147e4937aSGao Xiang // SPDX-License-Identifier: GPL-2.0-only 247e4937aSGao Xiang /* 347e4937aSGao Xiang * Copyright (C) 2017-2018 HUAWEI, Inc. 4592e7cd0SAlexander A. Klimov * https://www.huawei.com/ 5bb88e8daSGao Xiang * Copyright (C) 2021-2022, Alibaba Cloud 647e4937aSGao Xiang */ 747e4937aSGao Xiang #include <linux/security.h> 847e4937aSGao Xiang #include "xattr.h" 947e4937aSGao Xiang 108e823961SJingbo Xu struct erofs_xattr_iter { 1147e4937aSGao Xiang struct super_block *sb; 12bb88e8daSGao Xiang struct erofs_buf buf; 13eba67eb6SJingbo Xu erofs_off_t pos; 1447e4937aSGao Xiang void *kaddr; 158e823961SJingbo Xu 168e823961SJingbo Xu char *buffer; 178e823961SJingbo Xu int buffer_size, buffer_ofs; 188e823961SJingbo Xu 198e823961SJingbo Xu /* getxattr */ 208e823961SJingbo Xu int index, infix_len; 218e823961SJingbo Xu struct qstr name; 228e823961SJingbo Xu 238e823961SJingbo Xu /* listxattr */ 248e823961SJingbo Xu struct dentry *dentry; 2547e4937aSGao Xiang }; 2647e4937aSGao Xiang 276020ffe7SJingbo Xu static int erofs_init_inode_xattrs(struct inode *inode) 2847e4937aSGao Xiang { 29a5876e24SGao Xiang struct erofs_inode *const vi = EROFS_I(inode); 308e823961SJingbo Xu struct erofs_xattr_iter it; 3147e4937aSGao Xiang unsigned int i; 3247e4937aSGao Xiang struct erofs_xattr_ibody_header *ih; 33b780d3fcSGao Xiang struct super_block *sb = inode->i_sb; 3447e4937aSGao Xiang int ret = 0; 3547e4937aSGao Xiang 3647e4937aSGao Xiang /* the most case is that xattrs of this inode are initialized. */ 37ce063129SGao Xiang if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) { 38ce063129SGao Xiang /* 39ce063129SGao Xiang * paired with smp_mb() at the end of the function to ensure 40ce063129SGao Xiang * fields will only be observed after the bit is set. 41ce063129SGao Xiang */ 42ce063129SGao Xiang smp_mb(); 4347e4937aSGao Xiang return 0; 44ce063129SGao Xiang } 4547e4937aSGao Xiang 46a5876e24SGao Xiang if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE)) 4747e4937aSGao Xiang return -ERESTARTSYS; 4847e4937aSGao Xiang 4947e4937aSGao Xiang /* someone has initialized xattrs for us? */ 50a5876e24SGao Xiang if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) 5147e4937aSGao Xiang goto out_unlock; 5247e4937aSGao Xiang 5347e4937aSGao Xiang /* 5447e4937aSGao Xiang * bypass all xattr operations if ->xattr_isize is not greater than 5547e4937aSGao Xiang * sizeof(struct erofs_xattr_ibody_header), in detail: 5647e4937aSGao Xiang * 1) it is not enough to contain erofs_xattr_ibody_header then 5747e4937aSGao Xiang * ->xattr_isize should be 0 (it means no xattr); 5847e4937aSGao Xiang * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk 5947e4937aSGao Xiang * undefined right now (maybe use later with some new sb feature). 6047e4937aSGao Xiang */ 6147e4937aSGao Xiang if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) { 62b780d3fcSGao Xiang erofs_err(sb, 634f761fa2SGao Xiang "xattr_isize %d of nid %llu is not supported yet", 6447e4937aSGao Xiang vi->xattr_isize, vi->nid); 6547e4937aSGao Xiang ret = -EOPNOTSUPP; 6647e4937aSGao Xiang goto out_unlock; 6747e4937aSGao Xiang } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) { 688d8a09b0SGao Xiang if (vi->xattr_isize) { 69b780d3fcSGao Xiang erofs_err(sb, "bogus xattr ibody @ nid %llu", vi->nid); 7047e4937aSGao Xiang DBG_BUGON(1); 7147e4937aSGao Xiang ret = -EFSCORRUPTED; 7247e4937aSGao Xiang goto out_unlock; /* xattr ondisk layout error */ 7347e4937aSGao Xiang } 7447e4937aSGao Xiang ret = -ENOATTR; 7547e4937aSGao Xiang goto out_unlock; 7647e4937aSGao Xiang } 7747e4937aSGao Xiang 78bb88e8daSGao Xiang it.buf = __EROFS_BUF_INITIALIZER; 799c39ec0cSJingbo Xu erofs_init_metabuf(&it.buf, sb); 80eba67eb6SJingbo Xu it.pos = erofs_iloc(inode) + vi->inode_isize; 8147e4937aSGao Xiang 82bb88e8daSGao Xiang /* read in shared xattr array (non-atomic, see kmalloc below) */ 83eba67eb6SJingbo Xu it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), EROFS_KMAP); 84bb88e8daSGao Xiang if (IS_ERR(it.kaddr)) { 85bb88e8daSGao Xiang ret = PTR_ERR(it.kaddr); 8647e4937aSGao Xiang goto out_unlock; 8747e4937aSGao Xiang } 8847e4937aSGao Xiang 89eba67eb6SJingbo Xu ih = it.kaddr + erofs_blkoff(sb, it.pos); 9047e4937aSGao Xiang vi->xattr_shared_count = ih->h_shared_count; 9147e4937aSGao Xiang vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, 9247e4937aSGao Xiang sizeof(uint), GFP_KERNEL); 9347e4937aSGao Xiang if (!vi->xattr_shared_xattrs) { 94bb88e8daSGao Xiang erofs_put_metabuf(&it.buf); 9547e4937aSGao Xiang ret = -ENOMEM; 9647e4937aSGao Xiang goto out_unlock; 9747e4937aSGao Xiang } 9847e4937aSGao Xiang 9947e4937aSGao Xiang /* let's skip ibody header */ 100eba67eb6SJingbo Xu it.pos += sizeof(struct erofs_xattr_ibody_header); 10147e4937aSGao Xiang 10247e4937aSGao Xiang for (i = 0; i < vi->xattr_shared_count; ++i) { 103eba67eb6SJingbo Xu it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), 104eba67eb6SJingbo Xu EROFS_KMAP); 105bb88e8daSGao Xiang if (IS_ERR(it.kaddr)) { 10647e4937aSGao Xiang kfree(vi->xattr_shared_xattrs); 10747e4937aSGao Xiang vi->xattr_shared_xattrs = NULL; 108bb88e8daSGao Xiang ret = PTR_ERR(it.kaddr); 10947e4937aSGao Xiang goto out_unlock; 11047e4937aSGao Xiang } 111eba67eb6SJingbo Xu vi->xattr_shared_xattrs[i] = le32_to_cpu(*(__le32 *) 112eba67eb6SJingbo Xu (it.kaddr + erofs_blkoff(sb, it.pos))); 113eba67eb6SJingbo Xu it.pos += sizeof(__le32); 11447e4937aSGao Xiang } 115bb88e8daSGao Xiang erofs_put_metabuf(&it.buf); 11647e4937aSGao Xiang 117ce063129SGao Xiang /* paired with smp_mb() at the beginning of the function. */ 118ce063129SGao Xiang smp_mb(); 119a5876e24SGao Xiang set_bit(EROFS_I_EA_INITED_BIT, &vi->flags); 12047e4937aSGao Xiang 12147e4937aSGao Xiang out_unlock: 122a5876e24SGao Xiang clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags); 12347e4937aSGao Xiang return ret; 12447e4937aSGao Xiang } 12547e4937aSGao Xiang 12647e4937aSGao Xiang /* 12747e4937aSGao Xiang * the general idea for these return values is 12847e4937aSGao Xiang * if 0 is returned, go on processing the current xattr; 12947e4937aSGao Xiang * 1 (> 0) is returned, skip this round to process the next xattr; 13047e4937aSGao Xiang * -err (< 0) is returned, an error (maybe ENOXATTR) occurred 13147e4937aSGao Xiang * and need to be handled 13247e4937aSGao Xiang */ 13347e4937aSGao Xiang struct xattr_iter_handlers { 1348e823961SJingbo Xu int (*entry)(struct erofs_xattr_iter *it, struct erofs_xattr_entry *entry); 1358e823961SJingbo Xu int (*name)(struct erofs_xattr_iter *it, unsigned int processed, char *buf, 13647e4937aSGao Xiang unsigned int len); 1378e823961SJingbo Xu int (*alloc_buffer)(struct erofs_xattr_iter *it, unsigned int value_sz); 1388e823961SJingbo Xu void (*value)(struct erofs_xattr_iter *it, unsigned int processed, char *buf, 13947e4937aSGao Xiang unsigned int len); 14047e4937aSGao Xiang }; 14147e4937aSGao Xiang 14247e4937aSGao Xiang /* 14347e4937aSGao Xiang * Regardless of success or failure, `xattr_foreach' will end up with 144eba67eb6SJingbo Xu * `pos' pointing to the next xattr item rather than an arbitrary position. 14547e4937aSGao Xiang */ 1468e823961SJingbo Xu static int xattr_foreach(struct erofs_xattr_iter *it, 14747e4937aSGao Xiang const struct xattr_iter_handlers *op, 14847e4937aSGao Xiang unsigned int *tlimit) 14947e4937aSGao Xiang { 15047e4937aSGao Xiang struct erofs_xattr_entry entry; 151eba67eb6SJingbo Xu struct super_block *sb = it->sb; 15247e4937aSGao Xiang unsigned int value_sz, processed, slice; 15347e4937aSGao Xiang int err; 15447e4937aSGao Xiang 155eba67eb6SJingbo Xu /* 0. fixup blkaddr, pos */ 156eba67eb6SJingbo Xu it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), EROFS_KMAP); 157eba67eb6SJingbo Xu if (IS_ERR(it->kaddr)) 158eba67eb6SJingbo Xu return PTR_ERR(it->kaddr); 15947e4937aSGao Xiang 16047e4937aSGao Xiang /* 16147e4937aSGao Xiang * 1. read xattr entry to the memory, 16247e4937aSGao Xiang * since we do EROFS_XATTR_ALIGN 16347e4937aSGao Xiang * therefore entry should be in the page 16447e4937aSGao Xiang */ 165eba67eb6SJingbo Xu entry = *(struct erofs_xattr_entry *) 166eba67eb6SJingbo Xu (it->kaddr + erofs_blkoff(sb, it->pos)); 16747e4937aSGao Xiang if (tlimit) { 168b6796abdSGao Xiang unsigned int entry_sz = erofs_xattr_entry_size(&entry); 16947e4937aSGao Xiang 17047e4937aSGao Xiang /* xattr on-disk corruption: xattr entry beyond xattr_isize */ 1718d8a09b0SGao Xiang if (*tlimit < entry_sz) { 17247e4937aSGao Xiang DBG_BUGON(1); 17347e4937aSGao Xiang return -EFSCORRUPTED; 17447e4937aSGao Xiang } 17547e4937aSGao Xiang *tlimit -= entry_sz; 17647e4937aSGao Xiang } 17747e4937aSGao Xiang 178eba67eb6SJingbo Xu it->pos += sizeof(struct erofs_xattr_entry); 17947e4937aSGao Xiang value_sz = le16_to_cpu(entry.e_value_size); 18047e4937aSGao Xiang 18147e4937aSGao Xiang /* handle entry */ 18247e4937aSGao Xiang err = op->entry(it, &entry); 18347e4937aSGao Xiang if (err) { 184eba67eb6SJingbo Xu it->pos += entry.e_name_len + value_sz; 18547e4937aSGao Xiang goto out; 18647e4937aSGao Xiang } 18747e4937aSGao Xiang 188eba67eb6SJingbo Xu /* 2. handle xattr name (pos will finally be at the end of name) */ 18947e4937aSGao Xiang processed = 0; 19047e4937aSGao Xiang 19147e4937aSGao Xiang while (processed < entry.e_name_len) { 192eba67eb6SJingbo Xu it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), 193eba67eb6SJingbo Xu EROFS_KMAP); 194eba67eb6SJingbo Xu if (IS_ERR(it->kaddr)) { 195eba67eb6SJingbo Xu err = PTR_ERR(it->kaddr); 19647e4937aSGao Xiang goto out; 19747e4937aSGao Xiang } 19847e4937aSGao Xiang 199eba67eb6SJingbo Xu slice = min_t(unsigned int, 200eba67eb6SJingbo Xu sb->s_blocksize - erofs_blkoff(sb, it->pos), 20147e4937aSGao Xiang entry.e_name_len - processed); 20247e4937aSGao Xiang 20347e4937aSGao Xiang /* handle name */ 204eba67eb6SJingbo Xu err = op->name(it, processed, 205eba67eb6SJingbo Xu it->kaddr + erofs_blkoff(sb, it->pos), slice); 20647e4937aSGao Xiang if (err) { 207eba67eb6SJingbo Xu it->pos += entry.e_name_len - processed + value_sz; 20847e4937aSGao Xiang goto out; 20947e4937aSGao Xiang } 21047e4937aSGao Xiang 211eba67eb6SJingbo Xu it->pos += slice; 21247e4937aSGao Xiang processed += slice; 21347e4937aSGao Xiang } 21447e4937aSGao Xiang 21547e4937aSGao Xiang /* 3. handle xattr value */ 21647e4937aSGao Xiang processed = 0; 21747e4937aSGao Xiang 21847e4937aSGao Xiang if (op->alloc_buffer) { 21947e4937aSGao Xiang err = op->alloc_buffer(it, value_sz); 22047e4937aSGao Xiang if (err) { 221eba67eb6SJingbo Xu it->pos += value_sz; 22247e4937aSGao Xiang goto out; 22347e4937aSGao Xiang } 22447e4937aSGao Xiang } 22547e4937aSGao Xiang 22647e4937aSGao Xiang while (processed < value_sz) { 227eba67eb6SJingbo Xu it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), 228eba67eb6SJingbo Xu EROFS_KMAP); 229eba67eb6SJingbo Xu if (IS_ERR(it->kaddr)) { 230eba67eb6SJingbo Xu err = PTR_ERR(it->kaddr); 23147e4937aSGao Xiang goto out; 23247e4937aSGao Xiang } 23347e4937aSGao Xiang 234eba67eb6SJingbo Xu slice = min_t(unsigned int, 235eba67eb6SJingbo Xu sb->s_blocksize - erofs_blkoff(sb, it->pos), 23647e4937aSGao Xiang value_sz - processed); 237eba67eb6SJingbo Xu op->value(it, processed, it->kaddr + erofs_blkoff(sb, it->pos), 238eba67eb6SJingbo Xu slice); 239eba67eb6SJingbo Xu it->pos += slice; 24047e4937aSGao Xiang processed += slice; 24147e4937aSGao Xiang } 24247e4937aSGao Xiang 24347e4937aSGao Xiang out: 24447e4937aSGao Xiang /* xattrs should be 4-byte aligned (on-disk constraint) */ 245eba67eb6SJingbo Xu it->pos = EROFS_XATTR_ALIGN(it->pos); 24647e4937aSGao Xiang return err < 0 ? err : 0; 24747e4937aSGao Xiang } 24847e4937aSGao Xiang 2498e823961SJingbo Xu static int erofs_xattr_long_entrymatch(struct erofs_xattr_iter *it, 25082bc1ef4SJingbo Xu struct erofs_xattr_entry *entry) 25182bc1ef4SJingbo Xu { 2528e823961SJingbo Xu struct erofs_sb_info *sbi = EROFS_SB(it->sb); 25382bc1ef4SJingbo Xu struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + 25482bc1ef4SJingbo Xu (entry->e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); 25582bc1ef4SJingbo Xu 25682bc1ef4SJingbo Xu if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) 25782bc1ef4SJingbo Xu return -ENOATTR; 25882bc1ef4SJingbo Xu 25982bc1ef4SJingbo Xu if (it->index != pf->prefix->base_index || 26082bc1ef4SJingbo Xu it->name.len != entry->e_name_len + pf->infix_len) 26182bc1ef4SJingbo Xu return -ENOATTR; 26282bc1ef4SJingbo Xu 26382bc1ef4SJingbo Xu if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len)) 26482bc1ef4SJingbo Xu return -ENOATTR; 26582bc1ef4SJingbo Xu 26682bc1ef4SJingbo Xu it->infix_len = pf->infix_len; 26782bc1ef4SJingbo Xu return 0; 26882bc1ef4SJingbo Xu } 26982bc1ef4SJingbo Xu 2708e823961SJingbo Xu static int xattr_entrymatch(struct erofs_xattr_iter *it, 27147e4937aSGao Xiang struct erofs_xattr_entry *entry) 27247e4937aSGao Xiang { 27382bc1ef4SJingbo Xu /* should also match the infix for long name prefixes */ 27482bc1ef4SJingbo Xu if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) 27582bc1ef4SJingbo Xu return erofs_xattr_long_entrymatch(it, entry); 27682bc1ef4SJingbo Xu 27782bc1ef4SJingbo Xu if (it->index != entry->e_name_index || 27882bc1ef4SJingbo Xu it->name.len != entry->e_name_len) 27982bc1ef4SJingbo Xu return -ENOATTR; 28082bc1ef4SJingbo Xu it->infix_len = 0; 28182bc1ef4SJingbo Xu return 0; 28247e4937aSGao Xiang } 28347e4937aSGao Xiang 2848e823961SJingbo Xu static int xattr_namematch(struct erofs_xattr_iter *it, 28547e4937aSGao Xiang unsigned int processed, char *buf, unsigned int len) 28647e4937aSGao Xiang { 28782bc1ef4SJingbo Xu if (memcmp(buf, it->name.name + it->infix_len + processed, len)) 28882bc1ef4SJingbo Xu return -ENOATTR; 28982bc1ef4SJingbo Xu return 0; 29047e4937aSGao Xiang } 29147e4937aSGao Xiang 2928e823961SJingbo Xu static int xattr_checkbuffer(struct erofs_xattr_iter *it, 29347e4937aSGao Xiang unsigned int value_sz) 29447e4937aSGao Xiang { 29547e4937aSGao Xiang int err = it->buffer_size < value_sz ? -ERANGE : 0; 29647e4937aSGao Xiang 2975a8ffb19SJingbo Xu it->buffer_ofs = value_sz; 29847e4937aSGao Xiang return !it->buffer ? 1 : err; 29947e4937aSGao Xiang } 30047e4937aSGao Xiang 3018e823961SJingbo Xu static void xattr_copyvalue(struct erofs_xattr_iter *it, 30247e4937aSGao Xiang unsigned int processed, 30347e4937aSGao Xiang char *buf, unsigned int len) 30447e4937aSGao Xiang { 30547e4937aSGao Xiang memcpy(it->buffer + processed, buf, len); 30647e4937aSGao Xiang } 30747e4937aSGao Xiang 30847e4937aSGao Xiang static const struct xattr_iter_handlers find_xattr_handlers = { 30947e4937aSGao Xiang .entry = xattr_entrymatch, 31047e4937aSGao Xiang .name = xattr_namematch, 31147e4937aSGao Xiang .alloc_buffer = xattr_checkbuffer, 31247e4937aSGao Xiang .value = xattr_copyvalue 31347e4937aSGao Xiang }; 31447e4937aSGao Xiang 31547e4937aSGao Xiang static bool erofs_xattr_user_list(struct dentry *dentry) 31647e4937aSGao Xiang { 317e6242465SGao Xiang return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER); 31847e4937aSGao Xiang } 31947e4937aSGao Xiang 32047e4937aSGao Xiang static bool erofs_xattr_trusted_list(struct dentry *dentry) 32147e4937aSGao Xiang { 32247e4937aSGao Xiang return capable(CAP_SYS_ADMIN); 32347e4937aSGao Xiang } 32447e4937aSGao Xiang 32547e4937aSGao Xiang static int erofs_xattr_generic_get(const struct xattr_handler *handler, 32647e4937aSGao Xiang struct dentry *unused, struct inode *inode, 32747e4937aSGao Xiang const char *name, void *buffer, size_t size) 32847e4937aSGao Xiang { 329b05f30bcSJingbo Xu if (handler->flags == EROFS_XATTR_INDEX_USER && 330b05f30bcSJingbo Xu !test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER)) 33147e4937aSGao Xiang return -EOPNOTSUPP; 33247e4937aSGao Xiang 33347e4937aSGao Xiang return erofs_getxattr(inode, handler->flags, name, buffer, size); 33447e4937aSGao Xiang } 33547e4937aSGao Xiang 33647e4937aSGao Xiang const struct xattr_handler erofs_xattr_user_handler = { 33747e4937aSGao Xiang .prefix = XATTR_USER_PREFIX, 33847e4937aSGao Xiang .flags = EROFS_XATTR_INDEX_USER, 33947e4937aSGao Xiang .list = erofs_xattr_user_list, 34047e4937aSGao Xiang .get = erofs_xattr_generic_get, 34147e4937aSGao Xiang }; 34247e4937aSGao Xiang 34347e4937aSGao Xiang const struct xattr_handler erofs_xattr_trusted_handler = { 34447e4937aSGao Xiang .prefix = XATTR_TRUSTED_PREFIX, 34547e4937aSGao Xiang .flags = EROFS_XATTR_INDEX_TRUSTED, 34647e4937aSGao Xiang .list = erofs_xattr_trusted_list, 34747e4937aSGao Xiang .get = erofs_xattr_generic_get, 34847e4937aSGao Xiang }; 34947e4937aSGao Xiang 35047e4937aSGao Xiang #ifdef CONFIG_EROFS_FS_SECURITY 35147e4937aSGao Xiang const struct xattr_handler __maybe_unused erofs_xattr_security_handler = { 35247e4937aSGao Xiang .prefix = XATTR_SECURITY_PREFIX, 35347e4937aSGao Xiang .flags = EROFS_XATTR_INDEX_SECURITY, 35447e4937aSGao Xiang .get = erofs_xattr_generic_get, 35547e4937aSGao Xiang }; 35647e4937aSGao Xiang #endif 35747e4937aSGao Xiang 35847e4937aSGao Xiang const struct xattr_handler *erofs_xattr_handlers[] = { 35947e4937aSGao Xiang &erofs_xattr_user_handler, 36047e4937aSGao Xiang &erofs_xattr_trusted_handler, 36147e4937aSGao Xiang #ifdef CONFIG_EROFS_FS_SECURITY 36247e4937aSGao Xiang &erofs_xattr_security_handler, 36347e4937aSGao Xiang #endif 36447e4937aSGao Xiang NULL, 36547e4937aSGao Xiang }; 36647e4937aSGao Xiang 3678e823961SJingbo Xu static int xattr_entrylist(struct erofs_xattr_iter *it, 36847e4937aSGao Xiang struct erofs_xattr_entry *entry) 36947e4937aSGao Xiang { 37082bc1ef4SJingbo Xu unsigned int base_index = entry->e_name_index; 37182bc1ef4SJingbo Xu unsigned int prefix_len, infix_len = 0; 37282bc1ef4SJingbo Xu const char *prefix, *infix = NULL; 37347e4937aSGao Xiang 37482bc1ef4SJingbo Xu if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) { 3758e823961SJingbo Xu struct erofs_sb_info *sbi = EROFS_SB(it->sb); 37682bc1ef4SJingbo Xu struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + 37782bc1ef4SJingbo Xu (entry->e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); 37847e4937aSGao Xiang 37982bc1ef4SJingbo Xu if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) 38082bc1ef4SJingbo Xu return 1; 38182bc1ef4SJingbo Xu infix = pf->prefix->infix; 38282bc1ef4SJingbo Xu infix_len = pf->infix_len; 38382bc1ef4SJingbo Xu base_index = pf->prefix->base_index; 38482bc1ef4SJingbo Xu } 38582bc1ef4SJingbo Xu 38661d325dcSLinus Torvalds prefix = erofs_xattr_prefix(base_index, it->dentry); 387a5488f29SChristian Brauner if (!prefix) 38847e4937aSGao Xiang return 1; 38947e4937aSGao Xiang prefix_len = strlen(prefix); 39047e4937aSGao Xiang 39147e4937aSGao Xiang if (!it->buffer) { 39282bc1ef4SJingbo Xu it->buffer_ofs += prefix_len + infix_len + 39382bc1ef4SJingbo Xu entry->e_name_len + 1; 39447e4937aSGao Xiang return 1; 39547e4937aSGao Xiang } 39647e4937aSGao Xiang 39782bc1ef4SJingbo Xu if (it->buffer_ofs + prefix_len + infix_len + 39847e4937aSGao Xiang + entry->e_name_len + 1 > it->buffer_size) 39947e4937aSGao Xiang return -ERANGE; 40047e4937aSGao Xiang 40147e4937aSGao Xiang memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); 40282bc1ef4SJingbo Xu memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len); 40382bc1ef4SJingbo Xu it->buffer_ofs += prefix_len + infix_len; 40447e4937aSGao Xiang return 0; 40547e4937aSGao Xiang } 40647e4937aSGao Xiang 4078e823961SJingbo Xu static int xattr_namelist(struct erofs_xattr_iter *it, 40847e4937aSGao Xiang unsigned int processed, char *buf, unsigned int len) 40947e4937aSGao Xiang { 41047e4937aSGao Xiang memcpy(it->buffer + it->buffer_ofs, buf, len); 41147e4937aSGao Xiang it->buffer_ofs += len; 41247e4937aSGao Xiang return 0; 41347e4937aSGao Xiang } 41447e4937aSGao Xiang 4158e823961SJingbo Xu static int xattr_skipvalue(struct erofs_xattr_iter *it, 41647e4937aSGao Xiang unsigned int value_sz) 41747e4937aSGao Xiang { 41847e4937aSGao Xiang it->buffer[it->buffer_ofs++] = '\0'; 41947e4937aSGao Xiang return 1; 42047e4937aSGao Xiang } 42147e4937aSGao Xiang 42247e4937aSGao Xiang static const struct xattr_iter_handlers list_xattr_handlers = { 42347e4937aSGao Xiang .entry = xattr_entrylist, 42447e4937aSGao Xiang .name = xattr_namelist, 42547e4937aSGao Xiang .alloc_buffer = xattr_skipvalue, 42647e4937aSGao Xiang .value = NULL 42747e4937aSGao Xiang }; 42847e4937aSGao Xiang 429*4b077b50SJingbo Xu static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it, 430*4b077b50SJingbo Xu struct inode *inode, bool getxattr) 43147e4937aSGao Xiang { 432*4b077b50SJingbo Xu struct erofs_inode *const vi = EROFS_I(inode); 433*4b077b50SJingbo Xu const struct xattr_iter_handlers *op; 434*4b077b50SJingbo Xu unsigned int xattr_header_sz, remaining; 43547e4937aSGao Xiang int ret; 43647e4937aSGao Xiang 437*4b077b50SJingbo Xu xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + 438*4b077b50SJingbo Xu sizeof(u32) * vi->xattr_shared_count; 439*4b077b50SJingbo Xu if (xattr_header_sz >= vi->xattr_isize) { 440*4b077b50SJingbo Xu DBG_BUGON(xattr_header_sz > vi->xattr_isize); 441*4b077b50SJingbo Xu return -ENOATTR; 442*4b077b50SJingbo Xu } 44347e4937aSGao Xiang 444*4b077b50SJingbo Xu it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; 445*4b077b50SJingbo Xu it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos), 446*4b077b50SJingbo Xu EROFS_KMAP); 447*4b077b50SJingbo Xu if (IS_ERR(it->kaddr)) 448*4b077b50SJingbo Xu return PTR_ERR(it->kaddr); 449*4b077b50SJingbo Xu 450*4b077b50SJingbo Xu remaining = vi->xattr_isize - xattr_header_sz; 451*4b077b50SJingbo Xu op = getxattr ? &find_xattr_handlers : &list_xattr_handlers; 452*4b077b50SJingbo Xu 45347e4937aSGao Xiang while (remaining) { 454*4b077b50SJingbo Xu ret = xattr_foreach(it, op, &remaining); 455*4b077b50SJingbo Xu if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) 45647e4937aSGao Xiang break; 45747e4937aSGao Xiang } 458*4b077b50SJingbo Xu return ret; 45947e4937aSGao Xiang } 46047e4937aSGao Xiang 461*4b077b50SJingbo Xu static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it, 462*4b077b50SJingbo Xu struct inode *inode, bool getxattr) 46347e4937aSGao Xiang { 464a5876e24SGao Xiang struct erofs_inode *const vi = EROFS_I(inode); 4658e823961SJingbo Xu struct super_block *const sb = it->sb; 466eba67eb6SJingbo Xu struct erofs_sb_info *sbi = EROFS_SB(sb); 467eba67eb6SJingbo Xu unsigned int i; 468*4b077b50SJingbo Xu const struct xattr_iter_handlers *op; 469*4b077b50SJingbo Xu int ret = -ENOATTR; 470*4b077b50SJingbo Xu 471*4b077b50SJingbo Xu op = getxattr ? &find_xattr_handlers : &list_xattr_handlers; 47247e4937aSGao Xiang 47347e4937aSGao Xiang for (i = 0; i < vi->xattr_shared_count; ++i) { 4748e823961SJingbo Xu it->pos = erofs_pos(sb, sbi->xattr_blkaddr) + 475eba67eb6SJingbo Xu vi->xattr_shared_xattrs[i] * sizeof(__le32); 4768e823961SJingbo Xu it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), 4778e823961SJingbo Xu EROFS_KMAP); 4788e823961SJingbo Xu if (IS_ERR(it->kaddr)) 4798e823961SJingbo Xu return PTR_ERR(it->kaddr); 48047e4937aSGao Xiang 481*4b077b50SJingbo Xu ret = xattr_foreach(it, op, NULL); 482*4b077b50SJingbo Xu if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) 48347e4937aSGao Xiang break; 48447e4937aSGao Xiang } 485*4b077b50SJingbo Xu return ret; 48647e4937aSGao Xiang } 48747e4937aSGao Xiang 488*4b077b50SJingbo Xu int erofs_getxattr(struct inode *inode, int index, const char *name, 489*4b077b50SJingbo Xu void *buffer, size_t buffer_size) 49047e4937aSGao Xiang { 49147e4937aSGao Xiang int ret; 4928e823961SJingbo Xu struct erofs_xattr_iter it; 49347e4937aSGao Xiang 494*4b077b50SJingbo Xu if (!name) 495*4b077b50SJingbo Xu return -EINVAL; 496*4b077b50SJingbo Xu 497*4b077b50SJingbo Xu ret = erofs_init_inode_xattrs(inode); 498*4b077b50SJingbo Xu if (ret) 499*4b077b50SJingbo Xu return ret; 500*4b077b50SJingbo Xu 501*4b077b50SJingbo Xu it.index = index; 502*4b077b50SJingbo Xu it.name = (struct qstr)QSTR_INIT(name, strlen(name)); 503*4b077b50SJingbo Xu if (it.name.len > EROFS_NAME_LEN) 504*4b077b50SJingbo Xu return -ERANGE; 505*4b077b50SJingbo Xu 506*4b077b50SJingbo Xu it.sb = inode->i_sb; 507*4b077b50SJingbo Xu it.buf = __EROFS_BUF_INITIALIZER; 508*4b077b50SJingbo Xu erofs_init_metabuf(&it.buf, it.sb); 509*4b077b50SJingbo Xu it.buffer = buffer; 510*4b077b50SJingbo Xu it.buffer_size = buffer_size; 511*4b077b50SJingbo Xu it.buffer_ofs = 0; 512*4b077b50SJingbo Xu 513*4b077b50SJingbo Xu ret = erofs_xattr_iter_inline(&it, inode, true); 514*4b077b50SJingbo Xu if (ret == -ENOATTR) 515*4b077b50SJingbo Xu ret = erofs_xattr_iter_shared(&it, inode, true); 516*4b077b50SJingbo Xu erofs_put_metabuf(&it.buf); 517*4b077b50SJingbo Xu return ret ? ret : it.buffer_ofs; 518*4b077b50SJingbo Xu } 519*4b077b50SJingbo Xu 520*4b077b50SJingbo Xu ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 521*4b077b50SJingbo Xu { 522*4b077b50SJingbo Xu int ret; 523*4b077b50SJingbo Xu struct erofs_xattr_iter it; 524*4b077b50SJingbo Xu struct inode *inode = d_inode(dentry); 525*4b077b50SJingbo Xu 526*4b077b50SJingbo Xu ret = erofs_init_inode_xattrs(inode); 527926d1650SGao Xiang if (ret == -ENOATTR) 528926d1650SGao Xiang return 0; 52947e4937aSGao Xiang if (ret) 53047e4937aSGao Xiang return ret; 53147e4937aSGao Xiang 5328e823961SJingbo Xu it.sb = dentry->d_sb; 5338e823961SJingbo Xu it.buf = __EROFS_BUF_INITIALIZER; 5348e823961SJingbo Xu erofs_init_metabuf(&it.buf, it.sb); 53547e4937aSGao Xiang it.dentry = dentry; 53647e4937aSGao Xiang it.buffer = buffer; 53747e4937aSGao Xiang it.buffer_size = buffer_size; 53847e4937aSGao Xiang it.buffer_ofs = 0; 53947e4937aSGao Xiang 540*4b077b50SJingbo Xu ret = erofs_xattr_iter_inline(&it, inode, false); 541*4b077b50SJingbo Xu if (!ret || ret == -ENOATTR) 542*4b077b50SJingbo Xu ret = erofs_xattr_iter_shared(&it, inode, false); 543*4b077b50SJingbo Xu if (ret == -ENOATTR) 544*4b077b50SJingbo Xu ret = 0; 5458e823961SJingbo Xu erofs_put_metabuf(&it.buf); 546*4b077b50SJingbo Xu return ret ? ret : it.buffer_ofs; 54747e4937aSGao Xiang } 54847e4937aSGao Xiang 5499e382914SJingbo Xu void erofs_xattr_prefixes_cleanup(struct super_block *sb) 5509e382914SJingbo Xu { 5519e382914SJingbo Xu struct erofs_sb_info *sbi = EROFS_SB(sb); 5529e382914SJingbo Xu int i; 5539e382914SJingbo Xu 5549e382914SJingbo Xu if (sbi->xattr_prefixes) { 5559e382914SJingbo Xu for (i = 0; i < sbi->xattr_prefix_count; i++) 5569e382914SJingbo Xu kfree(sbi->xattr_prefixes[i].prefix); 5579e382914SJingbo Xu kfree(sbi->xattr_prefixes); 5589e382914SJingbo Xu sbi->xattr_prefixes = NULL; 5599e382914SJingbo Xu } 5609e382914SJingbo Xu } 5619e382914SJingbo Xu 5629e382914SJingbo Xu int erofs_xattr_prefixes_init(struct super_block *sb) 5639e382914SJingbo Xu { 5649e382914SJingbo Xu struct erofs_sb_info *sbi = EROFS_SB(sb); 5659e382914SJingbo Xu struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 5669e382914SJingbo Xu erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2; 5679e382914SJingbo Xu struct erofs_xattr_prefix_item *pfs; 5689e382914SJingbo Xu int ret = 0, i, len; 5699e382914SJingbo Xu 5709e382914SJingbo Xu if (!sbi->xattr_prefix_count) 5719e382914SJingbo Xu return 0; 5729e382914SJingbo Xu 5739e382914SJingbo Xu pfs = kzalloc(sbi->xattr_prefix_count * sizeof(*pfs), GFP_KERNEL); 5749e382914SJingbo Xu if (!pfs) 5759e382914SJingbo Xu return -ENOMEM; 5769e382914SJingbo Xu 5770a17567bSJingbo Xu if (sbi->packed_inode) 5789e382914SJingbo Xu buf.inode = sbi->packed_inode; 5799e382914SJingbo Xu else 5809e382914SJingbo Xu erofs_init_metabuf(&buf, sb); 5819e382914SJingbo Xu 5829e382914SJingbo Xu for (i = 0; i < sbi->xattr_prefix_count; i++) { 5839e382914SJingbo Xu void *ptr = erofs_read_metadata(sb, &buf, &pos, &len); 5849e382914SJingbo Xu 5859e382914SJingbo Xu if (IS_ERR(ptr)) { 5869e382914SJingbo Xu ret = PTR_ERR(ptr); 5879e382914SJingbo Xu break; 5889e382914SJingbo Xu } else if (len < sizeof(*pfs->prefix) || 5899e382914SJingbo Xu len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) { 5909e382914SJingbo Xu kfree(ptr); 5919e382914SJingbo Xu ret = -EFSCORRUPTED; 5929e382914SJingbo Xu break; 5939e382914SJingbo Xu } 5949e382914SJingbo Xu pfs[i].prefix = ptr; 5959e382914SJingbo Xu pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix); 5969e382914SJingbo Xu } 5979e382914SJingbo Xu 5989e382914SJingbo Xu erofs_put_metabuf(&buf); 5999e382914SJingbo Xu sbi->xattr_prefixes = pfs; 6009e382914SJingbo Xu if (ret) 6019e382914SJingbo Xu erofs_xattr_prefixes_cleanup(sb); 6029e382914SJingbo Xu return ret; 6039e382914SJingbo Xu } 6049e382914SJingbo Xu 60547e4937aSGao Xiang #ifdef CONFIG_EROFS_FS_POSIX_ACL 6060cad6246SMiklos Szeredi struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu) 60747e4937aSGao Xiang { 60847e4937aSGao Xiang struct posix_acl *acl; 60947e4937aSGao Xiang int prefix, rc; 61047e4937aSGao Xiang char *value = NULL; 61147e4937aSGao Xiang 6120cad6246SMiklos Szeredi if (rcu) 6130cad6246SMiklos Szeredi return ERR_PTR(-ECHILD); 6140cad6246SMiklos Szeredi 61547e4937aSGao Xiang switch (type) { 61647e4937aSGao Xiang case ACL_TYPE_ACCESS: 61747e4937aSGao Xiang prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS; 61847e4937aSGao Xiang break; 61947e4937aSGao Xiang case ACL_TYPE_DEFAULT: 62047e4937aSGao Xiang prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT; 62147e4937aSGao Xiang break; 62247e4937aSGao Xiang default: 62347e4937aSGao Xiang return ERR_PTR(-EINVAL); 62447e4937aSGao Xiang } 62547e4937aSGao Xiang 62647e4937aSGao Xiang rc = erofs_getxattr(inode, prefix, "", NULL, 0); 62747e4937aSGao Xiang if (rc > 0) { 62847e4937aSGao Xiang value = kmalloc(rc, GFP_KERNEL); 62947e4937aSGao Xiang if (!value) 63047e4937aSGao Xiang return ERR_PTR(-ENOMEM); 63147e4937aSGao Xiang rc = erofs_getxattr(inode, prefix, "", value, rc); 63247e4937aSGao Xiang } 63347e4937aSGao Xiang 63447e4937aSGao Xiang if (rc == -ENOATTR) 63547e4937aSGao Xiang acl = NULL; 63647e4937aSGao Xiang else if (rc < 0) 63747e4937aSGao Xiang acl = ERR_PTR(rc); 63847e4937aSGao Xiang else 63947e4937aSGao Xiang acl = posix_acl_from_xattr(&init_user_ns, value, rc); 64047e4937aSGao Xiang kfree(value); 64147e4937aSGao Xiang return acl; 64247e4937aSGao Xiang } 64347e4937aSGao Xiang #endif 644