On Wed, Jan 3, 2024 at 9:08 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Wed, 2024-01-03 at 10:19 -0500, Chuck Lever wrote:
> > From: Chuck Lever <chuck.lever@xxxxxxxxxx>
> >
> > De-duplicate the same functionality in several places by hoisting
> > the is_dot_dotdot() function into linux/fs.h.
> >
> > Suggested-by: Amir Goldstein <amir73il@xxxxxxxxx>
> > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> > ---
> > fs/crypto/fname.c | 8 +-------
> > fs/ecryptfs/crypto.c | 10 ----------
> > fs/exportfs/expfs.c | 4 +---
> > fs/f2fs/f2fs.h | 11 -----------
> > include/linux/fs.h | 9 +++++++++
> > 5 files changed, 11 insertions(+), 31 deletions(-)
> >
> > diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
> > index 7b3fc189593a..0ad52fbe51c9 100644
> > --- a/fs/crypto/fname.c
> > +++ b/fs/crypto/fname.c
> > @@ -74,13 +74,7 @@ struct fscrypt_nokey_name {
> >
> > static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
> > {
> > - if (str->len == 1 && str->name[0] == '.')
> > - return true;
> > -
> > - if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
> > - return true;
> > -
> > - return false;
> > + return is_dot_dotdot(str->name, str->len);
> > }
> >
> > /**
> > diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
> > index 03bd55069d86..2fe0f3af1a08 100644
> > --- a/fs/ecryptfs/crypto.c
> > +++ b/fs/ecryptfs/crypto.c
> > @@ -1949,16 +1949,6 @@ int ecryptfs_encrypt_and_encode_filename(
> > return rc;
> > }
> >
> > -static bool is_dot_dotdot(const char *name, size_t name_size)
> > -{
> > - if (name_size == 1 && name[0] == '.')
> > - return true;
> > - else if (name_size == 2 && name[0] == '.' && name[1] == '.')
> > - return true;
> > -
> > - return false;
> > -}
> > -
> > /**
> > * ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext
> > * @plaintext_name: The plaintext name
> > diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
> > index 84af58eaf2ca..07ea3d62b298 100644
> > --- a/fs/exportfs/expfs.c
> > +++ b/fs/exportfs/expfs.c
> > @@ -255,9 +255,7 @@ static bool filldir_one(struct dir_context *ctx, const char *name, int len,
> > container_of(ctx, struct getdents_callback, ctx);
> >
> > buf->sequence++;
> > - /* Ignore the '.' and '..' entries */
> > - if ((len > 2 || name[0] != '.' || (len == 2 && name[1] != '.')) &&
> > - buf->ino == ino && len <= NAME_MAX) {
> > + if (buf->ino == ino && len <= NAME_MAX && !is_dot_dotdot(name, len)) {
> > memcpy(buf->name, name, len);
> > buf->name[len] = '\0';
> > buf->found = 1;
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 9043cedfa12b..322a3b8a3533 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -3368,17 +3368,6 @@ static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
> > return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
> > }
> >
> > -static inline bool is_dot_dotdot(const u8 *name, size_t len)
> > -{
> > - if (len == 1 && name[0] == '.')
> > - return true;
> > -
> > - if (len == 2 && name[0] == '.' && name[1] == '.')
> > - return true;
> > -
> > - return false;
> > -}
> > -
> > static inline void *f2fs_kmalloc(struct f2fs_sb_info *sbi,
> > size_t size, gfp_t flags)
> > {
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index 98b7a7a8c42e..179eea797c22 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2846,6 +2846,15 @@ extern bool path_is_under(const struct path *, const struct path *);
> >
> > extern char *file_path(struct file *, char *, int);
> >
> > +static inline bool is_dot_dotdot(const char *name, size_t len)
> > +{
> > + if (len == 1 && name[0] == '.')
> > + return true;
> > + if (len == 2 && name[0] == '.' && name[1] == '.')
> > + return true;
> > + return false;
> > +}
> > +
> > #include <linux/err.h>
> >
> > /* needed for stackable file system support */
> >
> >
>
> Looks good to me. I took a quick look to see if there were other open-
> coded versions, but I didn't see any.
>
The outstanding open-coded version that wasn't deduped is in
lookup_one_common(), which is the version that Trond used and
mentioned in his patch.
It is also a slightly more "efficient" version, but I have no idea if
that really matters.
In any case, having lookup_one_common() and get_name() use
the same helper is clearly prefered, because the check in lookup_one()
is the declared reason for the get_name() patch.
Thanks,
Amir.
