fs/coda/inode.c

   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/system.h>
  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 */
  38 static void coda_evict_inode(struct inode *);
  39 static void coda_put_super(struct super_block *);
  40 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  41
  42 static struct kmem_cache * coda_inode_cachep;
  43
  44 static 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 = 0;
  53         ei->c_cached_perm = 0;
  54         spin_lock_init(&ei->c_lock);
  55         return &ei->vfs_inode;
  56 }
  57
  58 static void coda_i_callback(struct rcu_head *head)
  59 {
  60         struct inode *inode = container_of(head, struct inode, i_rcu);
  61         INIT_LIST_HEAD(&inode->i_dentry);
  62         kmem_cache_free(coda_inode_cachep, ITOC(inode));
  63 }
  64
  65 static void coda_destroy_inode(struct inode *inode)
  66 {
  67         call_rcu(&inode->i_rcu, coda_i_callback);
  68 }
  69
  70 static void init_once(void *foo)
  71 {
  72         struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  73
  74         inode_init_once(&ei->vfs_inode);
  75 }
  76
  77 int coda_init_inodecache(void)
  78 {
  79         coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  80                                 sizeof(struct coda_inode_info),
  81                                 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  82                                 init_once);
  83         if (coda_inode_cachep == NULL)
  84                 return -ENOMEM;
  85         return 0;
  86 }
  87
  88 void coda_destroy_inodecache(void)
  89 {
  90         kmem_cache_destroy(coda_inode_cachep);
  91 }
  92
  93 static int coda_remount(struct super_block *sb, int *flags, char *data)
  94 {
  95         *flags |= MS_NOATIME;
  96         return 0;
  97 }
  98
  99 /* exported operations */
 100 static const struct super_operations coda_super_operations =
 101 {
 102         .alloc_inode    = coda_alloc_inode,
 103         .destroy_inode  = coda_destroy_inode,
 104         .evict_inode    = coda_evict_inode,
 105         .put_super      = coda_put_super,
 106         .statfs         = coda_statfs,
 107         .remount_fs     = coda_remount,
 108 };
 109
 110 static int get_device_index(struct coda_mount_data *data)
 111 {
 112         struct file *file;
 113         struct inode *inode;
 114         int idx;
 115
 116         if(data == NULL) {
 117                 printk("coda_read_super: Bad mount data\n");
 118                 return -1;
 119         }
 120
 121         if(data->version != CODA_MOUNT_VERSION) {
 122                 printk("coda_read_super: Bad mount version\n");
 123                 return -1;
 124         }
 125
 126         file = fget(data->fd);
 127         inode = NULL;
 128         if(file)
 129                 inode = file->f_path.dentry->d_inode;
 130
 131         if(!inode || !S_ISCHR(inode->i_mode) ||
 132            imajor(inode) != CODA_PSDEV_MAJOR) {
 133                 if(file)
 134                         fput(file);
 135
 136                 printk("coda_read_super: Bad file\n");
 137                 return -1;
 138         }
 139
 140         idx = iminor(inode);
 141         fput(file);
 142
 143         if(idx < 0 || idx >= MAX_CODADEVS) {
 144                 printk("coda_read_super: Bad minor number\n");
 145                 return -1;
 146         }
 147
 148         return idx;
 149 }
 150
 151 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 152 {
 153         struct inode *root = NULL;
 154         struct venus_comm *vc;
 155         struct CodaFid fid;
 156         int error;
 157         int idx;
 158
 159         idx = get_device_index((struct coda_mount_data *) data);
 160
 161         /* Ignore errors in data, for backward compatibility */
 162         if(idx == -1)
 163                 idx = 0;
 164
 165         printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 166
 167         vc = &coda_comms[idx];
 168         mutex_lock(&vc->vc_mutex);
 169
 170         if (!vc->vc_inuse) {
 171                 printk("coda_read_super: No pseudo device\n");
 172                 error = -EINVAL;
 173                 goto unlock_out;
 174         }
 175
 176         if (vc->vc_sb) {
 177                 printk("coda_read_super: Device already mounted\n");
 178                 error = -EBUSY;
 179                 goto unlock_out;
 180         }
 181
 182         error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 183         if (error)
 184                 goto unlock_out;
 185
 186         vc->vc_sb = sb;
 187         mutex_unlock(&vc->vc_mutex);
 188
 189         sb->s_fs_info = vc;
 190         sb->s_flags |= MS_NOATIME;
 191         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 192         sb->s_blocksize_bits = 12;
 193         sb->s_magic = CODA_SUPER_MAGIC;
 194         sb->s_op = &coda_super_operations;
 195         sb->s_d_op = &coda_dentry_operations;
 196         sb->s_bdi = &vc->bdi;
 197
 198         /* get root fid from Venus: this needs the root inode */
 199         error = venus_rootfid(sb, &fid);
 200         if ( error ) {
 201                 printk("coda_read_super: coda_get_rootfid failed with %d\n",
 202                        error);
 203                 goto error;
 204         }
 205         printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 206
 207         /* make root inode */
 208         error = coda_cnode_make(&root, &fid, sb);
 209         if ( error || !root ) {
 210             printk("Failure of coda_cnode_make for root: error %d\n", error);
 211             goto error;
 212         }
 213
 214         printk("coda_read_super: rootinode is %ld dev %s\n",
 215                root->i_ino, root->i_sb->s_id);
 216         sb->s_root = d_alloc_root(root);
 217         if (!sb->s_root) {
 218                 error = -EINVAL;
 219                 goto error;
 220         }
 221         return 0;
 222
 223 error:
 224         if (root)
 225                 iput(root);
 226
 227         mutex_lock(&vc->vc_mutex);
 228         bdi_destroy(&vc->bdi);
 229         vc->vc_sb = NULL;
 230         sb->s_fs_info = NULL;
 231 unlock_out:
 232         mutex_unlock(&vc->vc_mutex);
 233         return error;
 234 }
 235
 236 static void coda_put_super(struct super_block *sb)
 237 {
 238         struct venus_comm *vcp = coda_vcp(sb);
 239         mutex_lock(&vcp->vc_mutex);
 240         bdi_destroy(&vcp->bdi);
 241         vcp->vc_sb = NULL;
 242         sb->s_fs_info = NULL;
 243         mutex_unlock(&vcp->vc_mutex);
 244
 245         printk("Coda: Bye bye.\n");
 246 }
 247
 248 static void coda_evict_inode(struct inode *inode)
 249 {
 250         truncate_inode_pages(&inode->i_data, 0);
 251         end_writeback(inode);
 252         coda_cache_clear_inode(inode);
 253 }
 254
 255 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 256 {
 257         int err = coda_revalidate_inode(dentry);
 258         if (!err)
 259                 generic_fillattr(dentry->d_inode, stat);
 260         return err;
 261 }
 262
 263 int coda_setattr(struct dentry *de, struct iattr *iattr)
 264 {
 265         struct inode *inode = de->d_inode;
 266         struct coda_vattr vattr;
 267         int error;
 268
 269         memset(&vattr, 0, sizeof(vattr));
 270
 271         inode->i_ctime = CURRENT_TIME_SEC;
 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