linux/fs/coda/inode.c
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   1/*
   2 * Super block/filesystem wide operations
   3 *
   4 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and 
   5 * Michael Callahan <callahan@maths.ox.ac.uk> 
   6 * 
   7 * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
   8 * Copyright (C) Carnegie Mellon University
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/kernel.h>
  13#include <linux/mm.h>
  14#include <linux/string.h>
  15#include <linux/stat.h>
  16#include <linux/errno.h>
  17#include <linux/unistd.h>
  18#include <linux/mutex.h>
  19#include <linux/spinlock.h>
  20#include <linux/file.h>
  21#include <linux/vfs.h>
  22#include <linux/slab.h>
  23#include <linux/pid_namespace.h>
  24#include <linux/uaccess.h>
  25#include <linux/fs.h>
  26#include <linux/vmalloc.h>
  27
  28#include <linux/coda.h>
  29#include <linux/coda_psdev.h>
  30#include "coda_linux.h"
  31#include "coda_cache.h"
  32
  33#include "coda_int.h"
  34
  35/* VFS super_block ops */
  36static void coda_evict_inode(struct inode *);
  37static void coda_put_super(struct super_block *);
  38static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  39
  40static struct kmem_cache * coda_inode_cachep;
  41
  42static struct inode *coda_alloc_inode(struct super_block *sb)
  43{
  44        struct coda_inode_info *ei;
  45        ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
  46        if (!ei)
  47                return NULL;
  48        memset(&ei->c_fid, 0, sizeof(struct CodaFid));
  49        ei->c_flags = 0;
  50        ei->c_uid = GLOBAL_ROOT_UID;
  51        ei->c_cached_perm = 0;
  52        spin_lock_init(&ei->c_lock);
  53        return &ei->vfs_inode;
  54}
  55
  56static void coda_i_callback(struct rcu_head *head)
  57{
  58        struct inode *inode = container_of(head, struct inode, i_rcu);
  59        kmem_cache_free(coda_inode_cachep, ITOC(inode));
  60}
  61
  62static void coda_destroy_inode(struct inode *inode)
  63{
  64        call_rcu(&inode->i_rcu, coda_i_callback);
  65}
  66
  67static void init_once(void *foo)
  68{
  69        struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  70
  71        inode_init_once(&ei->vfs_inode);
  72}
  73
  74int __init coda_init_inodecache(void)
  75{
  76        coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  77                                sizeof(struct coda_inode_info),
  78                                0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  79                                init_once);
  80        if (coda_inode_cachep == NULL)
  81                return -ENOMEM;
  82        return 0;
  83}
  84
  85void coda_destroy_inodecache(void)
  86{
  87        /*
  88         * Make sure all delayed rcu free inodes are flushed before we
  89         * destroy cache.
  90         */
  91        rcu_barrier();
  92        kmem_cache_destroy(coda_inode_cachep);
  93}
  94
  95static int coda_remount(struct super_block *sb, int *flags, char *data)
  96{
  97        sync_filesystem(sb);
  98        *flags |= MS_NOATIME;
  99        return 0;
 100}
 101
 102/* exported operations */
 103static const struct super_operations coda_super_operations =
 104{
 105        .alloc_inode    = coda_alloc_inode,
 106        .destroy_inode  = coda_destroy_inode,
 107        .evict_inode    = coda_evict_inode,
 108        .put_super      = coda_put_super,
 109        .statfs         = coda_statfs,
 110        .remount_fs     = coda_remount,
 111};
 112
 113static int get_device_index(struct coda_mount_data *data)
 114{
 115        struct fd f;
 116        struct inode *inode;
 117        int idx;
 118
 119        if (data == NULL) {
 120                pr_warn("%s: Bad mount data\n", __func__);
 121                return -1;
 122        }
 123
 124        if (data->version != CODA_MOUNT_VERSION) {
 125                pr_warn("%s: Bad mount version\n", __func__);
 126                return -1;
 127        }
 128
 129        f = fdget(data->fd);
 130        if (!f.file)
 131                goto Ebadf;
 132        inode = file_inode(f.file);
 133        if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 134                fdput(f);
 135                goto Ebadf;
 136        }
 137
 138        idx = iminor(inode);
 139        fdput(f);
 140
 141        if (idx < 0 || idx >= MAX_CODADEVS) {
 142                pr_warn("%s: Bad minor number\n", __func__);
 143                return -1;
 144        }
 145
 146        return idx;
 147Ebadf:
 148        pr_warn("%s: Bad file\n", __func__);
 149        return -1;
 150}
 151
 152static int coda_fill_super(struct super_block *sb, void *data, int silent)
 153{
 154        struct inode *root = NULL;
 155        struct venus_comm *vc;
 156        struct CodaFid fid;
 157        int error;
 158        int idx;
 159
 160        if (task_active_pid_ns(current) != &init_pid_ns)
 161                return -EINVAL;
 162
 163        idx = get_device_index((struct coda_mount_data *) data);
 164
 165        /* Ignore errors in data, for backward compatibility */
 166        if(idx == -1)
 167                idx = 0;
 168        
 169        pr_info("%s: device index: %i\n", __func__,  idx);
 170
 171        vc = &coda_comms[idx];
 172        mutex_lock(&vc->vc_mutex);
 173
 174        if (!vc->vc_inuse) {
 175                pr_warn("%s: No pseudo device\n", __func__);
 176                error = -EINVAL;
 177                goto unlock_out;
 178        }
 179
 180        if (vc->vc_sb) {
 181                pr_warn("%s: Device already mounted\n", __func__);
 182                error = -EBUSY;
 183                goto unlock_out;
 184        }
 185
 186        error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 187        if (error)
 188                goto unlock_out;
 189
 190        vc->vc_sb = sb;
 191        mutex_unlock(&vc->vc_mutex);
 192
 193        sb->s_fs_info = vc;
 194        sb->s_flags |= MS_NOATIME;
 195        sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 196        sb->s_blocksize_bits = 12;
 197        sb->s_magic = CODA_SUPER_MAGIC;
 198        sb->s_op = &coda_super_operations;
 199        sb->s_d_op = &coda_dentry_operations;
 200        sb->s_bdi = &vc->bdi;
 201
 202        /* get root fid from Venus: this needs the root inode */
 203        error = venus_rootfid(sb, &fid);
 204        if ( error ) {
 205                pr_warn("%s: coda_get_rootfid failed with %d\n",
 206                        __func__, error);
 207                goto error;
 208        }
 209        pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
 210        
 211        /* make root inode */
 212        root = coda_cnode_make(&fid, sb);
 213        if (IS_ERR(root)) {
 214                error = PTR_ERR(root);
 215                pr_warn("Failure of coda_cnode_make for root: error %d\n",
 216                        error);
 217                goto error;
 218        } 
 219
 220        pr_info("%s: rootinode is %ld dev %s\n",
 221                __func__, root->i_ino, root->i_sb->s_id);
 222        sb->s_root = d_make_root(root);
 223        if (!sb->s_root) {
 224                error = -EINVAL;
 225                goto error;
 226        }
 227        return 0;
 228
 229error:
 230        mutex_lock(&vc->vc_mutex);
 231        bdi_destroy(&vc->bdi);
 232        vc->vc_sb = NULL;
 233        sb->s_fs_info = NULL;
 234unlock_out:
 235        mutex_unlock(&vc->vc_mutex);
 236        return error;
 237}
 238
 239static void coda_put_super(struct super_block *sb)
 240{
 241        struct venus_comm *vcp = coda_vcp(sb);
 242        mutex_lock(&vcp->vc_mutex);
 243        bdi_destroy(&vcp->bdi);
 244        vcp->vc_sb = NULL;
 245        sb->s_fs_info = NULL;
 246        mutex_unlock(&vcp->vc_mutex);
 247
 248        pr_info("Bye bye.\n");
 249}
 250
 251static void coda_evict_inode(struct inode *inode)
 252{
 253        truncate_inode_pages_final(&inode->i_data);
 254        clear_inode(inode);
 255        coda_cache_clear_inode(inode);
 256}
 257
 258int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 259{
 260        int err = coda_revalidate_inode(dentry->d_inode);
 261        if (!err)
 262                generic_fillattr(dentry->d_inode, stat);
 263        return err;
 264}
 265
 266int coda_setattr(struct dentry *de, struct iattr *iattr)
 267{
 268        struct inode *inode = de->d_inode;
 269        struct coda_vattr vattr;
 270        int error;
 271
 272        memset(&vattr, 0, sizeof(vattr)); 
 273
 274        inode->i_ctime = CURRENT_TIME_SEC;
 275        coda_iattr_to_vattr(iattr, &vattr);
 276        vattr.va_type = C_VNON; /* cannot set type */
 277
 278        /* Venus is responsible for truncating the container-file!!! */
 279        error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 280
 281        if (!error) {
 282                coda_vattr_to_iattr(inode, &vattr); 
 283                coda_cache_clear_inode(inode);
 284        }
 285        return error;
 286}
 287
 288const struct inode_operations coda_file_inode_operations = {
 289        .permission     = coda_permission,
 290        .getattr        = coda_getattr,
 291        .setattr        = coda_setattr,
 292};
 293
 294static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 295{
 296        int error;
 297        
 298        error = venus_statfs(dentry, buf);
 299
 300        if (error) {
 301                /* fake something like AFS does */
 302                buf->f_blocks = 9000000;
 303                buf->f_bfree  = 9000000;
 304                buf->f_bavail = 9000000;
 305                buf->f_files  = 9000000;
 306                buf->f_ffree  = 9000000;
 307        }
 308
 309        /* and fill in the rest */
 310        buf->f_type = CODA_SUPER_MAGIC;
 311        buf->f_bsize = 4096;
 312        buf->f_namelen = CODA_MAXNAMLEN;
 313
 314        return 0; 
 315}
 316
 317/* init_coda: used by filesystems.c to register coda */
 318
 319static struct dentry *coda_mount(struct file_system_type *fs_type,
 320        int flags, const char *dev_name, void *data)
 321{
 322        return mount_nodev(fs_type, flags, data, coda_fill_super);
 323}
 324
 325struct file_system_type coda_fs_type = {
 326        .owner          = THIS_MODULE,
 327        .name           = "coda",
 328        .mount          = coda_mount,
 329        .kill_sb        = kill_anon_super,
 330        .fs_flags       = FS_BINARY_MOUNTDATA,
 331};
 332MODULE_ALIAS_FS("coda");
 333
 334
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