11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) 31da177e4SLinus Torvalds * Licensed under the GPL 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Ported the filesystem routines to 2.5. 61da177e4SLinus Torvalds * 2003-02-10 Petr Baudis <pasky@ucw.cz> 71da177e4SLinus Torvalds */ 81da177e4SLinus Torvalds 91da177e4SLinus Torvalds #include <linux/stddef.h> 101da177e4SLinus Torvalds #include <linux/fs.h> 111da177e4SLinus Torvalds #include <linux/version.h> 121da177e4SLinus Torvalds #include <linux/module.h> 131da177e4SLinus Torvalds #include <linux/init.h> 141da177e4SLinus Torvalds #include <linux/slab.h> 151da177e4SLinus Torvalds #include <linux/pagemap.h> 161da177e4SLinus Torvalds #include <linux/blkdev.h> 171da177e4SLinus Torvalds #include <linux/list.h> 181da177e4SLinus Torvalds #include <linux/root_dev.h> 191da177e4SLinus Torvalds #include <linux/statfs.h> 201da177e4SLinus Torvalds #include <linux/kdev_t.h> 211da177e4SLinus Torvalds #include <asm/uaccess.h> 221da177e4SLinus Torvalds #include "hostfs.h" 231da177e4SLinus Torvalds #include "kern_util.h" 241da177e4SLinus Torvalds #include "kern.h" 251da177e4SLinus Torvalds #include "user_util.h" 261da177e4SLinus Torvalds #include "2_5compat.h" 271da177e4SLinus Torvalds #include "init.h" 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds struct hostfs_inode_info { 301da177e4SLinus Torvalds char *host_filename; 311da177e4SLinus Torvalds int fd; 321da177e4SLinus Torvalds int mode; 331da177e4SLinus Torvalds struct inode vfs_inode; 341da177e4SLinus Torvalds }; 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 371da177e4SLinus Torvalds { 381da177e4SLinus Torvalds return(list_entry(inode, struct hostfs_inode_info, vfs_inode)); 391da177e4SLinus Torvalds } 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_dentry->d_inode) 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds int hostfs_d_delete(struct dentry *dentry) 441da177e4SLinus Torvalds { 451da177e4SLinus Torvalds return(1); 461da177e4SLinus Torvalds } 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds struct dentry_operations hostfs_dentry_ops = { 491da177e4SLinus Torvalds .d_delete = hostfs_d_delete, 501da177e4SLinus Torvalds }; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 531da177e4SLinus Torvalds static char *root_ino = "/"; 541da177e4SLinus Torvalds static int append = 0; 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds #define HOSTFS_SUPER_MAGIC 0x00c0ffee 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds static struct inode_operations hostfs_iops; 591da177e4SLinus Torvalds static struct inode_operations hostfs_dir_iops; 601da177e4SLinus Torvalds static struct address_space_operations hostfs_link_aops; 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds #ifndef MODULE 631da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 641da177e4SLinus Torvalds { 651da177e4SLinus Torvalds char *ptr; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds ptr = strchr(options, ','); 681da177e4SLinus Torvalds if(ptr != NULL) 691da177e4SLinus Torvalds *ptr++ = '\0'; 701da177e4SLinus Torvalds if(*options != '\0') 711da177e4SLinus Torvalds root_ino = options; 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds options = ptr; 741da177e4SLinus Torvalds while(options){ 751da177e4SLinus Torvalds ptr = strchr(options, ','); 761da177e4SLinus Torvalds if(ptr != NULL) 771da177e4SLinus Torvalds *ptr++ = '\0'; 781da177e4SLinus Torvalds if(*options != '\0'){ 791da177e4SLinus Torvalds if(!strcmp(options, "append")) 801da177e4SLinus Torvalds append = 1; 811da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 821da177e4SLinus Torvalds options); 831da177e4SLinus Torvalds } 841da177e4SLinus Torvalds options = ptr; 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds return(0); 871da177e4SLinus Torvalds } 881da177e4SLinus Torvalds 891da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 901da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 911da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 921da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 931da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 941da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 951da177e4SLinus Torvalds " it.\n" 961da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 971da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 981da177e4SLinus Torvalds ); 991da177e4SLinus Torvalds #endif 1001da177e4SLinus Torvalds 1011da177e4SLinus Torvalds static char *dentry_name(struct dentry *dentry, int extra) 1021da177e4SLinus Torvalds { 1031da177e4SLinus Torvalds struct dentry *parent; 1041da177e4SLinus Torvalds char *root, *name; 1051da177e4SLinus Torvalds int len; 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvalds len = 0; 1081da177e4SLinus Torvalds parent = dentry; 1091da177e4SLinus Torvalds while(parent->d_parent != parent){ 1101da177e4SLinus Torvalds len += parent->d_name.len + 1; 1111da177e4SLinus Torvalds parent = parent->d_parent; 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 1141da177e4SLinus Torvalds root = HOSTFS_I(parent->d_inode)->host_filename; 1151da177e4SLinus Torvalds len += strlen(root); 1161da177e4SLinus Torvalds name = kmalloc(len + extra + 1, GFP_KERNEL); 1171da177e4SLinus Torvalds if(name == NULL) return(NULL); 1181da177e4SLinus Torvalds 1191da177e4SLinus Torvalds name[len] = '\0'; 1201da177e4SLinus Torvalds parent = dentry; 1211da177e4SLinus Torvalds while(parent->d_parent != parent){ 1221da177e4SLinus Torvalds len -= parent->d_name.len + 1; 1231da177e4SLinus Torvalds name[len] = '/'; 1241da177e4SLinus Torvalds strncpy(&name[len + 1], parent->d_name.name, 1251da177e4SLinus Torvalds parent->d_name.len); 1261da177e4SLinus Torvalds parent = parent->d_parent; 1271da177e4SLinus Torvalds } 1281da177e4SLinus Torvalds strncpy(name, root, strlen(root)); 1291da177e4SLinus Torvalds return(name); 1301da177e4SLinus Torvalds } 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds static char *inode_name(struct inode *ino, int extra) 1331da177e4SLinus Torvalds { 1341da177e4SLinus Torvalds struct dentry *dentry; 1351da177e4SLinus Torvalds 1361da177e4SLinus Torvalds dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); 1371da177e4SLinus Torvalds return(dentry_name(dentry, extra)); 1381da177e4SLinus Torvalds } 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds static int read_name(struct inode *ino, char *name) 1411da177e4SLinus Torvalds { 1421da177e4SLinus Torvalds /* The non-int inode fields are copied into ints by stat_file and 1431da177e4SLinus Torvalds * then copied into the inode because passing the actual pointers 1441da177e4SLinus Torvalds * in and having them treated as int * breaks on big-endian machines 1451da177e4SLinus Torvalds */ 1461da177e4SLinus Torvalds int err; 1471da177e4SLinus Torvalds int i_mode, i_nlink, i_blksize; 1481da177e4SLinus Torvalds unsigned long long i_size; 1491da177e4SLinus Torvalds unsigned long long i_ino; 1501da177e4SLinus Torvalds unsigned long long i_blocks; 1511da177e4SLinus Torvalds 1521da177e4SLinus Torvalds err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, 1531da177e4SLinus Torvalds &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, 1541da177e4SLinus Torvalds &ino->i_ctime, &i_blksize, &i_blocks); 1551da177e4SLinus Torvalds if(err) 1561da177e4SLinus Torvalds return(err); 1571da177e4SLinus Torvalds 1581da177e4SLinus Torvalds ino->i_ino = i_ino; 1591da177e4SLinus Torvalds ino->i_mode = i_mode; 1601da177e4SLinus Torvalds ino->i_nlink = i_nlink; 1611da177e4SLinus Torvalds ino->i_size = i_size; 1621da177e4SLinus Torvalds ino->i_blksize = i_blksize; 1631da177e4SLinus Torvalds ino->i_blocks = i_blocks; 1641da177e4SLinus Torvalds if((ino->i_sb->s_dev == ROOT_DEV) && (ino->i_uid == getuid())) 1651da177e4SLinus Torvalds ino->i_uid = 0; 1661da177e4SLinus Torvalds return(0); 1671da177e4SLinus Torvalds } 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds static char *follow_link(char *link) 1701da177e4SLinus Torvalds { 1711da177e4SLinus Torvalds int len, n; 1721da177e4SLinus Torvalds char *name, *resolved, *end; 1731da177e4SLinus Torvalds 1741da177e4SLinus Torvalds len = 64; 1751da177e4SLinus Torvalds while(1){ 1761da177e4SLinus Torvalds n = -ENOMEM; 1771da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1781da177e4SLinus Torvalds if(name == NULL) 1791da177e4SLinus Torvalds goto out; 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds n = do_readlink(link, name, len); 1821da177e4SLinus Torvalds if(n < len) 1831da177e4SLinus Torvalds break; 1841da177e4SLinus Torvalds len *= 2; 1851da177e4SLinus Torvalds kfree(name); 1861da177e4SLinus Torvalds } 1871da177e4SLinus Torvalds if(n < 0) 1881da177e4SLinus Torvalds goto out_free; 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds if(*name == '/') 1911da177e4SLinus Torvalds return(name); 1921da177e4SLinus Torvalds 1931da177e4SLinus Torvalds end = strrchr(link, '/'); 1941da177e4SLinus Torvalds if(end == NULL) 1951da177e4SLinus Torvalds return(name); 1961da177e4SLinus Torvalds 1971da177e4SLinus Torvalds *(end + 1) = '\0'; 1981da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 2011da177e4SLinus Torvalds if(resolved == NULL){ 2021da177e4SLinus Torvalds n = -ENOMEM; 2031da177e4SLinus Torvalds goto out_free; 2041da177e4SLinus Torvalds } 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 2071da177e4SLinus Torvalds kfree(name); 2081da177e4SLinus Torvalds kfree(link); 2091da177e4SLinus Torvalds return(resolved); 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds out_free: 2121da177e4SLinus Torvalds kfree(name); 2131da177e4SLinus Torvalds out: 2141da177e4SLinus Torvalds return(ERR_PTR(n)); 2151da177e4SLinus Torvalds } 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds static int read_inode(struct inode *ino) 2181da177e4SLinus Torvalds { 2191da177e4SLinus Torvalds char *name; 2201da177e4SLinus Torvalds int err = 0; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds /* Unfortunately, we are called from iget() when we don't have a dentry 2231da177e4SLinus Torvalds * allocated yet. 2241da177e4SLinus Torvalds */ 2251da177e4SLinus Torvalds if(list_empty(&ino->i_dentry)) 2261da177e4SLinus Torvalds goto out; 2271da177e4SLinus Torvalds 2281da177e4SLinus Torvalds err = -ENOMEM; 2291da177e4SLinus Torvalds name = inode_name(ino, 0); 2301da177e4SLinus Torvalds if(name == NULL) 2311da177e4SLinus Torvalds goto out; 2321da177e4SLinus Torvalds 2331da177e4SLinus Torvalds if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){ 2341da177e4SLinus Torvalds name = follow_link(name); 2351da177e4SLinus Torvalds if(IS_ERR(name)){ 2361da177e4SLinus Torvalds err = PTR_ERR(name); 2371da177e4SLinus Torvalds goto out; 2381da177e4SLinus Torvalds } 2391da177e4SLinus Torvalds } 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvalds err = read_name(ino, name); 2421da177e4SLinus Torvalds kfree(name); 2431da177e4SLinus Torvalds out: 2441da177e4SLinus Torvalds return(err); 2451da177e4SLinus Torvalds } 2461da177e4SLinus Torvalds 2471da177e4SLinus Torvalds int hostfs_statfs(struct super_block *sb, struct kstatfs *sf) 2481da177e4SLinus Torvalds { 2491da177e4SLinus Torvalds /* do_statfs uses struct statfs64 internally, but the linux kernel 2501da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 2511da177e4SLinus Torvalds * so we convert them here 2521da177e4SLinus Torvalds */ 2531da177e4SLinus Torvalds int err; 2541da177e4SLinus Torvalds long long f_blocks; 2551da177e4SLinus Torvalds long long f_bfree; 2561da177e4SLinus Torvalds long long f_bavail; 2571da177e4SLinus Torvalds long long f_files; 2581da177e4SLinus Torvalds long long f_ffree; 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds err = do_statfs(HOSTFS_I(sb->s_root->d_inode)->host_filename, 2611da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2621da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2631da177e4SLinus Torvalds &sf->f_namelen, sf->f_spare); 2641da177e4SLinus Torvalds if(err) return(err); 2651da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2661da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2671da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2681da177e4SLinus Torvalds sf->f_files = f_files; 2691da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2701da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 2711da177e4SLinus Torvalds return(0); 2721da177e4SLinus Torvalds } 2731da177e4SLinus Torvalds 2741da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2751da177e4SLinus Torvalds { 2761da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds hi = kmalloc(sizeof(*hi), GFP_KERNEL); 2791da177e4SLinus Torvalds if(hi == NULL) 2801da177e4SLinus Torvalds return(NULL); 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds *hi = ((struct hostfs_inode_info) { .host_filename = NULL, 2831da177e4SLinus Torvalds .fd = -1, 2841da177e4SLinus Torvalds .mode = 0 }); 2851da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 2861da177e4SLinus Torvalds return(&hi->vfs_inode); 2871da177e4SLinus Torvalds } 2881da177e4SLinus Torvalds 2891da177e4SLinus Torvalds static void hostfs_delete_inode(struct inode *inode) 2901da177e4SLinus Torvalds { 2911da177e4SLinus Torvalds if(HOSTFS_I(inode)->fd != -1) { 2921da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2931da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds clear_inode(inode); 2961da177e4SLinus Torvalds } 2971da177e4SLinus Torvalds 2981da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2991da177e4SLinus Torvalds { 3001da177e4SLinus Torvalds if(HOSTFS_I(inode)->host_filename) 3011da177e4SLinus Torvalds kfree(HOSTFS_I(inode)->host_filename); 3021da177e4SLinus Torvalds 3031da177e4SLinus Torvalds /*XXX: This should not happen, probably. The check is here for 3041da177e4SLinus Torvalds * additional safety.*/ 3051da177e4SLinus Torvalds if(HOSTFS_I(inode)->fd != -1) { 3061da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 3071da177e4SLinus Torvalds printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); 3081da177e4SLinus Torvalds } 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds kfree(HOSTFS_I(inode)); 3111da177e4SLinus Torvalds } 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds static void hostfs_read_inode(struct inode *inode) 3141da177e4SLinus Torvalds { 3151da177e4SLinus Torvalds read_inode(inode); 3161da177e4SLinus Torvalds } 3171da177e4SLinus Torvalds 3181da177e4SLinus Torvalds static struct super_operations hostfs_sbops = { 3191da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 3201da177e4SLinus Torvalds .drop_inode = generic_delete_inode, 3211da177e4SLinus Torvalds .delete_inode = hostfs_delete_inode, 3221da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 3231da177e4SLinus Torvalds .read_inode = hostfs_read_inode, 3241da177e4SLinus Torvalds .statfs = hostfs_statfs, 3251da177e4SLinus Torvalds }; 3261da177e4SLinus Torvalds 3271da177e4SLinus Torvalds int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) 3281da177e4SLinus Torvalds { 3291da177e4SLinus Torvalds void *dir; 3301da177e4SLinus Torvalds char *name; 3311da177e4SLinus Torvalds unsigned long long next, ino; 3321da177e4SLinus Torvalds int error, len; 3331da177e4SLinus Torvalds 3341da177e4SLinus Torvalds name = dentry_name(file->f_dentry, 0); 3351da177e4SLinus Torvalds if(name == NULL) return(-ENOMEM); 3361da177e4SLinus Torvalds dir = open_dir(name, &error); 3371da177e4SLinus Torvalds kfree(name); 3381da177e4SLinus Torvalds if(dir == NULL) return(-error); 3391da177e4SLinus Torvalds next = file->f_pos; 3401da177e4SLinus Torvalds while((name = read_dir(dir, &next, &ino, &len)) != NULL){ 3411da177e4SLinus Torvalds error = (*filldir)(ent, name, len, file->f_pos, 3421da177e4SLinus Torvalds ino, DT_UNKNOWN); 3431da177e4SLinus Torvalds if(error) break; 3441da177e4SLinus Torvalds file->f_pos = next; 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds close_dir(dir); 3471da177e4SLinus Torvalds return(0); 3481da177e4SLinus Torvalds } 3491da177e4SLinus Torvalds 3501da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 3511da177e4SLinus Torvalds { 3521da177e4SLinus Torvalds char *name; 3531da177e4SLinus Torvalds int mode = 0, r = 0, w = 0, fd; 3541da177e4SLinus Torvalds 3551da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3561da177e4SLinus Torvalds if((mode & HOSTFS_I(ino)->mode) == mode) 3571da177e4SLinus Torvalds return(0); 3581da177e4SLinus Torvalds 3591da177e4SLinus Torvalds /* The file may already have been opened, but with the wrong access, 3601da177e4SLinus Torvalds * so this resets things and reopens the file with the new access. 3611da177e4SLinus Torvalds */ 3621da177e4SLinus Torvalds if(HOSTFS_I(ino)->fd != -1){ 3631da177e4SLinus Torvalds close_file(&HOSTFS_I(ino)->fd); 3641da177e4SLinus Torvalds HOSTFS_I(ino)->fd = -1; 3651da177e4SLinus Torvalds } 3661da177e4SLinus Torvalds 3671da177e4SLinus Torvalds HOSTFS_I(ino)->mode |= mode; 3681da177e4SLinus Torvalds if(HOSTFS_I(ino)->mode & FMODE_READ) 3691da177e4SLinus Torvalds r = 1; 3701da177e4SLinus Torvalds if(HOSTFS_I(ino)->mode & FMODE_WRITE) 3711da177e4SLinus Torvalds w = 1; 3721da177e4SLinus Torvalds if(w) 3731da177e4SLinus Torvalds r = 1; 3741da177e4SLinus Torvalds 3751da177e4SLinus Torvalds name = dentry_name(file->f_dentry, 0); 3761da177e4SLinus Torvalds if(name == NULL) 3771da177e4SLinus Torvalds return(-ENOMEM); 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds fd = open_file(name, r, w, append); 3801da177e4SLinus Torvalds kfree(name); 3811da177e4SLinus Torvalds if(fd < 0) return(fd); 3821da177e4SLinus Torvalds FILE_HOSTFS_I(file)->fd = fd; 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvalds return(0); 3851da177e4SLinus Torvalds } 3861da177e4SLinus Torvalds 3871da177e4SLinus Torvalds int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) 3881da177e4SLinus Torvalds { 3891da177e4SLinus Torvalds return(0); 3901da177e4SLinus Torvalds } 3911da177e4SLinus Torvalds 3921da177e4SLinus Torvalds static struct file_operations hostfs_file_fops = { 3931da177e4SLinus Torvalds .llseek = generic_file_llseek, 3941da177e4SLinus Torvalds .read = generic_file_read, 3951da177e4SLinus Torvalds .sendfile = generic_file_sendfile, 3961da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3971da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 3981da177e4SLinus Torvalds .readv = generic_file_readv, 3991da177e4SLinus Torvalds .writev = generic_file_writev, 4001da177e4SLinus Torvalds .write = generic_file_write, 4011da177e4SLinus Torvalds .mmap = generic_file_mmap, 4021da177e4SLinus Torvalds .open = hostfs_file_open, 4031da177e4SLinus Torvalds .release = NULL, 4041da177e4SLinus Torvalds .fsync = hostfs_fsync, 4051da177e4SLinus Torvalds }; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds static struct file_operations hostfs_dir_fops = { 4081da177e4SLinus Torvalds .llseek = generic_file_llseek, 4091da177e4SLinus Torvalds .readdir = hostfs_readdir, 4101da177e4SLinus Torvalds .read = generic_read_dir, 4111da177e4SLinus Torvalds }; 4121da177e4SLinus Torvalds 4131da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4141da177e4SLinus Torvalds { 4151da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4161da177e4SLinus Torvalds struct inode *inode = mapping->host; 4171da177e4SLinus Torvalds char *buffer; 4181da177e4SLinus Torvalds unsigned long long base; 4191da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 4201da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 4211da177e4SLinus Torvalds int err; 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds if (page->index >= end_index) 4241da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 4251da177e4SLinus Torvalds 4261da177e4SLinus Torvalds buffer = kmap(page); 4271da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 4281da177e4SLinus Torvalds 4291da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4301da177e4SLinus Torvalds if(err != count){ 4311da177e4SLinus Torvalds ClearPageUptodate(page); 4321da177e4SLinus Torvalds goto out; 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds 4351da177e4SLinus Torvalds if (base > inode->i_size) 4361da177e4SLinus Torvalds inode->i_size = base; 4371da177e4SLinus Torvalds 4381da177e4SLinus Torvalds if (PageError(page)) 4391da177e4SLinus Torvalds ClearPageError(page); 4401da177e4SLinus Torvalds err = 0; 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds out: 4431da177e4SLinus Torvalds kunmap(page); 4441da177e4SLinus Torvalds 4451da177e4SLinus Torvalds unlock_page(page); 4461da177e4SLinus Torvalds return err; 4471da177e4SLinus Torvalds } 4481da177e4SLinus Torvalds 4491da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4501da177e4SLinus Torvalds { 4511da177e4SLinus Torvalds char *buffer; 4521da177e4SLinus Torvalds long long start; 4531da177e4SLinus Torvalds int err = 0; 4541da177e4SLinus Torvalds 4551da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4561da177e4SLinus Torvalds buffer = kmap(page); 4571da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4581da177e4SLinus Torvalds PAGE_CACHE_SIZE); 4591da177e4SLinus Torvalds if(err < 0) goto out; 4601da177e4SLinus Torvalds 4611da177e4SLinus Torvalds memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); 4621da177e4SLinus Torvalds 4631da177e4SLinus Torvalds flush_dcache_page(page); 4641da177e4SLinus Torvalds SetPageUptodate(page); 4651da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 4661da177e4SLinus Torvalds err = 0; 4671da177e4SLinus Torvalds out: 4681da177e4SLinus Torvalds kunmap(page); 4691da177e4SLinus Torvalds unlock_page(page); 4701da177e4SLinus Torvalds return(err); 4711da177e4SLinus Torvalds } 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds int hostfs_prepare_write(struct file *file, struct page *page, 4741da177e4SLinus Torvalds unsigned int from, unsigned int to) 4751da177e4SLinus Torvalds { 4761da177e4SLinus Torvalds char *buffer; 4771da177e4SLinus Torvalds long long start, tmp; 4781da177e4SLinus Torvalds int err; 4791da177e4SLinus Torvalds 4801da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4811da177e4SLinus Torvalds buffer = kmap(page); 4821da177e4SLinus Torvalds if(from != 0){ 4831da177e4SLinus Torvalds tmp = start; 4841da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer, 4851da177e4SLinus Torvalds from); 4861da177e4SLinus Torvalds if(err < 0) goto out; 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds if(to != PAGE_CACHE_SIZE){ 4891da177e4SLinus Torvalds start += to; 4901da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to, 4911da177e4SLinus Torvalds PAGE_CACHE_SIZE - to); 4921da177e4SLinus Torvalds if(err < 0) goto out; 4931da177e4SLinus Torvalds } 4941da177e4SLinus Torvalds err = 0; 4951da177e4SLinus Torvalds out: 4961da177e4SLinus Torvalds kunmap(page); 4971da177e4SLinus Torvalds return(err); 4981da177e4SLinus Torvalds } 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds int hostfs_commit_write(struct file *file, struct page *page, unsigned from, 5011da177e4SLinus Torvalds unsigned to) 5021da177e4SLinus Torvalds { 5031da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 5041da177e4SLinus Torvalds struct inode *inode = mapping->host; 5051da177e4SLinus Torvalds char *buffer; 5061da177e4SLinus Torvalds long long start; 5071da177e4SLinus Torvalds int err = 0; 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds start = (long long) (page->index << PAGE_CACHE_SHIFT) + from; 5101da177e4SLinus Torvalds buffer = kmap(page); 5111da177e4SLinus Torvalds err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from, 5121da177e4SLinus Torvalds to - from); 5131da177e4SLinus Torvalds if(err > 0) err = 0; 5141da177e4SLinus Torvalds if(!err && (start > inode->i_size)) 5151da177e4SLinus Torvalds inode->i_size = start; 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds kunmap(page); 5181da177e4SLinus Torvalds return(err); 5191da177e4SLinus Torvalds } 5201da177e4SLinus Torvalds 5211da177e4SLinus Torvalds static struct address_space_operations hostfs_aops = { 5221da177e4SLinus Torvalds .writepage = hostfs_writepage, 5231da177e4SLinus Torvalds .readpage = hostfs_readpage, 5241da177e4SLinus Torvalds /* .set_page_dirty = __set_page_dirty_nobuffers, */ 5251da177e4SLinus Torvalds .prepare_write = hostfs_prepare_write, 5261da177e4SLinus Torvalds .commit_write = hostfs_commit_write 5271da177e4SLinus Torvalds }; 5281da177e4SLinus Torvalds 5291da177e4SLinus Torvalds static int init_inode(struct inode *inode, struct dentry *dentry) 5301da177e4SLinus Torvalds { 5311da177e4SLinus Torvalds char *name; 5321da177e4SLinus Torvalds int type, err = -ENOMEM; 5331da177e4SLinus Torvalds int maj, min; 5341da177e4SLinus Torvalds dev_t rdev = 0; 5351da177e4SLinus Torvalds 5361da177e4SLinus Torvalds if(dentry){ 5371da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5381da177e4SLinus Torvalds if(name == NULL) 5391da177e4SLinus Torvalds goto out; 5401da177e4SLinus Torvalds type = file_type(name, &maj, &min); 5411da177e4SLinus Torvalds /*Reencode maj and min with the kernel encoding.*/ 5421da177e4SLinus Torvalds rdev = MKDEV(maj, min); 5431da177e4SLinus Torvalds kfree(name); 5441da177e4SLinus Torvalds } 5451da177e4SLinus Torvalds else type = OS_TYPE_DIR; 5461da177e4SLinus Torvalds 5471da177e4SLinus Torvalds err = 0; 5481da177e4SLinus Torvalds if(type == OS_TYPE_SYMLINK) 5491da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations; 5501da177e4SLinus Torvalds else if(type == OS_TYPE_DIR) 5511da177e4SLinus Torvalds inode->i_op = &hostfs_dir_iops; 5521da177e4SLinus Torvalds else inode->i_op = &hostfs_iops; 5531da177e4SLinus Torvalds 5541da177e4SLinus Torvalds if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; 5551da177e4SLinus Torvalds else inode->i_fop = &hostfs_file_fops; 5561da177e4SLinus Torvalds 5571da177e4SLinus Torvalds if(type == OS_TYPE_SYMLINK) 5581da177e4SLinus Torvalds inode->i_mapping->a_ops = &hostfs_link_aops; 5591da177e4SLinus Torvalds else inode->i_mapping->a_ops = &hostfs_aops; 5601da177e4SLinus Torvalds 5611da177e4SLinus Torvalds switch (type) { 5621da177e4SLinus Torvalds case OS_TYPE_CHARDEV: 5631da177e4SLinus Torvalds init_special_inode(inode, S_IFCHR, rdev); 5641da177e4SLinus Torvalds break; 5651da177e4SLinus Torvalds case OS_TYPE_BLOCKDEV: 5661da177e4SLinus Torvalds init_special_inode(inode, S_IFBLK, rdev); 5671da177e4SLinus Torvalds break; 5681da177e4SLinus Torvalds case OS_TYPE_FIFO: 5691da177e4SLinus Torvalds init_special_inode(inode, S_IFIFO, 0); 5701da177e4SLinus Torvalds break; 5711da177e4SLinus Torvalds case OS_TYPE_SOCK: 5721da177e4SLinus Torvalds init_special_inode(inode, S_IFSOCK, 0); 5731da177e4SLinus Torvalds break; 5741da177e4SLinus Torvalds } 5751da177e4SLinus Torvalds out: 5761da177e4SLinus Torvalds return(err); 5771da177e4SLinus Torvalds } 5781da177e4SLinus Torvalds 5791da177e4SLinus Torvalds int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, 5801da177e4SLinus Torvalds struct nameidata *nd) 5811da177e4SLinus Torvalds { 5821da177e4SLinus Torvalds struct inode *inode; 5831da177e4SLinus Torvalds char *name; 5841da177e4SLinus Torvalds int error, fd; 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds error = -ENOMEM; 5871da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 5881da177e4SLinus Torvalds if(inode == NULL) goto out; 5891da177e4SLinus Torvalds 5901da177e4SLinus Torvalds error = init_inode(inode, dentry); 5911da177e4SLinus Torvalds if(error) 5921da177e4SLinus Torvalds goto out_put; 5931da177e4SLinus Torvalds 5941da177e4SLinus Torvalds error = -ENOMEM; 5951da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5961da177e4SLinus Torvalds if(name == NULL) 5971da177e4SLinus Torvalds goto out_put; 5981da177e4SLinus Torvalds 5991da177e4SLinus Torvalds fd = file_create(name, 6001da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 6011da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 6021da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 6031da177e4SLinus Torvalds if(fd < 0) 6041da177e4SLinus Torvalds error = fd; 6051da177e4SLinus Torvalds else error = read_name(inode, name); 6061da177e4SLinus Torvalds 6071da177e4SLinus Torvalds kfree(name); 6081da177e4SLinus Torvalds if(error) 6091da177e4SLinus Torvalds goto out_put; 6101da177e4SLinus Torvalds 6111da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 6121da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 6131da177e4SLinus Torvalds d_instantiate(dentry, inode); 6141da177e4SLinus Torvalds return(0); 6151da177e4SLinus Torvalds 6161da177e4SLinus Torvalds out_put: 6171da177e4SLinus Torvalds iput(inode); 6181da177e4SLinus Torvalds out: 6191da177e4SLinus Torvalds return(error); 6201da177e4SLinus Torvalds } 6211da177e4SLinus Torvalds 6221da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 6231da177e4SLinus Torvalds struct nameidata *nd) 6241da177e4SLinus Torvalds { 6251da177e4SLinus Torvalds struct inode *inode; 6261da177e4SLinus Torvalds char *name; 6271da177e4SLinus Torvalds int err; 6281da177e4SLinus Torvalds 6291da177e4SLinus Torvalds err = -ENOMEM; 6301da177e4SLinus Torvalds inode = iget(ino->i_sb, 0); 6311da177e4SLinus Torvalds if(inode == NULL) 6321da177e4SLinus Torvalds goto out; 6331da177e4SLinus Torvalds 6341da177e4SLinus Torvalds err = init_inode(inode, dentry); 6351da177e4SLinus Torvalds if(err) 6361da177e4SLinus Torvalds goto out_put; 6371da177e4SLinus Torvalds 6381da177e4SLinus Torvalds err = -ENOMEM; 6391da177e4SLinus Torvalds name = dentry_name(dentry, 0); 6401da177e4SLinus Torvalds if(name == NULL) 6411da177e4SLinus Torvalds goto out_put; 6421da177e4SLinus Torvalds 6431da177e4SLinus Torvalds err = read_name(inode, name); 6441da177e4SLinus Torvalds kfree(name); 6451da177e4SLinus Torvalds if(err == -ENOENT){ 6461da177e4SLinus Torvalds iput(inode); 6471da177e4SLinus Torvalds inode = NULL; 6481da177e4SLinus Torvalds } 6491da177e4SLinus Torvalds else if(err) 6501da177e4SLinus Torvalds goto out_put; 6511da177e4SLinus Torvalds 6521da177e4SLinus Torvalds d_add(dentry, inode); 6531da177e4SLinus Torvalds dentry->d_op = &hostfs_dentry_ops; 6541da177e4SLinus Torvalds return(NULL); 6551da177e4SLinus Torvalds 6561da177e4SLinus Torvalds out_put: 6571da177e4SLinus Torvalds iput(inode); 6581da177e4SLinus Torvalds out: 6591da177e4SLinus Torvalds return(ERR_PTR(err)); 6601da177e4SLinus Torvalds } 6611da177e4SLinus Torvalds 6621da177e4SLinus Torvalds static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) 6631da177e4SLinus Torvalds { 6641da177e4SLinus Torvalds char *file; 6651da177e4SLinus Torvalds int len; 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds file = inode_name(ino, dentry->d_name.len + 1); 6681da177e4SLinus Torvalds if(file == NULL) return(NULL); 6691da177e4SLinus Torvalds strcat(file, "/"); 6701da177e4SLinus Torvalds len = strlen(file); 6711da177e4SLinus Torvalds strncat(file, dentry->d_name.name, dentry->d_name.len); 6721da177e4SLinus Torvalds file[len + dentry->d_name.len] = '\0'; 6731da177e4SLinus Torvalds return(file); 6741da177e4SLinus Torvalds } 6751da177e4SLinus Torvalds 6761da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6771da177e4SLinus Torvalds { 6781da177e4SLinus Torvalds char *from_name, *to_name; 6791da177e4SLinus Torvalds int err; 6801da177e4SLinus Torvalds 6811da177e4SLinus Torvalds if((from_name = inode_dentry_name(ino, from)) == NULL) 6821da177e4SLinus Torvalds return(-ENOMEM); 6831da177e4SLinus Torvalds to_name = dentry_name(to, 0); 6841da177e4SLinus Torvalds if(to_name == NULL){ 6851da177e4SLinus Torvalds kfree(from_name); 6861da177e4SLinus Torvalds return(-ENOMEM); 6871da177e4SLinus Torvalds } 6881da177e4SLinus Torvalds err = link_file(to_name, from_name); 6891da177e4SLinus Torvalds kfree(from_name); 6901da177e4SLinus Torvalds kfree(to_name); 6911da177e4SLinus Torvalds return(err); 6921da177e4SLinus Torvalds } 6931da177e4SLinus Torvalds 6941da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6951da177e4SLinus Torvalds { 6961da177e4SLinus Torvalds char *file; 6971da177e4SLinus Torvalds int err; 6981da177e4SLinus Torvalds 6991da177e4SLinus Torvalds if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); 7001da177e4SLinus Torvalds if(append) 7011da177e4SLinus Torvalds return(-EPERM); 7021da177e4SLinus Torvalds 7031da177e4SLinus Torvalds err = unlink_file(file); 7041da177e4SLinus Torvalds kfree(file); 7051da177e4SLinus Torvalds return(err); 7061da177e4SLinus Torvalds } 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 7091da177e4SLinus Torvalds { 7101da177e4SLinus Torvalds char *file; 7111da177e4SLinus Torvalds int err; 7121da177e4SLinus Torvalds 7131da177e4SLinus Torvalds if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); 7141da177e4SLinus Torvalds err = make_symlink(file, to); 7151da177e4SLinus Torvalds kfree(file); 7161da177e4SLinus Torvalds return(err); 7171da177e4SLinus Torvalds } 7181da177e4SLinus Torvalds 7191da177e4SLinus Torvalds int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) 7201da177e4SLinus Torvalds { 7211da177e4SLinus Torvalds char *file; 7221da177e4SLinus Torvalds int err; 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); 7251da177e4SLinus Torvalds err = do_mkdir(file, mode); 7261da177e4SLinus Torvalds kfree(file); 7271da177e4SLinus Torvalds return(err); 7281da177e4SLinus Torvalds } 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 7311da177e4SLinus Torvalds { 7321da177e4SLinus Torvalds char *file; 7331da177e4SLinus Torvalds int err; 7341da177e4SLinus Torvalds 7351da177e4SLinus Torvalds if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); 7361da177e4SLinus Torvalds err = do_rmdir(file); 7371da177e4SLinus Torvalds kfree(file); 7381da177e4SLinus Torvalds return(err); 7391da177e4SLinus Torvalds } 7401da177e4SLinus Torvalds 7411da177e4SLinus Torvalds int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 7421da177e4SLinus Torvalds { 7431da177e4SLinus Torvalds struct inode *inode; 7441da177e4SLinus Torvalds char *name; 7451da177e4SLinus Torvalds int err = -ENOMEM; 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 7481da177e4SLinus Torvalds if(inode == NULL) 7491da177e4SLinus Torvalds goto out; 7501da177e4SLinus Torvalds 7511da177e4SLinus Torvalds err = init_inode(inode, dentry); 7521da177e4SLinus Torvalds if(err) 7531da177e4SLinus Torvalds goto out_put; 7541da177e4SLinus Torvalds 7551da177e4SLinus Torvalds err = -ENOMEM; 7561da177e4SLinus Torvalds name = dentry_name(dentry, 0); 7571da177e4SLinus Torvalds if(name == NULL) 7581da177e4SLinus Torvalds goto out_put; 7591da177e4SLinus Torvalds 7601da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 7611da177e4SLinus Torvalds err = do_mknod(name, mode, dev); 7621da177e4SLinus Torvalds if(err) 7631da177e4SLinus Torvalds goto out_free; 7641da177e4SLinus Torvalds 7651da177e4SLinus Torvalds err = read_name(inode, name); 7661da177e4SLinus Torvalds kfree(name); 7671da177e4SLinus Torvalds if(err) 7681da177e4SLinus Torvalds goto out_put; 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds d_instantiate(dentry, inode); 7711da177e4SLinus Torvalds return(0); 7721da177e4SLinus Torvalds 7731da177e4SLinus Torvalds out_free: 7741da177e4SLinus Torvalds kfree(name); 7751da177e4SLinus Torvalds out_put: 7761da177e4SLinus Torvalds iput(inode); 7771da177e4SLinus Torvalds out: 7781da177e4SLinus Torvalds return(err); 7791da177e4SLinus Torvalds } 7801da177e4SLinus Torvalds 7811da177e4SLinus Torvalds int hostfs_rename(struct inode *from_ino, struct dentry *from, 7821da177e4SLinus Torvalds struct inode *to_ino, struct dentry *to) 7831da177e4SLinus Torvalds { 7841da177e4SLinus Torvalds char *from_name, *to_name; 7851da177e4SLinus Torvalds int err; 7861da177e4SLinus Torvalds 7871da177e4SLinus Torvalds if((from_name = inode_dentry_name(from_ino, from)) == NULL) 7881da177e4SLinus Torvalds return(-ENOMEM); 7891da177e4SLinus Torvalds if((to_name = inode_dentry_name(to_ino, to)) == NULL){ 7901da177e4SLinus Torvalds kfree(from_name); 7911da177e4SLinus Torvalds return(-ENOMEM); 7921da177e4SLinus Torvalds } 7931da177e4SLinus Torvalds err = rename_file(from_name, to_name); 7941da177e4SLinus Torvalds kfree(from_name); 7951da177e4SLinus Torvalds kfree(to_name); 7961da177e4SLinus Torvalds return(err); 7971da177e4SLinus Torvalds } 7981da177e4SLinus Torvalds 7991da177e4SLinus Torvalds void hostfs_truncate(struct inode *ino) 8001da177e4SLinus Torvalds { 8011da177e4SLinus Torvalds not_implemented(); 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds 8041da177e4SLinus Torvalds int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) 8051da177e4SLinus Torvalds { 8061da177e4SLinus Torvalds char *name; 8071da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 8081da177e4SLinus Torvalds 8091da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 8101da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 8111da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 8121da177e4SLinus Torvalds name = inode_name(ino, 0); 8131da177e4SLinus Torvalds if (name == NULL) return(-ENOMEM); 8141da177e4SLinus Torvalds 8151da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 8161da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 8171da177e4SLinus Torvalds err = 0; 8181da177e4SLinus Torvalds else 8191da177e4SLinus Torvalds err = access_file(name, r, w, x); 8201da177e4SLinus Torvalds kfree(name); 8211da177e4SLinus Torvalds if(!err) 8221da177e4SLinus Torvalds err = generic_permission(ino, desired, NULL); 8231da177e4SLinus Torvalds return err; 8241da177e4SLinus Torvalds } 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 8271da177e4SLinus Torvalds { 8281da177e4SLinus Torvalds struct hostfs_iattr attrs; 8291da177e4SLinus Torvalds char *name; 8301da177e4SLinus Torvalds int err; 8311da177e4SLinus Torvalds 8321da177e4SLinus Torvalds err = inode_change_ok(dentry->d_inode, attr); 8331da177e4SLinus Torvalds if (err) 8341da177e4SLinus Torvalds return err; 8351da177e4SLinus Torvalds 8361da177e4SLinus Torvalds if(append) 8371da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8381da177e4SLinus Torvalds 8391da177e4SLinus Torvalds attrs.ia_valid = 0; 8401da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MODE){ 8411da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8421da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8431da177e4SLinus Torvalds } 8441da177e4SLinus Torvalds if(attr->ia_valid & ATTR_UID){ 8451da177e4SLinus Torvalds if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) && 8461da177e4SLinus Torvalds (attr->ia_uid == 0)) 8471da177e4SLinus Torvalds attr->ia_uid = getuid(); 8481da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 8491da177e4SLinus Torvalds attrs.ia_uid = attr->ia_uid; 8501da177e4SLinus Torvalds } 8511da177e4SLinus Torvalds if(attr->ia_valid & ATTR_GID){ 8521da177e4SLinus Torvalds if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) && 8531da177e4SLinus Torvalds (attr->ia_gid == 0)) 8541da177e4SLinus Torvalds attr->ia_gid = getgid(); 8551da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 8561da177e4SLinus Torvalds attrs.ia_gid = attr->ia_gid; 8571da177e4SLinus Torvalds } 8581da177e4SLinus Torvalds if(attr->ia_valid & ATTR_SIZE){ 8591da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8601da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8611da177e4SLinus Torvalds } 8621da177e4SLinus Torvalds if(attr->ia_valid & ATTR_ATIME){ 8631da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8641da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8651da177e4SLinus Torvalds } 8661da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MTIME){ 8671da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8681da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8691da177e4SLinus Torvalds } 8701da177e4SLinus Torvalds if(attr->ia_valid & ATTR_CTIME){ 8711da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8721da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 8731da177e4SLinus Torvalds } 8741da177e4SLinus Torvalds if(attr->ia_valid & ATTR_ATIME_SET){ 8751da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8761da177e4SLinus Torvalds } 8771da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MTIME_SET){ 8781da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8791da177e4SLinus Torvalds } 8801da177e4SLinus Torvalds name = dentry_name(dentry, 0); 8811da177e4SLinus Torvalds if(name == NULL) return(-ENOMEM); 8821da177e4SLinus Torvalds err = set_attr(name, &attrs); 8831da177e4SLinus Torvalds kfree(name); 8841da177e4SLinus Torvalds if(err) 8851da177e4SLinus Torvalds return(err); 8861da177e4SLinus Torvalds 8871da177e4SLinus Torvalds return(inode_setattr(dentry->d_inode, attr)); 8881da177e4SLinus Torvalds } 8891da177e4SLinus Torvalds 8901da177e4SLinus Torvalds int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 8911da177e4SLinus Torvalds struct kstat *stat) 8921da177e4SLinus Torvalds { 8931da177e4SLinus Torvalds generic_fillattr(dentry->d_inode, stat); 8941da177e4SLinus Torvalds return(0); 8951da177e4SLinus Torvalds } 8961da177e4SLinus Torvalds 8971da177e4SLinus Torvalds static struct inode_operations hostfs_iops = { 8981da177e4SLinus Torvalds .create = hostfs_create, 8991da177e4SLinus Torvalds .link = hostfs_link, 9001da177e4SLinus Torvalds .unlink = hostfs_unlink, 9011da177e4SLinus Torvalds .symlink = hostfs_symlink, 9021da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 9031da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 9041da177e4SLinus Torvalds .mknod = hostfs_mknod, 9051da177e4SLinus Torvalds .rename = hostfs_rename, 9061da177e4SLinus Torvalds .truncate = hostfs_truncate, 9071da177e4SLinus Torvalds .permission = hostfs_permission, 9081da177e4SLinus Torvalds .setattr = hostfs_setattr, 9091da177e4SLinus Torvalds .getattr = hostfs_getattr, 9101da177e4SLinus Torvalds }; 9111da177e4SLinus Torvalds 9121da177e4SLinus Torvalds static struct inode_operations hostfs_dir_iops = { 9131da177e4SLinus Torvalds .create = hostfs_create, 9141da177e4SLinus Torvalds .lookup = hostfs_lookup, 9151da177e4SLinus Torvalds .link = hostfs_link, 9161da177e4SLinus Torvalds .unlink = hostfs_unlink, 9171da177e4SLinus Torvalds .symlink = hostfs_symlink, 9181da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 9191da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 9201da177e4SLinus Torvalds .mknod = hostfs_mknod, 9211da177e4SLinus Torvalds .rename = hostfs_rename, 9221da177e4SLinus Torvalds .truncate = hostfs_truncate, 9231da177e4SLinus Torvalds .permission = hostfs_permission, 9241da177e4SLinus Torvalds .setattr = hostfs_setattr, 9251da177e4SLinus Torvalds .getattr = hostfs_getattr, 9261da177e4SLinus Torvalds }; 9271da177e4SLinus Torvalds 9281da177e4SLinus Torvalds int hostfs_link_readpage(struct file *file, struct page *page) 9291da177e4SLinus Torvalds { 9301da177e4SLinus Torvalds char *buffer, *name; 9311da177e4SLinus Torvalds long long start; 9321da177e4SLinus Torvalds int err; 9331da177e4SLinus Torvalds 9341da177e4SLinus Torvalds start = page->index << PAGE_CACHE_SHIFT; 9351da177e4SLinus Torvalds buffer = kmap(page); 9361da177e4SLinus Torvalds name = inode_name(page->mapping->host, 0); 9371da177e4SLinus Torvalds if(name == NULL) return(-ENOMEM); 9381da177e4SLinus Torvalds err = do_readlink(name, buffer, PAGE_CACHE_SIZE); 9391da177e4SLinus Torvalds kfree(name); 9401da177e4SLinus Torvalds if(err == PAGE_CACHE_SIZE) 9411da177e4SLinus Torvalds err = -E2BIG; 9421da177e4SLinus Torvalds else if(err > 0){ 9431da177e4SLinus Torvalds flush_dcache_page(page); 9441da177e4SLinus Torvalds SetPageUptodate(page); 9451da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 9461da177e4SLinus Torvalds err = 0; 9471da177e4SLinus Torvalds } 9481da177e4SLinus Torvalds kunmap(page); 9491da177e4SLinus Torvalds unlock_page(page); 9501da177e4SLinus Torvalds return(err); 9511da177e4SLinus Torvalds } 9521da177e4SLinus Torvalds 9531da177e4SLinus Torvalds static struct address_space_operations hostfs_link_aops = { 9541da177e4SLinus Torvalds .readpage = hostfs_link_readpage, 9551da177e4SLinus Torvalds }; 9561da177e4SLinus Torvalds 9571da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9581da177e4SLinus Torvalds { 9591da177e4SLinus Torvalds struct inode *root_inode; 9601da177e4SLinus Torvalds char *name, *data = d; 9611da177e4SLinus Torvalds int err; 9621da177e4SLinus Torvalds 9631da177e4SLinus Torvalds sb->s_blocksize = 1024; 9641da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9651da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9661da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 9671da177e4SLinus Torvalds 9681da177e4SLinus Torvalds if((data == NULL) || (*data == '\0')) 9691da177e4SLinus Torvalds data = root_ino; 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds err = -ENOMEM; 9721da177e4SLinus Torvalds name = kmalloc(strlen(data) + 1, GFP_KERNEL); 9731da177e4SLinus Torvalds if(name == NULL) 9741da177e4SLinus Torvalds goto out; 9751da177e4SLinus Torvalds 9761da177e4SLinus Torvalds strcpy(name, data); 9771da177e4SLinus Torvalds 9781da177e4SLinus Torvalds root_inode = iget(sb, 0); 9791da177e4SLinus Torvalds if(root_inode == NULL) 9801da177e4SLinus Torvalds goto out_free; 9811da177e4SLinus Torvalds 9821da177e4SLinus Torvalds err = init_inode(root_inode, NULL); 9831da177e4SLinus Torvalds if(err) 9841da177e4SLinus Torvalds goto out_put; 9851da177e4SLinus Torvalds 9861da177e4SLinus Torvalds HOSTFS_I(root_inode)->host_filename = name; 9871da177e4SLinus Torvalds 9881da177e4SLinus Torvalds err = -ENOMEM; 9891da177e4SLinus Torvalds sb->s_root = d_alloc_root(root_inode); 9901da177e4SLinus Torvalds if(sb->s_root == NULL) 9911da177e4SLinus Torvalds goto out_put; 9921da177e4SLinus Torvalds 9931da177e4SLinus Torvalds err = read_inode(root_inode); 9941da177e4SLinus Torvalds if(err) 9951da177e4SLinus Torvalds goto out_put; 9961da177e4SLinus Torvalds 9971da177e4SLinus Torvalds return(0); 9981da177e4SLinus Torvalds 9991da177e4SLinus Torvalds out_put: 10001da177e4SLinus Torvalds iput(root_inode); 10011da177e4SLinus Torvalds out_free: 10021da177e4SLinus Torvalds kfree(name); 10031da177e4SLinus Torvalds out: 10041da177e4SLinus Torvalds return(err); 10051da177e4SLinus Torvalds } 10061da177e4SLinus Torvalds 10071da177e4SLinus Torvalds static struct super_block *hostfs_read_sb(struct file_system_type *type, 10081da177e4SLinus Torvalds int flags, const char *dev_name, 10091da177e4SLinus Torvalds void *data) 10101da177e4SLinus Torvalds { 10111da177e4SLinus Torvalds return(get_sb_nodev(type, flags, data, hostfs_fill_sb_common)); 10121da177e4SLinus Torvalds } 10131da177e4SLinus Torvalds 10141da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 10151da177e4SLinus Torvalds .owner = THIS_MODULE, 10161da177e4SLinus Torvalds .name = "hostfs", 10171da177e4SLinus Torvalds .get_sb = hostfs_read_sb, 10181da177e4SLinus Torvalds .kill_sb = kill_anon_super, 10191da177e4SLinus Torvalds .fs_flags = 0, 10201da177e4SLinus Torvalds }; 10211da177e4SLinus Torvalds 10221da177e4SLinus Torvalds static int __init init_hostfs(void) 10231da177e4SLinus Torvalds { 10241da177e4SLinus Torvalds return(register_filesystem(&hostfs_type)); 10251da177e4SLinus Torvalds } 10261da177e4SLinus Torvalds 10271da177e4SLinus Torvalds static void __exit exit_hostfs(void) 10281da177e4SLinus Torvalds { 10291da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 10301da177e4SLinus Torvalds } 10311da177e4SLinus Torvalds 10321da177e4SLinus Torvalds module_init(init_hostfs) 10331da177e4SLinus Torvalds module_exit(exit_hostfs) 10341da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 10351da177e4SLinus Torvalds 10361da177e4SLinus Torvalds /* 10371da177e4SLinus Torvalds * Overrides for Emacs so that we follow Linus's tabbing style. 10381da177e4SLinus Torvalds * Emacs will notice this stuff at the end of the file and automatically 10391da177e4SLinus Torvalds * adjust the settings for this buffer only. This must remain at the end 10401da177e4SLinus Torvalds * of the file. 10411da177e4SLinus Torvalds * --------------------------------------------------------------------------- 10421da177e4SLinus Torvalds * Local variables: 10431da177e4SLinus Torvalds * c-file-style: "linux" 10441da177e4SLinus Torvalds * End: 10451da177e4SLinus Torvalds */ 1046