11da177e4SLinus Torvalds /* 2f1adc05eSJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.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/module.h> 121da177e4SLinus Torvalds #include <linux/init.h> 131da177e4SLinus Torvalds #include <linux/slab.h> 141da177e4SLinus Torvalds #include <linux/pagemap.h> 151da177e4SLinus Torvalds #include <linux/blkdev.h> 161da177e4SLinus Torvalds #include <linux/list.h> 171da177e4SLinus Torvalds #include <linux/statfs.h> 181da177e4SLinus Torvalds #include <linux/kdev_t.h> 191da177e4SLinus Torvalds #include <asm/uaccess.h> 201da177e4SLinus Torvalds #include "hostfs.h" 211da177e4SLinus Torvalds #include "kern_util.h" 221da177e4SLinus Torvalds #include "kern.h" 231da177e4SLinus Torvalds #include "init.h" 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds struct hostfs_inode_info { 261da177e4SLinus Torvalds char *host_filename; 271da177e4SLinus Torvalds int fd; 281da177e4SLinus Torvalds int mode; 291da177e4SLinus Torvalds struct inode vfs_inode; 301da177e4SLinus Torvalds }; 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 331da177e4SLinus Torvalds { 34f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode); 351da177e4SLinus Torvalds } 361da177e4SLinus Torvalds 37680b0da9SJosef Sipek #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) 381da177e4SLinus Torvalds 391da177e4SLinus Torvalds int hostfs_d_delete(struct dentry *dentry) 401da177e4SLinus Torvalds { 41f1adc05eSJeff Dike return 1; 421da177e4SLinus Torvalds } 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds struct dentry_operations hostfs_dentry_ops = { 451da177e4SLinus Torvalds .d_delete = hostfs_d_delete, 461da177e4SLinus Torvalds }; 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 49a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 501da177e4SLinus Torvalds static int append = 0; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds #define HOSTFS_SUPER_MAGIC 0x00c0ffee 531da177e4SLinus Torvalds 5492e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 5592e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 56f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds #ifndef MODULE 591da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 601da177e4SLinus Torvalds { 611da177e4SLinus Torvalds char *ptr; 621da177e4SLinus Torvalds 631da177e4SLinus Torvalds ptr = strchr(options, ','); 641da177e4SLinus Torvalds if(ptr != NULL) 651da177e4SLinus Torvalds *ptr++ = '\0'; 661da177e4SLinus Torvalds if(*options != '\0') 671da177e4SLinus Torvalds root_ino = options; 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds options = ptr; 701da177e4SLinus Torvalds while(options){ 711da177e4SLinus Torvalds ptr = strchr(options, ','); 721da177e4SLinus Torvalds if(ptr != NULL) 731da177e4SLinus Torvalds *ptr++ = '\0'; 741da177e4SLinus Torvalds if(*options != '\0'){ 751da177e4SLinus Torvalds if(!strcmp(options, "append")) 761da177e4SLinus Torvalds append = 1; 771da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 781da177e4SLinus Torvalds options); 791da177e4SLinus Torvalds } 801da177e4SLinus Torvalds options = ptr; 811da177e4SLinus Torvalds } 82f1adc05eSJeff Dike return 0; 831da177e4SLinus Torvalds } 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 861da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 871da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 881da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 891da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 901da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 911da177e4SLinus Torvalds " it.\n" 921da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 931da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 941da177e4SLinus Torvalds ); 951da177e4SLinus Torvalds #endif 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds static char *dentry_name(struct dentry *dentry, int extra) 981da177e4SLinus Torvalds { 991da177e4SLinus Torvalds struct dentry *parent; 1001da177e4SLinus Torvalds char *root, *name; 1011da177e4SLinus Torvalds int len; 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds len = 0; 1041da177e4SLinus Torvalds parent = dentry; 1051da177e4SLinus Torvalds while(parent->d_parent != parent){ 1061da177e4SLinus Torvalds len += parent->d_name.len + 1; 1071da177e4SLinus Torvalds parent = parent->d_parent; 1081da177e4SLinus Torvalds } 1091da177e4SLinus Torvalds 1101da177e4SLinus Torvalds root = HOSTFS_I(parent->d_inode)->host_filename; 1111da177e4SLinus Torvalds len += strlen(root); 1121da177e4SLinus Torvalds name = kmalloc(len + extra + 1, GFP_KERNEL); 113f1adc05eSJeff Dike if(name == NULL) 114f1adc05eSJeff Dike return NULL; 1151da177e4SLinus Torvalds 1161da177e4SLinus Torvalds name[len] = '\0'; 1171da177e4SLinus Torvalds parent = dentry; 1181da177e4SLinus Torvalds while(parent->d_parent != parent){ 1191da177e4SLinus Torvalds len -= parent->d_name.len + 1; 1201da177e4SLinus Torvalds name[len] = '/'; 1211da177e4SLinus Torvalds strncpy(&name[len + 1], parent->d_name.name, 1221da177e4SLinus Torvalds parent->d_name.len); 1231da177e4SLinus Torvalds parent = parent->d_parent; 1241da177e4SLinus Torvalds } 1251da177e4SLinus Torvalds strncpy(name, root, strlen(root)); 126f1adc05eSJeff Dike return name; 1271da177e4SLinus Torvalds } 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvalds static char *inode_name(struct inode *ino, int extra) 1301da177e4SLinus Torvalds { 1311da177e4SLinus Torvalds struct dentry *dentry; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); 134f1adc05eSJeff Dike return dentry_name(dentry, extra); 1351da177e4SLinus Torvalds } 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds static int read_name(struct inode *ino, char *name) 1381da177e4SLinus Torvalds { 1391da177e4SLinus Torvalds /* The non-int inode fields are copied into ints by stat_file and 1401da177e4SLinus Torvalds * then copied into the inode because passing the actual pointers 1411da177e4SLinus Torvalds * in and having them treated as int * breaks on big-endian machines 1421da177e4SLinus Torvalds */ 1431da177e4SLinus Torvalds int err; 1441da177e4SLinus Torvalds int i_mode, i_nlink, i_blksize; 1451da177e4SLinus Torvalds unsigned long long i_size; 1461da177e4SLinus Torvalds unsigned long long i_ino; 1471da177e4SLinus Torvalds unsigned long long i_blocks; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, 1501da177e4SLinus Torvalds &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, 1515822b7faSAlberto Bertogli &ino->i_ctime, &i_blksize, &i_blocks, -1); 1521da177e4SLinus Torvalds if(err) 153f1adc05eSJeff Dike return err; 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds ino->i_ino = i_ino; 1561da177e4SLinus Torvalds ino->i_mode = i_mode; 1571da177e4SLinus Torvalds ino->i_nlink = i_nlink; 1581da177e4SLinus Torvalds ino->i_size = i_size; 1591da177e4SLinus Torvalds ino->i_blocks = i_blocks; 160f1adc05eSJeff Dike return 0; 1611da177e4SLinus Torvalds } 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds static char *follow_link(char *link) 1641da177e4SLinus Torvalds { 1651da177e4SLinus Torvalds int len, n; 1661da177e4SLinus Torvalds char *name, *resolved, *end; 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds len = 64; 1691da177e4SLinus Torvalds while(1){ 1701da177e4SLinus Torvalds n = -ENOMEM; 1711da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1721da177e4SLinus Torvalds if(name == NULL) 1731da177e4SLinus Torvalds goto out; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds n = do_readlink(link, name, len); 1761da177e4SLinus Torvalds if(n < len) 1771da177e4SLinus Torvalds break; 1781da177e4SLinus Torvalds len *= 2; 1791da177e4SLinus Torvalds kfree(name); 1801da177e4SLinus Torvalds } 1811da177e4SLinus Torvalds if(n < 0) 1821da177e4SLinus Torvalds goto out_free; 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds if(*name == '/') 185f1adc05eSJeff Dike return name; 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds end = strrchr(link, '/'); 1881da177e4SLinus Torvalds if(end == NULL) 189f1adc05eSJeff Dike return name; 1901da177e4SLinus Torvalds 1911da177e4SLinus Torvalds *(end + 1) = '\0'; 1921da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1931da177e4SLinus Torvalds 1941da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 1951da177e4SLinus Torvalds if(resolved == NULL){ 1961da177e4SLinus Torvalds n = -ENOMEM; 1971da177e4SLinus Torvalds goto out_free; 1981da177e4SLinus Torvalds } 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 2011da177e4SLinus Torvalds kfree(name); 2021da177e4SLinus Torvalds kfree(link); 203f1adc05eSJeff Dike return resolved; 2041da177e4SLinus Torvalds 2051da177e4SLinus Torvalds out_free: 2061da177e4SLinus Torvalds kfree(name); 2071da177e4SLinus Torvalds out: 208f1adc05eSJeff Dike return ERR_PTR(n); 2091da177e4SLinus Torvalds } 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds static int read_inode(struct inode *ino) 2121da177e4SLinus Torvalds { 2131da177e4SLinus Torvalds char *name; 2141da177e4SLinus Torvalds int err = 0; 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds /* Unfortunately, we are called from iget() when we don't have a dentry 2171da177e4SLinus Torvalds * allocated yet. 2181da177e4SLinus Torvalds */ 2191da177e4SLinus Torvalds if(list_empty(&ino->i_dentry)) 2201da177e4SLinus Torvalds goto out; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds err = -ENOMEM; 2231da177e4SLinus Torvalds name = inode_name(ino, 0); 2241da177e4SLinus Torvalds if(name == NULL) 2251da177e4SLinus Torvalds goto out; 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){ 2281da177e4SLinus Torvalds name = follow_link(name); 2291da177e4SLinus Torvalds if(IS_ERR(name)){ 2301da177e4SLinus Torvalds err = PTR_ERR(name); 2311da177e4SLinus Torvalds goto out; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds } 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds err = read_name(ino, name); 2361da177e4SLinus Torvalds kfree(name); 2371da177e4SLinus Torvalds out: 238f1adc05eSJeff Dike return err; 2391da177e4SLinus Torvalds } 2401da177e4SLinus Torvalds 241726c3342SDavid Howells int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 2421da177e4SLinus Torvalds { 2431da177e4SLinus Torvalds /* do_statfs uses struct statfs64 internally, but the linux kernel 2441da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 2451da177e4SLinus Torvalds * so we convert them here 2461da177e4SLinus Torvalds */ 2471da177e4SLinus Torvalds int err; 2481da177e4SLinus Torvalds long long f_blocks; 2491da177e4SLinus Torvalds long long f_bfree; 2501da177e4SLinus Torvalds long long f_bavail; 2511da177e4SLinus Torvalds long long f_files; 2521da177e4SLinus Torvalds long long f_ffree; 2531da177e4SLinus Torvalds 254726c3342SDavid Howells err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename, 2551da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2561da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2571da177e4SLinus Torvalds &sf->f_namelen, sf->f_spare); 258f1adc05eSJeff Dike if(err) 259f1adc05eSJeff Dike return err; 2601da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2611da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2621da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2631da177e4SLinus Torvalds sf->f_files = f_files; 2641da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2651da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 266f1adc05eSJeff Dike return 0; 2671da177e4SLinus Torvalds } 2681da177e4SLinus Torvalds 2691da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2701da177e4SLinus Torvalds { 2711da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds hi = kmalloc(sizeof(*hi), GFP_KERNEL); 2741da177e4SLinus Torvalds if(hi == NULL) 275f1adc05eSJeff Dike return NULL; 2761da177e4SLinus Torvalds 2771da177e4SLinus Torvalds *hi = ((struct hostfs_inode_info) { .host_filename = NULL, 2781da177e4SLinus Torvalds .fd = -1, 2791da177e4SLinus Torvalds .mode = 0 }); 2801da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 281f1adc05eSJeff Dike return &hi->vfs_inode; 2821da177e4SLinus Torvalds } 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds static void hostfs_delete_inode(struct inode *inode) 2851da177e4SLinus Torvalds { 286fef26658SMark Fasheh truncate_inode_pages(&inode->i_data, 0); 2871da177e4SLinus Torvalds if(HOSTFS_I(inode)->fd != -1) { 2881da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2891da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2901da177e4SLinus Torvalds } 2911da177e4SLinus Torvalds clear_inode(inode); 2921da177e4SLinus Torvalds } 2931da177e4SLinus Torvalds 2941da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2951da177e4SLinus Torvalds { 2961da177e4SLinus Torvalds kfree(HOSTFS_I(inode)->host_filename); 2971da177e4SLinus Torvalds 2981da177e4SLinus Torvalds /*XXX: This should not happen, probably. The check is here for 2991da177e4SLinus Torvalds * additional safety.*/ 3001da177e4SLinus Torvalds if(HOSTFS_I(inode)->fd != -1) { 3011da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 3021da177e4SLinus Torvalds printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds kfree(HOSTFS_I(inode)); 3061da177e4SLinus Torvalds } 3071da177e4SLinus Torvalds 3081da177e4SLinus Torvalds static void hostfs_read_inode(struct inode *inode) 3091da177e4SLinus Torvalds { 3101da177e4SLinus Torvalds read_inode(inode); 3111da177e4SLinus Torvalds } 3121da177e4SLinus Torvalds 313ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 3141da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 3151da177e4SLinus Torvalds .drop_inode = generic_delete_inode, 3161da177e4SLinus Torvalds .delete_inode = hostfs_delete_inode, 3171da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 3181da177e4SLinus Torvalds .read_inode = hostfs_read_inode, 3191da177e4SLinus Torvalds .statfs = hostfs_statfs, 3201da177e4SLinus Torvalds }; 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) 3231da177e4SLinus Torvalds { 3241da177e4SLinus Torvalds void *dir; 3251da177e4SLinus Torvalds char *name; 3261da177e4SLinus Torvalds unsigned long long next, ino; 3271da177e4SLinus Torvalds int error, len; 3281da177e4SLinus Torvalds 329680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 330f1adc05eSJeff Dike if(name == NULL) 331f1adc05eSJeff Dike return -ENOMEM; 3321da177e4SLinus Torvalds dir = open_dir(name, &error); 3331da177e4SLinus Torvalds kfree(name); 334f1adc05eSJeff Dike if(dir == NULL) 335f1adc05eSJeff Dike return -error; 3361da177e4SLinus Torvalds next = file->f_pos; 3371da177e4SLinus Torvalds while((name = read_dir(dir, &next, &ino, &len)) != NULL){ 3381da177e4SLinus Torvalds error = (*filldir)(ent, name, len, file->f_pos, 3391da177e4SLinus Torvalds ino, DT_UNKNOWN); 3401da177e4SLinus Torvalds if(error) break; 3411da177e4SLinus Torvalds file->f_pos = next; 3421da177e4SLinus Torvalds } 3431da177e4SLinus Torvalds close_dir(dir); 344f1adc05eSJeff Dike return 0; 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 3481da177e4SLinus Torvalds { 3491da177e4SLinus Torvalds char *name; 3501da177e4SLinus Torvalds int mode = 0, r = 0, w = 0, fd; 3511da177e4SLinus Torvalds 3521da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3531da177e4SLinus Torvalds if((mode & HOSTFS_I(ino)->mode) == mode) 354f1adc05eSJeff Dike return 0; 3551da177e4SLinus Torvalds 3561da177e4SLinus Torvalds /* The file may already have been opened, but with the wrong access, 3571da177e4SLinus Torvalds * so this resets things and reopens the file with the new access. 3581da177e4SLinus Torvalds */ 3591da177e4SLinus Torvalds if(HOSTFS_I(ino)->fd != -1){ 3601da177e4SLinus Torvalds close_file(&HOSTFS_I(ino)->fd); 3611da177e4SLinus Torvalds HOSTFS_I(ino)->fd = -1; 3621da177e4SLinus Torvalds } 3631da177e4SLinus Torvalds 3641da177e4SLinus Torvalds HOSTFS_I(ino)->mode |= mode; 3651da177e4SLinus Torvalds if(HOSTFS_I(ino)->mode & FMODE_READ) 3661da177e4SLinus Torvalds r = 1; 3671da177e4SLinus Torvalds if(HOSTFS_I(ino)->mode & FMODE_WRITE) 3681da177e4SLinus Torvalds w = 1; 3691da177e4SLinus Torvalds if(w) 3701da177e4SLinus Torvalds r = 1; 3711da177e4SLinus Torvalds 372680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 3731da177e4SLinus Torvalds if(name == NULL) 374f1adc05eSJeff Dike return -ENOMEM; 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds fd = open_file(name, r, w, append); 3771da177e4SLinus Torvalds kfree(name); 378f1adc05eSJeff Dike if(fd < 0) 379f1adc05eSJeff Dike return fd; 3801da177e4SLinus Torvalds FILE_HOSTFS_I(file)->fd = fd; 3811da177e4SLinus Torvalds 382f1adc05eSJeff Dike return 0; 3831da177e4SLinus Torvalds } 3841da177e4SLinus Torvalds 3851da177e4SLinus Torvalds int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) 3861da177e4SLinus Torvalds { 387a2d76bd8SPaolo 'Blaisorblade' Giarrusso return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); 3881da177e4SLinus Torvalds } 3891da177e4SLinus Torvalds 3904b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3911da177e4SLinus Torvalds .llseek = generic_file_llseek, 392543ade1fSBadari Pulavarty .read = do_sync_read, 3935ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3941da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3951da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 396543ade1fSBadari Pulavarty .write = do_sync_write, 3971da177e4SLinus Torvalds .mmap = generic_file_mmap, 3981da177e4SLinus Torvalds .open = hostfs_file_open, 3991da177e4SLinus Torvalds .release = NULL, 4001da177e4SLinus Torvalds .fsync = hostfs_fsync, 4011da177e4SLinus Torvalds }; 4021da177e4SLinus Torvalds 4034b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 4041da177e4SLinus Torvalds .llseek = generic_file_llseek, 4051da177e4SLinus Torvalds .readdir = hostfs_readdir, 4061da177e4SLinus Torvalds .read = generic_read_dir, 4071da177e4SLinus Torvalds }; 4081da177e4SLinus Torvalds 4091da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4101da177e4SLinus Torvalds { 4111da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4121da177e4SLinus Torvalds struct inode *inode = mapping->host; 4131da177e4SLinus Torvalds char *buffer; 4141da177e4SLinus Torvalds unsigned long long base; 4151da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 4161da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 4171da177e4SLinus Torvalds int err; 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds if (page->index >= end_index) 4201da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds buffer = kmap(page); 4231da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 4241da177e4SLinus Torvalds 4251da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4261da177e4SLinus Torvalds if(err != count){ 4271da177e4SLinus Torvalds ClearPageUptodate(page); 4281da177e4SLinus Torvalds goto out; 4291da177e4SLinus Torvalds } 4301da177e4SLinus Torvalds 4311da177e4SLinus Torvalds if (base > inode->i_size) 4321da177e4SLinus Torvalds inode->i_size = base; 4331da177e4SLinus Torvalds 4341da177e4SLinus Torvalds if (PageError(page)) 4351da177e4SLinus Torvalds ClearPageError(page); 4361da177e4SLinus Torvalds err = 0; 4371da177e4SLinus Torvalds 4381da177e4SLinus Torvalds out: 4391da177e4SLinus Torvalds kunmap(page); 4401da177e4SLinus Torvalds 4411da177e4SLinus Torvalds unlock_page(page); 4421da177e4SLinus Torvalds return err; 4431da177e4SLinus Torvalds } 4441da177e4SLinus Torvalds 4451da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4461da177e4SLinus Torvalds { 4471da177e4SLinus Torvalds char *buffer; 4481da177e4SLinus Torvalds long long start; 4491da177e4SLinus Torvalds int err = 0; 4501da177e4SLinus Torvalds 4511da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4521da177e4SLinus Torvalds buffer = kmap(page); 4531da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4541da177e4SLinus Torvalds PAGE_CACHE_SIZE); 4551da177e4SLinus Torvalds if(err < 0) goto out; 4561da177e4SLinus Torvalds 4571da177e4SLinus Torvalds memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); 4581da177e4SLinus Torvalds 4591da177e4SLinus Torvalds flush_dcache_page(page); 4601da177e4SLinus Torvalds SetPageUptodate(page); 4611da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 4621da177e4SLinus Torvalds err = 0; 4631da177e4SLinus Torvalds out: 4641da177e4SLinus Torvalds kunmap(page); 4651da177e4SLinus Torvalds unlock_page(page); 466f1adc05eSJeff Dike return err; 4671da177e4SLinus Torvalds } 4681da177e4SLinus Torvalds 469ae361ff4SNick Piggin int hostfs_write_begin(struct file *file, struct address_space *mapping, 470ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 471ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4721da177e4SLinus Torvalds { 473ae361ff4SNick Piggin pgoff_t index = pos >> PAGE_CACHE_SHIFT; 474ae361ff4SNick Piggin 475ae361ff4SNick Piggin *pagep = __grab_cache_page(mapping, index); 476ae361ff4SNick Piggin if (!*pagep) 477ae361ff4SNick Piggin return -ENOMEM; 478ae361ff4SNick Piggin return 0; 479ae361ff4SNick Piggin } 480ae361ff4SNick Piggin 481ae361ff4SNick Piggin int hostfs_write_end(struct file *file, struct address_space *mapping, 482ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 483ae361ff4SNick Piggin struct page *page, void *fsdata) 484ae361ff4SNick Piggin { 485ae361ff4SNick Piggin struct inode *inode = mapping->host; 486ae361ff4SNick Piggin void *buffer; 487ae361ff4SNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 4881da177e4SLinus Torvalds int err; 4891da177e4SLinus Torvalds 4901da177e4SLinus Torvalds buffer = kmap(page); 491ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4921da177e4SLinus Torvalds kunmap(page); 4931da177e4SLinus Torvalds 494ae361ff4SNick Piggin if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) 495ae361ff4SNick Piggin SetPageUptodate(page); 4961da177e4SLinus Torvalds 497ae361ff4SNick Piggin /* If err > 0, write_file has added err to pos, so we are comparing 498ae361ff4SNick Piggin * i_size against the last byte written. 499ae361ff4SNick Piggin */ 500ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 501ae361ff4SNick Piggin inode->i_size = pos; 502ae361ff4SNick Piggin unlock_page(page); 503ae361ff4SNick Piggin page_cache_release(page); 50430f04a4eSPaolo 'Blaisorblade' Giarrusso 505f1adc05eSJeff Dike return err; 5061da177e4SLinus Torvalds } 5071da177e4SLinus Torvalds 508f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 5091da177e4SLinus Torvalds .writepage = hostfs_writepage, 5101da177e4SLinus Torvalds .readpage = hostfs_readpage, 511ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 512ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 513ae361ff4SNick Piggin .write_end = hostfs_write_end, 5141da177e4SLinus Torvalds }; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds static int init_inode(struct inode *inode, struct dentry *dentry) 5171da177e4SLinus Torvalds { 5181da177e4SLinus Torvalds char *name; 5191da177e4SLinus Torvalds int type, err = -ENOMEM; 5201da177e4SLinus Torvalds int maj, min; 5211da177e4SLinus Torvalds dev_t rdev = 0; 5221da177e4SLinus Torvalds 5231da177e4SLinus Torvalds if(dentry){ 5241da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5251da177e4SLinus Torvalds if(name == NULL) 5261da177e4SLinus Torvalds goto out; 5271da177e4SLinus Torvalds type = file_type(name, &maj, &min); 5281da177e4SLinus Torvalds /*Reencode maj and min with the kernel encoding.*/ 5291da177e4SLinus Torvalds rdev = MKDEV(maj, min); 5301da177e4SLinus Torvalds kfree(name); 5311da177e4SLinus Torvalds } 5321da177e4SLinus Torvalds else type = OS_TYPE_DIR; 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds err = 0; 5351da177e4SLinus Torvalds if(type == OS_TYPE_SYMLINK) 5361da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations; 5371da177e4SLinus Torvalds else if(type == OS_TYPE_DIR) 5381da177e4SLinus Torvalds inode->i_op = &hostfs_dir_iops; 5391da177e4SLinus Torvalds else inode->i_op = &hostfs_iops; 5401da177e4SLinus Torvalds 5411da177e4SLinus Torvalds if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; 5421da177e4SLinus Torvalds else inode->i_fop = &hostfs_file_fops; 5431da177e4SLinus Torvalds 5441da177e4SLinus Torvalds if(type == OS_TYPE_SYMLINK) 5451da177e4SLinus Torvalds inode->i_mapping->a_ops = &hostfs_link_aops; 5461da177e4SLinus Torvalds else inode->i_mapping->a_ops = &hostfs_aops; 5471da177e4SLinus Torvalds 5481da177e4SLinus Torvalds switch (type) { 5491da177e4SLinus Torvalds case OS_TYPE_CHARDEV: 5501da177e4SLinus Torvalds init_special_inode(inode, S_IFCHR, rdev); 5511da177e4SLinus Torvalds break; 5521da177e4SLinus Torvalds case OS_TYPE_BLOCKDEV: 5531da177e4SLinus Torvalds init_special_inode(inode, S_IFBLK, rdev); 5541da177e4SLinus Torvalds break; 5551da177e4SLinus Torvalds case OS_TYPE_FIFO: 5561da177e4SLinus Torvalds init_special_inode(inode, S_IFIFO, 0); 5571da177e4SLinus Torvalds break; 5581da177e4SLinus Torvalds case OS_TYPE_SOCK: 5591da177e4SLinus Torvalds init_special_inode(inode, S_IFSOCK, 0); 5601da177e4SLinus Torvalds break; 5611da177e4SLinus Torvalds } 5621da177e4SLinus Torvalds out: 563f1adc05eSJeff Dike return err; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 5661da177e4SLinus Torvalds int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, 5671da177e4SLinus Torvalds struct nameidata *nd) 5681da177e4SLinus Torvalds { 5691da177e4SLinus Torvalds struct inode *inode; 5701da177e4SLinus Torvalds char *name; 5711da177e4SLinus Torvalds int error, fd; 5721da177e4SLinus Torvalds 5731da177e4SLinus Torvalds error = -ENOMEM; 5741da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 5751da177e4SLinus Torvalds if(inode == NULL) goto out; 5761da177e4SLinus Torvalds 5771da177e4SLinus Torvalds error = init_inode(inode, dentry); 5781da177e4SLinus Torvalds if(error) 5791da177e4SLinus Torvalds goto out_put; 5801da177e4SLinus Torvalds 5811da177e4SLinus Torvalds error = -ENOMEM; 5821da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5831da177e4SLinus Torvalds if(name == NULL) 5841da177e4SLinus Torvalds goto out_put; 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds fd = file_create(name, 5871da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 5881da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 5891da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 5901da177e4SLinus Torvalds if(fd < 0) 5911da177e4SLinus Torvalds error = fd; 5921da177e4SLinus Torvalds else error = read_name(inode, name); 5931da177e4SLinus Torvalds 5941da177e4SLinus Torvalds kfree(name); 5951da177e4SLinus Torvalds if(error) 5961da177e4SLinus Torvalds goto out_put; 5971da177e4SLinus Torvalds 5981da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5991da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 6001da177e4SLinus Torvalds d_instantiate(dentry, inode); 601f1adc05eSJeff Dike return 0; 6021da177e4SLinus Torvalds 6031da177e4SLinus Torvalds out_put: 6041da177e4SLinus Torvalds iput(inode); 6051da177e4SLinus Torvalds out: 606f1adc05eSJeff Dike return error; 6071da177e4SLinus Torvalds } 6081da177e4SLinus Torvalds 6091da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 6101da177e4SLinus Torvalds struct nameidata *nd) 6111da177e4SLinus Torvalds { 6121da177e4SLinus Torvalds struct inode *inode; 6131da177e4SLinus Torvalds char *name; 6141da177e4SLinus Torvalds int err; 6151da177e4SLinus Torvalds 6161da177e4SLinus Torvalds err = -ENOMEM; 6171da177e4SLinus Torvalds inode = iget(ino->i_sb, 0); 6181da177e4SLinus Torvalds if(inode == NULL) 6191da177e4SLinus Torvalds goto out; 6201da177e4SLinus Torvalds 6211da177e4SLinus Torvalds err = init_inode(inode, dentry); 6221da177e4SLinus Torvalds if(err) 6231da177e4SLinus Torvalds goto out_put; 6241da177e4SLinus Torvalds 6251da177e4SLinus Torvalds err = -ENOMEM; 6261da177e4SLinus Torvalds name = dentry_name(dentry, 0); 6271da177e4SLinus Torvalds if(name == NULL) 6281da177e4SLinus Torvalds goto out_put; 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds err = read_name(inode, name); 6311da177e4SLinus Torvalds kfree(name); 6321da177e4SLinus Torvalds if(err == -ENOENT){ 6331da177e4SLinus Torvalds iput(inode); 6341da177e4SLinus Torvalds inode = NULL; 6351da177e4SLinus Torvalds } 6361da177e4SLinus Torvalds else if(err) 6371da177e4SLinus Torvalds goto out_put; 6381da177e4SLinus Torvalds 6391da177e4SLinus Torvalds d_add(dentry, inode); 6401da177e4SLinus Torvalds dentry->d_op = &hostfs_dentry_ops; 641f1adc05eSJeff Dike return NULL; 6421da177e4SLinus Torvalds 6431da177e4SLinus Torvalds out_put: 6441da177e4SLinus Torvalds iput(inode); 6451da177e4SLinus Torvalds out: 646f1adc05eSJeff Dike return ERR_PTR(err); 6471da177e4SLinus Torvalds } 6481da177e4SLinus Torvalds 6491da177e4SLinus Torvalds static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) 6501da177e4SLinus Torvalds { 6511da177e4SLinus Torvalds char *file; 6521da177e4SLinus Torvalds int len; 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds file = inode_name(ino, dentry->d_name.len + 1); 655f1adc05eSJeff Dike if(file == NULL) 656f1adc05eSJeff Dike return NULL; 6571da177e4SLinus Torvalds strcat(file, "/"); 6581da177e4SLinus Torvalds len = strlen(file); 6591da177e4SLinus Torvalds strncat(file, dentry->d_name.name, dentry->d_name.len); 6601da177e4SLinus Torvalds file[len + dentry->d_name.len] = '\0'; 661f1adc05eSJeff Dike return file; 6621da177e4SLinus Torvalds } 6631da177e4SLinus Torvalds 6641da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6651da177e4SLinus Torvalds { 6661da177e4SLinus Torvalds char *from_name, *to_name; 6671da177e4SLinus Torvalds int err; 6681da177e4SLinus Torvalds 6691da177e4SLinus Torvalds if((from_name = inode_dentry_name(ino, from)) == NULL) 670f1adc05eSJeff Dike return -ENOMEM; 6711da177e4SLinus Torvalds to_name = dentry_name(to, 0); 6721da177e4SLinus Torvalds if(to_name == NULL){ 6731da177e4SLinus Torvalds kfree(from_name); 674f1adc05eSJeff Dike return -ENOMEM; 6751da177e4SLinus Torvalds } 6761da177e4SLinus Torvalds err = link_file(to_name, from_name); 6771da177e4SLinus Torvalds kfree(from_name); 6781da177e4SLinus Torvalds kfree(to_name); 679f1adc05eSJeff Dike return err; 6801da177e4SLinus Torvalds } 6811da177e4SLinus Torvalds 6821da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6831da177e4SLinus Torvalds { 6841da177e4SLinus Torvalds char *file; 6851da177e4SLinus Torvalds int err; 6861da177e4SLinus Torvalds 687f1adc05eSJeff Dike if((file = inode_dentry_name(ino, dentry)) == NULL) 688f1adc05eSJeff Dike return -ENOMEM; 6891da177e4SLinus Torvalds if(append) 690f1adc05eSJeff Dike return -EPERM; 6911da177e4SLinus Torvalds 6921da177e4SLinus Torvalds err = unlink_file(file); 6931da177e4SLinus Torvalds kfree(file); 694f1adc05eSJeff Dike return err; 6951da177e4SLinus Torvalds } 6961da177e4SLinus Torvalds 6971da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 6981da177e4SLinus Torvalds { 6991da177e4SLinus Torvalds char *file; 7001da177e4SLinus Torvalds int err; 7011da177e4SLinus Torvalds 702f1adc05eSJeff Dike if((file = inode_dentry_name(ino, dentry)) == NULL) 703f1adc05eSJeff Dike return -ENOMEM; 7041da177e4SLinus Torvalds err = make_symlink(file, to); 7051da177e4SLinus Torvalds kfree(file); 706f1adc05eSJeff Dike return err; 7071da177e4SLinus Torvalds } 7081da177e4SLinus Torvalds 7091da177e4SLinus Torvalds int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) 7101da177e4SLinus Torvalds { 7111da177e4SLinus Torvalds char *file; 7121da177e4SLinus Torvalds int err; 7131da177e4SLinus Torvalds 714f1adc05eSJeff Dike if((file = inode_dentry_name(ino, dentry)) == NULL) 715f1adc05eSJeff Dike return -ENOMEM; 7161da177e4SLinus Torvalds err = do_mkdir(file, mode); 7171da177e4SLinus Torvalds kfree(file); 718f1adc05eSJeff Dike return err; 7191da177e4SLinus Torvalds } 7201da177e4SLinus Torvalds 7211da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 7221da177e4SLinus Torvalds { 7231da177e4SLinus Torvalds char *file; 7241da177e4SLinus Torvalds int err; 7251da177e4SLinus Torvalds 726f1adc05eSJeff Dike if((file = inode_dentry_name(ino, dentry)) == NULL) 727f1adc05eSJeff Dike return -ENOMEM; 7281da177e4SLinus Torvalds err = do_rmdir(file); 7291da177e4SLinus Torvalds kfree(file); 730f1adc05eSJeff Dike return err; 7311da177e4SLinus Torvalds } 7321da177e4SLinus Torvalds 7331da177e4SLinus Torvalds int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 7341da177e4SLinus Torvalds { 7351da177e4SLinus Torvalds struct inode *inode; 7361da177e4SLinus Torvalds char *name; 7371da177e4SLinus Torvalds int err = -ENOMEM; 7381da177e4SLinus Torvalds 7391da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 7401da177e4SLinus Torvalds if(inode == NULL) 7411da177e4SLinus Torvalds goto out; 7421da177e4SLinus Torvalds 7431da177e4SLinus Torvalds err = init_inode(inode, dentry); 7441da177e4SLinus Torvalds if(err) 7451da177e4SLinus Torvalds goto out_put; 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds err = -ENOMEM; 7481da177e4SLinus Torvalds name = dentry_name(dentry, 0); 7491da177e4SLinus Torvalds if(name == NULL) 7501da177e4SLinus Torvalds goto out_put; 7511da177e4SLinus Torvalds 7521da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 75388f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 7541da177e4SLinus Torvalds if(err) 7551da177e4SLinus Torvalds goto out_free; 7561da177e4SLinus Torvalds 7571da177e4SLinus Torvalds err = read_name(inode, name); 7581da177e4SLinus Torvalds kfree(name); 7591da177e4SLinus Torvalds if(err) 7601da177e4SLinus Torvalds goto out_put; 7611da177e4SLinus Torvalds 7621da177e4SLinus Torvalds d_instantiate(dentry, inode); 763f1adc05eSJeff Dike return 0; 7641da177e4SLinus Torvalds 7651da177e4SLinus Torvalds out_free: 7661da177e4SLinus Torvalds kfree(name); 7671da177e4SLinus Torvalds out_put: 7681da177e4SLinus Torvalds iput(inode); 7691da177e4SLinus Torvalds out: 770f1adc05eSJeff Dike return err; 7711da177e4SLinus Torvalds } 7721da177e4SLinus Torvalds 7731da177e4SLinus Torvalds int hostfs_rename(struct inode *from_ino, struct dentry *from, 7741da177e4SLinus Torvalds struct inode *to_ino, struct dentry *to) 7751da177e4SLinus Torvalds { 7761da177e4SLinus Torvalds char *from_name, *to_name; 7771da177e4SLinus Torvalds int err; 7781da177e4SLinus Torvalds 7791da177e4SLinus Torvalds if((from_name = inode_dentry_name(from_ino, from)) == NULL) 780f1adc05eSJeff Dike return -ENOMEM; 7811da177e4SLinus Torvalds if((to_name = inode_dentry_name(to_ino, to)) == NULL){ 7821da177e4SLinus Torvalds kfree(from_name); 783f1adc05eSJeff Dike return -ENOMEM; 7841da177e4SLinus Torvalds } 7851da177e4SLinus Torvalds err = rename_file(from_name, to_name); 7861da177e4SLinus Torvalds kfree(from_name); 7871da177e4SLinus Torvalds kfree(to_name); 788f1adc05eSJeff Dike return err; 7891da177e4SLinus Torvalds } 7901da177e4SLinus Torvalds 7911da177e4SLinus Torvalds int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) 7921da177e4SLinus Torvalds { 7931da177e4SLinus Torvalds char *name; 7941da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7951da177e4SLinus Torvalds 7961da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7971da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7981da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 7991da177e4SLinus Torvalds name = inode_name(ino, 0); 800f1adc05eSJeff Dike if (name == NULL) 801f1adc05eSJeff Dike return -ENOMEM; 8021da177e4SLinus Torvalds 8031da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 8041da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 8051da177e4SLinus Torvalds err = 0; 8061da177e4SLinus Torvalds else 8071da177e4SLinus Torvalds err = access_file(name, r, w, x); 8081da177e4SLinus Torvalds kfree(name); 8091da177e4SLinus Torvalds if(!err) 8101da177e4SLinus Torvalds err = generic_permission(ino, desired, NULL); 8111da177e4SLinus Torvalds return err; 8121da177e4SLinus Torvalds } 8131da177e4SLinus Torvalds 8141da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 8151da177e4SLinus Torvalds { 8161da177e4SLinus Torvalds struct hostfs_iattr attrs; 8171da177e4SLinus Torvalds char *name; 8181da177e4SLinus Torvalds int err; 8191da177e4SLinus Torvalds 8205822b7faSAlberto Bertogli int fd = HOSTFS_I(dentry->d_inode)->fd; 8215822b7faSAlberto Bertogli 8221da177e4SLinus Torvalds err = inode_change_ok(dentry->d_inode, attr); 8231da177e4SLinus Torvalds if (err) 8241da177e4SLinus Torvalds return err; 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds if(append) 8271da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8281da177e4SLinus Torvalds 8291da177e4SLinus Torvalds attrs.ia_valid = 0; 8301da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MODE){ 8311da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8321da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8331da177e4SLinus Torvalds } 8341da177e4SLinus Torvalds if(attr->ia_valid & ATTR_UID){ 8351da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 8361da177e4SLinus Torvalds attrs.ia_uid = attr->ia_uid; 8371da177e4SLinus Torvalds } 8381da177e4SLinus Torvalds if(attr->ia_valid & ATTR_GID){ 8391da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 8401da177e4SLinus Torvalds attrs.ia_gid = attr->ia_gid; 8411da177e4SLinus Torvalds } 8421da177e4SLinus Torvalds if(attr->ia_valid & ATTR_SIZE){ 8431da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8441da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8451da177e4SLinus Torvalds } 8461da177e4SLinus Torvalds if(attr->ia_valid & ATTR_ATIME){ 8471da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8481da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8491da177e4SLinus Torvalds } 8501da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MTIME){ 8511da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8521da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8531da177e4SLinus Torvalds } 8541da177e4SLinus Torvalds if(attr->ia_valid & ATTR_CTIME){ 8551da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8561da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 8571da177e4SLinus Torvalds } 8581da177e4SLinus Torvalds if(attr->ia_valid & ATTR_ATIME_SET){ 8591da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8601da177e4SLinus Torvalds } 8611da177e4SLinus Torvalds if(attr->ia_valid & ATTR_MTIME_SET){ 8621da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8631da177e4SLinus Torvalds } 8641da177e4SLinus Torvalds name = dentry_name(dentry, 0); 865f1adc05eSJeff Dike if(name == NULL) 866f1adc05eSJeff Dike return -ENOMEM; 8675822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 8681da177e4SLinus Torvalds kfree(name); 8691da177e4SLinus Torvalds if(err) 870f1adc05eSJeff Dike return err; 8711da177e4SLinus Torvalds 872f1adc05eSJeff Dike return inode_setattr(dentry->d_inode, attr); 8731da177e4SLinus Torvalds } 8741da177e4SLinus Torvalds 8751da177e4SLinus Torvalds int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 8761da177e4SLinus Torvalds struct kstat *stat) 8771da177e4SLinus Torvalds { 8781da177e4SLinus Torvalds generic_fillattr(dentry->d_inode, stat); 879f1adc05eSJeff Dike return 0; 8801da177e4SLinus Torvalds } 8811da177e4SLinus Torvalds 88292e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8831da177e4SLinus Torvalds .create = hostfs_create, 8841da177e4SLinus Torvalds .link = hostfs_link, 8851da177e4SLinus Torvalds .unlink = hostfs_unlink, 8861da177e4SLinus Torvalds .symlink = hostfs_symlink, 8871da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8881da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8891da177e4SLinus Torvalds .mknod = hostfs_mknod, 8901da177e4SLinus Torvalds .rename = hostfs_rename, 8911da177e4SLinus Torvalds .permission = hostfs_permission, 8921da177e4SLinus Torvalds .setattr = hostfs_setattr, 8931da177e4SLinus Torvalds .getattr = hostfs_getattr, 8941da177e4SLinus Torvalds }; 8951da177e4SLinus Torvalds 89692e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8971da177e4SLinus Torvalds .create = hostfs_create, 8981da177e4SLinus Torvalds .lookup = hostfs_lookup, 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 .permission = hostfs_permission, 9071da177e4SLinus Torvalds .setattr = hostfs_setattr, 9081da177e4SLinus Torvalds .getattr = hostfs_getattr, 9091da177e4SLinus Torvalds }; 9101da177e4SLinus Torvalds 9111da177e4SLinus Torvalds int hostfs_link_readpage(struct file *file, struct page *page) 9121da177e4SLinus Torvalds { 9131da177e4SLinus Torvalds char *buffer, *name; 9141da177e4SLinus Torvalds int err; 9151da177e4SLinus Torvalds 9161da177e4SLinus Torvalds buffer = kmap(page); 9171da177e4SLinus Torvalds name = inode_name(page->mapping->host, 0); 918f1adc05eSJeff Dike if(name == NULL) 919f1adc05eSJeff Dike return -ENOMEM; 9201da177e4SLinus Torvalds err = do_readlink(name, buffer, PAGE_CACHE_SIZE); 9211da177e4SLinus Torvalds kfree(name); 9221da177e4SLinus Torvalds if(err == PAGE_CACHE_SIZE) 9231da177e4SLinus Torvalds err = -E2BIG; 9241da177e4SLinus Torvalds else if(err > 0){ 9251da177e4SLinus Torvalds flush_dcache_page(page); 9261da177e4SLinus Torvalds SetPageUptodate(page); 9271da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 9281da177e4SLinus Torvalds err = 0; 9291da177e4SLinus Torvalds } 9301da177e4SLinus Torvalds kunmap(page); 9311da177e4SLinus Torvalds unlock_page(page); 932f1adc05eSJeff Dike return err; 9331da177e4SLinus Torvalds } 9341da177e4SLinus Torvalds 935f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops = { 9361da177e4SLinus Torvalds .readpage = hostfs_link_readpage, 9371da177e4SLinus Torvalds }; 9381da177e4SLinus Torvalds 9391da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9401da177e4SLinus Torvalds { 9411da177e4SLinus Torvalds struct inode *root_inode; 94275e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9431da177e4SLinus Torvalds int err; 9441da177e4SLinus Torvalds 9451da177e4SLinus Torvalds sb->s_blocksize = 1024; 9461da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9471da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9481da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 9491da177e4SLinus Torvalds 950a6eb0be6SPaolo 'Blaisorblade' Giarrusso /* NULL is printed as <NULL> by sprintf: avoid that. */ 95175e8defbSPaolo 'Blaisorblade' Giarrusso if (req_root == NULL) 95275e8defbSPaolo 'Blaisorblade' Giarrusso req_root = ""; 9531da177e4SLinus Torvalds 9541da177e4SLinus Torvalds err = -ENOMEM; 95575e8defbSPaolo 'Blaisorblade' Giarrusso host_root_path = kmalloc(strlen(root_ino) + 1 95675e8defbSPaolo 'Blaisorblade' Giarrusso + strlen(req_root) + 1, GFP_KERNEL); 95775e8defbSPaolo 'Blaisorblade' Giarrusso if(host_root_path == NULL) 9581da177e4SLinus Torvalds goto out; 9591da177e4SLinus Torvalds 96075e8defbSPaolo 'Blaisorblade' Giarrusso sprintf(host_root_path, "%s/%s", root_ino, req_root); 9611da177e4SLinus Torvalds 9621da177e4SLinus Torvalds root_inode = iget(sb, 0); 9631da177e4SLinus Torvalds if(root_inode == NULL) 9641da177e4SLinus Torvalds goto out_free; 9651da177e4SLinus Torvalds 9661da177e4SLinus Torvalds err = init_inode(root_inode, NULL); 9671da177e4SLinus Torvalds if(err) 9681da177e4SLinus Torvalds goto out_put; 9691da177e4SLinus Torvalds 97075e8defbSPaolo 'Blaisorblade' Giarrusso HOSTFS_I(root_inode)->host_filename = host_root_path; 97175e8defbSPaolo 'Blaisorblade' Giarrusso /* Avoid that in the error path, iput(root_inode) frees again 97275e8defbSPaolo 'Blaisorblade' Giarrusso * host_root_path through hostfs_destroy_inode! */ 97375e8defbSPaolo 'Blaisorblade' Giarrusso host_root_path = NULL; 9741da177e4SLinus Torvalds 9751da177e4SLinus Torvalds err = -ENOMEM; 9761da177e4SLinus Torvalds sb->s_root = d_alloc_root(root_inode); 9771da177e4SLinus Torvalds if(sb->s_root == NULL) 9781da177e4SLinus Torvalds goto out_put; 9791da177e4SLinus Torvalds 9801da177e4SLinus Torvalds err = read_inode(root_inode); 98151a14110SJeff Dike if(err){ 98251a14110SJeff Dike /* No iput in this case because the dput does that for us */ 98351a14110SJeff Dike dput(sb->s_root); 98451a14110SJeff Dike sb->s_root = NULL; 985bca27113SPaolo 'Blaisorblade' Giarrusso goto out; 98651a14110SJeff Dike } 9871da177e4SLinus Torvalds 988f1adc05eSJeff Dike return 0; 9891da177e4SLinus Torvalds 9901da177e4SLinus Torvalds out_put: 9911da177e4SLinus Torvalds iput(root_inode); 9921da177e4SLinus Torvalds out_free: 99375e8defbSPaolo 'Blaisorblade' Giarrusso kfree(host_root_path); 9941da177e4SLinus Torvalds out: 995f1adc05eSJeff Dike return err; 9961da177e4SLinus Torvalds } 9971da177e4SLinus Torvalds 998454e2398SDavid Howells static int hostfs_read_sb(struct file_system_type *type, 9991da177e4SLinus Torvalds int flags, const char *dev_name, 1000454e2398SDavid Howells void *data, struct vfsmount *mnt) 10011da177e4SLinus Torvalds { 1002454e2398SDavid Howells return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); 10031da177e4SLinus Torvalds } 10041da177e4SLinus Torvalds 10051da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 10061da177e4SLinus Torvalds .owner = THIS_MODULE, 10071da177e4SLinus Torvalds .name = "hostfs", 10081da177e4SLinus Torvalds .get_sb = hostfs_read_sb, 10091da177e4SLinus Torvalds .kill_sb = kill_anon_super, 10101da177e4SLinus Torvalds .fs_flags = 0, 10111da177e4SLinus Torvalds }; 10121da177e4SLinus Torvalds 10131da177e4SLinus Torvalds static int __init init_hostfs(void) 10141da177e4SLinus Torvalds { 1015f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 10161da177e4SLinus Torvalds } 10171da177e4SLinus Torvalds 10181da177e4SLinus Torvalds static void __exit exit_hostfs(void) 10191da177e4SLinus Torvalds { 10201da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 10211da177e4SLinus Torvalds } 10221da177e4SLinus Torvalds 10231da177e4SLinus Torvalds module_init(init_hostfs) 10241da177e4SLinus Torvalds module_exit(exit_hostfs) 10251da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1026