fs/coda/inode.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Super block/filesystem wide operations
   4  *
   5  * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
   6  * Michael Callahan <callahan@maths.ox.ac.uk>
   7  *
   8  * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
   9  * Copyright (C) Carnegie Mellon University
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/mm.h>
  15 #include <linux/string.h>
  16 #include <linux/stat.h>
  17 #include <linux/errno.h>
  18 #include <linux/unistd.h>
  19 #include <linux/mutex.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/file.h>
  22 #include <linux/vfs.h>
  23 #include <linux/slab.h>
  24 #include <linux/pid_namespace.h>
  25 #include <linux/uaccess.h>
  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 = GLOBAL_ROOT_UID;
  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 __init coda_init_inodecache(void)
  76 {
  77         coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  78                                 sizeof(struct coda_inode_info), 0,
  79                                 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
  80                                 SLAB_ACCOUNT, 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         sync_filesystem(sb);
  99         *flags |= SB_NOATIME;
 100         return 0;
 101 }
 102
 103 /* exported operations */
 104 static const struct super_operations coda_super_operations =
 105 {
 106         .alloc_inode    = coda_alloc_inode,
 107         .destroy_inode  = coda_destroy_inode,
 108         .evict_inode    = coda_evict_inode,
 109         .put_super      = coda_put_super,
 110         .statfs         = coda_statfs,
 111         .remount_fs     = coda_remount,
 112 };
 113
 114 static int get_device_index(struct coda_mount_data *data)
 115 {
 116         struct fd f;
 117         struct inode *inode;
 118         int idx;
 119
 120         if (data == NULL) {
 121                 pr_warn("%s: Bad mount data\n", __func__);
 122                 return -1;
 123         }
 124
 125         if (data->version != CODA_MOUNT_VERSION) {
 126                 pr_warn("%s: Bad mount version\n", __func__);
 127                 return -1;
 128         }
 129
 130         f = fdget(data->fd);
 131         if (!f.file)
 132                 goto Ebadf;
 133         inode = file_inode(f.file);
 134         if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 135                 fdput(f);
 136                 goto Ebadf;
 137         }
 138
 139         idx = iminor(inode);
 140         fdput(f);
 141
 142         if (idx < 0 || idx >= MAX_CODADEVS) {
 143                 pr_warn("%s: Bad minor number\n", __func__);
 144                 return -1;
 145         }
 146
 147         return idx;
 148 Ebadf:
 149         pr_warn("%s: Bad file\n", __func__);
 150         return -1;
 151 }
 152
 153 static int coda_fill_super(struct super_block *sb, void *data, int silent)
 154 {
 155         struct inode *root = NULL;
 156         struct venus_comm *vc;
 157         struct CodaFid fid;
 158         int error;
 159         int idx;
 160
 161         if (task_active_pid_ns(current) != &init_pid_ns)
 162                 return -EINVAL;
 163
 164         idx = get_device_index((struct coda_mount_data *) data);
 165
 166         /* Ignore errors in data, for backward compatibility */
 167         if(idx == -1)
 168                 idx = 0;
 169
 170         pr_info("%s: device index: %i\n", __func__,  idx);
 171
 172         vc = &coda_comms[idx];
 173         mutex_lock(&vc->vc_mutex);
 174
 175         if (!vc->vc_inuse) {
 176                 pr_warn("%s: No pseudo device\n", __func__);
 177                 error = -EINVAL;
 178                 goto unlock_out;
 179         }
 180
 181         if (vc->vc_sb) {
 182                 pr_warn("%s: Device already mounted\n", __func__);
 183                 error = -EBUSY;
 184                 goto unlock_out;
 185         }
 186
 187         vc->vc_sb = sb;
 188         mutex_unlock(&vc->vc_mutex);
 189
 190         sb->s_fs_info = vc;
 191         sb->s_flags |= SB_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
 198         error = super_setup_bdi(sb);
 199         if (error)
 200                 goto error;
 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         vc->vc_sb = NULL;
 232         sb->s_fs_info = NULL;
 233 unlock_out:
 234         mutex_unlock(&vc->vc_mutex);
 235         return error;
 236 }
 237
 238 static void coda_put_super(struct super_block *sb)
 239 {
 240         struct venus_comm *vcp = coda_vcp(sb);
 241         mutex_lock(&vcp->vc_mutex);
 242         vcp->vc_sb = NULL;
 243         sb->s_fs_info = NULL;
 244         mutex_unlock(&vcp->vc_mutex);
 245
 246         pr_info("Bye bye.\n");
 247 }
 248
 249 static void coda_evict_inode(struct inode *inode)
 250 {
 251         truncate_inode_pages_final(&inode->i_data);
 252         clear_inode(inode);
 253         coda_cache_clear_inode(inode);
 254 }
 255
 256 int coda_getattr(const struct path *path, struct kstat *stat,
 257                  u32 request_mask, unsigned int flags)
 258 {
 259         int err = coda_revalidate_inode(d_inode(path->dentry));
 260         if (!err)
 261                 generic_fillattr(d_inode(path->dentry), stat);
 262         return err;
 263 }
 264
 265 int coda_setattr(struct dentry *de, struct iattr *iattr)
 266 {
 267         struct inode *inode = d_inode(de);
 268         struct coda_vattr vattr;
 269         int error;
 270
 271         memset(&vattr, 0, sizeof(vattr));
 272
 273         inode->i_ctime = current_time(inode);
 274         coda_iattr_to_vattr(iattr, &vattr);
 275         vattr.va_type = C_VNON; /* cannot set type */
 276
 277         /* Venus is responsible for truncating the container-file!!! */
 278         error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
 279
 280         if (!error) {
 281                 coda_vattr_to_iattr(inode, &vattr);
 282                 coda_cache_clear_inode(inode);
 283         }
 284         return error;
 285 }
 286
 287 const struct inode_operations coda_file_inode_operations = {
 288         .permission     = coda_permission,
 289         .getattr        = coda_getattr,
 290         .setattr        = coda_setattr,
 291 };
 292
 293 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
 294 {
 295         int error;
 296
 297         error = venus_statfs(dentry, buf);
 298
 299         if (error) {
 300                 /* fake something like AFS does */
 301                 buf->f_blocks = 9000000;
 302                 buf->f_bfree  = 9000000;
 303                 buf->f_bavail = 9000000;
 304                 buf->f_files  = 9000000;
 305                 buf->f_ffree  = 9000000;
 306         }
 307
 308         /* and fill in the rest */
 309         buf->f_type = CODA_SUPER_MAGIC;
 310         buf->f_bsize = 4096;
 311         buf->f_namelen = CODA_MAXNAMLEN;
 312
 313         return 0;
 314 }
 315
 316 /* init_coda: used by filesystems.c to register coda */
 317
 318 static struct dentry *coda_mount(struct file_system_type *fs_type,
 319         int flags, const char *dev_name, void *data)
 320 {
 321         return mount_nodev(fs_type, flags, data, coda_fill_super);
 322 }
 323
 324 struct file_system_type coda_fs_type = {
 325         .owner          = THIS_MODULE,
 326         .name           = "coda",
 327         .mount          = coda_mount,
 328         .kill_sb        = kill_anon_super,
 329         .fs_flags       = FS_BINARY_MOUNTDATA,
 330 };
 331 MODULE_ALIAS_FS("coda");
 332