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 #include "nfs3_fs.h"
  11
  12 #define NFSDBG_FACILITY NFSDBG_PROC
  13
  14 struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
  15 {
  16         struct nfs_server *server = NFS_SERVER(inode);
  17         struct page *pages[NFSACL_MAXPAGES] = { };
  18         struct nfs3_getaclargs args = {
  19                 .fh = NFS_FH(inode),
  20                 /* The xdr layer may allocate pages here. */
  21                 .pages = pages,
  22         };
  23         struct nfs3_getaclres res = {
  24                 NULL,
  25         };
  26         struct rpc_message msg = {
  27                 .rpc_argp       = &args,
  28                 .rpc_resp       = &res,
  29         };
  30         int status, count;
  31
  32         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
  33                 return ERR_PTR(-EOPNOTSUPP);
  34
  35         status = nfs_revalidate_inode(server, inode);
  36         if (status < 0)
  37                 return ERR_PTR(status);
  38
  39         /*
  40          * Only get the access acl when explicitly requested: We don't
  41          * need it for access decisions, and only some applications use
  42          * it. Applications which request the access acl first are not
  43          * penalized from this optimization.
  44          */
  45         if (type == ACL_TYPE_ACCESS)
  46                 args.mask |= NFS_ACLCNT|NFS_ACL;
  47         if (S_ISDIR(inode->i_mode))
  48                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
  49         if (args.mask == 0)
  50                 return NULL;
  51
  52         dprintk("NFS call getacl\n");
  53         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
  54         res.fattr = nfs_alloc_fattr();
  55         if (res.fattr == NULL)
  56                 return ERR_PTR(-ENOMEM);
  57
  58         status = rpc_call_sync(server->client_acl, &msg, 0);
  59         dprintk("NFS reply getacl: %d\n", status);
  60
  61         /* pages may have been allocated at the xdr layer. */
  62         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
  63                 __free_page(args.pages[count]);
  64
  65         switch (status) {
  66                 case 0:
  67                         status = nfs_refresh_inode(inode, res.fattr);
  68                         break;
  69                 case -EPFNOSUPPORT:
  70                 case -EPROTONOSUPPORT:
  71                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
  72                         server->caps &= ~NFS_CAP_ACLS;
  73                 case -ENOTSUPP:
  74                         status = -EOPNOTSUPP;
  75                 default:
  76                         goto getout;
  77         }
  78         if ((args.mask & res.mask) != args.mask) {
  79                 status = -EIO;
  80                 goto getout;
  81         }
  82
  83         if (res.acl_access != NULL) {
  84                 if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
  85                     res.acl_access->a_count == 0) {
  86                         posix_acl_release(res.acl_access);
  87                         res.acl_access = NULL;
  88                 }
  89         }
  90
  91         if (res.mask & NFS_ACL)
  92                 set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
  93         else
  94                 forget_cached_acl(inode, ACL_TYPE_ACCESS);
  95
  96         if (res.mask & NFS_DFACL)
  97                 set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
  98         else
  99                 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
 100
 101         nfs_free_fattr(res.fattr);
 102         if (type == ACL_TYPE_ACCESS) {
 103                 posix_acl_release(res.acl_default);
 104                 return res.acl_access;
 105         } else {
 106                 posix_acl_release(res.acl_access);
 107                 return res.acl_default;
 108         }
 109
 110 getout:
 111         posix_acl_release(res.acl_access);
 112         posix_acl_release(res.acl_default);
 113         nfs_free_fattr(res.fattr);
 114         return ERR_PTR(status);
 115 }
 116
 117 static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 118                 struct posix_acl *dfacl)
 119 {
 120         struct nfs_server *server = NFS_SERVER(inode);
 121         struct nfs_fattr *fattr;
 122         struct page *pages[NFSACL_MAXPAGES];
 123         struct nfs3_setaclargs args = {
 124                 .inode = inode,
 125                 .mask = NFS_ACL,
 126                 .acl_access = acl,
 127                 .pages = pages,
 128         };
 129         struct rpc_message msg = {
 130                 .rpc_argp       = &args,
 131                 .rpc_resp       = &fattr,
 132         };
 133         int status = 0;
 134
 135         if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
 136                 goto out;
 137
 138         status = -EOPNOTSUPP;
 139         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 140                 goto out;
 141
 142         /* We are doing this here because XDR marshalling does not
 143          * return any results, it BUGs. */
 144         status = -ENOSPC;
 145         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 146                 goto out;
 147         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 148                 goto out;
 149         if (S_ISDIR(inode->i_mode)) {
 150                 args.mask |= NFS_DFACL;
 151                 args.acl_default = dfacl;
 152                 args.len = nfsacl_size(acl, dfacl);
 153         } else
 154                 args.len = nfsacl_size(acl, NULL);
 155
 156         if (args.len > NFS_ACL_INLINE_BUFSIZE) {
 157                 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
 158
 159                 status = -ENOMEM;
 160                 do {
 161                         args.pages[args.npages] = alloc_page(GFP_KERNEL);
 162                         if (args.pages[args.npages] == NULL)
 163                                 goto out_freepages;
 164                         args.npages++;
 165                 } while (args.npages < npages);
 166         }
 167
 168         dprintk("NFS call setacl\n");
 169         status = -ENOMEM;
 170         fattr = nfs_alloc_fattr();
 171         if (fattr == NULL)
 172                 goto out_freepages;
 173
 174         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 175         msg.rpc_resp = fattr;
 176         status = rpc_call_sync(server->client_acl, &msg, 0);
 177         nfs_access_zap_cache(inode);
 178         nfs_zap_acl_cache(inode);
 179         dprintk("NFS reply setacl: %d\n", status);
 180
 181         switch (status) {
 182                 case 0:
 183                         status = nfs_refresh_inode(inode, fattr);
 184                         set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
 185                         set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
 186                         break;
 187                 case -EPFNOSUPPORT:
 188                 case -EPROTONOSUPPORT:
 189                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 190                                         "(will not retry)\n");
 191                         server->caps &= ~NFS_CAP_ACLS;
 192                 case -ENOTSUPP:
 193                         status = -EOPNOTSUPP;
 194         }
 195         nfs_free_fattr(fattr);
 196 out_freepages:
 197         while (args.npages != 0) {
 198                 args.npages--;
 199                 __free_page(args.pages[args.npages]);
 200         }
 201 out:
 202         return status;
 203 }
 204
 205 int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 206                 struct posix_acl *dfacl)
 207 {
 208         int ret;
 209         ret = __nfs3_proc_setacls(inode, acl, dfacl);
 210         return (ret == -EOPNOTSUPP) ? 0 : ret;
 211
 212 }
 213
 214 int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 215 {
 216         struct posix_acl *orig = acl, *dfacl = NULL, *alloc;
 217         int status;
 218
 219         if (S_ISDIR(inode->i_mode)) {
 220                 switch(type) {
 221                 case ACL_TYPE_ACCESS:
 222                         alloc = get_acl(inode, ACL_TYPE_DEFAULT);
 223                         if (IS_ERR(alloc))
 224                                 goto fail;
 225                         dfacl = alloc;
 226                         break;
 227
 228                 case ACL_TYPE_DEFAULT:
 229                         alloc = get_acl(inode, ACL_TYPE_ACCESS);
 230                         if (IS_ERR(alloc))
 231                                 goto fail;
 232                         dfacl = acl;
 233                         acl = alloc;
 234                         break;
 235                 }
 236         }
 237
 238         if (acl == NULL) {
 239                 alloc = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 240                 if (IS_ERR(alloc))
 241                         goto fail;
 242                 acl = alloc;
 243         }
 244         status = __nfs3_proc_setacls(inode, acl, dfacl);
 245 out:
 246         if (acl != orig)
 247                 posix_acl_release(acl);
 248         if (dfacl != orig)
 249                 posix_acl_release(dfacl);
 250         return status;
 251
 252 fail:
 253         status = PTR_ERR(alloc);
 254         goto out;
 255 }
 256
 257 const struct xattr_handler *nfs3_xattr_handlers[] = {
 258         &posix_acl_access_xattr_handler,
 259         &posix_acl_default_xattr_handler,
 260         NULL,
 261 };
 262
 263 static int
 264 nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
 265                 size_t size, ssize_t *result)
 266 {
 267         struct posix_acl *acl;
 268         char *p = data + *result;
 269
 270         acl = get_acl(inode, type);
 271         if (IS_ERR_OR_NULL(acl))
 272                 return 0;
 273
 274         posix_acl_release(acl);
 275
 276         *result += strlen(name);
 277         *result += 1;
 278         if (!size)
 279                 return 0;
 280         if (*result > size)
 281                 return -ERANGE;
 282
 283         strcpy(p, name);
 284         return 0;
 285 }
 286
 287 ssize_t
 288 nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
 289 {
 290         struct inode *inode = d_inode(dentry);
 291         ssize_t result = 0;
 292         int error;
 293
 294         error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
 295                         POSIX_ACL_XATTR_ACCESS, data, size, &result);
 296         if (error)
 297                 return error;
 298
 299         error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
 300                         POSIX_ACL_XATTR_DEFAULT, data, size, &result);
 301         if (error)
 302                 return error;
 303         return result;
 304 }