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/fs.h> 101da177e4SLinus Torvalds #include <linux/module.h> 1184b3db04SJeff Dike #include <linux/mm.h> 121da177e4SLinus Torvalds #include <linux/pagemap.h> 131da177e4SLinus Torvalds #include <linux/statfs.h> 141da177e4SLinus Torvalds #include "hostfs.h" 151da177e4SLinus Torvalds #include "init.h" 1684b3db04SJeff Dike #include "kern.h" 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds struct hostfs_inode_info { 191da177e4SLinus Torvalds char *host_filename; 201da177e4SLinus Torvalds int fd; 211da177e4SLinus Torvalds int mode; 221da177e4SLinus Torvalds struct inode vfs_inode; 231da177e4SLinus Torvalds }; 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 261da177e4SLinus Torvalds { 27f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode); 281da177e4SLinus Torvalds } 291da177e4SLinus Torvalds 30680b0da9SJosef Sipek #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds int hostfs_d_delete(struct dentry *dentry) 331da177e4SLinus Torvalds { 34f1adc05eSJeff Dike return 1; 351da177e4SLinus Torvalds } 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds struct dentry_operations hostfs_dentry_ops = { 381da177e4SLinus Torvalds .d_delete = hostfs_d_delete, 391da177e4SLinus Torvalds }; 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 42a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 431da177e4SLinus Torvalds static int append = 0; 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds #define HOSTFS_SUPER_MAGIC 0x00c0ffee 461da177e4SLinus Torvalds 4792e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 4892e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 49f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds #ifndef MODULE 521da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 531da177e4SLinus Torvalds { 541da177e4SLinus Torvalds char *ptr; 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds ptr = strchr(options, ','); 571da177e4SLinus Torvalds if (ptr != NULL) 581da177e4SLinus Torvalds *ptr++ = '\0'; 591da177e4SLinus Torvalds if (*options != '\0') 601da177e4SLinus Torvalds root_ino = options; 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds options = ptr; 631da177e4SLinus Torvalds while (options) { 641da177e4SLinus Torvalds ptr = strchr(options, ','); 651da177e4SLinus Torvalds if (ptr != NULL) 661da177e4SLinus Torvalds *ptr++ = '\0'; 671da177e4SLinus Torvalds if (*options != '\0') { 681da177e4SLinus Torvalds if (!strcmp(options, "append")) 691da177e4SLinus Torvalds append = 1; 701da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 711da177e4SLinus Torvalds options); 721da177e4SLinus Torvalds } 731da177e4SLinus Torvalds options = ptr; 741da177e4SLinus Torvalds } 75f1adc05eSJeff Dike return 0; 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 791da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 801da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 811da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 821da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 831da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 841da177e4SLinus Torvalds " it.\n" 851da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 861da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 871da177e4SLinus Torvalds ); 881da177e4SLinus Torvalds #endif 891da177e4SLinus Torvalds 901da177e4SLinus Torvalds static char *dentry_name(struct dentry *dentry, int extra) 911da177e4SLinus Torvalds { 921da177e4SLinus Torvalds struct dentry *parent; 931da177e4SLinus Torvalds char *root, *name; 941da177e4SLinus Torvalds int len; 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds len = 0; 971da177e4SLinus Torvalds parent = dentry; 981da177e4SLinus Torvalds while (parent->d_parent != parent) { 991da177e4SLinus Torvalds len += parent->d_name.len + 1; 1001da177e4SLinus Torvalds parent = parent->d_parent; 1011da177e4SLinus Torvalds } 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds root = HOSTFS_I(parent->d_inode)->host_filename; 1041da177e4SLinus Torvalds len += strlen(root); 1051da177e4SLinus Torvalds name = kmalloc(len + extra + 1, GFP_KERNEL); 106f1adc05eSJeff Dike if (name == NULL) 107f1adc05eSJeff Dike return NULL; 1081da177e4SLinus Torvalds 1091da177e4SLinus Torvalds name[len] = '\0'; 1101da177e4SLinus Torvalds parent = dentry; 1111da177e4SLinus Torvalds while (parent->d_parent != parent) { 1121da177e4SLinus Torvalds len -= parent->d_name.len + 1; 1131da177e4SLinus Torvalds name[len] = '/'; 1141da177e4SLinus Torvalds strncpy(&name[len + 1], parent->d_name.name, 1151da177e4SLinus Torvalds parent->d_name.len); 1161da177e4SLinus Torvalds parent = parent->d_parent; 1171da177e4SLinus Torvalds } 1181da177e4SLinus Torvalds strncpy(name, root, strlen(root)); 119f1adc05eSJeff Dike return name; 1201da177e4SLinus Torvalds } 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds static char *inode_name(struct inode *ino, int extra) 1231da177e4SLinus Torvalds { 1241da177e4SLinus Torvalds struct dentry *dentry; 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); 127f1adc05eSJeff Dike return dentry_name(dentry, extra); 1281da177e4SLinus Torvalds } 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds static int read_name(struct inode *ino, char *name) 1311da177e4SLinus Torvalds { 13284b3db04SJeff Dike /* 13384b3db04SJeff Dike * The non-int inode fields are copied into ints by stat_file and 1341da177e4SLinus Torvalds * then copied into the inode because passing the actual pointers 1351da177e4SLinus Torvalds * in and having them treated as int * breaks on big-endian machines 1361da177e4SLinus Torvalds */ 1371da177e4SLinus Torvalds int err; 1381da177e4SLinus Torvalds int i_mode, i_nlink, i_blksize; 1391da177e4SLinus Torvalds unsigned long long i_size; 1401da177e4SLinus Torvalds unsigned long long i_ino; 1411da177e4SLinus Torvalds unsigned long long i_blocks; 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, 1441da177e4SLinus Torvalds &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, 1455822b7faSAlberto Bertogli &ino->i_ctime, &i_blksize, &i_blocks, -1); 1461da177e4SLinus Torvalds if (err) 147f1adc05eSJeff Dike return err; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds ino->i_ino = i_ino; 1501da177e4SLinus Torvalds ino->i_mode = i_mode; 1511da177e4SLinus Torvalds ino->i_nlink = i_nlink; 1521da177e4SLinus Torvalds ino->i_size = i_size; 1531da177e4SLinus Torvalds ino->i_blocks = i_blocks; 154f1adc05eSJeff Dike return 0; 1551da177e4SLinus Torvalds } 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds static char *follow_link(char *link) 1581da177e4SLinus Torvalds { 1591da177e4SLinus Torvalds int len, n; 1601da177e4SLinus Torvalds char *name, *resolved, *end; 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds len = 64; 1631da177e4SLinus Torvalds while (1) { 1641da177e4SLinus Torvalds n = -ENOMEM; 1651da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1661da177e4SLinus Torvalds if (name == NULL) 1671da177e4SLinus Torvalds goto out; 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvalds n = do_readlink(link, name, len); 1701da177e4SLinus Torvalds if (n < len) 1711da177e4SLinus Torvalds break; 1721da177e4SLinus Torvalds len *= 2; 1731da177e4SLinus Torvalds kfree(name); 1741da177e4SLinus Torvalds } 1751da177e4SLinus Torvalds if (n < 0) 1761da177e4SLinus Torvalds goto out_free; 1771da177e4SLinus Torvalds 1781da177e4SLinus Torvalds if (*name == '/') 179f1adc05eSJeff Dike return name; 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds end = strrchr(link, '/'); 1821da177e4SLinus Torvalds if (end == NULL) 183f1adc05eSJeff Dike return name; 1841da177e4SLinus Torvalds 1851da177e4SLinus Torvalds *(end + 1) = '\0'; 1861da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1871da177e4SLinus Torvalds 1881da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 1891da177e4SLinus Torvalds if (resolved == NULL) { 1901da177e4SLinus Torvalds n = -ENOMEM; 1911da177e4SLinus Torvalds goto out_free; 1921da177e4SLinus Torvalds } 1931da177e4SLinus Torvalds 1941da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 1951da177e4SLinus Torvalds kfree(name); 1961da177e4SLinus Torvalds kfree(link); 197f1adc05eSJeff Dike return resolved; 1981da177e4SLinus Torvalds 1991da177e4SLinus Torvalds out_free: 2001da177e4SLinus Torvalds kfree(name); 2011da177e4SLinus Torvalds out: 202f1adc05eSJeff Dike return ERR_PTR(n); 2031da177e4SLinus Torvalds } 2041da177e4SLinus Torvalds 2051da177e4SLinus Torvalds static int read_inode(struct inode *ino) 2061da177e4SLinus Torvalds { 2071da177e4SLinus Torvalds char *name; 2081da177e4SLinus Torvalds int err = 0; 2091da177e4SLinus Torvalds 21084b3db04SJeff Dike /* 21184b3db04SJeff Dike * Unfortunately, we are called from iget() when we don't have a dentry 2121da177e4SLinus Torvalds * allocated yet. 2131da177e4SLinus Torvalds */ 2141da177e4SLinus Torvalds if (list_empty(&ino->i_dentry)) 2151da177e4SLinus Torvalds goto out; 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds err = -ENOMEM; 2181da177e4SLinus Torvalds name = inode_name(ino, 0); 2191da177e4SLinus Torvalds if (name == NULL) 2201da177e4SLinus Torvalds goto out; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds if (file_type(name, NULL, NULL) == OS_TYPE_SYMLINK) { 2231da177e4SLinus Torvalds name = follow_link(name); 2241da177e4SLinus Torvalds if (IS_ERR(name)) { 2251da177e4SLinus Torvalds err = PTR_ERR(name); 2261da177e4SLinus Torvalds goto out; 2271da177e4SLinus Torvalds } 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds 2301da177e4SLinus Torvalds err = read_name(ino, name); 2311da177e4SLinus Torvalds kfree(name); 2321da177e4SLinus Torvalds out: 233f1adc05eSJeff Dike return err; 2341da177e4SLinus Torvalds } 2351da177e4SLinus Torvalds 236726c3342SDavid Howells int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 2371da177e4SLinus Torvalds { 23884b3db04SJeff Dike /* 23984b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 2401da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 2411da177e4SLinus Torvalds * so we convert them here 2421da177e4SLinus Torvalds */ 2431da177e4SLinus Torvalds int err; 2441da177e4SLinus Torvalds long long f_blocks; 2451da177e4SLinus Torvalds long long f_bfree; 2461da177e4SLinus Torvalds long long f_bavail; 2471da177e4SLinus Torvalds long long f_files; 2481da177e4SLinus Torvalds long long f_ffree; 2491da177e4SLinus Torvalds 250726c3342SDavid Howells err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename, 2511da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2521da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2531da177e4SLinus Torvalds &sf->f_namelen, sf->f_spare); 254f1adc05eSJeff Dike if (err) 255f1adc05eSJeff Dike return err; 2561da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2571da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2581da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2591da177e4SLinus Torvalds sf->f_files = f_files; 2601da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2611da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 262f1adc05eSJeff Dike return 0; 2631da177e4SLinus Torvalds } 2641da177e4SLinus Torvalds 2651da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2661da177e4SLinus Torvalds { 2671da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2681da177e4SLinus Torvalds 2691da177e4SLinus Torvalds hi = kmalloc(sizeof(*hi), GFP_KERNEL); 2701da177e4SLinus Torvalds if (hi == NULL) 271f1adc05eSJeff Dike return NULL; 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds *hi = ((struct hostfs_inode_info) { .host_filename = NULL, 2741da177e4SLinus Torvalds .fd = -1, 2751da177e4SLinus Torvalds .mode = 0 }); 2761da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 277f1adc05eSJeff Dike return &hi->vfs_inode; 2781da177e4SLinus Torvalds } 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds static void hostfs_delete_inode(struct inode *inode) 2811da177e4SLinus Torvalds { 282fef26658SMark Fasheh truncate_inode_pages(&inode->i_data, 0); 2831da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2841da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2851da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2861da177e4SLinus Torvalds } 2871da177e4SLinus Torvalds clear_inode(inode); 2881da177e4SLinus Torvalds } 2891da177e4SLinus Torvalds 2901da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2911da177e4SLinus Torvalds { 2921da177e4SLinus Torvalds kfree(HOSTFS_I(inode)->host_filename); 2931da177e4SLinus Torvalds 29484b3db04SJeff Dike /* 29584b3db04SJeff Dike * XXX: This should not happen, probably. The check is here for 29684b3db04SJeff Dike * additional safety. 29784b3db04SJeff Dike */ 2981da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2991da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 3001da177e4SLinus Torvalds printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); 3011da177e4SLinus Torvalds } 3021da177e4SLinus Torvalds 3031da177e4SLinus Torvalds kfree(HOSTFS_I(inode)); 3041da177e4SLinus Torvalds } 3051da177e4SLinus Torvalds 3061da177e4SLinus Torvalds static void hostfs_read_inode(struct inode *inode) 3071da177e4SLinus Torvalds { 3081da177e4SLinus Torvalds read_inode(inode); 3091da177e4SLinus Torvalds } 3101da177e4SLinus Torvalds 311ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 3121da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 3131da177e4SLinus Torvalds .drop_inode = generic_delete_inode, 3141da177e4SLinus Torvalds .delete_inode = hostfs_delete_inode, 3151da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 3161da177e4SLinus Torvalds .read_inode = hostfs_read_inode, 3171da177e4SLinus Torvalds .statfs = hostfs_statfs, 3181da177e4SLinus Torvalds }; 3191da177e4SLinus Torvalds 3201da177e4SLinus Torvalds int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) 3211da177e4SLinus Torvalds { 3221da177e4SLinus Torvalds void *dir; 3231da177e4SLinus Torvalds char *name; 3241da177e4SLinus Torvalds unsigned long long next, ino; 3251da177e4SLinus Torvalds int error, len; 3261da177e4SLinus Torvalds 327680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 328f1adc05eSJeff Dike if (name == NULL) 329f1adc05eSJeff Dike return -ENOMEM; 3301da177e4SLinus Torvalds dir = open_dir(name, &error); 3311da177e4SLinus Torvalds kfree(name); 332f1adc05eSJeff Dike if (dir == NULL) 333f1adc05eSJeff Dike return -error; 3341da177e4SLinus Torvalds next = file->f_pos; 3351da177e4SLinus Torvalds while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { 3361da177e4SLinus Torvalds error = (*filldir)(ent, name, len, file->f_pos, 3371da177e4SLinus Torvalds ino, DT_UNKNOWN); 3381da177e4SLinus Torvalds if (error) break; 3391da177e4SLinus Torvalds file->f_pos = next; 3401da177e4SLinus Torvalds } 3411da177e4SLinus Torvalds close_dir(dir); 342f1adc05eSJeff Dike return 0; 3431da177e4SLinus Torvalds } 3441da177e4SLinus Torvalds 3451da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 3461da177e4SLinus Torvalds { 3471da177e4SLinus Torvalds char *name; 3481da177e4SLinus Torvalds int mode = 0, r = 0, w = 0, fd; 3491da177e4SLinus Torvalds 3501da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3511da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode) 352f1adc05eSJeff Dike return 0; 3531da177e4SLinus Torvalds 35484b3db04SJeff Dike /* 35584b3db04SJeff Dike * The file may already have been opened, but with the wrong access, 3561da177e4SLinus Torvalds * so this resets things and reopens the file with the new access. 3571da177e4SLinus Torvalds */ 3581da177e4SLinus Torvalds if (HOSTFS_I(ino)->fd != -1) { 3591da177e4SLinus Torvalds close_file(&HOSTFS_I(ino)->fd); 3601da177e4SLinus Torvalds HOSTFS_I(ino)->fd = -1; 3611da177e4SLinus Torvalds } 3621da177e4SLinus Torvalds 3631da177e4SLinus Torvalds HOSTFS_I(ino)->mode |= mode; 3641da177e4SLinus Torvalds if (HOSTFS_I(ino)->mode & FMODE_READ) 3651da177e4SLinus Torvalds r = 1; 3661da177e4SLinus Torvalds if (HOSTFS_I(ino)->mode & FMODE_WRITE) 3671da177e4SLinus Torvalds w = 1; 3681da177e4SLinus Torvalds if (w) 3691da177e4SLinus Torvalds r = 1; 3701da177e4SLinus Torvalds 371680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 3721da177e4SLinus Torvalds if (name == NULL) 373f1adc05eSJeff Dike return -ENOMEM; 3741da177e4SLinus Torvalds 3751da177e4SLinus Torvalds fd = open_file(name, r, w, append); 3761da177e4SLinus Torvalds kfree(name); 377f1adc05eSJeff Dike if (fd < 0) 378f1adc05eSJeff Dike return fd; 3791da177e4SLinus Torvalds FILE_HOSTFS_I(file)->fd = fd; 3801da177e4SLinus Torvalds 381f1adc05eSJeff Dike return 0; 3821da177e4SLinus Torvalds } 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvalds int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) 3851da177e4SLinus Torvalds { 386a2d76bd8SPaolo 'Blaisorblade' Giarrusso return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); 3871da177e4SLinus Torvalds } 3881da177e4SLinus Torvalds 3894b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3901da177e4SLinus Torvalds .llseek = generic_file_llseek, 391543ade1fSBadari Pulavarty .read = do_sync_read, 3925ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3931da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3941da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 395543ade1fSBadari Pulavarty .write = do_sync_write, 3961da177e4SLinus Torvalds .mmap = generic_file_mmap, 3971da177e4SLinus Torvalds .open = hostfs_file_open, 3981da177e4SLinus Torvalds .release = NULL, 3991da177e4SLinus Torvalds .fsync = hostfs_fsync, 4001da177e4SLinus Torvalds }; 4011da177e4SLinus Torvalds 4024b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 4031da177e4SLinus Torvalds .llseek = generic_file_llseek, 4041da177e4SLinus Torvalds .readdir = hostfs_readdir, 4051da177e4SLinus Torvalds .read = generic_read_dir, 4061da177e4SLinus Torvalds }; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4091da177e4SLinus Torvalds { 4101da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4111da177e4SLinus Torvalds struct inode *inode = mapping->host; 4121da177e4SLinus Torvalds char *buffer; 4131da177e4SLinus Torvalds unsigned long long base; 4141da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 4151da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 4161da177e4SLinus Torvalds int err; 4171da177e4SLinus Torvalds 4181da177e4SLinus Torvalds if (page->index >= end_index) 4191da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds buffer = kmap(page); 4221da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 4231da177e4SLinus Torvalds 4241da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4251da177e4SLinus Torvalds if (err != count) { 4261da177e4SLinus Torvalds ClearPageUptodate(page); 4271da177e4SLinus Torvalds goto out; 4281da177e4SLinus Torvalds } 4291da177e4SLinus Torvalds 4301da177e4SLinus Torvalds if (base > inode->i_size) 4311da177e4SLinus Torvalds inode->i_size = base; 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds if (PageError(page)) 4341da177e4SLinus Torvalds ClearPageError(page); 4351da177e4SLinus Torvalds err = 0; 4361da177e4SLinus Torvalds 4371da177e4SLinus Torvalds out: 4381da177e4SLinus Torvalds kunmap(page); 4391da177e4SLinus Torvalds 4401da177e4SLinus Torvalds unlock_page(page); 4411da177e4SLinus Torvalds return err; 4421da177e4SLinus Torvalds } 4431da177e4SLinus Torvalds 4441da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4451da177e4SLinus Torvalds { 4461da177e4SLinus Torvalds char *buffer; 4471da177e4SLinus Torvalds long long start; 4481da177e4SLinus Torvalds int err = 0; 4491da177e4SLinus Torvalds 4501da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4511da177e4SLinus Torvalds buffer = kmap(page); 4521da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4531da177e4SLinus Torvalds PAGE_CACHE_SIZE); 45484b3db04SJeff Dike if (err < 0) 45584b3db04SJeff Dike 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 49784b3db04SJeff Dike /* 49884b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 499ae361ff4SNick Piggin * i_size against the last byte written. 500ae361ff4SNick Piggin */ 501ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 502ae361ff4SNick Piggin inode->i_size = pos; 503ae361ff4SNick Piggin unlock_page(page); 504ae361ff4SNick Piggin page_cache_release(page); 50530f04a4eSPaolo 'Blaisorblade' Giarrusso 506f1adc05eSJeff Dike return err; 5071da177e4SLinus Torvalds } 5081da177e4SLinus Torvalds 509f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 5101da177e4SLinus Torvalds .writepage = hostfs_writepage, 5111da177e4SLinus Torvalds .readpage = hostfs_readpage, 512ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 513ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 514ae361ff4SNick Piggin .write_end = hostfs_write_end, 5151da177e4SLinus Torvalds }; 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds static int init_inode(struct inode *inode, struct dentry *dentry) 5181da177e4SLinus Torvalds { 5191da177e4SLinus Torvalds char *name; 5201da177e4SLinus Torvalds int type, err = -ENOMEM; 5211da177e4SLinus Torvalds int maj, min; 5221da177e4SLinus Torvalds dev_t rdev = 0; 5231da177e4SLinus Torvalds 5241da177e4SLinus Torvalds if (dentry) { 5251da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5261da177e4SLinus Torvalds if (name == NULL) 5271da177e4SLinus Torvalds goto out; 5281da177e4SLinus Torvalds type = file_type(name, &maj, &min); 5291da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5301da177e4SLinus Torvalds rdev = MKDEV(maj, min); 5311da177e4SLinus Torvalds kfree(name); 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds else type = OS_TYPE_DIR; 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds err = 0; 5361da177e4SLinus Torvalds if (type == OS_TYPE_SYMLINK) 5371da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations; 5381da177e4SLinus Torvalds else if (type == OS_TYPE_DIR) 5391da177e4SLinus Torvalds inode->i_op = &hostfs_dir_iops; 5401da177e4SLinus Torvalds else inode->i_op = &hostfs_iops; 5411da177e4SLinus Torvalds 5421da177e4SLinus Torvalds if (type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; 5431da177e4SLinus Torvalds else inode->i_fop = &hostfs_file_fops; 5441da177e4SLinus Torvalds 5451da177e4SLinus Torvalds if (type == OS_TYPE_SYMLINK) 5461da177e4SLinus Torvalds inode->i_mapping->a_ops = &hostfs_link_aops; 5471da177e4SLinus Torvalds else inode->i_mapping->a_ops = &hostfs_aops; 5481da177e4SLinus Torvalds 5491da177e4SLinus Torvalds switch (type) { 5501da177e4SLinus Torvalds case OS_TYPE_CHARDEV: 5511da177e4SLinus Torvalds init_special_inode(inode, S_IFCHR, rdev); 5521da177e4SLinus Torvalds break; 5531da177e4SLinus Torvalds case OS_TYPE_BLOCKDEV: 5541da177e4SLinus Torvalds init_special_inode(inode, S_IFBLK, rdev); 5551da177e4SLinus Torvalds break; 5561da177e4SLinus Torvalds case OS_TYPE_FIFO: 5571da177e4SLinus Torvalds init_special_inode(inode, S_IFIFO, 0); 5581da177e4SLinus Torvalds break; 5591da177e4SLinus Torvalds case OS_TYPE_SOCK: 5601da177e4SLinus Torvalds init_special_inode(inode, S_IFSOCK, 0); 5611da177e4SLinus Torvalds break; 5621da177e4SLinus Torvalds } 5631da177e4SLinus Torvalds out: 564f1adc05eSJeff Dike return err; 5651da177e4SLinus Torvalds } 5661da177e4SLinus Torvalds 5671da177e4SLinus Torvalds int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, 5681da177e4SLinus Torvalds struct nameidata *nd) 5691da177e4SLinus Torvalds { 5701da177e4SLinus Torvalds struct inode *inode; 5711da177e4SLinus Torvalds char *name; 5721da177e4SLinus Torvalds int error, fd; 5731da177e4SLinus Torvalds 5741da177e4SLinus Torvalds error = -ENOMEM; 5751da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 57684b3db04SJeff Dike if (inode == NULL) 57784b3db04SJeff Dike goto out; 5781da177e4SLinus Torvalds 5791da177e4SLinus Torvalds error = init_inode(inode, dentry); 5801da177e4SLinus Torvalds if (error) 5811da177e4SLinus Torvalds goto out_put; 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds error = -ENOMEM; 5841da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5851da177e4SLinus Torvalds if (name == NULL) 5861da177e4SLinus Torvalds goto out_put; 5871da177e4SLinus Torvalds 5881da177e4SLinus Torvalds fd = file_create(name, 5891da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 5901da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 5911da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 5921da177e4SLinus Torvalds if (fd < 0) 5931da177e4SLinus Torvalds error = fd; 5941da177e4SLinus Torvalds else error = read_name(inode, name); 5951da177e4SLinus Torvalds 5961da177e4SLinus Torvalds kfree(name); 5971da177e4SLinus Torvalds if (error) 5981da177e4SLinus Torvalds goto out_put; 5991da177e4SLinus Torvalds 6001da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 6011da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 6021da177e4SLinus Torvalds d_instantiate(dentry, inode); 603f1adc05eSJeff Dike return 0; 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds out_put: 6061da177e4SLinus Torvalds iput(inode); 6071da177e4SLinus Torvalds out: 608f1adc05eSJeff Dike return error; 6091da177e4SLinus Torvalds } 6101da177e4SLinus Torvalds 6111da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 6121da177e4SLinus Torvalds struct nameidata *nd) 6131da177e4SLinus Torvalds { 6141da177e4SLinus Torvalds struct inode *inode; 6151da177e4SLinus Torvalds char *name; 6161da177e4SLinus Torvalds int err; 6171da177e4SLinus Torvalds 6181da177e4SLinus Torvalds err = -ENOMEM; 6191da177e4SLinus Torvalds inode = iget(ino->i_sb, 0); 6201da177e4SLinus Torvalds if (inode == NULL) 6211da177e4SLinus Torvalds goto out; 6221da177e4SLinus Torvalds 6231da177e4SLinus Torvalds err = init_inode(inode, dentry); 6241da177e4SLinus Torvalds if (err) 6251da177e4SLinus Torvalds goto out_put; 6261da177e4SLinus Torvalds 6271da177e4SLinus Torvalds err = -ENOMEM; 6281da177e4SLinus Torvalds name = dentry_name(dentry, 0); 6291da177e4SLinus Torvalds if (name == NULL) 6301da177e4SLinus Torvalds goto out_put; 6311da177e4SLinus Torvalds 6321da177e4SLinus Torvalds err = read_name(inode, name); 6331da177e4SLinus Torvalds kfree(name); 6341da177e4SLinus Torvalds if (err == -ENOENT) { 6351da177e4SLinus Torvalds iput(inode); 6361da177e4SLinus Torvalds inode = NULL; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds else if (err) 6391da177e4SLinus Torvalds goto out_put; 6401da177e4SLinus Torvalds 6411da177e4SLinus Torvalds d_add(dentry, inode); 6421da177e4SLinus Torvalds dentry->d_op = &hostfs_dentry_ops; 643f1adc05eSJeff Dike return NULL; 6441da177e4SLinus Torvalds 6451da177e4SLinus Torvalds out_put: 6461da177e4SLinus Torvalds iput(inode); 6471da177e4SLinus Torvalds out: 648f1adc05eSJeff Dike return ERR_PTR(err); 6491da177e4SLinus Torvalds } 6501da177e4SLinus Torvalds 6511da177e4SLinus Torvalds static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) 6521da177e4SLinus Torvalds { 6531da177e4SLinus Torvalds char *file; 6541da177e4SLinus Torvalds int len; 6551da177e4SLinus Torvalds 6561da177e4SLinus Torvalds file = inode_name(ino, dentry->d_name.len + 1); 657f1adc05eSJeff Dike if (file == NULL) 658f1adc05eSJeff Dike return NULL; 6591da177e4SLinus Torvalds strcat(file, "/"); 6601da177e4SLinus Torvalds len = strlen(file); 6611da177e4SLinus Torvalds strncat(file, dentry->d_name.name, dentry->d_name.len); 6621da177e4SLinus Torvalds file[len + dentry->d_name.len] = '\0'; 663f1adc05eSJeff Dike return file; 6641da177e4SLinus Torvalds } 6651da177e4SLinus Torvalds 6661da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6671da177e4SLinus Torvalds { 6681da177e4SLinus Torvalds char *from_name, *to_name; 6691da177e4SLinus Torvalds int err; 6701da177e4SLinus Torvalds 6711da177e4SLinus Torvalds if ((from_name = inode_dentry_name(ino, from)) == NULL) 672f1adc05eSJeff Dike return -ENOMEM; 6731da177e4SLinus Torvalds to_name = dentry_name(to, 0); 6741da177e4SLinus Torvalds if (to_name == NULL) { 6751da177e4SLinus Torvalds kfree(from_name); 676f1adc05eSJeff Dike return -ENOMEM; 6771da177e4SLinus Torvalds } 6781da177e4SLinus Torvalds err = link_file(to_name, from_name); 6791da177e4SLinus Torvalds kfree(from_name); 6801da177e4SLinus Torvalds kfree(to_name); 681f1adc05eSJeff Dike return err; 6821da177e4SLinus Torvalds } 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6851da177e4SLinus Torvalds { 6861da177e4SLinus Torvalds char *file; 6871da177e4SLinus Torvalds int err; 6881da177e4SLinus Torvalds 689f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 690f1adc05eSJeff Dike return -ENOMEM; 6911da177e4SLinus Torvalds if (append) 692f1adc05eSJeff Dike return -EPERM; 6931da177e4SLinus Torvalds 6941da177e4SLinus Torvalds err = unlink_file(file); 6951da177e4SLinus Torvalds kfree(file); 696f1adc05eSJeff Dike return err; 6971da177e4SLinus Torvalds } 6981da177e4SLinus Torvalds 6991da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 7001da177e4SLinus Torvalds { 7011da177e4SLinus Torvalds char *file; 7021da177e4SLinus Torvalds int err; 7031da177e4SLinus Torvalds 704f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 705f1adc05eSJeff Dike return -ENOMEM; 7061da177e4SLinus Torvalds err = make_symlink(file, to); 7071da177e4SLinus Torvalds kfree(file); 708f1adc05eSJeff Dike return err; 7091da177e4SLinus Torvalds } 7101da177e4SLinus Torvalds 7111da177e4SLinus Torvalds int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) 7121da177e4SLinus Torvalds { 7131da177e4SLinus Torvalds char *file; 7141da177e4SLinus Torvalds int err; 7151da177e4SLinus Torvalds 716f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 717f1adc05eSJeff Dike return -ENOMEM; 7181da177e4SLinus Torvalds err = do_mkdir(file, mode); 7191da177e4SLinus Torvalds kfree(file); 720f1adc05eSJeff Dike return err; 7211da177e4SLinus Torvalds } 7221da177e4SLinus Torvalds 7231da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 7241da177e4SLinus Torvalds { 7251da177e4SLinus Torvalds char *file; 7261da177e4SLinus Torvalds int err; 7271da177e4SLinus Torvalds 728f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 729f1adc05eSJeff Dike return -ENOMEM; 7301da177e4SLinus Torvalds err = do_rmdir(file); 7311da177e4SLinus Torvalds kfree(file); 732f1adc05eSJeff Dike return err; 7331da177e4SLinus Torvalds } 7341da177e4SLinus Torvalds 7351da177e4SLinus Torvalds int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 7361da177e4SLinus Torvalds { 7371da177e4SLinus Torvalds struct inode *inode; 7381da177e4SLinus Torvalds char *name; 7391da177e4SLinus Torvalds int err = -ENOMEM; 7401da177e4SLinus Torvalds 7411da177e4SLinus Torvalds inode = iget(dir->i_sb, 0); 7421da177e4SLinus Torvalds if (inode == NULL) 7431da177e4SLinus Torvalds goto out; 7441da177e4SLinus Torvalds 7451da177e4SLinus Torvalds err = init_inode(inode, dentry); 7461da177e4SLinus Torvalds if (err) 7471da177e4SLinus Torvalds goto out_put; 7481da177e4SLinus Torvalds 7491da177e4SLinus Torvalds err = -ENOMEM; 7501da177e4SLinus Torvalds name = dentry_name(dentry, 0); 7511da177e4SLinus Torvalds if (name == NULL) 7521da177e4SLinus Torvalds goto out_put; 7531da177e4SLinus Torvalds 7541da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 75588f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 7561da177e4SLinus Torvalds if (err) 7571da177e4SLinus Torvalds goto out_free; 7581da177e4SLinus Torvalds 7591da177e4SLinus Torvalds err = read_name(inode, name); 7601da177e4SLinus Torvalds kfree(name); 7611da177e4SLinus Torvalds if (err) 7621da177e4SLinus Torvalds goto out_put; 7631da177e4SLinus Torvalds 7641da177e4SLinus Torvalds d_instantiate(dentry, inode); 765f1adc05eSJeff Dike return 0; 7661da177e4SLinus Torvalds 7671da177e4SLinus Torvalds out_free: 7681da177e4SLinus Torvalds kfree(name); 7691da177e4SLinus Torvalds out_put: 7701da177e4SLinus Torvalds iput(inode); 7711da177e4SLinus Torvalds out: 772f1adc05eSJeff Dike return err; 7731da177e4SLinus Torvalds } 7741da177e4SLinus Torvalds 7751da177e4SLinus Torvalds int hostfs_rename(struct inode *from_ino, struct dentry *from, 7761da177e4SLinus Torvalds struct inode *to_ino, struct dentry *to) 7771da177e4SLinus Torvalds { 7781da177e4SLinus Torvalds char *from_name, *to_name; 7791da177e4SLinus Torvalds int err; 7801da177e4SLinus Torvalds 7811da177e4SLinus Torvalds if ((from_name = inode_dentry_name(from_ino, from)) == NULL) 782f1adc05eSJeff Dike return -ENOMEM; 7831da177e4SLinus Torvalds if ((to_name = inode_dentry_name(to_ino, to)) == NULL) { 7841da177e4SLinus Torvalds kfree(from_name); 785f1adc05eSJeff Dike return -ENOMEM; 7861da177e4SLinus Torvalds } 7871da177e4SLinus Torvalds err = rename_file(from_name, to_name); 7881da177e4SLinus Torvalds kfree(from_name); 7891da177e4SLinus Torvalds kfree(to_name); 790f1adc05eSJeff Dike return err; 7911da177e4SLinus Torvalds } 7921da177e4SLinus Torvalds 7931da177e4SLinus Torvalds int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) 7941da177e4SLinus Torvalds { 7951da177e4SLinus Torvalds char *name; 7961da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7971da177e4SLinus Torvalds 7981da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7991da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 8001da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 8011da177e4SLinus Torvalds name = inode_name(ino, 0); 802f1adc05eSJeff Dike if (name == NULL) 803f1adc05eSJeff Dike return -ENOMEM; 8041da177e4SLinus Torvalds 8051da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 8061da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 8071da177e4SLinus Torvalds err = 0; 8081da177e4SLinus Torvalds else 8091da177e4SLinus Torvalds err = access_file(name, r, w, x); 8101da177e4SLinus Torvalds kfree(name); 8111da177e4SLinus Torvalds if (!err) 8121da177e4SLinus Torvalds err = generic_permission(ino, desired, NULL); 8131da177e4SLinus Torvalds return err; 8141da177e4SLinus Torvalds } 8151da177e4SLinus Torvalds 8161da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 8171da177e4SLinus Torvalds { 8181da177e4SLinus Torvalds struct hostfs_iattr attrs; 8191da177e4SLinus Torvalds char *name; 8201da177e4SLinus Torvalds int err; 8211da177e4SLinus Torvalds 8225822b7faSAlberto Bertogli int fd = HOSTFS_I(dentry->d_inode)->fd; 8235822b7faSAlberto Bertogli 8241da177e4SLinus Torvalds err = inode_change_ok(dentry->d_inode, attr); 8251da177e4SLinus Torvalds if (err) 8261da177e4SLinus Torvalds return err; 8271da177e4SLinus Torvalds 8281da177e4SLinus Torvalds if (append) 8291da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8301da177e4SLinus Torvalds 8311da177e4SLinus Torvalds attrs.ia_valid = 0; 8321da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) { 8331da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8341da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8351da177e4SLinus Torvalds } 8361da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) { 8371da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 8381da177e4SLinus Torvalds attrs.ia_uid = attr->ia_uid; 8391da177e4SLinus Torvalds } 8401da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8411da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 8421da177e4SLinus Torvalds attrs.ia_gid = attr->ia_gid; 8431da177e4SLinus Torvalds } 8441da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) { 8451da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8461da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8471da177e4SLinus Torvalds } 8481da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) { 8491da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8501da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8511da177e4SLinus Torvalds } 8521da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8531da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8541da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8551da177e4SLinus Torvalds } 8561da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8571da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8581da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 8591da177e4SLinus Torvalds } 8601da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) { 8611da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8621da177e4SLinus Torvalds } 8631da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) { 8641da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8651da177e4SLinus Torvalds } 8661da177e4SLinus Torvalds name = dentry_name(dentry, 0); 867f1adc05eSJeff Dike if (name == NULL) 868f1adc05eSJeff Dike return -ENOMEM; 8695822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 8701da177e4SLinus Torvalds kfree(name); 8711da177e4SLinus Torvalds if (err) 872f1adc05eSJeff Dike return err; 8731da177e4SLinus Torvalds 874f1adc05eSJeff Dike return inode_setattr(dentry->d_inode, attr); 8751da177e4SLinus Torvalds } 8761da177e4SLinus Torvalds 87792e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8781da177e4SLinus Torvalds .create = hostfs_create, 8791da177e4SLinus Torvalds .link = hostfs_link, 8801da177e4SLinus Torvalds .unlink = hostfs_unlink, 8811da177e4SLinus Torvalds .symlink = hostfs_symlink, 8821da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8831da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8841da177e4SLinus Torvalds .mknod = hostfs_mknod, 8851da177e4SLinus Torvalds .rename = hostfs_rename, 8861da177e4SLinus Torvalds .permission = hostfs_permission, 8871da177e4SLinus Torvalds .setattr = hostfs_setattr, 8881da177e4SLinus Torvalds }; 8891da177e4SLinus Torvalds 89092e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8911da177e4SLinus Torvalds .create = hostfs_create, 8921da177e4SLinus Torvalds .lookup = hostfs_lookup, 8931da177e4SLinus Torvalds .link = hostfs_link, 8941da177e4SLinus Torvalds .unlink = hostfs_unlink, 8951da177e4SLinus Torvalds .symlink = hostfs_symlink, 8961da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8971da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8981da177e4SLinus Torvalds .mknod = hostfs_mknod, 8991da177e4SLinus Torvalds .rename = hostfs_rename, 9001da177e4SLinus Torvalds .permission = hostfs_permission, 9011da177e4SLinus Torvalds .setattr = hostfs_setattr, 9021da177e4SLinus Torvalds }; 9031da177e4SLinus Torvalds 9041da177e4SLinus Torvalds int hostfs_link_readpage(struct file *file, struct page *page) 9051da177e4SLinus Torvalds { 9061da177e4SLinus Torvalds char *buffer, *name; 9071da177e4SLinus Torvalds int err; 9081da177e4SLinus Torvalds 9091da177e4SLinus Torvalds buffer = kmap(page); 9101da177e4SLinus Torvalds name = inode_name(page->mapping->host, 0); 911f1adc05eSJeff Dike if (name == NULL) 912f1adc05eSJeff Dike return -ENOMEM; 9131da177e4SLinus Torvalds err = do_readlink(name, buffer, PAGE_CACHE_SIZE); 9141da177e4SLinus Torvalds kfree(name); 9151da177e4SLinus Torvalds if (err == PAGE_CACHE_SIZE) 9161da177e4SLinus Torvalds err = -E2BIG; 9171da177e4SLinus Torvalds else if (err > 0) { 9181da177e4SLinus Torvalds flush_dcache_page(page); 9191da177e4SLinus Torvalds SetPageUptodate(page); 9201da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 9211da177e4SLinus Torvalds err = 0; 9221da177e4SLinus Torvalds } 9231da177e4SLinus Torvalds kunmap(page); 9241da177e4SLinus Torvalds unlock_page(page); 925f1adc05eSJeff Dike return err; 9261da177e4SLinus Torvalds } 9271da177e4SLinus Torvalds 928f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops = { 9291da177e4SLinus Torvalds .readpage = hostfs_link_readpage, 9301da177e4SLinus Torvalds }; 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9331da177e4SLinus Torvalds { 9341da177e4SLinus Torvalds struct inode *root_inode; 93575e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9361da177e4SLinus Torvalds int err; 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds sb->s_blocksize = 1024; 9391da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9401da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9411da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 9421da177e4SLinus Torvalds 943a6eb0be6SPaolo 'Blaisorblade' Giarrusso /* NULL is printed as <NULL> by sprintf: avoid that. */ 94475e8defbSPaolo 'Blaisorblade' Giarrusso if (req_root == NULL) 94575e8defbSPaolo 'Blaisorblade' Giarrusso req_root = ""; 9461da177e4SLinus Torvalds 9471da177e4SLinus Torvalds err = -ENOMEM; 94875e8defbSPaolo 'Blaisorblade' Giarrusso host_root_path = kmalloc(strlen(root_ino) + 1 94975e8defbSPaolo 'Blaisorblade' Giarrusso + strlen(req_root) + 1, GFP_KERNEL); 95075e8defbSPaolo 'Blaisorblade' Giarrusso if (host_root_path == NULL) 9511da177e4SLinus Torvalds goto out; 9521da177e4SLinus Torvalds 95375e8defbSPaolo 'Blaisorblade' Giarrusso sprintf(host_root_path, "%s/%s", root_ino, req_root); 9541da177e4SLinus Torvalds 9551da177e4SLinus Torvalds root_inode = iget(sb, 0); 9561da177e4SLinus Torvalds if (root_inode == NULL) 9571da177e4SLinus Torvalds goto out_free; 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvalds err = init_inode(root_inode, NULL); 9601da177e4SLinus Torvalds if (err) 9611da177e4SLinus Torvalds goto out_put; 9621da177e4SLinus Torvalds 96375e8defbSPaolo 'Blaisorblade' Giarrusso HOSTFS_I(root_inode)->host_filename = host_root_path; 96484b3db04SJeff Dike /* 96584b3db04SJeff Dike * Avoid that in the error path, iput(root_inode) frees again 96684b3db04SJeff Dike * host_root_path through hostfs_destroy_inode! 96784b3db04SJeff Dike */ 96875e8defbSPaolo 'Blaisorblade' Giarrusso host_root_path = NULL; 9691da177e4SLinus Torvalds 9701da177e4SLinus Torvalds err = -ENOMEM; 9711da177e4SLinus Torvalds sb->s_root = d_alloc_root(root_inode); 9721da177e4SLinus Torvalds if (sb->s_root == NULL) 9731da177e4SLinus Torvalds goto out_put; 9741da177e4SLinus Torvalds 9751da177e4SLinus Torvalds err = read_inode(root_inode); 97651a14110SJeff Dike if (err) { 97751a14110SJeff Dike /* No iput in this case because the dput does that for us */ 97851a14110SJeff Dike dput(sb->s_root); 97951a14110SJeff Dike sb->s_root = NULL; 980bca27113SPaolo 'Blaisorblade' Giarrusso goto out; 98151a14110SJeff Dike } 9821da177e4SLinus Torvalds 983f1adc05eSJeff Dike return 0; 9841da177e4SLinus Torvalds 9851da177e4SLinus Torvalds out_put: 9861da177e4SLinus Torvalds iput(root_inode); 9871da177e4SLinus Torvalds out_free: 98875e8defbSPaolo 'Blaisorblade' Giarrusso kfree(host_root_path); 9891da177e4SLinus Torvalds out: 990f1adc05eSJeff Dike return err; 9911da177e4SLinus Torvalds } 9921da177e4SLinus Torvalds 993454e2398SDavid Howells static int hostfs_read_sb(struct file_system_type *type, 9941da177e4SLinus Torvalds int flags, const char *dev_name, 995454e2398SDavid Howells void *data, struct vfsmount *mnt) 9961da177e4SLinus Torvalds { 997454e2398SDavid Howells return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); 9981da177e4SLinus Torvalds } 9991da177e4SLinus Torvalds 10001da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 10011da177e4SLinus Torvalds .owner = THIS_MODULE, 10021da177e4SLinus Torvalds .name = "hostfs", 10031da177e4SLinus Torvalds .get_sb = hostfs_read_sb, 10041da177e4SLinus Torvalds .kill_sb = kill_anon_super, 10051da177e4SLinus Torvalds .fs_flags = 0, 10061da177e4SLinus Torvalds }; 10071da177e4SLinus Torvalds 10081da177e4SLinus Torvalds static int __init init_hostfs(void) 10091da177e4SLinus Torvalds { 1010f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 10111da177e4SLinus Torvalds } 10121da177e4SLinus Torvalds 10131da177e4SLinus Torvalds static void __exit exit_hostfs(void) 10141da177e4SLinus Torvalds { 10151da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 10161da177e4SLinus Torvalds } 10171da177e4SLinus Torvalds 10181da177e4SLinus Torvalds module_init(init_hostfs) 10191da177e4SLinus Torvalds module_exit(exit_hostfs) 10201da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1021