| 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 | |