc->writeback_rate_update_seconds * HZ); + + mutex_unlock(&bch_register_lock); + return size; +} + +static struct attribute *bch_cached_dev_attrs[] = { + &sysfs_attach, + &sysfs_detach, + &sysfs_stop, +#if 0 + &sysfs_data_csum, +#endif + &sysfs_cache_mode, + &sysfs_readahead_cache_policy, + &sysfs_stop_when_cache_set_failed, + &sysfs_writeback_metadata, + &sysfs_writeback_running, + &sysfs_writeback_delay, + &sysfs_writeback_percent, + &sysfs_writeback_rate, + &sysfs_writeback_consider_fragment, + &sysfs_writeback_rate_update_seconds, + &sysfs_writeback_rate_i_term_inverse, + &sysfs_writeback_rate_p_term_inverse, + &sysfs_writeback_rate_fp_term_low, + &sysfs_writeback_rate_fp_term_mid, + &sysfs_writeback_rate_fp_term_high, + &sysfs_writeback_rate_minimum, + &sysfs_writeback_rate_debug, + &sysfs_io_errors, + &sysfs_io_error_limit, + &sysfs_io_disable, + &sysfs_dirty_data, + &sysfs_stripe_size, + &sysfs_partial_stripes_expensive, + &sysfs_sequential_cutoff, + &sysfs_clear_stats, + &sysfs_running, + &sysfs_state, + &sysfs_label, +#ifdef CONFIG_BCACHE_DEBUG + &sysfs_verify, + &sysfs_bypass_torture_test, +#endif + &sysfs_backing_dev_name, + &sysfs_backing_dev_uuid, + NULL +}; +ATTRIBUTE_GROUPS(bch_cached_dev); +KTYPE(bch_cached_dev); + +SHOW(bch_flash_dev) +{ + struct bcache_device *d = container_of(kobj, struct bcache_device, + kobj); + struct uuid_entry *u = &d->c->uuids[d->id]; + + sysfs_printf(data_csum, "%i", d->data_csum); + sysfs_hprint(size, u->sectors << 9); + + if (attr == &sysfs_label) { + memcpy(buf, u->label, SB_LABEL_SIZE); + buf[SB_LABEL_SIZE + 1] = '\0'; + strcat(buf, "\n"); + return strlen(buf); + } + + return 0; +} + +STORE(__bch_flash_dev) +{ + struct bcache_device *d = container_of(kobj, struct bcache_device, + kobj); + struct uuid_entry *u = &d->c->uuids[d->id]; + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + + sysfs_strtoul(data_csum, d->data_csum); + + if (attr == &sysfs_size) { + uint64_t v; + + strtoi_h_or_return(buf, v); + + u->sectors = v >> 9; + bch_uuid_write(d->c); + set_capacity(d->disk, u->sectors); + } + + if (attr == &sysfs_label) { + memcpy(u->label, buf, SB_LABEL_SIZE); + bch_uuid_write(d->c); + } + + if (attr == &sysfs_unregister) { + set_bit(BCACHE_DEV_DETACHING, &d->flags); + bcache_device_stop(d); + } + + return size; +} +STORE_LOCKED(bch_flash_dev) + +static struct attribute *bch_flash_dev_attrs[] = { + &sysfs_unregister, +#if 0 + &sysfs_data_csum, +#endif + &sysfs_label, + &sysfs_size, + NULL +}; +ATTRIBUTE_GROUPS(bch_flash_dev); +KTYPE(bch_flash_dev); + +struct bset_stats_op { + struct btree_op op; + size_t nodes; + struct bset_stats stats; +}; + +static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b) +{ + struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op); + + op->nodes++; + bch_btree_keys_stats(&b->keys, &op->stats); + + return MAP_CONTINUE; +} + +static int bch_bset_print_stats(struct cache_set *c, char *buf) +{ + struct bset_stats_op op; + int ret; + + memset(&op, 0, sizeof(op)); + bch_btree_op_init(&op.op, -1); + + ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE, + "btree nodes: %zu\n" + "written sets: %zu\n" + "unwritten sets: %zu\n" + "written key bytes: %zu\n" + "unwritten key bytes: %zu\n" + "floats: %zu\n" + "failed: %zu\n", + op.nodes, + op.stats.sets_written, op.stats.sets_unwritten, + op.stats.bytes_written, op.stats.bytes_unwritten, + op.stats.floats, op.stats.failed); +} + +static unsigned int bch_root_usage(struct cache_set *c) +{ + unsigned int bytes = 0; + struct bkey *k; + struct btree *b; + struct btree_iter_stack iter; + + goto lock_root; + + do { + rw_unlock(false, b); +lock_root: + b = c->root; + rw_lock(false, b, b->level); + } while (b != c->root); + + for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad) + bytes += bkey_bytes(k); + + rw_unlock(false, b); + + return (bytes * 100) / btree_bytes(c); +} + +static size_t bch_cache_size(struct cache_set *c) +{ + size_t ret = 0; + struct btree *b; + + mutex_lock(&c->bucket_lock); + list_for_each_entry(b, &c->btree_cache, list) + ret += 1 << (b->keys.page_order + PAGE_SHIFT); + + mutex_unlock(&c->bucket_lock); + return ret; +} + +static unsigned int bch_cache_max_chain(struct cache_set *c) +{ + unsigned int ret = 0; + struct hlist_head *h; + + mutex_lock(&c->bucket_lock); + + for (h = c->bucket_hash; + h < c->bucket_hash + (1 << BUCKET_HASH_BITS); + h++) { + ret = max(ret, hlist_count_nodes(h)); + } + + mutex_unlock(&c->bucket_lock); + return ret; +} + +static unsigned int bch_btree_used(struct cache_set *c) +{ + return div64_u64(c->gc_stats.key_bytes * 100, + (c->gc_stats.nodes ?: 1) * btree_bytes(c)); +} + +static unsigned int bch_average_key_size(struct cache_set *c) +{ + return c->gc_stats.nkeys + ? div64_u64(c->gc_stats.data, c->gc_stats.nkeys) + : 0; +} + +SHOW(__bch_cache_set) +{ + struct cache_set *c = container_of(kobj, struct cache_set, kobj); + + sysfs_print(synchronous, CACHE_SYNC(&c->cache->sb)); + sysfs_print(journal_delay_ms, c->journal_delay_ms); + sysfs_hprint(bucket_size, bucket_bytes(c->cache)); + sysfs_hprint(block_size, block_bytes(c->cache)); + sysfs_print(tree_depth, c->root->level); + sysfs_print(root_usage_percent, bch_root_usage(c)); + + sysfs_hprint(btree_cache_size, bch_cache_size(c)); + sysfs_print(btree_cache_max_chain, bch_cache_max_chain(c)); + sysfs_print(cache_available_percent, 100 - c->gc_stats.in_use); + + sysfs_print_time_stats(&c->btree_gc_time, btree_gc, sec, ms); + sysfs_print_time_stats(&c->btree_split_time, btree_split, sec, us); + sysfs_print_time_stats(&c->sort.time, btree_sort, ms, us); + sysfs_print_time_stats(&c->btree_read_time, btree_read, ms, us); + + sysfs_print(btree_used_percent, bch_btree_used(c)); + sysfs_print(btree_nodes, c->gc_stats.nodes); + sysfs_hprint(average_key_size, bch_average_key_size(c)); + + sysfs_print(cache_read_races, + atomic_long_read(&c->cache_read_races)); + + sysfs_print(reclaim, + atomic_long_read(&c->reclaim)); + + sysfs_print(reclaimed_journal_buckets, + atomic_long_read(&c->reclaimed_journal_buckets)); + + sysfs_print(flush_write, + atomic_long_read(&c->flush_write)); + + sysfs_print(writeback_keys_done, + atomic_long_read(&c->writeback_keys_done)); + sysfs_print(writeback_keys_failed, + atomic_long_read(&c->writeback_keys_failed)); + + if (attr == &sysfs_errors) + return bch_snprint_string_list(buf, PAGE_SIZE, error_actions, + c->on_error); + + /* See count_io_errors for why 88 */ + sysfs_print(io_error_halflife, c->error_decay * 88); + sysfs_print(io_error_limit, c->error_limit); + + sysfs_hprint(congested, + ((uint64_t) bch_get_congested(c)) << 9); + sysfs_print(congested_read_threshold_us, + c->congested_read_threshold_us); + sysfs_print(congested_write_threshold_us, + c->congested_write_threshold_us); + + sysfs_print(cutoff_writeback, bch_cutoff_writeback); + sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync); + + sysfs_print(active_journal_entries, fifo_used(&c->journal.pin)); + sysfs_printf(verify, "%i", c->verify); + sysfs_printf(key_merging_disabled, "%i", c->key_merging_disabled); + sysfs_printf(expensive_debug_checks, + "%i", c->expensive_debug_checks); + sysfs_printf(gc_always_rewrite, "%i", c->gc_always_rewrite); + sysfs_printf(btree_shrinker_disabled, "%i", c->shrinker_disabled); + sysfs_printf(copy_gc_enabled, "%i", c->copy_gc_enabled); + sysfs_printf(idle_max_writeback_rate, "%i", + c->idle_max_writeback_rate_enabled); + sysfs_printf(gc_after_writeback, "%i", c->gc_after_writeback); + sysfs_printf(io_disable, "%i", + test_bit(CACHE_SET_IO_DISABLE, &c->flags)); + + if (attr == &sysfs_bset_tree_stats) + return bch_bset_print_stats(c, buf); + + if (attr == &sysfs_feature_compat) + return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE); + if (attr == &sysfs_feature_ro_compat) + return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE); + if (attr == &sysfs_feature_incompat) + return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE); + + return 0; +} +SHOW_LOCKED(bch_cache_set) + +STORE(__bch_cache_set) +{ + struct cache_set *c = container_of(kobj, struct cache_set, kobj); + ssize_t v; + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + + if (attr == &sysfs_unregister) + bch_cache_set_unregister(c); + + if (attr == &sysfs_stop) + bch_cache_set_stop(c); + + if (attr == &sysfs_synchronous) { + bool sync = strtoul_or_return(buf); + + if (sync != CACHE_SYNC(&c->cache->sb)) { + SET_CACHE_SYNC(&c->cache->sb, sync); + bcache_write_super(c); + } + } + + if (attr == &sysfs_flash_vol_create) { + int r; + uint64_t v; + + strtoi_h_or_return(buf, v); + + r = bch_flash_dev_create(c, v); + if (r) + return r; + } + + if (attr == &sysfs_clear_stats) { + atomic_long_set(&c->writeback_keys_done, 0); + atomic_long_set(&c->writeback_keys_failed, 0); + + memset(&c->gc_stats, 0, sizeof(struct gc_stat)); + bch_cache_accounting_clear(&c->accounting); + } + + if (attr == &sysfs_trigger_gc) + force_wake_up_gc(c); + + if (attr == &sysfs_prune_cache) { + struct shrink_control sc; + + sc.gfp_mask = GFP_KERNEL; + sc.nr_to_scan = strtoul_or_return(buf); + if (c->shrink) + c->shrink->scan_objects(c->shrink, &sc); + } + + sysfs_strtoul_clamp(congested_read_threshold_us, + c->congested_read_threshold_us, + 0, UINT_MAX); + sysfs_strtoul_clamp(congested_write_threshold_us, + c->congested_write_threshold_us, + 0, UINT_MAX); + + if (attr == &sysfs_errors) { + v = __sysfs_match_string(error_actions, -1, buf); + if (v < 0) + return v; + + c->on_error = v; + } + + sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX); + + /* See count_io_errors() for why 88 */ + if (attr == &sysfs_io_error_halflife) { + unsigned long v = 0; + ssize_t ret; + + ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX); + if (!ret) { + c->error_decay = v / 88; + return size; + } + return ret; + } + + if (attr == &sysfs_io_disable) { + v = strtoul_or_return(buf); + if (v) { + if (test_and_set_bit(CACHE_SET_IO_DISABLE, + &c->flags)) + pr_warn("CACHE_SET_IO_DISABLE already set\n"); + } else { + if (!test_and_clear_bit(CACHE_SET_IO_DISABLE, + &c->flags)) + pr_warn("CACHE_SET_IO_DISABLE already cleared\n"); + } + } + + sysfs_strtoul_clamp(journal_delay_ms, + c->journal_delay_ms, + 0, USHRT_MAX); + sysfs_strtoul_bool(verify, c->verify); + sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled); + sysfs_strtoul(expensive_debug_checks, c->expensive_debug_checks); + sysfs_strtoul_bool(gc_always_rewrite, c->gc_always_rewrite); + sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled); + sysfs_strtoul_bool(copy_gc_enabled, c->copy_gc_enabled); + sysfs_strtoul_bool(idle_max_writeback_rate, + c->idle_max_writeback_rate_enabled); + + /* + * write gc_after_writeback here may overwrite an already set + * BCH_DO_AUTO_GC, it doesn't matter because this flag will be + * set in next chance. + */ + sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1); + + return size; +} +STORE_LOCKED(bch_cache_set) + +SHOW(bch_cache_set_internal) +{ + struct cache_set *c = container_of(kobj, struct cache_set, internal); + + return bch_cache_set_show(&c->kobj, attr, buf); +} + +STORE(bch_cache_set_internal) +{ + struct cache_set *c = container_of(kobj, struct cache_set, internal); + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + + return bch_cache_set_store(&c->kobj, attr, buf, size); +} + +static void bch_cache_set_internal_release(struct kobject *k) +{ +} + +static struct attribute *bch_cache_set_attrs[] = { + &sysfs_unregister, + &sysfs_stop, + &sysfs_synchronous, + &sysfs_journal_delay_ms, + &sysfs_flash_vol_create, + + &sysfs_bucket_size, + &sysfs_block_size, + &sysfs_tree_depth, + &sysfs_root_usage_percent, + &sysfs_btree_cache_size, + &sysfs_cache_available_percent, + + &sysfs_average_key_size, + + &sysfs_errors, + &sysfs_io_error_limit, + &sysfs_io_error_halflife, + &sysfs_congested, + &sysfs_congested_read_threshold_us, + &sysfs_congested_write_threshold_us, + &sysfs_clear_stats, + NULL +}; +ATTRIBUTE_GROUPS(bch_cache_set); +KTYPE(bch_cache_set); + +static struct attribute *bch_cache_set_internal_attrs[] = { + &sysfs_active_journal_entries, + + sysfs_time_stats_attribute_list(btree_gc, sec, ms) + sysfs_time_stats_attribute_list(btree_split, sec, us) + sysfs_time_stats_attribute_list(btree_sort, ms, us) + sysfs_time_stats_attribute_list(btree_read, ms, us) + + &sysfs_btree_nodes, + &sysfs_btree_used_percent, + &sysfs_btree_cache_max_chain, + + &sysfs_bset_tree_stats, + &sysfs_cache_read_races, + &sysfs_reclaim, + &sysfs_reclaimed_journal_buckets, + &sysfs_flush_write, + &sysfs_writeback_keys_done, + &sysfs_writeback_keys_failed, + + &sysfs_trigger_gc, + &sysfs_prune_cache, +#ifdef CONFIG_BCACHE_DEBUG + &sysfs_verify, + &sysfs_key_merging_disabled, + &sysfs_expensive_debug_checks, +#endif + &sysfs_gc_always_rewrite, + &sysfs_btree_shrinker_disabled, + &sysfs_copy_gc_enabled, + &sysfs_idle_max_writeback_rate, + &sysfs_gc_after_writeback, + &sysfs_io_disable, + &sysfs_cutoff_writeback, + &sysfs_cutoff_writeback_sync, + &sysfs_feature_compat, + &sysfs_feature_ro_compat, + &sysfs_feature_incompat, + NULL +}; +ATTRIBUTE_GROUPS(bch_cache_set_internal); +KTYPE(bch_cache_set_internal); + +static int __bch_cache_cmp(const void *l, const void *r) +{ + cond_resched(); + return *((uint16_t *)r) - *((uint16_t *)l); +} + +SHOW(__bch_cache) +{ + struct cache *ca = container_of(kobj, struct cache, kobj); + + sysfs_hprint(bucket_size, bucket_bytes(ca)); + sysfs_hprint(block_size, block_bytes(ca)); + sysfs_print(nbuckets, ca->sb.nbuckets); + sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9); + sysfs_hprint(btree_written, + atomic_long_read(&ca->btree_sectors_written) << 9); + sysfs_hprint(metadata_written, + (atomic_long_read(&ca->meta_sectors_written) + + atomic_long_read(&ca->btree_sectors_written)) << 9); + + sysfs_print(io_errors, + atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT); + + if (attr == &sysfs_cache_replacement_policy) + return bch_snprint_string_list(buf, PAGE_SIZE, + cache_replacement_policies, + CACHE_REPLACEMENT(&ca->sb)); + + if (attr == &sysfs_priority_stats) { + struct bucket *b; + size_t n = ca->sb.nbuckets, i; + size_t unused = 0, available = 0, dirty = 0, meta = 0; + uint64_t sum = 0; + /* Compute 31 quantiles */ + uint16_t q[31], *p, *cached; + ssize_t ret; + + cached = p = vmalloc(array_size(sizeof(uint16_t), + ca->sb.nbuckets)); + if (!p) + return -ENOMEM; + + mutex_lock(&ca->set->bucket_lock); + for_each_bucket(b, ca) { + if (!GC_SECTORS_USED(b)) + unused++; + if (GC_MARK(b) == GC_MARK_RECLAIMABLE) + available++; + if (GC_MARK(b) == GC_MARK_DIRTY) + dirty++; + if (GC_MARK(b) == GC_MARK_METADATA) + meta++; + } + + for (i = ca->sb.first_bucket; i < n; i++) + p[i] = ca->buckets[i].prio; + mutex_unlock(&ca->set->bucket_lock); + + sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL); + + while (n && + !cached[n - 1]) + --n; + + while (cached < p + n && + *cached == BTREE_PRIO) { + cached++; + n--; + } + + for (i = 0; i < n; i++) + sum += INITIAL_PRIO - cached[i]; + + if (n) + sum = div64_u64(sum, n); + + for (i = 0; i < ARRAY_SIZE(q); i++) + q[i] = INITIAL_PRIO - cached[n * (i + 1) / + (ARRAY_SIZE(q) + 1)]; + + vfree(p); + + ret = sysfs_emit(buf, + "Unused: %zu%%\n" + "Clean: %zu%%\n" + "Dirty: %zu%%\n" + "Metadata: %zu%%\n" + "Average: %llu\n" + "Sectors per Q: %zu\n" + "Quantiles: [", + unused * 100 / (size_t) ca->sb.nbuckets, + available * 100 / (size_t) ca->sb.nbuckets, + dirty * 100 / (size_t) ca->sb.nbuckets, + meta * 100 / (size_t) ca->sb.nbuckets, sum, + n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1)); + + for (i = 0; i < ARRAY_SIZE(q); i++) + ret += sysfs_emit_at(buf, ret, "%u ", q[i]); + ret--; + + ret += sysfs_emit_at(buf, ret, "]\n"); + + return ret; + } + + return 0; +} +SHOW_LOCKED(bch_cache) + +STORE(__bch_cache) +{ + struct cache *ca = container_of(kobj, struct cache, kobj); + ssize_t v; + + /* no user space access if system is rebooting */ + if (bcache_is_reboot) + return -EBUSY; + + if (attr == &sysfs_cache_replacement_policy) { + v = __sysfs_match_string(cache_replacement_policies, -1, buf); + if (v < 0) + return v; + + if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) { + mutex_lock(&ca->set->bucket_lock); + SET_CACHE_REPLACEMENT(&ca->sb, v); + mutex_unlock(&ca->set->bucket_lock); + + bcache_write_super(ca->set); + } + } + + if (attr == &sysfs_clear_stats) { + atomic_long_set(&ca->sectors_written, 0); + atomic_long_set(&ca->btree_sectors_written, 0); + atomic_long_set(&ca->meta_sectors_written, 0); + atomic_set(&ca->io_count, 0); + atomic_set(&ca->io_errors, 0); + } + + return size; +} +STORE_LOCKED(bch_cache) + +static struct attribute *bch_cache_attrs[] = { + &sysfs_bucket_size, + &sysfs_block_size, + &sysfs_nbuckets, + &sysfs_priority_stats, + &sysfs_written, + &sysfs_btree_written, + &sysfs_metadata_written, + &sysfs_io_errors, + &sysfs_clear_stats, + &sysfs_cache_replacement_policy, + NULL +}; +ATTRIBUTE_GROUPS(bch_cache); +KTYPE(bch_cache); -- cgit v1.3.1