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1// SPDX-License-Identifier: GPL-2.02/*3 * Super block/filesystem wide operations4 *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 University10 */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 */39static void coda_evict_inode(struct inode *);40static void coda_put_super(struct super_block *);41static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);42 43static struct kmem_cache * coda_inode_cachep;44 45static 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 59static void coda_free_inode(struct inode *inode)60{61 kmem_cache_free(coda_inode_cachep, ITOC(inode));62}63 64static 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 71int __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 82void coda_destroy_inodecache(void)83{84 /*85 * Make sure all delayed rcu free inodes are flushed before we86 * destroy cache.87 */88 rcu_barrier();89 kmem_cache_destroy(coda_inode_cachep);90}91 92static 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 */100static 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 109struct coda_fs_context {110 int idx;111};112 113enum {114 Opt_fd,115};116 117static const struct fs_parameter_spec coda_param_specs[] = {118 fsparam_fd ("fd", Opt_fd),119 {}120};121 122static int coda_set_idx(struct fs_context *fc, struct file *file)123{124 struct coda_fs_context *ctx = fc->fs_private;125 struct inode *inode;126 int idx;127 128 inode = file_inode(file);129 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {130 return invalf(fc, "coda: Not coda psdev");131 }132 idx = iminor(inode);133 if (idx < 0 || idx >= MAX_CODADEVS)134 return invalf(fc, "coda: Bad minor number");135 ctx->idx = idx;136 return 0;137}138 139static int coda_parse_fd(struct fs_context *fc, struct fs_parameter *param,140 struct fs_parse_result *result)141{142 struct file *file;143 int err;144 145 if (param->type == fs_value_is_file) {146 file = param->file;147 param->file = NULL;148 } else {149 file = fget(result->uint_32);150 }151 if (!file)152 return -EBADF;153 154 err = coda_set_idx(fc, file);155 fput(file);156 return err;157}158 159static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)160{161 struct fs_parse_result result;162 int opt;163 164 opt = fs_parse(fc, coda_param_specs, param, &result);165 if (opt < 0)166 return opt;167 168 switch (opt) {169 case Opt_fd:170 return coda_parse_fd(fc, param, &result);171 }172 173 return 0;174}175 176/*177 * Parse coda's binary mount data form. We ignore any errors and go with index178 * 0 if we get one for backward compatibility.179 */180static int coda_parse_monolithic(struct fs_context *fc, void *_data)181{182 struct file *file;183 struct coda_mount_data *data = _data;184 185 if (!data)186 return invalf(fc, "coda: Bad mount data");187 188 if (data->version != CODA_MOUNT_VERSION)189 return invalf(fc, "coda: Bad mount version");190 191 file = fget(data->fd);192 if (file) {193 coda_set_idx(fc, file);194 fput(file);195 }196 return 0;197}198 199static int coda_fill_super(struct super_block *sb, struct fs_context *fc)200{201 struct coda_fs_context *ctx = fc->fs_private;202 struct inode *root = NULL;203 struct venus_comm *vc;204 struct CodaFid fid;205 int error;206 207 infof(fc, "coda: device index: %i\n", ctx->idx);208 209 vc = &coda_comms[ctx->idx];210 mutex_lock(&vc->vc_mutex);211 212 if (!vc->vc_inuse) {213 errorf(fc, "coda: No pseudo device");214 error = -EINVAL;215 goto unlock_out;216 }217 218 if (vc->vc_sb) {219 errorf(fc, "coda: Device already mounted");220 error = -EBUSY;221 goto unlock_out;222 }223 224 vc->vc_sb = sb;225 mutex_unlock(&vc->vc_mutex);226 227 sb->s_fs_info = vc;228 sb->s_flags |= SB_NOATIME;229 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */230 sb->s_blocksize_bits = 12;231 sb->s_magic = CODA_SUPER_MAGIC;232 sb->s_op = &coda_super_operations;233 sb->s_d_op = &coda_dentry_operations;234 sb->s_time_gran = 1;235 sb->s_time_min = S64_MIN;236 sb->s_time_max = S64_MAX;237 238 error = super_setup_bdi(sb);239 if (error)240 goto error;241 242 /* get root fid from Venus: this needs the root inode */243 error = venus_rootfid(sb, &fid);244 if ( error ) {245 pr_warn("%s: coda_get_rootfid failed with %d\n",246 __func__, error);247 goto error;248 }249 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));250 251 /* make root inode */252 root = coda_cnode_make(&fid, sb);253 if (IS_ERR(root)) {254 error = PTR_ERR(root);255 pr_warn("Failure of coda_cnode_make for root: error %d\n",256 error);257 goto error;258 } 259 260 pr_info("%s: rootinode is %ld dev %s\n",261 __func__, root->i_ino, root->i_sb->s_id);262 sb->s_root = d_make_root(root);263 if (!sb->s_root) {264 error = -EINVAL;265 goto error;266 }267 return 0;268 269error:270 mutex_lock(&vc->vc_mutex);271 vc->vc_sb = NULL;272 sb->s_fs_info = NULL;273unlock_out:274 mutex_unlock(&vc->vc_mutex);275 return error;276}277 278static void coda_put_super(struct super_block *sb)279{280 struct venus_comm *vcp = coda_vcp(sb);281 mutex_lock(&vcp->vc_mutex);282 vcp->vc_sb = NULL;283 sb->s_fs_info = NULL;284 mutex_unlock(&vcp->vc_mutex);285 mutex_destroy(&vcp->vc_mutex);286 287 pr_info("Bye bye.\n");288}289 290static void coda_evict_inode(struct inode *inode)291{292 truncate_inode_pages_final(&inode->i_data);293 clear_inode(inode);294 coda_cache_clear_inode(inode);295}296 297int coda_getattr(struct mnt_idmap *idmap, const struct path *path,298 struct kstat *stat, u32 request_mask, unsigned int flags)299{300 int err = coda_revalidate_inode(d_inode(path->dentry));301 if (!err)302 generic_fillattr(&nop_mnt_idmap, request_mask,303 d_inode(path->dentry), stat);304 return err;305}306 307int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,308 struct iattr *iattr)309{310 struct inode *inode = d_inode(de);311 struct coda_vattr vattr;312 int error;313 314 memset(&vattr, 0, sizeof(vattr)); 315 316 inode_set_ctime_current(inode);317 coda_iattr_to_vattr(iattr, &vattr);318 vattr.va_type = C_VNON; /* cannot set type */319 320 /* Venus is responsible for truncating the container-file!!! */321 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);322 323 if (!error) {324 coda_vattr_to_iattr(inode, &vattr); 325 coda_cache_clear_inode(inode);326 }327 return error;328}329 330const struct inode_operations coda_file_inode_operations = {331 .permission = coda_permission,332 .getattr = coda_getattr,333 .setattr = coda_setattr,334};335 336static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)337{338 int error;339 340 error = venus_statfs(dentry, buf);341 342 if (error) {343 /* fake something like AFS does */344 buf->f_blocks = 9000000;345 buf->f_bfree = 9000000;346 buf->f_bavail = 9000000;347 buf->f_files = 9000000;348 buf->f_ffree = 9000000;349 }350 351 /* and fill in the rest */352 buf->f_type = CODA_SUPER_MAGIC;353 buf->f_bsize = 4096;354 buf->f_namelen = CODA_MAXNAMLEN;355 356 return 0; 357}358 359static int coda_get_tree(struct fs_context *fc)360{361 if (task_active_pid_ns(current) != &init_pid_ns)362 return -EINVAL;363 364 return get_tree_nodev(fc, coda_fill_super);365}366 367static void coda_free_fc(struct fs_context *fc)368{369 kfree(fc->fs_private);370}371 372static const struct fs_context_operations coda_context_ops = {373 .free = coda_free_fc,374 .parse_param = coda_parse_param,375 .parse_monolithic = coda_parse_monolithic,376 .get_tree = coda_get_tree,377 .reconfigure = coda_reconfigure,378};379 380static int coda_init_fs_context(struct fs_context *fc)381{382 struct coda_fs_context *ctx;383 384 ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);385 if (!ctx)386 return -ENOMEM;387 388 fc->fs_private = ctx;389 fc->ops = &coda_context_ops;390 return 0;391}392 393struct file_system_type coda_fs_type = {394 .owner = THIS_MODULE,395 .name = "coda",396 .init_fs_context = coda_init_fs_context,397 .parameters = coda_param_specs,398 .kill_sb = kill_anon_super,399 .fs_flags = FS_BINARY_MOUNTDATA,400};401MODULE_ALIAS_FS("coda");402 403