linux/fs/coda/inode.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Super block/filesystem wide operations
   4 *
   5 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and 
   6 * Michael Callahan <callahan@maths.ox.ac.uk> 
   7 * 
   8 * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
   9 * Copyright (C) Carnegie Mellon University
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/kernel.h>
  14#include <linux/mm.h>
  15#include <linux/string.h>
  16#include <linux/stat.h>
  17#include <linux/errno.h>
  18#include <linux/unistd.h>
  19#include <linux/mutex.h>
  20#include <linux/spinlock.h>
  21#include <linux/file.h>
  22#include <linux/vfs.h>
  23#include <linux/slab.h>
  24#include <linux/pid_namespace.h>
  25#include <linux/uaccess.h>
  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 = GLOBAL_ROOT_UID;
  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 __init coda_init_inodecache(void)
  76{
  77        coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  78                                sizeof(struct coda_inode_info), 0,
  79                                SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
  80                                SLAB_ACCOUNT, 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        sync_filesystem(sb);
  99        *flags |= SB_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                pr_warn("%s: Bad mount data\n", __func__);
 122                return -1;
 123        }
 124
 125        if (data->version != CODA_MOUNT_VERSION) {
 126                pr_warn("%s: Bad mount version\n", __func__);
 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                pr_warn("%s: Bad minor number\n", __func__);
 144                return -1;
 145        }
 146
 147        return idx;
 148Ebadf:
 149        pr_warn("%s: Bad file\n", __func__);
 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        pr_info("%s: device index: %i\n", __func__,  idx);
 171
 172        vc = &coda_comms[idx];
 173        mutex_lock(&vc->vc_mutex);
 174
 175        if (!vc->vc_inuse) {
 176                pr_warn("%s: No pseudo device\n", __func__);
 177                error = -EINVAL;
 178                goto unlock_out;
 179        }
 180
 181        if (vc->vc_sb) {
 182                pr_warn("%s: Device already mounted\n", __func__);
 183                error = -EBUSY;
 184                goto unlock_out;
 185        }
 186
 187        vc->vc_sb = sb;
 188        mutex_unlock(&vc->vc_mutex);
 189
 190        sb->s_fs_info = vc;
 191        sb->s_flags |= SB_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
 198        error = super_setup_bdi(sb);
 199        if (error)
 200                goto error;
 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        vc->vc_sb = NULL;
 232        sb->s_fs_info = NULL;
 233unlock_out:
 234        mutex_unlock(&vc->vc_mutex);
 235        return error;
 236}
 237
 238static void coda_put_super(struct super_block *sb)
 239{
 240        struct venus_comm *vcp = coda_vcp(sb);
 241        mutex_lock(&vcp->vc_mutex);
 242        vcp->vc_sb = NULL;
 243        sb->s_fs_info = NULL;
 244        mutex_unlock(&vcp->vc_mutex);
 245
 246        pr_info("Bye bye.\n");
 247}
 248
 249static void coda_evict_inode(struct inode *inode)
 250{
 251        truncate_inode_pages_final(&inode->i_data);
 252        clear_inode(inode);
 253        coda_cache_clear_inode(inode);
 254}
 255
 256int coda_getattr(const struct path *path, struct kstat *stat,
 257                 u32 request_mask, unsigned int flags)
 258{
 259        int err = coda_revalidate_inode(d_inode(path->dentry));
 260        if (!err)
 261                generic_fillattr(d_inode(path->dentry), stat);
 262        return err;
 263}
 264
 265int coda_setattr(struct dentry *de, struct iattr *iattr)
 266{
 267        struct inode *inode = d_inode(de);
 268        struct coda_vattr vattr;
 269        int error;
 270
 271        memset(&vattr, 0, sizeof(vattr)); 
 272
 273        inode->i_ctime = current_time(inode);
 274        coda_iattr_to_vattr(iattr, &vattr);
 275        vattr.va_type = C_VNON; /* cannot set type */
 276
 277        /* Venus is responsible for truncating the container-file!!! */
 278        error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 279
 280        if (!error) {
 281                coda_vattr_to_iattr(inode, &vattr); 
 282                coda_cache_clear_inode(inode);
 283        }
 284        return error;
 285}
 286
 287const struct inode_operations coda_file_inode_operations = {
 288        .permission     = coda_permission,
 289        .getattr        = coda_getattr,
 290        .setattr        = coda_setattr,
 291};
 292
 293static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 294{
 295        int error;
 296        
 297        error = venus_statfs(dentry, buf);
 298
 299        if (error) {
 300                /* fake something like AFS does */
 301                buf->f_blocks = 9000000;
 302                buf->f_bfree  = 9000000;
 303                buf->f_bavail = 9000000;
 304                buf->f_files  = 9000000;
 305                buf->f_ffree  = 9000000;
 306        }
 307
 308        /* and fill in the rest */
 309        buf->f_type = CODA_SUPER_MAGIC;
 310        buf->f_bsize = 4096;
 311        buf->f_namelen = CODA_MAXNAMLEN;
 312
 313        return 0; 
 314}
 315
 316/* init_coda: used by filesystems.c to register coda */
 317
 318static struct dentry *coda_mount(struct file_system_type *fs_type,
 319        int flags, const char *dev_name, void *data)
 320{
 321        return mount_nodev(fs_type, flags, data, coda_fill_super);
 322}
 323
 324struct file_system_type coda_fs_type = {
 325        .owner          = THIS_MODULE,
 326        .name           = "coda",
 327        .mount          = coda_mount,
 328        .kill_sb        = kill_anon_super,
 329        .fs_flags       = FS_BINARY_MOUNTDATA,
 330};
 331MODULE_ALIAS_FS("coda");
 332
 333