From patchwork Fri Jan 17 21:42:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Rosenberg X-Patchwork-Id: 11339881 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6FB6517EA for ; Fri, 17 Jan 2020 21:43:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4EAB62072B for ; Fri, 17 Jan 2020 21:43:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="re88JEJx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729836AbgAQVnK (ORCPT ); Fri, 17 Jan 2020 16:43:10 -0500 Received: from mail-pj1-f74.google.com ([209.85.216.74]:40533 "EHLO mail-pj1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729822AbgAQVnI (ORCPT ); Fri, 17 Jan 2020 16:43:08 -0500 Received: by mail-pj1-f74.google.com with SMTP id g12so5293170pje.5 for ; Fri, 17 Jan 2020 13:43:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=kB+NQKJiUAIRFl4aTji9u2bg8hO9+Q8WB3NnVD/VOa0=; b=re88JEJxDhwb7zLLnErnvZM02G0Gj4vQuRSRgAHJ0gPpq11nzY7dKVshwiMI8iTL7T 3hafAtjrYmHUaz5W2zGiRx84jD5Ff8W/hqL22aIB2sf5WjtIavPyHTZYDuGbhFal1VWr W2GR9e4ggOxjGg6Rdd6Ljz2n00RFUUNLwkGxlDSy5A9n8Itru3wF8riUuhmcbmhEwjSJ Ov7T0tQyORgBVk/nOhN75kRaxfBqppX/4cDjvHcSsHBnp2AyrFW5xMrWMzGKwHsRtu2X v9RZ5r6aQF9u7NS41DNZsV/IW1wwkGCvWcAtObe3V0kRAVe9Dk3HqdhGNGXjmYqPtfR9 BthA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=kB+NQKJiUAIRFl4aTji9u2bg8hO9+Q8WB3NnVD/VOa0=; b=LcHs1q3Y5bK7PK+Hv+3HBfTE84kMYWpNHcvYtEZDMNo3ScAXq6Pi0iU0jcHHcVTu94 OelF4aJPAii1vm3rnK0amjarHGDYEy+XYQypOpRNFfboiAR18zOwvqdtGBQ97pJOGkEn kRkTg3TIfoRJ4FAxcAbr2eqW2Ud5VVVzhuTPJWN2SBw6cQqI+B6OEw/ll1EaNn+kT605 KwrI5nFu1bI5FPBYbBiwHVCO6lZuZChGWic/kofTpXd1ZN6RfOr9aIGV7ttVlaXnuMB/ fKFclH5+BH1xbKy+16Bq3AT43ioMy4wrBQ/UZEanG0nJ6DR7cFmnZ1hMqtkndOKM9UHH 6CxA== X-Gm-Message-State: APjAAAWVlurdts5SaNsdBI2Xxgc1KHDfCkmCMkf5vlfa2gX5hQED08w/ KchVTF9sxSBMfzKHNURyhEySKp1mg+o= X-Google-Smtp-Source: APXvYqw6Ct56QGUI/qT+gtMlJeOAmF7SuNqwoG6m8v2zpcXR33XO9wzdYHdjMiRNIInMZ2yefbbvYg8zvuM= X-Received: by 2002:a65:46c6:: with SMTP id n6mr47933917pgr.15.1579297387762; Fri, 17 Jan 2020 13:43:07 -0800 (PST) Date: Fri, 17 Jan 2020 13:42:42 -0800 In-Reply-To: <20200117214246.235591-1-drosen@google.com> Message-Id: <20200117214246.235591-6-drosen@google.com> Mime-Version: 1.0 References: <20200117214246.235591-1-drosen@google.com> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog Subject: [PATCH v3 5/9] vfs: Fold casefolding into vfs From: Daniel Rosenberg To: "Theodore Ts'o" , linux-ext4@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net, Eric Biggers , linux-fscrypt@vger.kernel.org, Alexander Viro Cc: Andreas Dilger , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Gabriel Krisman Bertazi , kernel-team@android.com, Daniel Rosenberg Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Ext4 and F2fs are both using casefolding, and they, along with any other filesystem that adds the feature, will be using identical dentry_ops. Additionally, those dentry ops interfere with the dentry_ops required for fscrypt once we add support for casefolding and encryption. Moving this into the vfs removes code duplication as well as the complication with encryption. Currently this is pretty close to just moving the existing f2fs/ext4 code up a level into the vfs, although there is a lot of room for improvement now. Signed-off-by: Daniel Rosenberg --- fs/dcache.c | 28 ++++++++++++++++++++++++++++ fs/namei.c | 41 ++++++++++++++++++++++++++++++++++++++--- include/linux/fs.h | 10 ++++++++++ include/linux/unicode.h | 14 ++++++++++++++ 4 files changed, 90 insertions(+), 3 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index b280e07e162b1..a8bbb7f4fad30 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "internal.h" #include "mount.h" @@ -247,7 +248,19 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c * be no NUL in the ct/tcount data) */ const unsigned char *cs = READ_ONCE(dentry->d_name.name); +#ifdef CONFIG_UNICODE + struct inode *parent = dentry->d_parent->d_inode; + if (unlikely(needs_casefold(parent))) { + const struct qstr n1 = QSTR_INIT(cs, tcount); + const struct qstr n2 = QSTR_INIT(ct, tcount); + int result = utf8_strncasecmp(dentry->d_sb->s_encoding, + &n1, &n2); + + if (result >= 0 || sb_has_enc_strict_mode(dentry->d_sb)) + return result; + } +#endif return dentry_string_cmp(cs, ct, tcount); } @@ -2406,7 +2419,22 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name) * calculate the standard hash first, as the d_op->d_hash() * routine may choose to leave the hash value unchanged. */ +#ifdef CONFIG_UNICODE + unsigned char *hname = NULL; + int hlen = name->len; + + if (IS_CASEFOLDED(dir->d_inode)) { + hname = kmalloc(PATH_MAX, GFP_ATOMIC); + if (!hname) + return ERR_PTR(-ENOMEM); + hlen = utf8_casefold(dir->d_sb->s_encoding, + name, hname, PATH_MAX); + } + name->hash = full_name_hash(dir, hname ?: name->name, hlen); + kfree(hname); +#else name->hash = full_name_hash(dir, name->name, name->len); +#endif if (dir->d_flags & DCACHE_OP_HASH) { int err = dir->d_op->d_hash(dir, name); if (unlikely(err < 0)) diff --git a/fs/namei.c b/fs/namei.c index d6c91d1e88cb3..f8e65c9f31444 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -39,6 +39,7 @@ #include #include #include +#include #include "internal.h" #include "mount.h" @@ -2055,6 +2056,10 @@ static inline u64 hash_name(const void *salt, const char *name) static int link_path_walk(const char *name, struct nameidata *nd) { int err; +#ifdef CONFIG_UNICODE + char *hname = NULL; + int hlen = 0; +#endif if (IS_ERR(name)) return PTR_ERR(name); @@ -2071,9 +2076,22 @@ static int link_path_walk(const char *name, struct nameidata *nd) err = may_lookup(nd); if (err) return err; - +#ifdef CONFIG_UNICODE + if (needs_casefold(nd->path.dentry->d_inode)) { + struct qstr str = QSTR_INIT(name, PATH_MAX); + + hname = kmalloc(PATH_MAX, GFP_ATOMIC); + if (!hname) + return -ENOMEM; + hlen = utf8_casefold(nd->path.dentry->d_sb->s_encoding, + &str, hname, PATH_MAX); + } + hash_len = hash_name(nd->path.dentry, hname ?: name); + kfree(hname); + hname = NULL; +#else hash_len = hash_name(nd->path.dentry, name); - +#endif type = LAST_NORM; if (name[0] == '.') switch (hashlen_len(hash_len)) { case 2: @@ -2445,9 +2463,26 @@ EXPORT_SYMBOL(vfs_path_lookup); static int lookup_one_len_common(const char *name, struct dentry *base, int len, struct qstr *this) { +#ifdef CONFIG_UNICODE + char *hname = NULL; + int hlen = len; + + if (needs_casefold(base->d_inode)) { + struct qstr str = QSTR_INIT(name, len); + + hname = kmalloc(PATH_MAX, GFP_ATOMIC); + if (!hname) + return -ENOMEM; + hlen = utf8_casefold(base->d_sb->s_encoding, + &str, hname, PATH_MAX); + } + this->hash = full_name_hash(base, hname ?: name, hlen); + kfree(hname); +#else + this->hash = full_name_hash(base, name, len); +#endif this->name = name; this->len = len; - this->hash = full_name_hash(base, name, len); if (!len) return -EACCES; diff --git a/include/linux/fs.h b/include/linux/fs.h index 98e0349adb526..9a7092449e94f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1382,6 +1382,12 @@ extern int send_sigurg(struct fown_struct *fown); #define SB_ACTIVE (1<<30) #define SB_NOUSER (1<<31) +/* These flags relate to encoding and casefolding */ +#define SB_ENC_STRICT_MODE_FL (1 << 0) + +#define sb_has_enc_strict_mode(sb) \ + (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL) + /* * Umount options */ @@ -1449,6 +1455,10 @@ struct super_block { #endif #ifdef CONFIG_FS_VERITY const struct fsverity_operations *s_vop; +#endif +#ifdef CONFIG_UNICODE + struct unicode_map *s_encoding; + __u16 s_encoding_flags; #endif struct hlist_bl_head s_roots; /* alternate root dentries for NFS */ struct list_head s_mounts; /* list of mounts; _not_ for fs use */ diff --git a/include/linux/unicode.h b/include/linux/unicode.h index 990aa97d80496..182352f3cc30f 100644 --- a/include/linux/unicode.h +++ b/include/linux/unicode.h @@ -4,6 +4,8 @@ #include #include +#include +#include struct unicode_map { const char *charset; @@ -30,4 +32,16 @@ int utf8_casefold(const struct unicode_map *um, const struct qstr *str, struct unicode_map *utf8_load(const char *version); void utf8_unload(struct unicode_map *um); +#ifdef CONFIG_UNICODE +static inline bool needs_casefold(const struct inode *dir) +{ + return IS_CASEFOLDED(dir) && dir->i_sb->s_encoding && + (!IS_ENCRYPTED(dir) || fscrypt_has_encryption_key(dir)); +} +#else +static inline bool needs_casefold(const struct inode *dir) +{ + return 0; +} +#endif #endif /* _LINUX_UNICODE_H */