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/lustre_compat25.h>
  51 #include <lvfs.h>
  52
  53 #include <obd.h>
  54 #include <lustre_lib.h>
  55
  56 struct lprocfs_stats *obd_memory = NULL;
  57 EXPORT_SYMBOL(obd_memory);
  58 /* refine later and change to seqlock or simlar from libcfs */
  59
  60 /* Debugging check only needed during development */
  61 #ifdef OBD_CTXT_DEBUG
  62 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  63 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  64                                               msg)
  65 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  66 #else
  67 # define ASSERT_CTXT_MAGIC(magic) do {} while (0)
  68 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while (0)
  69 # define ASSERT_KERNEL_CTXT(msg) do {} while (0)
  70 #endif
  71
  72 static void push_group_info(struct lvfs_run_ctxt *save,
  73                             struct group_info *ginfo)
  74 {
  75         if (!ginfo) {
  76                 save->ngroups = current_ngroups;
  77                 current_ngroups = 0;
  78         } else {
  79                 struct cred *cred;
  80                 task_lock(current);
  81                 save->group_info = current_cred()->group_info;
  82                 cred = prepare_creds();
  83                 if (cred) {
  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                 cred = prepare_creds();
 100                 if (cred) {
 101                         cred->group_info = save->group_info;
 102                         commit_creds(cred);
 103                 }
 104                 task_unlock(current);
 105         }
 106 }
 107
 108 /* push / pop to root of obd store */
 109 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 110                struct lvfs_ucred *uc)
 111 {
 112         /* if there is underlaying dt_device then push_ctxt is not needed */
 113         if (new_ctx->dt != NULL)
 114                 return;
 115
 116         /* ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n"); */
 117         ASSERT_CTXT_MAGIC(new_ctx->magic);
 118         OBD_SET_CTXT_MAGIC(save);
 119
 120         save->fs = get_fs();
 121         LASSERT(d_count(cfs_fs_pwd(current->fs)));
 122         LASSERT(d_count(new_ctx->pwd));
 123         save->pwd = dget(cfs_fs_pwd(current->fs));
 124         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 125         save->luc.luc_umask = current_umask();
 126         save->ngroups = current_cred()->group_info->ngroups;
 127
 128         LASSERT(save->pwd);
 129         LASSERT(save->pwdmnt);
 130         LASSERT(new_ctx->pwd);
 131         LASSERT(new_ctx->pwdmnt);
 132
 133         if (uc) {
 134                 struct cred *cred;
 135                 save->luc.luc_uid = current_uid();
 136                 save->luc.luc_gid = current_gid();
 137                 save->luc.luc_fsuid = current_fsuid();
 138                 save->luc.luc_fsgid = current_fsgid();
 139                 save->luc.luc_cap = current_cap();
 140
 141                 cred = prepare_creds();
 142                 if (cred) {
 143                         cred->uid = uc->luc_uid;
 144                         cred->gid = uc->luc_gid;
 145                         cred->fsuid = uc->luc_fsuid;
 146                         cred->fsgid = uc->luc_fsgid;
 147                         cred->cap_effective = uc->luc_cap;
 148                         commit_creds(cred);
 149                 }
 150
 151                 push_group_info(save,
 152                                 uc->luc_ginfo ?:
 153                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 154                                                    NULL);
 155         }
 156         current->fs->umask = 0; /* umask already applied on client */
 157         set_fs(new_ctx->fs);
 158         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 159 }
 160 EXPORT_SYMBOL(push_ctxt);
 161
 162 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 163               struct lvfs_ucred *uc)
 164 {
 165         /* if there is underlaying dt_device then pop_ctxt is not needed */
 166         if (new_ctx->dt != NULL)
 167                 return;
 168
 169         ASSERT_CTXT_MAGIC(saved->magic);
 170         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 171
 172         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 173                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 174         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 175                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 176
 177         set_fs(saved->fs);
 178         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 179
 180         dput(saved->pwd);
 181         mntput(saved->pwdmnt);
 182         current->fs->umask = saved->luc.luc_umask;
 183         if (uc) {
 184                 struct cred *cred;
 185                 cred = prepare_creds();
 186                 if (cred) {
 187                         cred->uid = saved->luc.luc_uid;
 188                         cred->gid = saved->luc.luc_gid;
 189                         cred->fsuid = saved->luc.luc_fsuid;
 190                         cred->fsgid = saved->luc.luc_fsgid;
 191                         cred->cap_effective = saved->luc.luc_cap;
 192                         commit_creds(cred);
 193                 }
 194
 195                 pop_group_info(saved,
 196                                uc->luc_ginfo ?:
 197                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 198                                                   NULL);
 199         }
 200 }
 201 EXPORT_SYMBOL(pop_ctxt);
 202
 203 /* utility to rename a file */
 204 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 205                   char *oldname, char *newname)
 206 {
 207         struct dentry *dchild_old, *dchild_new;
 208         int err = 0;
 209
 210         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 211         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 212                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 213
 214         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 215         if (IS_ERR(dchild_old))
 216                 return PTR_ERR(dchild_old);
 217
 218         if (!dchild_old->d_inode)
 219                 GOTO(put_old, err = -ENOENT);
 220
 221         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 222         if (IS_ERR(dchild_new))
 223                 GOTO(put_old, err = PTR_ERR(dchild_new));
 224
 225         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 226                             dir->d_inode, dchild_new, mnt, NULL);
 227
 228         dput(dchild_new);
 229 put_old:
 230         dput(dchild_old);
 231         return err;
 232 }
 233 EXPORT_SYMBOL(lustre_rename);
 234
 235 /* Note: dput(dchild) will *not* be called if there is an error */
 236 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 237                              int flags)
 238 {
 239         struct path path = {
 240                 .dentry = de,
 241                 .mnt = ctxt->pwdmnt,
 242         };
 243         return dentry_open(&path, flags, current_cred());
 244 }
 245 EXPORT_SYMBOL(l_dentry_open);
 246
 247 #ifdef LPROCFS
 248 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 249                           struct lprocfs_counter_header *header,
 250                           enum lprocfs_stats_flags flags,
 251                           enum lprocfs_fields_flags field)
 252 {
 253         __s64 ret = 0;
 254
 255         if (lc == NULL || header == NULL)
 256                 return 0;
 257
 258         switch (field) {
 259         case LPROCFS_FIELDS_FLAGS_CONFIG:
 260                 ret = header->lc_config;
 261                 break;
 262         case LPROCFS_FIELDS_FLAGS_SUM:
 263                 ret = lc->lc_sum;
 264                 if ((flags & LPROCFS_STATS_FLAG_IRQ_SAFE) != 0)
 265                         ret += lc->lc_sum_irq;
 266                 break;
 267         case LPROCFS_FIELDS_FLAGS_MIN:
 268                 ret = lc->lc_min;
 269                 break;
 270         case LPROCFS_FIELDS_FLAGS_MAX:
 271                 ret = lc->lc_max;
 272                 break;
 273         case LPROCFS_FIELDS_FLAGS_AVG:
 274                 ret = (lc->lc_max - lc->lc_min) / 2;
 275                 break;
 276         case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 277                 ret = lc->lc_sumsquare;
 278                 break;
 279         case LPROCFS_FIELDS_FLAGS_COUNT:
 280                 ret = lc->lc_count;
 281                 break;
 282         default:
 283                 break;
 284         }
 285
 286         return ret;
 287 }
 288 EXPORT_SYMBOL(lprocfs_read_helper);
 289 #endif /* LPROCFS */
 290
 291 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 292 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 293 MODULE_LICENSE("GPL");