Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | // SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Red Hat. All rights reserved. */ #include <linux/fs.h> #include <linux/string.h> #include <linux/xattr.h> #include <linux/posix_acl_xattr.h> #include <linux/posix_acl.h> #include <linux/sched.h> #include <linux/sched/mm.h> #include <linux/slab.h> #include "ctree.h" #include "btrfs_inode.h" #include "xattr.h" struct posix_acl *btrfs_get_acl(struct inode *inode, int type) { int size; const char *name; char *value = NULL; struct posix_acl *acl; switch (type) { case ACL_TYPE_ACCESS: name = XATTR_NAME_POSIX_ACL_ACCESS; break; case ACL_TYPE_DEFAULT: name = XATTR_NAME_POSIX_ACL_DEFAULT; break; default: return ERR_PTR(-EINVAL); } size = btrfs_getxattr(inode, name, NULL, 0); if (size > 0) { value = kzalloc(size, GFP_KERNEL); if (!value) return ERR_PTR(-ENOMEM); size = btrfs_getxattr(inode, name, value, size); } if (size > 0) acl = posix_acl_from_xattr(&init_user_ns, value, size); else if (size == -ENODATA || size == 0) acl = NULL; else acl = ERR_PTR(size); kfree(value); return acl; } static int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode, struct posix_acl *acl, int type) { int ret, size = 0; const char *name; char *value = NULL; switch (type) { case ACL_TYPE_ACCESS: name = XATTR_NAME_POSIX_ACL_ACCESS; break; case ACL_TYPE_DEFAULT: if (!S_ISDIR(inode->i_mode)) return acl ? -EINVAL : 0; name = XATTR_NAME_POSIX_ACL_DEFAULT; break; default: return -EINVAL; } if (acl) { unsigned int nofs_flag; size = posix_acl_xattr_size(acl->a_count); /* * We're holding a transaction handle, so use a NOFS memory * allocation context to avoid deadlock if reclaim happens. */ nofs_flag = memalloc_nofs_save(); value = kmalloc(size, GFP_KERNEL); memalloc_nofs_restore(nofs_flag); if (!value) { ret = -ENOMEM; goto out; } ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); if (ret < 0) goto out; } if (trans) ret = btrfs_setxattr(trans, inode, name, value, size, 0); else ret = btrfs_setxattr_trans(inode, name, value, size, 0); out: kfree(value); if (!ret) set_cached_acl(inode, type, acl); return ret; } int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode, struct posix_acl *acl, int type) { int ret; umode_t old_mode = inode->i_mode; if (type == ACL_TYPE_ACCESS && acl) { ret = posix_acl_update_mode(&init_user_ns, inode, &inode->i_mode, &acl); if (ret) return ret; } ret = __btrfs_set_acl(NULL, inode, acl, type); if (ret) inode->i_mode = old_mode; return ret; } int btrfs_init_acl(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *dir) { struct posix_acl *default_acl, *acl; int ret = 0; /* this happens with subvols */ if (!dir) return 0; ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); if (ret) return ret; if (default_acl) { ret = __btrfs_set_acl(trans, inode, default_acl, ACL_TYPE_DEFAULT); posix_acl_release(default_acl); } if (acl) { if (!ret) ret = __btrfs_set_acl(trans, inode, acl, ACL_TYPE_ACCESS); posix_acl_release(acl); } if (!default_acl && !acl) cache_no_acl(inode); return ret; } |