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         /*
  89          * Make sure all delayed rcu free inodes are flushed before we
  90          * destroy cache.
  91          */
  92         rcu_barrier();
  93         kmem_cache_destroy(coda_inode_cachep);
  94 }
  95
  96 static int coda_remount(struct super_block *sb, int *flags, char *data)
  97 {
  98         *flags |= MS_NOATIME;
  99         return 0;
 100 }
 101
 102 /* exported operations */
 103 static const struct super_operations coda_super_operations =
 104 {
 105         .alloc_inode    = coda_alloc_inode,
 106         .destroy_inode  = coda_destroy_inode,
 107         .evict_inode    = coda_evict_inode,
 108         .put_super      = coda_put_super,
 109         .statfs         = coda_statfs,
 110         .remount_fs     = coda_remount,
 111 };
 112
 113 static int get_device_index(struct coda_mount_data *data)
 114 {
 115         struct fd f;
 116         struct inode *inode;
 117         int idx;
 118
 119         if (data == NULL) {
 120                 printk("coda_read_super: Bad mount data\n");
 121                 return -1;
 122         }
 123
 124         if (data->version != CODA_MOUNT_VERSION) {
 125                 printk("coda_read_super: Bad mount version\n");
 126                 return -1;
 127         }
 128
 129         f = fdget(data->fd);
 130         if (!f.file)
 131                 goto Ebadf;
 132         inode = f.file->f_path.dentry->d_inode;
 133         if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 134                 fdput(f);
 135                 goto Ebadf;
 136         }
 137
 138         idx = iminor(inode);
 139         fdput(f);
 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 Ebadf:
 148         printk("coda_read_super: Bad file\n");
 149         return -1;
 150 }
 151
 152 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 153 {
 154         struct inode *root = NULL;
 155         struct venus_comm *vc;
 156         struct CodaFid fid;
 157         int error;
 158         int idx;
 159
 160         idx = get_device_index((struct coda_mount_data *) data);
 161
 162         /* Ignore errors in data, for backward compatibility */
 163         if(idx == -1)
 164                 idx = 0;
 165
 166         printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 167
 168         vc = &coda_comms[idx];
 169         mutex_lock(&vc->vc_mutex);
 170
 171         if (!vc->vc_inuse) {
 172                 printk("coda_read_super: No pseudo device\n");
 173                 error = -EINVAL;
 174                 goto unlock_out;
 175         }
 176
 177         if (vc->vc_sb) {
 178                 printk("coda_read_super: Device already mounted\n");
 179                 error = -EBUSY;
 180                 goto unlock_out;
 181         }
 182
 183         error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 184         if (error)
 185                 goto unlock_out;
 186
 187         vc->vc_sb = sb;
 188         mutex_unlock(&vc->vc_mutex);
 189
 190         sb->s_fs_info = vc;
 191         sb->s_flags |= MS_NOATIME;
 192         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 193         sb->s_blocksize_bits = 12;
 194         sb->s_magic = CODA_SUPER_MAGIC;
 195         sb->s_op = &coda_super_operations;
 196         sb->s_d_op = &coda_dentry_operations;
 197         sb->s_bdi = &vc->bdi;
 198
 199         /* get root fid from Venus: this needs the root inode */
 200         error = venus_rootfid(sb, &fid);
 201         if ( error ) {
 202                 printk("coda_read_super: coda_get_rootfid failed with %d\n",
 203                        error);
 204                 goto error;
 205         }
 206         printk("coda_read_super: rootfid is %s\n", 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                 printk("Failure of coda_cnode_make for root: error %d\n", error);
 213                 goto error;
 214         }
 215
 216         printk("coda_read_super: rootinode is %ld dev %s\n",
 217                root->i_ino, root->i_sb->s_id);
 218         sb->s_root = d_make_root(root);
 219         if (!sb->s_root) {
 220                 error = -EINVAL;
 221                 goto error;
 222         }
 223         return 0;
 224
 225 error:
 226         mutex_lock(&vc->vc_mutex);
 227         bdi_destroy(&vc->bdi);
 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         bdi_destroy(&vcp->bdi);
 240         vcp->vc_sb = NULL;
 241         sb->s_fs_info = NULL;
 242         mutex_unlock(&vcp->vc_mutex);
 243
 244         printk("Coda: Bye bye.\n");
 245 }
 246
 247 static void coda_evict_inode(struct inode *inode)
 248 {
 249         truncate_inode_pages(&inode->i_data, 0);
 250         clear_inode(inode);
 251         coda_cache_clear_inode(inode);
 252 }
 253
 254 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 255 {
 256         int err = coda_revalidate_inode(dentry);
 257         if (!err)
 258                 generic_fillattr(dentry->d_inode, stat);
 259         return err;
 260 }
 261
 262 int coda_setattr(struct dentry *de, struct iattr *iattr)
 263 {
 264         struct inode *inode = de->d_inode;
 265         struct coda_vattr vattr;
 266         int error;
 267
 268         memset(&vattr, 0, sizeof(vattr));
 269
 270         inode->i_ctime = CURRENT_TIME_SEC;
 271         coda_iattr_to_vattr(iattr, &vattr);
 272         vattr.va_type = C_VNON; /* cannot set type */
 273
 274         /* Venus is responsible for truncating the container-file!!! */
 275         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 276
 277         if (!error) {
 278                 coda_vattr_to_iattr(inode, &vattr);
 279                 coda_cache_clear_inode(inode);
 280         }
 281         return error;
 282 }
 283
 284 const struct inode_operations coda_file_inode_operations = {
 285         .permission     = coda_permission,
 286         .getattr        = coda_getattr,
 287         .setattr        = coda_setattr,
 288 };
 289
 290 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 291 {
 292         int error;
 293
 294         error = venus_statfs(dentry, buf);
 295
 296         if (error) {
 297                 /* fake something like AFS does */
 298                 buf->f_blocks = 9000000;
 299                 buf->f_bfree  = 9000000;
 300                 buf->f_bavail = 9000000;
 301                 buf->f_files  = 9000000;
 302                 buf->f_ffree  = 9000000;
 303         }
 304
 305         /* and fill in the rest */
 306         buf->f_type = CODA_SUPER_MAGIC;
 307         buf->f_bsize = 4096;
 308         buf->f_namelen = CODA_MAXNAMLEN;
 309
 310         return 0;
 311 }
 312
 313 /* init_coda: used by filesystems.c to register coda */
 314
 315 static struct dentry *coda_mount(struct file_system_type *fs_type,
 316         int flags, const char *dev_name, void *data)
 317 {
 318         return mount_nodev(fs_type, flags, data, coda_fill_super);
 319 }
 320
 321 struct file_system_type coda_fs_type = {
 322         .owner          = THIS_MODULE,
 323         .name           = "coda",
 324         .mount          = coda_mount,
 325         .kill_sb        = kill_anon_super,
 326         .fs_flags       = FS_BINARY_MOUNTDATA,
 327 };
 328