lustre/obdclass/simple.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002, 2003 Cluster File Systems, Inc.
   5  *  Author: Peter Braam <braam@clusterfs.com>
   6  *  Aurhot: Andreas Dilger <adilger@clusterfs.com>
   7  *
   8  *   This file is part of Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #define EXPORT_SYMTAB
  25
  26 #include <linux/version.h>
  27 #include <linux/fs.h>
  28 #include <asm/unistd.h>
  29
  30 #define DEBUG_SUBSYSTEM S_FILTER
  31
  32 #include <linux/obd.h>
  33 #include <linux/lustre_lib.h>
  34
  35 /* Debugging check only needed during development */
  36 #ifdef OBD_CTXT_DEBUG
  37 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  38 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERT(!segment_eq(get_fs(), get_ds()))
  39 # define ASSERT_KERNEL_CTXT(msg) LASSERT(segment_eq(get_fs(), get_ds()))
  40 #else
  41 # define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  42 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  43 # define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  44 #endif
  45
  46 /* push / pop to root of obd store */
  47 void push_ctxt(struct obd_run_ctxt *save, struct obd_run_ctxt *new_ctx,
  48                struct obd_ucred *uc)
  49 {
  50         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
  51         ASSERT_CTXT_MAGIC(new_ctx->magic);
  52         OBD_SET_CTXT_MAGIC(save);
  53
  54         /*
  55         CDEBUG(D_INFO,
  56                "= push %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
  57                save, current, current->fs, current->fs->pwd,
  58                atomic_read(&current->fs->pwd->d_count),
  59                atomic_read(&current->fs->pwd->d_inode->i_count),
  60                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
  61                current->fs->pwdmnt,
  62                atomic_read(&current->fs->pwdmnt->mnt_count));
  63         */
  64
  65         save->fs = get_fs();
  66         LASSERT(atomic_read(&current->fs->pwd->d_count));
  67         LASSERT(atomic_read(&new_ctx->pwd->d_count));
  68         save->pwd = dget(current->fs->pwd);
  69         save->pwdmnt = mntget(current->fs->pwdmnt);
  70         save->ngroups = current->ngroups;
  71
  72         LASSERT(save->pwd);
  73         LASSERT(save->pwdmnt);
  74         LASSERT(new_ctx->pwd);
  75         LASSERT(new_ctx->pwdmnt);
  76
  77         if (uc) {
  78                 save->ouc.ouc_fsuid = current->fsuid;
  79                 save->ouc.ouc_fsgid = current->fsgid;
  80                 save->ouc.ouc_cap = current->cap_effective;
  81                 save->ouc.ouc_suppgid1 = current->groups[0];
  82                 save->ouc.ouc_suppgid2 = current->groups[1];
  83
  84                 current->fsuid = uc->ouc_fsuid;
  85                 current->fsgid = uc->ouc_fsgid;
  86                 current->cap_effective = uc->ouc_cap;
  87                 current->ngroups = 0;
  88
  89                 if (uc->ouc_suppgid1 != -1)
  90                         current->groups[current->ngroups++] = uc->ouc_suppgid1;
  91                 if (uc->ouc_suppgid2 != -1)
  92                         current->groups[current->ngroups++] = uc->ouc_suppgid2;
  93         }
  94         set_fs(new_ctx->fs);
  95         set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
  96
  97         /*
  98         CDEBUG(D_INFO,
  99                "= push %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 100                new_ctx, current, current->fs, current->fs->pwd,
 101                atomic_read(&current->fs->pwd->d_count),
 102                atomic_read(&current->fs->pwd->d_inode->i_count),
 103                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 104                current->fs->pwdmnt,
 105                atomic_read(&current->fs->pwdmnt->mnt_count));
 106         */
 107 }
 108 EXPORT_SYMBOL(push_ctxt);
 109
 110 void pop_ctxt(struct obd_run_ctxt *saved, struct obd_run_ctxt *new_ctx,
 111               struct obd_ucred *uc)
 112 {
 113         //printk("pc0");
 114         ASSERT_CTXT_MAGIC(saved->magic);
 115         //printk("pc1");
 116         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 117
 118         /*
 119         CDEBUG(D_INFO,
 120                " = pop  %p==%p = cur %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 121                new_ctx, current, current->fs, current->fs->pwd,
 122                atomic_read(&current->fs->pwd->d_count),
 123                atomic_read(&current->fs->pwd->d_inode->i_count),
 124                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 125                current->fs->pwdmnt,
 126                atomic_read(&current->fs->pwdmnt->mnt_count));
 127         */
 128
 129         LASSERT(current->fs->pwd == new_ctx->pwd);
 130         LASSERT(current->fs->pwdmnt == new_ctx->pwdmnt);
 131
 132         set_fs(saved->fs);
 133         set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 134
 135         dput(saved->pwd);
 136         mntput(saved->pwdmnt);
 137         if (uc) {
 138                 current->fsuid = saved->ouc.ouc_fsuid;
 139                 current->fsgid = saved->ouc.ouc_fsgid;
 140                 current->cap_effective = saved->ouc.ouc_cap;
 141                 current->ngroups = saved->ngroups;
 142                 current->groups[0] = saved->ouc.ouc_suppgid1;
 143                 current->groups[1] = saved->ouc.ouc_suppgid2;
 144         }
 145
 146         /*
 147         CDEBUG(D_INFO,
 148                "= pop  %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 149                saved, current, current->fs, current->fs->pwd,
 150                atomic_read(&current->fs->pwd->d_count),
 151                atomic_read(&current->fs->pwd->d_inode->i_count),
 152                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 153                current->fs->pwdmnt,
 154                atomic_read(&current->fs->pwdmnt->mnt_count));
 155         */
 156 }
 157 EXPORT_SYMBOL(pop_ctxt);
 158
 159 /* utility to make a file */
 160 struct dentry *simple_mknod(struct dentry *dir, char *name, int mode)
 161 {
 162         struct dentry *dchild;
 163         int err = 0;
 164         ENTRY;
 165
 166         ASSERT_KERNEL_CTXT("kernel doing mknod outside kernel context\n");
 167         CDEBUG(D_INODE, "creating file %*s\n", (int)strlen(name), name);
 168
 169         dchild = ll_lookup_one_len(name, dir, strlen(name));
 170         if (IS_ERR(dchild))
 171                 GOTO(out_up, dchild);
 172
 173         if (dchild->d_inode) {
 174                 if (!S_ISREG(dchild->d_inode->i_mode))
 175                         GOTO(out_err, err = -EEXIST);
 176
 177                 GOTO(out_up, dchild);
 178         }
 179
 180         err = vfs_create(dir->d_inode, dchild, (mode & ~S_IFMT) | S_IFREG);
 181         if (err)
 182                 GOTO(out_err, err);
 183
 184         RETURN(dchild);
 185
 186 out_err:
 187         dput(dchild);
 188         dchild = ERR_PTR(err);
 189 out_up:
 190         return dchild;
 191 }
 192 EXPORT_SYMBOL(simple_mknod);
 193
 194 /* utility to make a directory */
 195 struct dentry *simple_mkdir(struct dentry *dir, char *name, int mode)
 196 {
 197         struct dentry *dchild;
 198         int err = 0;
 199         ENTRY;
 200
 201         ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
 202         CDEBUG(D_INODE, "creating directory %*s\n", (int)strlen(name), name);
 203         dchild = ll_lookup_one_len(name, dir, strlen(name));
 204         if (IS_ERR(dchild))
 205                 GOTO(out_up, dchild);
 206
 207         if (dchild->d_inode) {
 208                 if (!S_ISDIR(dchild->d_inode->i_mode))
 209                         GOTO(out_err, err = -ENOTDIR);
 210
 211                 GOTO(out_up, dchild);
 212         }
 213
 214         err = vfs_mkdir(dir->d_inode, dchild, mode);
 215         if (err)
 216                 GOTO(out_err, err);
 217
 218         RETURN(dchild);
 219
 220 out_err:
 221         dput(dchild);
 222         dchild = ERR_PTR(err);
 223 out_up:
 224         return dchild;
 225 }
 226 EXPORT_SYMBOL(simple_mkdir);
 227
 228 /*
 229  * Read a file from within kernel context.  Prior to calling this
 230  * function we should already have done a push_ctxt().
 231  */
 232 int lustre_fread(struct file *file, void *buf, int len, loff_t *off)
 233 {
 234         ASSERT_KERNEL_CTXT("kernel doing read outside kernel context\n");
 235         if (!file || !file->f_op || !file->f_op->read || !off)
 236                 RETURN(-ENOSYS);
 237
 238         return file->f_op->read(file, buf, len, off);
 239 }
 240 EXPORT_SYMBOL(lustre_fread);
 241
 242 /*
 243  * Write a file from within kernel context.  Prior to calling this
 244  * function we should already have done a push_ctxt().
 245  */
 246 int lustre_fwrite(struct file *file, const void *buf, int len, loff_t *off)
 247 {
 248         ENTRY;
 249         ASSERT_KERNEL_CTXT("kernel doing write outside kernel context\n");
 250         if (!file)
 251                 RETURN(-ENOENT);
 252         if (!file->f_op)
 253                 RETURN(-ENOSYS);
 254         if (!off)
 255                 RETURN(-EINVAL);
 256
 257         if (!file->f_op->write)
 258                 RETURN(-EROFS);
 259
 260         RETURN(file->f_op->write(file, buf, len, off));
 261 }
 262 EXPORT_SYMBOL(lustre_fwrite);
 263
 264 /*
 265  * Sync a file from within kernel context.  Prior to calling this
 266  * function we should already have done a push_ctxt().
 267  */
 268 int lustre_fsync(struct file *file)
 269 {
 270         ENTRY;
 271         ASSERT_KERNEL_CTXT("kernel doing sync outside kernel context\n");
 272         if (!file || !file->f_op || !file->f_op->fsync)
 273                 RETURN(-ENOSYS);
 274
 275         RETURN(file->f_op->fsync(file, file->f_dentry, 0));
 276 }
 277 EXPORT_SYMBOL(lustre_fsync);