fs/nfs/nfs3acl.c

   1 #include <linux/fs.h>
   2 #include <linux/gfp.h>
   3 #include <linux/nfs.h>
   4 #include <linux/nfs3.h>
   5 #include <linux/nfs_fs.h>
   6 #include <linux/posix_acl_xattr.h>
   7 #include <linux/nfsacl.h>
   8
   9 #include "internal.h"
  10
  11 #define NFSDBG_FACILITY NFSDBG_PROC
  12
  13 struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
  14 {
  15         struct nfs_server *server = NFS_SERVER(inode);
  16         struct page *pages[NFSACL_MAXPAGES] = { };
  17         struct nfs3_getaclargs args = {
  18                 .fh = NFS_FH(inode),
  19                 /* The xdr layer may allocate pages here. */
  20                 .pages = pages,
  21         };
  22         struct nfs3_getaclres res = {
  23                 NULL,
  24         };
  25         struct rpc_message msg = {
  26                 .rpc_argp       = &args,
  27                 .rpc_resp       = &res,
  28         };
  29         int status, count;
  30
  31         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
  32                 return ERR_PTR(-EOPNOTSUPP);
  33
  34         status = nfs_revalidate_inode(server, inode);
  35         if (status < 0)
  36                 return ERR_PTR(status);
  37
  38         /*
  39          * Only get the access acl when explicitly requested: We don't
  40          * need it for access decisions, and only some applications use
  41          * it. Applications which request the access acl first are not
  42          * penalized from this optimization.
  43          */
  44         if (type == ACL_TYPE_ACCESS)
  45                 args.mask |= NFS_ACLCNT|NFS_ACL;
  46         if (S_ISDIR(inode->i_mode))
  47                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
  48         if (args.mask == 0)
  49                 return NULL;
  50
  51         dprintk("NFS call getacl\n");
  52         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
  53         res.fattr = nfs_alloc_fattr();
  54         if (res.fattr == NULL)
  55                 return ERR_PTR(-ENOMEM);
  56
  57         status = rpc_call_sync(server->client_acl, &msg, 0);
  58         dprintk("NFS reply getacl: %d\n", status);
  59
  60         /* pages may have been allocated at the xdr layer. */
  61         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
  62                 __free_page(args.pages[count]);
  63
  64         switch (status) {
  65                 case 0:
  66                         status = nfs_refresh_inode(inode, res.fattr);
  67                         break;
  68                 case -EPFNOSUPPORT:
  69                 case -EPROTONOSUPPORT:
  70                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
  71                         server->caps &= ~NFS_CAP_ACLS;
  72                 case -ENOTSUPP:
  73                         status = -EOPNOTSUPP;
  74                 default:
  75                         goto getout;
  76         }
  77         if ((args.mask & res.mask) != args.mask) {
  78                 status = -EIO;
  79                 goto getout;
  80         }
  81
  82         if (res.acl_access != NULL) {
  83                 if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
  84                     res.acl_access->a_count == 0) {
  85                         posix_acl_release(res.acl_access);
  86                         res.acl_access = NULL;
  87                 }
  88         }
  89
  90         if (res.mask & NFS_ACL)
  91                 set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
  92         else
  93                 forget_cached_acl(inode, ACL_TYPE_ACCESS);
  94
  95         if (res.mask & NFS_DFACL)
  96                 set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
  97         else
  98                 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
  99
 100         nfs_free_fattr(res.fattr);
 101         if (type == ACL_TYPE_ACCESS) {
 102                 posix_acl_release(res.acl_default);
 103                 return res.acl_access;
 104         } else {
 105                 posix_acl_release(res.acl_access);
 106                 return res.acl_default;
 107         }
 108
 109 getout:
 110         posix_acl_release(res.acl_access);
 111         posix_acl_release(res.acl_default);
 112         nfs_free_fattr(res.fattr);
 113         return ERR_PTR(status);
 114 }
 115
 116 static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 117                 struct posix_acl *dfacl)
 118 {
 119         struct nfs_server *server = NFS_SERVER(inode);
 120         struct nfs_fattr *fattr;
 121         struct page *pages[NFSACL_MAXPAGES];
 122         struct nfs3_setaclargs args = {
 123                 .inode = inode,
 124                 .mask = NFS_ACL,
 125                 .acl_access = acl,
 126                 .pages = pages,
 127         };
 128         struct rpc_message msg = {
 129                 .rpc_argp       = &args,
 130                 .rpc_resp       = &fattr,
 131         };
 132         int status;
 133
 134         status = -EOPNOTSUPP;
 135         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 136                 goto out;
 137
 138         /* We are doing this here because XDR marshalling does not
 139          * return any results, it BUGs. */
 140         status = -ENOSPC;
 141         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 142                 goto out;
 143         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 144                 goto out;
 145         if (S_ISDIR(inode->i_mode)) {
 146                 args.mask |= NFS_DFACL;
 147                 args.acl_default = dfacl;
 148                 args.len = nfsacl_size(acl, dfacl);
 149         } else
 150                 args.len = nfsacl_size(acl, NULL);
 151
 152         if (args.len > NFS_ACL_INLINE_BUFSIZE) {
 153                 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
 154
 155                 status = -ENOMEM;
 156                 do {
 157                         args.pages[args.npages] = alloc_page(GFP_KERNEL);
 158                         if (args.pages[args.npages] == NULL)
 159                                 goto out_freepages;
 160                         args.npages++;
 161                 } while (args.npages < npages);
 162         }
 163
 164         dprintk("NFS call setacl\n");
 165         status = -ENOMEM;
 166         fattr = nfs_alloc_fattr();
 167         if (fattr == NULL)
 168                 goto out_freepages;
 169
 170         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 171         msg.rpc_resp = fattr;
 172         status = rpc_call_sync(server->client_acl, &msg, 0);
 173         nfs_access_zap_cache(inode);
 174         nfs_zap_acl_cache(inode);
 175         dprintk("NFS reply setacl: %d\n", status);
 176
 177         switch (status) {
 178                 case 0:
 179                         status = nfs_refresh_inode(inode, fattr);
 180                         set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
 181                         set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
 182                         break;
 183                 case -EPFNOSUPPORT:
 184                 case -EPROTONOSUPPORT:
 185                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 186                                         "(will not retry)\n");
 187                         server->caps &= ~NFS_CAP_ACLS;
 188                 case -ENOTSUPP:
 189                         status = -EOPNOTSUPP;
 190         }
 191         nfs_free_fattr(fattr);
 192 out_freepages:
 193         while (args.npages != 0) {
 194                 args.npages--;
 195                 __free_page(args.pages[args.npages]);
 196         }
 197 out:
 198         return status;
 199 }
 200
 201 int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 202                 struct posix_acl *dfacl)
 203 {
 204         int ret;
 205         ret = __nfs3_proc_setacls(inode, acl, dfacl);
 206         return (ret == -EOPNOTSUPP) ? 0 : ret;
 207
 208 }
 209
 210 int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 211 {
 212         struct posix_acl *alloc = NULL, *dfacl = NULL;
 213         int status;
 214
 215         if (S_ISDIR(inode->i_mode)) {
 216                 switch(type) {
 217                 case ACL_TYPE_ACCESS:
 218                         alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
 219                         if (IS_ERR(alloc))
 220                                 goto fail;
 221                         break;
 222
 223                 case ACL_TYPE_DEFAULT:
 224                         dfacl = acl;
 225                         alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
 226                         if (IS_ERR(alloc))
 227                                 goto fail;
 228                         break;
 229                 }
 230         }
 231
 232         if (acl == NULL) {
 233                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 234                 if (IS_ERR(alloc))
 235                         goto fail;
 236         }
 237         status = __nfs3_proc_setacls(inode, acl, dfacl);
 238         posix_acl_release(alloc);
 239         return status;
 240
 241 fail:
 242         return PTR_ERR(alloc);
 243 }
 244
 245 const struct xattr_handler *nfs3_xattr_handlers[] = {
 246         &posix_acl_access_xattr_handler,
 247         &posix_acl_default_xattr_handler,
 248         NULL,
 249 };
 250
 251 static int
 252 nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
 253                 size_t size, ssize_t *result)
 254 {
 255         struct posix_acl *acl;
 256         char *p = data + *result;
 257
 258         acl = get_acl(inode, type);
 259         if (IS_ERR_OR_NULL(acl))
 260                 return 0;
 261
 262         posix_acl_release(acl);
 263
 264         *result += strlen(name);
 265         *result += 1;
 266         if (!size)
 267                 return 0;
 268         if (*result > size)
 269                 return -ERANGE;
 270
 271         strcpy(p, name);
 272         return 0;
 273 }
 274
 275 ssize_t
 276 nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
 277 {
 278         struct inode *inode = dentry->d_inode;
 279         ssize_t result = 0;
 280         int error;
 281
 282         error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
 283                         POSIX_ACL_XATTR_ACCESS, data, size, &result);
 284         if (error)
 285                 return error;
 286
 287         error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
 288                         POSIX_ACL_XATTR_DEFAULT, data, size, &result);
 289         if (error)
 290                 return error;
 291         return result;
 292 }