diff options
Diffstat (limited to 'fs/crypto/crypto.c')
| -rw-r--r-- | fs/crypto/crypto.c | 57 |
1 files changed, 6 insertions, 51 deletions
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 3719efa546c6..1ecaac7ee3cb 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -25,8 +25,6 @@ #include <linux/module.h> #include <linux/scatterlist.h> #include <linux/ratelimit.h> -#include <linux/dcache.h> -#include <linux/namei.h> #include <crypto/skcipher.h> #include "fscrypt_private.h" @@ -140,7 +138,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, * multiple of the filesystem's block size. * @offs: Byte offset within @page of the first block to encrypt. Must be * a multiple of the filesystem's block size. - * @gfp_flags: Memory allocation flags + * @gfp_flags: Memory allocation flags. See details below. * * A new bounce page is allocated, and the specified block(s) are encrypted into * it. In the bounce page, the ciphertext block(s) will be located at the same @@ -150,6 +148,11 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, * * This is for use by the filesystem's ->writepages() method. * + * The bounce page allocation is mempool-backed, so it will always succeed when + * @gfp_flags includes __GFP_DIRECT_RECLAIM, e.g. when it's GFP_NOFS. However, + * only the first page of each bio can be allocated this way. To prevent + * deadlocks, for any additional pages a mask like GFP_NOWAIT must be used. + * * Return: the new encrypted bounce page on success; an ERR_PTR() on failure */ struct page *fscrypt_encrypt_pagecache_blocks(struct page *page, @@ -286,54 +289,6 @@ int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page, } EXPORT_SYMBOL(fscrypt_decrypt_block_inplace); -/* - * Validate dentries in encrypted directories to make sure we aren't potentially - * caching stale dentries after a key has been added. - */ -static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags) -{ - struct dentry *dir; - int err; - int valid; - - /* - * Plaintext names are always valid, since fscrypt doesn't support - * reverting to ciphertext names without evicting the directory's inode - * -- which implies eviction of the dentries in the directory. - */ - if (!(dentry->d_flags & DCACHE_ENCRYPTED_NAME)) - return 1; - - /* - * Ciphertext name; valid if the directory's key is still unavailable. - * - * Although fscrypt forbids rename() on ciphertext names, we still must - * use dget_parent() here rather than use ->d_parent directly. That's - * because a corrupted fs image may contain directory hard links, which - * the VFS handles by moving the directory's dentry tree in the dcache - * each time ->lookup() finds the directory and it already has a dentry - * elsewhere. Thus ->d_parent can be changing, and we must safely grab - * a reference to some ->d_parent to prevent it from being freed. - */ - - if (flags & LOOKUP_RCU) - return -ECHILD; - - dir = dget_parent(dentry); - err = fscrypt_get_encryption_info(d_inode(dir)); - valid = !fscrypt_has_encryption_key(d_inode(dir)); - dput(dir); - - if (err < 0) - return err; - - return valid; -} - -const struct dentry_operations fscrypt_d_ops = { - .d_revalidate = fscrypt_d_revalidate, -}; - /** * fscrypt_initialize() - allocate major buffers for fs encryption. * @cop_flags: fscrypt operations flags |