| Message ID | 170438514228.129184.8854845947814287856.stgit@bazille.1015granger.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fix the fallback implementation of get_name | expand |
On Thu, Jan 4, 2024 at 6:19 PM Chuck Lever <cel@kernel.org> wrote: > > From: Chuck Lever <chuck.lever@oracle.com> > > De-duplicate the same functionality in several places by hoisting > the is_dot_dotdot() utility function into linux/fs.h. > > Suggested-by: Amir Goldstein <amir73il@gmail.com> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > Signed-off-by: Chuck Lever <chuck.lever@oracle.com> > --- > fs/crypto/fname.c | 8 +------- > fs/ecryptfs/crypto.c | 10 ---------- > fs/exportfs/expfs.c | 4 +--- > fs/f2fs/f2fs.h | 11 ----------- > fs/namei.c | 6 ++---- > include/linux/fs.h | 15 +++++++++++++++ > 6 files changed, 19 insertions(+), 35 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/fs/namei.c b/fs/namei.c > index 71c13b2990b4..2386a70667fa 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -2667,10 +2667,8 @@ static int lookup_one_common(struct mnt_idmap *idmap, > if (!len) > return -EACCES; > > - if (unlikely(name[0] == '.')) { > - if (len < 2 || (len == 2 && name[1] == '.')) > - return -EACCES; > - } > + if (is_dot_dotdot(name, len)) > + return -EACCES; > > while (len--) { > unsigned int c = *(const unsigned char *)name++; > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 98b7a7a8c42e..750c95a2b572 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -2846,6 +2846,21 @@ extern bool path_is_under(const struct path *, const struct path *); > > extern char *file_path(struct file *, char *, int); > > +/** > + * is_dot_dotdot - returns true only if @name is "." or ".." > + * @name: file name to check > + * @len: length of file name, in bytes > + * > + * Coded for efficiency. > + */ > +static inline bool is_dot_dotdot(const char *name, size_t len) > +{ > + if (unlikely(name[0] == '.')) > + if (len < 2 || (len == 2 && name[1] == '.')) > + return true; > + return false; > +} I hate to nag, but these double ifs look really odd in the context of a helper. Also, not sure if all callers guarantee the len > 0 I did not check. Like this? static inline bool is_dot_dotdot(const char *name, size_t len) { return len && unlikely(name[0] == '.') && (len < 2 || (len == 2 && name[1] == '.'); } Thanks, Amir.
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/fs/namei.c b/fs/namei.c index 71c13b2990b4..2386a70667fa 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2667,10 +2667,8 @@ static int lookup_one_common(struct mnt_idmap *idmap, if (!len) return -EACCES; - if (unlikely(name[0] == '.')) { - if (len < 2 || (len == 2 && name[1] == '.')) - return -EACCES; - } + if (is_dot_dotdot(name, len)) + return -EACCES; while (len--) { unsigned int c = *(const unsigned char *)name++; diff --git a/include/linux/fs.h b/include/linux/fs.h index 98b7a7a8c42e..750c95a2b572 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2846,6 +2846,21 @@ extern bool path_is_under(const struct path *, const struct path *); extern char *file_path(struct file *, char *, int); +/** + * is_dot_dotdot - returns true only if @name is "." or ".." + * @name: file name to check + * @len: length of file name, in bytes + * + * Coded for efficiency. + */ +static inline bool is_dot_dotdot(const char *name, size_t len) +{ + if (unlikely(name[0] == '.')) + if (len < 2 || (len == 2 && name[1] == '.')) + return true; + return false; +} + #include <linux/err.h> /* needed for stackable file system support */