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 #include <linux/uaccess.h>
  25 #include <linux/fs.h>
  26 #include <linux/vmalloc.h>
  27
  28 #include <linux/coda.h>
  29 #include <linux/coda_psdev.h>
  30 #include "coda_linux.h"
  31 #include "coda_cache.h"
  32
  33 #include "coda_int.h"
  34
  35 /* VFS super_block ops */
  36 static void coda_evict_inode(struct inode *);
  37 static void coda_put_super(struct super_block *);
  38 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  39
  40 static struct kmem_cache * coda_inode_cachep;
  41
  42 static struct inode *coda_alloc_inode(struct super_block *sb)
  43 {
  44         struct coda_inode_info *ei;
  45         ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
  46         if (!ei)
  47                 return NULL;
  48         memset(&ei->c_fid, 0, sizeof(struct CodaFid));
  49         ei->c_flags = 0;
  50         ei->c_uid = GLOBAL_ROOT_UID;
  51         ei->c_cached_perm = 0;
  52         spin_lock_init(&ei->c_lock);
  53         return &ei->vfs_inode;
  54 }
  55
  56 static void coda_i_callback(struct rcu_head *head)
  57 {
  58         struct inode *inode = container_of(head, struct inode, i_rcu);
  59         kmem_cache_free(coda_inode_cachep, ITOC(inode));
  60 }
  61
  62 static void coda_destroy_inode(struct inode *inode)
  63 {
  64         call_rcu(&inode->i_rcu, coda_i_callback);
  65 }
  66
  67 static void init_once(void *foo)
  68 {
  69         struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  70
  71         inode_init_once(&ei->vfs_inode);
  72 }
  73
  74 int __init coda_init_inodecache(void)
  75 {
  76         coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  77                                 sizeof(struct coda_inode_info), 0,
  78                                 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
  79                                 SLAB_ACCOUNT, init_once);
  80         if (coda_inode_cachep == NULL)
  81                 return -ENOMEM;
  82         return 0;
  83 }
  84
  85 void coda_destroy_inodecache(void)
  86 {
  87         /*
  88          * Make sure all delayed rcu free inodes are flushed before we
  89          * destroy cache.
  90          */
  91         rcu_barrier();
  92         kmem_cache_destroy(coda_inode_cachep);
  93 }
  94
  95 static int coda_remount(struct super_block *sb, int *flags, char *data)
  96 {
  97         sync_filesystem(sb);
  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                 pr_warn("%s: Bad mount data\n", __func__);
 121                 return -1;
 122         }
 123
 124         if (data->version != CODA_MOUNT_VERSION) {
 125                 pr_warn("%s: Bad mount version\n", __func__);
 126                 return -1;
 127         }
 128
 129         f = fdget(data->fd);
 130         if (!f.file)
 131                 goto Ebadf;
 132         inode = file_inode(f.file);
 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                 pr_warn("%s: Bad minor number\n", __func__);
 143                 return -1;
 144         }
 145
 146         return idx;
 147 Ebadf:
 148         pr_warn("%s: Bad file\n", __func__);
 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         if (task_active_pid_ns(current) != &init_pid_ns)
 161                 return -EINVAL;
 162
 163         idx = get_device_index((struct coda_mount_data *) data);
 164
 165         /* Ignore errors in data, for backward compatibility */
 166         if(idx == -1)
 167                 idx = 0;
 168
 169         pr_info("%s: device index: %i\n", __func__,  idx);
 170
 171         vc = &coda_comms[idx];
 172         mutex_lock(&vc->vc_mutex);
 173
 174         if (!vc->vc_inuse) {
 175                 pr_warn("%s: No pseudo device\n", __func__);
 176                 error = -EINVAL;
 177                 goto unlock_out;
 178         }
 179
 180         if (vc->vc_sb) {
 181                 pr_warn("%s: Device already mounted\n", __func__);
 182                 error = -EBUSY;
 183                 goto unlock_out;
 184         }
 185
 186         error = bdi_setup_and_register(&vc->bdi, "coda");
 187         if (error)
 188                 goto unlock_out;
 189
 190         vc->vc_sb = sb;
 191         mutex_unlock(&vc->vc_mutex);
 192
 193         sb->s_fs_info = vc;
 194         sb->s_flags |= MS_NOATIME;
 195         sb->s_blocksize = 4096; /* XXXXX  what do we put here?? */
 196         sb->s_blocksize_bits = 12;
 197         sb->s_magic = CODA_SUPER_MAGIC;
 198         sb->s_op = &coda_super_operations;
 199         sb->s_d_op = &coda_dentry_operations;
 200         sb->s_bdi = &vc->bdi;
 201
 202         /* get root fid from Venus: this needs the root inode */
 203         error = venus_rootfid(sb, &fid);
 204         if ( error ) {
 205                 pr_warn("%s: coda_get_rootfid failed with %d\n",
 206                         __func__, error);
 207                 goto error;
 208         }
 209         pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
 210
 211         /* make root inode */
 212         root = coda_cnode_make(&fid, sb);
 213         if (IS_ERR(root)) {
 214                 error = PTR_ERR(root);
 215                 pr_warn("Failure of coda_cnode_make for root: error %d\n",
 216                         error);
 217                 goto error;
 218         }
 219
 220         pr_info("%s: rootinode is %ld dev %s\n",
 221                 __func__, root->i_ino, root->i_sb->s_id);
 222         sb->s_root = d_make_root(root);
 223         if (!sb->s_root) {
 224                 error = -EINVAL;
 225                 goto error;
 226         }
 227         return 0;
 228
 229 error:
 230         mutex_lock(&vc->vc_mutex);
 231         bdi_destroy(&vc->bdi);
 232         vc->vc_sb = NULL;
 233         sb->s_fs_info = NULL;
 234 unlock_out:
 235         mutex_unlock(&vc->vc_mutex);
 236         return error;
 237 }
 238
 239 static void coda_put_super(struct super_block *sb)
 240 {
 241         struct venus_comm *vcp = coda_vcp(sb);
 242         mutex_lock(&vcp->vc_mutex);
 243         bdi_destroy(&vcp->bdi);
 244         vcp->vc_sb = NULL;
 245         sb->s_fs_info = NULL;
 246         mutex_unlock(&vcp->vc_mutex);
 247
 248         pr_info("Bye bye.\n");
 249 }
 250
 251 static void coda_evict_inode(struct inode *inode)
 252 {
 253         truncate_inode_pages_final(&inode->i_data);
 254         clear_inode(inode);
 255         coda_cache_clear_inode(inode);
 256 }
 257
 258 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 259 {
 260         int err = coda_revalidate_inode(d_inode(dentry));
 261         if (!err)
 262                 generic_fillattr(d_inode(dentry), stat);
 263         return err;
 264 }
 265
 266 int coda_setattr(struct dentry *de, struct iattr *iattr)
 267 {
 268         struct inode *inode = d_inode(de);
 269         struct coda_vattr vattr;
 270         int error;
 271
 272         memset(&vattr, 0, sizeof(vattr));
 273
 274         inode->i_ctime = CURRENT_TIME_SEC;
 275         coda_iattr_to_vattr(iattr, &vattr);
 276         vattr.va_type = C_VNON; /* cannot set type */
 277
 278         /* Venus is responsible for truncating the container-file!!! */
 279         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 280
 281         if (!error) {
 282                 coda_vattr_to_iattr(inode, &vattr);
 283                 coda_cache_clear_inode(inode);
 284         }
 285         return error;
 286 }
 287
 288 const struct inode_operations coda_file_inode_operations = {
 289         .permission     = coda_permission,
 290         .getattr        = coda_getattr,
 291         .setattr        = coda_setattr,
 292 };
 293
 294 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 295 {
 296         int error;
 297
 298         error = venus_statfs(dentry, buf);
 299
 300         if (error) {
 301                 /* fake something like AFS does */
 302                 buf->f_blocks = 9000000;
 303                 buf->f_bfree  = 9000000;
 304                 buf->f_bavail = 9000000;
 305                 buf->f_files  = 9000000;
 306                 buf->f_ffree  = 9000000;
 307         }
 308
 309         /* and fill in the rest */
 310         buf->f_type = CODA_SUPER_MAGIC;
 311         buf->f_bsize = 4096;
 312         buf->f_namelen = CODA_MAXNAMLEN;
 313
 314         return 0;
 315 }
 316
 317 /* init_coda: used by filesystems.c to register coda */
 318
 319 static struct dentry *coda_mount(struct file_system_type *fs_type,
 320         int flags, const char *dev_name, void *data)
 321 {
 322         return mount_nodev(fs_type, flags, data, coda_fill_super);
 323 }
 324
 325 struct file_system_type coda_fs_type = {
 326         .owner          = THIS_MODULE,
 327         .name           = "coda",
 328         .mount          = coda_mount,
 329         .kill_sb        = kill_anon_super,
 330         .fs_flags       = FS_BINARY_MOUNTDATA,
 331 };
 332 MODULE_ALIAS_FS("coda");
 333