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"); 332 333