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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-10-05 17:43:38 +0300 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-10-12 02:42:58 +0300 |
| commit | 8b3ccbc1f1f91847160951aa15dd27c22dddcb49 (patch) | |
| tree | b145d918cbcfc9c326136e1939d8b787c9983055 /fs/ext4 | |
| parent | 81895a65ec63ee1daec3255dc1a06675d2fbe915 (diff) | |
| download | linux-8b3ccbc1f1f91847160951aa15dd27c22dddcb49.tar.xz | |
treewide: use prandom_u32_max() when possible, part 2
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done by hand, covering things that coccinelle could not do on its own.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext2, ext4, and sbitmap
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/ialloc.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 208b87ce8858..7575aa359675 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -463,10 +463,9 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, hinfo.hash_version = DX_HASH_HALF_MD4; hinfo.seed = sbi->s_hash_seed; ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo); - grp = hinfo.hash; + parent_group = hinfo.hash % ngroups; } else - grp = prandom_u32(); - parent_group = (unsigned)grp % ngroups; + parent_group = prandom_u32_max(ngroups); for (i = 0; i < ngroups; i++) { g = (parent_group + i) % ngroups; get_orlov_stats(sb, g, flex_size, &stats); |