Some miscellaneous bug fixes and some final on-disk and ABI changes

for ext4 encryption which provide better security and performance.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQEcBAABCAAGBQJVRsVDAAoJEPL5WVaVDYGj/UUIAI6zLGhq3I8uQLZQC22Ew2Ph
 TPj6eABDuTrB/7QpAu21Dk59N70MQpsBTES6yLWWLf/eHp0gsH7gCNY/C9185vOh
 tQjzw18hRH2IfPftOBrjDlPGbbBD8Gu9jAmpm5kKKOtBuSVbKQ4GeN6BTECkgwlg
 U5EJHJJ5Ahl4MalODFreOE5ZrVC7FWGEpc1y/MquQ0qcGSGlNd35leK5FE2bfHWZ
 M1IJfXH5RRVPUBp26uNvzEg0TtpqkigmCJUT6gOVLfSYBw+lYEbGl4lCflrJmbgt
 8EZh3Q0plsDbNhMzqSvOE4RvsOZ28oMjRNbzxkAaoz/FlatWX2hrfAoI2nqRrKg=
 =Unbp
 -----END PGP SIGNATURE-----

Merge tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Some miscellaneous bug fixes and some final on-disk and ABI changes
  for ext4 encryption which provide better security and performance"

* tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix growing of tiny filesystems
  ext4: move check under lock scope to close a race.
  ext4: fix data corruption caused by unwritten and delayed extents
  ext4 crypto: remove duplicated encryption mode definitions
  ext4 crypto: do not select from EXT4_FS_ENCRYPTION
  ext4 crypto: add padding to filenames before encrypting
  ext4 crypto: simplify and speed up filename encryption

fs/ext4/Kconfig

@@ -64,8 +64,8 @@ config EXT4_FS_SECURITY
 	  If you are not using a security module that requires using
 	  extended attributes for file security labels, say N.
 
-config EXT4_FS_ENCRYPTION
+config EXT4_ENCRYPTION
-	bool "Ext4 Encryption"
+	tristate "Ext4 Encryption"
 	depends on EXT4_FS
 	select CRYPTO_AES
 	select CRYPTO_CBC
@@ -81,6 +81,11 @@ config EXT4_FS_ENCRYPTION
 	  efficient since it avoids caching the encrypted and
 	  decrypted pages in the page cache.
 
+config EXT4_FS_ENCRYPTION
+	bool
+	default y
+	depends on EXT4_ENCRYPTION
+
 config EXT4_DEBUG
 	bool "EXT4 debugging support"
 	depends on EXT4_FS

fs/ext4/crypto_fname.c

@@ -66,6 +66,7 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
 	int res = 0;
 	char iv[EXT4_CRYPTO_BLOCK_SIZE];
 	struct scatterlist sg[1];
+	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
 	char *workbuf;
 
 	if (iname->len <= 0 || iname->len > ctx->lim)
@@ -73,6 +74,7 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
 
 	ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
 		EXT4_CRYPTO_BLOCK_SIZE : iname->len;
+	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
 	ciphertext_len = (ciphertext_len > ctx->lim)
 			? ctx->lim : ciphertext_len;
 
@@ -101,7 +103,7 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
 	/* 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);
+	ablkcipher_request_set_crypt(req, sg, sg, ciphertext_len, iv);
 	res = crypto_ablkcipher_encrypt(req);
 	if (res == -EINPROGRESS || res == -EBUSY) {
 		BUG_ON(req->base.data != &ecr);
@@ -198,106 +200,57 @@ 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 =
+	int i = 0, bits = 0, ac = 0;
-		"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_+";
+	char *cp = dst;
-	u32 current_chunk, num_chunks, i;
-	char tmp_buf[3];
-	u32 c0, c1, c2, c3;
 
-	current_chunk = 0;
+	while (i < len) {
-	num_chunks = len/3;
+		ac += (((unsigned char) src[i]) << bits);
-	for (i = 0; i < num_chunks; i++) {
+		bits += 8;
-		c0 = src[3*i] & 0x3f;
+		do {
-		c1 = (((src[3*i]>>6)&0x3) | ((src[3*i+1] & 0xf)<<2)) & 0x3f;
+			*cp++ = lookup_table[ac & 0x3f];
-		c2 = (((src[3*i+1]>>4)&0xf) | ((src[3*i+2] & 0x3)<<4)) & 0x3f;
+			ac >>= 6;
-		c3 = (src[3*i+2]>>2) & 0x3f;
+			bits -= 6;
-		dst[4*i] = lookup_table[c0];
+		} while (bits >= 6);
-		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];
 		i++;
 	}
-	return (i * 4);
+	if (bits)
+		*cp++ = lookup_table[ac & 0x3f];
+	return cp - dst;
 }
 
-/**
+static int digest_decode(const char *src, int len, char *dst)
- * 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;
+	int i = 0, bits = 0, ac = 0;
-	struct hash_desc desc = {
+	const char *p;
-		.tfm = (struct crypto_hash *)ctx->htfm,
+	char *cp = dst;
-		.flags = CRYPTO_TFM_REQ_MAY_SLEEP
-	};
-	int res = 0;
 
-	if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
+	while (i < len) {
-		res = ext4_fname_encode_digest(oname->name, iname->name,
+		p = strchr(lookup_table, src[i]);
-					       iname->len);
+		if (p == NULL || src[i] == 0)
-		oname->len = res;
+			return -2;
-		return res;
+		ac += (p - lookup_table) << bits;
+		bits += 6;
+		if (bits >= 8) {
+			*cp++ = ac & 0xff;
+			ac >>= 8;
+			bits -= 8;
+		}
+		i++;
 	}
-
+	if (ac)
-	sg_init_one(&sg, iname->name, iname->len);
+		return -1;
-	res = crypto_hash_init(&desc);
+	return cp - dst;
-	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;
 }
 
 /**
@@ -405,6 +358,7 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
 	if (IS_ERR(ctx))
 		return ctx;
 
+	ctx->flags = ei->i_crypt_policy_flags;
 	if (ctx->has_valid_key) {
 		if (ctx->key.mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
 			printk_once(KERN_WARNING
@@ -517,6 +471,7 @@ int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
 				      u32 namelen)
 {
 	u32 ciphertext_len;
+	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
 
 	if (ctx == NULL)
 		return -EIO;
@@ -524,6 +479,7 @@ int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
 		return -EACCES;
 	ciphertext_len = (namelen < EXT4_CRYPTO_BLOCK_SIZE) ?
 		EXT4_CRYPTO_BLOCK_SIZE : namelen;
+	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
 	ciphertext_len = (ciphertext_len > ctx->lim)
 			? ctx->lim : ciphertext_len;
 	return (int) ciphertext_len;
@@ -539,10 +495,13 @@ int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
 				   u32 ilen, struct ext4_str *crypto_str)
 {
 	unsigned int olen;
+	int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
 
 	if (!ctx)
 		return -EIO;
-	olen = ext4_fname_crypto_round_up(ilen, EXT4_CRYPTO_BLOCK_SIZE);
+	if (padding < EXT4_CRYPTO_BLOCK_SIZE)
+		padding = EXT4_CRYPTO_BLOCK_SIZE;
+	olen = ext4_fname_crypto_round_up(ilen, padding);
 	crypto_str->len = olen;
 	if (olen < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2)
 		olen = EXT4_FNAME_CRYPTO_DIGEST_SIZE*2;
@@ -571,9 +530,13 @@ 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 dx_hash_info *hinfo,
-			   struct ext4_str *oname)
+			    const struct ext4_str *iname,
+			    struct ext4_str *oname)
 {
+	char buf[24];
+	int ret;
+
 	if (ctx == NULL)
 		return -EIO;
 	if (iname->len < 3) {
@@ -587,18 +550,33 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
 	}
 	if (ctx->has_valid_key)
 		return ext4_fname_decrypt(ctx, iname, oname);
-	else
+
-		return ext4_fname_hash(ctx, 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,
+			   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(ctx, hinfo, &iname, oname);
 }
 
 
@@ -640,10 +618,11 @@ int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
 			    const struct qstr *iname,
 			    struct dx_hash_info *hinfo)
 {
-	struct ext4_str tmp, tmp2;
+	struct ext4_str tmp;
 	int ret = 0;
+	char buf[EXT4_FNAME_CRYPTO_DIGEST_SIZE+1];
 
-	if (!ctx || !ctx->has_valid_key ||
+	if (!ctx ||
 	    ((iname->name[0] == '.') &&
 	     ((iname->len == 1) ||
 	      ((iname->name[1] == '.') && (iname->len == 2))))) {
@@ -651,59 +630,90 @@ int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
 		return 0;
 	}
 
+	if (!ctx->has_valid_key && iname->name[0] == '_') {
+		if (iname->len != 33)
+			return -ENOENT;
+		ret = digest_decode(iname->name+1, iname->len, buf);
+		if (ret != 24)
+			return -ENOENT;
+		memcpy(&hinfo->hash, buf, 4);
+		memcpy(&hinfo->minor_hash, buf + 4, 4);
+		return 0;
+	}
+
+	if (!ctx->has_valid_key && iname->name[0] != '_') {
+		if (iname->len > 43)
+			return -ENOENT;
+		ret = digest_decode(iname->name, iname->len, buf);
+		ext4fs_dirhash(buf, ret, hinfo);
+		return 0;
+	}
+
 	/* First encrypt the plaintext name */
 	ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len, &tmp);
 	if (ret < 0)
 		return ret;
 
 	ret = ext4_fname_encrypt(ctx, iname, &tmp);
-	if (ret < 0)
+	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;
-	}
-
-	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);
-	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)
-{
-	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);
+		ret = 0;
+	}
+
 	ext4_fname_crypto_free_buffer(&tmp);
 	return ret;
 }
+
+int ext4_fname_match(struct ext4_fname_crypto_ctx *ctx, struct ext4_str *cstr,
+		     int len, const char * const name,
+		     struct ext4_dir_entry_2 *de)
+{
+	int ret = -ENOENT;
+	int bigname = (*name == '_');
+
+	if (ctx->has_valid_key) {
+		if (cstr->name == NULL) {
+			struct qstr istr;
+
+			ret = ext4_fname_crypto_alloc_buffer(ctx, len, cstr);
+			if (ret < 0)
+				goto errout;
+			istr.name = name;
+			istr.len = len;
+			ret = ext4_fname_encrypt(ctx, &istr, cstr);
+			if (ret < 0)
+				goto errout;
+		}
+	} else {
+		if (cstr->name == NULL) {
+			cstr->name = kmalloc(32, GFP_KERNEL);
+			if (cstr->name == NULL)
+				return -ENOMEM;
+			if ((bigname && (len != 33)) ||
+			    (!bigname && (len > 43)))
+				goto errout;
+			ret = digest_decode(name+bigname, len-bigname,
+					    cstr->name);
+			if (ret < 0) {
+				ret = -ENOENT;
+				goto errout;
+			}
+			cstr->len = ret;
+		}
+		if (bigname) {
+			if (de->name_len < 16)
+				return 0;
+			ret = memcmp(de->name + de->name_len - 16,
+				     cstr->name + 8, 16);
+			return (ret == 0) ? 1 : 0;
+		}
+	}
+	if (de->name_len != cstr->len)
+		return 0;
+	ret = memcmp(de->name, cstr->name, cstr->len);
+	return (ret == 0) ? 1 : 0;
+errout:
+	kfree(cstr->name);
+	cstr->name = NULL;
+	return ret;
+}

fs/ext4/crypto_key.c

@@ -110,6 +110,7 @@ int ext4_generate_encryption_key(struct inode *inode)
 	}
 	res = 0;
 
+	ei->i_crypt_policy_flags = ctx.flags;
 	if (S_ISREG(inode->i_mode))
 		crypt_key->mode = ctx.contents_encryption_mode;
 	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))

fs/ext4/crypto_policy.c

@@ -37,6 +37,8 @@ static int ext4_is_encryption_context_consistent_with_policy(
 		return 0;
 	return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor,
 			EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
+		(ctx.flags ==
+		 policy->flags) &&
 		(ctx.contents_encryption_mode ==
 		 policy->contents_encryption_mode) &&
 		(ctx.filenames_encryption_mode ==
@@ -56,25 +58,25 @@ static int ext4_create_encryption_context_from_policy(
 		printk(KERN_WARNING
 		       "%s: Invalid contents encryption mode %d\n", __func__,
 			policy->contents_encryption_mode);
-		res = -EINVAL;
+		return -EINVAL;
-		goto out;
 	}
 	if (!ext4_valid_filenames_enc_mode(policy->filenames_encryption_mode)) {
 		printk(KERN_WARNING
 		       "%s: Invalid filenames encryption mode %d\n", __func__,
 			policy->filenames_encryption_mode);
-		res = -EINVAL;
+		return -EINVAL;
-		goto out;
 	}
+	if (policy->flags & ~EXT4_POLICY_FLAGS_VALID)
+		return -EINVAL;
 	ctx.contents_encryption_mode = policy->contents_encryption_mode;
 	ctx.filenames_encryption_mode = policy->filenames_encryption_mode;
+	ctx.flags = policy->flags;
 	BUILD_BUG_ON(sizeof(ctx.nonce) != EXT4_KEY_DERIVATION_NONCE_SIZE);
 	get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
 
 	res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
 			     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
 			     sizeof(ctx), 0);
-out:
 	if (!res)
 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
 	return res;
@@ -115,6 +117,7 @@ int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
 	policy->version = 0;
 	policy->contents_encryption_mode = ctx.contents_encryption_mode;
 	policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
+	policy->flags = ctx.flags;
 	memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
 	       EXT4_KEY_DESCRIPTOR_SIZE);
 	return 0;
@@ -176,6 +179,7 @@ int ext4_inherit_context(struct inode *parent, struct inode *child)
 				EXT4_ENCRYPTION_MODE_AES_256_XTS;
 			ctx.filenames_encryption_mode =
 				EXT4_ENCRYPTION_MODE_AES_256_CTS;
+			ctx.flags = 0;
 			memset(ctx.master_key_descriptor, 0x42,
 			       EXT4_KEY_DESCRIPTOR_SIZE);
 			res = 0;

fs/ext4/dir.c

@@ -249,7 +249,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 				} else {
 					/* Directory is encrypted */
 					err = ext4_fname_disk_to_usr(enc_ctx,
-							de, &fname_crypto_str);
+						NULL, de, &fname_crypto_str);
 					if (err < 0)
 						goto errout;
 					if (!dir_emit(ctx,

fs/ext4/ext4.h

@@ -911,6 +911,7 @@ struct ext4_inode_info {
 
 	/* on-disk additional length */
 	__u16 i_extra_isize;
+	char i_crypt_policy_flags;
 
 	/* Indicate the inline data space. */
 	u16 i_inline_off;
@@ -1066,12 +1067,6 @@ extern void ext4_set_bits(void *bm, int cur, int len);
 /* Metadata checksum algorithm codes */
 #define EXT4_CRC32C_CHKSUM		1
 
-/* Encryption algorithms */
-#define EXT4_ENCRYPTION_MODE_INVALID		0
-#define EXT4_ENCRYPTION_MODE_AES_256_XTS	1
-#define EXT4_ENCRYPTION_MODE_AES_256_GCM	2
-#define EXT4_ENCRYPTION_MODE_AES_256_CBC	3
-
 /*
  * Structure of the super block
  */
@@ -2093,9 +2088,11 @@ u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
 int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
 				   u32 ilen, struct ext4_str *crypto_str);
 int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+			    struct dx_hash_info *hinfo,
 			    const struct ext4_str *iname,
 			    struct ext4_str *oname);
 int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+			   struct dx_hash_info *hinfo,
 			   const struct ext4_dir_entry_2 *de,
 			   struct ext4_str *oname);
 int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
@@ -2104,11 +2101,12 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
 int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
 			   const struct qstr *iname,
 			   struct dx_hash_info *hinfo);
-int ext4_fname_disk_to_hash(struct ext4_fname_crypto_ctx *ctx,
-			    const struct ext4_dir_entry_2 *de,
-			    struct dx_hash_info *hinfo);
 int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
 				      u32 namelen);
+int ext4_fname_match(struct ext4_fname_crypto_ctx *ctx, struct ext4_str *cstr,
+		     int len, const char * const name,
+		     struct ext4_dir_entry_2 *de);
+
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx);

fs/ext4/ext4_crypto.h

@@ -20,12 +20,20 @@ struct ext4_encryption_policy {
 	char version;
 	char contents_encryption_mode;
 	char filenames_encryption_mode;
+	char flags;
 	char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
 } __attribute__((__packed__));
 
 #define EXT4_ENCRYPTION_CONTEXT_FORMAT_V1 1
 #define EXT4_KEY_DERIVATION_NONCE_SIZE 16
 
+#define EXT4_POLICY_FLAGS_PAD_4		0x00
+#define EXT4_POLICY_FLAGS_PAD_8		0x01
+#define EXT4_POLICY_FLAGS_PAD_16	0x02
+#define EXT4_POLICY_FLAGS_PAD_32	0x03
+#define EXT4_POLICY_FLAGS_PAD_MASK	0x03
+#define EXT4_POLICY_FLAGS_VALID		0x03
+
 /**
  * Encryption context for inode
  *
@@ -41,7 +49,7 @@ struct ext4_encryption_context {
 	char format;
 	char contents_encryption_mode;
 	char filenames_encryption_mode;
-	char reserved;
+	char flags;
 	char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
 	char nonce[EXT4_KEY_DERIVATION_NONCE_SIZE];
 } __attribute__((__packed__));
@@ -120,6 +128,7 @@ struct ext4_fname_crypto_ctx {
 	struct crypto_hash *htfm;
 	struct page *workpage;
 	struct ext4_encryption_key key;
+	unsigned flags : 8;
 	unsigned has_valid_key : 1;
 	unsigned ctfm_key_is_ready : 1;
 };

fs/ext4/extents.c

@@ -4927,13 +4927,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	if (ret)
 		return ret;
 
-	/*
-	 * currently supporting (pre)allocate mode for extent-based
-	 * files _only_
-	 */
-	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-		return -EOPNOTSUPP;
-
 	if (mode & FALLOC_FL_COLLAPSE_RANGE)
 		return ext4_collapse_range(inode, offset, len);
 
@@ -4955,6 +4948,14 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 
 	mutex_lock(&inode->i_mutex);
 
+	/*
+	 * We only support preallocation for extent-based files only
+	 */
+	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 	     offset + len > i_size_read(inode)) {
 		new_size = offset + len;

fs/ext4/extents_status.c

@@ -703,6 +703,14 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 
 	BUG_ON(end < lblk);
 
+	if ((status & EXTENT_STATUS_DELAYED) &&
+	    (status & EXTENT_STATUS_WRITTEN)) {
+		ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
+				" delayed and written which can potentially "
+				" cause data loss.\n", lblk, len);
+		WARN_ON(1);
+	}
+
 	newes.es_lblk = lblk;
 	newes.es_len = len;
 	ext4_es_store_pblock_status(&newes, pblk, status);

fs/ext4/inode.c

@@ -531,6 +531,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
 				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
 		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
+		    !(status & EXTENT_STATUS_WRITTEN) &&
 		    ext4_find_delalloc_range(inode, map->m_lblk,
 					     map->m_lblk + map->m_len - 1))
 			status |= EXTENT_STATUS_DELAYED;
@@ -635,6 +636,7 @@ found:
 		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
 				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
 		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
+		    !(status & EXTENT_STATUS_WRITTEN) &&
 		    ext4_find_delalloc_range(inode, map->m_lblk,
 					     map->m_lblk + map->m_len - 1))
 			status |= EXTENT_STATUS_DELAYED;

fs/ext4/namei.c

@@ -640,7 +640,7 @@ static struct stats dx_show_leaf(struct inode *dir,
 						ext4_put_fname_crypto_ctx(&ctx);
 						ctx = NULL;
 					}
-					res = ext4_fname_disk_to_usr(ctx, de,
+					res = ext4_fname_disk_to_usr(ctx, NULL, de,
 							&fname_crypto_str);
 					if (res < 0) {
 						printk(KERN_WARNING "Error "
@@ -653,15 +653,8 @@ static struct stats dx_show_leaf(struct inode *dir,
 						name = fname_crypto_str.name;
 						len = fname_crypto_str.len;
 					}
-					res = ext4_fname_disk_to_hash(ctx, de,
+					ext4fs_dirhash(de->name, de->name_len,
-								      &h);
+						       &h);
-					if (res < 0) {
-						printk(KERN_WARNING "Error "
-							"converting filename "
-							"from disk to htree"
-							"\n");
-						h.hash = 0xDEADBEEF;
-					}
 					printk("%*.s:(E)%x.%u ", len, name,
 					       h.hash, (unsigned) ((char *) de
 								   - base));
@@ -1008,15 +1001,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 			/* silently ignore the rest of the block */
 			break;
 		}
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-		err = ext4_fname_disk_to_hash(ctx, de, hinfo);
-		if (err < 0) {
-			count = err;
-			goto errout;
-		}
-#else
 		ext4fs_dirhash(de->name, de->name_len, hinfo);
-#endif
 		if ((hinfo->hash < start_hash) ||
 		    ((hinfo->hash == start_hash) &&
 		     (hinfo->minor_hash < start_minor_hash)))
@@ -1032,7 +1017,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 				   &tmp_str);
 		} else {
 			/* Directory is encrypted */
-			err = ext4_fname_disk_to_usr(ctx, de,
+			err = ext4_fname_disk_to_usr(ctx, hinfo, de,
 						     &fname_crypto_str);
 			if (err < 0) {
 				count = err;
@@ -1193,26 +1178,10 @@ static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 	int count = 0;
 	char *base = (char *) de;
 	struct dx_hash_info h = *hinfo;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	struct ext4_fname_crypto_ctx *ctx = NULL;
-	int err;
-
-	ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
-	if (IS_ERR(ctx))
-		return PTR_ERR(ctx);
-#endif
 
 	while ((char *) de < base + blocksize) {
 		if (de->name_len && de->inode) {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-			err = ext4_fname_disk_to_hash(ctx, de, &h);
-			if (err < 0) {
-				ext4_put_fname_crypto_ctx(&ctx);
-				return err;
-			}
-#else
 			ext4fs_dirhash(de->name, de->name_len, &h);
-#endif
 			map_tail--;
 			map_tail->hash = h.hash;
 			map_tail->offs = ((char *) de - base)>>2;
@@ -1223,9 +1192,6 @@ static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
 		/* XXX: do we need to check rec_len == 0 case? -Chris */
 		de = ext4_next_entry(de, blocksize);
 	}
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	ext4_put_fname_crypto_ctx(&ctx);
-#endif
 	return count;
 }
 
@@ -1287,16 +1253,8 @@ static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
 		return 0;
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	if (ctx) {
+	if (ctx)
-		/* Directory is encrypted */
+		return ext4_fname_match(ctx, fname_crypto_str, len, name, de);
-		res = ext4_fname_disk_to_usr(ctx, de, fname_crypto_str);
-		if (res < 0)
-			return res;
-		if (len != res)
-			return 0;
-		res = memcmp(name, fname_crypto_str->name, len);
-		return (res == 0) ? 1 : 0;
-	}
 #endif
 	if (len != de->name_len)
 		return 0;
@@ -1324,16 +1282,6 @@ int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 	if (IS_ERR(ctx))
 		return -1;
 
-	if (ctx != NULL) {
-		/* Allocate buffer to hold maximum name length */
-		res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
-						     &fname_crypto_str);
-		if (res < 0) {
-			ext4_put_fname_crypto_ctx(&ctx);
-			return -1;
-		}
-	}
-
 	de = (struct ext4_dir_entry_2 *)search_buf;
 	dlimit = search_buf + buf_size;
 	while ((char *) de < dlimit) {
@@ -1872,14 +1820,6 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 			return res;
 		}
 		reclen = EXT4_DIR_REC_LEN(res);
-
-		/* Allocate buffer to hold maximum name length */
-		res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
-						     &fname_crypto_str);
-		if (res < 0) {
-			ext4_put_fname_crypto_ctx(&ctx);
-			return -1;
-		}
 	}
 
 	de = (struct ext4_dir_entry_2 *)buf;

fs/ext4/resize.c

@@ -1432,12 +1432,15 @@ static int ext4_flex_group_add(struct super_block *sb,
 		goto exit;
 	/*
 	 * We will always be modifying at least the superblock and  GDT
-	 * block.  If we are adding a group past the last current GDT block,
+	 * blocks.  If we are adding a group past the last current GDT block,
 	 * we will also modify the inode and the dindirect block.  If we
 	 * are adding a group with superblock/GDT backups  we will also
 	 * modify each of the reserved GDT dindirect blocks.
 	 */
-	credit = flex_gd->count * 4 + reserved_gdb;
+	credit = 3;	/* sb, resize inode, resize inode dindirect */
+	/* GDT blocks */
+	credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb));
+	credit += reserved_gdb;	/* Reserved GDT dindirect blocks */
 	handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit);
 	if (IS_ERR(handle)) {
 		err = PTR_ERR(handle);

fs/ext4/symlink.c

@@ -74,7 +74,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
 		goto errout;
 	}
 	pstr.name = paddr;
-	res = _ext4_fname_disk_to_usr(ctx, &cstr, &pstr);
+	res = _ext4_fname_disk_to_usr(ctx, NULL, &cstr, &pstr);
 	if (res < 0)
 		goto errout;
 	/* Null-terminate the name */