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/version.h>
  44 #include <linux/fs.h>
  45 #include <asm/unistd.h>
  46 #include <linux/slab.h>
  47 #include <linux/pagemap.h>
  48 #include <linux/quotaops.h>
  49 #include <linux/version.h>
  50 #include <libcfs/libcfs.h>
  51 #include <lustre_fsfilt.h>
  52 #include <obd.h>
  53 #include <linux/module.h>
  54 #include <linux/init.h>
  55 #include <linux/lustre_compat25.h>
  56 #include <lvfs.h>
  57
  58 #include <obd.h>
  59 #include <lustre_lib.h>
  60
  61 struct lprocfs_stats *obd_memory = NULL;
  62 EXPORT_SYMBOL(obd_memory);
  63 /* refine later and change to seqlock or simlar from libcfs */
  64
  65 /* Debugging check only needed during development */
  66 #ifdef OBD_CTXT_DEBUG
  67 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  68 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  69                                               msg)
  70 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  71 #else
  72 # define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  73 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  74 # define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  75 #endif
  76
  77 static void push_group_info(struct lvfs_run_ctxt *save,
  78                             struct group_info *ginfo)
  79 {
  80         if (!ginfo) {
  81                 save->ngroups = current_ngroups;
  82                 current_ngroups = 0;
  83         } else {
  84                 struct cred *cred;
  85                 task_lock(current);
  86                 save->group_info = current_cred()->group_info;
  87                 if ((cred = prepare_creds())) {
  88                         cred->group_info = ginfo;
  89                         commit_creds(cred);
  90                 }
  91                 task_unlock(current);
  92         }
  93 }
  94
  95 static void pop_group_info(struct lvfs_run_ctxt *save,
  96                            struct group_info *ginfo)
  97 {
  98         if (!ginfo) {
  99                 current_ngroups = save->ngroups;
 100         } else {
 101                 struct cred *cred;
 102                 task_lock(current);
 103                 if ((cred = prepare_creds())) {
 104                         cred->group_info = save->group_info;
 105                         commit_creds(cred);
 106                 }
 107                 task_unlock(current);
 108         }
 109 }
 110
 111 /* push / pop to root of obd store */
 112 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 113                struct lvfs_ucred *uc)
 114 {
 115         /* if there is underlaying dt_device then push_ctxt is not needed */
 116         if (new_ctx->dt != NULL)
 117                 return;
 118
 119         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
 120         ASSERT_CTXT_MAGIC(new_ctx->magic);
 121         OBD_SET_CTXT_MAGIC(save);
 122
 123         save->fs = get_fs();
 124         LASSERT(d_refcount(cfs_fs_pwd(current->fs)));
 125         LASSERT(d_refcount(new_ctx->pwd));
 126         save->pwd = dget(cfs_fs_pwd(current->fs));
 127         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 128         save->luc.luc_umask = cfs_curproc_umask();
 129         save->ngroups = current_cred()->group_info->ngroups;
 130
 131         LASSERT(save->pwd);
 132         LASSERT(save->pwdmnt);
 133         LASSERT(new_ctx->pwd);
 134         LASSERT(new_ctx->pwdmnt);
 135
 136         if (uc) {
 137                 struct cred *cred;
 138                 save->luc.luc_uid = current_uid();
 139                 save->luc.luc_gid = current_gid();
 140                 save->luc.luc_fsuid = current_fsuid();
 141                 save->luc.luc_fsgid = current_fsgid();
 142                 save->luc.luc_cap = current_cap();
 143
 144                 if ((cred = prepare_creds())) {
 145                         cred->uid = uc->luc_uid;
 146                         cred->gid = uc->luc_gid;
 147                         cred->fsuid = uc->luc_fsuid;
 148                         cred->fsgid = uc->luc_fsgid;
 149                         cred->cap_effective = uc->luc_cap;
 150                         commit_creds(cred);
 151                 }
 152
 153                 push_group_info(save,
 154                                 uc->luc_ginfo ?:
 155                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 156                                                    NULL);
 157         }
 158         current->fs->umask = 0; /* umask already applied on client */
 159         set_fs(new_ctx->fs);
 160         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 161 }
 162 EXPORT_SYMBOL(push_ctxt);
 163
 164 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 165               struct lvfs_ucred *uc)
 166 {
 167         /* if there is underlaying dt_device then pop_ctxt is not needed */
 168         if (new_ctx->dt != NULL)
 169                 return;
 170
 171         ASSERT_CTXT_MAGIC(saved->magic);
 172         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 173
 174         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 175                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 176         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 177                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 178
 179         set_fs(saved->fs);
 180         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 181
 182         dput(saved->pwd);
 183         mntput(saved->pwdmnt);
 184         current->fs->umask = saved->luc.luc_umask;
 185         if (uc) {
 186                 struct cred *cred;
 187                 if ((cred = prepare_creds())) {
 188                         cred->uid = saved->luc.luc_uid;
 189                         cred->gid = saved->luc.luc_gid;
 190                         cred->fsuid = saved->luc.luc_fsuid;
 191                         cred->fsgid = saved->luc.luc_fsgid;
 192                         cred->cap_effective = saved->luc.luc_cap;
 193                         commit_creds(cred);
 194                 }
 195
 196                 pop_group_info(saved,
 197                                uc->luc_ginfo ?:
 198                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 199                                                   NULL);
 200         }
 201 }
 202 EXPORT_SYMBOL(pop_ctxt);
 203
 204 /* utility to rename a file */
 205 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 206                   char *oldname, char *newname)
 207 {
 208         struct dentry *dchild_old, *dchild_new;
 209         int err = 0;
 210         ENTRY;
 211
 212         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 213         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 214                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 215
 216         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 217         if (IS_ERR(dchild_old))
 218                 RETURN(PTR_ERR(dchild_old));
 219
 220         if (!dchild_old->d_inode)
 221                 GOTO(put_old, err = -ENOENT);
 222
 223         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 224         if (IS_ERR(dchild_new))
 225                 GOTO(put_old, err = PTR_ERR(dchild_new));
 226
 227         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 228                             dir->d_inode, dchild_new, mnt);
 229
 230         dput(dchild_new);
 231 put_old:
 232         dput(dchild_old);
 233         RETURN(err);
 234 }
 235 EXPORT_SYMBOL(lustre_rename);
 236
 237 /* Note: dput(dchild) will be called if there is an error */
 238 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 239                              int flags)
 240 {
 241         mntget(ctxt->pwdmnt);
 242         return ll_dentry_open(de, ctxt->pwdmnt, flags, current_cred());
 243 }
 244 EXPORT_SYMBOL(l_dentry_open);
 245
 246 #ifdef LPROCFS
 247 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 248                           struct lprocfs_counter_header *header,
 249                           enum lprocfs_stats_flags flags,
 250                           enum lprocfs_fields_flags field)
 251 {
 252         __s64 ret = 0;
 253
 254         if (lc == NULL || header == NULL)
 255                 RETURN(0);
 256
 257         switch (field) {
 258                 case LPROCFS_FIELDS_FLAGS_CONFIG:
 259                         ret = header->lc_config;
 260                         break;
 261                 case LPROCFS_FIELDS_FLAGS_SUM:
 262                         ret = lc->lc_sum;
 263                         if ((flags & LPROCFS_STATS_FLAG_IRQ_SAFE) != 0)
 264                                 ret += lc->lc_sum_irq;
 265                         break;
 266                 case LPROCFS_FIELDS_FLAGS_MIN:
 267                         ret = lc->lc_min;
 268                         break;
 269                 case LPROCFS_FIELDS_FLAGS_MAX:
 270                         ret = lc->lc_max;
 271                         break;
 272                 case LPROCFS_FIELDS_FLAGS_AVG:
 273                         ret = (lc->lc_max - lc->lc_min) / 2;
 274                         break;
 275                 case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 276                         ret = lc->lc_sumsquare;
 277                         break;
 278                 case LPROCFS_FIELDS_FLAGS_COUNT:
 279                         ret = lc->lc_count;
 280                         break;
 281                 default:
 282                         break;
 283         };
 284
 285         RETURN(ret);
 286 }
 287 EXPORT_SYMBOL(lprocfs_read_helper);
 288 #endif /* LPROCFS */
 289
 290 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 291 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 292 MODULE_LICENSE("GPL");