| Message ID | 20160729160035.26626-1-tytso@mit.edu |
|---|---|
| State | New, archived |
| Headers | show |
Hi,
[auto build test WARNING on ext4/dev]
[also build test WARNING on v4.7 next-20160729]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Theodore-Ts-o/ext4-add-ability-to-control-the-pseudo-random-seed-used-by-ext4/20160730-001338
base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: x86_64-randconfig-s2-07300120 (attached as .config)
compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
fs/ext4/ialloc.c: In function 'find_group_orlov':
>> fs/ext4/ialloc.c:490: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'ext4_group_t'
fs/ext4/ialloc.c: In function 'ext4_orphan_get':
fs/ext4/ialloc.c:1155: warning: 'bit' may be used uninitialized in this function
vim +490 fs/ext4/ialloc.c
474 do_div(avefreec, ngroups);
475 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
476
477 if (S_ISDIR(mode) &&
478 ((parent == d_inode(sb->s_root)) ||
479 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
480 int best_ndir = inodes_per_group;
481 int ret = -1;
482
483 if (qstr) {
484 hinfo.hash_version = DX_HASH_HALF_MD4;
485 hinfo.seed = sbi->s_hash_seed;
486 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
487 grp = hinfo.hash;
488 } else {
489 grp = prandom_u32_state(&sbi->s_rnd_state);
> 490 pr_err("ext4 random: %lu\n", grp);
491 }
492 parent_group = (unsigned)grp % ngroups;
493 for (i = 0; i < ngroups; i++) {
494 g = (parent_group + i) % ngroups;
495 get_orlov_stats(sb, g, flex_size, &stats);
496 if (!stats.free_inodes)
497 continue;
498 if (stats.used_dirs >= best_ndir)
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi,
[auto build test WARNING on ext4/dev]
[also build test WARNING on v4.7 next-20160729]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Theodore-Ts-o/ext4-add-ability-to-control-the-pseudo-random-seed-used-by-ext4/20160730-001338
base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: m68k-allyesconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 4.9.0
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=m68k
All warnings (new ones prefixed by >>):
fs/ext4/ialloc.c: In function 'find_group_orlov':
>> fs/ext4/ialloc.c:490:4: warning: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'ext4_group_t' [-Wformat=]
pr_err("ext4 random: %lu\n", grp);
^
vim +490 fs/ext4/ialloc.c
474 do_div(avefreec, ngroups);
475 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
476
477 if (S_ISDIR(mode) &&
478 ((parent == d_inode(sb->s_root)) ||
479 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
480 int best_ndir = inodes_per_group;
481 int ret = -1;
482
483 if (qstr) {
484 hinfo.hash_version = DX_HASH_HALF_MD4;
485 hinfo.seed = sbi->s_hash_seed;
486 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
487 grp = hinfo.hash;
488 } else {
489 grp = prandom_u32_state(&sbi->s_rnd_state);
> 490 pr_err("ext4 random: %lu\n", grp);
491 }
492 parent_group = (unsigned)grp % ngroups;
493 for (i = 0; i < ngroups; i++) {
494 g = (parent_group + i) % ngroups;
495 get_orlov_stats(sb, g, flex_size, &stats);
496 if (!stats.free_inodes)
497 continue;
498 if (stats.used_dirs >= best_ndir)
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi,
[auto build test WARNING on ext4/dev]
[also build test WARNING on v4.7 next-20160729]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Theodore-Ts-o/ext4-add-ability-to-control-the-pseudo-random-seed-used-by-ext4/20160730-001338
base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: sparc64-allyesconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 5.4.0-6) 5.4.0 20160609
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64
All warnings (new ones prefixed by >>):
In file included from include/linux/printk.h:6:0,
from include/linux/kernel.h:13,
from include/linux/list.h:8,
from include/linux/preempt.h:10,
from include/linux/spinlock.h:50,
from include/linux/seqlock.h:35,
from include/linux/time.h:5,
from fs/ext4/ialloc.c:15:
fs/ext4/ialloc.c: In function 'find_group_orlov':
>> include/linux/kern_levels.h:4:18: warning: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'ext4_group_t {aka unsigned int}' [-Wformat=]
#define KERN_SOH "\001" /* ASCII Start Of Header */
^
include/linux/kern_levels.h:10:18: note: in expansion of macro 'KERN_SOH'
#define KERN_ERR KERN_SOH "3" /* error conditions */
^
include/linux/printk.h:264:9: note: in expansion of macro 'KERN_ERR'
printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^
>> fs/ext4/ialloc.c:490:4: note: in expansion of macro 'pr_err'
pr_err("ext4 random: %lu\n", grp);
^
vim +/pr_err +490 fs/ext4/ialloc.c
474 do_div(avefreec, ngroups);
475 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
476
477 if (S_ISDIR(mode) &&
478 ((parent == d_inode(sb->s_root)) ||
479 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
480 int best_ndir = inodes_per_group;
481 int ret = -1;
482
483 if (qstr) {
484 hinfo.hash_version = DX_HASH_HALF_MD4;
485 hinfo.seed = sbi->s_hash_seed;
486 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
487 grp = hinfo.hash;
488 } else {
489 grp = prandom_u32_state(&sbi->s_rnd_state);
> 490 pr_err("ext4 random: %lu\n", grp);
491 }
492 parent_group = (unsigned)grp % ngroups;
493 for (i = 0; i < ngroups; i++) {
494 g = (parent_group + i) % ngroups;
495 get_orlov_stats(sb, g, flex_size, &stats);
496 if (!stats.free_inodes)
497 continue;
498 if (stats.used_dirs >= best_ndir)
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index ea31931..3dbb03a 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -35,6 +35,7 @@ #include <linux/fscrypto.h> #include <linux/falloc.h> #include <linux/percpu-rwsem.h> +#include <linux/random.h> #ifdef __KERNEL__ #include <linux/compat.h> #endif @@ -1491,6 +1492,9 @@ struct ext4_sb_info { /* Precomputed FS UUID checksum for seeding other checksums */ __u32 s_csum_seed; + /* RND state for the file system */ + struct rnd_state s_rnd_state; + /* Reclaim extents from extent status tree */ struct shrinker s_es_shrinker; struct list_head s_es_list; /* List of inodes with reclaimable extents */ diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 35f3518..09a1458 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -485,8 +485,10 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, hinfo.seed = sbi->s_hash_seed; ext4fs_dirhash(qstr->name, qstr->len, &hinfo); grp = hinfo.hash; - } else - grp = prandom_u32(); + } else { + grp = prandom_u32_state(&sbi->s_rnd_state); + pr_err("ext4 random: %lu\n", grp); + } parent_group = (unsigned)grp % ngroups; for (i = 0; i < ngroups; i++) { g = (parent_group + i) % ngroups; diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 23d436d..99f69dc 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -258,12 +258,12 @@ exit_thread: * Get a random new sequence number but make sure it is not greater than * EXT4_MMP_SEQ_MAX. */ -static unsigned int mmp_new_seq(void) +static unsigned int mmp_new_seq(struct ext4_sb_info *sbi) { u32 new_seq; do { - new_seq = prandom_u32(); + new_seq = prandom_u32_state(&sbi->s_rnd_state); } while (new_seq > EXT4_MMP_SEQ_MAX); return new_seq; @@ -342,7 +342,7 @@ skip: /* * write a new random sequence number. */ - seq = mmp_new_seq(); + seq = mmp_new_seq(EXT4_SB(sb)); mmp->mmp_seq = cpu_to_le32(seq); retval = write_mmp_block(sb, bh); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c13a4e4..2c86b98 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2969,7 +2969,7 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb, * spread the inode table initialization requests * better. */ - elr->lr_next_sched = jiffies + (prandom_u32() % + elr->lr_next_sched = jiffies + (prandom_u32_state(&sbi->s_rnd_state) % (EXT4_DEF_LI_MAX_START_DELAY * HZ)); return elr; } @@ -3274,6 +3274,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) if (sb->s_bdev->bd_part) sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part, sectors[1]); + _prandom_seed(&sbi->s_rnd_state, 0, true); /* Cleanup superblock name */ strreplace(sb->s_id, '/', '!'); diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index 1420a3c..f74d34b 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -26,6 +26,7 @@ typedef enum { attr_feature, attr_pointer_ui, attr_pointer_atomic, + attr_prandom_seed, } attr_id_t; typedef enum { @@ -90,6 +91,21 @@ static ssize_t inode_readahead_blks_store(struct ext4_attr *a, return count; } +static ssize_t prandom_seed_store(struct ext4_attr *a, + struct ext4_sb_info *sbi, + const char *buf, size_t count) +{ + unsigned long t; + int ret; + + ret = kstrtoul(skip_spaces(buf), 0, &t); + if (ret) + return ret; + + _prandom_seed(&sbi->s_rnd_state, t, false); + return count; +} + static ssize_t reserved_clusters_store(struct ext4_attr *a, struct ext4_sb_info *sbi, const char *buf, size_t count) @@ -178,6 +194,7 @@ EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); +EXT4_ATTR(prandom_seed, 0200, prandom_seed); EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst); EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); @@ -216,6 +233,7 @@ static struct attribute *ext4_attrs[] = { ATTR_LIST(errors_count), ATTR_LIST(first_error_time), ATTR_LIST(last_error_time), + ATTR_LIST(prandom_seed), NULL, }; @@ -313,6 +331,8 @@ static ssize_t ext4_attr_store(struct kobject *kobj, return inode_readahead_blks_store(a, sbi, buf, len); case attr_trigger_test_error: return trigger_test_error(a, sbi, buf, len); + case attr_prandom_seed: + return prandom_seed_store(a, sbi, buf, len); } return 0; } diff --git a/include/linux/random.h b/include/linux/random.h index e47e533..64b70a8 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -45,6 +45,7 @@ struct rnd_state { __u32 s1, s2, s3, s4; }; +void _prandom_seed(struct rnd_state *state, u32 seed, bool mix_with_hwseed); u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/lib/random32.c b/lib/random32.c index 510d1ce..5134111 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -157,8 +157,7 @@ static u32 __extract_hwseed(void) return val; } -static void prandom_seed_early(struct rnd_state *state, u32 seed, - bool mix_with_hwseed) +void _prandom_seed(struct rnd_state *state, u32 seed, bool mix_with_hwseed) { #define LCG(x) ((x) * 69069U) /* super-duper LCG */ #define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0) @@ -167,6 +166,7 @@ static void prandom_seed_early(struct rnd_state *state, u32 seed, state->s3 = __seed(HWSEED() ^ LCG(state->s2), 16U); state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U); } +EXPORT_SYMBOL(_prandom_seed); /** * prandom_seed - add entropy to pseudo random number generator @@ -204,7 +204,7 @@ static int __init prandom_init(void) struct rnd_state *state = &per_cpu(net_rand_state, i); u32 weak_seed = (i + jiffies) ^ random_get_entropy(); - prandom_seed_early(state, weak_seed, true); + _prandom_seed(state, weak_seed, true); prandom_warmup(state); } @@ -429,7 +429,7 @@ static void __init prandom_state_selftest(void) for (i = 0; i < ARRAY_SIZE(test1); i++) { struct rnd_state state; - prandom_seed_early(&state, test1[i].seed, false); + _prandom_seed(&state, test1[i].seed, false); prandom_warmup(&state); if (test1[i].result != prandom_u32_state(&state)) @@ -444,7 +444,7 @@ static void __init prandom_state_selftest(void) for (i = 0; i < ARRAY_SIZE(test2); i++) { struct rnd_state state; - prandom_seed_early(&state, test2[i].seed, false); + _prandom_seed(&state, test2[i].seed, false); prandom_warmup(&state); for (j = 0; j < test2[i].iteration - 1; j++)
Ext4 uses a pseudo-random generator in a few places: to spread out directories when htree is not enabled; to randomize thethe wait times for MMP backoff and lazy inode table initialization. For benchmarking purposes, it's useful to control the psueorandom number seed, expose this via /sys/fs/ext4/<dev>/prandom_seed. Signed-off-by: Theodore Ts'o <tytso@mit.edu> --- fs/ext4/ext4.h | 4 ++++ fs/ext4/ialloc.c | 6 ++++-- fs/ext4/mmp.c | 6 +++--- fs/ext4/super.c | 3 ++- fs/ext4/sysfs.c | 20 ++++++++++++++++++++ include/linux/random.h | 1 + lib/random32.c | 10 +++++----- 7 files changed, 39 insertions(+), 11 deletions(-)