fs/coda/inode.c

   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 */
  37 static void coda_evict_inode(struct inode *);
  38 static void coda_put_super(struct super_block *);
  39 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  40
  41 static struct kmem_cache * coda_inode_cachep;
  42
  43 static 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
  57 static void coda_free_inode(struct inode *inode)
  58 {
  59         kmem_cache_free(coda_inode_cachep, ITOC(inode));
  60 }
  61
  62 static 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
  69 int __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
  80 void 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
  90 static 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 */
  98 static 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
 108 static 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;
 142 Ebadf:
 143         pr_warn("%s: Bad file\n", __func__);
 144         return -1;
 145 }
 146
 147 static 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
 226 error:
 227         mutex_lock(&vc->vc_mutex);
 228         vc->vc_sb = NULL;
 229         sb->s_fs_info = NULL;
 230 unlock_out:
 231         mutex_unlock(&vc->vc_mutex);
 232         return error;
 233 }
 234
 235 static 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
 247 static 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
 254 int coda_getattr(const struct path *path, struct kstat *stat,
 255                  u32 request_mask, unsigned int flags)
 256 {
 257         int err = coda_revalidate_inode(d_inode(path->dentry));
 258         if (!err)
 259                 generic_fillattr(d_inode(path->dentry), stat);
 260         return err;
 261 }
 262
 263 int coda_setattr(struct dentry *de, struct iattr *iattr)
 264 {
 265         struct inode *inode = d_inode(de);
 266         struct coda_vattr vattr;
 267         int error;
 268
 269         memset(&vattr, 0, sizeof(vattr));
 270
 271         inode->i_ctime = current_time(inode);
 272         coda_iattr_to_vattr(iattr, &vattr);
 273         vattr.va_type = C_VNON; /* cannot set type */
 274
 275         /* Venus is responsible for truncating the container-file!!! */
 276         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 277
 278         if (!error) {
 279                 coda_vattr_to_iattr(inode, &vattr);
 280                 coda_cache_clear_inode(inode);
 281         }
 282         return error;
 283 }
 284
 285 const struct inode_operations coda_file_inode_operations = {
 286         .permission     = coda_permission,
 287         .getattr        = coda_getattr,
 288         .setattr        = coda_setattr,
 289 };
 290
 291 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 292 {
 293         int error;
 294
 295         error = venus_statfs(dentry, buf);
 296
 297         if (error) {
 298                 /* fake something like AFS does */
 299                 buf->f_blocks = 9000000;
 300                 buf->f_bfree  = 9000000;
 301                 buf->f_bavail = 9000000;
 302                 buf->f_files  = 9000000;
 303                 buf->f_ffree  = 9000000;
 304         }
 305
 306         /* and fill in the rest */
 307         buf->f_type = CODA_SUPER_MAGIC;
 308         buf->f_bsize = 4096;
 309         buf->f_namelen = CODA_MAXNAMLEN;
 310
 311         return 0;
 312 }
 313
 314 /* init_coda: used by filesystems.c to register coda */
 315
 316 static struct dentry *coda_mount(struct file_system_type *fs_type,
 317         int flags, const char *dev_name, void *data)
 318 {
 319         return mount_nodev(fs_type, flags, data, coda_fill_super);
 320 }
 321
 322 struct file_system_type coda_fs_type = {
 323         .owner          = THIS_MODULE,
 324         .name           = "coda",
 325         .mount          = coda_mount,
 326         .kill_sb        = kill_anon_super,
 327         .fs_flags       = FS_BINARY_MOUNTDATA,
 328 };
 329 MODULE_ALIAS_FS("coda");
 330