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         kmem_cache_free(coda_inode_cachep, ITOC(inode));
  62 }
  63
  64 static void coda_destroy_inode(struct inode *inode)
  65 {
  66         call_rcu(&inode->i_rcu, coda_i_callback);
  67 }
  68
  69 static void init_once(void *foo)
  70 {
  71         struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  72
  73         inode_init_once(&ei->vfs_inode);
  74 }
  75
  76 int coda_init_inodecache(void)
  77 {
  78         coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  79                                 sizeof(struct coda_inode_info),
  80                                 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  81                                 init_once);
  82         if (coda_inode_cachep == NULL)
  83                 return -ENOMEM;
  84         return 0;
  85 }
  86
  87 void coda_destroy_inodecache(void)
  88 {
  89         kmem_cache_destroy(coda_inode_cachep);
  90 }
  91
  92 static int coda_remount(struct super_block *sb, int *flags, char *data)
  93 {
  94         *flags |= MS_NOATIME;
  95         return 0;
  96 }
  97
  98 /* exported operations */
  99 static const struct super_operations coda_super_operations =
 100 {
 101         .alloc_inode    = coda_alloc_inode,
 102         .destroy_inode  = coda_destroy_inode,
 103         .evict_inode    = coda_evict_inode,
 104         .put_super      = coda_put_super,
 105         .statfs         = coda_statfs,
 106         .remount_fs     = coda_remount,
 107 };
 108
 109 static int get_device_index(struct coda_mount_data *data)
 110 {
 111         struct file *file;
 112         struct inode *inode;
 113         int idx;
 114
 115         if(data == NULL) {
 116                 printk("coda_read_super: Bad mount data\n");
 117                 return -1;
 118         }
 119
 120         if(data->version != CODA_MOUNT_VERSION) {
 121                 printk("coda_read_super: Bad mount version\n");
 122                 return -1;
 123         }
 124
 125         file = fget(data->fd);
 126         inode = NULL;
 127         if(file)
 128                 inode = file->f_path.dentry->d_inode;
 129
 130         if(!inode || !S_ISCHR(inode->i_mode) ||
 131            imajor(inode) != CODA_PSDEV_MAJOR) {
 132                 if(file)
 133                         fput(file);
 134
 135                 printk("coda_read_super: Bad file\n");
 136                 return -1;
 137         }
 138
 139         idx = iminor(inode);
 140         fput(file);
 141
 142         if(idx < 0 || idx >= MAX_CODADEVS) {
 143                 printk("coda_read_super: Bad minor number\n");
 144                 return -1;
 145         }
 146
 147         return idx;
 148 }
 149
 150 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 151 {
 152         struct inode *root = NULL;
 153         struct venus_comm *vc;
 154         struct CodaFid fid;
 155         int error;
 156         int idx;
 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         printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 165
 166         vc = &coda_comms[idx];
 167         mutex_lock(&vc->vc_mutex);
 168
 169         if (!vc->vc_inuse) {
 170                 printk("coda_read_super: No pseudo device\n");
 171                 error = -EINVAL;
 172                 goto unlock_out;
 173         }
 174
 175         if (vc->vc_sb) {
 176                 printk("coda_read_super: Device already mounted\n");
 177                 error = -EBUSY;
 178                 goto unlock_out;
 179         }
 180
 181         error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 182         if (error)
 183                 goto unlock_out;
 184
 185         vc->vc_sb = sb;
 186         mutex_unlock(&vc->vc_mutex);
 187
 188         sb->s_fs_info = vc;
 189         sb->s_flags |= MS_NOATIME;
 190         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 191         sb->s_blocksize_bits = 12;
 192         sb->s_magic = CODA_SUPER_MAGIC;
 193         sb->s_op = &coda_super_operations;
 194         sb->s_d_op = &coda_dentry_operations;
 195         sb->s_bdi = &vc->bdi;
 196
 197         /* get root fid from Venus: this needs the root inode */
 198         error = venus_rootfid(sb, &fid);
 199         if ( error ) {
 200                 printk("coda_read_super: coda_get_rootfid failed with %d\n",
 201                        error);
 202                 goto error;
 203         }
 204         printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 205
 206         /* make root inode */
 207         root = coda_cnode_make(&fid, sb);
 208         if (IS_ERR(root)) {
 209                 error = PTR_ERR(root);
 210                 printk("Failure of coda_cnode_make for root: error %d\n", error);
 211                 root = NULL;
 212                 goto error;
 213         }
 214
 215         printk("coda_read_super: rootinode is %ld dev %s\n",
 216                root->i_ino, root->i_sb->s_id);
 217         sb->s_root = d_alloc_root(root);
 218         if (!sb->s_root) {
 219                 error = -EINVAL;
 220                 goto error;
 221         }
 222         return 0;
 223
 224 error:
 225         if (root)
 226                 iput(root);
 227
 228         mutex_lock(&vc->vc_mutex);
 229         bdi_destroy(&vc->bdi);
 230         vc->vc_sb = NULL;
 231         sb->s_fs_info = NULL;
 232 unlock_out:
 233         mutex_unlock(&vc->vc_mutex);
 234         return error;
 235 }
 236
 237 static void coda_put_super(struct super_block *sb)
 238 {
 239         struct venus_comm *vcp = coda_vcp(sb);
 240         mutex_lock(&vcp->vc_mutex);
 241         bdi_destroy(&vcp->bdi);
 242         vcp->vc_sb = NULL;
 243         sb->s_fs_info = NULL;
 244         mutex_unlock(&vcp->vc_mutex);
 245
 246         printk("Coda: Bye bye.\n");
 247 }
 248
 249 static void coda_evict_inode(struct inode *inode)
 250 {
 251         truncate_inode_pages(&inode->i_data, 0);
 252         end_writeback(inode);
 253         coda_cache_clear_inode(inode);
 254 }
 255
 256 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 257 {
 258         int err = coda_revalidate_inode(dentry);
 259         if (!err)
 260                 generic_fillattr(dentry->d_inode, stat);
 261         return err;
 262 }
 263
 264 int coda_setattr(struct dentry *de, struct iattr *iattr)
 265 {
 266         struct inode *inode = de->d_inode;
 267         struct coda_vattr vattr;
 268         int error;
 269
 270         memset(&vattr, 0, sizeof(vattr));
 271
 272         inode->i_ctime = CURRENT_TIME_SEC;
 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
 286 const struct inode_operations coda_file_inode_operations = {
 287         .permission     = coda_permission,
 288         .getattr        = coda_getattr,
 289         .setattr        = coda_setattr,
 290 };
 291
 292 static 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
 317 static 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
 323 struct 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 };
 330