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 __u64 obd_max_pages = 0;
  62 __u64 obd_max_alloc = 0;
  63 struct lprocfs_stats *obd_memory = NULL;
  64 EXPORT_SYMBOL(obd_memory);
  65 DEFINE_SPINLOCK(obd_updatemax_lock);
  66 /* refine later and change to seqlock or simlar from libcfs */
  67
  68 /* Debugging check only needed during development */
  69 #ifdef OBD_CTXT_DEBUG
  70 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  71 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  72                                               msg)
  73 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  74 #else
  75 # define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  76 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  77 # define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  78 #endif
  79
  80 static void push_group_info(struct lvfs_run_ctxt *save,
  81                             struct group_info *ginfo)
  82 {
  83         if (!ginfo) {
  84                 save->ngroups = current_ngroups;
  85                 current_ngroups = 0;
  86         } else {
  87                 struct cred *cred;
  88                 task_lock(current);
  89                 save->group_info = current_cred()->group_info;
  90                 if ((cred = prepare_creds())) {
  91                         cred->group_info = ginfo;
  92                         commit_creds(cred);
  93                 }
  94                 task_unlock(current);
  95         }
  96 }
  97
  98 static void pop_group_info(struct lvfs_run_ctxt *save,
  99                            struct group_info *ginfo)
 100 {
 101         if (!ginfo) {
 102                 current_ngroups = save->ngroups;
 103         } else {
 104                 struct cred *cred;
 105                 task_lock(current);
 106                 if ((cred = prepare_creds())) {
 107                         cred->group_info = save->group_info;
 108                         commit_creds(cred);
 109                 }
 110                 task_unlock(current);
 111         }
 112 }
 113
 114 /* push / pop to root of obd store */
 115 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 116                struct lvfs_ucred *uc)
 117 {
 118         /* if there is underlaying dt_device then push_ctxt is not needed */
 119         if (new_ctx->dt != NULL)
 120                 return;
 121
 122         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
 123         ASSERT_CTXT_MAGIC(new_ctx->magic);
 124         OBD_SET_CTXT_MAGIC(save);
 125
 126         save->fs = get_fs();
 127         LASSERT(d_refcount(cfs_fs_pwd(current->fs)));
 128         LASSERT(d_refcount(new_ctx->pwd));
 129         save->pwd = dget(cfs_fs_pwd(current->fs));
 130         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 131         save->luc.luc_umask = cfs_curproc_umask();
 132         save->ngroups = current_cred()->group_info->ngroups;
 133
 134         LASSERT(save->pwd);
 135         LASSERT(save->pwdmnt);
 136         LASSERT(new_ctx->pwd);
 137         LASSERT(new_ctx->pwdmnt);
 138
 139         if (uc) {
 140                 struct cred *cred;
 141                 save->luc.luc_uid = current_uid();
 142                 save->luc.luc_gid = current_gid();
 143                 save->luc.luc_fsuid = current_fsuid();
 144                 save->luc.luc_fsgid = current_fsgid();
 145                 save->luc.luc_cap = current_cap();
 146
 147                 if ((cred = prepare_creds())) {
 148                         cred->uid = uc->luc_uid;
 149                         cred->gid = uc->luc_gid;
 150                         cred->fsuid = uc->luc_fsuid;
 151                         cred->fsgid = uc->luc_fsgid;
 152                         cred->cap_effective = uc->luc_cap;
 153                         commit_creds(cred);
 154                 }
 155
 156                 push_group_info(save,
 157                                 uc->luc_ginfo ?:
 158                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 159                                                    NULL);
 160         }
 161         current->fs->umask = 0; /* umask already applied on client */
 162         set_fs(new_ctx->fs);
 163         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 164 }
 165 EXPORT_SYMBOL(push_ctxt);
 166
 167 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 168               struct lvfs_ucred *uc)
 169 {
 170         /* if there is underlaying dt_device then pop_ctxt is not needed */
 171         if (new_ctx->dt != NULL)
 172                 return;
 173
 174         ASSERT_CTXT_MAGIC(saved->magic);
 175         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 176
 177         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 178                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 179         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 180                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 181
 182         set_fs(saved->fs);
 183         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 184
 185         dput(saved->pwd);
 186         mntput(saved->pwdmnt);
 187         current->fs->umask = saved->luc.luc_umask;
 188         if (uc) {
 189                 struct cred *cred;
 190                 if ((cred = prepare_creds())) {
 191                         cred->uid = saved->luc.luc_uid;
 192                         cred->gid = saved->luc.luc_gid;
 193                         cred->fsuid = saved->luc.luc_fsuid;
 194                         cred->fsgid = saved->luc.luc_fsgid;
 195                         cred->cap_effective = saved->luc.luc_cap;
 196                         commit_creds(cred);
 197                 }
 198
 199                 pop_group_info(saved,
 200                                uc->luc_ginfo ?:
 201                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 202                                                   NULL);
 203         }
 204 }
 205 EXPORT_SYMBOL(pop_ctxt);
 206
 207 /* utility to rename a file */
 208 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 209                   char *oldname, char *newname)
 210 {
 211         struct dentry *dchild_old, *dchild_new;
 212         int err = 0;
 213         ENTRY;
 214
 215         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 216         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 217                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 218
 219         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 220         if (IS_ERR(dchild_old))
 221                 RETURN(PTR_ERR(dchild_old));
 222
 223         if (!dchild_old->d_inode)
 224                 GOTO(put_old, err = -ENOENT);
 225
 226         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 227         if (IS_ERR(dchild_new))
 228                 GOTO(put_old, err = PTR_ERR(dchild_new));
 229
 230         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 231                             dir->d_inode, dchild_new, mnt);
 232
 233         dput(dchild_new);
 234 put_old:
 235         dput(dchild_old);
 236         RETURN(err);
 237 }
 238 EXPORT_SYMBOL(lustre_rename);
 239
 240 /* Note: dput(dchild) will be called if there is an error */
 241 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 242                              int flags)
 243 {
 244         mntget(ctxt->pwdmnt);
 245         return ll_dentry_open(de, ctxt->pwdmnt, flags, current_cred());
 246 }
 247 EXPORT_SYMBOL(l_dentry_open);
 248
 249 void obd_update_maxusage()
 250 {
 251         __u64 max1, max2;
 252
 253         max1 = obd_pages_sum();
 254         max2 = obd_memory_sum();
 255
 256         spin_lock(&obd_updatemax_lock);
 257         if (max1 > obd_max_pages)
 258                 obd_max_pages = max1;
 259         if (max2 > obd_max_alloc)
 260                 obd_max_alloc = max2;
 261         spin_unlock(&obd_updatemax_lock);
 262
 263 }
 264 EXPORT_SYMBOL(obd_update_maxusage);
 265
 266 __u64 obd_memory_max(void)
 267 {
 268         __u64 ret;
 269
 270         spin_lock(&obd_updatemax_lock);
 271         ret = obd_max_alloc;
 272         spin_unlock(&obd_updatemax_lock);
 273
 274         return ret;
 275 }
 276 EXPORT_SYMBOL(obd_memory_max);
 277
 278 __u64 obd_pages_max(void)
 279 {
 280         __u64 ret;
 281
 282         spin_lock(&obd_updatemax_lock);
 283         ret = obd_max_pages;
 284         spin_unlock(&obd_updatemax_lock);
 285
 286         return ret;
 287 }
 288 EXPORT_SYMBOL(obd_pages_max);
 289
 290 #ifdef LPROCFS
 291 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 292                           struct lprocfs_counter_header *header,
 293                           enum lprocfs_stats_flags flags,
 294                           enum lprocfs_fields_flags field)
 295 {
 296         __s64 ret = 0;
 297
 298         if (lc == NULL || header == NULL)
 299                 RETURN(0);
 300
 301         switch (field) {
 302                 case LPROCFS_FIELDS_FLAGS_CONFIG:
 303                         ret = header->lc_config;
 304                         break;
 305                 case LPROCFS_FIELDS_FLAGS_SUM:
 306                         ret = lc->lc_sum;
 307                         if ((flags & LPROCFS_STATS_FLAG_IRQ_SAFE) != 0)
 308                                 ret += lc->lc_sum_irq;
 309                         break;
 310                 case LPROCFS_FIELDS_FLAGS_MIN:
 311                         ret = lc->lc_min;
 312                         break;
 313                 case LPROCFS_FIELDS_FLAGS_MAX:
 314                         ret = lc->lc_max;
 315                         break;
 316                 case LPROCFS_FIELDS_FLAGS_AVG:
 317                         ret = (lc->lc_max - lc->lc_min) / 2;
 318                         break;
 319                 case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 320                         ret = lc->lc_sumsquare;
 321                         break;
 322                 case LPROCFS_FIELDS_FLAGS_COUNT:
 323                         ret = lc->lc_count;
 324                         break;
 325                 default:
 326                         break;
 327         };
 328
 329         RETURN(ret);
 330 }
 331 EXPORT_SYMBOL(lprocfs_read_helper);
 332 #endif /* LPROCFS */
 333
 334 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 335 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 336 MODULE_LICENSE("GPL");