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| author | Theodore Ts'o <tytso@mit.edu> | 2013-11-08 06:14:53 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-11-08 06:14:53 +0100 |
| commit | dd1f723bf56bd96efc9d90e9e60dc511c79de48f (patch) | |
| tree | 3860500165c69c225ccd5121f2ffde93dfbf4f02 | |
| parent | ext4: remove unreachable code after ext4_can_extents_be_merged() (diff) | |
| download | linux-dd1f723bf56bd96efc9d90e9e60dc511c79de48f.tar.xz linux-dd1f723bf56bd96efc9d90e9e60dc511c79de48f.zip | |
ext4: use prandom_u32() instead of get_random_bytes()
Many of the uses of get_random_bytes() do not actually need
cryptographically secure random numbers. Replace those uses with a
call to prandom_u32(), which is faster and which doesn't consume
entropy from the /dev/random driver.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/ialloc.c | 2 | ||||
| -rw-r--r-- | fs/ext4/mmp.c | 2 | ||||
| -rw-r--r-- | fs/ext4/super.c | 7 |
3 files changed, 4 insertions, 7 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 137193ff389b..0ee59a6644e2 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -432,7 +432,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, ext4fs_dirhash(qstr->name, qstr->len, &hinfo); grp = hinfo.hash; } else - get_random_bytes(&grp, sizeof(grp)); + grp = prandom_u32(); 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 214461e42a05..04434ad3e8e0 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -259,7 +259,7 @@ static unsigned int mmp_new_seq(void) u32 new_seq; do { - get_random_bytes(&new_seq, sizeof(u32)); + new_seq = prandom_u32(); } while (new_seq > EXT4_MMP_SEQ_MAX); return new_seq; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d3a857bfae47..c977f4e4e63b 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3068,7 +3068,6 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb, { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_li_request *elr; - unsigned long rnd; elr = kzalloc(sizeof(*elr), GFP_KERNEL); if (!elr) @@ -3083,10 +3082,8 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb, * spread the inode table initialization requests * better. */ - get_random_bytes(&rnd, sizeof(rnd)); - elr->lr_next_sched = jiffies + (unsigned long)rnd % - (EXT4_DEF_LI_MAX_START_DELAY * HZ); - + elr->lr_next_sched = jiffies + (prandom_u32() % + (EXT4_DEF_LI_MAX_START_DELAY * HZ)); return elr; } |