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 coda_alloc_inode(struct super_block * sb)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 coda_i_callback(struct rcu_head * head)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 coda_destroy_inode(struct inode * inode)62 static void coda_destroy_inode(struct inode *inode) 63 { 64 call_rcu(&inode->i_rcu, coda_i_callback); 65 } 66 init_once(void * foo)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 coda_init_inodecache(void)74 int __init coda_init_inodecache(void) 75 { 76 coda_inode_cachep = kmem_cache_create("coda_inode_cache", 77 sizeof(struct coda_inode_info), 78 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 79 init_once); 80 if (coda_inode_cachep == NULL) 81 return -ENOMEM; 82 return 0; 83 } 84 coda_destroy_inodecache(void)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 coda_remount(struct super_block * sb,int * flags,char * data)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 get_device_index(struct coda_mount_data * data)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 coda_fill_super(struct super_block * sb,void * data,int silent)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 error = bdi_setup_and_register(&vc->bdi, "coda"); 187 if (error) 188 goto unlock_out; 189 190 vc->vc_sb = sb; 191 mutex_unlock(&vc->vc_mutex); 192 193 sb->s_fs_info = vc; 194 sb->s_flags |= MS_NOATIME; 195 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ 196 sb->s_blocksize_bits = 12; 197 sb->s_magic = CODA_SUPER_MAGIC; 198 sb->s_op = &coda_super_operations; 199 sb->s_d_op = &coda_dentry_operations; 200 sb->s_bdi = &vc->bdi; 201 202 /* get root fid from Venus: this needs the root inode */ 203 error = venus_rootfid(sb, &fid); 204 if ( error ) { 205 pr_warn("%s: coda_get_rootfid failed with %d\n", 206 __func__, error); 207 goto error; 208 } 209 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); 210 211 /* make root inode */ 212 root = coda_cnode_make(&fid, sb); 213 if (IS_ERR(root)) { 214 error = PTR_ERR(root); 215 pr_warn("Failure of coda_cnode_make for root: error %d\n", 216 error); 217 goto error; 218 } 219 220 pr_info("%s: rootinode is %ld dev %s\n", 221 __func__, 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 coda_put_super(struct super_block * sb)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 pr_info("Bye bye.\n"); 249 } 250 coda_evict_inode(struct inode * inode)251 static void coda_evict_inode(struct inode *inode) 252 { 253 truncate_inode_pages_final(&inode->i_data); 254 clear_inode(inode); 255 coda_cache_clear_inode(inode); 256 } 257 coda_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)258 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 259 { 260 int err = coda_revalidate_inode(d_inode(dentry)); 261 if (!err) 262 generic_fillattr(d_inode(dentry), stat); 263 return err; 264 } 265 coda_setattr(struct dentry * de,struct iattr * iattr)266 int coda_setattr(struct dentry *de, struct iattr *iattr) 267 { 268 struct inode *inode = d_inode(de); 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 coda_statfs(struct dentry * dentry,struct kstatfs * buf)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 coda_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)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