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 #include <linux/pid_namespace.h>
  24
  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 = GLOBAL_ROOT_UID;
  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 __init 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         /*
  90          * Make sure all delayed rcu free inodes are flushed before we
  91          * destroy cache.
  92          */
  93         rcu_barrier();
  94         kmem_cache_destroy(coda_inode_cachep);
  95 }
  96
  97 static int coda_remount(struct super_block *sb, int *flags, char *data)
  98 {
  99         sync_filesystem(sb);
 100         *flags |= MS_NOATIME;
 101         return 0;
 102 }
 103
 104 /* exported operations */
 105 static const struct super_operations coda_super_operations =
 106 {
 107         .alloc_inode    = coda_alloc_inode,
 108         .destroy_inode  = coda_destroy_inode,
 109         .evict_inode    = coda_evict_inode,
 110         .put_super      = coda_put_super,
 111         .statfs         = coda_statfs,
 112         .remount_fs     = coda_remount,
 113 };
 114
 115 static int get_device_index(struct coda_mount_data *data)
 116 {
 117         struct fd f;
 118         struct inode *inode;
 119         int idx;
 120
 121         if (data == NULL) {
 122                 printk("coda_read_super: Bad mount data\n");
 123                 return -1;
 124         }
 125
 126         if (data->version != CODA_MOUNT_VERSION) {
 127                 printk("coda_read_super: Bad mount version\n");
 128                 return -1;
 129         }
 130
 131         f = fdget(data->fd);
 132         if (!f.file)
 133                 goto Ebadf;
 134         inode = file_inode(f.file);
 135         if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 136                 fdput(f);
 137                 goto Ebadf;
 138         }
 139
 140         idx = iminor(inode);
 141         fdput(f);
 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 Ebadf:
 150         printk("coda_read_super: Bad file\n");
 151         return -1;
 152 }
 153
 154 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 155 {
 156         struct inode *root = NULL;
 157         struct venus_comm *vc;
 158         struct CodaFid fid;
 159         int error;
 160         int idx;
 161
 162         if (task_active_pid_ns(current) != &init_pid_ns)
 163                 return -EINVAL;
 164
 165         idx = get_device_index((struct coda_mount_data *) data);
 166
 167         /* Ignore errors in data, for backward compatibility */
 168         if(idx == -1)
 169                 idx = 0;
 170
 171         printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
 172
 173         vc = &coda_comms[idx];
 174         mutex_lock(&vc->vc_mutex);
 175
 176         if (!vc->vc_inuse) {
 177                 printk("coda_read_super: No pseudo device\n");
 178                 error = -EINVAL;
 179                 goto unlock_out;
 180         }
 181
 182         if (vc->vc_sb) {
 183                 printk("coda_read_super: Device already mounted\n");
 184                 error = -EBUSY;
 185                 goto unlock_out;
 186         }
 187
 188         error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
 189         if (error)
 190                 goto unlock_out;
 191
 192         vc->vc_sb = sb;
 193         mutex_unlock(&vc->vc_mutex);
 194
 195         sb->s_fs_info = vc;
 196         sb->s_flags |= MS_NOATIME;
 197         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 198         sb->s_blocksize_bits = 12;
 199         sb->s_magic = CODA_SUPER_MAGIC;
 200         sb->s_op = &coda_super_operations;
 201         sb->s_d_op = &coda_dentry_operations;
 202         sb->s_bdi = &vc->bdi;
 203
 204         /* get root fid from Venus: this needs the root inode */
 205         error = venus_rootfid(sb, &fid);
 206         if ( error ) {
 207                 printk("coda_read_super: coda_get_rootfid failed with %d\n",
 208                        error);
 209                 goto error;
 210         }
 211         printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
 212
 213         /* make root inode */
 214         root = coda_cnode_make(&fid, sb);
 215         if (IS_ERR(root)) {
 216                 error = PTR_ERR(root);
 217                 printk("Failure of coda_cnode_make for root: error %d\n", error);
 218                 goto error;
 219         }
 220
 221         printk("coda_read_super: rootinode is %ld dev %s\n",
 222                root->i_ino, root->i_sb->s_id);
 223         sb->s_root = d_make_root(root);
 224         if (!sb->s_root) {
 225                 error = -EINVAL;
 226                 goto error;
 227         }
 228         return 0;
 229
 230 error:
 231         mutex_lock(&vc->vc_mutex);
 232         bdi_destroy(&vc->bdi);
 233         vc->vc_sb = NULL;
 234         sb->s_fs_info = NULL;
 235 unlock_out:
 236         mutex_unlock(&vc->vc_mutex);
 237         return error;
 238 }
 239
 240 static void coda_put_super(struct super_block *sb)
 241 {
 242         struct venus_comm *vcp = coda_vcp(sb);
 243         mutex_lock(&vcp->vc_mutex);
 244         bdi_destroy(&vcp->bdi);
 245         vcp->vc_sb = NULL;
 246         sb->s_fs_info = NULL;
 247         mutex_unlock(&vcp->vc_mutex);
 248
 249         printk("Coda: Bye bye.\n");
 250 }
 251
 252 static void coda_evict_inode(struct inode *inode)
 253 {
 254         truncate_inode_pages_final(&inode->i_data);
 255         clear_inode(inode);
 256         coda_cache_clear_inode(inode);
 257 }
 258
 259 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 260 {
 261         int err = coda_revalidate_inode(dentry->d_inode);
 262         if (!err)
 263                 generic_fillattr(dentry->d_inode, stat);
 264         return err;
 265 }
 266
 267 int coda_setattr(struct dentry *de, struct iattr *iattr)
 268 {
 269         struct inode *inode = de->d_inode;
 270         struct coda_vattr vattr;
 271         int error;
 272
 273         memset(&vattr, 0, sizeof(vattr));
 274
 275         inode->i_ctime = CURRENT_TIME_SEC;
 276         coda_iattr_to_vattr(iattr, &vattr);
 277         vattr.va_type = C_VNON; /* cannot set type */
 278
 279         /* Venus is responsible for truncating the container-file!!! */
 280         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 281
 282         if (!error) {
 283                 coda_vattr_to_iattr(inode, &vattr);
 284                 coda_cache_clear_inode(inode);
 285         }
 286         return error;
 287 }
 288
 289 const struct inode_operations coda_file_inode_operations = {
 290         .permission     = coda_permission,
 291         .getattr        = coda_getattr,
 292         .setattr        = coda_setattr,
 293 };
 294
 295 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 296 {
 297         int error;
 298
 299         error = venus_statfs(dentry, buf);
 300
 301         if (error) {
 302                 /* fake something like AFS does */
 303                 buf->f_blocks = 9000000;
 304                 buf->f_bfree  = 9000000;
 305                 buf->f_bavail = 9000000;
 306                 buf->f_files  = 9000000;
 307                 buf->f_ffree  = 9000000;
 308         }
 309
 310         /* and fill in the rest */
 311         buf->f_type = CODA_SUPER_MAGIC;
 312         buf->f_bsize = 4096;
 313         buf->f_namelen = CODA_MAXNAMLEN;
 314
 315         return 0;
 316 }
 317
 318 /* init_coda: used by filesystems.c to register coda */
 319
 320 static struct dentry *coda_mount(struct file_system_type *fs_type,
 321         int flags, const char *dev_name, void *data)
 322 {
 323         return mount_nodev(fs_type, flags, data, coda_fill_super);
 324 }
 325
 326 struct file_system_type coda_fs_type = {
 327         .owner          = THIS_MODULE,
 328         .name           = "coda",
 329         .mount          = coda_mount,
 330         .kill_sb        = kill_anon_super,
 331         .fs_flags       = FS_BINARY_MOUNTDATA,
 332 };
 333 MODULE_ALIAS_FS("coda");
 334