From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FA31C76194 for ; Thu, 25 Jul 2019 09:58:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32FA520840 for ; Thu, 25 Jul 2019 09:58:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729726AbfGYJ6r (ORCPT ); Thu, 25 Jul 2019 05:58:47 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:56086 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2391043AbfGYJ5f (ORCPT ); Thu, 25 Jul 2019 05:57:35 -0400 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id A640F834E0CEB30820D3; Thu, 25 Jul 2019 17:57:31 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.210) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 25 Jul 2019 17:57:25 +0800 From: Gao Xiang To: Alexander Viro , Greg Kroah-Hartman , Andrew Morton , Stephen Rothwell , Theodore Ts'o , "David Sterba" , Amir Goldstein , Linus Torvalds CC: , , LKML , , Chao Yu , Miao Xie , Li Guifu , Fang Wei , Gao Xiang Subject: [PATCH v4 11/24] erofs: introduce xattr & posixacl support Date: Thu, 25 Jul 2019 17:56:45 +0800 Message-ID: <20190725095658.155779-12-gaoxiang25@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190725095658.155779-1-gaoxiang25@huawei.com> References: <20190725095658.155779-1-gaoxiang25@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.140.130.215] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This implements xattr and posixacl functionalities. 1) Inline and shared xattrs are introduced for flexibility. Specifically, if the same xattr is used for a large number of inodes or the size of a xattr is so large that unsuitable to inline, a shared xattr will be used instead in xattr meta. 2) Add .get_acl() to read the file's acl from its xattrs to make POSIX ACL usable. Here is the on-disk detail, fullname: system.posix_acl_access struct erofs_xattr_entry: .e_name_len = 0 .e_name_index = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS (2) fullname: system.posix_acl_default struct erofs_xattr_entry: .e_name_len = 0 .e_name_index = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT (3) Signed-off-by: Gao Xiang --- fs/erofs/Kconfig | 38 +++ fs/erofs/Makefile | 1 + fs/erofs/inode.c | 14 +- fs/erofs/internal.h | 16 + fs/erofs/namei.c | 6 +- fs/erofs/super.c | 77 ++++- fs/erofs/xattr.c | 700 ++++++++++++++++++++++++++++++++++++++++++++ fs/erofs/xattr.h | 93 ++++++ 8 files changed, 942 insertions(+), 3 deletions(-) create mode 100644 fs/erofs/xattr.c create mode 100644 fs/erofs/xattr.h diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index 98f05043448a..c5e7c5ae026e 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -34,3 +34,41 @@ config EROFS_FAULT_INJECTION Test EROFS to inject faults such as ENOMEM, EIO, and so on. If unsure, say N. +config EROFS_FS_XATTR + bool "EROFS extended attributes" + depends on EROFS_FS + default y + help + Extended attributes are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page, or visit + for details). + + If unsure, say N. + +config EROFS_FS_POSIX_ACL + bool "EROFS Access Control Lists" + depends on EROFS_FS_XATTR + select FS_POSIX_ACL + default y + help + Posix Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + To learn more about Access Control Lists, visit the POSIX ACLs for + Linux website . + + If you don't know what Access Control Lists are, say N. + +config EROFS_FS_SECURITY + bool "EROFS Security Labels" + depends on EROFS_FS_XATTR + default y + help + Security labels provide an access control facility to support Linux + Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO + Linux. This option enables an extended attribute handler for file + security labels in the erofs filesystem, so that it requires enabling + the extended attribute support in advance. + + If you are not using a security module, say N. + diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile index c3f4e549ef90..190a73083f23 100644 --- a/fs/erofs/Makefile +++ b/fs/erofs/Makefile @@ -6,4 +6,5 @@ ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\" obj-$(CONFIG_EROFS_FS) += erofs.o erofs-objs := super.o inode.o data.o namei.o dir.o +erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index 637bf6e4de44..aee53988aef5 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -6,7 +6,7 @@ * http://www.huawei.com/ * Created by Gao Xiang */ -#include "internal.h" +#include "xattr.h" #include @@ -300,15 +300,27 @@ int erofs_getattr(const struct path *path, struct kstat *stat, const struct inode_operations erofs_generic_iops = { .getattr = erofs_getattr, +#ifdef CONFIG_EROFS_FS_XATTR + .listxattr = erofs_listxattr, +#endif + .get_acl = erofs_get_acl, }; const struct inode_operations erofs_symlink_iops = { .get_link = page_get_link, .getattr = erofs_getattr, +#ifdef CONFIG_EROFS_FS_XATTR + .listxattr = erofs_listxattr, +#endif + .get_acl = erofs_get_acl, }; const struct inode_operations erofs_fast_symlink_iops = { .get_link = simple_get_link, .getattr = erofs_getattr, +#ifdef CONFIG_EROFS_FS_XATTR + .listxattr = erofs_listxattr, +#endif + .get_acl = erofs_get_acl, }; diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 8e47ca55d572..10e72cf1ab65 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -63,6 +63,9 @@ typedef u32 erofs_blk_t; struct erofs_sb_info { u32 blocks; u32 meta_blkaddr; +#ifdef CONFIG_EROFS_FS_XATTR + u32 xattr_blkaddr; +#endif /* inode slot unit size in bit shift */ unsigned char islotbits; @@ -132,6 +135,8 @@ static inline void *erofs_kmalloc(struct erofs_sb_info *sbi, #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info) /* Mount flags set via mount options or defaults */ +#define EROFS_MOUNT_XATTR_USER 0x00000010 +#define EROFS_MOUNT_POSIX_ACL 0x00000020 #define EROFS_MOUNT_FAULT_INJECTION 0x00000040 #define clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option) @@ -166,13 +171,24 @@ static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid) return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits); } +/* atomic flag definitions */ +#define EROFS_V_EA_INITED_BIT 0 + +/* bitlock definitions (arranged in reverse order) */ +#define EROFS_V_BL_XATTR_BIT (BITS_PER_LONG - 1) struct erofs_vnode { erofs_nid_t nid; + /* atomic flags (including bitlocks) */ + unsigned long flags; + unsigned char datamode; unsigned char inode_isize; unsigned short xattr_isize; + unsigned int xattr_shared_count; + unsigned int *xattr_shared_xattrs; + erofs_blk_t raw_blkaddr; /* the corresponding vfs inode */ struct inode vfs_inode; diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c index 9620dd602317..fead01f65f91 100644 --- a/fs/erofs/namei.c +++ b/fs/erofs/namei.c @@ -6,7 +6,7 @@ * http://www.huawei.com/ * Created by Gao Xiang */ -#include "internal.h" +#include "xattr.h" #include @@ -242,5 +242,9 @@ static struct dentry *erofs_lookup(struct inode *dir, const struct inode_operations erofs_dir_iops = { .lookup = erofs_lookup, .getattr = erofs_getattr, +#ifdef CONFIG_EROFS_FS_XATTR + .listxattr = erofs_listxattr, +#endif + .get_acl = erofs_get_acl, }; diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 3f1096b368f3..9b040be8c607 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -11,7 +11,7 @@ #include #include #include -#include "internal.h" +#include "xattr.h" #define CREATE_TRACE_POINTS #include @@ -61,6 +61,8 @@ static void free_inode(struct inode *inode) if (is_inode_fast_symlink(inode)) kfree(inode->i_link); + kfree(vi->xattr_shared_xattrs); + kmem_cache_free(erofs_inode_cachep, vi); } @@ -118,6 +120,9 @@ static int superblock_read(struct super_block *sb) sbi->blocks = le32_to_cpu(layout->blocks); sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr); +#ifdef CONFIG_EROFS_FS_XATTR + sbi->xattr_blkaddr = le32_to_cpu(layout->xattr_blkaddr); +#endif sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1; sbi->root_nid = le16_to_cpu(layout->root_nid); sbi->inos = le64_to_cpu(layout->inos); @@ -195,14 +200,28 @@ static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi) /* set up default EROFS parameters */ static void default_options(struct erofs_sb_info *sbi) { +#ifdef CONFIG_EROFS_FS_XATTR + set_opt(sbi, XATTR_USER); +#endif +#ifdef CONFIG_EROFS_FS_POSIX_ACL + set_opt(sbi, POSIX_ACL); +#endif } enum { + Opt_user_xattr, + Opt_nouser_xattr, + Opt_acl, + Opt_noacl, Opt_fault_injection, Opt_err }; static match_table_t erofs_tokens = { + {Opt_user_xattr, "user_xattr"}, + {Opt_nouser_xattr, "nouser_xattr"}, + {Opt_acl, "acl"}, + {Opt_noacl, "noacl"}, {Opt_fault_injection, "fault_injection=%u"}, {Opt_err, NULL} }; @@ -226,6 +245,36 @@ static int parse_options(struct super_block *sb, char *options) token = match_token(p, erofs_tokens, args); switch (token) { +#ifdef CONFIG_EROFS_FS_XATTR + case Opt_user_xattr: + set_opt(EROFS_SB(sb), XATTR_USER); + break; + case Opt_nouser_xattr: + clear_opt(EROFS_SB(sb), XATTR_USER); + break; +#else + case Opt_user_xattr: + infoln("user_xattr options not supported"); + break; + case Opt_nouser_xattr: + infoln("nouser_xattr options not supported"); + break; +#endif +#ifdef CONFIG_EROFS_FS_POSIX_ACL + case Opt_acl: + set_opt(EROFS_SB(sb), POSIX_ACL); + break; + case Opt_noacl: + clear_opt(EROFS_SB(sb), POSIX_ACL); + break; +#else + case Opt_acl: + infoln("acl options not supported"); + break; + case Opt_noacl: + infoln("noacl options not supported"); + break; +#endif case Opt_fault_injection: err = erofs_build_fault_attr(EROFS_SB(sb), args); if (err) @@ -270,6 +319,10 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent) sb->s_op = &erofs_sops; +#ifdef CONFIG_EROFS_FS_XATTR + sb->s_xattr = erofs_xattr_handlers; +#endif + /* set erofs default mount options */ default_options(sbi); @@ -280,6 +333,11 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent) if (!silent) infoln("root inode @ nid %llu", ROOT_NID(sbi)); + if (test_opt(sbi, POSIX_ACL)) + sb->s_flags |= SB_POSIXACL; + else + sb->s_flags &= ~SB_POSIXACL; + /* get the root inode */ inode = erofs_iget(sb, ROOT_NID(sbi), true); if (IS_ERR(inode)) @@ -393,6 +451,18 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root) { struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb); +#ifdef CONFIG_EROFS_FS_XATTR + if (test_opt(sbi, XATTR_USER)) + seq_puts(seq, ",user_xattr"); + else + seq_puts(seq, ",nouser_xattr"); +#endif +#ifdef CONFIG_EROFS_FS_POSIX_ACL + if (test_opt(sbi, POSIX_ACL)) + seq_puts(seq, ",acl"); + else + seq_puts(seq, ",noacl"); +#endif if (test_opt(sbi, FAULT_INJECTION)) seq_printf(seq, ",fault_injection=%u", erofs_get_fault_rate(sbi)); @@ -411,6 +481,11 @@ static int erofs_remount(struct super_block *sb, int *flags, char *data) if (err) goto out; + if (test_opt(sbi, POSIX_ACL)) + sb->s_flags |= SB_POSIXACL; + else + sb->s_flags &= ~SB_POSIXACL; + *flags |= SB_RDONLY; return 0; out: diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c new file mode 100644 index 000000000000..148ceaf72790 --- /dev/null +++ b/fs/erofs/xattr.c @@ -0,0 +1,700 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/erofs/xattr.c + * + * Copyright (C) 2017-2018 HUAWEI, Inc. + * http://www.huawei.com/ + * Created by Gao Xiang + */ +#include +#include "xattr.h" + +struct xattr_iter { + struct super_block *sb; + struct page *page; + void *kaddr; + + erofs_blk_t blkaddr; + unsigned int ofs; +}; + +static inline void xattr_iter_end(struct xattr_iter *it, bool atomic) +{ + /* the only user of kunmap() is 'init_inode_xattrs' */ + if (unlikely(!atomic)) + kunmap(it->page); + else + kunmap_atomic(it->kaddr); + + unlock_page(it->page); + put_page(it->page); +} + +static inline void xattr_iter_end_final(struct xattr_iter *it) +{ + if (!it->page) + return; + + xattr_iter_end(it, true); +} + +static int init_inode_xattrs(struct inode *inode) +{ + struct erofs_vnode *const vi = EROFS_V(inode); + struct xattr_iter it; + unsigned int i; + struct erofs_xattr_ibody_header *ih; + struct super_block *sb; + struct erofs_sb_info *sbi; + bool atomic_map; + int ret = 0; + + /* the most case is that xattrs of this inode are initialized. */ + if (test_bit(EROFS_V_EA_INITED_BIT, &vi->flags)) + return 0; + + if (wait_on_bit_lock(&vi->flags, EROFS_V_BL_XATTR_BIT, TASK_KILLABLE)) + return -ERESTARTSYS; + + /* someone has initialized xattrs for us? */ + if (test_bit(EROFS_V_EA_INITED_BIT, &vi->flags)) + goto out_unlock; + + /* + * bypass all xattr operations if ->xattr_isize is not greater than + * sizeof(struct erofs_xattr_ibody_header), in detail: + * 1) it is not enough to contain erofs_xattr_ibody_header then + * ->xattr_isize should be 0 (it means no xattr); + * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk + * undefined right now (maybe use later with some new sb feature). + */ + if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) { + errln("xattr_isize %d of nid %llu is not supported yet", + vi->xattr_isize, vi->nid); + ret = -ENOTSUPP; + goto out_unlock; + } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) { + if (unlikely(vi->xattr_isize)) { + DBG_BUGON(1); + ret = -EIO; + goto out_unlock; /* xattr ondisk layout error */ + } + ret = -ENOATTR; + goto out_unlock; + } + + sb = inode->i_sb; + sbi = EROFS_SB(sb); + it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize); + it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize); + + it.page = erofs_get_inline_page(inode, it.blkaddr); + if (IS_ERR(it.page)) { + ret = PTR_ERR(it.page); + goto out_unlock; + } + + /* read in shared xattr array (non-atomic, see kmalloc below) */ + it.kaddr = kmap(it.page); + atomic_map = false; + + ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs); + + vi->xattr_shared_count = ih->h_shared_count; + vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, + sizeof(uint), GFP_KERNEL); + if (!vi->xattr_shared_xattrs) { + xattr_iter_end(&it, atomic_map); + ret = -ENOMEM; + goto out_unlock; + } + + /* let's skip ibody header */ + it.ofs += sizeof(struct erofs_xattr_ibody_header); + + for (i = 0; i < vi->xattr_shared_count; ++i) { + if (unlikely(it.ofs >= EROFS_BLKSIZ)) { + /* cannot be unaligned */ + BUG_ON(it.ofs != EROFS_BLKSIZ); + xattr_iter_end(&it, atomic_map); + + it.page = erofs_get_meta_page(sb, ++it.blkaddr, + S_ISDIR(inode->i_mode)); + if (IS_ERR(it.page)) { + kfree(vi->xattr_shared_xattrs); + vi->xattr_shared_xattrs = NULL; + ret = PTR_ERR(it.page); + goto out_unlock; + } + + it.kaddr = kmap_atomic(it.page); + atomic_map = true; + it.ofs = 0; + } + vi->xattr_shared_xattrs[i] = + le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs)); + it.ofs += sizeof(__le32); + } + xattr_iter_end(&it, atomic_map); + + set_bit(EROFS_V_EA_INITED_BIT, &vi->flags); + +out_unlock: + clear_and_wake_up_bit(EROFS_V_BL_XATTR_BIT, &vi->flags); + return ret; +} + +/* + * the general idea for these return values is + * if 0 is returned, go on processing the current xattr; + * 1 (> 0) is returned, skip this round to process the next xattr; + * -err (< 0) is returned, an error (maybe ENOXATTR) occurred + * and need to be handled + */ +struct xattr_iter_handlers { + int (*entry)(struct xattr_iter *_it, struct erofs_xattr_entry *entry); + int (*name)(struct xattr_iter *_it, unsigned int processed, char *buf, + unsigned int len); + int (*alloc_buffer)(struct xattr_iter *_it, unsigned int value_sz); + void (*value)(struct xattr_iter *_it, unsigned int processed, char *buf, + unsigned int len); +}; + +static inline int xattr_iter_fixup(struct xattr_iter *it) +{ + if (it->ofs < EROFS_BLKSIZ) + return 0; + + xattr_iter_end(it, true); + + it->blkaddr += erofs_blknr(it->ofs); + + it->page = erofs_get_meta_page(it->sb, it->blkaddr, false); + if (IS_ERR(it->page)) { + int err = PTR_ERR(it->page); + + it->page = NULL; + return err; + } + + it->kaddr = kmap_atomic(it->page); + it->ofs = erofs_blkoff(it->ofs); + return 0; +} + +static int inline_xattr_iter_begin(struct xattr_iter *it, + struct inode *inode) +{ + struct erofs_vnode *const vi = EROFS_V(inode); + struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb); + unsigned int xattr_header_sz, inline_xattr_ofs; + + xattr_header_sz = inlinexattr_header_size(inode); + if (unlikely(xattr_header_sz >= vi->xattr_isize)) { + BUG_ON(xattr_header_sz > vi->xattr_isize); + return -ENOATTR; + } + + inline_xattr_ofs = vi->inode_isize + xattr_header_sz; + + it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs); + it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs); + + it->page = erofs_get_inline_page(inode, it->blkaddr); + if (IS_ERR(it->page)) + return PTR_ERR(it->page); + + it->kaddr = kmap_atomic(it->page); + return vi->xattr_isize - xattr_header_sz; +} + +/* + * Regardless of success or failure, `xattr_foreach' will end up with + * `ofs' pointing to the next xattr item rather than an arbitrary position. + */ +static int xattr_foreach(struct xattr_iter *it, + const struct xattr_iter_handlers *op, + unsigned int *tlimit) +{ + struct erofs_xattr_entry entry; + unsigned int value_sz, processed, slice; + int err; + + /* 0. fixup blkaddr, ofs, ipage */ + err = xattr_iter_fixup(it); + if (err) + return err; + + /* + * 1. read xattr entry to the memory, + * since we do EROFS_XATTR_ALIGN + * therefore entry should be in the page + */ + entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs); + if (tlimit) { + unsigned int entry_sz = EROFS_XATTR_ENTRY_SIZE(&entry); + + BUG_ON(*tlimit < entry_sz); + *tlimit -= entry_sz; + } + + it->ofs += sizeof(struct erofs_xattr_entry); + value_sz = le16_to_cpu(entry.e_value_size); + + /* handle entry */ + err = op->entry(it, &entry); + if (err) { + it->ofs += entry.e_name_len + value_sz; + goto out; + } + + /* 2. handle xattr name (ofs will finally be at the end of name) */ + processed = 0; + + while (processed < entry.e_name_len) { + if (it->ofs >= EROFS_BLKSIZ) { + BUG_ON(it->ofs > EROFS_BLKSIZ); + + err = xattr_iter_fixup(it); + if (err) + goto out; + it->ofs = 0; + } + + slice = min_t(unsigned int, PAGE_SIZE - it->ofs, + entry.e_name_len - processed); + + /* handle name */ + err = op->name(it, processed, it->kaddr + it->ofs, slice); + if (err) { + it->ofs += entry.e_name_len - processed + value_sz; + goto out; + } + + it->ofs += slice; + processed += slice; + } + + /* 3. handle xattr value */ + processed = 0; + + if (op->alloc_buffer) { + err = op->alloc_buffer(it, value_sz); + if (err) { + it->ofs += value_sz; + goto out; + } + } + + while (processed < value_sz) { + if (it->ofs >= EROFS_BLKSIZ) { + BUG_ON(it->ofs > EROFS_BLKSIZ); + + err = xattr_iter_fixup(it); + if (err) + goto out; + it->ofs = 0; + } + + slice = min_t(unsigned int, PAGE_SIZE - it->ofs, + value_sz - processed); + op->value(it, processed, it->kaddr + it->ofs, slice); + it->ofs += slice; + processed += slice; + } + +out: + /* xattrs should be 4-byte aligned (on-disk constraint) */ + it->ofs = EROFS_XATTR_ALIGN(it->ofs); + return err < 0 ? err : 0; +} + +struct getxattr_iter { + struct xattr_iter it; + + char *buffer; + int buffer_size, index; + struct qstr name; +}; + +static int xattr_entrymatch(struct xattr_iter *_it, + struct erofs_xattr_entry *entry) +{ + struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + + return (it->index != entry->e_name_index || + it->name.len != entry->e_name_len) ? -ENOATTR : 0; +} + +static int xattr_namematch(struct xattr_iter *_it, + unsigned int processed, char *buf, unsigned int len) +{ + struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + + return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0; +} + +static int xattr_checkbuffer(struct xattr_iter *_it, + unsigned int value_sz) +{ + struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + int err = it->buffer_size < value_sz ? -ERANGE : 0; + + it->buffer_size = value_sz; + return !it->buffer ? 1 : err; +} + +static void xattr_copyvalue(struct xattr_iter *_it, + unsigned int processed, + char *buf, unsigned int len) +{ + struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + + memcpy(it->buffer + processed, buf, len); +} + +static const struct xattr_iter_handlers find_xattr_handlers = { + .entry = xattr_entrymatch, + .name = xattr_namematch, + .alloc_buffer = xattr_checkbuffer, + .value = xattr_copyvalue +}; + +static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) +{ + int ret; + unsigned int remaining; + + ret = inline_xattr_iter_begin(&it->it, inode); + if (ret < 0) + return ret; + + remaining = ret; + while (remaining) { + ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining); + if (ret != -ENOATTR) + break; + } + xattr_iter_end_final(&it->it); + + return ret ? ret : it->buffer_size; +} + +static int shared_getxattr(struct inode *inode, struct getxattr_iter *it) +{ + struct erofs_vnode *const vi = EROFS_V(inode); + struct super_block *const sb = inode->i_sb; + struct erofs_sb_info *const sbi = EROFS_SB(sb); + unsigned int i; + int ret = -ENOATTR; + + for (i = 0; i < vi->xattr_shared_count; ++i) { + erofs_blk_t blkaddr = + xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]); + + it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]); + + if (!i || blkaddr != it->it.blkaddr) { + if (i) + xattr_iter_end(&it->it, true); + + it->it.page = erofs_get_meta_page(sb, blkaddr, false); + if (IS_ERR(it->it.page)) + return PTR_ERR(it->it.page); + + it->it.kaddr = kmap_atomic(it->it.page); + it->it.blkaddr = blkaddr; + } + + ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL); + if (ret != -ENOATTR) + break; + } + if (vi->xattr_shared_count) + xattr_iter_end_final(&it->it); + + return ret ? ret : it->buffer_size; +} + +static bool erofs_xattr_user_list(struct dentry *dentry) +{ + return test_opt(EROFS_SB(dentry->d_sb), XATTR_USER); +} + +static bool erofs_xattr_trusted_list(struct dentry *dentry) +{ + return capable(CAP_SYS_ADMIN); +} + +int erofs_getxattr(struct inode *inode, int index, + const char *name, + void *buffer, size_t buffer_size) +{ + int ret; + struct getxattr_iter it; + + if (unlikely(!name)) + return -EINVAL; + + ret = init_inode_xattrs(inode); + if (ret) + return ret; + + it.index = index; + + it.name.len = strlen(name); + if (it.name.len > EROFS_NAME_LEN) + return -ERANGE; + it.name.name = name; + + it.buffer = buffer; + it.buffer_size = buffer_size; + + it.it.sb = inode->i_sb; + ret = inline_getxattr(inode, &it); + if (ret == -ENOATTR) + ret = shared_getxattr(inode, &it); + return ret; +} + +static int erofs_xattr_generic_get(const struct xattr_handler *handler, + struct dentry *unused, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + struct erofs_sb_info *const sbi = EROFS_I_SB(inode); + + switch (handler->flags) { + case EROFS_XATTR_INDEX_USER: + if (!test_opt(sbi, XATTR_USER)) + return -EOPNOTSUPP; + break; + case EROFS_XATTR_INDEX_TRUSTED: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + break; + case EROFS_XATTR_INDEX_SECURITY: + break; + default: + return -EINVAL; + } + + return erofs_getxattr(inode, handler->flags, name, buffer, size); +} + +const struct xattr_handler erofs_xattr_user_handler = { + .prefix = XATTR_USER_PREFIX, + .flags = EROFS_XATTR_INDEX_USER, + .list = erofs_xattr_user_list, + .get = erofs_xattr_generic_get, +}; + +const struct xattr_handler erofs_xattr_trusted_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .flags = EROFS_XATTR_INDEX_TRUSTED, + .list = erofs_xattr_trusted_list, + .get = erofs_xattr_generic_get, +}; + +#ifdef CONFIG_EROFS_FS_SECURITY +const struct xattr_handler __maybe_unused erofs_xattr_security_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .flags = EROFS_XATTR_INDEX_SECURITY, + .get = erofs_xattr_generic_get, +}; +#endif + +const struct xattr_handler *erofs_xattr_handlers[] = { + &erofs_xattr_user_handler, +#ifdef CONFIG_EROFS_FS_POSIX_ACL + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, +#endif + &erofs_xattr_trusted_handler, +#ifdef CONFIG_EROFS_FS_SECURITY + &erofs_xattr_security_handler, +#endif + NULL, +}; + +struct listxattr_iter { + struct xattr_iter it; + + struct dentry *dentry; + char *buffer; + int buffer_size, buffer_ofs; +}; + +static int xattr_entrylist(struct xattr_iter *_it, + struct erofs_xattr_entry *entry) +{ + struct listxattr_iter *it = + container_of(_it, struct listxattr_iter, it); + unsigned int prefix_len; + const char *prefix; + + const struct xattr_handler *h = + erofs_xattr_handler(entry->e_name_index); + + if (!h || (h->list && !h->list(it->dentry))) + return 1; + + prefix = xattr_prefix(h); + prefix_len = strlen(prefix); + + if (!it->buffer) { + it->buffer_ofs += prefix_len + entry->e_name_len + 1; + return 1; + } + + if (it->buffer_ofs + prefix_len + + entry->e_name_len + 1 > it->buffer_size) + return -ERANGE; + + memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); + it->buffer_ofs += prefix_len; + return 0; +} + +static int xattr_namelist(struct xattr_iter *_it, + unsigned int processed, char *buf, unsigned int len) +{ + struct listxattr_iter *it = + container_of(_it, struct listxattr_iter, it); + + memcpy(it->buffer + it->buffer_ofs, buf, len); + it->buffer_ofs += len; + return 0; +} + +static int xattr_skipvalue(struct xattr_iter *_it, + unsigned int value_sz) +{ + struct listxattr_iter *it = + container_of(_it, struct listxattr_iter, it); + + it->buffer[it->buffer_ofs++] = '\0'; + return 1; +} + +static const struct xattr_iter_handlers list_xattr_handlers = { + .entry = xattr_entrylist, + .name = xattr_namelist, + .alloc_buffer = xattr_skipvalue, + .value = NULL +}; + +static int inline_listxattr(struct listxattr_iter *it) +{ + int ret; + unsigned int remaining; + + ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry)); + if (ret < 0) + return ret; + + remaining = ret; + while (remaining) { + ret = xattr_foreach(&it->it, &list_xattr_handlers, &remaining); + if (ret) + break; + } + xattr_iter_end_final(&it->it); + return ret ? ret : it->buffer_ofs; +} + +static int shared_listxattr(struct listxattr_iter *it) +{ + struct inode *const inode = d_inode(it->dentry); + struct erofs_vnode *const vi = EROFS_V(inode); + struct super_block *const sb = inode->i_sb; + struct erofs_sb_info *const sbi = EROFS_SB(sb); + unsigned int i; + int ret = 0; + + for (i = 0; i < vi->xattr_shared_count; ++i) { + erofs_blk_t blkaddr = + xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]); + + it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]); + if (!i || blkaddr != it->it.blkaddr) { + if (i) + xattr_iter_end(&it->it, true); + + it->it.page = erofs_get_meta_page(sb, blkaddr, false); + if (IS_ERR(it->it.page)) + return PTR_ERR(it->it.page); + + it->it.kaddr = kmap_atomic(it->it.page); + it->it.blkaddr = blkaddr; + } + + ret = xattr_foreach(&it->it, &list_xattr_handlers, NULL); + if (ret) + break; + } + if (vi->xattr_shared_count) + xattr_iter_end_final(&it->it); + + return ret ? ret : it->buffer_ofs; +} + +ssize_t erofs_listxattr(struct dentry *dentry, + char *buffer, size_t buffer_size) +{ + int ret; + struct listxattr_iter it; + + ret = init_inode_xattrs(d_inode(dentry)); + if (ret) + return ret; + + it.dentry = dentry; + it.buffer = buffer; + it.buffer_size = buffer_size; + it.buffer_ofs = 0; + + it.it.sb = dentry->d_sb; + + ret = inline_listxattr(&it); + if (ret < 0 && ret != -ENOATTR) + return ret; + return shared_listxattr(&it); +} + +#ifdef CONFIG_EROFS_FS_POSIX_ACL +struct posix_acl *erofs_get_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + int prefix, rc; + char *value = NULL; + + switch (type) { + case ACL_TYPE_ACCESS: + prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS; + break; + case ACL_TYPE_DEFAULT: + prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT; + break; + default: + return ERR_PTR(-EINVAL); + } + + rc = erofs_getxattr(inode, prefix, "", NULL, 0); + if (rc > 0) { + value = kmalloc(rc, GFP_KERNEL); + if (!value) + return ERR_PTR(-ENOMEM); + rc = erofs_getxattr(inode, prefix, "", value, rc); + } + + if (rc == -ENOATTR) + acl = NULL; + else if (rc < 0) + acl = ERR_PTR(rc); + else + acl = posix_acl_from_xattr(&init_user_ns, value, rc); + kfree(value); + return acl; +} +#endif + diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h new file mode 100644 index 000000000000..079d6e1821a0 --- /dev/null +++ b/fs/erofs/xattr.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/fs/erofs/xattr.h + * + * Copyright (C) 2017-2018 HUAWEI, Inc. + * http://www.huawei.com/ + * Created by Gao Xiang + */ +#ifndef __EROFS_XATTR_H +#define __EROFS_XATTR_H + +#include "internal.h" +#include +#include + +/* Attribute not found */ +#define ENOATTR ENODATA + +static inline unsigned int inlinexattr_header_size(struct inode *inode) +{ + return sizeof(struct erofs_xattr_ibody_header) + + sizeof(u32) * EROFS_V(inode)->xattr_shared_count; +} + +static inline erofs_blk_t xattrblock_addr(struct erofs_sb_info *sbi, + unsigned int xattr_id) +{ +#ifdef CONFIG_EROFS_FS_XATTR + return sbi->xattr_blkaddr + + xattr_id * sizeof(__u32) / EROFS_BLKSIZ; +#else + return 0; +#endif +} + +static inline unsigned int xattrblock_offset(struct erofs_sb_info *sbi, + unsigned int xattr_id) +{ + return (xattr_id * sizeof(__u32)) % EROFS_BLKSIZ; +} + +#ifdef CONFIG_EROFS_FS_XATTR +extern const struct xattr_handler erofs_xattr_user_handler; +extern const struct xattr_handler erofs_xattr_trusted_handler; +#ifdef CONFIG_EROFS_FS_SECURITY +extern const struct xattr_handler erofs_xattr_security_handler; +#endif + +static inline const struct xattr_handler *erofs_xattr_handler(unsigned int idx) +{ +static const struct xattr_handler *xattr_handler_map[] = { + [EROFS_XATTR_INDEX_USER] = &erofs_xattr_user_handler, +#ifdef CONFIG_EROFS_FS_POSIX_ACL + [EROFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, + [EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = + &posix_acl_default_xattr_handler, +#endif + [EROFS_XATTR_INDEX_TRUSTED] = &erofs_xattr_trusted_handler, +#ifdef CONFIG_EROFS_FS_SECURITY + [EROFS_XATTR_INDEX_SECURITY] = &erofs_xattr_security_handler, +#endif +}; + return idx && idx < ARRAY_SIZE(xattr_handler_map) ? + xattr_handler_map[idx] : NULL; +} + +extern const struct xattr_handler *erofs_xattr_handlers[]; + +int erofs_getxattr(struct inode *, int, const char *, void *, size_t); +ssize_t erofs_listxattr(struct dentry *, char *, size_t); +#else +static inline int erofs_getxattr(struct inode *inode, int index, + const char *name, void *buffer, + size_t buffer_size) +{ + return -ENOTSUPP; +} + +static inline ssize_t erofs_listxattr(struct dentry *dentry, + char *buffer, size_t buffer_size) +{ + return -ENOTSUPP; +} +#endif /* !CONFIG_EROFS_FS_XATTR */ + +#ifdef CONFIG_EROFS_FS_POSIX_ACL +struct posix_acl *erofs_get_acl(struct inode *inode, int type); +#else +#define erofs_get_acl (NULL) +#endif + +#endif + -- 2.17.1