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 24 #include <asm/uaccess.h> 25 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 = 0; 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 coda_init_inodecache(void) 76 { 77 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 78 sizeof(struct coda_inode_info), 79 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 80 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 *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 printk("coda_read_super: Bad mount data\n"); 121 return -1; 122 } 123 124 if (data->version != CODA_MOUNT_VERSION) { 125 printk("coda_read_super: Bad mount version\n"); 126 return -1; 127 } 128 129 f = fdget(data->fd); 130 if (!f.file) 131 goto Ebadf; 132 inode = f.file->f_path.dentry->d_inode; 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 printk("coda_read_super: Bad minor number\n"); 143 return -1; 144 } 145 146 return idx; 147 Ebadf: 148 printk("coda_read_super: Bad file\n"); 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 idx = get_device_index((struct coda_mount_data *) data); 161 162 /* Ignore errors in data, for backward compatibility */ 163 if(idx == -1) 164 idx = 0; 165 166 printk(KERN_INFO "coda_read_super: device index: %i\n", idx); 167 168 vc = &coda_comms[idx]; 169 mutex_lock(&vc->vc_mutex); 170 171 if (!vc->vc_inuse) { 172 printk("coda_read_super: No pseudo device\n"); 173 error = -EINVAL; 174 goto unlock_out; 175 } 176 177 if (vc->vc_sb) { 178 printk("coda_read_super: Device already mounted\n"); 179 error = -EBUSY; 180 goto unlock_out; 181 } 182 183 error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY); 184 if (error) 185 goto unlock_out; 186 187 vc->vc_sb = sb; 188 mutex_unlock(&vc->vc_mutex); 189 190 sb->s_fs_info = vc; 191 sb->s_flags |= MS_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 sb->s_bdi = &vc->bdi; 198 199 /* get root fid from Venus: this needs the root inode */ 200 error = venus_rootfid(sb, &fid); 201 if ( error ) { 202 printk("coda_read_super: coda_get_rootfid failed with %d\n", 203 error); 204 goto error; 205 } 206 printk("coda_read_super: rootfid is %s\n", 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 printk("Failure of coda_cnode_make for root: error %d\n", error); 213 goto error; 214 } 215 216 printk("coda_read_super: rootinode is %ld dev %s\n", 217 root->i_ino, root->i_sb->s_id); 218 sb->s_root = d_make_root(root); 219 if (!sb->s_root) { 220 error = -EINVAL; 221 goto error; 222 } 223 return 0; 224 225 error: 226 mutex_lock(&vc->vc_mutex); 227 bdi_destroy(&vc->bdi); 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 bdi_destroy(&vcp->bdi); 240 vcp->vc_sb = NULL; 241 sb->s_fs_info = NULL; 242 mutex_unlock(&vcp->vc_mutex); 243 244 printk("Coda: Bye bye.\n"); 245 } 246 247 static void coda_evict_inode(struct inode *inode) 248 { 249 truncate_inode_pages(&inode->i_data, 0); 250 clear_inode(inode); 251 coda_cache_clear_inode(inode); 252 } 253 254 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 255 { 256 int err = coda_revalidate_inode(dentry); 257 if (!err) 258 generic_fillattr(dentry->d_inode, stat); 259 return err; 260 } 261 262 int coda_setattr(struct dentry *de, struct iattr *iattr) 263 { 264 struct inode *inode = de->d_inode; 265 struct coda_vattr vattr; 266 int error; 267 268 memset(&vattr, 0, sizeof(vattr)); 269 270 inode->i_ctime = CURRENT_TIME_SEC; 271 coda_iattr_to_vattr(iattr, &vattr); 272 vattr.va_type = C_VNON; /* cannot set type */ 273 274 /* Venus is responsible for truncating the container-file!!! */ 275 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); 276 277 if (!error) { 278 coda_vattr_to_iattr(inode, &vattr); 279 coda_cache_clear_inode(inode); 280 } 281 return error; 282 } 283 284 const struct inode_operations coda_file_inode_operations = { 285 .permission = coda_permission, 286 .getattr = coda_getattr, 287 .setattr = coda_setattr, 288 }; 289 290 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) 291 { 292 int error; 293 294 error = venus_statfs(dentry, buf); 295 296 if (error) { 297 /* fake something like AFS does */ 298 buf->f_blocks = 9000000; 299 buf->f_bfree = 9000000; 300 buf->f_bavail = 9000000; 301 buf->f_files = 9000000; 302 buf->f_ffree = 9000000; 303 } 304 305 /* and fill in the rest */ 306 buf->f_type = CODA_SUPER_MAGIC; 307 buf->f_bsize = 4096; 308 buf->f_namelen = CODA_MAXNAMLEN; 309 310 return 0; 311 } 312 313 /* init_coda: used by filesystems.c to register coda */ 314 315 static struct dentry *coda_mount(struct file_system_type *fs_type, 316 int flags, const char *dev_name, void *data) 317 { 318 return mount_nodev(fs_type, flags, data, coda_fill_super); 319 } 320 321 struct file_system_type coda_fs_type = { 322 .owner = THIS_MODULE, 323 .name = "coda", 324 .mount = coda_mount, 325 .kill_sb = kill_anon_super, 326 .fs_flags = FS_BINARY_MOUNTDATA, 327 }; 328 329