On Tue, Nov 17, 2020 at 04:03:15AM +0000, Daniel Rosenberg wrote:
> Expand f2fs's casefolding support to include encrypted directories. To
> index casefolded+encrypted directories, we use the SipHash of the
> casefolded name, keyed by a key derived from the directory's fscrypt
> master key. This ensures that the dirhash doesn't leak information
> about the plaintext filenames.
>
> Encryption keys are unavailable during roll-forward recovery, so we
> can't compute the dirhash when recovering a new dentry in an encrypted +
> casefolded directory. To avoid having to force a checkpoint when a new
> file is fsync'ed, store the dirhash on-disk appended to i_name.
>
> This patch incorporates work by Eric Biggers <[email protected]>
> and Jaegeuk Kim <[email protected]>.
>
> Co-developed-by: Eric Biggers <[email protected]>
> Signed-off-by: Eric Biggers <[email protected]>
> Signed-off-by: Daniel Rosenberg <[email protected]>
> ---
> fs/f2fs/dir.c | 89 +++++++++++++++++++++++++++++++++++++---------
> fs/f2fs/f2fs.h | 8 +++--
> fs/f2fs/hash.c | 11 +++++-
> fs/f2fs/inline.c | 4 +++
> fs/f2fs/recovery.c | 12 ++++++-
> fs/f2fs/super.c | 6 ----
> 6 files changed, 103 insertions(+), 27 deletions(-)
>
> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
> index 71fdf5076461..0adc6bcfb5c0 100644
> --- a/fs/f2fs/dir.c
> +++ b/fs/f2fs/dir.c
> @@ -5,6 +5,7 @@
> * Copyright (c) 2012 Samsung Electronics Co., Ltd.
> * http://www.samsung.com/
> */
> +#include <asm/unaligned.h>
> #include <linux/fs.h>
> #include <linux/f2fs_fs.h>
> #include <linux/sched/signal.h>
> @@ -195,26 +196,53 @@ static struct f2fs_dir_entry *find_in_block(struct
> inode *dir,
> {
> struct f2fs_dentry_block *dentry_blk;
> struct f2fs_dentry_ptr d;
> + struct f2fs_dir_entry *res;
>
> dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
>
> make_dentry_ptr_block(dir, &d, dentry_blk);
> - return f2fs_find_target_dentry(&d, fname, max_slots);
> + res = f2fs_find_target_dentry(&d, fname, max_slots);
> + if (IS_ERR(res)) {
> + dentry_page = ERR_CAST(res);
> + res = NULL;
> + }
> + return res;
> }
What is the assignment to dentry_page supposed to be accomplishing? It looks
like it's meant to pass up errors from f2fs_find_target_dentry(), but it doesn't
do that.
> @@ -222,14 +250,20 @@ static bool f2fs_match_ci_name(const struct inode *dir,
> const struct qstr *name,
> * fall back to treating them as opaque byte sequences.
> */
> if (sb_has_strict_encoding(sb) || name->len != entry.len)
> - return false;
> - return !memcmp(name->name, entry.name, name->len);
> + res = 0;
> + else
> + res = memcmp(name->name, entry.name, name->len) == 0;
> + } else {
> + /* utf8_strncasecmp_folded returns 0 on match */
> + res = (res == 0);
> }
The following might be easier to understand:
/*
* In strict mode, ignore invalid names. In non-strict mode, fall back
* to treating them as opaque byte sequences.
*/
if (res < 0 && !sb_has_strict_encoding(sb)) {
res = name->len == entry.len &&
memcmp(name->name, entry.name, name->len) == 0;
} else {
/* utf8_strncasecmp_folded returns 0 on match */
res = (res == 0);
}
> @@ -273,10 +308,14 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(const
> struct f2fs_dentry_ptr *d,
> continue;
> }
>
> - if (de->hash_code == fname->hash &&
> - f2fs_match_name(d->inode, fname, d->filename[bit_pos],
> - le16_to_cpu(de->name_len)))
> - goto found;
> + if (de->hash_code == fname->hash) {
> + res = f2fs_match_name(d->inode, fname,
> d->filename[bit_pos],
> + le16_to_cpu(de->name_len));
> + if (res < 0)
> + return ERR_PTR(res);
> + else if (res)
> + goto found;
> + }
Overly long line here. Also 'else if' is unnecessary, just use 'if'.
- Eric
_______________________________________________
Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
