#include <linux/capability.h> #include <linux/fs.h> #include <linux/posix_acl.h> #include <linux/reiserfs_fs.h> #include <linux/errno.h> #include <linux/pagemap.h> #include <linux/xattr.h> #include <linux/slab.h> #include <linux/posix_acl_xattr.h> #include <linux/reiserfs_xattr.h> #include <linux/reiserfs_acl.h> #include <asm/uaccess.h> static int reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, int type, struct posix_acl *acl); static int posix_acl_set(struct dentry *dentry, const char *name, const void *value, size_t size, int flags, int type) { struct inode *inode = dentry->d_inode; struct posix_acl *acl; int error, error2; struct reiserfs_transaction_handle th; size_t jcreate_blocks; if (!reiserfs_posixacl(inode->i_sb)) return -EOPNOTSUPP; if (!is_owner_or_cap(inode)) return -EPERM; if (value) { acl = posix_acl_from_xattr(value, size); if (IS_ERR(acl)) { return PTR_ERR(acl); } else if (acl) { error = posix_acl_valid(acl); if (error) goto release_and_out; } } else acl = NULL; /* Pessimism: We can't assume that anything from the xattr root up * has been created. */ jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + reiserfs_xattr_nblocks(inode, size) * 2; reiserfs_write_lock(inode->i_sb); error = journal_begin(&th, inode->i_sb, jcreate_blocks); if (error == 0) { error = reiserfs_set_acl(&th, inode, type, acl); error2 = journal_end(&th, inode->i_sb, jcreate_blocks); if (error2) error = error2; } reiserfs_write_unlock(inode->i_sb); release_and_out: posix_acl_release(acl); return error; } static int posix_acl_get(struct dentry *dentry, const char *name, void *buffer, size_t size, int type) { struct posix_acl *acl; int error; if (!reiserfs_posixacl(dentry->d_sb)) return -EOPNOTSUPP; acl = reiserfs_get_acl(dentry->d_inode, type); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl == NULL) return -ENODATA; error = posix_acl_to_xattr(acl, buffer, size); posix_acl_release(acl); return error; } /* * Convert from filesystem to in-memory representation. */ static struct posix_acl *posix_acl_from_disk(const void *value, size_t size) { const char *end = (char *)value + size; int n, count; struct posix_acl *acl; if (!value) return NULL; if (size < sizeof(reiserfs_acl_header)) return ERR_PTR(-EINVAL); if (((reiserfs_acl_header *) value)->a_version != cpu_to_le32(REISERFS_ACL_VERSION)) return ERR_PTR(-EINVAL); value = (char *)value + sizeof(reiserfs_acl_header); count = reiserfs_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 (n = 0; n < count; n++) { reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) goto fail; acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: value = (char *)value + sizeof(reiserfs_acl_entry_short); acl->a_entries[n].e_id = ACL_UNDEFINED_ID; break; case ACL_USER: case ACL_GROUP: value = (char *)value + sizeof(reiserfs_acl_entry); if ((char *)value > end) goto fail; acl->a_entries[n].e_id = le32_to_cpu(entry->e_id); break; default: goto fail; } } if (value != end) goto fail; return acl; fail: posix_acl_release(acl); return ERR_PTR(-EINVAL); } /* * Convert from in-memory to filesystem representation. */ static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size) { reiserfs_acl_header *ext_acl; char *e; int n; *size = reiserfs_acl_size(acl->a_count); ext_acl = kmalloc(sizeof(reiserfs_acl_header) + acl->a_count * sizeof(reiserfs_acl_entry), GFP_NOFS); if (!ext_acl) return ERR_PTR(-ENOMEM); ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); e = (char *)ext_acl + sizeof(reiserfs_acl_header); for (n = 0; n < acl->a_count; n++) { reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER: case ACL_GROUP: entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); e += sizeof(reiserfs_acl_entry); break; case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: e += sizeof(reiserfs_acl_entry_short); break; default: goto fail; } } return (char *)ext_acl; fail: kfree(ext_acl); return ERR_PTR(-EINVAL); } /* * Inode operation get_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) { char *name, *value; struct posix_acl *acl; int size; int retval; acl = get_cached_acl(inode, type); if (acl != ACL_NOT_CACHED) return acl; switch (type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; break; default: BUG(); } size = reiserfs_xattr_get(inode, name, NULL, 0); if (size < 0) { if (size == -ENODATA || size == -ENOSYS) { set_cached_acl(inode, type, NULL); return NULL; } return ERR_PTR(size); } value = kmalloc(size, GFP_NOFS); if (!value) return ERR_PTR(-ENOMEM); retval = reiserfs_xattr_get(inode, name, value, size); if (retval == -ENODATA || retval == -ENOSYS) { /* This shouldn't actually happen as it should have been caught above.. but just in case */ acl = NULL; } else if (retval < 0) { acl = ERR_PTR(retval); } else { acl = posix_acl_from_disk(value, retval); } if (!IS_ERR(acl)) set_cached_acl(inode, type, acl); kfree(value); return acl; } /* * Inode operation set_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ static int reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, int type, struct posix_acl *acl) { char *name; void *value = NULL; size_t size = 0; int error; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; switch (type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; if (acl) { mode_t mode = inode->i_mode; error = posix_acl_equiv_mode(acl, &mode); if (error < 0) return error; else { inode->i_mode = mode; if (error == 0) acl = NULL; } } break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; if (!S_ISDIR(inode->i_mode)) return acl ? -EACCES : 0; break; default: return -EINVAL; } if (acl) { value = posix_acl_to_disk(acl, &size); if (IS_ERR(value)) return (int)PTR_ERR(value); } error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); /* * Ensure that the inode gets dirtied if we're only using * the mode bits and an old ACL didn't exist. We don't need * to check if the inode is hashed here since we won't get * called by reiserfs_inherit_default_acl(). */ if (error == -ENODATA) { error = 0; if (type == ACL_TYPE_ACCESS) { inode->i_ctime = CURRENT_TIME_SEC; mark_inode_dirty(inode); } } kfree(value); if (!error) set_cached_acl(inode, type, acl); return error; } /* dir->i_mutex: locked, * inode is new and not released into the wild yet */ int reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, struct inode *dir, struct dentry *dentry, struct inode *inode) { struct posix_acl *acl; int err = 0; /* ACLs only get applied to files and directories */ if (S_ISLNK(inode->i_mode)) return 0; /* ACLs can only be used on "new" objects, so if it's an old object * there is nothing to inherit from */ if (get_inode_sd_version(dir) == STAT_DATA_V1) goto apply_umask; /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This * would be useless since permissions are ignored, and a pain because * it introduces locking cycles */ if (IS_PRIVATE(dir)) { inode->i_flags |= S_PRIVATE; goto apply_umask; } acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { struct posix_acl *acl_copy; mode_t mode = inode->i_mode; int need_acl; /* Copy the default ACL to the default ACL of a new directory */ if (S_ISDIR(inode->i_mode)) { err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, acl); if (err) goto cleanup; } /* Now we reconcile the new ACL and the mode, potentially modifying both */ acl_copy = posix_acl_clone(acl, GFP_NOFS); if (!acl_copy) { err = -ENOMEM; goto cleanup; } need_acl = posix_acl_create_masq(acl_copy, &mode); if (need_acl >= 0) { if (mode != inode->i_mode) { inode->i_mode = mode; } /* If we need an ACL.. */ if (need_acl > 0) { err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl_copy); if (err) goto cleanup_copy; } } cleanup_copy: posix_acl_release(acl_copy); cleanup: posix_acl_release(acl); } else { apply_umask: /* no ACL, apply umask */ inode->i_mode &= ~current_umask(); } return err; } /* This is used to cache the default acl before a new object is created. * The biggest reason for this is to get an idea of how many blocks will * actually be required for the create operation if we must inherit an ACL. * An ACL write can add up to 3 object creations and an additional file write * so we'd prefer not to reserve that many blocks in the journal if we can. * It also has the advantage of not loading the ACL with a transaction open, * this may seem silly, but if the owner of the directory is doing the * creation, the ACL may not be loaded since the permissions wouldn't require * it. * We return the number of blocks required for the transaction. */ int reiserfs_cache_default_acl(struct inode *inode) { struct posix_acl *acl; int nblocks = 0; if (IS_PRIVATE(inode)) return 0; acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); if (acl && !IS_ERR(acl)) { int size = reiserfs_acl_size(acl->a_count); /* Other xattrs can be created during inode creation. We don't * want to claim too many blocks, so we check to see if we * we need to create the tree to the xattrs, and then we * just want two files. */ nblocks = reiserfs_xattr_jcreate_nblocks(inode); nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); REISERFS_I(inode)->i_flags |= i_has_xattr_dir; /* We need to account for writes + bitmaps for two files */ nblocks += reiserfs_xattr_nblocks(inode, size) * 4; posix_acl_release(acl); } return nblocks; } int reiserfs_acl_chmod(struct inode *inode) { struct posix_acl *acl, *clone; int error; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; if (get_inode_sd_version(inode) == STAT_DATA_V1 || !reiserfs_posixacl(inode->i_sb)) { return 0; } reiserfs_write_unlock(inode->i_sb); acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); reiserfs_write_lock(inode->i_sb); if (!acl) return 0; if (IS_ERR(acl)) return PTR_ERR(acl); clone = posix_acl_clone(acl, GFP_NOFS); posix_acl_release(acl); if (!clone) return -ENOMEM; error = posix_acl_chmod_masq(clone, inode->i_mode); if (!error) { struct reiserfs_transaction_handle th; size_t size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(clone->a_count)); reiserfs_write_lock(inode->i_sb); error = journal_begin(&th, inode->i_sb, size * 2); if (!error) { int error2; error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, clone); error2 = journal_end(&th, inode->i_sb, size * 2); if (error2) error = error2; } reiserfs_write_unlock(inode->i_sb); } posix_acl_release(clone); return error; } static size_t posix_acl_access_list(struct dentry *dentry, char *list, size_t list_size, const char *name, size_t name_len, int type) { const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); if (!reiserfs_posixacl(dentry->d_sb)) return 0; if (list && size <= list_size) memcpy(list, POSIX_ACL_XATTR_ACCESS, size); return size; } struct xattr_handler reiserfs_posix_acl_access_handler = { .prefix = POSIX_ACL_XATTR_ACCESS, .flags = ACL_TYPE_ACCESS, .get = posix_acl_get, .set = posix_acl_set, .list = posix_acl_access_list, }; static size_t posix_acl_default_list(struct dentry *dentry, char *list, size_t list_size, const char *name, size_t name_len, int type) { const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); if (!reiserfs_posixacl(dentry->d_sb)) return 0; if (list && size <= list_size) memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); return size; } struct xattr_handler reiserfs_posix_acl_default_handler = { .prefix = POSIX_ACL_XATTR_DEFAULT, .flags = ACL_TYPE_DEFAULT, .get = posix_acl_get, .set = posix_acl_set, .list = posix_acl_default_list, };