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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | /* * mm/shmem_acl.c * * (C) 2005 Andreas Gruenbacher <agruen@suse.de> * * This file is released under the GPL. */ #include <linux/fs.h> #include <linux/shmem_fs.h> #include <linux/xattr.h> #include <linux/generic_acl.h> /** * shmem_get_acl - generic_acl_operations->getacl() operation */ static struct posix_acl * shmem_get_acl(struct inode *inode, int type) { struct posix_acl *acl = NULL; spin_lock(&inode->i_lock); switch(type) { case ACL_TYPE_ACCESS: acl = posix_acl_dup(SHMEM_I(inode)->i_acl); break; case ACL_TYPE_DEFAULT: acl = posix_acl_dup(SHMEM_I(inode)->i_default_acl); break; } spin_unlock(&inode->i_lock); return acl; } /** * shmem_set_acl - generic_acl_operations->setacl() operation */ static void shmem_set_acl(struct inode *inode, int type, struct posix_acl *acl) { struct posix_acl *free = NULL; spin_lock(&inode->i_lock); switch(type) { case ACL_TYPE_ACCESS: free = SHMEM_I(inode)->i_acl; SHMEM_I(inode)->i_acl = posix_acl_dup(acl); break; case ACL_TYPE_DEFAULT: free = SHMEM_I(inode)->i_default_acl; SHMEM_I(inode)->i_default_acl = posix_acl_dup(acl); break; } spin_unlock(&inode->i_lock); posix_acl_release(free); } struct generic_acl_operations shmem_acl_ops = { .getacl = shmem_get_acl, .setacl = shmem_set_acl, }; /** * shmem_list_acl_access, shmem_get_acl_access, shmem_set_acl_access, * shmem_xattr_acl_access_handler - plumbing code to implement the * system.posix_acl_access xattr using the generic acl functions. */ static size_t shmem_list_acl_access(struct inode *inode, char *list, size_t list_size, const char *name, size_t name_len) { return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, list, list_size); } static int shmem_get_acl_access(struct inode *inode, const char *name, void *buffer, size_t size) { if (strcmp(name, "") != 0) return -EINVAL; return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, buffer, size); } static int shmem_set_acl_access(struct inode *inode, const char *name, const void *value, size_t size, int flags) { if (strcmp(name, "") != 0) return -EINVAL; return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, value, size); } struct xattr_handler shmem_xattr_acl_access_handler = { .prefix = POSIX_ACL_XATTR_ACCESS, .list = shmem_list_acl_access, .get = shmem_get_acl_access, .set = shmem_set_acl_access, }; /** * shmem_list_acl_default, shmem_get_acl_default, shmem_set_acl_default, * shmem_xattr_acl_default_handler - plumbing code to implement the * system.posix_acl_default xattr using the generic acl functions. */ static size_t shmem_list_acl_default(struct inode *inode, char *list, size_t list_size, const char *name, size_t name_len) { return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, list, list_size); } static int shmem_get_acl_default(struct inode *inode, const char *name, void *buffer, size_t size) { if (strcmp(name, "") != 0) return -EINVAL; return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, buffer, size); } static int shmem_set_acl_default(struct inode *inode, const char *name, const void *value, size_t size, int flags) { if (strcmp(name, "") != 0) return -EINVAL; return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, value, size); } struct xattr_handler shmem_xattr_acl_default_handler = { .prefix = POSIX_ACL_XATTR_DEFAULT, .list = shmem_list_acl_default, .get = shmem_get_acl_default, .set = shmem_set_acl_default, }; /** * shmem_acl_init - Inizialize the acl(s) of a new inode */ int shmem_acl_init(struct inode *inode, struct inode *dir) { return generic_acl_init(inode, dir, &shmem_acl_ops); } /** * shmem_acl_destroy_inode - destroy acls hanging off the in-memory inode * * This is done before destroying the actual inode. */ void shmem_acl_destroy_inode(struct inode *inode) { if (SHMEM_I(inode)->i_acl) posix_acl_release(SHMEM_I(inode)->i_acl); SHMEM_I(inode)->i_acl = NULL; if (SHMEM_I(inode)->i_default_acl) posix_acl_release(SHMEM_I(inode)->i_default_acl); SHMEM_I(inode)->i_default_acl = NULL; } /** * shmem_check_acl - check_acl() callback for generic_permission() */ static int shmem_check_acl(struct inode *inode, int mask) { struct posix_acl *acl = shmem_get_acl(inode, ACL_TYPE_ACCESS); if (acl) { int error = posix_acl_permission(inode, acl, mask); posix_acl_release(acl); return error; } return -EAGAIN; } /** * shmem_permission - permission() inode operation */ int shmem_permission(struct inode *inode, int mask, struct nameidata *nd) { return generic_permission(inode, mask, shmem_check_acl); } |