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_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; 191 192 error = super_setup_bdi(sb); 193 if (error) 194 goto error; 195 196 /* get root fid from Venus: this needs the root inode */ 197 error = venus_rootfid(sb, &fid); 198 if ( error ) { 199 pr_warn("%s: coda_get_rootfid failed with %d\n", 200 __func__, error); 201 goto error; 202 } 203 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); 204 205 /* make root inode */ 206 root = coda_cnode_make(&fid, sb); 207 if (IS_ERR(root)) { 208 error = PTR_ERR(root); 209 pr_warn("Failure of coda_cnode_make for root: error %d\n", 210 error); 211 goto error; 212 } 213 214 pr_info("%s: rootinode is %ld dev %s\n", 215 __func__, root->i_ino, root->i_sb->s_id); 216 sb->s_root = d_make_root(root); 217 if (!sb->s_root) { 218 error = -EINVAL; 219 goto error; 220 } 221 return 0; 222 223 error: 224 mutex_lock(&vc->vc_mutex); 225 vc->vc_sb = NULL; 226 sb->s_fs_info = NULL; 227 unlock_out: 228 mutex_unlock(&vc->vc_mutex); 229 return error; 230 } 231 232 static void coda_put_super(struct super_block *sb) 233 { 234 struct venus_comm *vcp = coda_vcp(sb); 235 mutex_lock(&vcp->vc_mutex); 236 vcp->vc_sb = NULL; 237 sb->s_fs_info = NULL; 238 mutex_unlock(&vcp->vc_mutex); 239 240 pr_info("Bye bye.\n"); 241 } 242 243 static void coda_evict_inode(struct inode *inode) 244 { 245 truncate_inode_pages_final(&inode->i_data); 246 clear_inode(inode); 247 coda_cache_clear_inode(inode); 248 } 249 250 int coda_getattr(const struct path *path, struct kstat *stat, 251 u32 request_mask, unsigned int flags) 252 { 253 int err = coda_revalidate_inode(d_inode(path->dentry)); 254 if (!err) 255 generic_fillattr(d_inode(path->dentry), stat); 256 return err; 257 } 258 259 int coda_setattr(struct dentry *de, struct iattr *iattr) 260 { 261 struct inode *inode = d_inode(de); 262 struct coda_vattr vattr; 263 int error; 264 265 memset(&vattr, 0, sizeof(vattr)); 266 267 inode->i_ctime = current_time(inode); 268 coda_iattr_to_vattr(iattr, &vattr); 269 vattr.va_type = C_VNON; /* cannot set type */ 270 271 /* Venus is responsible for truncating the container-file!!! */ 272 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); 273 274 if (!error) { 275 coda_vattr_to_iattr(inode, &vattr); 276 coda_cache_clear_inode(inode); 277 } 278 return error; 279 } 280 281 const struct inode_operations coda_file_inode_operations = { 282 .permission = coda_permission, 283 .getattr = coda_getattr, 284 .setattr = coda_setattr, 285 }; 286 287 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) 288 { 289 int error; 290 291 error = venus_statfs(dentry, buf); 292 293 if (error) { 294 /* fake something like AFS does */ 295 buf->f_blocks = 9000000; 296 buf->f_bfree = 9000000; 297 buf->f_bavail = 9000000; 298 buf->f_files = 9000000; 299 buf->f_ffree = 9000000; 300 } 301 302 /* and fill in the rest */ 303 buf->f_type = CODA_SUPER_MAGIC; 304 buf->f_bsize = 4096; 305 buf->f_namelen = CODA_MAXNAMLEN; 306 307 return 0; 308 } 309 310 /* init_coda: used by filesystems.c to register coda */ 311 312 static struct dentry *coda_mount(struct file_system_type *fs_type, 313 int flags, const char *dev_name, void *data) 314 { 315 return mount_nodev(fs_type, flags, data, coda_fill_super); 316 } 317 318 struct file_system_type coda_fs_type = { 319 .owner = THIS_MODULE, 320 .name = "coda", 321 .mount = coda_mount, 322 .kill_sb = kill_anon_super, 323 .fs_flags = FS_BINARY_MOUNTDATA, 324 }; 325 MODULE_ALIAS_FS("coda"); 326 327