1 files changed, 183 insertions, 423 deletions

diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index ca2f5948c1ac..7dc4eb55913c 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -48,6 +48,12 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
 	return (mode == EXT4_ENCRYPTION_MODE_AES_256_CTS);
 }
 
+static unsigned max_name_len(struct inode *inode)
+{
+	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
+		EXT4_NAME_LEN;
+}
+
 /**
  * ext4_fname_encrypt() -
  *
@@ -55,41 +61,52 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
  * ciphertext. Errors are returned as negative numbers.  We trust the caller to
  * allocate sufficient memory to oname string.
  */
-static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_encrypt(struct inode *inode,
 			      const struct qstr *iname,
 			      struct ext4_str *oname)
 {
 	u32 ciphertext_len;
 	struct ablkcipher_request *req = NULL;
 	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct crypto_ablkcipher *tfm = ctx->ctfm;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	struct scatterlist sg[1];
-	char *workbuf;
+	struct scatterlist src_sg, dst_sg;
+	int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
+	char *workbuf, buf[32], *alloc_buf = NULL;
+	unsigned lim = max_name_len(inode);
 
-	if (iname->len <= 0 || iname->len > ctx->lim)
+	if (iname->len <= 0 || iname->len > lim)
 		return -EIO;
 
 	ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
 		EXT4_CRYPTO_BLOCK_SIZE : iname->len;
-	ciphertext_len = (ciphertext_len > ctx->lim)
-			? ctx->lim : ciphertext_len;
+	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
+	ciphertext_len = (ciphertext_len > lim)
+			? lim : ciphertext_len;
+
+	if (ciphertext_len <= sizeof(buf)) {
+		workbuf = buf;
+	} else {
+		alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
+		if (!alloc_buf)
+			return -ENOMEM;
+		workbuf = alloc_buf;
+	}
 
 	/* Allocate request */
 	req = ablkcipher_request_alloc(tfm, GFP_NOFS);
 	if (!req) {
 		printk_ratelimited(
 		    KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
+		kfree(alloc_buf);
 		return -ENOMEM;
 	}
 	ablkcipher_request_set_callback(req,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 		ext4_dir_crypt_complete, &ecr);
 
-	/* Map the workpage */
-	workbuf = kmap(ctx->workpage);
-
 	/* Copy the input */
 	memcpy(workbuf, iname->name, iname->len);
 	if (iname->len < ciphertext_len)
@@ -99,21 +116,16 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
 	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
 
 	/* Create encryption request */
-	sg_init_table(sg, 1);
-	sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
-	ablkcipher_request_set_crypt(req, sg, sg, iname->len, iv);
+	sg_init_one(&src_sg, workbuf, ciphertext_len);
+	sg_init_one(&dst_sg, oname->name, ciphertext_len);
+	ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
 	res = crypto_ablkcipher_encrypt(req);
 	if (res == -EINPROGRESS || res == -EBUSY) {
 		BUG_ON(req->base.data != &ecr);
 		wait_for_completion(&ecr.completion);
 		res = ecr.res;
 	}
-	if (res >= 0) {
-		/* Copy the result to output */
-		memcpy(oname->name, workbuf, ciphertext_len);
-		res = ciphertext_len;
-	}
-	kunmap(ctx->workpage);
+	kfree(alloc_buf);
 	ablkcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(
@@ -130,20 +142,21 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
  *	Errors are returned as negative numbers.
  *	We trust the caller to allocate sufficient memory to oname string.
  */
-static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_decrypt(struct inode *inode,
 			      const struct ext4_str *iname,
 			      struct ext4_str *oname)
 {
 	struct ext4_str tmp_in[2], tmp_out[1];
 	struct ablkcipher_request *req = NULL;
 	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist sg[1];
-	struct crypto_ablkcipher *tfm = ctx->ctfm;
+	struct scatterlist src_sg, dst_sg;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	char *workbuf;
+	unsigned lim = max_name_len(inode);
 
-	if (iname->len <= 0 || iname->len > ctx->lim)
+	if (iname->len <= 0 || iname->len > lim)
 		return -EIO;
 
 	tmp_in[0].name = iname->name;
@@ -161,31 +174,19 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 		ext4_dir_crypt_complete, &ecr);
 
-	/* Map the workpage */
-	workbuf = kmap(ctx->workpage);
-
-	/* Copy the input */
-	memcpy(workbuf, iname->name, iname->len);
-
 	/* Initialize IV */
 	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
 
 	/* Create encryption request */
-	sg_init_table(sg, 1);
-	sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
-	ablkcipher_request_set_crypt(req, sg, sg, iname->len, iv);
+	sg_init_one(&src_sg, iname->name, iname->len);
+	sg_init_one(&dst_sg, oname->name, oname->len);
+	ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
 	res = crypto_ablkcipher_decrypt(req);
 	if (res == -EINPROGRESS || res == -EBUSY) {
 		BUG_ON(req->base.data != &ecr);
 		wait_for_completion(&ecr.completion);
 		res = ecr.res;
 	}
-	if (res >= 0) {
-		/* Copy the result to output */
-		memcpy(oname->name, workbuf, iname->len);
-		res = iname->len;
-	}
-	kunmap(ctx->workpage);
 	ablkcipher_request_free(req);
 	if (res < 0) {
 		printk_ratelimited(
@@ -198,306 +199,57 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
 	return oname->len;
 }
 
+static const char *lookup_table =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+
 /**
  * ext4_fname_encode_digest() -
  *
  * Encodes the input digest using characters from the set [a-zA-Z0-9_+].
  * The encoded string is roughly 4/3 times the size of the input string.
  */
-int ext4_fname_encode_digest(char *dst, char *src, u32 len)
+static int digest_encode(const char *src, int len, char *dst)
 {
-	static const char *lookup_table =
-		"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_+";
-	u32 current_chunk, num_chunks, i;
-	char tmp_buf[3];
-	u32 c0, c1, c2, c3;
-
-	current_chunk = 0;
-	num_chunks = len/3;
-	for (i = 0; i < num_chunks; i++) {
-		c0 = src[3*i] & 0x3f;
-		c1 = (((src[3*i]>>6)&0x3) | ((src[3*i+1] & 0xf)<<2)) & 0x3f;
-		c2 = (((src[3*i+1]>>4)&0xf) | ((src[3*i+2] & 0x3)<<4)) & 0x3f;
-		c3 = (src[3*i+2]>>2) & 0x3f;
-		dst[4*i] = lookup_table[c0];
-		dst[4*i+1] = lookup_table[c1];
-		dst[4*i+2] = lookup_table[c2];
-		dst[4*i+3] = lookup_table[c3];
-	}
-	if (i*3 < len) {
-		memset(tmp_buf, 0, 3);
-		memcpy(tmp_buf, &src[3*i], len-3*i);
-		c0 = tmp_buf[0] & 0x3f;
-		c1 = (((tmp_buf[0]>>6)&0x3) | ((tmp_buf[1] & 0xf)<<2)) & 0x3f;
-		c2 = (((tmp_buf[1]>>4)&0xf) | ((tmp_buf[2] & 0x3)<<4)) & 0x3f;
-		c3 = (tmp_buf[2]>>2) & 0x3f;
-		dst[4*i] = lookup_table[c0];
-		dst[4*i+1] = lookup_table[c1];
-		dst[4*i+2] = lookup_table[c2];
-		dst[4*i+3] = lookup_table[c3];
+	int i = 0, bits = 0, ac = 0;
+	char *cp = dst;
+
+	while (i < len) {
+		ac += (((unsigned char) src[i]) << bits);
+		bits += 8;
+		do {
+			*cp++ = lookup_table[ac & 0x3f];
+			ac >>= 6;
+			bits -= 6;
+		} while (bits >= 6);
 		i++;
 	}
-	return (i * 4);
-}
-
-/**
- * ext4_fname_hash() -
- *
- * This function computes the hash of the input filename, and sets the output
- * buffer to the *encoded* digest.  It returns the length of the digest as its
- * return value.  Errors are returned as negative numbers.  We trust the caller
- * to allocate sufficient memory to oname string.
- */
-static int ext4_fname_hash(struct ext4_fname_crypto_ctx *ctx,
-			   const struct ext4_str *iname,
-			   struct ext4_str *oname)
-{
-	struct scatterlist sg;
-	struct hash_desc desc = {
-		.tfm = (struct crypto_hash *)ctx->htfm,
-		.flags = CRYPTO_TFM_REQ_MAY_SLEEP
-	};
-	int res = 0;
-
-	if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
-		res = ext4_fname_encode_digest(oname->name, iname->name,
-					       iname->len);
-		oname->len = res;
-		return res;
-	}
-
-	sg_init_one(&sg, iname->name, iname->len);
-	res = crypto_hash_init(&desc);
-	if (res) {
-		printk(KERN_ERR
-		       "%s: Error initializing crypto hash; res = [%d]\n",
-		       __func__, res);
-		goto out;
-	}
-	res = crypto_hash_update(&desc, &sg, iname->len);
-	if (res) {
-		printk(KERN_ERR
-		       "%s: Error updating crypto hash; res = [%d]\n",
-		       __func__, res);
-		goto out;
-	}
-	res = crypto_hash_final(&desc,
-		&oname->name[EXT4_FNAME_CRYPTO_DIGEST_SIZE]);
-	if (res) {
-		printk(KERN_ERR
-		       "%s: Error finalizing crypto hash; res = [%d]\n",
-		       __func__, res);
-		goto out;
-	}
-	/* Encode the digest as a printable string--this will increase the
-	 * size of the digest */
-	oname->name[0] = 'I';
-	res = ext4_fname_encode_digest(oname->name+1,
-		&oname->name[EXT4_FNAME_CRYPTO_DIGEST_SIZE],
-		EXT4_FNAME_CRYPTO_DIGEST_SIZE) + 1;
-	oname->len = res;
-out:
-	return res;
-}
-
-/**
- * ext4_free_fname_crypto_ctx() -
- *
- * Frees up a crypto context.
- */
-void ext4_free_fname_crypto_ctx(struct ext4_fname_crypto_ctx *ctx)
-{
-	if (ctx == NULL || IS_ERR(ctx))
-		return;
-
-	if (ctx->ctfm && !IS_ERR(ctx->ctfm))
-		crypto_free_ablkcipher(ctx->ctfm);
-	if (ctx->htfm && !IS_ERR(ctx->htfm))
-		crypto_free_hash(ctx->htfm);
-	if (ctx->workpage && !IS_ERR(ctx->workpage))
-		__free_page(ctx->workpage);
-	kfree(ctx);
+	if (bits)
+		*cp++ = lookup_table[ac & 0x3f];
+	return cp - dst;
 }
 
-/**
- * ext4_put_fname_crypto_ctx() -
- *
- * Return: The crypto context onto free list. If the free list is above a
- * threshold, completely frees up the context, and returns the memory.
- *
- * TODO: Currently we directly free the crypto context. Eventually we should
- * add code it to return to free list. Such an approach will increase
- * efficiency of directory lookup.
- */
-void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx)
+static int digest_decode(const char *src, int len, char *dst)
 {
-	if (*ctx == NULL || IS_ERR(*ctx))
-		return;
-	ext4_free_fname_crypto_ctx(*ctx);
-	*ctx = NULL;
-}
-
-/**
- * ext4_search_fname_crypto_ctx() -
- */
-static struct ext4_fname_crypto_ctx *ext4_search_fname_crypto_ctx(
-		const struct ext4_encryption_key *key)
-{
-	return NULL;
-}
-
-/**
- * ext4_alloc_fname_crypto_ctx() -
- */
-struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
-	const struct ext4_encryption_key *key)
-{
-	struct ext4_fname_crypto_ctx *ctx;
-
-	ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS);
-	if (ctx == NULL)
-		return ERR_PTR(-ENOMEM);
-	if (key->mode == EXT4_ENCRYPTION_MODE_INVALID) {
-		/* This will automatically set key mode to invalid
-		 * As enum for ENCRYPTION_MODE_INVALID is zero */
-		memset(&ctx->key, 0, sizeof(ctx->key));
-	} else {
-		memcpy(&ctx->key, key, sizeof(struct ext4_encryption_key));
-	}
-	ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == key->mode)
-		? 0 : 1;
-	ctx->ctfm_key_is_ready = 0;
-	ctx->ctfm = NULL;
-	ctx->htfm = NULL;
-	ctx->workpage = NULL;
-	return ctx;
-}
-
-/**
- * ext4_get_fname_crypto_ctx() -
- *
- * Allocates a free crypto context and initializes it to hold
- * the crypto material for the inode.
- *
- * Return: NULL if not encrypted. Error value on error. Valid pointer otherwise.
- */
-struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
-	struct inode *inode, u32 max_ciphertext_len)
-{
-	struct ext4_fname_crypto_ctx *ctx;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	int res;
-
-	/* Check if the crypto policy is set on the inode */
-	res = ext4_encrypted_inode(inode);
-	if (res == 0)
-		return NULL;
-
-	if (!ext4_has_encryption_key(inode))
-		ext4_generate_encryption_key(inode);
-
-	/* Get a crypto context based on the key.
-	 * A new context is allocated if no context matches the requested key.
-	 */
-	ctx = ext4_search_fname_crypto_ctx(&(ei->i_encryption_key));
-	if (ctx == NULL)
-		ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_encryption_key));
-	if (IS_ERR(ctx))
-		return ctx;
-
-	if (ctx->has_valid_key) {
-		if (ctx->key.mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
-			printk_once(KERN_WARNING
-				    "ext4: unsupported key mode %d\n",
-				    ctx->key.mode);
-			return ERR_PTR(-ENOKEY);
-		}
-
-		/* As a first cut, we will allocate new tfm in every call.
-		 * later, we will keep the tfm around, in case the key gets
-		 * re-used */
-		if (ctx->ctfm == NULL) {
-			ctx->ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))",
-					0, 0);
-		}
-		if (IS_ERR(ctx->ctfm)) {
-			res = PTR_ERR(ctx->ctfm);
-			printk(
-			    KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
-			    __func__, res);
-			ctx->ctfm = NULL;
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(res);
-		}
-		if (ctx->ctfm == NULL) {
-			printk(
-			    KERN_DEBUG "%s: could not allocate crypto tfm\n",
-			    __func__);
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(-ENOMEM);
-		}
-		if (ctx->workpage == NULL)
-			ctx->workpage = alloc_page(GFP_NOFS);
-		if (IS_ERR(ctx->workpage)) {
-			res = PTR_ERR(ctx->workpage);
-			printk(
-			    KERN_DEBUG "%s: error (%d) allocating work page\n",
-			    __func__, res);
-			ctx->workpage = NULL;
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(res);
+	int i = 0, bits = 0, ac = 0;
+	const char *p;
+	char *cp = dst;
+
+	while (i < len) {
+		p = strchr(lookup_table, src[i]);
+		if (p == NULL || src[i] == 0)
+			return -2;
+		ac += (p - lookup_table) << bits;
+		bits += 6;
+		if (bits >= 8) {
+			*cp++ = ac & 0xff;
+			ac >>= 8;
+			bits -= 8;
 		}
-		if (ctx->workpage == NULL) {
-			printk(
-			    KERN_DEBUG "%s: could not allocate work page\n",
-			    __func__);
-			ext4_put_fname_crypto_ctx(&ctx);
-			return ERR_PTR(-ENOMEM);
-		}
-		ctx->lim = max_ciphertext_len;
-		crypto_ablkcipher_clear_flags(ctx->ctfm, ~0);
-		crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctx->ctfm),
-			CRYPTO_TFM_REQ_WEAK_KEY);
-
-		/* If we are lucky, we will get a context that is already
-		 * set up with the right key. Else, we will have to
-		 * set the key */
-		if (!ctx->ctfm_key_is_ready) {
-			/* Since our crypto objectives for filename encryption
-			 * are pretty weak,
-			 * we directly use the inode master key */
-			res = crypto_ablkcipher_setkey(ctx->ctfm,
-					ctx->key.raw, ctx->key.size);
-			if (res) {
-				ext4_put_fname_crypto_ctx(&ctx);
-				return ERR_PTR(-EIO);
-			}
-			ctx->ctfm_key_is_ready = 1;
-		} else {
-			/* In the current implementation, key should never be
-			 * marked "ready" for a context that has just been
-			 * allocated. So we should never reach here */
-			 BUG();
-		}
-	}
-	if (ctx->htfm == NULL)
-		ctx->htfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(ctx->htfm)) {
-		res = PTR_ERR(ctx->htfm);
-		printk(KERN_DEBUG "%s: error (%d) allocating hash tfm\n",
-			__func__, res);
-		ctx->htfm = NULL;
-		ext4_put_fname_crypto_ctx(&ctx);
-		return ERR_PTR(res);
-	}
-	if (ctx->htfm == NULL) {
-		printk(KERN_DEBUG "%s: could not allocate hash tfm\n",
-				__func__);
-		ext4_put_fname_crypto_ctx(&ctx);
-		return ERR_PTR(-ENOMEM);
+		i++;
 	}
-
-	return ctx;
+	if (ac)
+		return -1;
+	return cp - dst;
 }
 
 /**
@@ -510,39 +262,29 @@ u32 ext4_fname_crypto_round_up(u32 size, u32 blksize)
 	return ((size+blksize-1)/blksize)*blksize;
 }
 
-/**
- * ext4_fname_crypto_namelen_on_disk() -
- */
-int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
-				      u32 namelen)
+unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen)
 {
-	u32 ciphertext_len;
-
-	if (ctx == NULL)
-		return -EIO;
-	if (!(ctx->has_valid_key))
-		return -EACCES;
-	ciphertext_len = (namelen < EXT4_CRYPTO_BLOCK_SIZE) ?
-		EXT4_CRYPTO_BLOCK_SIZE : namelen;
-	ciphertext_len = (ciphertext_len > ctx->lim)
-			? ctx->lim : ciphertext_len;
-	return (int) ciphertext_len;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+	int padding = 32;
+
+	if (ci)
+		padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
+	if (ilen < EXT4_CRYPTO_BLOCK_SIZE)
+		ilen = EXT4_CRYPTO_BLOCK_SIZE;
+	return ext4_fname_crypto_round_up(ilen, padding);
 }
 
-/**
- * ext4_fname_crypto_alloc_obuff() -
+/*
+ * ext4_fname_crypto_alloc_buffer() -
  *
  * Allocates an output buffer that is sufficient for the crypto operation
  * specified by the context and the direction.
  */
-int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_crypto_alloc_buffer(struct inode *inode,
 				   u32 ilen, struct ext4_str *crypto_str)
 {
-	unsigned int olen;
+	unsigned int olen = ext4_fname_encrypted_size(inode, ilen);
 
-	if (!ctx)
-		return -EIO;
-	olen = ext4_fname_crypto_round_up(ilen, EXT4_CRYPTO_BLOCK_SIZE);
 	crypto_str->len = olen;
 	if (olen < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2)
 		olen = EXT4_FNAME_CRYPTO_DIGEST_SIZE*2;
@@ -570,12 +312,14 @@ void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str)
 /**
  * ext4_fname_disk_to_usr() - converts a filename from disk space to user space
  */
-int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
-			   const struct ext4_str *iname,
-			   struct ext4_str *oname)
+int _ext4_fname_disk_to_usr(struct inode *inode,
+			    struct dx_hash_info *hinfo,
+			    const struct ext4_str *iname,
+			    struct ext4_str *oname)
 {
-	if (ctx == NULL)
-		return -EIO;
+	char buf[24];
+	int ret;
+
 	if (iname->len < 3) {
 		/*Check for . and .. */
 		if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') {
@@ -585,34 +329,48 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 			return oname->len;
 		}
 	}
-	if (ctx->has_valid_key)
-		return ext4_fname_decrypt(ctx, iname, oname);
-	else
-		return ext4_fname_hash(ctx, iname, oname);
+	if (EXT4_I(inode)->i_crypt_info)
+		return ext4_fname_decrypt(inode, iname, oname);
+
+	if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
+		ret = digest_encode(iname->name, iname->len, oname->name);
+		oname->len = ret;
+		return ret;
+	}
+	if (hinfo) {
+		memcpy(buf, &hinfo->hash, 4);
+		memcpy(buf+4, &hinfo->minor_hash, 4);
+	} else
+		memset(buf, 0, 8);
+	memcpy(buf + 8, iname->name + iname->len - 16, 16);
+	oname->name[0] = '_';
+	ret = digest_encode(buf, 24, oname->name+1);
+	oname->len = ret + 1;
+	return ret + 1;
 }
 
-int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_disk_to_usr(struct inode *inode,
+			   struct dx_hash_info *hinfo,
 			   const struct ext4_dir_entry_2 *de,
 			   struct ext4_str *oname)
 {
 	struct ext4_str iname = {.name = (unsigned char *) de->name,
 				 .len = de->name_len };
 
-	return _ext4_fname_disk_to_usr(ctx, &iname, oname);
+	return _ext4_fname_disk_to_usr(inode, hinfo, &iname, oname);
 }
 
 
 /**
  * ext4_fname_usr_to_disk() - converts a filename from user space to disk space
  */
-int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_usr_to_disk(struct inode *inode,
 			   const struct qstr *iname,
 			   struct ext4_str *oname)
 {
 	int res;
+	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
 
-	if (ctx == NULL)
-		return -EIO;
 	if (iname->len < 3) {
 		/*Check for . and .. */
 		if (iname->name[0] == '.' &&
@@ -623,8 +381,8 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
 			return oname->len;
 		}
 	}
-	if (ctx->has_valid_key) {
-		res = ext4_fname_encrypt(ctx, iname, oname);
+	if (ci) {
+		res = ext4_fname_encrypt(inode, iname, oname);
 		return res;
 	}
 	/* Without a proper key, a user is not allowed to modify the filenames
@@ -633,77 +391,79 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
 	return -EACCES;
 }
 
-/*
- * Calculate the htree hash from a filename from user space
- */
-int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
-			    const struct qstr *iname,
-			    struct dx_hash_info *hinfo)
+int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
+			      int lookup, struct ext4_filename *fname)
 {
-	struct ext4_str tmp, tmp2;
-	int ret = 0;
+	struct ext4_crypt_info *ci;
+	int ret = 0, bigname = 0;
+
+	memset(fname, 0, sizeof(struct ext4_filename));
+	fname->usr_fname = iname;
 
-	if (!ctx || !ctx->has_valid_key ||
+	if (!ext4_encrypted_inode(dir) ||
 	    ((iname->name[0] == '.') &&
 	     ((iname->len == 1) ||
 	      ((iname->name[1] == '.') && (iname->len == 2))))) {
-		ext4fs_dirhash(iname->name, iname->len, hinfo);
+		fname->disk_name.name = (unsigned char *) iname->name;
+		fname->disk_name.len = iname->len;
 		return 0;
 	}
-
-	/* First encrypt the plaintext name */
-	ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len, &tmp);
-	if (ret < 0)
+	ret = ext4_get_encryption_info(dir);
+	if (ret)
 		return ret;
-
-	ret = ext4_fname_encrypt(ctx, iname, &tmp);
-	if (ret < 0)
-		goto out;
-
-	tmp2.len = (4 * ((EXT4_FNAME_CRYPTO_DIGEST_SIZE + 2) / 3)) + 1;
-	tmp2.name = kmalloc(tmp2.len + 1, GFP_KERNEL);
-	if (tmp2.name == NULL) {
-		ret = -ENOMEM;
-		goto out;
+	ci = EXT4_I(dir)->i_crypt_info;
+	if (ci) {
+		ret = ext4_fname_crypto_alloc_buffer(dir, iname->len,
+						     &fname->crypto_buf);
+		if (ret < 0)
+			return ret;
+		ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf);
+		if (ret < 0)
+			goto errout;
+		fname->disk_name.name = fname->crypto_buf.name;
+		fname->disk_name.len = fname->crypto_buf.len;
+		return 0;
 	}
+	if (!lookup)
+		return -EACCES;
 
-	ret = ext4_fname_hash(ctx, &tmp, &tmp2);
-	if (ret > 0)
-		ext4fs_dirhash(tmp2.name, tmp2.len, hinfo);
-	ext4_fname_crypto_free_buffer(&tmp2);
-out:
-	ext4_fname_crypto_free_buffer(&tmp);
+	/* We don't have the key and we are doing a lookup; decode the
+	 * user-supplied name
+	 */
+	if (iname->name[0] == '_')
+		bigname = 1;
+	if ((bigname && (iname->len != 33)) ||
+	    (!bigname && (iname->len > 43)))
+		return -ENOENT;
+
+	fname->crypto_buf.name = kmalloc(32, GFP_KERNEL);
+	if (fname->crypto_buf.name == NULL)
+		return -ENOMEM;
+	ret = digest_decode(iname->name + bigname, iname->len - bigname,
+			    fname->crypto_buf.name);
+	if (ret < 0) {
+		ret = -ENOENT;
+		goto errout;
+	}
+	fname->crypto_buf.len = ret;
+	if (bigname) {
+		memcpy(&fname->hinfo.hash, fname->crypto_buf.name, 4);
+		memcpy(&fname->hinfo.minor_hash, fname->crypto_buf.name + 4, 4);
+	} else {
+		fname->disk_name.name = fname->crypto_buf.name;
+		fname->disk_name.len = fname->crypto_buf.len;
+	}
+	return 0;
+errout:
+	kfree(fname->crypto_buf.name);
+	fname->crypto_buf.name = NULL;
 	return ret;
 }
 
-/**
- * ext4_fname_disk_to_htree() - converts a filename from disk space to htree-access string
- */
-int ext4_fname_disk_to_hash(struct ext4_fname_crypto_ctx *ctx,
-			    const struct ext4_dir_entry_2 *de,
-			    struct dx_hash_info *hinfo)
+void ext4_fname_free_filename(struct ext4_filename *fname)
 {
-	struct ext4_str iname = {.name = (unsigned char *) de->name,
-				 .len = de->name_len};
-	struct ext4_str tmp;
-	int ret;
-
-	if (!ctx ||
-	    ((iname.name[0] == '.') &&
-	     ((iname.len == 1) ||
-	      ((iname.name[1] == '.') && (iname.len == 2))))) {
-		ext4fs_dirhash(iname.name, iname.len, hinfo);
-		return 0;
-	}
-
-	tmp.len = (4 * ((EXT4_FNAME_CRYPTO_DIGEST_SIZE + 2) / 3)) + 1;
-	tmp.name = kmalloc(tmp.len + 1, GFP_KERNEL);
-	if (tmp.name == NULL)
-		return -ENOMEM;
-
-	ret = ext4_fname_hash(ctx, &iname, &tmp);
-	if (ret > 0)
-		ext4fs_dirhash(tmp.name, tmp.len, hinfo);
-	ext4_fname_crypto_free_buffer(&tmp);
-	return ret;
+	kfree(fname->crypto_buf.name);
+	fname->crypto_buf.name = NULL;
+	fname->usr_fname = NULL;
+	fname->disk_name.name = NULL;
 }