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        /*
  89         * Make sure all delayed rcu free inodes are flushed before we
  90         * destroy cache.
  91         */
  92        rcu_barrier();
  93        kmem_cache_destroy(coda_inode_cachep);
  94}
  95
  96static int coda_remount(struct super_block *sb, int *flags, char *data)
  97{
  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                printk("coda_read_super: Bad mount data\n");
 121                return -1;
 122        }
 123
 124        if (data->version != CODA_MOUNT_VERSION) {
 125                printk("coda_read_super: Bad mount version\n");
 126                return -1;
 127        }
 128
 129        f = fdget(data->fd);
 130        if (!f.file)
 131                goto Ebadf;
 132        inode = f.file->f_path.dentry->d_inode;
 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                printk("coda_read_super: Bad minor number\n");
 143                return -1;
 144        }
 145
 146        return idx;
 147Ebadf:
 148        printk("coda_read_super: Bad file\n");
 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        idx = get_device_index((struct coda_mount_data *) data);
 161
 162        /* Ignore errors in data, for backward compatibility */
 163        if(idx == -1)
 164                idx = 0;
 165        
 166        printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 167
 168        vc = &coda_comms[idx];
 169        mutex_lock(&vc->vc_mutex);
 170
 171        if (!vc->vc_inuse) {
 172                printk("coda_read_super: No pseudo device\n");
 173                error = -EINVAL;
 174                goto unlock_out;
 175        }
 176
 177        if (vc->vc_sb) {
 178                printk("coda_read_super: Device already mounted\n");
 179                error = -EBUSY;
 180                goto unlock_out;
 181        }
 182
 183        error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 184        if (error)
 185                goto unlock_out;
 186
 187        vc->vc_sb = sb;
 188        mutex_unlock(&vc->vc_mutex);
 189
 190        sb->s_fs_info = vc;
 191        sb->s_flags |= MS_NOATIME;
 192        sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 193        sb->s_blocksize_bits = 12;
 194        sb->s_magic = CODA_SUPER_MAGIC;
 195        sb->s_op = &coda_super_operations;
 196        sb->s_d_op = &coda_dentry_operations;
 197        sb->s_bdi = &vc->bdi;
 198
 199        /* get root fid from Venus: this needs the root inode */
 200        error = venus_rootfid(sb, &fid);
 201        if ( error ) {
 202                printk("coda_read_super: coda_get_rootfid failed with %d\n",
 203                       error);
 204                goto error;
 205        }
 206        printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 207        
 208        /* make root inode */
 209        root = coda_cnode_make(&fid, sb);
 210        if (IS_ERR(root)) {
 211                error = PTR_ERR(root);
 212                printk("Failure of coda_cnode_make for root: error %d\n", error);
 213                goto error;
 214        } 
 215
 216        printk("coda_read_super: rootinode is %ld dev %s\n", 
 217               root->i_ino, root->i_sb->s_id);
 218        sb->s_root = d_make_root(root);
 219        if (!sb->s_root) {
 220                error = -EINVAL;
 221                goto error;
 222        }
 223        return 0;
 224
 225error:
 226        mutex_lock(&vc->vc_mutex);
 227        bdi_destroy(&vc->bdi);
 228        vc->vc_sb = NULL;
 229        sb->s_fs_info = NULL;
 230unlock_out:
 231        mutex_unlock(&vc->vc_mutex);
 232        return error;
 233}
 234
 235static void coda_put_super(struct super_block *sb)
 236{
 237        struct venus_comm *vcp = coda_vcp(sb);
 238        mutex_lock(&vcp->vc_mutex);
 239        bdi_destroy(&vcp->bdi);
 240        vcp->vc_sb = NULL;
 241        sb->s_fs_info = NULL;
 242        mutex_unlock(&vcp->vc_mutex);
 243
 244        printk("Coda: Bye bye.\n");
 245}
 246
 247static void coda_evict_inode(struct inode *inode)
 248{
 249        truncate_inode_pages(&inode->i_data, 0);
 250        clear_inode(inode);
 251        coda_cache_clear_inode(inode);
 252}
 253
 254int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 255{
 256        int err = coda_revalidate_inode(dentry);
 257        if (!err)
 258                generic_fillattr(dentry->d_inode, stat);
 259        return err;
 260}
 261
 262int coda_setattr(struct dentry *de, struct iattr *iattr)
 263{
 264        struct inode *inode = de->d_inode;
 265        struct coda_vattr vattr;
 266        int error;
 267
 268        memset(&vattr, 0, sizeof(vattr)); 
 269
 270        inode->i_ctime = CURRENT_TIME_SEC;
 271        coda_iattr_to_vattr(iattr, &vattr);
 272        vattr.va_type = C_VNON; /* cannot set type */
 273
 274        /* Venus is responsible for truncating the container-file!!! */
 275        error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 276
 277        if (!error) {
 278                coda_vattr_to_iattr(inode, &vattr); 
 279                coda_cache_clear_inode(inode);
 280        }
 281        return error;
 282}
 283
 284const struct inode_operations coda_file_inode_operations = {
 285        .permission     = coda_permission,
 286        .getattr        = coda_getattr,
 287        .setattr        = coda_setattr,
 288};
 289
 290static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 291{
 292        int error;
 293        
 294        error = venus_statfs(dentry, buf);
 295
 296        if (error) {
 297                /* fake something like AFS does */
 298                buf->f_blocks = 9000000;
 299                buf->f_bfree  = 9000000;
 300                buf->f_bavail = 9000000;
 301                buf->f_files  = 9000000;
 302                buf->f_ffree  = 9000000;
 303        }
 304
 305        /* and fill in the rest */
 306        buf->f_type = CODA_SUPER_MAGIC;
 307        buf->f_bsize = 4096;
 308        buf->f_namelen = CODA_MAXNAMLEN;
 309
 310        return 0; 
 311}
 312
 313/* init_coda: used by filesystems.c to register coda */
 314
 315static struct dentry *coda_mount(struct file_system_type *fs_type,
 316        int flags, const char *dev_name, void *data)
 317{
 318        return mount_nodev(fs_type, flags, data, coda_fill_super);
 319}
 320
 321struct file_system_type coda_fs_type = {
 322        .owner          = THIS_MODULE,
 323        .name           = "coda",
 324        .mount          = coda_mount,
 325        .kill_sb        = kill_anon_super,
 326        .fs_flags       = FS_BINARY_MOUNTDATA,
 327};
 328
 329
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