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