diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ubifs/debug.c | 91 |
1 files changed, 50 insertions, 41 deletions
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c index b801af7837e9..eef109a1a927 100644 --- a/fs/ubifs/debug.c +++ b/fs/ubifs/debug.c @@ -27,11 +27,12 @@ * various local functions of those subsystems. */ -#include "ubifs.h" #include <linux/module.h> #include <linux/debugfs.h> #include <linux/math64.h> #include <linux/uaccess.h> +#include <linux/random.h> +#include "ubifs.h" #ifdef CONFIG_UBIFS_FS_DEBUG @@ -2535,17 +2536,10 @@ error_dump: return 0; } -/* Failure mode for recovery testing */ - -#define chance(n, d) (simple_rand() <= (n) * 32768LL / (d)) - -static unsigned int next; -static int simple_rand(void) +static inline int chance(unsigned int n, unsigned int out_of) { - if (next == 0) - next = current->pid; - next = next * 1103515245 + 12345; - return (next >> 16) & 32767; + return !!((random32() % out_of) + 1 <= n); + } static int power_cut_emulated(struct ubifs_info *c, int lnum, int write) @@ -2557,33 +2551,37 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write) if (!d->pc_cnt) { /* First call - decide delay to the power cut */ if (chance(1, 2)) { - unsigned int delay = 1 << (simple_rand() >> 11); + unsigned long delay; if (chance(1, 2)) { d->pc_delay = 1; - d->pc_timeout = jiffies + - msecs_to_jiffies(delay); - ubifs_warn("failing after %ums", delay); + /* Fail withing 1 minute */ + delay = random32() % 60000; + d->pc_timeout = jiffies; + d->pc_timeout += msecs_to_jiffies(delay); + ubifs_warn("failing after %lums", delay); } else { d->pc_delay = 2; + delay = random32() % 10000; + /* Fail within 10000 operations */ d->pc_cnt_max = delay; - ubifs_warn("failing after %u calls", delay); + ubifs_warn("failing after %lu calls", delay); } } + d->pc_cnt += 1; } + /* Determine if failure delay has expired */ - if (d->pc_delay == 1) { - if (time_before(jiffies, d->pc_timeout)) + if (d->pc_delay == 1 && time_before(jiffies, d->pc_timeout)) return 0; - } else if (d->pc_delay == 2) - if (d->pc_cnt++ < d->pc_cnt_max) + if (d->pc_delay == 2 && d->pc_cnt++ < d->pc_cnt_max) return 0; + if (lnum == UBIFS_SB_LNUM) { - if (write) { - if (chance(1, 2)) - return 0; - } else if (chance(19, 20)) + if (write && chance(1, 2)) + return 0; + if (chance(19, 20)) return 0; ubifs_warn("failing in super block LEB %d", lnum); } else if (lnum == UBIFS_MST_LNUM || lnum == UBIFS_MST_LNUM + 1) { @@ -2591,24 +2589,21 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write) return 0; ubifs_warn("failing in master LEB %d", lnum); } else if (lnum >= UBIFS_LOG_LNUM && lnum <= c->log_last) { - if (write) { - if (chance(99, 100)) - return 0; - } else if (chance(399, 400)) + if (write && chance(99, 100)) + return 0; + if (chance(399, 400)) return 0; ubifs_warn("failing in log LEB %d", lnum); } else if (lnum >= c->lpt_first && lnum <= c->lpt_last) { - if (write) { - if (chance(7, 8)) - return 0; - } else if (chance(19, 20)) + if (write && chance(7, 8)) + return 0; + if (chance(19, 20)) return 0; ubifs_warn("failing in LPT LEB %d", lnum); } else if (lnum >= c->orph_first && lnum <= c->orph_last) { - if (write) { - if (chance(1, 2)) - return 0; - } else if (chance(9, 10)) + if (write && chance(1, 2)) + return 0; + if (chance(9, 10)) return 0; ubifs_warn("failing in orphan LEB %d", lnum); } else if (lnum == c->ihead_lnum) { @@ -2636,18 +2631,32 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write) } d->pc_happened = 1; + ubifs_warn("========== Power cut emulated =========="); dump_stack(); return 1; } -static void cut_data(const void *buf, int len) +static void cut_data(const void *buf, unsigned int len) { - int flen, i; + unsigned int from, to, i, ffs = chance(1, 2); unsigned char *p = (void *)buf; - flen = (len * (long long)simple_rand()) >> 15; - for (i = flen; i < len; i++) - p[i] = 0xff; + from = random32() % (len + 1); + if (chance(1, 2)) + to = random32() % (len - from + 1); + else + to = len; + + if (from < to) + ubifs_warn("filled bytes %u-%u with %s", from, to - 1, + ffs ? "0xFFs" : "random data"); + + if (ffs) + for (i = from; i < to; i++) + p[i] = 0xFF; + else + for (i = from; i < to; i++) + p[i] = random32() % 0x100; } int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf, |