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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /fs/erofs/xattr.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/erofs/xattr.c')
-rw-r--r-- | fs/erofs/xattr.c | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c new file mode 100644 index 0000000000..09d341675e --- /dev/null +++ b/fs/erofs/xattr.c @@ -0,0 +1,560 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2018 HUAWEI, Inc. + * https://www.huawei.com/ + * Copyright (C) 2021-2022, Alibaba Cloud + */ +#include <linux/security.h> +#include <linux/xxhash.h> +#include "xattr.h" + +struct erofs_xattr_iter { + struct super_block *sb; + struct erofs_buf buf; + erofs_off_t pos; + void *kaddr; + + char *buffer; + int buffer_size, buffer_ofs; + + /* getxattr */ + int index, infix_len; + struct qstr name; + + /* listxattr */ + struct dentry *dentry; +}; + +static int erofs_init_inode_xattrs(struct inode *inode) +{ + struct erofs_inode *const vi = EROFS_I(inode); + struct erofs_xattr_iter it; + unsigned int i; + struct erofs_xattr_ibody_header *ih; + struct super_block *sb = inode->i_sb; + int ret = 0; + + /* the most case is that xattrs of this inode are initialized. */ + if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) { + /* + * paired with smp_mb() at the end of the function to ensure + * fields will only be observed after the bit is set. + */ + smp_mb(); + return 0; + } + + if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE)) + return -ERESTARTSYS; + + /* someone has initialized xattrs for us? */ + if (test_bit(EROFS_I_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)) { + erofs_err(sb, + "xattr_isize %d of nid %llu is not supported yet", + vi->xattr_isize, vi->nid); + ret = -EOPNOTSUPP; + goto out_unlock; + } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) { + if (vi->xattr_isize) { + erofs_err(sb, "bogus xattr ibody @ nid %llu", vi->nid); + DBG_BUGON(1); + ret = -EFSCORRUPTED; + goto out_unlock; /* xattr ondisk layout error */ + } + ret = -ENOATTR; + goto out_unlock; + } + + it.buf = __EROFS_BUF_INITIALIZER; + erofs_init_metabuf(&it.buf, sb); + it.pos = erofs_iloc(inode) + vi->inode_isize; + + /* read in shared xattr array (non-atomic, see kmalloc below) */ + it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), EROFS_KMAP); + if (IS_ERR(it.kaddr)) { + ret = PTR_ERR(it.kaddr); + goto out_unlock; + } + + ih = it.kaddr + erofs_blkoff(sb, it.pos); + vi->xattr_name_filter = le32_to_cpu(ih->h_name_filter); + 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) { + erofs_put_metabuf(&it.buf); + ret = -ENOMEM; + goto out_unlock; + } + + /* let's skip ibody header */ + it.pos += sizeof(struct erofs_xattr_ibody_header); + + for (i = 0; i < vi->xattr_shared_count; ++i) { + it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), + EROFS_KMAP); + if (IS_ERR(it.kaddr)) { + kfree(vi->xattr_shared_xattrs); + vi->xattr_shared_xattrs = NULL; + ret = PTR_ERR(it.kaddr); + goto out_unlock; + } + vi->xattr_shared_xattrs[i] = le32_to_cpu(*(__le32 *) + (it.kaddr + erofs_blkoff(sb, it.pos))); + it.pos += sizeof(__le32); + } + erofs_put_metabuf(&it.buf); + + /* paired with smp_mb() at the beginning of the function. */ + smp_mb(); + set_bit(EROFS_I_EA_INITED_BIT, &vi->flags); + +out_unlock: + clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags); + return ret; +} + +static bool erofs_xattr_user_list(struct dentry *dentry) +{ + return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER); +} + +static bool erofs_xattr_trusted_list(struct dentry *dentry) +{ + return capable(CAP_SYS_ADMIN); +} + +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) +{ + if (handler->flags == EROFS_XATTR_INDEX_USER && + !test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER)) + return -EOPNOTSUPP; + + 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, + &erofs_xattr_trusted_handler, +#ifdef CONFIG_EROFS_FS_SECURITY + &erofs_xattr_security_handler, +#endif + NULL, +}; + +static int erofs_xattr_copy_to_buffer(struct erofs_xattr_iter *it, + unsigned int len) +{ + unsigned int slice, processed; + struct super_block *sb = it->sb; + void *src; + + for (processed = 0; processed < len; processed += slice) { + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); + + src = it->kaddr + erofs_blkoff(sb, it->pos); + slice = min_t(unsigned int, sb->s_blocksize - + erofs_blkoff(sb, it->pos), len - processed); + memcpy(it->buffer + it->buffer_ofs, src, slice); + it->buffer_ofs += slice; + it->pos += slice; + } + return 0; +} + +static int erofs_listxattr_foreach(struct erofs_xattr_iter *it) +{ + struct erofs_xattr_entry entry; + unsigned int base_index, name_total, prefix_len, infix_len = 0; + const char *prefix, *infix = NULL; + int err; + + /* 1. handle xattr entry */ + entry = *(struct erofs_xattr_entry *) + (it->kaddr + erofs_blkoff(it->sb, it->pos)); + it->pos += sizeof(struct erofs_xattr_entry); + + base_index = entry.e_name_index; + if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) { + struct erofs_sb_info *sbi = EROFS_SB(it->sb); + struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + + (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); + + if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) + return 0; + infix = pf->prefix->infix; + infix_len = pf->infix_len; + base_index = pf->prefix->base_index; + } + + prefix = erofs_xattr_prefix(base_index, it->dentry); + if (!prefix) + return 0; + prefix_len = strlen(prefix); + name_total = prefix_len + infix_len + entry.e_name_len + 1; + + if (!it->buffer) { + it->buffer_ofs += name_total; + return 0; + } + + if (it->buffer_ofs + name_total > it->buffer_size) + return -ERANGE; + + memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); + memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len); + it->buffer_ofs += prefix_len + infix_len; + + /* 2. handle xattr name */ + err = erofs_xattr_copy_to_buffer(it, entry.e_name_len); + if (err) + return err; + + it->buffer[it->buffer_ofs++] = '\0'; + return 0; +} + +static int erofs_getxattr_foreach(struct erofs_xattr_iter *it) +{ + struct super_block *sb = it->sb; + struct erofs_xattr_entry entry; + unsigned int slice, processed, value_sz; + + /* 1. handle xattr entry */ + entry = *(struct erofs_xattr_entry *) + (it->kaddr + erofs_blkoff(sb, it->pos)); + it->pos += sizeof(struct erofs_xattr_entry); + value_sz = le16_to_cpu(entry.e_value_size); + + /* should also match the infix for long name prefixes */ + if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) { + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + + (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); + + if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) + return -ENOATTR; + + if (it->index != pf->prefix->base_index || + it->name.len != entry.e_name_len + pf->infix_len) + return -ENOATTR; + + if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len)) + return -ENOATTR; + + it->infix_len = pf->infix_len; + } else { + if (it->index != entry.e_name_index || + it->name.len != entry.e_name_len) + return -ENOATTR; + + it->infix_len = 0; + } + + /* 2. handle xattr name */ + for (processed = 0; processed < entry.e_name_len; processed += slice) { + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); + + slice = min_t(unsigned int, + sb->s_blocksize - erofs_blkoff(sb, it->pos), + entry.e_name_len - processed); + if (memcmp(it->name.name + it->infix_len + processed, + it->kaddr + erofs_blkoff(sb, it->pos), slice)) + return -ENOATTR; + it->pos += slice; + } + + /* 3. handle xattr value */ + if (!it->buffer) { + it->buffer_ofs = value_sz; + return 0; + } + + if (it->buffer_size < value_sz) + return -ERANGE; + + return erofs_xattr_copy_to_buffer(it, value_sz); +} + +static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it, + struct inode *inode, bool getxattr) +{ + struct erofs_inode *const vi = EROFS_I(inode); + unsigned int xattr_header_sz, remaining, entry_sz; + erofs_off_t next_pos; + int ret; + + xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + + sizeof(u32) * vi->xattr_shared_count; + if (xattr_header_sz >= vi->xattr_isize) { + DBG_BUGON(xattr_header_sz > vi->xattr_isize); + return -ENOATTR; + } + + remaining = vi->xattr_isize - xattr_header_sz; + it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; + + while (remaining) { + it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); + + entry_sz = erofs_xattr_entry_size(it->kaddr + + erofs_blkoff(it->sb, it->pos)); + /* xattr on-disk corruption: xattr entry beyond xattr_isize */ + if (remaining < entry_sz) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + remaining -= entry_sz; + next_pos = it->pos + entry_sz; + + if (getxattr) + ret = erofs_getxattr_foreach(it); + else + ret = erofs_listxattr_foreach(it); + if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) + break; + + it->pos = next_pos; + } + return ret; +} + +static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it, + struct inode *inode, bool getxattr) +{ + struct erofs_inode *const vi = EROFS_I(inode); + struct super_block *const sb = it->sb; + struct erofs_sb_info *sbi = EROFS_SB(sb); + unsigned int i; + int ret = -ENOATTR; + + for (i = 0; i < vi->xattr_shared_count; ++i) { + it->pos = erofs_pos(sb, sbi->xattr_blkaddr) + + vi->xattr_shared_xattrs[i] * sizeof(__le32); + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); + + if (getxattr) + ret = erofs_getxattr_foreach(it); + else + ret = erofs_listxattr_foreach(it); + if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) + break; + } + return ret; +} + +int erofs_getxattr(struct inode *inode, int index, const char *name, + void *buffer, size_t buffer_size) +{ + int ret; + unsigned int hashbit; + struct erofs_xattr_iter it; + struct erofs_inode *vi = EROFS_I(inode); + struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); + + if (!name) + return -EINVAL; + + ret = erofs_init_inode_xattrs(inode); + if (ret) + return ret; + + /* reserved flag is non-zero if there's any change of on-disk format */ + if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved) { + hashbit = xxh32(name, strlen(name), + EROFS_XATTR_FILTER_SEED + index); + hashbit &= EROFS_XATTR_FILTER_BITS - 1; + if (vi->xattr_name_filter & (1U << hashbit)) + return -ENOATTR; + } + + it.index = index; + it.name = (struct qstr)QSTR_INIT(name, strlen(name)); + if (it.name.len > EROFS_NAME_LEN) + return -ERANGE; + + it.sb = inode->i_sb; + it.buf = __EROFS_BUF_INITIALIZER; + erofs_init_metabuf(&it.buf, it.sb); + it.buffer = buffer; + it.buffer_size = buffer_size; + it.buffer_ofs = 0; + + ret = erofs_xattr_iter_inline(&it, inode, true); + if (ret == -ENOATTR) + ret = erofs_xattr_iter_shared(&it, inode, true); + erofs_put_metabuf(&it.buf); + return ret ? ret : it.buffer_ofs; +} + +ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) +{ + int ret; + struct erofs_xattr_iter it; + struct inode *inode = d_inode(dentry); + + ret = erofs_init_inode_xattrs(inode); + if (ret == -ENOATTR) + return 0; + if (ret) + return ret; + + it.sb = dentry->d_sb; + it.buf = __EROFS_BUF_INITIALIZER; + erofs_init_metabuf(&it.buf, it.sb); + it.dentry = dentry; + it.buffer = buffer; + it.buffer_size = buffer_size; + it.buffer_ofs = 0; + + ret = erofs_xattr_iter_inline(&it, inode, false); + if (!ret || ret == -ENOATTR) + ret = erofs_xattr_iter_shared(&it, inode, false); + if (ret == -ENOATTR) + ret = 0; + erofs_put_metabuf(&it.buf); + return ret ? ret : it.buffer_ofs; +} + +void erofs_xattr_prefixes_cleanup(struct super_block *sb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + int i; + + if (sbi->xattr_prefixes) { + for (i = 0; i < sbi->xattr_prefix_count; i++) + kfree(sbi->xattr_prefixes[i].prefix); + kfree(sbi->xattr_prefixes); + sbi->xattr_prefixes = NULL; + } +} + +int erofs_xattr_prefixes_init(struct super_block *sb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2; + struct erofs_xattr_prefix_item *pfs; + int ret = 0, i, len; + + if (!sbi->xattr_prefix_count) + return 0; + + pfs = kzalloc(sbi->xattr_prefix_count * sizeof(*pfs), GFP_KERNEL); + if (!pfs) + return -ENOMEM; + + if (sbi->packed_inode) + buf.inode = sbi->packed_inode; + else + erofs_init_metabuf(&buf, sb); + + for (i = 0; i < sbi->xattr_prefix_count; i++) { + void *ptr = erofs_read_metadata(sb, &buf, &pos, &len); + + if (IS_ERR(ptr)) { + ret = PTR_ERR(ptr); + break; + } else if (len < sizeof(*pfs->prefix) || + len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) { + kfree(ptr); + ret = -EFSCORRUPTED; + break; + } + pfs[i].prefix = ptr; + pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix); + } + + erofs_put_metabuf(&buf); + sbi->xattr_prefixes = pfs; + if (ret) + erofs_xattr_prefixes_cleanup(sb); + return ret; +} + +#ifdef CONFIG_EROFS_FS_POSIX_ACL +struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu) +{ + struct posix_acl *acl; + int prefix, rc; + char *value = NULL; + + if (rcu) + return ERR_PTR(-ECHILD); + + 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 |