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/uaccess.h>
  25
  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 */
  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 = 0;
  52         ei->c_cached_perm = 0;
  53         spin_lock_init(&ei->c_lock);
  54         return &ei->vfs_inode;
  55 }
  56
  57 static 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
  63 static void coda_destroy_inode(struct inode *inode)
  64 {
  65         call_rcu(&inode->i_rcu, coda_i_callback);
  66 }
  67
  68 static 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
  75 int coda_init_inodecache(void)
  76 {
  77         coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  78                                 sizeof(struct coda_inode_info),
  79                                 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  80                                 init_once);
  81         if (coda_inode_cachep == NULL)
  82                 return -ENOMEM;
  83         return 0;
  84 }
  85
  86 void coda_destroy_inodecache(void)
  87 {
  88         kmem_cache_destroy(coda_inode_cachep);
  89 }
  90
  91 static int coda_remount(struct super_block *sb, int *flags, char *data)
  92 {
  93         *flags |= MS_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         .destroy_inode  = coda_destroy_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 file *file;
 111         struct inode *inode;
 112         int idx;
 113
 114         if(data == NULL) {
 115                 printk("coda_read_super: Bad mount data\n");
 116                 return -1;
 117         }
 118
 119         if(data->version != CODA_MOUNT_VERSION) {
 120                 printk("coda_read_super: Bad mount version\n");
 121                 return -1;
 122         }
 123
 124         file = fget(data->fd);
 125         inode = NULL;
 126         if(file)
 127                 inode = file->f_path.dentry->d_inode;
 128
 129         if(!inode || !S_ISCHR(inode->i_mode) ||
 130            imajor(inode) != CODA_PSDEV_MAJOR) {
 131                 if(file)
 132                         fput(file);
 133
 134                 printk("coda_read_super: Bad file\n");
 135                 return -1;
 136         }
 137
 138         idx = iminor(inode);
 139         fput(file);
 140
 141         if(idx < 0 || idx >= MAX_CODADEVS) {
 142                 printk("coda_read_super: Bad minor number\n");
 143                 return -1;
 144         }
 145
 146         return idx;
 147 }
 148
 149 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 150 {
 151         struct inode *root = NULL;
 152         struct venus_comm *vc;
 153         struct CodaFid fid;
 154         int error;
 155         int idx;
 156
 157         idx = get_device_index((struct coda_mount_data *) data);
 158
 159         /* Ignore errors in data, for backward compatibility */
 160         if(idx == -1)
 161                 idx = 0;
 162
 163         printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 164
 165         vc = &coda_comms[idx];
 166         mutex_lock(&vc->vc_mutex);
 167
 168         if (!vc->vc_inuse) {
 169                 printk("coda_read_super: No pseudo device\n");
 170                 error = -EINVAL;
 171                 goto unlock_out;
 172         }
 173
 174         if (vc->vc_sb) {
 175                 printk("coda_read_super: Device already mounted\n");
 176                 error = -EBUSY;
 177                 goto unlock_out;
 178         }
 179
 180         error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 181         if (error)
 182                 goto unlock_out;
 183
 184         vc->vc_sb = sb;
 185         mutex_unlock(&vc->vc_mutex);
 186
 187         sb->s_fs_info = vc;
 188         sb->s_flags |= MS_NOATIME;
 189         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 190         sb->s_blocksize_bits = 12;
 191         sb->s_magic = CODA_SUPER_MAGIC;
 192         sb->s_op = &coda_super_operations;
 193         sb->s_d_op = &coda_dentry_operations;
 194         sb->s_bdi = &vc->bdi;
 195
 196         /* get root fid from Venus: this needs the root inode */
 197         error = venus_rootfid(sb, &fid);
 198         if ( error ) {
 199                 printk("coda_read_super: coda_get_rootfid failed with %d\n",
 200                        error);
 201                 goto error;
 202         }
 203         printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 204
 205         /* make root inode */
 206         root = coda_cnode_make(&fid, sb);
 207         if (IS_ERR(root)) {
 208                 error = PTR_ERR(root);
 209                 printk("Failure of coda_cnode_make for root: error %d\n", error);
 210                 goto error;
 211         }
 212
 213         printk("coda_read_super: rootinode is %ld dev %s\n",
 214                root->i_ino, root->i_sb->s_id);
 215         sb->s_root = d_make_root(root);
 216         if (!sb->s_root) {
 217                 error = -EINVAL;
 218                 goto error;
 219         }
 220         return 0;
 221
 222 error:
 223         mutex_lock(&vc->vc_mutex);
 224         bdi_destroy(&vc->bdi);
 225         vc->vc_sb = NULL;
 226         sb->s_fs_info = NULL;
 227 unlock_out:
 228         mutex_unlock(&vc->vc_mutex);
 229         return error;
 230 }
 231
 232 static void coda_put_super(struct super_block *sb)
 233 {
 234         struct venus_comm *vcp = coda_vcp(sb);
 235         mutex_lock(&vcp->vc_mutex);
 236         bdi_destroy(&vcp->bdi);
 237         vcp->vc_sb = NULL;
 238         sb->s_fs_info = NULL;
 239         mutex_unlock(&vcp->vc_mutex);
 240
 241         printk("Coda: Bye bye.\n");
 242 }
 243
 244 static void coda_evict_inode(struct inode *inode)
 245 {
 246         truncate_inode_pages(&inode->i_data, 0);
 247         end_writeback(inode);
 248         coda_cache_clear_inode(inode);
 249 }
 250
 251 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 252 {
 253         int err = coda_revalidate_inode(dentry);
 254         if (!err)
 255                 generic_fillattr(dentry->d_inode, stat);
 256         return err;
 257 }
 258
 259 int coda_setattr(struct dentry *de, struct iattr *iattr)
 260 {
 261         struct inode *inode = de->d_inode;
 262         struct coda_vattr vattr;
 263         int error;
 264
 265         memset(&vattr, 0, sizeof(vattr));
 266
 267         inode->i_ctime = CURRENT_TIME_SEC;
 268         coda_iattr_to_vattr(iattr, &vattr);
 269         vattr.va_type = C_VNON; /* cannot set type */
 270
 271         /* Venus is responsible for truncating the container-file!!! */
 272         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 273
 274         if (!error) {
 275                 coda_vattr_to_iattr(inode, &vattr);
 276                 coda_cache_clear_inode(inode);
 277         }
 278         return error;
 279 }
 280
 281 const struct inode_operations coda_file_inode_operations = {
 282         .permission     = coda_permission,
 283         .getattr        = coda_getattr,
 284         .setattr        = coda_setattr,
 285 };
 286
 287 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 288 {
 289         int error;
 290
 291         error = venus_statfs(dentry, buf);
 292
 293         if (error) {
 294                 /* fake something like AFS does */
 295                 buf->f_blocks = 9000000;
 296                 buf->f_bfree  = 9000000;
 297                 buf->f_bavail = 9000000;
 298                 buf->f_files  = 9000000;
 299                 buf->f_ffree  = 9000000;
 300         }
 301
 302         /* and fill in the rest */
 303         buf->f_type = CODA_SUPER_MAGIC;
 304         buf->f_bsize = 4096;
 305         buf->f_namelen = CODA_MAXNAMLEN;
 306
 307         return 0;
 308 }
 309
 310 /* init_coda: used by filesystems.c to register coda */
 311
 312 static struct dentry *coda_mount(struct file_system_type *fs_type,
 313         int flags, const char *dev_name, void *data)
 314 {
 315         return mount_nodev(fs_type, flags, data, coda_fill_super);
 316 }
 317
 318 struct file_system_type coda_fs_type = {
 319         .owner          = THIS_MODULE,
 320         .name           = "coda",
 321         .mount          = coda_mount,
 322         .kill_sb        = kill_anon_super,
 323         .fs_flags       = FS_BINARY_MOUNTDATA,
 324 };
 325