lustre/lib/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_support.h>
  33 #include <linux/obd.h>
  34 #include <linux/lustre_mds.h>
  35 #include <linux/lustre_lib.h>
  36 #include <linux/lustre_net.h>
  37
  38 #ifdef OBD_CTXT_DEBUG
  39 /* Debugging check only needed during development */
  40 #define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  41 #define ASSERT_NOT_KERNEL_CTXT(msg) LASSERT(!segment_eq(get_fs(), get_ds()))
  42 #define ASSERT_KERNEL_CTXT(msg) LASSERT(segment_eq(get_fs(), get_ds()))
  43 #else
  44 #define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  45 #define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  46 #define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  47 #endif
  48
  49 /* push / pop to root of obd store */
  50 void push_ctxt(struct obd_run_ctxt *save, struct obd_run_ctxt *new_ctx,
  51                struct obd_ucred *uc)
  52 {
  53         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
  54         ASSERT_CTXT_MAGIC(new_ctx->magic);
  55         OBD_SET_CTXT_MAGIC(save);
  56
  57         /*
  58         CDEBUG(D_INFO,
  59                "= push %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
  60                save, current, current->fs, current->fs->pwd,
  61                atomic_read(&current->fs->pwd->d_count),
  62                atomic_read(&current->fs->pwd->d_inode->i_count),
  63                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
  64                current->fs->pwdmnt,
  65                atomic_read(&current->fs->pwdmnt->mnt_count));
  66         */
  67
  68         save->fs = get_fs();
  69         LASSERT(atomic_read(&current->fs->pwd->d_count));
  70         LASSERT(atomic_read(&new_ctx->pwd->d_count));
  71         save->pwd = dget(current->fs->pwd);
  72         save->pwdmnt = mntget(current->fs->pwdmnt);
  73
  74         LASSERT(save->pwd);
  75         LASSERT(save->pwdmnt);
  76         LASSERT(new_ctx->pwd);
  77         LASSERT(new_ctx->pwdmnt);
  78
  79         if (uc) {
  80                 save->fsuid = current->fsuid;
  81                 save->fsgid = current->fsgid;
  82                 save->cap = current->cap_effective;
  83
  84                 current->fsuid = uc->ouc_fsuid;
  85                 current->fsgid = uc->ouc_fsgid;
  86                 current->cap_effective = uc->ouc_cap;
  87                 if (uc->ouc_suppgid1 != -1)
  88                         current->groups[current->ngroups++] = uc->ouc_suppgid1;
  89                 if (uc->ouc_suppgid2 != -1)
  90                         current->groups[current->ngroups++] = uc->ouc_suppgid2;
  91         }
  92         set_fs(new_ctx->fs);
  93         set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
  94
  95         /*
  96         CDEBUG(D_INFO,
  97                "= push %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
  98                new_ctx, current, current->fs, current->fs->pwd,
  99                atomic_read(&current->fs->pwd->d_count),
 100                atomic_read(&current->fs->pwd->d_inode->i_count),
 101                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 102                current->fs->pwdmnt,
 103                atomic_read(&current->fs->pwdmnt->mnt_count));
 104         */
 105 }
 106
 107 void pop_ctxt(struct obd_run_ctxt *saved, struct obd_run_ctxt *new_ctx,
 108               struct obd_ucred *uc)
 109 {
 110         //printk("pc0");
 111         ASSERT_CTXT_MAGIC(saved->magic);
 112         //printk("pc1");
 113         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 114
 115         /*
 116         CDEBUG(D_INFO,
 117                " = pop  %p==%p = cur %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 118                new_ctx, current, current->fs, current->fs->pwd,
 119                atomic_read(&current->fs->pwd->d_count),
 120                atomic_read(&current->fs->pwd->d_inode->i_count),
 121                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 122                current->fs->pwdmnt,
 123                atomic_read(&current->fs->pwdmnt->mnt_count));
 124         */
 125
 126         LASSERT(current->fs->pwd == new_ctx->pwd);
 127         LASSERT(current->fs->pwdmnt == new_ctx->pwdmnt);
 128
 129         set_fs(saved->fs);
 130         set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 131
 132         dput(saved->pwd);
 133         mntput(saved->pwdmnt);
 134         if (uc) {
 135                 current->fsuid = saved->fsuid;
 136                 current->fsgid = saved->fsgid;
 137                 current->cap_effective = saved->cap;
 138
 139                 if (uc->ouc_suppgid1 != -1)
 140                         current->ngroups--;
 141                 if (uc->ouc_suppgid2 != -1)
 142                         current->ngroups--;
 143         }
 144
 145         /*
 146         CDEBUG(D_INFO,
 147                "= pop  %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 148                saved, current, current->fs, current->fs->pwd,
 149                atomic_read(&current->fs->pwd->d_count),
 150                atomic_read(&current->fs->pwd->d_inode->i_count),
 151                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 152                current->fs->pwdmnt,
 153                atomic_read(&current->fs->pwdmnt->mnt_count));
 154         */
 155 }
 156
 157 /* utility to make a file */
 158 struct dentry *simple_mknod(struct dentry *dir, char *name, int mode)
 159 {
 160         struct dentry *dchild;
 161         int err = 0;
 162         ENTRY;
 163
 164         ASSERT_KERNEL_CTXT("kernel doing mknod outside kernel context\n");
 165         CDEBUG(D_INODE, "creating file %*s\n", (int)strlen(name), name);
 166
 167         dchild = lookup_one_len(name, dir, strlen(name));
 168         if (IS_ERR(dchild))
 169                 GOTO(out_up, dchild);
 170
 171         if (dchild->d_inode) {
 172                 if ((dchild->d_inode->i_mode & S_IFMT) != S_IFREG)
 173                         GOTO(out_err, err = -EEXIST);
 174
 175                 GOTO(out_up, dchild);
 176         }
 177
 178         err = vfs_create(dir->d_inode, dchild, (mode & ~S_IFMT) | S_IFREG);
 179         if (err)
 180                 GOTO(out_err, err);
 181
 182         RETURN(dchild);
 183
 184 out_err:
 185         dput(dchild);
 186         dchild = ERR_PTR(err);
 187 out_up:
 188         return dchild;
 189 }
 190
 191 /* utility to make a directory */
 192 struct dentry *simple_mkdir(struct dentry *dir, char *name, int mode)
 193 {
 194         struct dentry *dchild;
 195         int err = 0;
 196         ENTRY;
 197
 198         ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
 199         CDEBUG(D_INODE, "creating directory %*s\n", (int)strlen(name), name);
 200         dchild = lookup_one_len(name, dir, strlen(name));
 201         if (IS_ERR(dchild))
 202                 GOTO(out_up, dchild);
 203
 204         if (dchild->d_inode) {
 205                 if (!S_ISDIR(dchild->d_inode->i_mode))
 206                         GOTO(out_err, err = -ENOTDIR);
 207
 208                 GOTO(out_up, dchild);
 209         }
 210
 211         err = vfs_mkdir(dir->d_inode, dchild, mode);
 212         if (err)
 213                 GOTO(out_err, err);
 214
 215         RETURN(dchild);
 216
 217 out_err:
 218         dput(dchild);
 219         dchild = ERR_PTR(err);
 220 out_up:
 221         return dchild;
 222 }
 223
 224 /*
 225  * Read a file from within kernel context.  Prior to calling this
 226  * function we should already have done a push_ctxt().
 227  */
 228 int lustre_fread(struct file *file, char *str, int len, loff_t *off)
 229 {
 230         ASSERT_KERNEL_CTXT("kernel doing read outside kernel context\n");
 231         if (!file || !file->f_op || !file->f_op->read || !off)
 232                 RETURN(-ENOSYS);
 233
 234         return file->f_op->read(file, str, len, off);
 235 }
 236
 237 /*
 238  * Write a file from within kernel context.  Prior to calling this
 239  * function we should already have done a push_ctxt().
 240  */
 241 int lustre_fwrite(struct file *file, const char *str, int len, loff_t *off)
 242 {
 243         ENTRY;
 244         ASSERT_KERNEL_CTXT("kernel doing write outside kernel context\n");
 245         if (!file)
 246                 RETURN(-ENOENT);
 247         if (!file->f_op)
 248                 RETURN(-ENOSYS);
 249         if (!off)
 250                 RETURN(-EINVAL);
 251
 252         if (!file->f_op->write)
 253                 RETURN(-EROFS);
 254
 255         RETURN(file->f_op->write(file, str, len, off));
 256 }
 257
 258 /*
 259  * Sync a file from within kernel context.  Prior to calling this
 260  * function we should already have done a push_ctxt().
 261  */
 262 int lustre_fsync(struct file *file)
 263 {
 264         ENTRY;
 265         ASSERT_KERNEL_CTXT("kernel doing sync outside kernel context\n");
 266         if (!file || !file->f_op || !file->f_op->fsync)
 267                 RETURN(-ENOSYS);
 268
 269         RETURN(file->f_op->fsync(file, file->f_dentry, 0));
 270 }