From: Eric Biggers <[email protected]> Previously fscrypt_fname_alloc_buffer() was used to allocate buffers for both presented (decrypted or encoded) and encrypted filenames. That was confusing, because it had to allocate the worst-case size for either, e.g. including NUL-padding even when it was meaningless.
But now that fscrypt_setup_filename() no longer calls it, it is only used in the ->get_link() and ->readdir() paths, which specifically want a buffer for presented filenames. Therefore, switch the behavior over to allocating the buffer for presented filenames only. Signed-off-by: Eric Biggers <[email protected]> --- fs/crypto/fname.c | 29 ++++++++++++++--------------- include/linux/fscrypt_notsupp.h | 2 +- 2 files changed, 15 insertions(+), 16 deletions(-) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 65424b89a1d1..44ddd094b7c5 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -204,37 +204,36 @@ u32 fscrypt_fname_encrypted_size(const struct inode *inode, u32 ilen) EXPORT_SYMBOL(fscrypt_fname_encrypted_size); /** - * fscrypt_fname_crypto_alloc_obuff() - + * fscrypt_fname_alloc_buffer - allocate a buffer for presented filenames * - * Allocates an output buffer that is sufficient for the crypto operation - * specified by the context and the direction. + * Allocate a buffer that is large enough to hold any decrypted or encoded + * filename (null-terminated), for the given maximum encrypted filename length. + * + * Return: 0 on success, -errno on failure */ int fscrypt_fname_alloc_buffer(const struct inode *inode, - u32 ilen, struct fscrypt_str *crypto_str) + u32 max_encrypted_len, + struct fscrypt_str *crypto_str) { - u32 olen = fscrypt_fname_encrypted_size(inode, ilen); const u32 max_encoded_len = max_t(u32, BASE64_CHARS(FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE), 1 + BASE64_CHARS(sizeof(struct fscrypt_digested_name))); + u32 max_presented_len; - crypto_str->len = olen; - olen = max(olen, max_encoded_len); + max_presented_len = max(max_encoded_len, max_encrypted_len); - /* - * Allocated buffer can hold one more character to null-terminate the - * string - */ - crypto_str->name = kmalloc(olen + 1, GFP_NOFS); - if (!(crypto_str->name)) + crypto_str->name = kmalloc(max_presented_len + 1, GFP_NOFS); + if (!crypto_str->name) return -ENOMEM; + crypto_str->len = max_presented_len; return 0; } EXPORT_SYMBOL(fscrypt_fname_alloc_buffer); /** - * fscrypt_fname_crypto_free_buffer() - + * fscrypt_fname_free_buffer - free the buffer for presented filenames * - * Frees the buffer allocated for crypto operation. + * Free the buffer allocated by fscrypt_fname_alloc_buffer(). */ void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str) { diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index 0962f504aa91..c9592e307df5 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -140,7 +140,7 @@ static inline u32 fscrypt_fname_encrypted_size(const struct inode *inode, } static inline int fscrypt_fname_alloc_buffer(const struct inode *inode, - u32 ilen, + u32 max_encrypted_len, struct fscrypt_str *crypto_str) { return -EOPNOTSUPP; -- 2.15.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
