src/afs/LINUX/osi_vfsops.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * VFS operations for Linux
  12  *
  13  * super_block operations should return negated errno to Linux.
  14  */
  15 #include <afsconfig.h>
  16 #include "afs/param.h"
  17
  18
  19 #define __NO_VERSION__          /* don't define kernel_version in module.h */
  20 #include <linux/module.h> /* early to avoid printf->printk mapping */
  21 #include "afs/sysincludes.h"
  22 #include "afsincludes.h"
  23 #include "afs/afs_stats.h"
  24
  25 #include "osi_compat.h"
  26
  27 struct vcache *afs_globalVp = 0;
  28 struct vfs *afs_globalVFS = 0;
  29 struct vfsmount *afs_cacheMnt;
  30 int afs_was_mounted = 0;        /* Used to force reload if mount/unmount/mount */
  31
  32 extern struct super_operations afs_sops;
  33 #if !defined(AFS_NONFSTRANS)
  34 extern struct export_operations afs_export_ops;
  35 #endif
  36 extern afs_rwlock_t afs_xvcache;
  37 extern struct afs_q VLRU;
  38
  39 extern struct dentry_operations afs_dentry_operations;
  40
  41 /* Forward declarations */
  42 static int afs_root(struct super_block *afsp);
  43 int afs_fill_super(struct super_block *sb, void *data, int silent);
  44
  45
  46 /*
  47  * afs_mount (2.6.37+) and afs_get_sb (2.6.36-) are the entry
  48  * points from the vfs when mounting afs.  The super block
  49  * structure is setup in the afs_fill_super callback function.
  50  */
  51
  52 #if defined(STRUCT_FILE_SYSTEM_TYPE_HAS_MOUNT)
  53 static struct dentry *
  54 afs_mount(struct file_system_type *fs_type, int flags,
  55            const char *dev_name, void *data) {
  56     return mount_nodev(fs_type, flags, data, afs_fill_super);
  57 }
  58 #elif defined(GET_SB_HAS_STRUCT_VFSMOUNT)
  59 static int
  60 afs_get_sb(struct file_system_type *fs_type, int flags,
  61            const char *dev_name, void *data, struct vfsmount *mnt) {
  62     return get_sb_nodev(fs_type, flags, data, afs_fill_super, mnt);
  63 }
  64 #else
  65 static struct super_block *
  66 afs_get_sb(struct file_system_type *fs_type, int flags,
  67            const char *dev_name, void *data) {
  68     return get_sb_nodev(fs_type, flags, data, afs_fill_super);
  69 }
  70 #endif
  71
  72 struct file_system_type afs_fs_type = {
  73     .owner = THIS_MODULE,
  74     .name = "afs",
  75 #if defined(STRUCT_FILE_SYSTEM_TYPE_HAS_MOUNT)
  76     .mount = afs_mount,
  77 #else
  78     .get_sb = afs_get_sb,
  79 #endif
  80     .kill_sb = kill_anon_super,
  81     .fs_flags = FS_BINARY_MOUNTDATA,
  82 };
  83
  84 struct backing_dev_info *afs_backing_dev_info;
  85
  86 int
  87 afs_fill_super(struct super_block *sb, void *data, int silent)
  88 {
  89     int code = 0;
  90 #if defined(HAVE_LINUX_BDI_INIT)
  91     int bdi_init_done = 0;
  92 #endif
  93
  94     AFS_GLOCK();
  95     if (afs_was_mounted) {
  96         printf
  97             ("You must reload the AFS kernel extensions before remounting AFS.\n");
  98         AFS_GUNLOCK();
  99         return -EINVAL;
 100     }
 101     afs_was_mounted = 1;
 102
 103     /* Set basics of super_block */
 104    __module_get(THIS_MODULE);
 105
 106     afs_globalVFS = sb;
 107 #if defined(SB_NOATIME)
 108     sb->s_flags |= SB_NOATIME;
 109 #else
 110     sb->s_flags |= MS_NOATIME;
 111 #endif
 112     sb->s_blocksize = 1024;
 113     sb->s_blocksize_bits = 10;
 114     sb->s_magic = AFS_VFSMAGIC;
 115     sb->s_op = &afs_sops;       /* Super block (vfs) ops */
 116
 117 #if defined(STRUCT_SUPER_BLOCK_HAS_S_D_OP)
 118     sb->s_d_op = &afs_dentry_operations;
 119 #endif
 120 #if defined(HAVE_LINUX_SUPER_SETUP_BDI)
 121     code = super_setup_bdi(sb);
 122     if (code)
 123         goto out;
 124     sb->s_bdi->name = "openafs";
 125     sb->s_bdi->ra_pages = 32;
 126 #else
 127     /* used for inodes backing_dev_info field, also */
 128     afs_backing_dev_info = kzalloc(sizeof(struct backing_dev_info), GFP_NOFS);
 129 #if defined(HAVE_LINUX_BDI_INIT)
 130     code = bdi_init(afs_backing_dev_info);
 131     if (code)
 132         goto out;
 133     bdi_init_done = 1;
 134 #endif
 135 #if defined(STRUCT_BACKING_DEV_INFO_HAS_NAME)
 136     afs_backing_dev_info->name = "openafs";
 137 #endif
 138     afs_backing_dev_info->ra_pages = 32;
 139 #if defined (STRUCT_SUPER_BLOCK_HAS_S_BDI)
 140     sb->s_bdi = afs_backing_dev_info;
 141     /* The name specified here will appear in the flushing thread name - flush-afs */
 142     bdi_register(afs_backing_dev_info, NULL, "afs");
 143 #endif
 144 #endif /* HAVE_LINUX_SUPER_SETUP_BDI */
 145 #if !defined(AFS_NONFSTRANS)
 146     sb->s_export_op = &afs_export_ops;
 147 #endif
 148 #if defined(MAX_NON_LFS)
 149 #ifdef AFS_64BIT_CLIENT
 150 #if !defined(MAX_LFS_FILESIZE)
 151 #if BITS_PER_LONG==32
 152 #define MAX_LFS_FILESIZE (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
 153 #elif BITS_PER_LONG==64
 154 #define MAX_LFS_FILESIZE 0x7fffffffffffffff
 155 #endif
 156 #endif
 157     sb->s_maxbytes = MAX_LFS_FILESIZE;
 158 #else
 159     sb->s_maxbytes = MAX_NON_LFS;
 160 #endif
 161 #endif
 162     code = afs_root(sb);
 163 out:
 164     if (code) {
 165         afs_globalVFS = NULL;
 166         afs_FlushAllVCaches();
 167 #if defined(HAVE_LINUX_BDI_INIT)
 168         if (bdi_init_done)
 169             bdi_destroy(afs_backing_dev_info);
 170 #endif
 171 #if !defined(HAVE_LINUX_SUPER_SETUP_BDI)
 172         kfree(afs_backing_dev_info);
 173 #endif
 174         module_put(THIS_MODULE);
 175     }
 176
 177     AFS_GUNLOCK();
 178     return code ? -EINVAL : 0;
 179 }
 180
 181
 182 /* afs_root - stat the root of the file system. AFS global held on entry. */
 183 static int
 184 afs_root(struct super_block *afsp)
 185 {
 186     afs_int32 code = 0;
 187     struct vcache *tvp = 0;
 188
 189     AFS_STATCNT(afs_root);
 190     if (afs_globalVp && (afs_globalVp->f.states & CStatd)) {
 191         tvp = afs_globalVp;
 192     } else {
 193         struct vrequest *treq = NULL;
 194         cred_t *credp = crref();
 195
 196         if (afs_globalVp) {
 197             afs_PutVCache(afs_globalVp);
 198             afs_globalVp = NULL;
 199         }
 200
 201         if (!(code = afs_CreateReq(&treq, credp)) && !(code = afs_CheckInit())) {
 202             tvp = afs_GetVCache(&afs_rootFid, treq, NULL, NULL);
 203             if (tvp) {
 204                 struct inode *ip = AFSTOV(tvp);
 205                 struct vattr *vattr = NULL;
 206
 207                 code = afs_CreateAttr(&vattr);
 208                 if (!code) {
 209                     afs_getattr(tvp, vattr, credp);
 210                     afs_fill_inode(ip, vattr);
 211
 212                     /* setup super_block and mount point inode. */
 213                     afs_globalVp = tvp;
 214 #if defined(HAVE_LINUX_D_MAKE_ROOT)
 215                     afsp->s_root = d_make_root(ip);
 216 #else
 217                     afsp->s_root = d_alloc_root(ip);
 218 #endif
 219 #if !defined(STRUCT_SUPER_BLOCK_HAS_S_D_OP)
 220                     afsp->s_root->d_op = &afs_dentry_operations;
 221 #endif
 222                     afs_DestroyAttr(vattr);
 223                 }
 224             } else
 225                 code = EIO;
 226         }
 227         crfree(credp);
 228         afs_DestroyReq(treq);
 229     }
 230
 231     afs_Trace2(afs_iclSetp, CM_TRACE_VFSROOT, ICL_TYPE_POINTER, afs_globalVp,
 232                ICL_TYPE_INT32, code);
 233     return code;
 234 }
 235
 236 /* super_operations */
 237
 238 #if defined(STRUCT_SUPER_OPERATIONS_HAS_ALLOC_INODE)
 239 static afs_kmem_cache_t *afs_inode_cachep;
 240
 241 static struct inode *
 242 afs_alloc_inode(struct super_block *sb)
 243 {
 244     struct vcache *vcp;
 245
 246     vcp = (struct vcache *) kmem_cache_alloc(afs_inode_cachep, KALLOC_TYPE);
 247     if (!vcp)
 248         return NULL;
 249
 250     return AFSTOV(vcp);
 251 }
 252
 253 static void
 254 afs_destroy_inode(struct inode *inode)
 255 {
 256     kmem_cache_free(afs_inode_cachep, inode);
 257 }
 258
 259 void
 260 init_once(void * foo)
 261 {
 262     struct vcache *vcp = (struct vcache *) foo;
 263
 264     inode_init_once(AFSTOV(vcp));
 265 }
 266
 267 int
 268 afs_init_inodecache(void)
 269 {
 270 #if defined(KMEM_CACHE_TAKES_DTOR)
 271     afs_inode_cachep = kmem_cache_create("afs_inode_cache",
 272                 sizeof(struct vcache), 0,
 273                 SLAB_HWCACHE_ALIGN | SLAB_RECLAIM_ACCOUNT, init_once_func, NULL);
 274 #else
 275     afs_inode_cachep = kmem_cache_create("afs_inode_cache",
 276                 sizeof(struct vcache), 0,
 277                 SLAB_HWCACHE_ALIGN | SLAB_RECLAIM_ACCOUNT, init_once_func);
 278 #endif
 279     if (afs_inode_cachep == NULL)
 280         return -ENOMEM;
 281     return 0;
 282 }
 283
 284 void
 285 afs_destroy_inodecache(void)
 286 {
 287     if (afs_inode_cachep)
 288         (void) kmem_cache_destroy(afs_inode_cachep);
 289 }
 290 #else
 291 int
 292 afs_init_inodecache(void)
 293 {
 294     return 0;
 295 }
 296
 297 void
 298 afs_destroy_inodecache(void)
 299 {
 300     return;
 301 }
 302 #endif
 303
 304 #if defined(STRUCT_SUPER_OPERATIONS_HAS_EVICT_INODE)
 305 static void
 306 afs_evict_inode(struct inode *ip)
 307 {
 308     struct vcache *vcp = VTOAFS(ip);
 309
 310     if (vcp->vlruq.prev || vcp->vlruq.next)
 311         osi_Panic("inode freed while on LRU");
 312     if (vcp->hnext)
 313         osi_Panic("inode freed while still hashed");
 314
 315     truncate_inode_pages(&ip->i_data, 0);
 316 #if defined(HAVE_LINUX_CLEAR_INODE)
 317     clear_inode(ip);
 318 #else
 319     end_writeback(ip);
 320 #endif
 321
 322 #if !defined(STRUCT_SUPER_OPERATIONS_HAS_ALLOC_INODE)
 323     afs_osi_Free(ip->u.generic_ip, sizeof(struct vcache));
 324 #endif
 325 }
 326 #else
 327 static void
 328 afs_clear_inode(struct inode *ip)
 329 {
 330     struct vcache *vcp = VTOAFS(ip);
 331
 332     if (vcp->vlruq.prev || vcp->vlruq.next)
 333         osi_Panic("inode freed while on LRU");
 334     if (vcp->hnext)
 335         osi_Panic("inode freed while still hashed");
 336
 337 #if !defined(STRUCT_SUPER_OPERATIONS_HAS_ALLOC_INODE)
 338     afs_osi_Free(ip->u.generic_ip, sizeof(struct vcache));
 339 #endif
 340 }
 341 #endif
 342
 343 /* afs_put_super
 344  * Called from unmount to release super_block. */
 345 static void
 346 afs_put_super(struct super_block *sbp)
 347 {
 348     AFS_GLOCK();
 349     AFS_STATCNT(afs_unmount);
 350
 351     afs_globalVFS = 0;
 352     afs_globalVp = 0;
 353
 354     afs_shutdown();
 355     mntput(afs_cacheMnt);
 356
 357     osi_linux_verify_alloced_memory();
 358 #if defined(HAVE_LINUX_BDI_INIT)
 359     bdi_destroy(afs_backing_dev_info);
 360 #endif
 361     kfree(afs_backing_dev_info);
 362     AFS_GUNLOCK();
 363
 364     sbp->s_dev = 0;
 365     module_put(THIS_MODULE);
 366 }
 367
 368
 369 /* afs_statfs
 370  * statp is in user space, so we need to cobble together a statfs, then
 371  * copy it.
 372  */
 373 int
 374 #if defined(STATFS_TAKES_DENTRY)
 375 afs_statfs(struct dentry *dentry, struct kstatfs *statp)
 376 #else
 377 afs_statfs(struct super_block *sbp, struct kstatfs *statp)
 378 #endif
 379 {
 380     memset(statp, 0, sizeof(*statp));
 381
 382     AFS_STATCNT(afs_statfs);
 383
 384     /* hardcode in case that which is giveth is taken away */
 385     statp->f_type = 0x5346414F;
 386 #if defined(STATFS_TAKES_DENTRY)
 387     statp->f_bsize = dentry->d_sb->s_blocksize;
 388 #else
 389     statp->f_bsize = sbp->s_blocksize;
 390 #endif
 391     statp->f_blocks = statp->f_bfree = statp->f_bavail = statp->f_files =
 392         statp->f_ffree = AFS_VFS_FAKEFREE;
 393     statp->f_fsid.val[0] = AFS_VFSMAGIC;
 394     statp->f_fsid.val[1] = AFS_VFSFSID;
 395     statp->f_namelen = 256;
 396
 397     return 0;
 398 }
 399
 400 struct super_operations afs_sops = {
 401 #if defined(STRUCT_SUPER_OPERATIONS_HAS_ALLOC_INODE)
 402   .alloc_inode =        afs_alloc_inode,
 403   .destroy_inode =      afs_destroy_inode,
 404 #endif
 405 #if defined(STRUCT_SUPER_OPERATIONS_HAS_EVICT_INODE)
 406   .evict_inode =        afs_evict_inode,
 407 #else
 408   .clear_inode =        afs_clear_inode,
 409 #endif
 410   .put_super =          afs_put_super,
 411   .statfs =             afs_statfs,
 412 };