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/fs_context.h> 28 #include <linux/fs_parser.h> 29 #include <linux/vmalloc.h> 30 31 #include <linux/coda.h> 32 #include "coda_psdev.h" 33 #include "coda_linux.h" 34 #include "coda_cache.h" 35 36 #include "coda_int.h" 37 38 /* VFS super_block ops */ 39 static void coda_evict_inode(struct inode *); 40 static void coda_put_super(struct super_block *); 41 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf); 42 43 static struct kmem_cache * coda_inode_cachep; 44 45 static struct inode *coda_alloc_inode(struct super_block *sb) 46 { 47 struct coda_inode_info *ei; 48 ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL); 49 if (!ei) 50 return NULL; 51 memset(&ei->c_fid, 0, sizeof(struct CodaFid)); 52 ei->c_flags = 0; 53 ei->c_uid = GLOBAL_ROOT_UID; 54 ei->c_cached_perm = 0; 55 spin_lock_init(&ei->c_lock); 56 return &ei->vfs_inode; 57 } 58 59 static void coda_free_inode(struct inode *inode) 60 { 61 kmem_cache_free(coda_inode_cachep, ITOC(inode)); 62 } 63 64 static void init_once(void *foo) 65 { 66 struct coda_inode_info *ei = (struct coda_inode_info *) foo; 67 68 inode_init_once(&ei->vfs_inode); 69 } 70 71 int __init coda_init_inodecache(void) 72 { 73 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 74 sizeof(struct coda_inode_info), 0, 75 SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT, 76 init_once); 77 if (coda_inode_cachep == NULL) 78 return -ENOMEM; 79 return 0; 80 } 81 82 void coda_destroy_inodecache(void) 83 { 84 /* 85 * Make sure all delayed rcu free inodes are flushed before we 86 * destroy cache. 87 */ 88 rcu_barrier(); 89 kmem_cache_destroy(coda_inode_cachep); 90 } 91 92 static int coda_reconfigure(struct fs_context *fc) 93 { 94 sync_filesystem(fc->root->d_sb); 95 fc->sb_flags |= SB_NOATIME; 96 return 0; 97 } 98 99 /* exported operations */ 100 static const struct super_operations coda_super_operations = 101 { 102 .alloc_inode = coda_alloc_inode, 103 .free_inode = coda_free_inode, 104 .evict_inode = coda_evict_inode, 105 .put_super = coda_put_super, 106 .statfs = coda_statfs, 107 }; 108 109 struct coda_fs_context { 110 int idx; 111 }; 112 113 enum { 114 Opt_fd, 115 }; 116 117 static const struct fs_parameter_spec coda_param_specs[] = { 118 fsparam_fd ("fd", Opt_fd), 119 {} 120 }; 121 122 static int coda_parse_fd(struct fs_context *fc, int fd) 123 { 124 struct coda_fs_context *ctx = fc->fs_private; 125 struct fd f; 126 struct inode *inode; 127 int idx; 128 129 f = fdget(fd); 130 if (!f.file) 131 return -EBADF; 132 inode = file_inode(f.file); 133 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) { 134 fdput(f); 135 return invalf(fc, "code: Not coda psdev"); 136 } 137 138 idx = iminor(inode); 139 fdput(f); 140 141 if (idx < 0 || idx >= MAX_CODADEVS) 142 return invalf(fc, "coda: Bad minor number"); 143 ctx->idx = idx; 144 return 0; 145 } 146 147 static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param) 148 { 149 struct fs_parse_result result; 150 int opt; 151 152 opt = fs_parse(fc, coda_param_specs, param, &result); 153 if (opt < 0) 154 return opt; 155 156 switch (opt) { 157 case Opt_fd: 158 return coda_parse_fd(fc, result.uint_32); 159 } 160 161 return 0; 162 } 163 164 /* 165 * Parse coda's binary mount data form. We ignore any errors and go with index 166 * 0 if we get one for backward compatibility. 167 */ 168 static int coda_parse_monolithic(struct fs_context *fc, void *_data) 169 { 170 struct coda_mount_data *data = _data; 171 172 if (!data) 173 return invalf(fc, "coda: Bad mount data"); 174 175 if (data->version != CODA_MOUNT_VERSION) 176 return invalf(fc, "coda: Bad mount version"); 177 178 coda_parse_fd(fc, data->fd); 179 return 0; 180 } 181 182 static int coda_fill_super(struct super_block *sb, struct fs_context *fc) 183 { 184 struct coda_fs_context *ctx = fc->fs_private; 185 struct inode *root = NULL; 186 struct venus_comm *vc; 187 struct CodaFid fid; 188 int error; 189 190 infof(fc, "coda: device index: %i\n", ctx->idx); 191 192 vc = &coda_comms[ctx->idx]; 193 mutex_lock(&vc->vc_mutex); 194 195 if (!vc->vc_inuse) { 196 errorf(fc, "coda: No pseudo device"); 197 error = -EINVAL; 198 goto unlock_out; 199 } 200 201 if (vc->vc_sb) { 202 errorf(fc, "coda: Device already mounted"); 203 error = -EBUSY; 204 goto unlock_out; 205 } 206 207 vc->vc_sb = sb; 208 mutex_unlock(&vc->vc_mutex); 209 210 sb->s_fs_info = vc; 211 sb->s_flags |= SB_NOATIME; 212 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ 213 sb->s_blocksize_bits = 12; 214 sb->s_magic = CODA_SUPER_MAGIC; 215 sb->s_op = &coda_super_operations; 216 sb->s_d_op = &coda_dentry_operations; 217 sb->s_time_gran = 1; 218 sb->s_time_min = S64_MIN; 219 sb->s_time_max = S64_MAX; 220 221 error = super_setup_bdi(sb); 222 if (error) 223 goto error; 224 225 /* get root fid from Venus: this needs the root inode */ 226 error = venus_rootfid(sb, &fid); 227 if ( error ) { 228 pr_warn("%s: coda_get_rootfid failed with %d\n", 229 __func__, error); 230 goto error; 231 } 232 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); 233 234 /* make root inode */ 235 root = coda_cnode_make(&fid, sb); 236 if (IS_ERR(root)) { 237 error = PTR_ERR(root); 238 pr_warn("Failure of coda_cnode_make for root: error %d\n", 239 error); 240 goto error; 241 } 242 243 pr_info("%s: rootinode is %ld dev %s\n", 244 __func__, root->i_ino, root->i_sb->s_id); 245 sb->s_root = d_make_root(root); 246 if (!sb->s_root) { 247 error = -EINVAL; 248 goto error; 249 } 250 return 0; 251 252 error: 253 mutex_lock(&vc->vc_mutex); 254 vc->vc_sb = NULL; 255 sb->s_fs_info = NULL; 256 unlock_out: 257 mutex_unlock(&vc->vc_mutex); 258 return error; 259 } 260 261 static void coda_put_super(struct super_block *sb) 262 { 263 struct venus_comm *vcp = coda_vcp(sb); 264 mutex_lock(&vcp->vc_mutex); 265 vcp->vc_sb = NULL; 266 sb->s_fs_info = NULL; 267 mutex_unlock(&vcp->vc_mutex); 268 mutex_destroy(&vcp->vc_mutex); 269 270 pr_info("Bye bye.\n"); 271 } 272 273 static void coda_evict_inode(struct inode *inode) 274 { 275 truncate_inode_pages_final(&inode->i_data); 276 clear_inode(inode); 277 coda_cache_clear_inode(inode); 278 } 279 280 int coda_getattr(struct mnt_idmap *idmap, const struct path *path, 281 struct kstat *stat, u32 request_mask, unsigned int flags) 282 { 283 int err = coda_revalidate_inode(d_inode(path->dentry)); 284 if (!err) 285 generic_fillattr(&nop_mnt_idmap, request_mask, 286 d_inode(path->dentry), stat); 287 return err; 288 } 289 290 int coda_setattr(struct mnt_idmap *idmap, struct dentry *de, 291 struct iattr *iattr) 292 { 293 struct inode *inode = d_inode(de); 294 struct coda_vattr vattr; 295 int error; 296 297 memset(&vattr, 0, sizeof(vattr)); 298 299 inode_set_ctime_current(inode); 300 coda_iattr_to_vattr(iattr, &vattr); 301 vattr.va_type = C_VNON; /* cannot set type */ 302 303 /* Venus is responsible for truncating the container-file!!! */ 304 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); 305 306 if (!error) { 307 coda_vattr_to_iattr(inode, &vattr); 308 coda_cache_clear_inode(inode); 309 } 310 return error; 311 } 312 313 const struct inode_operations coda_file_inode_operations = { 314 .permission = coda_permission, 315 .getattr = coda_getattr, 316 .setattr = coda_setattr, 317 }; 318 319 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) 320 { 321 int error; 322 323 error = venus_statfs(dentry, buf); 324 325 if (error) { 326 /* fake something like AFS does */ 327 buf->f_blocks = 9000000; 328 buf->f_bfree = 9000000; 329 buf->f_bavail = 9000000; 330 buf->f_files = 9000000; 331 buf->f_ffree = 9000000; 332 } 333 334 /* and fill in the rest */ 335 buf->f_type = CODA_SUPER_MAGIC; 336 buf->f_bsize = 4096; 337 buf->f_namelen = CODA_MAXNAMLEN; 338 339 return 0; 340 } 341 342 static int coda_get_tree(struct fs_context *fc) 343 { 344 if (task_active_pid_ns(current) != &init_pid_ns) 345 return -EINVAL; 346 347 return get_tree_nodev(fc, coda_fill_super); 348 } 349 350 static void coda_free_fc(struct fs_context *fc) 351 { 352 kfree(fc->fs_private); 353 } 354 355 static const struct fs_context_operations coda_context_ops = { 356 .free = coda_free_fc, 357 .parse_param = coda_parse_param, 358 .parse_monolithic = coda_parse_monolithic, 359 .get_tree = coda_get_tree, 360 .reconfigure = coda_reconfigure, 361 }; 362 363 static int coda_init_fs_context(struct fs_context *fc) 364 { 365 struct coda_fs_context *ctx; 366 367 ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL); 368 if (!ctx) 369 return -ENOMEM; 370 371 fc->fs_private = ctx; 372 fc->ops = &coda_context_ops; 373 return 0; 374 } 375 376 struct file_system_type coda_fs_type = { 377 .owner = THIS_MODULE, 378 .name = "coda", 379 .init_fs_context = coda_init_fs_context, 380 .parameters = coda_param_specs, 381 .kill_sb = kill_anon_super, 382 .fs_flags = FS_BINARY_MOUNTDATA, 383 }; 384 MODULE_ALIAS_FS("coda"); 385 386