This implements xattr and acl functionalities. Inline and shared xattrs are introduced for flexibility. Specifically, if the same xattr occurs for many times in a large number of inodes or the value of a xattr is so large that it isn't suitable to be inlined, a shared xattr kept in the xattr meta will be used instead. Signed-off-by: Miao Xie <miaoxie@xxxxxxxxxx> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx> --- drivers/staging/erofs/Kconfig | 37 +++ drivers/staging/erofs/Makefile | 1 + drivers/staging/erofs/inode.c | 33 ++- drivers/staging/erofs/internal.h | 22 ++ drivers/staging/erofs/namei.c | 4 + drivers/staging/erofs/super.c | 67 +++++ drivers/staging/erofs/xattr.c | 579 +++++++++++++++++++++++++++++++++++++++ drivers/staging/erofs/xattr.h | 93 +++++++ 8 files changed, 835 insertions(+), 1 deletion(-) create mode 100644 drivers/staging/erofs/xattr.c create mode 100644 drivers/staging/erofs/xattr.h diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig index 077430f..1a5ec1b 100644 --- a/drivers/staging/erofs/Kconfig +++ b/drivers/staging/erofs/Kconfig @@ -26,6 +26,43 @@ config EROFS_FS_DEBUG For daily use, 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 + <http://acl.bestbits.at/> 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 <http://acl.bestbits.at/>. + + 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 + 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. + config EROFS_FS_USE_VM_MAP_RAM bool "EROFS VM_MAP_RAM Support" depends on EROFS_FS diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile index 31e909e..977b7e0 100644 --- a/drivers/staging/erofs/Makefile +++ b/drivers/staging/erofs/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o # staging requirement: to be self-contained in its own directory ccflags-y += -I$(src)/include erofs-objs := super.o inode.o data.o namei.o dir.o +erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c index 74e65be..15ed919 100644 --- a/drivers/staging/erofs/inode.c +++ b/drivers/staging/erofs/inode.c @@ -10,7 +10,7 @@ * License. See the file COPYING in the main directory of the Linux * distribution for more details. */ -#include "internal.h" +#include "xattr.h" /* no locking */ static int read_inode(struct inode *inode, void *data) @@ -152,15 +152,26 @@ static int fill_inode(struct inode *inode, int isdir) if (!err) { /* setup the new inode */ if (S_ISREG(inode->i_mode)) { +#ifdef CONFIG_EROFS_FS_XATTR + if (vi->xattr_isize) + inode->i_op = &erofs_generic_xattr_iops; +#endif inode->i_fop = &generic_ro_fops; } else if (S_ISDIR(inode->i_mode)) { inode->i_op = +#ifdef CONFIG_EROFS_FS_XATTR + vi->xattr_isize ? &erofs_dir_xattr_iops : +#endif &erofs_dir_iops; inode->i_fop = &erofs_dir_fops; } else if (S_ISLNK(inode->i_mode)) { /* by default, page_get_link is used for symlink */ inode->i_op = +#ifdef CONFIG_EROFS_FS_XATTR + &erofs_symlink_xattr_iops, +#else &page_symlink_inode_operations; +#endif inode_nohighmem(inode); } else { err = -EIO; @@ -208,3 +219,23 @@ struct inode *erofs_iget(struct super_block *sb, return inode; } +#ifdef CONFIG_EROFS_FS_XATTR +const struct inode_operations erofs_generic_xattr_iops = { + .listxattr = erofs_listxattr, +}; +#endif + +#ifdef CONFIG_EROFS_FS_XATTR +const struct inode_operations erofs_symlink_xattr_iops = { + .get_link = page_get_link, + .listxattr = erofs_listxattr, +}; +#endif + +#ifdef CONFIG_EROFS_FS_XATTR +const struct inode_operations erofs_fast_symlink_xattr_iops = { + .get_link = simple_get_link, + .listxattr = erofs_listxattr, +}; +#endif + diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h index d0992d2..8a8caf0 100644 --- a/drivers/staging/erofs/internal.h +++ b/drivers/staging/erofs/internal.h @@ -50,6 +50,9 @@ 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; @@ -72,6 +75,10 @@ struct erofs_sb_info { #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) #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 clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option) #define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option) #define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option) @@ -237,17 +244,32 @@ int erofs_namei(struct inode *dir, struct qstr *name, erofs_nid_t *nid, unsigned *d_type); /* xattr.c */ +#ifdef CONFIG_EROFS_FS_XATTR extern const struct xattr_handler *erofs_xattr_handlers[]; +#endif /* symlink */ +#ifdef CONFIG_EROFS_FS_XATTR +extern const struct inode_operations erofs_symlink_xattr_iops; +extern const struct inode_operations erofs_fast_symlink_xattr_iops; +#endif + static inline void set_inode_fast_symlink(struct inode *inode) { +#ifdef CONFIG_EROFS_FS_XATTR + inode->i_op = &erofs_fast_symlink_xattr_iops; +#else inode->i_op = &simple_symlink_inode_operations; +#endif } static inline bool is_inode_fast_symlink(struct inode *inode) { +#ifdef CONFIG_EROFS_FS_XATTR + return inode->i_op == &erofs_fast_symlink_xattr_iops; +#else return inode->i_op == &simple_symlink_inode_operations; +#endif } static inline void *erofs_vmap(struct page **pages, unsigned int count) diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c index 39db643..989876b 100644 --- a/drivers/staging/erofs/namei.c +++ b/drivers/staging/erofs/namei.c @@ -11,6 +11,7 @@ * distribution for more details. */ #include "internal.h" +#include "xattr.h" /* based on the value of qn->len is accurate */ static inline int dirnamecmp(struct qstr *qn, @@ -239,5 +240,8 @@ static struct dentry *erofs_lookup(struct inode *dir, const struct inode_operations erofs_dir_xattr_iops = { .lookup = erofs_lookup, +#ifdef CONFIG_EROFS_FS_XATTR + .listxattr = erofs_listxattr, +#endif }; diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c index 98ae03d..4a8a266 100644 --- a/drivers/staging/erofs/super.c +++ b/drivers/staging/erofs/super.c @@ -14,6 +14,7 @@ #include <linux/buffer_head.h> #include <linux/statfs.h> #include <linux/parser.h> +#include <linux/seq_file.h> #include "internal.h" static struct kmem_cache *erofs_inode_cachep __read_mostly; @@ -107,6 +108,9 @@ 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); @@ -127,13 +131,28 @@ static int superblock_read(struct super_block *sb) 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_err }; static match_table_t erofs_tokens = { + {Opt_user_xattr, "user_xattr"}, + {Opt_nouser_xattr, "nouser_xattr"}, + {Opt_acl, "acl"}, + {Opt_noacl, "noacl"}, {Opt_err, NULL} }; @@ -155,6 +174,36 @@ 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 default: errln("Unrecognized mount option \"%s\" " "or missing value", p); @@ -197,6 +246,10 @@ static int erofs_read_super(struct super_block *sb, 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); @@ -386,6 +439,20 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) 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 return 0; } diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c new file mode 100644 index 0000000..b74b314 --- /dev/null +++ b/drivers/staging/erofs/xattr.c @@ -0,0 +1,579 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/drivers/staging/erofs/xattr.c + * + * Copyright (C) 2017-2018 HUAWEI, Inc. + * http://www.huawei.com/ + * Created by Gao Xiang <gaoxiang25@xxxxxxxxxx> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ +#include <linux/security.h> +#include "xattr.h" + +struct xattr_iter { + struct super_block *sb; + struct page *page; + void *kaddr; + + erofs_blk_t blkaddr; + unsigned ofs; +}; + +static inline void xattr_iter_end(struct xattr_iter *it, bool atomic) +{ + /* only init_inode_xattrs use non-atomic once */ + if (unlikely(!atomic)) + kunmap(it->page); + else + kunmap_atomic(it->kaddr); + unlock_page(it->page); + put_page(it->page); +} + +static void init_inode_xattrs(struct inode *inode) +{ + struct xattr_iter it; + unsigned i; + struct erofs_xattr_ibody_header *ih; + struct erofs_sb_info *sbi; + struct erofs_vnode *vi; + bool atomic_map; + + if (likely(inode_has_inited_xattr(inode))) + return; + + vi = EROFS_V(inode); + BUG_ON(!vi->xattr_isize); + + sbi = EROFS_I_SB(inode); + 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); + BUG_ON(IS_ERR(it.page)); + + /* 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 = (unsigned *)kmalloc_array( + vi->xattr_shared_count, sizeof(unsigned), + GFP_KERNEL | __GFP_NOFAIL); + + /* 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(inode->i_sb, + ++it.blkaddr, S_ISDIR(inode->i_mode)); + BUG_ON(IS_ERR(it.page)); + + 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); + + inode_set_inited_xattr(inode); +} + +struct xattr_iter_handlers { + int (*entry)(struct xattr_iter *, struct erofs_xattr_entry *); + int (*name)(struct xattr_iter *, unsigned, char *, unsigned); + int (*alloc_buffer)(struct xattr_iter *, unsigned); + void (*value)(struct xattr_iter *, unsigned, char *, unsigned); +}; + +static void xattr_iter_fixup(struct xattr_iter *it) +{ + if (unlikely(it->ofs >= EROFS_BLKSIZ)) { + xattr_iter_end(it, true); + + it->blkaddr += erofs_blknr(it->ofs); + it->page = erofs_get_meta_page(it->sb, it->blkaddr, false); + BUG_ON(IS_ERR(it->page)); + + it->kaddr = kmap_atomic(it->page); + it->ofs = erofs_blkoff(it->ofs); + } +} + +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 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); + BUG_ON(IS_ERR(it->page)); + it->kaddr = kmap_atomic(it->page); + + return vi->xattr_isize - xattr_header_sz; +} + +static int xattr_foreach(struct xattr_iter *it, + struct xattr_iter_handlers *op, unsigned *tlimit) +{ + struct erofs_xattr_entry entry; + unsigned value_sz, processed, slice; + int err; + + /* 0. fixup blkaddr, ofs, ipage */ + xattr_iter_fixup(it); + + /* + * 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 != NULL) { + unsigned 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); + + xattr_iter_fixup(it); + it->ofs = 0; + } + + slice = min_t(unsigned, 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 != NULL) { + 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); + xattr_iter_fixup(it); + it->ofs = 0; + } + + slice = min_t(unsigned, PAGE_SIZE - it->ofs, + value_sz - processed); + op->value(it, processed, it->kaddr + it->ofs, slice); + it->ofs += slice; + processed += slice; + } + +out: + /* we assume that ofs is aligned with 4 bytes */ + it->ofs = EROFS_XATTR_ALIGN(it->ofs); + return err; +} + +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 processed, char *buf, unsigned 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 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 == NULL ? 1 : err; +} + +static void xattr_copyvalue(struct xattr_iter *_it, + unsigned processed, char *buf, unsigned len) +{ + struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + + memcpy(it->buffer + processed, buf, len); +} + +static 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 remaining; + + ret = inline_xattr_iter_begin(&it->it, inode); + if (ret < 0) + return ret; + + remaining = ret; + while (remaining) { + if ((ret = xattr_foreach(&it->it, + &find_xattr_handlers, &remaining)) >= 0) + break; + } + xattr_iter_end(&it->it, true); + + return ret < 0 ? ret : it->buffer_size; +} + +static int shared_getxattr(struct inode *inode, struct getxattr_iter *it) +{ + struct erofs_vnode *const vi = EROFS_V(inode); + struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb); + unsigned 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(inode->i_sb, + blkaddr, false); + BUG_ON(IS_ERR(it->it.page)); + it->it.kaddr = kmap_atomic(it->it.page); + it->it.blkaddr = blkaddr; + } + + if ((ret = xattr_foreach(&it->it, + &find_xattr_handlers, NULL)) >= 0) + break; + } + if (vi->xattr_shared_count) + xattr_iter_end(&it->it, true); + + return ret < 0 ? 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 == NULL)) + return -EINVAL; + + init_inode_xattrs(inode); + + 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_vnode *const vi = EROFS_V(inode); + 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; + } + + if (!vi->xattr_isize) + return -ENOATTR; + + 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 + +#ifdef CONFIG_EROFS_FS_XATTR +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, +}; +#endif + +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 prefix_len; + const char *prefix; + + const struct xattr_handler *h = + erofs_xattr_handler(entry->e_name_index); + + if (h == NULL || (h->list != NULL && !h->list(it->dentry))) + return 1; + + /* Note that at least one of 'prefix' and 'name' should be non-NULL */ + prefix = h->prefix != NULL ? h->prefix : h->name; + prefix_len = strlen(prefix); + + if (it->buffer == NULL) { + 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 processed, char *buf, unsigned 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 value_sz) +{ + struct listxattr_iter *it = + container_of(_it, struct listxattr_iter, it); + + it->buffer[it->buffer_ofs++] = '\0'; + return 1; +} + +static 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 remaining; + + ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry)); + if (ret < 0) + return ret; + + remaining = ret; + while (remaining) { + if ((ret = xattr_foreach(&it->it, + &list_xattr_handlers, &remaining)) < 0) + break; + } + xattr_iter_end(&it->it, true); + return ret < 0 ? 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 erofs_sb_info *const sbi = EROFS_I_SB(inode); + unsigned 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(inode->i_sb, + blkaddr, false); + BUG_ON(IS_ERR(it->it.page)); + it->it.kaddr = kmap_atomic(it->it.page); + it->it.blkaddr = blkaddr; + } + + if ((ret = xattr_foreach(&it->it, + &list_xattr_handlers, NULL)) < 0) + break; + } + if (vi->xattr_shared_count) + xattr_iter_end(&it->it, true); + + return ret < 0 ? ret : it->buffer_ofs; +} + +ssize_t erofs_listxattr(struct dentry *dentry, + char *buffer, size_t buffer_size) +{ + int ret; + struct listxattr_iter it; + + init_inode_xattrs(d_inode(dentry)); + + 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); +} + diff --git a/drivers/staging/erofs/xattr.h b/drivers/staging/erofs/xattr.h new file mode 100644 index 0000000..0c73792 --- /dev/null +++ b/drivers/staging/erofs/xattr.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * linux/drivers/staging/erofs/xattr.h + * + * Copyright (C) 2017-2018 HUAWEI, Inc. + * http://www.huawei.com/ + * Created by Gao Xiang <gaoxiang25@xxxxxxxxxx> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ +#ifndef __EROFS_XATTR_H +#define __EROFS_XATTR_H + +#include "internal.h" +#include <linux/posix_acl_xattr.h> +#include <linux/xattr.h> + +/* Attribute not found */ +#define ENOATTR ENODATA + +static inline unsigned 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 xattr_id) +{ +#ifdef CONFIG_EROFS_FS_XATTR + return sbi->xattr_blkaddr + + xattr_id * sizeof(__u32) / EROFS_BLKSIZ; +#else + return 0; +#endif +} + +static inline unsigned +xattrblock_offset(struct erofs_sb_info *sbi, unsigned xattr_id) +{ + return (xattr_id * sizeof(__u32)) % EROFS_BLKSIZ; +} + +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 index) +{ +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 index && index < ARRAY_SIZE(xattr_handler_map) ? + xattr_handler_map[index] : NULL; +} + +#ifdef CONFIG_EROFS_FS_XATTR + +extern const struct inode_operations erofs_generic_xattr_iops; +extern const struct inode_operations erofs_dir_xattr_iops; + +int erofs_getxattr(struct inode *, int, const char *, void *, size_t); +ssize_t erofs_listxattr(struct dentry *, char *, size_t); +#else +static int __maybe_unused erofs_getxattr(struct inode *inode, int index, + const char *name, + void *buffer, size_t buffer_size) +{ + return -ENOTSUPP; +} + +static ssize_t __maybe_unused erofs_listxattr(struct dentry *dentry, + char *buffer, size_t buffer_size) +{ + return -ENOTSUPP; +} +#endif + +#endif + -- 1.9.1
