1 /* 2 * Super block/filesystem wide operations 3 * 4 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and 5 * Michael Callahan <callahan@maths.ox.ac.uk> 6 * 7 * Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu> 8 * Copyright (C) Carnegie Mellon University 9 */ 10 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/mm.h> 14 #include <linux/string.h> 15 #include <linux/stat.h> 16 #include <linux/errno.h> 17 #include <linux/unistd.h> 18 #include <linux/mutex.h> 19 #include <linux/spinlock.h> 20 #include <linux/file.h> 21 #include <linux/vfs.h> 22 #include <linux/slab.h> 23 #include <linux/pid_namespace.h> 24 #include <linux/uaccess.h> 25 #include <linux/fs.h> 26 #include <linux/vmalloc.h> 27 28 #include <linux/coda.h> 29 #include <linux/coda_psdev.h> 30 #include "coda_linux.h" 31 #include "coda_cache.h" 32 33 #include "coda_int.h" 34 35 /* VFS super_block ops */ 36 static void coda_evict_inode(struct inode *); 37 static void coda_put_super(struct super_block *); 38 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf); 39 40 static struct kmem_cache * coda_inode_cachep; 41 42 static struct inode *coda_alloc_inode(struct super_block *sb) 43 { 44 struct coda_inode_info *ei; 45 ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL); 46 if (!ei) 47 return NULL; 48 memset(&ei->c_fid, 0, sizeof(struct CodaFid)); 49 ei->c_flags = 0; 50 ei->c_uid = GLOBAL_ROOT_UID; 51 ei->c_cached_perm = 0; 52 spin_lock_init(&ei->c_lock); 53 return &ei->vfs_inode; 54 } 55 56 static void coda_i_callback(struct rcu_head *head) 57 { 58 struct inode *inode = container_of(head, struct inode, i_rcu); 59 kmem_cache_free(coda_inode_cachep, ITOC(inode)); 60 } 61 62 static void coda_destroy_inode(struct inode *inode) 63 { 64 call_rcu(&inode->i_rcu, coda_i_callback); 65 } 66 67 static void init_once(void *foo) 68 { 69 struct coda_inode_info *ei = (struct coda_inode_info *) foo; 70 71 inode_init_once(&ei->vfs_inode); 72 } 73 74 int __init coda_init_inodecache(void) 75 { 76 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 77 sizeof(struct coda_inode_info), 0, 78 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| 79 SLAB_ACCOUNT, init_once); 80 if (coda_inode_cachep == NULL) 81 return -ENOMEM; 82 return 0; 83 } 84 85 void coda_destroy_inodecache(void) 86 { 87 /* 88 * Make sure all delayed rcu free inodes are flushed before we 89 * destroy cache. 90 */ 91 rcu_barrier(); 92 kmem_cache_destroy(coda_inode_cachep); 93 } 94 95 static int coda_remount(struct super_block *sb, int *flags, char *data) 96 { 97 sync_filesystem(sb); 98 *flags |= MS_NOATIME; 99 return 0; 100 } 101 102 /* exported operations */ 103 static const struct super_operations coda_super_operations = 104 { 105 .alloc_inode = coda_alloc_inode, 106 .destroy_inode = coda_destroy_inode, 107 .evict_inode = coda_evict_inode, 108 .put_super = coda_put_super, 109 .statfs = coda_statfs, 110 .remount_fs = coda_remount, 111 }; 112 113 static int get_device_index(struct coda_mount_data *data) 114 { 115 struct fd f; 116 struct inode *inode; 117 int idx; 118 119 if (data == NULL) { 120 pr_warn("%s: Bad mount data\n", __func__); 121 return -1; 122 } 123 124 if (data->version != CODA_MOUNT_VERSION) { 125 pr_warn("%s: Bad mount version\n", __func__); 126 return -1; 127 } 128 129 f = fdget(data->fd); 130 if (!f.file) 131 goto Ebadf; 132 inode = file_inode(f.file); 133 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) { 134 fdput(f); 135 goto Ebadf; 136 } 137 138 idx = iminor(inode); 139 fdput(f); 140 141 if (idx < 0 || idx >= MAX_CODADEVS) { 142 pr_warn("%s: Bad minor number\n", __func__); 143 return -1; 144 } 145 146 return idx; 147 Ebadf: 148 pr_warn("%s: Bad file\n", __func__); 149 return -1; 150 } 151 152 static int coda_fill_super(struct super_block *sb, void *data, int silent) 153 { 154 struct inode *root = NULL; 155 struct venus_comm *vc; 156 struct CodaFid fid; 157 int error; 158 int idx; 159 160 if (task_active_pid_ns(current) != &init_pid_ns) 161 return -EINVAL; 162 163 idx = get_device_index((struct coda_mount_data *) data); 164 165 /* Ignore errors in data, for backward compatibility */ 166 if(idx == -1) 167 idx = 0; 168 169 pr_info("%s: device index: %i\n", __func__, idx); 170 171 vc = &coda_comms[idx]; 172 mutex_lock(&vc->vc_mutex); 173 174 if (!vc->vc_inuse) { 175 pr_warn("%s: No pseudo device\n", __func__); 176 error = -EINVAL; 177 goto unlock_out; 178 } 179 180 if (vc->vc_sb) { 181 pr_warn("%s: Device already mounted\n", __func__); 182 error = -EBUSY; 183 goto unlock_out; 184 } 185 186 vc->vc_sb = sb; 187 mutex_unlock(&vc->vc_mutex); 188 189 sb->s_fs_info = vc; 190 sb->s_flags |= MS_NOATIME; 191 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ 192 sb->s_blocksize_bits = 12; 193 sb->s_magic = CODA_SUPER_MAGIC; 194 sb->s_op = &coda_super_operations; 195 sb->s_d_op = &coda_dentry_operations; 196 197 error = super_setup_bdi(sb); 198 if (error) 199 goto error; 200 201 /* get root fid from Venus: this needs the root inode */ 202 error = venus_rootfid(sb, &fid); 203 if ( error ) { 204 pr_warn("%s: coda_get_rootfid failed with %d\n", 205 __func__, error); 206 goto error; 207 } 208 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); 209 210 /* make root inode */ 211 root = coda_cnode_make(&fid, sb); 212 if (IS_ERR(root)) { 213 error = PTR_ERR(root); 214 pr_warn("Failure of coda_cnode_make for root: error %d\n", 215 error); 216 goto error; 217 } 218 219 pr_info("%s: rootinode is %ld dev %s\n", 220 __func__, root->i_ino, root->i_sb->s_id); 221 sb->s_root = d_make_root(root); 222 if (!sb->s_root) { 223 error = -EINVAL; 224 goto error; 225 } 226 return 0; 227 228 error: 229 mutex_lock(&vc->vc_mutex); 230 vc->vc_sb = NULL; 231 sb->s_fs_info = NULL; 232 unlock_out: 233 mutex_unlock(&vc->vc_mutex); 234 return error; 235 } 236 237 static void coda_put_super(struct super_block *sb) 238 { 239 struct venus_comm *vcp = coda_vcp(sb); 240 mutex_lock(&vcp->vc_mutex); 241 vcp->vc_sb = NULL; 242 sb->s_fs_info = NULL; 243 mutex_unlock(&vcp->vc_mutex); 244 245 pr_info("Bye bye.\n"); 246 } 247 248 static void coda_evict_inode(struct inode *inode) 249 { 250 truncate_inode_pages_final(&inode->i_data); 251 clear_inode(inode); 252 coda_cache_clear_inode(inode); 253 } 254 255 int coda_getattr(const struct path *path, struct kstat *stat, 256 u32 request_mask, unsigned int flags) 257 { 258 int err = coda_revalidate_inode(d_inode(path->dentry)); 259 if (!err) 260 generic_fillattr(d_inode(path->dentry), stat); 261 return err; 262 } 263 264 int coda_setattr(struct dentry *de, 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