diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 48 | ||||
| -rw-r--r-- | lib/Makefile | 3 | ||||
| -rw-r--r-- | lib/klist.c | 96 | ||||
| -rw-r--r-- | lib/string_helpers.c | 64 |
4 files changed, 183 insertions, 28 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0b504814e37..ce697e0b319 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -597,6 +597,19 @@ config RCU_TORTURE_TEST_RUNNABLE Say N here if you want the RCU torture tests to start only after being manually enabled via /proc. +config RCU_CPU_STALL_DETECTOR + bool "Check for stalled CPUs delaying RCU grace periods" + depends on CLASSIC_RCU + default n + help + This option causes RCU to printk information on which + CPUs are delaying the current grace period, but only when + the grace period extends for excessive time periods. + + Say Y if you want RCU to perform such checks. + + Say N if you are unsure. + config KPROBES_SANITY_TEST bool "Kprobes sanity tests" depends on DEBUG_KERNEL @@ -624,6 +637,28 @@ config BACKTRACE_SELF_TEST Say N if you are unsure. +config DEBUG_BLOCK_EXT_DEVT + bool "Force extended block device numbers and spread them" + depends on DEBUG_KERNEL + depends on BLOCK + default n + help + Conventionally, block device numbers are allocated from + predetermined contiguous area. However, extended block area + may introduce non-contiguous block device numbers. This + option forces most block device numbers to be allocated from + the extended space and spreads them to discover kernel or + userland code paths which assume predetermined contiguous + device number allocation. + + Note that turning on this debug option shuffles all the + device numbers for all IDE and SCSI devices including libata + ones, so root partition specified using device number + directly (via rdev or root=MAJ:MIN) won't work anymore. + Textual device names (root=/dev/sdXn) will continue to work. + + Say N if you are unsure. + config LKDTM tristate "Linux Kernel Dump Test Tool Module" depends on DEBUG_KERNEL @@ -661,10 +696,21 @@ config FAIL_PAGE_ALLOC config FAIL_MAKE_REQUEST bool "Fault-injection capability for disk IO" - depends on FAULT_INJECTION + depends on FAULT_INJECTION && BLOCK help Provide fault-injection capability for disk IO. +config FAIL_IO_TIMEOUT + bool "Faul-injection capability for faking disk interrupts" + depends on FAULT_INJECTION && BLOCK + help + Provide fault-injection capability on end IO handling. This + will make the block layer "forget" an interrupt as configured, + thus exercising the error handling. + + Only works with drivers that use the generic timeout handling, + for others it wont do anything. + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS && DEBUG_FS diff --git a/lib/Makefile b/lib/Makefile index 3b1f94bbe9d..44001af76a7 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -19,7 +19,8 @@ lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ - bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o + bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ + string_helpers.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/klist.c b/lib/klist.c index cca37f96faa..bbdd3015c2c 100644 --- a/lib/klist.c +++ b/lib/klist.c @@ -37,6 +37,37 @@ #include <linux/klist.h> #include <linux/module.h> +/* + * Use the lowest bit of n_klist to mark deleted nodes and exclude + * dead ones from iteration. + */ +#define KNODE_DEAD 1LU +#define KNODE_KLIST_MASK ~KNODE_DEAD + +static struct klist *knode_klist(struct klist_node *knode) +{ + return (struct klist *) + ((unsigned long)knode->n_klist & KNODE_KLIST_MASK); +} + +static bool knode_dead(struct klist_node *knode) +{ + return (unsigned long)knode->n_klist & KNODE_DEAD; +} + +static void knode_set_klist(struct klist_node *knode, struct klist *klist) +{ + knode->n_klist = klist; + /* no knode deserves to start its life dead */ + WARN_ON(knode_dead(knode)); +} + +static void knode_kill(struct klist_node *knode) +{ + /* and no knode should die twice ever either, see we're very humane */ + WARN_ON(knode_dead(knode)); + *(unsigned long *)&knode->n_klist |= KNODE_DEAD; +} /** * klist_init - Initialize a klist structure. @@ -79,7 +110,7 @@ static void klist_node_init(struct klist *k, struct klist_node *n) INIT_LIST_HEAD(&n->n_node); init_completion(&n->n_removed); kref_init(&n->n_ref); - n->n_klist = k; + knode_set_klist(n, k); if (k->get) k->get(n); } @@ -115,7 +146,7 @@ EXPORT_SYMBOL_GPL(klist_add_tail); */ void klist_add_after(struct klist_node *n, struct klist_node *pos) { - struct klist *k = pos->n_klist; + struct klist *k = knode_klist(pos); klist_node_init(k, n); spin_lock(&k->k_lock); @@ -131,7 +162,7 @@ EXPORT_SYMBOL_GPL(klist_add_after); */ void klist_add_before(struct klist_node *n, struct klist_node *pos) { - struct klist *k = pos->n_klist; + struct klist *k = knode_klist(pos); klist_node_init(k, n); spin_lock(&k->k_lock); @@ -144,9 +175,10 @@ static void klist_release(struct kref *kref) { struct klist_node *n = container_of(kref, struct klist_node, n_ref); + WARN_ON(!knode_dead(n)); list_del(&n->n_node); complete(&n->n_removed); - n->n_klist = NULL; + knode_set_klist(n, NULL); } static int klist_dec_and_del(struct klist_node *n) @@ -154,22 +186,29 @@ static int klist_dec_and_del(struct klist_node *n) return kref_put(&n->n_ref, klist_release); } -/** - * klist_del - Decrement the reference count of node and try to remove. - * @n: node we're deleting. - */ -void klist_del(struct klist_node *n) +static void klist_put(struct klist_node *n, bool kill) { - struct klist *k = n->n_klist; + struct klist *k = knode_klist(n); void (*put)(struct klist_node *) = k->put; spin_lock(&k->k_lock); + if (kill) + knode_kill(n); if (!klist_dec_and_del(n)) put = NULL; spin_unlock(&k->k_lock); if (put) put(n); } + +/** + * klist_del - Decrement the reference count of node and try to remove. + * @n: node we're deleting. + */ +void klist_del(struct klist_node *n) +{ + klist_put(n, true); +} EXPORT_SYMBOL_GPL(klist_del); /** @@ -206,7 +245,6 @@ void klist_iter_init_node(struct klist *k, struct klist_iter *i, struct klist_node *n) { i->i_klist = k; - i->i_head = &k->k_list; i->i_cur = n; if (n) kref_get(&n->n_ref); @@ -237,7 +275,7 @@ EXPORT_SYMBOL_GPL(klist_iter_init); void klist_iter_exit(struct klist_iter *i) { if (i->i_cur) { - klist_del(i->i_cur); + klist_put(i->i_cur, false); i->i_cur = NULL; } } @@ -258,27 +296,33 @@ static struct klist_node *to_klist_node(struct list_head *n) */ struct klist_node *klist_next(struct klist_iter *i) { - struct list_head *next; - struct klist_node *lnode = i->i_cur; - struct klist_node *knode = NULL; void (*put)(struct klist_node *) = i->i_klist->put; + struct klist_node *last = i->i_cur; + struct klist_node *next; spin_lock(&i->i_klist->k_lock); - if (lnode) { - next = lnode->n_node.next; - if (!klist_dec_and_del(lnode)) + + if (last) { + next = to_klist_node(last->n_node.next); + if (!klist_dec_and_del(last)) put = NULL; } else - next = i->i_head->next; + next = to_klist_node(i->i_klist->k_list.next); - if (next != i->i_head) { - knode = to_klist_node(next); - kref_get(&knode->n_ref); + i->i_cur = NULL; + while (next != to_klist_node(&i->i_klist->k_list)) { + if (likely(!knode_dead(next))) { + kref_get(&next->n_ref); + i->i_cur = next; + break; + } + next = to_klist_node(next->n_node.next); } - i->i_cur = knode; + spin_unlock(&i->i_klist->k_lock); - if (put && lnode) - put(lnode); - return knode; + + if (put && last) + put(last); + return i->i_cur; } EXPORT_SYMBOL_GPL(klist_next); diff --git a/lib/string_helpers.c b/lib/string_helpers.c new file mode 100644 index 00000000000..8347925030f --- /dev/null +++ b/lib/string_helpers.c @@ -0,0 +1,64 @@ +/* + * Helpers for formatting and printing strings + * + * Copyright 31 August 2008 James Bottomley + */ +#include <linux/kernel.h> +#include <linux/math64.h> +#include <linux/module.h> +#include <linux/string_helpers.h> + +/** + * string_get_size - get the size in the specified units + * @size: The size to be converted + * @units: units to use (powers of 1000 or 1024) + * @buf: buffer to format to + * @len: length of buffer + * + * This function returns a string formatted to 3 significant figures + * giving the size in the required units. Returns 0 on success or + * error on failure. @buf is always zero terminated. + * + */ +int string_get_size(u64 size, const enum string_size_units units, + char *buf, int len) +{ + const char *units_10[] = { "B", "KB", "MB", "GB", "TB", "PB", + "EB", "ZB", "YB", NULL}; + const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB", + "EiB", "ZiB", "YiB", NULL }; + const char **units_str[] = { + [STRING_UNITS_10] = units_10, + [STRING_UNITS_2] = units_2, + }; + const int divisor[] = { + [STRING_UNITS_10] = 1000, + [STRING_UNITS_2] = 1024, + }; + int i, j; + u64 remainder = 0, sf_cap; + char tmp[8]; + + tmp[0] = '\0'; + + for (i = 0; size > divisor[units] && units_str[units][i]; i++) + remainder = do_div(size, divisor[units]); + + sf_cap = size; + for (j = 0; sf_cap*10 < 1000; j++) + sf_cap *= 10; + + if (j) { + remainder *= 1000; + do_div(remainder, divisor[units]); + snprintf(tmp, sizeof(tmp), ".%03lld", + (unsigned long long)remainder); + tmp[j+1] = '\0'; + } + + snprintf(buf, len, "%lld%s%s", (unsigned long long)size, + tmp, units_str[units][i]); + + return 0; +} +EXPORT_SYMBOL(string_get_size); |