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 #ifndef EXPORT_SYMTAB
  25 # define EXPORT_SYMTAB
  26 #endif
  27
  28 #include <linux/version.h>
  29 #include <linux/fs.h>
  30 #include <asm/unistd.h>
  31
  32 #define DEBUG_SUBSYSTEM S_FILTER
  33
  34 #include <linux/obd.h>
  35 #include <linux/lustre_lib.h>
  36 #include <linux/lustre_compat25.h>
  37
  38 /* Debugging check only needed during development */
  39 #ifdef OBD_CTXT_DEBUG
  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 lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
  51                struct lvfs_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         save->ngroups = current->ngroups;
  74
  75         LASSERT(save->pwd);
  76         LASSERT(save->pwdmnt);
  77         LASSERT(new_ctx->pwd);
  78         LASSERT(new_ctx->pwdmnt);
  79
  80         if (uc) {
  81                 save->luc.luc_fsuid = current->fsuid;
  82                 save->luc.luc_fsgid = current->fsgid;
  83                 save->luc.luc_cap = current->cap_effective;
  84                 save->luc.luc_suppgid1 = current->groups[0];
  85                 save->luc.luc_suppgid2 = current->groups[1];
  86
  87                 current->fsuid = uc->luc_fsuid;
  88                 current->fsgid = uc->luc_fsgid;
  89                 current->cap_effective = uc->luc_cap;
  90                 current->ngroups = 0;
  91
  92                 if (uc->luc_suppgid1 != -1)
  93                         current->groups[current->ngroups++] = uc->luc_suppgid1;
  94                 if (uc->luc_suppgid2 != -1)
  95                         current->groups[current->ngroups++] = uc->luc_suppgid2;
  96         }
  97         set_fs(new_ctx->fs);
  98         set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
  99
 100         /*
 101         CDEBUG(D_INFO,
 102                "= push %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 103                new_ctx, current, current->fs, current->fs->pwd,
 104                atomic_read(&current->fs->pwd->d_count),
 105                atomic_read(&current->fs->pwd->d_inode->i_count),
 106                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 107                current->fs->pwdmnt,
 108                atomic_read(&current->fs->pwdmnt->mnt_count));
 109         */
 110 }
 111 EXPORT_SYMBOL(push_ctxt);
 112
 113 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 114               struct lvfs_ucred *uc)
 115 {
 116         //printk("pc0");
 117         ASSERT_CTXT_MAGIC(saved->magic);
 118         //printk("pc1");
 119         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 120
 121         /*
 122         CDEBUG(D_INFO,
 123                " = pop  %p==%p = cur %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 124                new_ctx, current, current->fs, current->fs->pwd,
 125                atomic_read(&current->fs->pwd->d_count),
 126                atomic_read(&current->fs->pwd->d_inode->i_count),
 127                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 128                current->fs->pwdmnt,
 129                atomic_read(&current->fs->pwdmnt->mnt_count));
 130         */
 131
 132         LASSERT(current->fs->pwd == new_ctx->pwd);
 133         LASSERT(current->fs->pwdmnt == new_ctx->pwdmnt);
 134
 135         set_fs(saved->fs);
 136         set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 137
 138         dput(saved->pwd);
 139         mntput(saved->pwdmnt);
 140         if (uc) {
 141                 current->fsuid = saved->luc.luc_fsuid;
 142                 current->fsgid = saved->luc.luc_fsgid;
 143                 current->cap_effective = saved->luc.luc_cap;
 144                 current->ngroups = saved->ngroups;
 145                 current->groups[0] = saved->luc.luc_suppgid1;
 146                 current->groups[1] = saved->luc.luc_suppgid2;
 147         }
 148
 149         /*
 150         CDEBUG(D_INFO,
 151                "= pop  %p->%p = cur fs %p pwd %p:d%d:i%d (%*s), pwdmnt %p:%d\n",
 152                saved, current, current->fs, current->fs->pwd,
 153                atomic_read(&current->fs->pwd->d_count),
 154                atomic_read(&current->fs->pwd->d_inode->i_count),
 155                current->fs->pwd->d_name.len, current->fs->pwd->d_name.name,
 156                current->fs->pwdmnt,
 157                atomic_read(&current->fs->pwdmnt->mnt_count));
 158         */
 159 }
 160 EXPORT_SYMBOL(pop_ctxt);
 161
 162 /* utility to make a file */
 163 struct dentry *simple_mknod(struct dentry *dir, char *name, int mode)
 164 {
 165         struct dentry *dchild;
 166         int err = 0;
 167         ENTRY;
 168
 169         ASSERT_KERNEL_CTXT("kernel doing mknod outside kernel context\n");
 170         CDEBUG(D_INODE, "creating file %*s\n", (int)strlen(name), name);
 171
 172         dchild = ll_lookup_one_len(name, dir, strlen(name));
 173         if (IS_ERR(dchild))
 174                 GOTO(out_up, dchild);
 175
 176         if (dchild->d_inode) {
 177                 if (!S_ISREG(dchild->d_inode->i_mode))
 178                         GOTO(out_err, err = -EEXIST);
 179
 180                 GOTO(out_up, dchild);
 181         }
 182
 183         err = ll_vfs_create(dir->d_inode, dchild, (mode & ~S_IFMT) | S_IFREG, NULL);
 184         if (err)
 185                 GOTO(out_err, err);
 186
 187         RETURN(dchild);
 188
 189 out_err:
 190         dput(dchild);
 191         dchild = ERR_PTR(err);
 192 out_up:
 193         return dchild;
 194 }
 195 EXPORT_SYMBOL(simple_mknod);
 196
 197 /* utility to make a directory */
 198 struct dentry *simple_mkdir(struct dentry *dir, char *name, int mode)
 199 {
 200         struct dentry *dchild;
 201         int err = 0;
 202         ENTRY;
 203
 204         ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
 205         CDEBUG(D_INODE, "creating directory %*s\n", (int)strlen(name), name);
 206         dchild = ll_lookup_one_len(name, dir, strlen(name));
 207         if (IS_ERR(dchild))
 208                 GOTO(out_up, dchild);
 209
 210         if (dchild->d_inode) {
 211                 if (!S_ISDIR(dchild->d_inode->i_mode))
 212                         GOTO(out_err, err = -ENOTDIR);
 213
 214                 GOTO(out_up, dchild);
 215         }
 216
 217         err = vfs_mkdir(dir->d_inode, dchild, mode);
 218         if (err)
 219                 GOTO(out_err, err);
 220
 221         RETURN(dchild);
 222
 223 out_err:
 224         dput(dchild);
 225         dchild = ERR_PTR(err);
 226 out_up:
 227         return dchild;
 228 }
 229 EXPORT_SYMBOL(simple_mkdir);
 230
 231 /*
 232  * Read a file from within kernel context.  Prior to calling this
 233  * function we should already have done a push_ctxt().
 234  */
 235 int lustre_fread(struct file *file, void *buf, int len, loff_t *off)
 236 {
 237         ASSERT_KERNEL_CTXT("kernel doing read outside kernel context\n");
 238         if (!file || !file->f_op || !file->f_op->read || !off)
 239                 RETURN(-ENOSYS);
 240
 241         return file->f_op->read(file, buf, len, off);
 242 }
 243 EXPORT_SYMBOL(lustre_fread);
 244
 245 /*
 246  * Write a file from within kernel context.  Prior to calling this
 247  * function we should already have done a push_ctxt().
 248  */
 249 int lustre_fwrite(struct file *file, const void *buf, int len, loff_t *off)
 250 {
 251         ENTRY;
 252         ASSERT_KERNEL_CTXT("kernel doing write outside kernel context\n");
 253         if (!file)
 254                 RETURN(-ENOENT);
 255         if (!file->f_op)
 256                 RETURN(-ENOSYS);
 257         if (!off)
 258                 RETURN(-EINVAL);
 259
 260         if (!file->f_op->write)
 261                 RETURN(-EROFS);
 262
 263         RETURN(file->f_op->write(file, buf, len, off));
 264 }
 265 EXPORT_SYMBOL(lustre_fwrite);
 266