drivers/staging/lustre/lustre/lvfs/lvfs_linux.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/lvfs/lvfs_linux.c
  37  *
  38  * Author: Andreas Dilger <adilger@clusterfs.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_FILTER
  42
  43 #include <linux/fs.h>
  44 #include <asm/unistd.h>
  45 #include <linux/slab.h>
  46 #include <linux/pagemap.h>
  47 #include <linux/quotaops.h>
  48 #include <linux/libcfs/libcfs.h>
  49 #include <linux/module.h>
  50 #include <linux/init.h>
  51 #include <linux/lustre_compat25.h>
  52 #include <lvfs.h>
  53
  54 #include <obd.h>
  55 #include <lustre_lib.h>
  56
  57 struct lprocfs_stats *obd_memory = NULL;
  58 EXPORT_SYMBOL(obd_memory);
  59 /* refine later and change to seqlock or simlar from libcfs */
  60
  61 /* Debugging check only needed during development */
  62 #ifdef OBD_CTXT_DEBUG
  63 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  64 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  65                                               msg)
  66 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  67 #else
  68 # define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  69 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  70 # define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  71 #endif
  72
  73 static void push_group_info(struct lvfs_run_ctxt *save,
  74                             struct group_info *ginfo)
  75 {
  76         if (!ginfo) {
  77                 save->ngroups = current_ngroups;
  78                 current_ngroups = 0;
  79         } else {
  80                 struct cred *cred;
  81                 task_lock(current);
  82                 save->group_info = current_cred()->group_info;
  83                 if ((cred = prepare_creds())) {
  84                         cred->group_info = ginfo;
  85                         commit_creds(cred);
  86                 }
  87                 task_unlock(current);
  88         }
  89 }
  90
  91 static void pop_group_info(struct lvfs_run_ctxt *save,
  92                            struct group_info *ginfo)
  93 {
  94         if (!ginfo) {
  95                 current_ngroups = save->ngroups;
  96         } else {
  97                 struct cred *cred;
  98                 task_lock(current);
  99                 if ((cred = prepare_creds())) {
 100                         cred->group_info = save->group_info;
 101                         commit_creds(cred);
 102                 }
 103                 task_unlock(current);
 104         }
 105 }
 106
 107 /* push / pop to root of obd store */
 108 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 109                struct lvfs_ucred *uc)
 110 {
 111         /* if there is underlaying dt_device then push_ctxt is not needed */
 112         if (new_ctx->dt != NULL)
 113                 return;
 114
 115         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
 116         ASSERT_CTXT_MAGIC(new_ctx->magic);
 117         OBD_SET_CTXT_MAGIC(save);
 118
 119         save->fs = get_fs();
 120         LASSERT(d_count(cfs_fs_pwd(current->fs)));
 121         LASSERT(d_count(new_ctx->pwd));
 122         save->pwd = dget(cfs_fs_pwd(current->fs));
 123         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 124         save->luc.luc_umask = current_umask();
 125         save->ngroups = current_cred()->group_info->ngroups;
 126
 127         LASSERT(save->pwd);
 128         LASSERT(save->pwdmnt);
 129         LASSERT(new_ctx->pwd);
 130         LASSERT(new_ctx->pwdmnt);
 131
 132         if (uc) {
 133                 struct cred *cred;
 134                 save->luc.luc_uid = current_uid();
 135                 save->luc.luc_gid = current_gid();
 136                 save->luc.luc_fsuid = current_fsuid();
 137                 save->luc.luc_fsgid = current_fsgid();
 138                 save->luc.luc_cap = current_cap();
 139
 140                 if ((cred = prepare_creds())) {
 141                         cred->uid = uc->luc_uid;
 142                         cred->gid = uc->luc_gid;
 143                         cred->fsuid = uc->luc_fsuid;
 144                         cred->fsgid = uc->luc_fsgid;
 145                         cred->cap_effective = uc->luc_cap;
 146                         commit_creds(cred);
 147                 }
 148
 149                 push_group_info(save,
 150                                 uc->luc_ginfo ?:
 151                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 152                                                    NULL);
 153         }
 154         current->fs->umask = 0; /* umask already applied on client */
 155         set_fs(new_ctx->fs);
 156         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 157 }
 158 EXPORT_SYMBOL(push_ctxt);
 159
 160 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 161               struct lvfs_ucred *uc)
 162 {
 163         /* if there is underlaying dt_device then pop_ctxt is not needed */
 164         if (new_ctx->dt != NULL)
 165                 return;
 166
 167         ASSERT_CTXT_MAGIC(saved->magic);
 168         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 169
 170         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 171                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 172         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 173                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 174
 175         set_fs(saved->fs);
 176         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 177
 178         dput(saved->pwd);
 179         mntput(saved->pwdmnt);
 180         current->fs->umask = saved->luc.luc_umask;
 181         if (uc) {
 182                 struct cred *cred;
 183                 if ((cred = prepare_creds())) {
 184                         cred->uid = saved->luc.luc_uid;
 185                         cred->gid = saved->luc.luc_gid;
 186                         cred->fsuid = saved->luc.luc_fsuid;
 187                         cred->fsgid = saved->luc.luc_fsgid;
 188                         cred->cap_effective = saved->luc.luc_cap;
 189                         commit_creds(cred);
 190                 }
 191
 192                 pop_group_info(saved,
 193                                uc->luc_ginfo ?:
 194                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 195                                                   NULL);
 196         }
 197 }
 198 EXPORT_SYMBOL(pop_ctxt);
 199
 200 /* utility to rename a file */
 201 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 202                   char *oldname, char *newname)
 203 {
 204         struct dentry *dchild_old, *dchild_new;
 205         int err = 0;
 206
 207         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 208         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 209                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 210
 211         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 212         if (IS_ERR(dchild_old))
 213                 return PTR_ERR(dchild_old);
 214
 215         if (!dchild_old->d_inode)
 216                 GOTO(put_old, err = -ENOENT);
 217
 218         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 219         if (IS_ERR(dchild_new))
 220                 GOTO(put_old, err = PTR_ERR(dchild_new));
 221
 222         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 223                             dir->d_inode, dchild_new, mnt);
 224
 225         dput(dchild_new);
 226 put_old:
 227         dput(dchild_old);
 228         return err;
 229 }
 230 EXPORT_SYMBOL(lustre_rename);
 231
 232 /* Note: dput(dchild) will *not* be called if there is an error */
 233 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 234                              int flags)
 235 {
 236         struct path path = {
 237                 .dentry = de,
 238                 .mnt = ctxt->pwdmnt,
 239         };
 240         return dentry_open(&path, flags, current_cred());
 241 }
 242 EXPORT_SYMBOL(l_dentry_open);
 243
 244 #ifdef LPROCFS
 245 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 246                           struct lprocfs_counter_header *header,
 247                           enum lprocfs_stats_flags flags,
 248                           enum lprocfs_fields_flags field)
 249 {
 250         __s64 ret = 0;
 251
 252         if (lc == NULL || header == NULL)
 253                 return 0;
 254
 255         switch (field) {
 256                 case LPROCFS_FIELDS_FLAGS_CONFIG:
 257                         ret = header->lc_config;
 258                         break;
 259                 case LPROCFS_FIELDS_FLAGS_SUM:
 260                         ret = lc->lc_sum;
 261                         if ((flags & LPROCFS_STATS_FLAG_IRQ_SAFE) != 0)
 262                                 ret += lc->lc_sum_irq;
 263                         break;
 264                 case LPROCFS_FIELDS_FLAGS_MIN:
 265                         ret = lc->lc_min;
 266                         break;
 267                 case LPROCFS_FIELDS_FLAGS_MAX:
 268                         ret = lc->lc_max;
 269                         break;
 270                 case LPROCFS_FIELDS_FLAGS_AVG:
 271                         ret = (lc->lc_max - lc->lc_min) / 2;
 272                         break;
 273                 case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 274                         ret = lc->lc_sumsquare;
 275                         break;
 276                 case LPROCFS_FIELDS_FLAGS_COUNT:
 277                         ret = lc->lc_count;
 278                         break;
 279                 default:
 280                         break;
 281         };
 282
 283         return ret;
 284 }
 285 EXPORT_SYMBOL(lprocfs_read_helper);
 286 #endif /* LPROCFS */
 287
 288 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 289 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 290 MODULE_LICENSE("GPL");