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 "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_free_inode(struct inode *inode) 58 { 59 kmem_cache_free(coda_inode_cachep, ITOC(inode)); 60 } 61 62 static void init_once(void *foo) 63 { 64 struct coda_inode_info *ei = (struct coda_inode_info *) foo; 65 66 inode_init_once(&ei->vfs_inode); 67 } 68 69 int __init coda_init_inodecache(void) 70 { 71 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 72 sizeof(struct coda_inode_info), 0, 73 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| 74 SLAB_ACCOUNT, init_once); 75 if (coda_inode_cachep == NULL) 76 return -ENOMEM; 77 return 0; 78 } 79 80 void coda_destroy_inodecache(void) 81 { 82 /* 83 * Make sure all delayed rcu free inodes are flushed before we 84 * destroy cache. 85 */ 86 rcu_barrier(); 87 kmem_cache_destroy(coda_inode_cachep); 88 } 89 90 static int coda_remount(struct super_block *sb, int *flags, char *data) 91 { 92 sync_filesystem(sb); 93 *flags |= SB_NOATIME; 94 return 0; 95 } 96 97 /* exported operations */ 98 static const struct super_operations coda_super_operations = 99 { 100 .alloc_inode = coda_alloc_inode, 101 .free_inode = coda_free_inode, 102 .evict_inode = coda_evict_inode, 103 .put_super = coda_put_super, 104 .statfs = coda_statfs, 105 .remount_fs = coda_remount, 106 }; 107 108 static int get_device_index(struct coda_mount_data *data) 109 { 110 struct fd f; 111 struct inode *inode; 112 int idx; 113 114 if (data == NULL) { 115 pr_warn("%s: Bad mount data\n", __func__); 116 return -1; 117 } 118 119 if (data->version != CODA_MOUNT_VERSION) { 120 pr_warn("%s: Bad mount version\n", __func__); 121 return -1; 122 } 123 124 f = fdget(data->fd); 125 if (!f.file) 126 goto Ebadf; 127 inode = file_inode(f.file); 128 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) { 129 fdput(f); 130 goto Ebadf; 131 } 132 133 idx = iminor(inode); 134 fdput(f); 135 136 if (idx < 0 || idx >= MAX_CODADEVS) { 137 pr_warn("%s: Bad minor number\n", __func__); 138 return -1; 139 } 140 141 return idx; 142 Ebadf: 143 pr_warn("%s: Bad file\n", __func__); 144 return -1; 145 } 146 147 static int coda_fill_super(struct super_block *sb, void *data, int silent) 148 { 149 struct inode *root = NULL; 150 struct venus_comm *vc; 151 struct CodaFid fid; 152 int error; 153 int idx; 154 155 if (task_active_pid_ns(current) != &init_pid_ns) 156 return -EINVAL; 157 158 idx = get_device_index((struct coda_mount_data *) data); 159 160 /* Ignore errors in data, for backward compatibility */ 161 if(idx == -1) 162 idx = 0; 163 164 pr_info("%s: device index: %i\n", __func__, idx); 165 166 vc = &coda_comms[idx]; 167 mutex_lock(&vc->vc_mutex); 168 169 if (!vc->vc_inuse) { 170 pr_warn("%s: No pseudo device\n", __func__); 171 error = -EINVAL; 172 goto unlock_out; 173 } 174 175 if (vc->vc_sb) { 176 pr_warn("%s: Device already mounted\n", __func__); 177 error = -EBUSY; 178 goto unlock_out; 179 } 180 181 vc->vc_sb = sb; 182 mutex_unlock(&vc->vc_mutex); 183 184 sb->s_fs_info = vc; 185 sb->s_flags |= SB_NOATIME; 186 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ 187 sb->s_blocksize_bits = 12; 188 sb->s_magic = CODA_SUPER_MAGIC; 189 sb->s_op = &coda_super_operations; 190 sb->s_d_op = &coda_dentry_operations; 191 sb->s_time_gran = 1; 192 sb->s_time_min = S64_MIN; 193 sb->s_time_max = S64_MAX; 194 195 error = super_setup_bdi(sb); 196 if (error) 197 goto error; 198 199 /* get root fid from Venus: this needs the root inode */ 200 error = venus_rootfid(sb, &fid); 201 if ( error ) { 202 pr_warn("%s: coda_get_rootfid failed with %d\n", 203 __func__, error); 204 goto error; 205 } 206 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); 207 208 /* make root inode */ 209 root = coda_cnode_make(&fid, sb); 210 if (IS_ERR(root)) { 211 error = PTR_ERR(root); 212 pr_warn("Failure of coda_cnode_make for root: error %d\n", 213 error); 214 goto error; 215 } 216 217 pr_info("%s: rootinode is %ld dev %s\n", 218 __func__, root->i_ino, root->i_sb->s_id); 219 sb->s_root = d_make_root(root); 220 if (!sb->s_root) { 221 error = -EINVAL; 222 goto error; 223 } 224 return 0; 225 226 error: 227 mutex_lock(&vc->vc_mutex); 228 vc->vc_sb = NULL; 229 sb->s_fs_info = NULL; 230 unlock_out: 231 mutex_unlock(&vc->vc_mutex); 232 return error; 233 } 234 235 static void coda_put_super(struct super_block *sb) 236 { 237 struct venus_comm *vcp = coda_vcp(sb); 238 mutex_lock(&vcp->vc_mutex); 239 vcp->vc_sb = NULL; 240 sb->s_fs_info = NULL; 241 mutex_unlock(&vcp->vc_mutex); 242 mutex_destroy(&vcp->vc_mutex); 243 244 pr_info("Bye bye.\n"); 245 } 246 247 static void coda_evict_inode(struct inode *inode) 248 { 249 truncate_inode_pages_final(&inode->i_data); 250 clear_inode(inode); 251 coda_cache_clear_inode(inode); 252 } 253 254 int coda_getattr(struct user_namespace *mnt_userns, const struct path *path, 255 struct kstat *stat, u32 request_mask, unsigned int flags) 256 { 257 int err = coda_revalidate_inode(d_inode(path->dentry)); 258 if (!err) 259 generic_fillattr(&init_user_ns, d_inode(path->dentry), stat); 260 return err; 261 } 262 263 int coda_setattr(struct user_namespace *mnt_userns, struct dentry *de, 264 struct iattr *iattr) 265 { 266 struct inode *inode = d_inode(de); 267 struct coda_vattr vattr; 268 int error; 269 270 memset(&vattr, 0, sizeof(vattr)); 271 272 inode->i_ctime = current_time(inode); 273 coda_iattr_to_vattr(iattr, &vattr); 274 vattr.va_type = C_VNON; /* cannot set type */ 275 276 /* Venus is responsible for truncating the container-file!!! */ 277 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); 278 279 if (!error) { 280 coda_vattr_to_iattr(inode, &vattr); 281 coda_cache_clear_inode(inode); 282 } 283 return error; 284 } 285 286 const struct inode_operations coda_file_inode_operations = { 287 .permission = coda_permission, 288 .getattr = coda_getattr, 289 .setattr = coda_setattr, 290 }; 291 292 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) 293 { 294 int error; 295 296 error = venus_statfs(dentry, buf); 297 298 if (error) { 299 /* fake something like AFS does */ 300 buf->f_blocks = 9000000; 301 buf->f_bfree = 9000000; 302 buf->f_bavail = 9000000; 303 buf->f_files = 9000000; 304 buf->f_ffree = 9000000; 305 } 306 307 /* and fill in the rest */ 308 buf->f_type = CODA_SUPER_MAGIC; 309 buf->f_bsize = 4096; 310 buf->f_namelen = CODA_MAXNAMLEN; 311 312 return 0; 313 } 314 315 /* init_coda: used by filesystems.c to register coda */ 316 317 static struct dentry *coda_mount(struct file_system_type *fs_type, 318 int flags, const char *dev_name, void *data) 319 { 320 return mount_nodev(fs_type, flags, data, coda_fill_super); 321 } 322 323 struct file_system_type coda_fs_type = { 324 .owner = THIS_MODULE, 325 .name = "coda", 326 .mount = coda_mount, 327 .kill_sb = kill_anon_super, 328 .fs_flags = FS_BINARY_MOUNTDATA, 329 }; 330 MODULE_ALIAS_FS("coda"); 331 332