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 "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_free_inode(struct inode *inode)
  58{
  59        kmem_cache_free(coda_inode_cachep, ITOC(inode));
  60}
  61
  62static void init_once(void *foo)
  63{
  64        struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  65
  66        inode_init_once(&ei->vfs_inode);
  67}
  68
  69int __init coda_init_inodecache(void)
  70{
  71        coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  72                                sizeof(struct coda_inode_info), 0,
  73                                SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
  74                                SLAB_ACCOUNT, init_once);
  75        if (coda_inode_cachep == NULL)
  76                return -ENOMEM;
  77        return 0;
  78}
  79
  80void coda_destroy_inodecache(void)
  81{
  82        /*
  83         * Make sure all delayed rcu free inodes are flushed before we
  84         * destroy cache.
  85         */
  86        rcu_barrier();
  87        kmem_cache_destroy(coda_inode_cachep);
  88}
  89
  90static int coda_remount(struct super_block *sb, int *flags, char *data)
  91{
  92        sync_filesystem(sb);
  93        *flags |= SB_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        .free_inode     = coda_free_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 fd f;
 111        struct inode *inode;
 112        int idx;
 113
 114        if (data == NULL) {
 115                pr_warn("%s: Bad mount data\n", __func__);
 116                return -1;
 117        }
 118
 119        if (data->version != CODA_MOUNT_VERSION) {
 120                pr_warn("%s: Bad mount version\n", __func__);
 121                return -1;
 122        }
 123
 124        f = fdget(data->fd);
 125        if (!f.file)
 126                goto Ebadf;
 127        inode = file_inode(f.file);
 128        if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 129                fdput(f);
 130                goto Ebadf;
 131        }
 132
 133        idx = iminor(inode);
 134        fdput(f);
 135
 136        if (idx < 0 || idx >= MAX_CODADEVS) {
 137                pr_warn("%s: Bad minor number\n", __func__);
 138                return -1;
 139        }
 140
 141        return idx;
 142Ebadf:
 143        pr_warn("%s: Bad file\n", __func__);
 144        return -1;
 145}
 146
 147static int coda_fill_super(struct super_block *sb, void *data, int silent)
 148{
 149        struct inode *root = NULL;
 150        struct venus_comm *vc;
 151        struct CodaFid fid;
 152        int error;
 153        int idx;
 154
 155        if (task_active_pid_ns(current) != &init_pid_ns)
 156                return -EINVAL;
 157
 158        idx = get_device_index((struct coda_mount_data *) data);
 159
 160        /* Ignore errors in data, for backward compatibility */
 161        if(idx == -1)
 162                idx = 0;
 163        
 164        pr_info("%s: device index: %i\n", __func__,  idx);
 165
 166        vc = &coda_comms[idx];
 167        mutex_lock(&vc->vc_mutex);
 168
 169        if (!vc->vc_inuse) {
 170                pr_warn("%s: No pseudo device\n", __func__);
 171                error = -EINVAL;
 172                goto unlock_out;
 173        }
 174
 175        if (vc->vc_sb) {
 176                pr_warn("%s: Device already mounted\n", __func__);
 177                error = -EBUSY;
 178                goto unlock_out;
 179        }
 180
 181        vc->vc_sb = sb;
 182        mutex_unlock(&vc->vc_mutex);
 183
 184        sb->s_fs_info = vc;
 185        sb->s_flags |= SB_NOATIME;
 186        sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 187        sb->s_blocksize_bits = 12;
 188        sb->s_magic = CODA_SUPER_MAGIC;
 189        sb->s_op = &coda_super_operations;
 190        sb->s_d_op = &coda_dentry_operations;
 191        sb->s_time_gran = 1;
 192        sb->s_time_min = S64_MIN;
 193        sb->s_time_max = S64_MAX;
 194
 195        error = super_setup_bdi(sb);
 196        if (error)
 197                goto error;
 198
 199        /* get root fid from Venus: this needs the root inode */
 200        error = venus_rootfid(sb, &fid);
 201        if ( error ) {
 202                pr_warn("%s: coda_get_rootfid failed with %d\n",
 203                        __func__, error);
 204                goto error;
 205        }
 206        pr_info("%s: rootfid is %s\n", __func__, 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                pr_warn("Failure of coda_cnode_make for root: error %d\n",
 213                        error);
 214                goto error;
 215        } 
 216
 217        pr_info("%s: rootinode is %ld dev %s\n",
 218                __func__, root->i_ino, root->i_sb->s_id);
 219        sb->s_root = d_make_root(root);
 220        if (!sb->s_root) {
 221                error = -EINVAL;
 222                goto error;
 223        }
 224        return 0;
 225
 226error:
 227        mutex_lock(&vc->vc_mutex);
 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        vcp->vc_sb = NULL;
 240        sb->s_fs_info = NULL;
 241        mutex_unlock(&vcp->vc_mutex);
 242        mutex_destroy(&vcp->vc_mutex);
 243
 244        pr_info("Bye bye.\n");
 245}
 246
 247static void coda_evict_inode(struct inode *inode)
 248{
 249        truncate_inode_pages_final(&inode->i_data);
 250        clear_inode(inode);
 251        coda_cache_clear_inode(inode);
 252}
 253
 254int coda_getattr(struct user_namespace *mnt_userns, const struct path *path,
 255                 struct kstat *stat, u32 request_mask, unsigned int flags)
 256{
 257        int err = coda_revalidate_inode(d_inode(path->dentry));
 258        if (!err)
 259                generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
 260        return err;
 261}
 262
 263int coda_setattr(struct user_namespace *mnt_userns, struct dentry *de,
 264                 struct iattr *iattr)
 265{
 266        struct inode *inode = d_inode(de);
 267        struct coda_vattr vattr;
 268        int error;
 269
 270        memset(&vattr, 0, sizeof(vattr)); 
 271
 272        inode->i_ctime = current_time(inode);
 273        coda_iattr_to_vattr(iattr, &vattr);
 274        vattr.va_type = C_VNON; /* cannot set type */
 275
 276        /* Venus is responsible for truncating the container-file!!! */
 277        error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 278
 279        if (!error) {
 280                coda_vattr_to_iattr(inode, &vattr); 
 281                coda_cache_clear_inode(inode);
 282        }
 283        return error;
 284}
 285
 286const struct inode_operations coda_file_inode_operations = {
 287        .permission     = coda_permission,
 288        .getattr        = coda_getattr,
 289        .setattr        = coda_setattr,
 290};
 291
 292static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 293{
 294        int error;
 295        
 296        error = venus_statfs(dentry, buf);
 297
 298        if (error) {
 299                /* fake something like AFS does */
 300                buf->f_blocks = 9000000;
 301                buf->f_bfree  = 9000000;
 302                buf->f_bavail = 9000000;
 303                buf->f_files  = 9000000;
 304                buf->f_ffree  = 9000000;
 305        }
 306
 307        /* and fill in the rest */
 308        buf->f_type = CODA_SUPER_MAGIC;
 309        buf->f_bsize = 4096;
 310        buf->f_namelen = CODA_MAXNAMLEN;
 311
 312        return 0; 
 313}
 314
 315/* init_coda: used by filesystems.c to register coda */
 316
 317static struct dentry *coda_mount(struct file_system_type *fs_type,
 318        int flags, const char *dev_name, void *data)
 319{
 320        return mount_nodev(fs_type, flags, data, coda_fill_super);
 321}
 322
 323struct file_system_type coda_fs_type = {
 324        .owner          = THIS_MODULE,
 325        .name           = "coda",
 326        .mount          = coda_mount,
 327        .kill_sb        = kill_anon_super,
 328        .fs_flags       = FS_BINARY_MOUNTDATA,
 329};
 330MODULE_ALIAS_FS("coda");
 331
 332