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 25 #include <asm/uaccess.h> 26 27 #include <linux/fs.h> 28 #include <linux/vmalloc.h> 29 30 #include <linux/coda.h> 31 #include <linux/coda_psdev.h> 32 #include "coda_linux.h" 33 #include "coda_cache.h" 34 35 #include "coda_int.h" 36 37 /* VFS super_block ops */ 38 static void coda_evict_inode(struct inode *); 39 static void coda_put_super(struct super_block *); 40 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf); 41 42 static struct kmem_cache * coda_inode_cachep; 43 44 static struct inode *coda_alloc_inode(struct super_block *sb) 45 { 46 struct coda_inode_info *ei; 47 ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL); 48 if (!ei) 49 return NULL; 50 memset(&ei->c_fid, 0, sizeof(struct CodaFid)); 51 ei->c_flags = 0; 52 ei->c_uid = GLOBAL_ROOT_UID; 53 ei->c_cached_perm = 0; 54 spin_lock_init(&ei->c_lock); 55 return &ei->vfs_inode; 56 } 57 58 static void coda_i_callback(struct rcu_head *head) 59 { 60 struct inode *inode = container_of(head, struct inode, i_rcu); 61 kmem_cache_free(coda_inode_cachep, ITOC(inode)); 62 } 63 64 static void coda_destroy_inode(struct inode *inode) 65 { 66 call_rcu(&inode->i_rcu, coda_i_callback); 67 } 68 69 static void init_once(void *foo) 70 { 71 struct coda_inode_info *ei = (struct coda_inode_info *) foo; 72 73 inode_init_once(&ei->vfs_inode); 74 } 75 76 int coda_init_inodecache(void) 77 { 78 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 79 sizeof(struct coda_inode_info), 80 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 81 init_once); 82 if (coda_inode_cachep == NULL) 83 return -ENOMEM; 84 return 0; 85 } 86 87 void coda_destroy_inodecache(void) 88 { 89 /* 90 * Make sure all delayed rcu free inodes are flushed before we 91 * destroy cache. 92 */ 93 rcu_barrier(); 94 kmem_cache_destroy(coda_inode_cachep); 95 } 96 97 static int coda_remount(struct super_block *sb, int *flags, char *data) 98 { 99 *flags |= MS_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 printk("coda_read_super: Bad mount data\n"); 122 return -1; 123 } 124 125 if (data->version != CODA_MOUNT_VERSION) { 126 printk("coda_read_super: Bad mount version\n"); 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 printk("coda_read_super: Bad minor number\n"); 144 return -1; 145 } 146 147 return idx; 148 Ebadf: 149 printk("coda_read_super: Bad file\n"); 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 printk(KERN_INFO "coda_read_super: device index: %i\n", idx); 171 172 vc = &coda_comms[idx]; 173 mutex_lock(&vc->vc_mutex); 174 175 if (!vc->vc_inuse) { 176 printk("coda_read_super: No pseudo device\n"); 177 error = -EINVAL; 178 goto unlock_out; 179 } 180 181 if (vc->vc_sb) { 182 printk("coda_read_super: Device already mounted\n"); 183 error = -EBUSY; 184 goto unlock_out; 185 } 186 187 error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY); 188 if (error) 189 goto unlock_out; 190 191 vc->vc_sb = sb; 192 mutex_unlock(&vc->vc_mutex); 193 194 sb->s_fs_info = vc; 195 sb->s_flags |= MS_NOATIME; 196 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ 197 sb->s_blocksize_bits = 12; 198 sb->s_magic = CODA_SUPER_MAGIC; 199 sb->s_op = &coda_super_operations; 200 sb->s_d_op = &coda_dentry_operations; 201 sb->s_bdi = &vc->bdi; 202 203 /* get root fid from Venus: this needs the root inode */ 204 error = venus_rootfid(sb, &fid); 205 if ( error ) { 206 printk("coda_read_super: coda_get_rootfid failed with %d\n", 207 error); 208 goto error; 209 } 210 printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid)); 211 212 /* make root inode */ 213 root = coda_cnode_make(&fid, sb); 214 if (IS_ERR(root)) { 215 error = PTR_ERR(root); 216 printk("Failure of coda_cnode_make for root: error %d\n", error); 217 goto error; 218 } 219 220 printk("coda_read_super: rootinode is %ld dev %s\n", 221 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 bdi_destroy(&vc->bdi); 232 vc->vc_sb = NULL; 233 sb->s_fs_info = NULL; 234 unlock_out: 235 mutex_unlock(&vc->vc_mutex); 236 return error; 237 } 238 239 static void coda_put_super(struct super_block *sb) 240 { 241 struct venus_comm *vcp = coda_vcp(sb); 242 mutex_lock(&vcp->vc_mutex); 243 bdi_destroy(&vcp->bdi); 244 vcp->vc_sb = NULL; 245 sb->s_fs_info = NULL; 246 mutex_unlock(&vcp->vc_mutex); 247 248 printk("Coda: Bye bye.\n"); 249 } 250 251 static void coda_evict_inode(struct inode *inode) 252 { 253 truncate_inode_pages(&inode->i_data, 0); 254 clear_inode(inode); 255 coda_cache_clear_inode(inode); 256 } 257 258 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 259 { 260 int err = coda_revalidate_inode(dentry->d_inode); 261 if (!err) 262 generic_fillattr(dentry->d_inode, stat); 263 return err; 264 } 265 266 int coda_setattr(struct dentry *de, struct iattr *iattr) 267 { 268 struct inode *inode = de->d_inode; 269 struct coda_vattr vattr; 270 int error; 271 272 memset(&vattr, 0, sizeof(vattr)); 273 274 inode->i_ctime = CURRENT_TIME_SEC; 275 coda_iattr_to_vattr(iattr, &vattr); 276 vattr.va_type = C_VNON; /* cannot set type */ 277 278 /* Venus is responsible for truncating the container-file!!! */ 279 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); 280 281 if (!error) { 282 coda_vattr_to_iattr(inode, &vattr); 283 coda_cache_clear_inode(inode); 284 } 285 return error; 286 } 287 288 const struct inode_operations coda_file_inode_operations = { 289 .permission = coda_permission, 290 .getattr = coda_getattr, 291 .setattr = coda_setattr, 292 }; 293 294 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) 295 { 296 int error; 297 298 error = venus_statfs(dentry, buf); 299 300 if (error) { 301 /* fake something like AFS does */ 302 buf->f_blocks = 9000000; 303 buf->f_bfree = 9000000; 304 buf->f_bavail = 9000000; 305 buf->f_files = 9000000; 306 buf->f_ffree = 9000000; 307 } 308 309 /* and fill in the rest */ 310 buf->f_type = CODA_SUPER_MAGIC; 311 buf->f_bsize = 4096; 312 buf->f_namelen = CODA_MAXNAMLEN; 313 314 return 0; 315 } 316 317 /* init_coda: used by filesystems.c to register coda */ 318 319 static struct dentry *coda_mount(struct file_system_type *fs_type, 320 int flags, const char *dev_name, void *data) 321 { 322 return mount_nodev(fs_type, flags, data, coda_fill_super); 323 } 324 325 struct file_system_type coda_fs_type = { 326 .owner = THIS_MODULE, 327 .name = "coda", 328 .mount = coda_mount, 329 .kill_sb = kill_anon_super, 330 .fs_flags = FS_BINARY_MOUNTDATA, 331 }; 332 MODULE_ALIAS_FS("coda"); 333 334