From d229959072eba40e1c2a4f53f8af17f1e770eb66 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 18 May 2015 13:15:47 -0400 Subject: ext4 crypto: don't allocate a page when encrypting/decrypting file names Signed-off-by: Theodore Ts'o --- fs/ext4/ext4_crypto.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index d75159c101ce..552424ae3ab3 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -123,10 +123,8 @@ struct ext4_str { struct ext4_fname_crypto_ctx { u32 lim; - char tmp_buf[EXT4_CRYPTO_BLOCK_SIZE]; struct crypto_ablkcipher *ctfm; struct crypto_hash *htfm; - struct page *workpage; struct ext4_encryption_key key; unsigned flags : 8; unsigned has_valid_key : 1; -- cgit v1.2.3-59-g8ed1b From e2881b1b51d871a72911faf2fc7e090655940506 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 18 May 2015 13:16:47 -0400 Subject: ext4 crypto: separate kernel and userspace structure for the key Use struct ext4_encryption_key only for the master key passed via the kernel keyring. For internal kernel space users, we now use struct ext4_crypt_info. This will allow us to put information from the policy structure so we can cache it and avoid needing to constantly looking up the extended attribute. We will do this in a spearate patch. This patch is mostly mechnical to make it easier for patch review. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 18 +++++++++--------- fs/ext4/crypto_fname.c | 33 ++++++++++----------------------- fs/ext4/crypto_key.c | 21 +++++++++++---------- fs/ext4/ext4.h | 2 +- fs/ext4/ext4_crypto.h | 15 +++++++++++---- fs/ext4/super.c | 2 +- 6 files changed, 43 insertions(+), 48 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 8ff15273ab0c..918200ed9bf8 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -118,7 +118,7 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) struct ext4_crypto_ctx *ctx = NULL; int res = 0; unsigned long flags; - struct ext4_encryption_key *key = &EXT4_I(inode)->i_encryption_key; + struct ext4_crypt_info *ci = &EXT4_I(inode)->i_crypt_info; if (!ext4_read_workqueue) ext4_init_crypto(); @@ -152,14 +152,14 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) /* Allocate a new Crypto API context if we don't already have * one or if it isn't the right mode. */ - BUG_ON(key->mode == EXT4_ENCRYPTION_MODE_INVALID); - if (ctx->tfm && (ctx->mode != key->mode)) { + BUG_ON(ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID); + if (ctx->tfm && (ctx->mode != ci->ci_mode)) { crypto_free_tfm(ctx->tfm); ctx->tfm = NULL; ctx->mode = EXT4_ENCRYPTION_MODE_INVALID; } if (!ctx->tfm) { - switch (key->mode) { + switch (ci->ci_mode) { case EXT4_ENCRYPTION_MODE_AES_256_XTS: ctx->tfm = crypto_ablkcipher_tfm( crypto_alloc_ablkcipher("xts(aes)", 0, 0)); @@ -177,9 +177,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) ctx->tfm = NULL; goto out; } - ctx->mode = key->mode; + ctx->mode = ci->ci_mode; } - BUG_ON(key->size != ext4_encryption_key_size(key->mode)); + BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_mode)); /* There shouldn't be a bounce page attached to the crypto * context at this point. */ @@ -322,7 +322,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, int res = 0; BUG_ON(!ctx->tfm); - BUG_ON(ctx->mode != ei->i_encryption_key.mode); + BUG_ON(ctx->mode != ei->i_crypt_info.ci_mode); if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) { printk_ratelimited(KERN_ERR @@ -334,8 +334,8 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, crypto_ablkcipher_clear_flags(atfm, ~0); crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY); - res = crypto_ablkcipher_setkey(atfm, ei->i_encryption_key.raw, - ei->i_encryption_key.size); + res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info.ci_raw, + ei->i_crypt_info.ci_size); if (res) { printk_ratelimited(KERN_ERR "%s: crypto_ablkcipher_setkey() failed\n", diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c index 23d7f1d56b00..d9f08ddbfda2 100644 --- a/fs/ext4/crypto_fname.c +++ b/fs/ext4/crypto_fname.c @@ -277,34 +277,25 @@ void ext4_put_fname_crypto_ctx(struct ext4_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) + const struct ext4_crypt_info *ci) { 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) { + if (ci->ci_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)); + memset(&ctx->ci, 0, sizeof(ctx->ci)); } else { - memcpy(&ctx->key, key, sizeof(struct ext4_encryption_key)); + memcpy(&ctx->ci, ci, sizeof(struct ext4_crypt_info)); } - ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == key->mode) + ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == ci->ci_mode) ? 0 : 1; ctx->ctfm_key_is_ready = 0; ctx->ctfm = NULL; @@ -335,21 +326,17 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx( 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)); + /* Get a crypto context based on the key. */ + ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_crypt_info)); 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) { + if (ctx->ci.ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { printk_once(KERN_WARNING "ext4: unsupported key mode %d\n", - ctx->key.mode); + ctx->ci.ci_mode); return ERR_PTR(-ENOKEY); } @@ -389,7 +376,7 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx( * are pretty weak, * we directly use the inode master key */ res = crypto_ablkcipher_setkey(ctx->ctfm, - ctx->key.raw, ctx->key.size); + ctx->ci.ci_raw, ctx->ci.ci_size); if (res) { ext4_put_fname_crypto_ctx(&ctx); return ERR_PTR(-EIO); diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index 52170d0b7c40..ec6635dc50f9 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -91,7 +91,7 @@ out: int ext4_generate_encryption_key(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_encryption_key *crypt_key = &ei->i_encryption_key; + struct ext4_crypt_info *crypt_info = &ei->i_crypt_info; char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE + (EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1]; struct key *keyring_key = NULL; @@ -112,17 +112,17 @@ int ext4_generate_encryption_key(struct inode *inode) ei->i_crypt_policy_flags = ctx.flags; if (S_ISREG(inode->i_mode)) - crypt_key->mode = ctx.contents_encryption_mode; + crypt_info->ci_mode = ctx.contents_encryption_mode; else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) - crypt_key->mode = ctx.filenames_encryption_mode; + crypt_info->ci_mode = ctx.filenames_encryption_mode; else { printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n"); BUG(); } - crypt_key->size = ext4_encryption_key_size(crypt_key->mode); - BUG_ON(!crypt_key->size); + crypt_info->ci_size = ext4_encryption_key_size(crypt_info->ci_mode); + BUG_ON(!crypt_info->ci_size); if (DUMMY_ENCRYPTION_ENABLED(sbi)) { - memset(crypt_key->raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE); + memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE); goto out; } memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX, @@ -148,19 +148,20 @@ int ext4_generate_encryption_key(struct inode *inode) BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE != EXT4_KEY_DERIVATION_NONCE_SIZE); BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE); - res = ext4_derive_key_aes(ctx.nonce, master_key->raw, crypt_key->raw); + res = ext4_derive_key_aes(ctx.nonce, master_key->raw, + crypt_info->ci_raw); out: if (keyring_key) key_put(keyring_key); if (res < 0) - crypt_key->mode = EXT4_ENCRYPTION_MODE_INVALID; + crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID; return res; } int ext4_has_encryption_key(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_encryption_key *crypt_key = &ei->i_encryption_key; + struct ext4_crypt_info *crypt_info = &ei->i_crypt_info; - return (crypt_key->mode != EXT4_ENCRYPTION_MODE_INVALID); + return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID); } diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 866831e7c136..3cf3bcb6b239 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -955,7 +955,7 @@ struct ext4_inode_info { #ifdef CONFIG_EXT4_FS_ENCRYPTION /* Encryption params */ - struct ext4_encryption_key i_encryption_key; + struct ext4_crypt_info i_crypt_info; #endif }; diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index 552424ae3ab3..deecbe8968d1 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -66,10 +66,17 @@ struct ext4_encryption_context { #define EXT4_KEY_DESC_PREFIX "ext4:" #define EXT4_KEY_DESC_PREFIX_SIZE 5 +/* This is passed in from userspace into the kernel keyring */ struct ext4_encryption_key { - uint32_t mode; - char raw[EXT4_MAX_KEY_SIZE]; - uint32_t size; + __u32 mode; + char raw[EXT4_MAX_KEY_SIZE]; + __u32 size; +} __attribute__((__packed__)); + +struct ext4_crypt_info { + unsigned char ci_mode; + unsigned char ci_size; + char ci_raw[EXT4_MAX_KEY_SIZE]; }; #define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 @@ -125,7 +132,7 @@ struct ext4_fname_crypto_ctx { u32 lim; struct crypto_ablkcipher *ctfm; struct crypto_hash *htfm; - struct ext4_encryption_key key; + struct ext4_crypt_info ci; unsigned flags : 8; unsigned has_valid_key : 1; unsigned ctfm_key_is_ready : 1; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index ca9d4a2fed41..bcd7a4bc9036 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -879,7 +879,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) atomic_set(&ei->i_unwritten, 0); INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); #ifdef CONFIG_EXT4_FS_ENCRYPTION - ei->i_encryption_key.mode = EXT4_ENCRYPTION_MODE_INVALID; + ei->i_crypt_info.ci_mode = EXT4_ENCRYPTION_MODE_INVALID; #endif return &ei->vfs_inode; -- cgit v1.2.3-59-g8ed1b From b7236e21d55ff9008737621c84dd8ee6c37c7c6d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 18 May 2015 13:17:47 -0400 Subject: ext4 crypto: reorganize how we store keys in the inode This is a pretty massive patch which does a number of different things: 1) The per-inode encryption information is now stored in an allocated data structure, ext4_crypt_info, instead of directly in the node. This reduces the size usage of an in-memory inode when it is not using encryption. 2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode encryption structure instead. This remove an unnecessary memory allocation and free for the fname_crypto_ctx as well as allowing us to reuse the ctfm in a directory for multiple lookups and file creations. 3) We also cache the inode's policy information in the ext4_crypt_info structure so we don't have to continually read it out of the extended attributes. 4) We now keep the keyring key in the inode's encryption structure instead of releasing it after we are done using it to derive the per-inode key. This allows us to test to see if the key has been revoked; if it has, we prevent the use of the derived key and free it. 5) When an inode is released (or when the derived key is freed), we will use memset_explicit() to zero out the derived key, so it's not left hanging around in memory. This implies that when a user logs out, it is important to first revoke the key, and then unlink it, and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to release any decrypted pages and dcache entries from the system caches. 6) All this, and we also shrink the number of lines of code by around 100. :-) Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 9 +- fs/ext4/crypto_fname.c | 284 +++++++++++++----------------------------------- fs/ext4/crypto_key.c | 74 ++++++++++--- fs/ext4/crypto_policy.c | 76 +++++++------ fs/ext4/dir.c | 21 ++-- fs/ext4/ext4.h | 44 +++++--- fs/ext4/ext4_crypto.h | 16 +-- fs/ext4/file.c | 4 +- fs/ext4/namei.c | 42 +++---- fs/ext4/super.c | 7 +- fs/ext4/symlink.c | 15 +-- 11 files changed, 246 insertions(+), 346 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 918200ed9bf8..3a25aa4f3d94 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -118,8 +118,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) struct ext4_crypto_ctx *ctx = NULL; int res = 0; unsigned long flags; - struct ext4_crypt_info *ci = &EXT4_I(inode)->i_crypt_info; + struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; + BUG_ON(ci == NULL); if (!ext4_read_workqueue) ext4_init_crypto(); @@ -322,7 +323,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, int res = 0; BUG_ON(!ctx->tfm); - BUG_ON(ctx->mode != ei->i_crypt_info.ci_mode); + BUG_ON(ctx->mode != ei->i_crypt_info->ci_mode); if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) { printk_ratelimited(KERN_ERR @@ -334,8 +335,8 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, crypto_ablkcipher_clear_flags(atfm, ~0); crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY); - res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info.ci_raw, - ei->i_crypt_info.ci_size); + res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info->ci_raw, + ei->i_crypt_info->ci_size); if (res) { printk_ratelimited(KERN_ERR "%s: crypto_ablkcipher_setkey() failed\n", diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c index d9f08ddbfda2..374d0e790315 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() - * @@ -55,28 +61,30 @@ 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 src_sg, dst_sg; - int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK); + 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 = ext4_fname_crypto_round_up(ciphertext_len, padding); - ciphertext_len = (ciphertext_len > ctx->lim) - ? ctx->lim : ciphertext_len; + ciphertext_len = (ciphertext_len > lim) + ? lim : ciphertext_len; if (ciphertext_len <= sizeof(buf)) { workbuf = buf; @@ -134,7 +142,7 @@ 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) { @@ -142,11 +150,13 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx, struct ablkcipher_request *req = NULL; DECLARE_EXT4_COMPLETION_RESULT(ecr); struct scatterlist src_sg, dst_sg; - 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]; + 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; @@ -242,171 +252,50 @@ static int digest_decode(const char *src, int len, char *dst) return cp - dst; } -/** - * 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); - kfree(ctx); -} - -/** - * 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) +int ext4_setup_fname_crypto(struct inode *inode) { - if (*ctx == NULL || IS_ERR(*ctx)) - return; - ext4_free_fname_crypto_ctx(*ctx); - *ctx = NULL; -} - -/** - * ext4_alloc_fname_crypto_ctx() - - */ -struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx( - const struct ext4_crypt_info *ci) -{ - struct ext4_fname_crypto_ctx *ctx; - - ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS); - if (ctx == NULL) - return ERR_PTR(-ENOMEM); - if (ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID) { - /* This will automatically set key mode to invalid - * As enum for ENCRYPTION_MODE_INVALID is zero */ - memset(&ctx->ci, 0, sizeof(ctx->ci)); - } else { - memcpy(&ctx->ci, ci, sizeof(struct ext4_crypt_info)); - } - ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == ci->ci_mode) - ? 0 : 1; - ctx->ctfm_key_is_ready = 0; - ctx->ctfm = NULL; - ctx->htfm = 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); + struct ext4_crypt_info *ci = ei->i_crypt_info; + struct crypto_ablkcipher *ctfm; 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. */ - ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_crypt_info)); - if (IS_ERR(ctx)) - return ctx; - - ctx->flags = ei->i_crypt_policy_flags; - if (ctx->has_valid_key) { - if (ctx->ci.ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { - printk_once(KERN_WARNING - "ext4: unsupported key mode %d\n", - ctx->ci.ci_mode); - return ERR_PTR(-ENOKEY); - } + return 0; - /* 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); - } - 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->ci.ci_raw, ctx->ci.ci_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); + res = ext4_get_encryption_info(inode); + if (res < 0) + return res; + ci = ei->i_crypt_info; + + if (!ci || ci->ci_ctfm) + return 0; + + if (ci->ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { + printk_once(KERN_WARNING "ext4: unsupported key mode %d\n", + ci->ci_mode); + return -ENOKEY; } - 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); + + ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0); + if (!ctfm || IS_ERR(ctfm)) { + res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; + printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n", + __func__, res); + return res; } + crypto_ablkcipher_clear_flags(ctfm, ~0); + crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm), + CRYPTO_TFM_REQ_WEAK_KEY); - return ctx; + res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size); + if (res) { + crypto_free_ablkcipher(ctfm); + return -EIO; + } + ci->ci_ctfm = ctfm; + return 0; } /** @@ -419,41 +308,21 @@ 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) -{ - u32 ciphertext_len; - int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK); - - 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 = ext4_fname_crypto_round_up(ciphertext_len, padding); - ciphertext_len = (ciphertext_len > ctx->lim) - ? ctx->lim : ciphertext_len; - return (int) ciphertext_len; -} - /** * ext4_fname_crypto_alloc_obuff() - * * 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; - int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK); + int padding = 16; + struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; - if (!ctx) - return -EIO; + if (ci) + padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK); if (padding < EXT4_CRYPTO_BLOCK_SIZE) padding = EXT4_CRYPTO_BLOCK_SIZE; olen = ext4_fname_crypto_round_up(ilen, padding); @@ -484,7 +353,7 @@ 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, +int _ext4_fname_disk_to_usr(struct inode *inode, struct dx_hash_info *hinfo, const struct ext4_str *iname, struct ext4_str *oname) @@ -492,8 +361,6 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx, char buf[24]; int ret; - if (ctx == NULL) - return -EIO; if (iname->len < 3) { /*Check for . and .. */ if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') { @@ -503,8 +370,8 @@ 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); + 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); @@ -523,7 +390,7 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx, 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) @@ -531,21 +398,20 @@ int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx, struct ext4_str iname = {.name = (unsigned char *) de->name, .len = de->name_len }; - return _ext4_fname_disk_to_usr(ctx, hinfo, &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] == '.' && @@ -556,8 +422,8 @@ 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 @@ -569,16 +435,13 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx, int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, int lookup, struct ext4_filename *fname) { - struct ext4_fname_crypto_ctx *ctx; + struct ext4_crypt_info *ci; int ret = 0, bigname = 0; memset(fname, 0, sizeof(struct ext4_filename)); fname->usr_fname = iname; - ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); - if (IS_ERR(ctx)) - return PTR_ERR(ctx); - if ((ctx == NULL) || + if (!ext4_encrypted_inode(dir) || ((iname->name[0] == '.') && ((iname->len == 1) || ((iname->name[1] == '.') && (iname->len == 2))))) { @@ -586,12 +449,16 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, fname->disk_name.len = iname->len; goto out; } - if (ctx->has_valid_key) { - ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len, + ret = ext4_setup_fname_crypto(dir); + if (ret) + return ret; + ci = EXT4_I(dir)->i_crypt_info; + if (ci) { + ret = ext4_fname_crypto_alloc_buffer(dir, iname->len, &fname->crypto_buf); if (ret < 0) goto out; - ret = ext4_fname_encrypt(ctx, iname, &fname->crypto_buf); + ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf); if (ret < 0) goto out; fname->disk_name.name = fname->crypto_buf.name; @@ -634,7 +501,6 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, } ret = 0; out: - ext4_put_fname_crypto_ctx(&ctx); return ret; } diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index ec6635dc50f9..0075e43ffea6 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -84,14 +84,26 @@ out: return res; } -/** - * ext4_generate_encryption_key() - generates an encryption key - * @inode: The inode to generate the encryption key for. - */ -int ext4_generate_encryption_key(struct inode *inode) +void ext4_free_encryption_info(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_crypt_info *ci = ei->i_crypt_info; + + if (!ci) + return; + + if (ci->ci_keyring_key) + key_put(ci->ci_keyring_key); + crypto_free_ablkcipher(ci->ci_ctfm); + memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw)); + kfree(ci); + ei->i_crypt_info = NULL; +} + +int _ext4_get_encryption_info(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_crypt_info *crypt_info = &ei->i_crypt_info; + struct ext4_crypt_info *crypt_info; char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE + (EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1]; struct key *keyring_key = NULL; @@ -99,18 +111,40 @@ int ext4_generate_encryption_key(struct inode *inode) struct ext4_encryption_context ctx; struct user_key_payload *ukp; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); - int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION, - EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, - &ctx, sizeof(ctx)); + int res; - if (res != sizeof(ctx)) { - if (res > 0) - res = -EINVAL; - goto out; + if (ei->i_crypt_info) { + if (!ei->i_crypt_info->ci_keyring_key || + key_validate(ei->i_crypt_info->ci_keyring_key) == 0) + return 0; + ext4_free_encryption_info(inode); } + + res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION, + EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, + &ctx, sizeof(ctx)); + if (res < 0) { + if (!DUMMY_ENCRYPTION_ENABLED(sbi)) + return res; + ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS; + ctx.filenames_encryption_mode = + EXT4_ENCRYPTION_MODE_AES_256_CTS; + ctx.flags = 0; + } else if (res != sizeof(ctx)) + return -EINVAL; res = 0; + crypt_info = kmalloc(sizeof(struct ext4_crypt_info), GFP_KERNEL); + if (!crypt_info) + return -ENOMEM; + ei->i_crypt_policy_flags = ctx.flags; + crypt_info->ci_flags = ctx.flags; + crypt_info->ci_data_mode = ctx.contents_encryption_mode; + crypt_info->ci_filename_mode = ctx.filenames_encryption_mode; + crypt_info->ci_ctfm = NULL; + memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, + sizeof(crypt_info->ci_master_key)); if (S_ISREG(inode->i_mode)) crypt_info->ci_mode = ctx.contents_encryption_mode; else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) @@ -151,17 +185,23 @@ int ext4_generate_encryption_key(struct inode *inode) res = ext4_derive_key_aes(ctx.nonce, master_key->raw, crypt_info->ci_raw); out: + if (res < 0) { + if (res == -ENOKEY) + res = 0; + kfree(crypt_info); + } else { + ei->i_crypt_info = crypt_info; + crypt_info->ci_keyring_key = keyring_key; + keyring_key = NULL; + } if (keyring_key) key_put(keyring_key); - if (res < 0) - crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID; return res; } int ext4_has_encryption_key(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_crypt_info *crypt_info = &ei->i_crypt_info; - return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID); + return (ei->i_crypt_info != NULL); } diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c index a6d6291aea16..370d3aa0a9cf 100644 --- a/fs/ext4/crypto_policy.c +++ b/fs/ext4/crypto_policy.c @@ -126,7 +126,7 @@ int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy) int ext4_is_child_context_consistent_with_parent(struct inode *parent, struct inode *child) { - struct ext4_encryption_context parent_ctx, child_ctx; + struct ext4_crypt_info *parent_ci, *child_ci; int res; if ((parent == NULL) || (child == NULL)) { @@ -136,26 +136,28 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent, /* no restrictions if the parent directory is not encrypted */ if (!ext4_encrypted_inode(parent)) return 1; - res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION, - EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, - &parent_ctx, sizeof(parent_ctx)); - if (res != sizeof(parent_ctx)) - return 0; /* if the child directory is not encrypted, this is always a problem */ if (!ext4_encrypted_inode(child)) return 0; - res = ext4_xattr_get(child, EXT4_XATTR_INDEX_ENCRYPTION, - EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, - &child_ctx, sizeof(child_ctx)); - if (res != sizeof(child_ctx)) + res = ext4_get_encryption_info(parent); + if (res) + return 0; + res = ext4_get_encryption_info(child); + if (res) + return 0; + parent_ci = EXT4_I(parent)->i_crypt_info; + child_ci = EXT4_I(child)->i_crypt_info; + if (!parent_ci && !child_ci) + return 1; + if (!parent_ci || !child_ci) return 0; - return (memcmp(parent_ctx.master_key_descriptor, - child_ctx.master_key_descriptor, + + return (memcmp(parent_ci->ci_master_key, + child_ci->ci_master_key, EXT4_KEY_DESCRIPTOR_SIZE) == 0 && - (parent_ctx.contents_encryption_mode == - child_ctx.contents_encryption_mode) && - (parent_ctx.filenames_encryption_mode == - child_ctx.filenames_encryption_mode)); + (parent_ci->ci_data_mode == child_ci->ci_data_mode) && + (parent_ci->ci_filename_mode == child_ci->ci_filename_mode) && + (parent_ci->ci_flags == child_ci->ci_flags)); } /** @@ -168,31 +170,37 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent, int ext4_inherit_context(struct inode *parent, struct inode *child) { struct ext4_encryption_context ctx; - int res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION, - EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, - &ctx, sizeof(ctx)); + struct ext4_crypt_info *ci; + int res; + + res = ext4_get_encryption_info(parent); + if (res < 0) + return res; + ci = EXT4_I(parent)->i_crypt_info; + BUG_ON(ci == NULL); - if (res != sizeof(ctx)) { - if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) { - ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1; - ctx.contents_encryption_mode = - 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; - } else { - goto out; - } + ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1; + if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) { + ctx.contents_encryption_mode = 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; + } else { + ctx.contents_encryption_mode = ci->ci_data_mode; + ctx.filenames_encryption_mode = ci->ci_filename_mode; + ctx.flags = ci->ci_flags; + memcpy(ctx.master_key_descriptor, ci->ci_master_key, + EXT4_KEY_DESCRIPTOR_SIZE); } get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE); res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION, EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx, sizeof(ctx), 0); -out: if (!res) ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT); return res; + } diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index d799d5d571e9..28cb94fbb1c9 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -110,7 +110,6 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) struct super_block *sb = inode->i_sb; struct buffer_head *bh = NULL; int dir_has_error = 0; - struct ext4_fname_crypto_ctx *enc_ctx = NULL; struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; if (is_dx_dir(inode)) { @@ -134,16 +133,14 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) return err; } - enc_ctx = ext4_get_fname_crypto_ctx(inode, EXT4_NAME_LEN); - if (IS_ERR(enc_ctx)) - return PTR_ERR(enc_ctx); - if (enc_ctx) { - err = ext4_fname_crypto_alloc_buffer(enc_ctx, EXT4_NAME_LEN, + err = ext4_setup_fname_crypto(inode); + if (err) + return err; + if (ext4_encrypted_inode(inode)) { + err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN, &fname_crypto_str); - if (err < 0) { - ext4_put_fname_crypto_ctx(&enc_ctx); + if (err < 0) return err; - } } offset = ctx->pos & (sb->s_blocksize - 1); @@ -239,8 +236,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); if (le32_to_cpu(de->inode)) { - if (enc_ctx == NULL) { - /* Directory is not encrypted */ + if (!ext4_encrypted_inode(inode)) { if (!dir_emit(ctx, de->name, de->name_len, le32_to_cpu(de->inode), @@ -250,7 +246,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) int save_len = fname_crypto_str.len; /* Directory is encrypted */ - err = ext4_fname_disk_to_usr(enc_ctx, + err = ext4_fname_disk_to_usr(inode, NULL, de, &fname_crypto_str); fname_crypto_str.len = save_len; if (err < 0) @@ -275,7 +271,6 @@ done: err = 0; errout: #ifdef CONFIG_EXT4_FS_ENCRYPTION - ext4_put_fname_crypto_ctx(&enc_ctx); ext4_fname_crypto_free_buffer(&fname_crypto_str); #endif brelse(bh); diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3cf3bcb6b239..cac1968e63cb 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -955,7 +955,7 @@ struct ext4_inode_info { #ifdef CONFIG_EXT4_FS_ENCRYPTION /* Encryption params */ - struct ext4_crypt_info i_crypt_info; + struct ext4_crypt_info *i_crypt_info; #endif }; @@ -2096,37 +2096,30 @@ static inline int ext4_sb_has_crypto(struct super_block *sb) /* crypto_fname.c */ bool ext4_valid_filenames_enc_mode(uint32_t mode); u32 ext4_fname_crypto_round_up(u32 size, u32 blksize); -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); -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_str *iname, struct ext4_str *oname); -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); -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 ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx, - u32 namelen); #ifdef CONFIG_EXT4_FS_ENCRYPTION -void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx); -struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode, - u32 max_len); +int ext4_setup_fname_crypto(struct inode *inode); void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str); int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, int lookup, struct ext4_filename *fname); void ext4_fname_free_filename(struct ext4_filename *fname); #else static inline -void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx) { } -static inline -struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode, - u32 max_len) +int ext4_setup_fname_crypto(struct inode *inode) { - return NULL; + return 0; } static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { } static inline int ext4_fname_setup_filename(struct inode *dir, @@ -2143,15 +2136,34 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { } /* crypto_key.c */ -int ext4_generate_encryption_key(struct inode *inode); +void ext4_free_encryption_info(struct inode *inode); +int _ext4_get_encryption_info(struct inode *inode); #ifdef CONFIG_EXT4_FS_ENCRYPTION int ext4_has_encryption_key(struct inode *inode); + +static inline int ext4_get_encryption_info(struct inode *inode) +{ + struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; + + if (!ci || + (ci->ci_keyring_key && + (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD))))) + return _ext4_get_encryption_info(inode); + return 0; +} + #else static inline int ext4_has_encryption_key(struct inode *inode) { return 0; } +static inline int ext4_get_encryption_info(struct inode *inode) +{ + return 0; +} #endif diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index deecbe8968d1..d29687c232bd 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -76,7 +76,13 @@ struct ext4_encryption_key { struct ext4_crypt_info { unsigned char ci_mode; unsigned char ci_size; + char ci_data_mode; + char ci_filename_mode; + char ci_flags; + struct crypto_ablkcipher *ci_ctfm; + struct key *ci_keyring_key; char ci_raw[EXT4_MAX_KEY_SIZE]; + char ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE]; }; #define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 @@ -128,16 +134,6 @@ struct ext4_str { u32 len; }; -struct ext4_fname_crypto_ctx { - u32 lim; - struct crypto_ablkcipher *ctfm; - struct crypto_hash *htfm; - struct ext4_crypt_info ci; - unsigned flags : 8; - unsigned has_valid_key : 1; - unsigned ctfm_key_is_ready : 1; -}; - /** * For encrypted symlinks, the ciphertext length is stored at the beginning * of the string in little-endian format. diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 0613c256c344..875ca6b95a4b 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -223,7 +223,7 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) struct inode *inode = file->f_mapping->host; if (ext4_encrypted_inode(inode)) { - int err = ext4_generate_encryption_key(inode); + int err = ext4_get_encryption_info(inode); if (err) return 0; } @@ -289,7 +289,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) } ret = dquot_file_open(inode, filp); if (!ret && ext4_encrypted_inode(inode)) { - ret = ext4_generate_encryption_key(inode); + ret = ext4_get_encryption_info(inode); if (ret) ret = -EACCES; } diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index b3406434c267..9bed99fdd81a 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -607,17 +607,14 @@ static struct stats dx_show_leaf(struct inode *dir, char *name; struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; - struct ext4_fname_crypto_ctx *ctx = NULL; int res; name = de->name; len = de->name_len; - ctx = ext4_get_fname_crypto_ctx(dir, - EXT4_NAME_LEN); - if (IS_ERR(ctx)) { - printk(KERN_WARNING "Error acquiring" - " crypto ctxt--skipping crypto\n"); - ctx = NULL; + res = ext4_setup_fname_crypto(dir); + if (res) { + printk(KERN_WARNING "Error setting up" + " fname crypto: %d\n", res); } if (ctx == NULL) { /* Directory is not encrypted */ @@ -637,7 +634,6 @@ static struct stats dx_show_leaf(struct inode *dir, "allocating crypto " "buffer--skipping " "crypto\n"); - ext4_put_fname_crypto_ctx(&ctx); ctx = NULL; } res = ext4_fname_disk_to_usr(ctx, NULL, de, @@ -658,7 +654,6 @@ static struct stats dx_show_leaf(struct inode *dir, printk("%*.s:(E)%x.%u ", len, name, h.hash, (unsigned) ((char *) de - base)); - ext4_put_fname_crypto_ctx(&ctx); ext4_fname_crypto_free_buffer( &fname_crypto_str); } @@ -944,7 +939,6 @@ static int htree_dirblock_to_tree(struct file *dir_file, struct buffer_head *bh; struct ext4_dir_entry_2 *de, *top; int err = 0, count = 0; - struct ext4_fname_crypto_ctx *ctx = NULL; struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str; dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", @@ -959,17 +953,15 @@ static int htree_dirblock_to_tree(struct file *dir_file, EXT4_DIR_REC_LEN(0)); #ifdef CONFIG_EXT4_FS_ENCRYPTION /* Check if the directory is encrypted */ - ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); - if (IS_ERR(ctx)) { - err = PTR_ERR(ctx); + err = ext4_setup_fname_crypto(dir); + if (err) { brelse(bh); return err; } - if (ctx != NULL) { - err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN, + if (ext4_encrypted_inode(dir)) { + err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN, &fname_crypto_str); if (err < 0) { - ext4_put_fname_crypto_ctx(&ctx); brelse(bh); return err; } @@ -990,8 +982,7 @@ static int htree_dirblock_to_tree(struct file *dir_file, continue; if (de->inode == 0) continue; - if (ctx == NULL) { - /* Directory is not encrypted */ + if (!ext4_encrypted_inode(dir)) { tmp_str.name = de->name; tmp_str.len = de->name_len; err = ext4_htree_store_dirent(dir_file, @@ -1001,7 +992,7 @@ static int htree_dirblock_to_tree(struct file *dir_file, int save_len = fname_crypto_str.len; /* Directory is encrypted */ - err = ext4_fname_disk_to_usr(ctx, hinfo, de, + err = ext4_fname_disk_to_usr(dir, hinfo, de, &fname_crypto_str); if (err < 0) { count = err; @@ -1021,7 +1012,6 @@ static int htree_dirblock_to_tree(struct file *dir_file, errout: brelse(bh); #ifdef CONFIG_EXT4_FS_ENCRYPTION - ext4_put_fname_crypto_ctx(&ctx); ext4_fname_crypto_free_buffer(&fname_crypto_str); #endif return count; @@ -3107,7 +3097,6 @@ static int ext4_symlink(struct inode *dir, } if (encryption_required) { - struct ext4_fname_crypto_ctx *ctx = NULL; struct qstr istr; struct ext4_str ostr; @@ -3119,19 +3108,14 @@ static int ext4_symlink(struct inode *dir, err = ext4_inherit_context(dir, inode); if (err) goto err_drop_inode; - ctx = ext4_get_fname_crypto_ctx(inode, - inode->i_sb->s_blocksize); - if (IS_ERR_OR_NULL(ctx)) { - /* We just set the policy, so ctx should not be NULL */ - err = (ctx == NULL) ? -EIO : PTR_ERR(ctx); + err = ext4_setup_fname_crypto(inode); + if (err) goto err_drop_inode; - } istr.name = (const unsigned char *) symname; istr.len = len; ostr.name = sd->encrypted_path; ostr.len = disk_link.len; - err = ext4_fname_usr_to_disk(ctx, &istr, &ostr); - ext4_put_fname_crypto_ctx(&ctx); + err = ext4_fname_usr_to_disk(inode, &istr, &ostr); if (err < 0) goto err_drop_inode; sd->len = cpu_to_le16(ostr.len); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index bcd7a4bc9036..e0dac100fbe6 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -879,9 +879,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) atomic_set(&ei->i_unwritten, 0); INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); #ifdef CONFIG_EXT4_FS_ENCRYPTION - ei->i_crypt_info.ci_mode = EXT4_ENCRYPTION_MODE_INVALID; + ei->i_crypt_info = NULL; #endif - return &ei->vfs_inode; } @@ -958,6 +957,10 @@ void ext4_clear_inode(struct inode *inode) jbd2_free_inode(EXT4_I(inode)->jinode); EXT4_I(inode)->jinode = NULL; } +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if (EXT4_I(inode)->i_crypt_info) + ext4_free_encryption_info(inode); +#endif } static struct inode *ext4_nfs_get_inode(struct super_block *sb, diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index ca65d45c7f8d..32870881188e 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -29,7 +29,6 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) char *caddr, *paddr = NULL; struct ext4_str cstr, pstr; struct inode *inode = d_inode(dentry); - struct ext4_fname_crypto_ctx *ctx = NULL; struct ext4_encrypted_symlink_data *sd; loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1); int res; @@ -38,19 +37,17 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) if (!ext4_encrypted_inode(inode)) return page_follow_link_light(dentry, nd); - ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize); - if (IS_ERR(ctx)) - return ctx; + res = ext4_setup_fname_crypto(inode); + if (res) + return ERR_PTR(res); if (ext4_inode_is_fast_symlink(inode)) { caddr = (char *) EXT4_I(inode)->i_data; max_size = sizeof(EXT4_I(inode)->i_data); } else { cpage = read_mapping_page(inode->i_mapping, 0, NULL); - if (IS_ERR(cpage)) { - ext4_put_fname_crypto_ctx(&ctx); + if (IS_ERR(cpage)) return cpage; - } caddr = kmap(cpage); caddr[size] = 0; } @@ -75,21 +72,19 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) } pstr.name = paddr; pstr.len = plen; - res = _ext4_fname_disk_to_usr(ctx, NULL, &cstr, &pstr); + res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr); if (res < 0) goto errout; /* Null-terminate the name */ if (res <= plen) paddr[res] = '\0'; nd_set_link(nd, paddr); - ext4_put_fname_crypto_ctx(&ctx); if (cpage) { kunmap(cpage); page_cache_release(cpage); } return NULL; errout: - ext4_put_fname_crypto_ctx(&ctx); if (cpage) { kunmap(cpage); page_cache_release(cpage); -- cgit v1.2.3-59-g8ed1b From 1aaa6e8b24114757a836ae0e62d2096deb76f274 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 18 May 2015 13:20:47 -0400 Subject: ext4 crypto: get rid of ci_mode from struct ext4_crypt_info The ci_mode field was superfluous, and getting rid of it gets rid of an unused hole in the structure. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 11 +++++------ fs/ext4/crypto_fname.c | 4 ++-- fs/ext4/crypto_key.c | 11 +++++------ fs/ext4/ext4_crypto.h | 1 - 4 files changed, 12 insertions(+), 15 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 1c34f0eb125b..9969d054cd88 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -137,14 +137,13 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) /* Allocate a new Crypto API context if we don't already have * one or if it isn't the right mode. */ - BUG_ON(ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID); - if (ctx->tfm && (ctx->mode != ci->ci_mode)) { + if (ctx->tfm && (ctx->mode != ci->ci_data_mode)) { crypto_free_tfm(ctx->tfm); ctx->tfm = NULL; ctx->mode = EXT4_ENCRYPTION_MODE_INVALID; } if (!ctx->tfm) { - switch (ci->ci_mode) { + switch (ci->ci_data_mode) { case EXT4_ENCRYPTION_MODE_AES_256_XTS: ctx->tfm = crypto_ablkcipher_tfm( crypto_alloc_ablkcipher("xts(aes)", 0, 0)); @@ -162,9 +161,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) ctx->tfm = NULL; goto out; } - ctx->mode = ci->ci_mode; + ctx->mode = ci->ci_data_mode; } - BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_mode)); + BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_data_mode)); /* There shouldn't be a bounce page attached to the crypto * context at this point. */ @@ -321,7 +320,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, int res = 0; BUG_ON(!ctx->tfm); - BUG_ON(ctx->mode != ei->i_crypt_info->ci_mode); + BUG_ON(ctx->mode != ei->i_crypt_info->ci_data_mode); if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) { printk_ratelimited(KERN_ERR diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c index 374d0e790315..e63dd294d7aa 100644 --- a/fs/ext4/crypto_fname.c +++ b/fs/ext4/crypto_fname.c @@ -272,9 +272,9 @@ int ext4_setup_fname_crypto(struct inode *inode) if (!ci || ci->ci_ctfm) return 0; - if (ci->ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { + if (ci->ci_filename_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { printk_once(KERN_WARNING "ext4: unsupported key mode %d\n", - ci->ci_mode); + ci->ci_filename_mode); return -ENOKEY; } diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index d6abe4687cd5..858d7d67a4e1 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -152,14 +152,13 @@ int _ext4_get_encryption_info(struct inode *inode) memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, sizeof(crypt_info->ci_master_key)); if (S_ISREG(inode->i_mode)) - crypt_info->ci_mode = ctx.contents_encryption_mode; + crypt_info->ci_size = + ext4_encryption_key_size(crypt_info->ci_data_mode); else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) - crypt_info->ci_mode = ctx.filenames_encryption_mode; - else { - printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n"); + crypt_info->ci_size = + ext4_encryption_key_size(crypt_info->ci_filename_mode); + else BUG(); - } - crypt_info->ci_size = ext4_encryption_key_size(crypt_info->ci_mode); BUG_ON(!crypt_info->ci_size); if (DUMMY_ENCRYPTION_ENABLED(sbi)) { memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE); diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index d29687c232bd..69faf0e9f874 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -74,7 +74,6 @@ struct ext4_encryption_key { } __attribute__((__packed__)); struct ext4_crypt_info { - unsigned char ci_mode; unsigned char ci_size; char ci_data_mode; char ci_filename_mode; -- cgit v1.2.3-59-g8ed1b From 614def7013574ffcd54019b6df40ac1c0df754af Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 31 May 2015 13:31:34 -0400 Subject: ext4 crypto: shrink size of the ext4_crypto_ctx structure Some fields are only used when the crypto_ctx is being used on the read path, some are only used on the write path, and some are only used when the structure is on free list. Optimize memory use by using a union. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 31 ++++++++++--------------------- fs/ext4/ext4_crypto.h | 21 ++++++++++++++------- fs/ext4/page-io.c | 2 +- fs/ext4/readpage.c | 10 +++++----- 4 files changed, 30 insertions(+), 34 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 9969d054cd88..28a0e4bd91b0 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -71,14 +71,14 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx) { unsigned long flags; - if (ctx->bounce_page) { + if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page) { if (ctx->flags & EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) - __free_page(ctx->bounce_page); + __free_page(ctx->w.bounce_page); else - mempool_free(ctx->bounce_page, ext4_bounce_page_pool); - ctx->bounce_page = NULL; + mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool); } - ctx->control_page = NULL; + ctx->w.bounce_page = NULL; + ctx->w.control_page = NULL; if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) { if (ctx->tfm) crypto_free_tfm(ctx->tfm); @@ -134,6 +134,7 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) } else { ctx->flags &= ~EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL; } + ctx->flags &= ~EXT4_WRITE_PATH_FL; /* Allocate a new Crypto API context if we don't already have * one or if it isn't the right mode. */ @@ -165,10 +166,6 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) } BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_data_mode)); - /* There shouldn't be a bounce page attached to the crypto - * context at this point. */ - BUG_ON(ctx->bounce_page); - out: if (res) { if (!IS_ERR_OR_NULL(ctx)) @@ -189,15 +186,6 @@ void ext4_exit_crypto(void) struct ext4_crypto_ctx *pos, *n; list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) { - if (pos->bounce_page) { - if (pos->flags & - EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) { - __free_page(pos->bounce_page); - } else { - mempool_free(pos->bounce_page, - ext4_bounce_page_pool); - } - } if (pos->tfm) crypto_free_tfm(pos->tfm); kmem_cache_free(ext4_crypto_ctx_cachep, pos); @@ -425,8 +413,9 @@ struct page *ext4_encrypt(struct inode *inode, } else { ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL; } - ctx->bounce_page = ciphertext_page; - ctx->control_page = plaintext_page; + ctx->flags |= EXT4_WRITE_PATH_FL; + ctx->w.bounce_page = ciphertext_page; + ctx->w.control_page = plaintext_page; err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, plaintext_page->index, plaintext_page, ciphertext_page); if (err) { @@ -505,7 +494,7 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex) } else { ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL; } - ctx->bounce_page = ciphertext_page; + ctx->w.bounce_page = ciphertext_page; while (len--) { err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, lblk, diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index 69faf0e9f874..c5258f242215 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -86,16 +86,23 @@ struct ext4_crypt_info { #define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 #define EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002 +#define EXT4_WRITE_PATH_FL 0x00000004 struct ext4_crypto_ctx { struct crypto_tfm *tfm; /* Crypto API context */ - struct page *bounce_page; /* Ciphertext page on write path */ - struct page *control_page; /* Original page on write path */ - struct bio *bio; /* The bio for this context */ - struct work_struct work; /* Work queue for read complete path */ - struct list_head free_list; /* Free list */ - int flags; /* Flags */ - int mode; /* Encryption mode for tfm */ + union { + struct { + struct page *bounce_page; /* Ciphertext page */ + struct page *control_page; /* Original page */ + } w; + struct { + struct bio *bio; + struct work_struct work; + } r; + struct list_head free_list; /* Free list */ + }; + char flags; /* Flags */ + char mode; /* Encryption mode for tfm */ }; struct ext4_completion_result { diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 5765f88b3904..79636e21d3a2 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -84,7 +84,7 @@ static void ext4_finish_bio(struct bio *bio) /* The bounce data pages are unmapped. */ data_page = page; ctx = (struct ext4_crypto_ctx *)page_private(data_page); - page = ctx->control_page; + page = ctx->w.control_page; } #endif diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index 171b9ac4b45e..ec3ef93a52db 100644 --- a/fs/ext4/readpage.c +++ b/fs/ext4/readpage.c @@ -54,8 +54,8 @@ static void completion_pages(struct work_struct *work) { #ifdef CONFIG_EXT4_FS_ENCRYPTION struct ext4_crypto_ctx *ctx = - container_of(work, struct ext4_crypto_ctx, work); - struct bio *bio = ctx->bio; + container_of(work, struct ext4_crypto_ctx, r.work); + struct bio *bio = ctx->r.bio; struct bio_vec *bv; int i; @@ -109,9 +109,9 @@ static void mpage_end_io(struct bio *bio, int err) if (err) { ext4_release_crypto_ctx(ctx); } else { - INIT_WORK(&ctx->work, completion_pages); - ctx->bio = bio; - queue_work(ext4_read_workqueue, &ctx->work); + INIT_WORK(&ctx->r.work, completion_pages); + ctx->r.bio = bio; + queue_work(ext4_read_workqueue, &ctx->r.work); return; } } -- cgit v1.2.3-59-g8ed1b From c936e1ec2879e43599d801dfa6fe58e7ccfee433 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 31 May 2015 13:34:22 -0400 Subject: ext4 crypto: use per-inode tfm structure As suggested by Herbert Xu, we shouldn't allocate a new tfm each time we read or write a page. Instead we can use a single tfm hanging off the inode's crypt_info structure for all of our encryption needs for that inode, since the tfm can be used by multiple crypto requests in parallel. Also use cmpxchg() to avoid races that could result in crypt_info structure getting doubly allocated or doubly freed. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 64 ++--------------------------- fs/ext4/crypto_fname.c | 48 +--------------------- fs/ext4/crypto_key.c | 108 +++++++++++++++++++++++++++++++++++-------------- fs/ext4/dir.c | 3 -- fs/ext4/ext4.h | 5 +-- fs/ext4/ext4_crypto.h | 3 -- fs/ext4/namei.c | 17 ++++---- fs/ext4/super.c | 2 +- fs/ext4/symlink.c | 2 +- 9 files changed, 96 insertions(+), 156 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 28a0e4bd91b0..c3a9b08309db 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -80,8 +80,6 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx) ctx->w.bounce_page = NULL; ctx->w.control_page = NULL; if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) { - if (ctx->tfm) - crypto_free_tfm(ctx->tfm); kmem_cache_free(ext4_crypto_ctx_cachep, ctx); } else { spin_lock_irqsave(&ext4_crypto_ctx_lock, flags); @@ -136,36 +134,6 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) } ctx->flags &= ~EXT4_WRITE_PATH_FL; - /* Allocate a new Crypto API context if we don't already have - * one or if it isn't the right mode. */ - if (ctx->tfm && (ctx->mode != ci->ci_data_mode)) { - crypto_free_tfm(ctx->tfm); - ctx->tfm = NULL; - ctx->mode = EXT4_ENCRYPTION_MODE_INVALID; - } - if (!ctx->tfm) { - switch (ci->ci_data_mode) { - case EXT4_ENCRYPTION_MODE_AES_256_XTS: - ctx->tfm = crypto_ablkcipher_tfm( - crypto_alloc_ablkcipher("xts(aes)", 0, 0)); - break; - case EXT4_ENCRYPTION_MODE_AES_256_GCM: - /* TODO(mhalcrow): AEAD w/ gcm(aes); - * crypto_aead_setauthsize() */ - ctx->tfm = ERR_PTR(-ENOTSUPP); - break; - default: - BUG(); - } - if (IS_ERR_OR_NULL(ctx->tfm)) { - res = PTR_ERR(ctx->tfm); - ctx->tfm = NULL; - goto out; - } - ctx->mode = ci->ci_data_mode; - } - BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_data_mode)); - out: if (res) { if (!IS_ERR_OR_NULL(ctx)) @@ -185,11 +153,8 @@ void ext4_exit_crypto(void) { struct ext4_crypto_ctx *pos, *n; - list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) { - if (pos->tfm) - crypto_free_tfm(pos->tfm); + list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) kmem_cache_free(ext4_crypto_ctx_cachep, pos); - } INIT_LIST_HEAD(&ext4_free_crypto_ctxs); if (ext4_bounce_page_pool) mempool_destroy(ext4_bounce_page_pool); @@ -303,32 +268,11 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, struct ablkcipher_request *req = NULL; DECLARE_EXT4_COMPLETION_RESULT(ecr); struct scatterlist dst, src; - struct ext4_inode_info *ei = EXT4_I(inode); - struct crypto_ablkcipher *atfm = __crypto_ablkcipher_cast(ctx->tfm); + struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; + struct crypto_ablkcipher *tfm = ci->ci_ctfm; int res = 0; - BUG_ON(!ctx->tfm); - BUG_ON(ctx->mode != ei->i_crypt_info->ci_data_mode); - - if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) { - printk_ratelimited(KERN_ERR - "%s: unsupported crypto algorithm: %d\n", - __func__, ctx->mode); - return -ENOTSUPP; - } - - crypto_ablkcipher_clear_flags(atfm, ~0); - crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY); - - res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info->ci_raw, - ei->i_crypt_info->ci_size); - if (res) { - printk_ratelimited(KERN_ERR - "%s: crypto_ablkcipher_setkey() failed\n", - __func__); - return res; - } - req = ablkcipher_request_alloc(atfm, GFP_NOFS); + req = ablkcipher_request_alloc(tfm, GFP_NOFS); if (!req) { printk_ratelimited(KERN_ERR "%s: crypto_request_alloc() failed\n", diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c index e63dd294d7aa..29a2dc9a6f82 100644 --- a/fs/ext4/crypto_fname.c +++ b/fs/ext4/crypto_fname.c @@ -252,52 +252,6 @@ static int digest_decode(const char *src, int len, char *dst) return cp - dst; } -int ext4_setup_fname_crypto(struct inode *inode) -{ - struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_crypt_info *ci = ei->i_crypt_info; - struct crypto_ablkcipher *ctfm; - int res; - - /* Check if the crypto policy is set on the inode */ - res = ext4_encrypted_inode(inode); - if (res == 0) - return 0; - - res = ext4_get_encryption_info(inode); - if (res < 0) - return res; - ci = ei->i_crypt_info; - - if (!ci || ci->ci_ctfm) - return 0; - - if (ci->ci_filename_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) { - printk_once(KERN_WARNING "ext4: unsupported key mode %d\n", - ci->ci_filename_mode); - return -ENOKEY; - } - - ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0); - if (!ctfm || IS_ERR(ctfm)) { - res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; - printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n", - __func__, res); - return res; - } - crypto_ablkcipher_clear_flags(ctfm, ~0); - crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm), - CRYPTO_TFM_REQ_WEAK_KEY); - - res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size); - if (res) { - crypto_free_ablkcipher(ctfm); - return -EIO; - } - ci->ci_ctfm = ctfm; - return 0; -} - /** * ext4_fname_crypto_round_up() - * @@ -449,7 +403,7 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, fname->disk_name.len = iname->len; goto out; } - ret = ext4_setup_fname_crypto(dir); + ret = ext4_get_encryption_info(dir); if (ret) return ret; ci = EXT4_I(dir)->i_crypt_info; diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index 858d7d67a4e1..442d24e8efc0 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -84,20 +84,32 @@ out: return res; } -void ext4_free_encryption_info(struct inode *inode) +void ext4_free_crypt_info(struct ext4_crypt_info *ci) { - struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_crypt_info *ci = ei->i_crypt_info; - if (!ci) return; if (ci->ci_keyring_key) key_put(ci->ci_keyring_key); crypto_free_ablkcipher(ci->ci_ctfm); - memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw)); kmem_cache_free(ext4_crypt_info_cachep, ci); - ei->i_crypt_info = NULL; +} + +void ext4_free_encryption_info(struct inode *inode, + struct ext4_crypt_info *ci) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_crypt_info *prev; + + if (ci == NULL) + ci = ACCESS_ONCE(ei->i_crypt_info); + if (ci == NULL) + return; + prev = cmpxchg(&ei->i_crypt_info, ci, NULL); + if (prev != ci) + return; + + ext4_free_crypt_info(ci); } int _ext4_get_encryption_info(struct inode *inode) @@ -111,6 +123,10 @@ int _ext4_get_encryption_info(struct inode *inode) struct ext4_encryption_context ctx; struct user_key_payload *ukp; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct crypto_ablkcipher *ctfm; + const char *cipher_str; + char raw_key[EXT4_MAX_KEY_SIZE]; + char mode; int res; if (!ext4_read_workqueue) { @@ -119,11 +135,14 @@ int _ext4_get_encryption_info(struct inode *inode) return res; } - if (ei->i_crypt_info) { - if (!ei->i_crypt_info->ci_keyring_key || - key_validate(ei->i_crypt_info->ci_keyring_key) == 0) +retry: + crypt_info = ACCESS_ONCE(ei->i_crypt_info); + if (crypt_info) { + if (!crypt_info->ci_keyring_key || + key_validate(crypt_info->ci_keyring_key) == 0) return 0; - ext4_free_encryption_info(inode); + ext4_free_encryption_info(inode, crypt_info); + goto retry; } res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION, @@ -144,26 +163,37 @@ int _ext4_get_encryption_info(struct inode *inode) if (!crypt_info) return -ENOMEM; - ei->i_crypt_policy_flags = ctx.flags; crypt_info->ci_flags = ctx.flags; crypt_info->ci_data_mode = ctx.contents_encryption_mode; crypt_info->ci_filename_mode = ctx.filenames_encryption_mode; crypt_info->ci_ctfm = NULL; + crypt_info->ci_keyring_key = NULL; memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, sizeof(crypt_info->ci_master_key)); if (S_ISREG(inode->i_mode)) - crypt_info->ci_size = - ext4_encryption_key_size(crypt_info->ci_data_mode); + mode = crypt_info->ci_data_mode; else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) - crypt_info->ci_size = - ext4_encryption_key_size(crypt_info->ci_filename_mode); + mode = crypt_info->ci_filename_mode; else BUG(); - BUG_ON(!crypt_info->ci_size); - if (DUMMY_ENCRYPTION_ENABLED(sbi)) { - memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE); + switch (mode) { + case EXT4_ENCRYPTION_MODE_AES_256_XTS: + cipher_str = "xts(aes)"; + break; + case EXT4_ENCRYPTION_MODE_AES_256_CTS: + cipher_str = "cts(cbc(aes))"; + break; + default: + printk_once(KERN_WARNING + "ext4: unsupported key mode %d (ino %u)\n", + mode, (unsigned) inode->i_ino); + res = -ENOKEY; goto out; } + if (DUMMY_ENCRYPTION_ENABLED(sbi)) { + memset(raw_key, 0x42, EXT4_AES_256_XTS_KEY_SIZE); + goto got_key; + } memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX, EXT4_KEY_DESC_PREFIX_SIZE); sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE, @@ -177,6 +207,7 @@ int _ext4_get_encryption_info(struct inode *inode) keyring_key = NULL; goto out; } + crypt_info->ci_keyring_key = keyring_key; BUG_ON(keyring_key->type != &key_type_logon); ukp = ((struct user_key_payload *)keyring_key->payload.data); if (ukp->datalen != sizeof(struct ext4_encryption_key)) { @@ -188,19 +219,36 @@ int _ext4_get_encryption_info(struct inode *inode) EXT4_KEY_DERIVATION_NONCE_SIZE); BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE); res = ext4_derive_key_aes(ctx.nonce, master_key->raw, - crypt_info->ci_raw); -out: - if (res < 0) { - if (res == -ENOKEY) - res = 0; - kmem_cache_free(ext4_crypt_info_cachep, crypt_info); - } else { - ei->i_crypt_info = crypt_info; - crypt_info->ci_keyring_key = keyring_key; - keyring_key = NULL; + raw_key); +got_key: + ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0); + if (!ctfm || IS_ERR(ctfm)) { + res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; + printk(KERN_DEBUG + "%s: error %d (inode %u) allocating crypto tfm\n", + __func__, res, (unsigned) inode->i_ino); + goto out; + } + crypt_info->ci_ctfm = ctfm; + crypto_ablkcipher_clear_flags(ctfm, ~0); + crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm), + CRYPTO_TFM_REQ_WEAK_KEY); + res = crypto_ablkcipher_setkey(ctfm, raw_key, + ext4_encryption_key_size(mode)); + if (res) + goto out; + memzero_explicit(raw_key, sizeof(raw_key)); + if (cmpxchg(&ei->i_crypt_info, NULL, crypt_info) != NULL) { + ext4_free_crypt_info(crypt_info); + goto retry; } - if (keyring_key) - key_put(keyring_key); + return 0; + +out: + if (res == -ENOKEY) + res = 0; + ext4_free_crypt_info(crypt_info); + memzero_explicit(raw_key, sizeof(raw_key)); return res; } diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 28cb94fbb1c9..e11e6ae26baa 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -133,9 +133,6 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) return err; } - err = ext4_setup_fname_crypto(inode); - if (err) - return err; if (ext4_encrypted_inode(inode)) { err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN, &fname_crypto_str); diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 23e33fb3202e..7435ff2c3efb 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -911,7 +911,6 @@ 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; @@ -2105,7 +2104,6 @@ int ext4_fname_usr_to_disk(struct inode *inode, const struct qstr *iname, struct ext4_str *oname); #ifdef CONFIG_EXT4_FS_ENCRYPTION -int ext4_setup_fname_crypto(struct inode *inode); void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str); int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, int lookup, struct ext4_filename *fname); @@ -2131,7 +2129,8 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { } /* crypto_key.c */ -void ext4_free_encryption_info(struct inode *inode); +void ext4_free_crypt_info(struct ext4_crypt_info *ci); +void ext4_free_encryption_info(struct inode *inode, struct ext4_crypt_info *ci); int _ext4_get_encryption_info(struct inode *inode); #ifdef CONFIG_EXT4_FS_ENCRYPTION diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index c5258f242215..34e0d2455881 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -74,13 +74,11 @@ struct ext4_encryption_key { } __attribute__((__packed__)); struct ext4_crypt_info { - unsigned char ci_size; char ci_data_mode; char ci_filename_mode; char ci_flags; struct crypto_ablkcipher *ci_ctfm; struct key *ci_keyring_key; - char ci_raw[EXT4_MAX_KEY_SIZE]; char ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE]; }; @@ -89,7 +87,6 @@ struct ext4_crypt_info { #define EXT4_WRITE_PATH_FL 0x00000004 struct ext4_crypto_ctx { - struct crypto_tfm *tfm; /* Crypto API context */ union { struct { struct page *bounce_page; /* Ciphertext page */ diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 9bed99fdd81a..6ab50f80964f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -607,11 +607,12 @@ static struct stats dx_show_leaf(struct inode *dir, char *name; struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; - int res; + int res = 0; name = de->name; len = de->name_len; - res = ext4_setup_fname_crypto(dir); + if (ext4_encrypted_inode(inode)) + res = ext4_get_encryption_info(dir); if (res) { printk(KERN_WARNING "Error setting up" " fname crypto: %d\n", res); @@ -953,12 +954,12 @@ static int htree_dirblock_to_tree(struct file *dir_file, EXT4_DIR_REC_LEN(0)); #ifdef CONFIG_EXT4_FS_ENCRYPTION /* Check if the directory is encrypted */ - err = ext4_setup_fname_crypto(dir); - if (err) { - brelse(bh); - return err; - } if (ext4_encrypted_inode(dir)) { + err = ext4_get_encryption_info(dir); + if (err < 0) { + brelse(bh); + return err; + } err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN, &fname_crypto_str); if (err < 0) { @@ -3108,7 +3109,7 @@ static int ext4_symlink(struct inode *dir, err = ext4_inherit_context(dir, inode); if (err) goto err_drop_inode; - err = ext4_setup_fname_crypto(inode); + err = ext4_get_encryption_info(inode); if (err) goto err_drop_inode; istr.name = (const unsigned char *) symname; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index b0bd1c1061b3..56bfc2f25d90 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -959,7 +959,7 @@ void ext4_clear_inode(struct inode *inode) } #ifdef CONFIG_EXT4_FS_ENCRYPTION if (EXT4_I(inode)->i_crypt_info) - ext4_free_encryption_info(inode); + ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info); #endif } diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 32870881188e..68e915aac0fe 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -37,7 +37,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd) if (!ext4_encrypted_inode(inode)) return page_follow_link_light(dentry, nd); - res = ext4_setup_fname_crypto(inode); + res = ext4_get_encryption_info(inode); if (res) return ERR_PTR(res); -- cgit v1.2.3-59-g8ed1b From 3dbb5eb9a3aa04f40e551338eee5e8d06f352fe8 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 3 Jun 2015 09:32:39 -0400 Subject: ext4 crypto: allocate bounce pages using GFP_NOWAIT Previously we allocated bounce pages using a combination of alloc_page() and mempool_alloc() with the __GFP_WAIT bit set. Instead, use mempool_alloc() with GFP_NOWAIT. The mempool_alloc() function will try using alloc_pages() initially, and then only use the mempool reserve of pages if alloc_pages() is unable to fulfill the request. This minimizes the the impact on the mm layer when we need to do a large amount of writeback of encrypted files, as Jaeguk Kim had reported that under a heavy fio workload on a system with restricted amounts memory (which unfortunately, includes many mobile handsets), he had observed the the OOM killer getting triggered several times. Using GFP_NOWAIT If the mempool_alloc() function fails, we will retry the page writeback at a later time; the function of the mempool is to ensure that we can writeback at least 32 pages at a time, so we can more efficiently dispatch I/O under high memory pressure situations. In the future we should make this be a tunable so we can determine the best tradeoff between permanently sequestering memory and the ability to quickly launder pages so we can free up memory quickly when necessary. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 27 ++++++--------------------- fs/ext4/ext4_crypto.h | 3 +-- 2 files changed, 7 insertions(+), 23 deletions(-) (limited to 'fs/ext4/ext4_crypto.h') diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index efcb7c04d172..f5c82e8b7b5c 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -71,12 +71,8 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx) { unsigned long flags; - if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page) { - if (ctx->flags & EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) - __free_page(ctx->w.bounce_page); - else - mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool); - } + if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page) + mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool); ctx->w.bounce_page = NULL; ctx->w.control_page = NULL; if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) { @@ -317,22 +313,11 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx) { - struct page *ciphertext_page = alloc_page(GFP_NOFS); - - if (!ciphertext_page) { - /* This is a potential bottleneck, but at least we'll have - * forward progress. */ - ciphertext_page = mempool_alloc(ext4_bounce_page_pool, - GFP_NOFS); - if (ciphertext_page == NULL) - return ERR_PTR(-ENOMEM); - ctx->flags &= ~EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL; - } else { - ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL; - } + ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, GFP_NOWAIT); + if (ctx->w.bounce_page == NULL) + return ERR_PTR(-ENOMEM); ctx->flags |= EXT4_WRITE_PATH_FL; - ctx->w.bounce_page = ciphertext_page; - return ciphertext_page; + return ctx->w.bounce_page; } /** diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h index 34e0d2455881..ac7d4e813796 100644 --- a/fs/ext4/ext4_crypto.h +++ b/fs/ext4/ext4_crypto.h @@ -83,8 +83,7 @@ struct ext4_crypt_info { }; #define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 -#define EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002 -#define EXT4_WRITE_PATH_FL 0x00000004 +#define EXT4_WRITE_PATH_FL 0x00000002 struct ext4_crypto_ctx { union { -- cgit v1.2.3-59-g8ed1b