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
  25#include <asm/uaccess.h>
  26
  27#include <linux/fs.h>
  28#include <linux/vmalloc.h>
  29
  30#include <linux/coda.h>
  31#include <linux/coda_psdev.h>
  32#include "coda_linux.h"
  33#include "coda_cache.h"
  34
  35#include "coda_int.h"
  36
  37/* VFS super_block ops */
  38static void coda_evict_inode(struct inode *);
  39static void coda_put_super(struct super_block *);
  40static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  41
  42static struct kmem_cache * coda_inode_cachep;
  43
  44static struct inode *coda_alloc_inode(struct super_block *sb)
  45{
  46        struct coda_inode_info *ei;
  47        ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
  48        if (!ei)
  49                return NULL;
  50        memset(&ei->c_fid, 0, sizeof(struct CodaFid));
  51        ei->c_flags = 0;
  52        ei->c_uid = GLOBAL_ROOT_UID;
  53        ei->c_cached_perm = 0;
  54        spin_lock_init(&ei->c_lock);
  55        return &ei->vfs_inode;
  56}
  57
  58static void coda_i_callback(struct rcu_head *head)
  59{
  60        struct inode *inode = container_of(head, struct inode, i_rcu);
  61        kmem_cache_free(coda_inode_cachep, ITOC(inode));
  62}
  63
  64static void coda_destroy_inode(struct inode *inode)
  65{
  66        call_rcu(&inode->i_rcu, coda_i_callback);
  67}
  68
  69static void init_once(void *foo)
  70{
  71        struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  72
  73        inode_init_once(&ei->vfs_inode);
  74}
  75
  76int coda_init_inodecache(void)
  77{
  78        coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  79                                sizeof(struct coda_inode_info),
  80                                0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  81                                init_once);
  82        if (coda_inode_cachep == NULL)
  83                return -ENOMEM;
  84        return 0;
  85}
  86
  87void coda_destroy_inodecache(void)
  88{
  89        /*
  90         * Make sure all delayed rcu free inodes are flushed before we
  91         * destroy cache.
  92         */
  93        rcu_barrier();
  94        kmem_cache_destroy(coda_inode_cachep);
  95}
  96
  97static int coda_remount(struct super_block *sb, int *flags, char *data)
  98{
  99        *flags |= MS_NOATIME;
 100        return 0;
 101}
 102
 103/* exported operations */
 104static const struct super_operations coda_super_operations =
 105{
 106        .alloc_inode    = coda_alloc_inode,
 107        .destroy_inode  = coda_destroy_inode,
 108        .evict_inode    = coda_evict_inode,
 109        .put_super      = coda_put_super,
 110        .statfs         = coda_statfs,
 111        .remount_fs     = coda_remount,
 112};
 113
 114static int get_device_index(struct coda_mount_data *data)
 115{
 116        struct fd f;
 117        struct inode *inode;
 118        int idx;
 119
 120        if (data == NULL) {
 121                printk("coda_read_super: Bad mount data\n");
 122                return -1;
 123        }
 124
 125        if (data->version != CODA_MOUNT_VERSION) {
 126                printk("coda_read_super: Bad mount version\n");
 127                return -1;
 128        }
 129
 130        f = fdget(data->fd);
 131        if (!f.file)
 132                goto Ebadf;
 133        inode = file_inode(f.file);
 134        if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 135                fdput(f);
 136                goto Ebadf;
 137        }
 138
 139        idx = iminor(inode);
 140        fdput(f);
 141
 142        if (idx < 0 || idx >= MAX_CODADEVS) {
 143                printk("coda_read_super: Bad minor number\n");
 144                return -1;
 145        }
 146
 147        return idx;
 148Ebadf:
 149        printk("coda_read_super: Bad file\n");
 150        return -1;
 151}
 152
 153static int coda_fill_super(struct super_block *sb, void *data, int silent)
 154{
 155        struct inode *root = NULL;
 156        struct venus_comm *vc;
 157        struct CodaFid fid;
 158        int error;
 159        int idx;
 160
 161        if (task_active_pid_ns(current) != &init_pid_ns)
 162                return -EINVAL;
 163
 164        idx = get_device_index((struct coda_mount_data *) data);
 165
 166        /* Ignore errors in data, for backward compatibility */
 167        if(idx == -1)
 168                idx = 0;
 169        
 170        printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 171
 172        vc = &coda_comms[idx];
 173        mutex_lock(&vc->vc_mutex);
 174
 175        if (!vc->vc_inuse) {
 176                printk("coda_read_super: No pseudo device\n");
 177                error = -EINVAL;
 178                goto unlock_out;
 179        }
 180
 181        if (vc->vc_sb) {
 182                printk("coda_read_super: Device already mounted\n");
 183                error = -EBUSY;
 184                goto unlock_out;
 185        }
 186
 187        error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 188        if (error)
 189                goto unlock_out;
 190
 191        vc->vc_sb = sb;
 192        mutex_unlock(&vc->vc_mutex);
 193
 194        sb->s_fs_info = vc;
 195        sb->s_flags |= MS_NOATIME;
 196        sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 197        sb->s_blocksize_bits = 12;
 198        sb->s_magic = CODA_SUPER_MAGIC;
 199        sb->s_op = &coda_super_operations;
 200        sb->s_d_op = &coda_dentry_operations;
 201        sb->s_bdi = &vc->bdi;
 202
 203        /* get root fid from Venus: this needs the root inode */
 204        error = venus_rootfid(sb, &fid);
 205        if ( error ) {
 206                printk("coda_read_super: coda_get_rootfid failed with %d\n",
 207                       error);
 208                goto error;
 209        }
 210        printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 211        
 212        /* make root inode */
 213        root = coda_cnode_make(&fid, sb);
 214        if (IS_ERR(root)) {
 215                error = PTR_ERR(root);
 216                printk("Failure of coda_cnode_make for root: error %d\n", error);
 217                goto error;
 218        } 
 219
 220        printk("coda_read_super: rootinode is %ld dev %s\n", 
 221               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        printk("Coda: Bye bye.\n");
 249}
 250
 251static void coda_evict_inode(struct inode *inode)
 252{
 253        truncate_inode_pages(&inode->i_data, 0);
 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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