^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (C) 2011 Red Hat, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This file is released under the GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include "dm-block-manager.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include "dm-persistent-data-internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/dm-bufio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/crc32c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/rwsem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/device-mapper.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define DM_MSG_PREFIX "block manager"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /*----------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * This is a read/write semaphore with a couple of differences.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * i) There is a restriction on the number of concurrent read locks that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * may be held at once. This is just an implementation detail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * ii) Recursive locking attempts are detected and return EINVAL. A stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * trace is also emitted for the previous lock acquisition.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * iii) Priority is given to write locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #define MAX_HOLDERS 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #define MAX_STACK 10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) struct stack_store {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) unsigned int nr_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) unsigned long entries[MAX_STACK];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) struct block_lock {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) spinlock_t lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) __s32 count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct list_head waiters;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct task_struct *holders[MAX_HOLDERS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) struct stack_store traces[MAX_HOLDERS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct waiter {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) int wants_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) static unsigned __find_holder(struct block_lock *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) for (i = 0; i < MAX_HOLDERS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) if (lock->holders[i] == task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) BUG_ON(i == MAX_HOLDERS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /* call this *after* you increment lock->count */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) static void __add_holder(struct block_lock *lock, struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) unsigned h = __find_holder(lock, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) struct stack_store *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) get_task_struct(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) lock->holders[h] = task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) t = lock->traces + h;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) t->nr_entries = stack_trace_save(t->entries, MAX_STACK, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* call this *before* you decrement lock->count */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) static void __del_holder(struct block_lock *lock, struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) unsigned h = __find_holder(lock, task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) lock->holders[h] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) put_task_struct(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) static int __check_holder(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) for (i = 0; i < MAX_HOLDERS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) if (lock->holders[i] == current) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) DMERR("recursive lock detected in metadata");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) DMERR("previously held here:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) stack_trace_print(lock->traces[i].entries,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) lock->traces[i].nr_entries, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) DMERR("subsequent acquisition attempted here:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static void __wait(struct waiter *w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) set_current_state(TASK_UNINTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (!w->task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) static void __wake_waiter(struct waiter *w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) list_del(&w->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) task = w->task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) w->task = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) wake_up_process(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * We either wake a few readers or a single writer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) static void __wake_many(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) struct waiter *w, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) BUG_ON(lock->count < 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) list_for_each_entry_safe(w, tmp, &lock->waiters, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (lock->count >= MAX_HOLDERS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (w->wants_write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (lock->count > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) return; /* still read locked */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) lock->count = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) __add_holder(lock, w->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) __wake_waiter(w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) lock->count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) __add_holder(lock, w->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) __wake_waiter(w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) static void bl_init(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) spin_lock_init(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) lock->count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) INIT_LIST_HEAD(&lock->waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) for (i = 0; i < MAX_HOLDERS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) lock->holders[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) static int __available_for_read(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return lock->count >= 0 &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) lock->count < MAX_HOLDERS &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) list_empty(&lock->waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) static int bl_down_read(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) struct waiter w;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) spin_lock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) r = __check_holder(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) if (__available_for_read(lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) lock->count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) __add_holder(lock, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) get_task_struct(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) w.task = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) w.wants_write = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) list_add_tail(&w.list, &lock->waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) __wait(&w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) put_task_struct(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) static int bl_down_read_nonblock(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) spin_lock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) r = __check_holder(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) if (r)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) if (__available_for_read(lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) lock->count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) __add_holder(lock, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) r = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) r = -EWOULDBLOCK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) static void bl_up_read(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) spin_lock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) BUG_ON(lock->count <= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) __del_holder(lock, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) --lock->count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) if (!list_empty(&lock->waiters))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) __wake_many(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) static int bl_down_write(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) struct waiter w;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) spin_lock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) r = __check_holder(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (lock->count == 0 && list_empty(&lock->waiters)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) lock->count = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) __add_holder(lock, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) get_task_struct(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) w.task = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) w.wants_write = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * Writers given priority. We know there's only one mutator in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) * system, so ignoring the ordering reversal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) list_add(&w.list, &lock->waiters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) __wait(&w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) put_task_struct(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) static void bl_up_write(struct block_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) spin_lock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) __del_holder(lock, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) lock->count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) if (!list_empty(&lock->waiters))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) __wake_many(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) spin_unlock(&lock->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) static void report_recursive_bug(dm_block_t b, int r)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) if (r == -EINVAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) DMERR("recursive acquisition of block %llu requested.",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) (unsigned long long) b);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) #else /* !CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) #define bl_init(x) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) #define bl_down_read(x) 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) #define bl_down_read_nonblock(x) 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) #define bl_up_read(x) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) #define bl_down_write(x) 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) #define bl_up_write(x) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) #define report_recursive_bug(x, y) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) #endif /* CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) /*----------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * Block manager is currently implemented using dm-bufio. struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * dm_block_manager and struct dm_block map directly onto a couple of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * structs in the bufio interface. I want to retain the freedom to move
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * away from bufio in the future. So these structs are just cast within
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * this .c file, rather than making it through to the public interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) static struct dm_buffer *to_buffer(struct dm_block *b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) return (struct dm_buffer *) b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) dm_block_t dm_block_location(struct dm_block *b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) return dm_bufio_get_block_number(to_buffer(b));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) EXPORT_SYMBOL_GPL(dm_block_location);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) void *dm_block_data(struct dm_block *b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) return dm_bufio_get_block_data(to_buffer(b));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) EXPORT_SYMBOL_GPL(dm_block_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) struct buffer_aux {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) struct dm_block_validator *validator;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) int write_locked;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) #ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) struct block_lock lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) static void dm_block_manager_alloc_callback(struct dm_buffer *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) struct buffer_aux *aux = dm_bufio_get_aux_data(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) aux->validator = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) bl_init(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) static void dm_block_manager_write_callback(struct dm_buffer *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) struct buffer_aux *aux = dm_bufio_get_aux_data(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (aux->validator) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) aux->validator->prepare_for_write(aux->validator, (struct dm_block *) buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) dm_bufio_get_block_size(dm_bufio_get_client(buf)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) /*----------------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) * Public interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) *--------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) struct dm_block_manager {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) struct dm_bufio_client *bufio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) bool read_only:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) struct dm_block_manager *dm_block_manager_create(struct block_device *bdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) unsigned block_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) unsigned max_held_per_thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) struct dm_block_manager *bm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) bm = kmalloc(sizeof(*bm), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) if (!bm) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) r = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) bm->bufio = dm_bufio_client_create(bdev, block_size, max_held_per_thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) sizeof(struct buffer_aux),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) dm_block_manager_alloc_callback,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) dm_block_manager_write_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) if (IS_ERR(bm->bufio)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) r = PTR_ERR(bm->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) kfree(bm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) bm->read_only = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) return bm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) bad:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return ERR_PTR(r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) EXPORT_SYMBOL_GPL(dm_block_manager_create);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) void dm_block_manager_destroy(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) dm_bufio_client_destroy(bm->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) kfree(bm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) EXPORT_SYMBOL_GPL(dm_block_manager_destroy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) unsigned dm_bm_block_size(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) return dm_bufio_get_block_size(bm->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) EXPORT_SYMBOL_GPL(dm_bm_block_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) return dm_bufio_get_device_size(bm->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) static int dm_bm_validate_buffer(struct dm_block_manager *bm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) struct dm_buffer *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) struct buffer_aux *aux,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) struct dm_block_validator *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) if (unlikely(!aux->validator)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) if (!v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) r = v->check(v, (struct dm_block *) buf, dm_bufio_get_block_size(bm->bufio));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (unlikely(r)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) DMERR_LIMIT("%s validator check failed for block %llu", v->name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) (unsigned long long) dm_bufio_get_block_number(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) aux->validator = v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) if (unlikely(aux->validator != v)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) DMERR_LIMIT("validator mismatch (old=%s vs new=%s) for block %llu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) aux->validator->name, v ? v->name : "NULL",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) (unsigned long long) dm_bufio_get_block_number(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) int dm_bm_read_lock(struct dm_block_manager *bm, dm_block_t b,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) struct dm_block_validator *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) struct dm_block **result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) struct buffer_aux *aux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) void *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (IS_ERR(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) return PTR_ERR(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) aux = dm_bufio_get_aux_data(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) r = bl_down_read(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) if (unlikely(r)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) report_recursive_bug(b, r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) aux->write_locked = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) if (unlikely(r)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) bl_up_read(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) EXPORT_SYMBOL_GPL(dm_bm_read_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) int dm_bm_write_lock(struct dm_block_manager *bm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) dm_block_t b, struct dm_block_validator *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) struct dm_block **result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) struct buffer_aux *aux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) void *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) if (dm_bm_is_read_only(bm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) if (IS_ERR(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) return PTR_ERR(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) aux = dm_bufio_get_aux_data(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) r = bl_down_write(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) report_recursive_bug(b, r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) aux->write_locked = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) if (unlikely(r)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) bl_up_write(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) EXPORT_SYMBOL_GPL(dm_bm_write_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) int dm_bm_read_try_lock(struct dm_block_manager *bm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) dm_block_t b, struct dm_block_validator *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) struct dm_block **result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) struct buffer_aux *aux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) void *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) p = dm_bufio_get(bm->bufio, b, (struct dm_buffer **) result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) if (IS_ERR(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) return PTR_ERR(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) if (unlikely(!p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) return -EWOULDBLOCK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) aux = dm_bufio_get_aux_data(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) r = bl_down_read_nonblock(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) if (r < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) report_recursive_bug(b, r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) aux->write_locked = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (unlikely(r)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) bl_up_read(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) int dm_bm_write_lock_zero(struct dm_block_manager *bm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) dm_block_t b, struct dm_block_validator *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) struct dm_block **result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) struct buffer_aux *aux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) void *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (dm_bm_is_read_only(bm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) p = dm_bufio_new(bm->bufio, b, (struct dm_buffer **) result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) if (IS_ERR(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) return PTR_ERR(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) memset(p, 0, dm_bm_block_size(bm));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) aux = dm_bufio_get_aux_data(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) r = bl_down_write(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) if (r) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) dm_bufio_release(to_buffer(*result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) aux->write_locked = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) aux->validator = v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) EXPORT_SYMBOL_GPL(dm_bm_write_lock_zero);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) void dm_bm_unlock(struct dm_block *b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) struct buffer_aux *aux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) aux = dm_bufio_get_aux_data(to_buffer(b));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) if (aux->write_locked) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) dm_bufio_mark_buffer_dirty(to_buffer(b));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) bl_up_write(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) bl_up_read(&aux->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) dm_bufio_release(to_buffer(b));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) EXPORT_SYMBOL_GPL(dm_bm_unlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) int dm_bm_flush(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) if (dm_bm_is_read_only(bm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) return dm_bufio_write_dirty_buffers(bm->bufio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) EXPORT_SYMBOL_GPL(dm_bm_flush);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) dm_bufio_prefetch(bm->bufio, b, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) bool dm_bm_is_read_only(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) return (bm ? bm->read_only : true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) EXPORT_SYMBOL_GPL(dm_bm_is_read_only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) void dm_bm_set_read_only(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) if (bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) bm->read_only = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) void dm_bm_set_read_write(struct dm_block_manager *bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) if (bm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) bm->read_only = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) EXPORT_SYMBOL_GPL(dm_bm_set_read_write);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) return crc32c(~(u32) 0, data, len) ^ init_xor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) EXPORT_SYMBOL_GPL(dm_bm_checksum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) /*----------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) MODULE_DESCRIPTION("Immutable metadata library for dm");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) /*----------------------------------------------------------------*/
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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