/* * fs/f2fs/acl.c * * Copyright (c) 2012 Samsung Electronics Co., Ltd. * http://www.samsung.com/ * * Portions of this code from linux/fs/ext2/acl.c * * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/f2fs_fs.h> #include "f2fs.h" #include "xattr.h" #include "acl.h" static inline size_t f2fs_acl_size(int count) { if (count <= 4) { return sizeof(struct f2fs_acl_header) + count * sizeof(struct f2fs_acl_entry_short); } else { return sizeof(struct f2fs_acl_header) + 4 * sizeof(struct f2fs_acl_entry_short) + (count - 4) * sizeof(struct f2fs_acl_entry); } } static inline int f2fs_acl_count(size_t size) { ssize_t s; size -= sizeof(struct f2fs_acl_header); s = size - 4 * sizeof(struct f2fs_acl_entry_short); if (s < 0) { if (size % sizeof(struct f2fs_acl_entry_short)) return -1; return size / sizeof(struct f2fs_acl_entry_short); } else { if (s % sizeof(struct f2fs_acl_entry)) return -1; return s / sizeof(struct f2fs_acl_entry) + 4; } } static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) { int i, count; struct posix_acl *acl; struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); const char *end = value + size; if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) return ERR_PTR(-EINVAL); count = f2fs_acl_count(size); if (count < 0) return ERR_PTR(-EINVAL); if (count == 0) return NULL; acl = posix_acl_alloc(count, GFP_NOFS); if (!acl) return ERR_PTR(-ENOMEM); for (i = 0; i < count; i++) { if ((char *)entry > end) goto fail; acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag); acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); switch (acl->a_entries[i].e_tag) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry_short)); break; case ACL_USER: acl->a_entries[i].e_uid = make_kuid(&init_user_ns, le32_to_cpu(entry->e_id)); entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry)); break; case ACL_GROUP: acl->a_entries[i].e_gid = make_kgid(&init_user_ns, le32_to_cpu(entry->e_id)); entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry)); break; default: goto fail; } } if ((char *)entry != end) goto fail; return acl; fail: posix_acl_release(acl); return ERR_PTR(-EINVAL); } static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi, const struct posix_acl *acl, size_t *size) { struct f2fs_acl_header *f2fs_acl; struct f2fs_acl_entry *entry; int i; f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + acl->a_count * sizeof(struct f2fs_acl_entry), GFP_NOFS); if (!f2fs_acl) return ERR_PTR(-ENOMEM); f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); for (i = 0; i < acl->a_count; i++) { entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); switch (acl->a_entries[i].e_tag) { case ACL_USER: entry->e_id = cpu_to_le32( from_kuid(&init_user_ns, acl->a_entries[i].e_uid)); entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry)); break; case ACL_GROUP: entry->e_id = cpu_to_le32( from_kgid(&init_user_ns, acl->a_entries[i].e_gid)); entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry)); break; case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: entry = (struct f2fs_acl_entry *)((char *)entry + sizeof(struct f2fs_acl_entry_short)); break; default: goto fail; } } *size = f2fs_acl_size(acl->a_count); return (void *)f2fs_acl; fail: kfree(f2fs_acl); return ERR_PTR(-EINVAL); } static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, struct page *dpage) { int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; void *value = NULL; struct posix_acl *acl; int retval; if (type == ACL_TYPE_ACCESS) name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage); if (retval > 0) { value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); if (!value) return ERR_PTR(-ENOMEM); retval = f2fs_getxattr(inode, name_index, "", value, retval, dpage); } if (retval > 0) acl = f2fs_acl_from_disk(value, retval); else if (retval == -ENODATA) acl = NULL; else acl = ERR_PTR(retval); kfree(value); return acl; } struct posix_acl *f2fs_get_acl(struct inode *inode, int type) { return __f2fs_get_acl(inode, type, NULL); } static int __f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl, struct page *ipage) { int name_index; void *value = NULL; size_t size = 0; int error; umode_t mode = inode->i_mode; switch (type) { case ACL_TYPE_ACCESS: name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; if (acl && !ipage) { error = posix_acl_update_mode(inode, &mode, &acl); if (error) return error; set_acl_inode(inode, mode); } break; case ACL_TYPE_DEFAULT: name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; if (!S_ISDIR(inode->i_mode)) return acl ? -EACCES : 0; break; default: return -EINVAL; } if (acl) { value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); if (IS_ERR(value)) { clear_inode_flag(inode, FI_ACL_MODE); return PTR_ERR(value); } } error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); kfree(value); if (!error) set_cached_acl(inode, type, acl); clear_inode_flag(inode, FI_ACL_MODE); return error; } int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type) { if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) return -EIO; return __f2fs_set_acl(inode, type, acl, NULL); } /* * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create * are copied from posix_acl.c */ static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, gfp_t flags) { struct posix_acl *clone = NULL; if (acl) { int size = sizeof(struct posix_acl) + acl->a_count * sizeof(struct posix_acl_entry); clone = kmemdup(acl, size, flags); if (clone) refcount_set(&clone->a_refcount, 1); } return clone; } static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) { struct posix_acl_entry *pa, *pe; struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; umode_t mode = *mode_p; int not_equiv = 0; /* assert(atomic_read(acl->a_refcount) == 1); */ FOREACH_ACL_ENTRY(pa, acl, pe) { switch(pa->e_tag) { case ACL_USER_OBJ: pa->e_perm &= (mode >> 6) | ~S_IRWXO; mode &= (pa->e_perm << 6) | ~S_IRWXU; break; case ACL_USER: case ACL_GROUP: not_equiv = 1; break; case ACL_GROUP_OBJ: group_obj = pa; break; case ACL_OTHER: pa->e_perm &= mode | ~S_IRWXO; mode &= pa->e_perm | ~S_IRWXO; break; case ACL_MASK: mask_obj = pa; not_equiv = 1; break; default: return -EIO; } } if (mask_obj) { mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; } else { if (!group_obj) return -EIO; group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; mode &= (group_obj->e_perm << 3) | ~S_IRWXG; } *mode_p = (*mode_p & ~S_IRWXUGO) | mode; return not_equiv; } static int f2fs_acl_create(struct inode *dir, umode_t *mode, struct posix_acl **default_acl, struct posix_acl **acl, struct page *dpage) { struct posix_acl *p; struct posix_acl *clone; int ret; *acl = NULL; *default_acl = NULL; if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) return 0; p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); if (!p || p == ERR_PTR(-EOPNOTSUPP)) { *mode &= ~current_umask(); return 0; } if (IS_ERR(p)) return PTR_ERR(p); clone = f2fs_acl_clone(p, GFP_NOFS); if (!clone) goto no_mem; ret = f2fs_acl_create_masq(clone, mode); if (ret < 0) goto no_mem_clone; if (ret == 0) posix_acl_release(clone); else *acl = clone; if (!S_ISDIR(*mode)) posix_acl_release(p); else *default_acl = p; return 0; no_mem_clone: posix_acl_release(clone); no_mem: posix_acl_release(p); return -ENOMEM; } int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, struct page *dpage) { struct posix_acl *default_acl = NULL, *acl = NULL; int error = 0; error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); if (error) return error; f2fs_mark_inode_dirty_sync(inode, true); if (default_acl) { error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, ipage); posix_acl_release(default_acl); } if (acl) { if (!error) error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, ipage); posix_acl_release(acl); } return error; }