346 lines · c
1// SPDX-License-Identifier: LGPL-2.12/*3 * Copyright IBM Corporation, 20104 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>5 */6 7#include <linux/module.h>8#include <linux/fs.h>9#include <net/9p/9p.h>10#include <net/9p/client.h>11#include <linux/slab.h>12#include <linux/sched.h>13#include <linux/posix_acl_xattr.h>14#include "xattr.h"15#include "acl.h"16#include "v9fs.h"17#include "v9fs_vfs.h"18#include "fid.h"19 20static struct posix_acl *v9fs_fid_get_acl(struct p9_fid *fid, const char *name)21{22 ssize_t size;23 void *value = NULL;24 struct posix_acl *acl = NULL;25 26 size = v9fs_fid_xattr_get(fid, name, NULL, 0);27 if (size < 0)28 return ERR_PTR(size);29 if (size == 0)30 return ERR_PTR(-ENODATA);31 32 value = kzalloc(size, GFP_NOFS);33 if (!value)34 return ERR_PTR(-ENOMEM);35 36 size = v9fs_fid_xattr_get(fid, name, value, size);37 if (size < 0)38 acl = ERR_PTR(size);39 else if (size == 0)40 acl = ERR_PTR(-ENODATA);41 else42 acl = posix_acl_from_xattr(&init_user_ns, value, size);43 kfree(value);44 return acl;45}46 47static struct posix_acl *v9fs_acl_get(struct dentry *dentry, const char *name)48{49 struct p9_fid *fid;50 struct posix_acl *acl = NULL;51 52 fid = v9fs_fid_lookup(dentry);53 if (IS_ERR(fid))54 return ERR_CAST(fid);55 56 acl = v9fs_fid_get_acl(fid, name);57 p9_fid_put(fid);58 return acl;59}60 61static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, const char *name)62{63 int retval;64 struct posix_acl *acl = NULL;65 66 acl = v9fs_fid_get_acl(fid, name);67 if (!IS_ERR(acl))68 return acl;69 70 retval = PTR_ERR(acl);71 if (retval == -ENODATA || retval == -ENOSYS || retval == -EOPNOTSUPP)72 return NULL;73 74 /* map everything else to -EIO */75 return ERR_PTR(-EIO);76}77 78int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)79{80 int retval = 0;81 struct posix_acl *pacl, *dacl;82 struct v9fs_session_info *v9ses;83 84 v9ses = v9fs_inode2v9ses(inode);85 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||86 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {87 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);88 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);89 return 0;90 }91 /* get the default/access acl values and cache them */92 dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT);93 pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS);94 95 if (!IS_ERR(dacl) && !IS_ERR(pacl)) {96 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);97 set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);98 } else99 retval = -EIO;100 101 if (!IS_ERR(dacl))102 posix_acl_release(dacl);103 104 if (!IS_ERR(pacl))105 posix_acl_release(pacl);106 107 return retval;108}109 110static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)111{112 struct posix_acl *acl;113 /*114 * 9p Always cache the acl value when115 * instantiating the inode (v9fs_inode_from_fid)116 */117 acl = get_cached_acl(inode, type);118 BUG_ON(is_uncached_acl(acl));119 return acl;120}121 122struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type, bool rcu)123{124 struct v9fs_session_info *v9ses;125 126 if (rcu)127 return ERR_PTR(-ECHILD);128 129 v9ses = v9fs_inode2v9ses(inode);130 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||131 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {132 /*133 * On access = client and acl = on mode get the acl134 * values from the server135 */136 return NULL;137 }138 return v9fs_get_cached_acl(inode, type);139 140}141 142struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap,143 struct dentry *dentry, int type)144{145 struct v9fs_session_info *v9ses;146 147 v9ses = v9fs_dentry2v9ses(dentry);148 /* We allow set/get/list of acl when access=client is not specified. */149 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)150 return v9fs_acl_get(dentry, posix_acl_xattr_name(type));151 return v9fs_get_cached_acl(d_inode(dentry), type);152}153 154int v9fs_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,155 struct posix_acl *acl, int type)156{157 int retval;158 size_t size = 0;159 void *value = NULL;160 const char *acl_name;161 struct v9fs_session_info *v9ses;162 struct inode *inode = d_inode(dentry);163 164 if (acl) {165 retval = posix_acl_valid(inode->i_sb->s_user_ns, acl);166 if (retval)167 goto err_out;168 169 size = posix_acl_xattr_size(acl->a_count);170 171 value = kzalloc(size, GFP_NOFS);172 if (!value) {173 retval = -ENOMEM;174 goto err_out;175 }176 177 retval = posix_acl_to_xattr(&init_user_ns, acl, value, size);178 if (retval < 0)179 goto err_out;180 }181 182 /*183 * set the attribute on the remote. Without even looking at the184 * xattr value. We leave it to the server to validate185 */186 acl_name = posix_acl_xattr_name(type);187 v9ses = v9fs_dentry2v9ses(dentry);188 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {189 retval = v9fs_xattr_set(dentry, acl_name, value, size, 0);190 goto err_out;191 }192 193 if (S_ISLNK(inode->i_mode)) {194 retval = -EOPNOTSUPP;195 goto err_out;196 }197 198 if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) {199 retval = -EPERM;200 goto err_out;201 }202 203 switch (type) {204 case ACL_TYPE_ACCESS:205 if (acl) {206 struct iattr iattr = {};207 struct posix_acl *acl_mode = acl;208 209 retval = posix_acl_update_mode(&nop_mnt_idmap, inode,210 &iattr.ia_mode,211 &acl_mode);212 if (retval)213 goto err_out;214 if (!acl_mode) {215 /*216 * ACL can be represented by the mode bits.217 * So don't update ACL below.218 */219 kfree(value);220 value = NULL;221 size = 0;222 }223 iattr.ia_valid = ATTR_MODE;224 /*225 * FIXME should we update ctime ?226 * What is the following setxattr update the mode ?227 */228 v9fs_vfs_setattr_dotl(&nop_mnt_idmap, dentry, &iattr);229 }230 break;231 case ACL_TYPE_DEFAULT:232 if (!S_ISDIR(inode->i_mode)) {233 retval = acl ? -EINVAL : 0;234 goto err_out;235 }236 break;237 }238 239 retval = v9fs_xattr_set(dentry, acl_name, value, size, 0);240 if (!retval)241 set_cached_acl(inode, type, acl);242 243err_out:244 kfree(value);245 return retval;246}247 248static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)249{250 int retval;251 char *name;252 size_t size;253 void *buffer;254 255 if (!acl)256 return 0;257 258 /* Set a setxattr request to server */259 size = posix_acl_xattr_size(acl->a_count);260 buffer = kmalloc(size, GFP_KERNEL);261 if (!buffer)262 return -ENOMEM;263 retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);264 if (retval < 0)265 goto err_free_out;266 switch (type) {267 case ACL_TYPE_ACCESS:268 name = XATTR_NAME_POSIX_ACL_ACCESS;269 break;270 case ACL_TYPE_DEFAULT:271 name = XATTR_NAME_POSIX_ACL_DEFAULT;272 break;273 default:274 BUG();275 }276 retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0);277err_free_out:278 kfree(buffer);279 return retval;280}281 282int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)283{284 int retval = 0;285 struct posix_acl *acl;286 287 if (S_ISLNK(inode->i_mode))288 return -EOPNOTSUPP;289 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);290 if (acl) {291 retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);292 if (retval)293 return retval;294 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);295 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);296 posix_acl_release(acl);297 }298 return retval;299}300 301int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,302 struct posix_acl *dacl, struct posix_acl *acl)303{304 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);305 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);306 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl);307 v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);308 return 0;309}310 311void v9fs_put_acl(struct posix_acl *dacl,312 struct posix_acl *acl)313{314 posix_acl_release(dacl);315 posix_acl_release(acl);316}317 318int v9fs_acl_mode(struct inode *dir, umode_t *modep,319 struct posix_acl **dpacl, struct posix_acl **pacl)320{321 int retval = 0;322 umode_t mode = *modep;323 struct posix_acl *acl = NULL;324 325 if (!S_ISLNK(mode)) {326 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);327 if (IS_ERR(acl))328 return PTR_ERR(acl);329 if (!acl)330 mode &= ~current_umask();331 }332 if (acl) {333 if (S_ISDIR(mode))334 *dpacl = posix_acl_dup(acl);335 retval = __posix_acl_create(&acl, GFP_NOFS, &mode);336 if (retval < 0)337 return retval;338 if (retval > 0)339 *pacl = acl;340 else341 posix_acl_release(acl);342 }343 *modep = mode;344 return 0;345}346