From 9c7fb7f7637496e375cec9f56d7e316fb7dbf6c3 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 24 Feb 2023 15:25:03 -0800 Subject: [PATCH 1/4] fs/buffer.c: use b_folio for fscrypt work Use b_folio now that it exists. This removes an unnecessary call to compound_head(). No actual change in behavior. Link: https://lore.kernel.org/r/20230224232503.98372-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 9e1e2add541e0..42cb851d06b50 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -331,8 +331,8 @@ static void decrypt_bh(struct work_struct *work) struct buffer_head *bh = ctx->bh; int err; - err = fscrypt_decrypt_pagecache_blocks(page_folio(bh->b_page), - bh->b_size, bh_offset(bh)); + err = fscrypt_decrypt_pagecache_blocks(bh->b_folio, bh->b_size, + bh_offset(bh)); if (err == 0 && need_fsverity(bh)) { /* * We use different work queues for decryption and for verity From 6f2656eab290f0dd437cd4b2ec956c3519172d3b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lu=C3=ADs=20Henriques?= Date: Thu, 16 Mar 2023 18:14:11 +0000 Subject: [PATCH 2/4] fscrypt: new helper function - fscrypt_prepare_lookup_partial() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces a new helper function which can be used both in lookups and in atomic_open operations by filesystems that want to handle filename encryption and no-key dentries themselves. The reason for this function to be used in atomic open is that this operation can act as a lookup if handed a dentry that is negative. And in this case we may need to set DCACHE_NOKEY_NAME. Signed-off-by: Luís Henriques Tested-by: Xiubo Li Reviewed-by: Xiubo Li [ebiggers: improved the function comment, and moved the function to just below __fscrypt_prepare_lookup()] Link: https://lore.kernel.org/r/20230320220149.21863-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/crypto/hooks.c | 30 ++++++++++++++++++++++++++++++ include/linux/fscrypt.h | 7 +++++++ 2 files changed, 37 insertions(+) diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 7b8c5a1104b58..9151934c50866 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -111,6 +111,36 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, } EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup); +/** + * fscrypt_prepare_lookup_partial() - prepare lookup without filename setup + * @dir: the encrypted directory being searched + * @dentry: the dentry being looked up in @dir + * + * This function should be used by the ->lookup and ->atomic_open methods of + * filesystems that handle filename encryption and no-key name encoding + * themselves and thus can't use fscrypt_prepare_lookup(). Like + * fscrypt_prepare_lookup(), this will try to set up the directory's encryption + * key and will set DCACHE_NOKEY_NAME on the dentry if the key is unavailable. + * However, this function doesn't set up a struct fscrypt_name for the filename. + * + * Return: 0 on success; -errno on error. Note that the encryption key being + * unavailable is not considered an error. It is also not an error if + * the encryption policy is unsupported by this kernel; that is treated + * like the key being unavailable, so that files can still be deleted. + */ +int fscrypt_prepare_lookup_partial(struct inode *dir, struct dentry *dentry) +{ + int err = fscrypt_get_encryption_info(dir, true); + + if (!err && !fscrypt_has_encryption_key(dir)) { + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_NOKEY_NAME; + spin_unlock(&dentry->d_lock); + } + return err; +} +EXPORT_SYMBOL_GPL(fscrypt_prepare_lookup_partial); + int __fscrypt_prepare_readdir(struct inode *dir) { return fscrypt_get_encryption_info(dir, true); diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index e0a49c3125ebc..a69f1302051d3 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -359,6 +359,7 @@ int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry, unsigned int flags); int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, struct fscrypt_name *fname); +int fscrypt_prepare_lookup_partial(struct inode *dir, struct dentry *dentry); int __fscrypt_prepare_readdir(struct inode *dir); int __fscrypt_prepare_setattr(struct dentry *dentry, struct iattr *attr); int fscrypt_prepare_setflags(struct inode *inode, @@ -673,6 +674,12 @@ static inline int __fscrypt_prepare_lookup(struct inode *dir, return -EOPNOTSUPP; } +static inline int fscrypt_prepare_lookup_partial(struct inode *dir, + struct dentry *dentry) +{ + return -EOPNOTSUPP; +} + static inline int __fscrypt_prepare_readdir(struct inode *dir) { return -EOPNOTSUPP; From 41b2ad80fdcaafd42fce173cb95847d0cd8614c2 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 20 Mar 2023 16:39:43 -0700 Subject: [PATCH 3/4] fscrypt: use WARN_ON_ONCE instead of WARN_ON As per Linus's suggestion (https://lore.kernel.org/r/CAHk-=whefxRGyNGzCzG6BVeM=5vnvgb-XhSeFJVxJyAxAF8XRA@mail.gmail.com), use WARN_ON_ONCE instead of WARN_ON. This barely adds any extra overhead, and it makes it so that if any of these ever becomes reachable (they shouldn't, but that's the point), the logs can't be flooded. Link: https://lore.kernel.org/r/20230320233943.73600-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/crypto/bio.c | 6 +++--- fs/crypto/fname.c | 4 ++-- fs/crypto/fscrypt_private.h | 4 ++-- fs/crypto/hkdf.c | 4 ++-- fs/crypto/hooks.c | 2 +- fs/crypto/keyring.c | 14 +++++++------- fs/crypto/keysetup.c | 12 ++++++------ fs/crypto/policy.c | 4 ++-- 8 files changed, 25 insertions(+), 25 deletions(-) diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c index d57d0a020f71c..62e1a3dd83574 100644 --- a/fs/crypto/bio.c +++ b/fs/crypto/bio.c @@ -69,7 +69,7 @@ static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode, pblk << (blockbits - SECTOR_SHIFT); } ret = bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0); - if (WARN_ON(ret != bytes_this_page)) { + if (WARN_ON_ONCE(ret != bytes_this_page)) { err = -EIO; goto out; } @@ -147,7 +147,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, break; } nr_pages = i; - if (WARN_ON(nr_pages <= 0)) + if (WARN_ON_ONCE(nr_pages <= 0)) return -EINVAL; /* This always succeeds since __GFP_DIRECT_RECLAIM is set. */ @@ -170,7 +170,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, offset += blocksize; if (offset == PAGE_SIZE || len == 0) { ret = bio_add_page(bio, pages[i++], offset, 0); - if (WARN_ON(ret != offset)) { + if (WARN_ON_ONCE(ret != offset)) { err = -EIO; goto out; } diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 12bd61d20f694..6eae3f12ad503 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -110,7 +110,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, * Copy the filename to the output buffer for encrypting in-place and * pad it with the needed number of NUL bytes. */ - if (WARN_ON(olen < iname->len)) + if (WARN_ON_ONCE(olen < iname->len)) return -ENOBUFS; memcpy(out, iname->name, iname->len); memset(out + iname->len, 0, olen - iname->len); @@ -570,7 +570,7 @@ u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name) { const struct fscrypt_info *ci = dir->i_crypt_info; - WARN_ON(!ci->ci_dirhash_key_initialized); + WARN_ON_ONCE(!ci->ci_dirhash_key_initialized); return siphash(name->name, name->len, &ci->ci_dirhash_key); } diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 0fec2dfc36ebe..05310aa741fd6 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -101,7 +101,7 @@ static inline const u8 *fscrypt_context_nonce(const union fscrypt_context *ctx) case FSCRYPT_CONTEXT_V2: return ctx->v2.nonce; } - WARN_ON(1); + WARN_ON_ONCE(1); return NULL; } @@ -386,7 +386,7 @@ fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, const u8 *raw_key, const struct fscrypt_info *ci) { - WARN_ON(1); + WARN_ON_ONCE(1); return -EOPNOTSUPP; } diff --git a/fs/crypto/hkdf.c b/fs/crypto/hkdf.c index 7607d18b35fc0..5a384dad2c72f 100644 --- a/fs/crypto/hkdf.c +++ b/fs/crypto/hkdf.c @@ -79,7 +79,7 @@ int fscrypt_init_hkdf(struct fscrypt_hkdf *hkdf, const u8 *master_key, return PTR_ERR(hmac_tfm); } - if (WARN_ON(crypto_shash_digestsize(hmac_tfm) != sizeof(prk))) { + if (WARN_ON_ONCE(crypto_shash_digestsize(hmac_tfm) != sizeof(prk))) { err = -EINVAL; goto err_free_tfm; } @@ -125,7 +125,7 @@ int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context, u8 counter = 1; u8 tmp[HKDF_HASHLEN]; - if (WARN_ON(okmlen > 255 * HKDF_HASHLEN)) + if (WARN_ON_ONCE(okmlen > 255 * HKDF_HASHLEN)) return -EINVAL; desc->tfm = hkdf->hmac_tfm; diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 9151934c50866..9e786ae66a134 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -345,7 +345,7 @@ const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, int err; /* This is for encrypted symlinks only */ - if (WARN_ON(!IS_ENCRYPTED(inode))) + if (WARN_ON_ONCE(!IS_ENCRYPTED(inode))) return ERR_PTR(-EINVAL); /* If the decrypted target is already cached, just return it. */ diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c index 13d336a6cc5da..7cbb1fd872acc 100644 --- a/fs/crypto/keyring.c +++ b/fs/crypto/keyring.c @@ -73,7 +73,7 @@ void fscrypt_put_master_key(struct fscrypt_master_key *mk) * fscrypt_master_key struct itself after an RCU grace period ensures * that concurrent keyring lookups can no longer find it. */ - WARN_ON(refcount_read(&mk->mk_active_refs) != 0); + WARN_ON_ONCE(refcount_read(&mk->mk_active_refs) != 0); key_put(mk->mk_users); mk->mk_users = NULL; call_rcu(&mk->mk_rcu_head, fscrypt_free_master_key); @@ -92,7 +92,7 @@ void fscrypt_put_master_key_activeref(struct super_block *sb, * destroying any subkeys embedded in it. */ - if (WARN_ON(!sb->s_master_keys)) + if (WARN_ON_ONCE(!sb->s_master_keys)) return; spin_lock(&sb->s_master_keys->lock); hlist_del_rcu(&mk->mk_node); @@ -102,8 +102,8 @@ void fscrypt_put_master_key_activeref(struct super_block *sb, * ->mk_active_refs == 0 implies that ->mk_secret is not present and * that ->mk_decrypted_inodes is empty. */ - WARN_ON(is_master_key_secret_present(&mk->mk_secret)); - WARN_ON(!list_empty(&mk->mk_decrypted_inodes)); + WARN_ON_ONCE(is_master_key_secret_present(&mk->mk_secret)); + WARN_ON_ONCE(!list_empty(&mk->mk_decrypted_inodes)); for (i = 0; i <= FSCRYPT_MODE_MAX; i++) { fscrypt_destroy_prepared_key( @@ -237,9 +237,9 @@ void fscrypt_destroy_keyring(struct super_block *sb) * with ->mk_secret. There should be no structural refs * beyond the one associated with the active ref. */ - WARN_ON(refcount_read(&mk->mk_active_refs) != 1); - WARN_ON(refcount_read(&mk->mk_struct_refs) != 1); - WARN_ON(!is_master_key_secret_present(&mk->mk_secret)); + WARN_ON_ONCE(refcount_read(&mk->mk_active_refs) != 1); + WARN_ON_ONCE(refcount_read(&mk->mk_struct_refs) != 1); + WARN_ON_ONCE(!is_master_key_secret_present(&mk->mk_secret)); wipe_master_key_secret(&mk->mk_secret); fscrypt_put_master_key_activeref(sb, mk); } diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index aa94fba9d17e7..84cdae3063280 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -125,7 +125,7 @@ fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key, pr_info("fscrypt: %s using implementation \"%s\"\n", mode->friendly_name, crypto_skcipher_driver_name(tfm)); } - if (WARN_ON(crypto_skcipher_ivsize(tfm) != mode->ivsize)) { + if (WARN_ON_ONCE(crypto_skcipher_ivsize(tfm) != mode->ivsize)) { err = -EINVAL; goto err_free_tfm; } @@ -199,7 +199,7 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci, unsigned int hkdf_infolen = 0; int err; - if (WARN_ON(mode_num > FSCRYPT_MODE_MAX)) + if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX)) return -EINVAL; prep_key = &keys[mode_num]; @@ -282,8 +282,8 @@ int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, void fscrypt_hash_inode_number(struct fscrypt_info *ci, const struct fscrypt_master_key *mk) { - WARN_ON(ci->ci_inode->i_ino == 0); - WARN_ON(!mk->mk_ino_hash_key_initialized); + WARN_ON_ONCE(ci->ci_inode->i_ino == 0); + WARN_ON_ONCE(!mk->mk_ino_hash_key_initialized); ci->ci_hashed_ino = (u32)siphash_1u64(ci->ci_inode->i_ino, &mk->mk_ino_hash_key); @@ -503,7 +503,7 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, err = fscrypt_setup_v2_file_key(ci, mk, need_dirhash_key); break; default: - WARN_ON(1); + WARN_ON_ONCE(1); err = -EINVAL; break; } @@ -577,7 +577,7 @@ fscrypt_setup_encryption_info(struct inode *inode, res = PTR_ERR(mode); goto out; } - WARN_ON(mode->ivsize > FSCRYPT_MAX_IV_SIZE); + WARN_ON_ONCE(mode->ivsize > FSCRYPT_MAX_IV_SIZE); crypt_info->ci_mode = mode; res = setup_file_encryption_key(crypt_info, need_dirhash_key, &mk); diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 3b5fcb6402eae..f4456ecb3f877 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -48,7 +48,7 @@ int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy, FSCRYPT_KEY_IDENTIFIER_SIZE); return 0; default: - WARN_ON(1); + WARN_ON_ONCE(1); return -EINVAL; } } @@ -463,7 +463,7 @@ static int set_encryption_policy(struct inode *inode, current->comm, current->pid); break; default: - WARN_ON(1); + WARN_ON_ONCE(1); return -EINVAL; } From 83e57e47906ce0e99bd61c70fae514e69960d274 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 6 Apr 2023 11:12:45 -0700 Subject: [PATCH 4/4] fscrypt: optimize fscrypt_initialize() fscrypt_initialize() is a "one-time init" function that is called whenever the key is set up for any inode on any filesystem. Make it implement "one-time init" more efficiently by not taking a global mutex in the "already initialized case" and doing fewer pointer dereferences. Link: https://lore.kernel.org/r/20230406181245.36091-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/crypto/crypto.c | 19 ++++++++++++------- fs/crypto/fscrypt_private.h | 2 +- fs/crypto/keysetup.c | 2 +- 3 files changed, 14 insertions(+), 9 deletions(-) diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index bf642479269a5..6a837e4b80dcb 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -308,19 +308,24 @@ EXPORT_SYMBOL(fscrypt_decrypt_block_inplace); /** * fscrypt_initialize() - allocate major buffers for fs encryption. - * @cop_flags: fscrypt operations flags + * @sb: the filesystem superblock * * We only call this when we start accessing encrypted files, since it * results in memory getting allocated that wouldn't otherwise be used. * * Return: 0 on success; -errno on failure */ -int fscrypt_initialize(unsigned int cop_flags) +int fscrypt_initialize(struct super_block *sb) { int err = 0; + mempool_t *pool; + + /* pairs with smp_store_release() below */ + if (likely(smp_load_acquire(&fscrypt_bounce_page_pool))) + return 0; /* No need to allocate a bounce page pool if this FS won't use it. */ - if (cop_flags & FS_CFLG_OWN_PAGES) + if (sb->s_cop->flags & FS_CFLG_OWN_PAGES) return 0; mutex_lock(&fscrypt_init_mutex); @@ -328,11 +333,11 @@ int fscrypt_initialize(unsigned int cop_flags) goto out_unlock; err = -ENOMEM; - fscrypt_bounce_page_pool = - mempool_create_page_pool(num_prealloc_crypto_pages, 0); - if (!fscrypt_bounce_page_pool) + pool = mempool_create_page_pool(num_prealloc_crypto_pages, 0); + if (!pool) goto out_unlock; - + /* pairs with smp_load_acquire() above */ + smp_store_release(&fscrypt_bounce_page_pool, pool); err = 0; out_unlock: mutex_unlock(&fscrypt_init_mutex); diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 05310aa741fd6..7ab5a7b7eef8c 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -264,7 +264,7 @@ typedef enum { /* crypto.c */ extern struct kmem_cache *fscrypt_info_cachep; -int fscrypt_initialize(unsigned int cop_flags); +int fscrypt_initialize(struct super_block *sb); int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, u64 lblk_num, struct page *src_page, struct page *dest_page, unsigned int len, diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 84cdae3063280..361f41ef46c78 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -560,7 +560,7 @@ fscrypt_setup_encryption_info(struct inode *inode, struct fscrypt_master_key *mk = NULL; int res; - res = fscrypt_initialize(inode->i_sb->s_cop->flags); + res = fscrypt_initialize(inode->i_sb); if (res) return res;