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> 145a0e3ad6STejun Heo #include <linux/slab.h> 15dd2cc4dfSMiklos Szeredi #include <linux/seq_file.h> 166966a977SJiri Kosina #include <linux/mount.h> 171da177e4SLinus Torvalds #include "hostfs.h" 181da177e4SLinus Torvalds #include "init.h" 1984b3db04SJeff Dike #include "kern.h" 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds struct hostfs_inode_info { 221da177e4SLinus Torvalds int fd; 23aeb5d727SAl Viro fmode_t mode; 241da177e4SLinus Torvalds struct inode vfs_inode; 251da177e4SLinus Torvalds }; 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 281da177e4SLinus Torvalds { 29f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode); 301da177e4SLinus Torvalds } 311da177e4SLinus Torvalds 32680b0da9SJosef Sipek #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) 331da177e4SLinus Torvalds 34e16404edSAl Viro static int hostfs_d_delete(struct dentry *dentry) 351da177e4SLinus Torvalds { 36f1adc05eSJeff Dike return 1; 371da177e4SLinus Torvalds } 381da177e4SLinus Torvalds 39e16404edSAl Viro static const struct dentry_operations hostfs_dentry_ops = { 401da177e4SLinus Torvalds .d_delete = hostfs_d_delete, 411da177e4SLinus Torvalds }; 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 44a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 451da177e4SLinus Torvalds static int append = 0; 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds #define HOSTFS_SUPER_MAGIC 0x00c0ffee 481da177e4SLinus Torvalds 4992e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 5092e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 51f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops; 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds #ifndef MODULE 541da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 551da177e4SLinus Torvalds { 561da177e4SLinus Torvalds char *ptr; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds ptr = strchr(options, ','); 591da177e4SLinus Torvalds if (ptr != NULL) 601da177e4SLinus Torvalds *ptr++ = '\0'; 611da177e4SLinus Torvalds if (*options != '\0') 621da177e4SLinus Torvalds root_ino = options; 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds options = ptr; 651da177e4SLinus Torvalds while (options) { 661da177e4SLinus Torvalds ptr = strchr(options, ','); 671da177e4SLinus Torvalds if (ptr != NULL) 681da177e4SLinus Torvalds *ptr++ = '\0'; 691da177e4SLinus Torvalds if (*options != '\0') { 701da177e4SLinus Torvalds if (!strcmp(options, "append")) 711da177e4SLinus Torvalds append = 1; 721da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 731da177e4SLinus Torvalds options); 741da177e4SLinus Torvalds } 751da177e4SLinus Torvalds options = ptr; 761da177e4SLinus Torvalds } 77f1adc05eSJeff Dike return 0; 781da177e4SLinus Torvalds } 791da177e4SLinus Torvalds 801da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 811da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 821da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 831da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 841da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 851da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 861da177e4SLinus Torvalds " it.\n" 871da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 881da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 891da177e4SLinus Torvalds ); 901da177e4SLinus Torvalds #endif 911da177e4SLinus Torvalds 921da177e4SLinus Torvalds static char *dentry_name(struct dentry *dentry, int extra) 931da177e4SLinus Torvalds { 941da177e4SLinus Torvalds struct dentry *parent; 951da177e4SLinus Torvalds char *root, *name; 961da177e4SLinus Torvalds int len; 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds len = 0; 991da177e4SLinus Torvalds parent = dentry; 1001da177e4SLinus Torvalds while (parent->d_parent != parent) { 1011da177e4SLinus Torvalds len += parent->d_name.len + 1; 1021da177e4SLinus Torvalds parent = parent->d_parent; 1031da177e4SLinus Torvalds } 1041da177e4SLinus Torvalds 105601d2c38SAl Viro root = parent->d_sb->s_fs_info; 1061da177e4SLinus Torvalds len += strlen(root); 1071da177e4SLinus Torvalds name = kmalloc(len + extra + 1, GFP_KERNEL); 108f1adc05eSJeff Dike if (name == NULL) 109f1adc05eSJeff Dike return NULL; 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds name[len] = '\0'; 1121da177e4SLinus Torvalds parent = dentry; 1131da177e4SLinus Torvalds while (parent->d_parent != parent) { 1141da177e4SLinus Torvalds len -= parent->d_name.len + 1; 1151da177e4SLinus Torvalds name[len] = '/'; 1161da177e4SLinus Torvalds strncpy(&name[len + 1], parent->d_name.name, 1171da177e4SLinus Torvalds parent->d_name.len); 1181da177e4SLinus Torvalds parent = parent->d_parent; 1191da177e4SLinus Torvalds } 1201da177e4SLinus Torvalds strncpy(name, root, strlen(root)); 121f1adc05eSJeff Dike return name; 1221da177e4SLinus Torvalds } 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds static char *inode_name(struct inode *ino, int extra) 1251da177e4SLinus Torvalds { 1261da177e4SLinus Torvalds struct dentry *dentry; 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); 129f1adc05eSJeff Dike return dentry_name(dentry, extra); 1301da177e4SLinus Torvalds } 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds static int read_name(struct inode *ino, char *name) 1331da177e4SLinus Torvalds { 13484b3db04SJeff Dike /* 13584b3db04SJeff Dike * The non-int inode fields are copied into ints by stat_file and 1361da177e4SLinus Torvalds * then copied into the inode because passing the actual pointers 1371da177e4SLinus Torvalds * in and having them treated as int * breaks on big-endian machines 1381da177e4SLinus Torvalds */ 1391da177e4SLinus Torvalds int err; 1401da177e4SLinus Torvalds int i_mode, i_nlink, i_blksize; 1411da177e4SLinus Torvalds unsigned long long i_size; 1421da177e4SLinus Torvalds unsigned long long i_ino; 1431da177e4SLinus Torvalds unsigned long long i_blocks; 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvalds err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, 1461da177e4SLinus Torvalds &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, 1475822b7faSAlberto Bertogli &ino->i_ctime, &i_blksize, &i_blocks, -1); 1481da177e4SLinus Torvalds if (err) 149f1adc05eSJeff Dike return err; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds ino->i_ino = i_ino; 1521da177e4SLinus Torvalds ino->i_mode = i_mode; 1531da177e4SLinus Torvalds ino->i_nlink = i_nlink; 1541da177e4SLinus Torvalds ino->i_size = i_size; 1551da177e4SLinus Torvalds ino->i_blocks = i_blocks; 156f1adc05eSJeff Dike return 0; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds static char *follow_link(char *link) 1601da177e4SLinus Torvalds { 1611da177e4SLinus Torvalds int len, n; 1621da177e4SLinus Torvalds char *name, *resolved, *end; 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds len = 64; 1651da177e4SLinus Torvalds while (1) { 1661da177e4SLinus Torvalds n = -ENOMEM; 1671da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1681da177e4SLinus Torvalds if (name == NULL) 1691da177e4SLinus Torvalds goto out; 1701da177e4SLinus Torvalds 171ea7e743eSWANG Cong n = hostfs_do_readlink(link, name, len); 1721da177e4SLinus Torvalds if (n < len) 1731da177e4SLinus Torvalds break; 1741da177e4SLinus Torvalds len *= 2; 1751da177e4SLinus Torvalds kfree(name); 1761da177e4SLinus Torvalds } 1771da177e4SLinus Torvalds if (n < 0) 1781da177e4SLinus Torvalds goto out_free; 1791da177e4SLinus Torvalds 1801da177e4SLinus Torvalds if (*name == '/') 181f1adc05eSJeff Dike return name; 1821da177e4SLinus Torvalds 1831da177e4SLinus Torvalds end = strrchr(link, '/'); 1841da177e4SLinus Torvalds if (end == NULL) 185f1adc05eSJeff Dike return name; 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds *(end + 1) = '\0'; 1881da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 1911da177e4SLinus Torvalds if (resolved == NULL) { 1921da177e4SLinus Torvalds n = -ENOMEM; 1931da177e4SLinus Torvalds goto out_free; 1941da177e4SLinus Torvalds } 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 1971da177e4SLinus Torvalds kfree(name); 1981da177e4SLinus Torvalds kfree(link); 199f1adc05eSJeff Dike return resolved; 2001da177e4SLinus Torvalds 2011da177e4SLinus Torvalds out_free: 2021da177e4SLinus Torvalds kfree(name); 2031da177e4SLinus Torvalds out: 204f1adc05eSJeff Dike return ERR_PTR(n); 2051da177e4SLinus Torvalds } 2061da177e4SLinus Torvalds 2070a370e5dSDavid Howells static struct inode *hostfs_iget(struct super_block *sb) 2080a370e5dSDavid Howells { 20952b209f7SAl Viro struct inode *inode = new_inode(sb); 2100a370e5dSDavid Howells if (!inode) 2110a370e5dSDavid Howells return ERR_PTR(-ENOMEM); 2120a370e5dSDavid Howells return inode; 2130a370e5dSDavid Howells } 2140a370e5dSDavid Howells 215726c3342SDavid Howells int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 2161da177e4SLinus Torvalds { 21784b3db04SJeff Dike /* 21884b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 2191da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 2201da177e4SLinus Torvalds * so we convert them here 2211da177e4SLinus Torvalds */ 2221da177e4SLinus Torvalds int err; 2231da177e4SLinus Torvalds long long f_blocks; 2241da177e4SLinus Torvalds long long f_bfree; 2251da177e4SLinus Torvalds long long f_bavail; 2261da177e4SLinus Torvalds long long f_files; 2271da177e4SLinus Torvalds long long f_ffree; 2281da177e4SLinus Torvalds 229601d2c38SAl Viro err = do_statfs(dentry->d_sb->s_fs_info, 2301da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2311da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2321da177e4SLinus Torvalds &sf->f_namelen, sf->f_spare); 233f1adc05eSJeff Dike if (err) 234f1adc05eSJeff Dike return err; 2351da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2361da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2371da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2381da177e4SLinus Torvalds sf->f_files = f_files; 2391da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2401da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 241f1adc05eSJeff Dike return 0; 2421da177e4SLinus Torvalds } 2431da177e4SLinus Torvalds 2441da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2451da177e4SLinus Torvalds { 2461da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2471da177e4SLinus Torvalds 248601d2c38SAl Viro hi = kzalloc(sizeof(*hi), GFP_KERNEL); 2491da177e4SLinus Torvalds if (hi == NULL) 250f1adc05eSJeff Dike return NULL; 251601d2c38SAl Viro hi->fd = -1; 2521da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 253f1adc05eSJeff Dike return &hi->vfs_inode; 2541da177e4SLinus Torvalds } 2551da177e4SLinus Torvalds 256e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode) 2571da177e4SLinus Torvalds { 258fef26658SMark Fasheh truncate_inode_pages(&inode->i_data, 0); 259e971a6d7SAl Viro end_writeback(inode); 2601da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2611da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2621da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2631da177e4SLinus Torvalds } 2641da177e4SLinus Torvalds } 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2671da177e4SLinus Torvalds { 2681da177e4SLinus Torvalds kfree(HOSTFS_I(inode)); 2691da177e4SLinus Torvalds } 2701da177e4SLinus Torvalds 271dd2cc4dfSMiklos Szeredi static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 272dd2cc4dfSMiklos Szeredi { 273601d2c38SAl Viro const char *root_path = vfs->mnt_sb->s_fs_info; 274dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1; 275dd2cc4dfSMiklos Szeredi 276dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset) 277dd2cc4dfSMiklos Szeredi seq_printf(seq, ",%s", root_path + offset); 278dd2cc4dfSMiklos Szeredi 279dd2cc4dfSMiklos Szeredi return 0; 280dd2cc4dfSMiklos Szeredi } 281dd2cc4dfSMiklos Szeredi 282ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 2831da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 2841da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 285e971a6d7SAl Viro .evict_inode = hostfs_evict_inode, 2861da177e4SLinus Torvalds .statfs = hostfs_statfs, 287dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options, 2881da177e4SLinus Torvalds }; 2891da177e4SLinus Torvalds 2901da177e4SLinus Torvalds int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) 2911da177e4SLinus Torvalds { 2921da177e4SLinus Torvalds void *dir; 2931da177e4SLinus Torvalds char *name; 2941da177e4SLinus Torvalds unsigned long long next, ino; 2951da177e4SLinus Torvalds int error, len; 2961da177e4SLinus Torvalds 297680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 298f1adc05eSJeff Dike if (name == NULL) 299f1adc05eSJeff Dike return -ENOMEM; 3001da177e4SLinus Torvalds dir = open_dir(name, &error); 3011da177e4SLinus Torvalds kfree(name); 302f1adc05eSJeff Dike if (dir == NULL) 303f1adc05eSJeff Dike return -error; 3041da177e4SLinus Torvalds next = file->f_pos; 3051da177e4SLinus Torvalds while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { 3061da177e4SLinus Torvalds error = (*filldir)(ent, name, len, file->f_pos, 3071da177e4SLinus Torvalds ino, DT_UNKNOWN); 3081da177e4SLinus Torvalds if (error) break; 3091da177e4SLinus Torvalds file->f_pos = next; 3101da177e4SLinus Torvalds } 3111da177e4SLinus Torvalds close_dir(dir); 312f1adc05eSJeff Dike return 0; 3131da177e4SLinus Torvalds } 3141da177e4SLinus Torvalds 3151da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 3161da177e4SLinus Torvalds { 3171da177e4SLinus Torvalds char *name; 318aeb5d727SAl Viro fmode_t mode = 0; 319aeb5d727SAl Viro int r = 0, w = 0, fd; 3201da177e4SLinus Torvalds 3211da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3221da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode) 323f1adc05eSJeff Dike return 0; 3241da177e4SLinus Torvalds 32584b3db04SJeff Dike /* 32684b3db04SJeff Dike * The file may already have been opened, but with the wrong access, 3271da177e4SLinus Torvalds * so this resets things and reopens the file with the new access. 3281da177e4SLinus Torvalds */ 3291da177e4SLinus Torvalds if (HOSTFS_I(ino)->fd != -1) { 3301da177e4SLinus Torvalds close_file(&HOSTFS_I(ino)->fd); 3311da177e4SLinus Torvalds HOSTFS_I(ino)->fd = -1; 3321da177e4SLinus Torvalds } 3331da177e4SLinus Torvalds 3341da177e4SLinus Torvalds HOSTFS_I(ino)->mode |= mode; 3351da177e4SLinus Torvalds if (HOSTFS_I(ino)->mode & FMODE_READ) 3361da177e4SLinus Torvalds r = 1; 3371da177e4SLinus Torvalds if (HOSTFS_I(ino)->mode & FMODE_WRITE) 3381da177e4SLinus Torvalds w = 1; 3391da177e4SLinus Torvalds if (w) 3401da177e4SLinus Torvalds r = 1; 3411da177e4SLinus Torvalds 342680b0da9SJosef Sipek name = dentry_name(file->f_path.dentry, 0); 3431da177e4SLinus Torvalds if (name == NULL) 344f1adc05eSJeff Dike return -ENOMEM; 3451da177e4SLinus Torvalds 3461da177e4SLinus Torvalds fd = open_file(name, r, w, append); 3471da177e4SLinus Torvalds kfree(name); 348f1adc05eSJeff Dike if (fd < 0) 349f1adc05eSJeff Dike return fd; 3501da177e4SLinus Torvalds FILE_HOSTFS_I(file)->fd = fd; 3511da177e4SLinus Torvalds 352f1adc05eSJeff Dike return 0; 3531da177e4SLinus Torvalds } 3541da177e4SLinus Torvalds 3557ea80859SChristoph Hellwig int hostfs_fsync(struct file *file, int datasync) 3561da177e4SLinus Torvalds { 3577ea80859SChristoph Hellwig return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); 3581da177e4SLinus Torvalds } 3591da177e4SLinus Torvalds 3604b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3611da177e4SLinus Torvalds .llseek = generic_file_llseek, 362543ade1fSBadari Pulavarty .read = do_sync_read, 3635ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3641da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3651da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 366543ade1fSBadari Pulavarty .write = do_sync_write, 3671da177e4SLinus Torvalds .mmap = generic_file_mmap, 3681da177e4SLinus Torvalds .open = hostfs_file_open, 3691da177e4SLinus Torvalds .release = NULL, 3701da177e4SLinus Torvalds .fsync = hostfs_fsync, 3711da177e4SLinus Torvalds }; 3721da177e4SLinus Torvalds 3734b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 3741da177e4SLinus Torvalds .llseek = generic_file_llseek, 3751da177e4SLinus Torvalds .readdir = hostfs_readdir, 3761da177e4SLinus Torvalds .read = generic_read_dir, 3771da177e4SLinus Torvalds }; 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 3801da177e4SLinus Torvalds { 3811da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 3821da177e4SLinus Torvalds struct inode *inode = mapping->host; 3831da177e4SLinus Torvalds char *buffer; 3841da177e4SLinus Torvalds unsigned long long base; 3851da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 3861da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 3871da177e4SLinus Torvalds int err; 3881da177e4SLinus Torvalds 3891da177e4SLinus Torvalds if (page->index >= end_index) 3901da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 3911da177e4SLinus Torvalds 3921da177e4SLinus Torvalds buffer = kmap(page); 3931da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 3941da177e4SLinus Torvalds 3951da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 3961da177e4SLinus Torvalds if (err != count) { 3971da177e4SLinus Torvalds ClearPageUptodate(page); 3981da177e4SLinus Torvalds goto out; 3991da177e4SLinus Torvalds } 4001da177e4SLinus Torvalds 4011da177e4SLinus Torvalds if (base > inode->i_size) 4021da177e4SLinus Torvalds inode->i_size = base; 4031da177e4SLinus Torvalds 4041da177e4SLinus Torvalds if (PageError(page)) 4051da177e4SLinus Torvalds ClearPageError(page); 4061da177e4SLinus Torvalds err = 0; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds out: 4091da177e4SLinus Torvalds kunmap(page); 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds unlock_page(page); 4121da177e4SLinus Torvalds return err; 4131da177e4SLinus Torvalds } 4141da177e4SLinus Torvalds 4151da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4161da177e4SLinus Torvalds { 4171da177e4SLinus Torvalds char *buffer; 4181da177e4SLinus Torvalds long long start; 4191da177e4SLinus Torvalds int err = 0; 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4221da177e4SLinus Torvalds buffer = kmap(page); 4231da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4241da177e4SLinus Torvalds PAGE_CACHE_SIZE); 42584b3db04SJeff Dike if (err < 0) 42684b3db04SJeff Dike goto out; 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); 4291da177e4SLinus Torvalds 4301da177e4SLinus Torvalds flush_dcache_page(page); 4311da177e4SLinus Torvalds SetPageUptodate(page); 4321da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 4331da177e4SLinus Torvalds err = 0; 4341da177e4SLinus Torvalds out: 4351da177e4SLinus Torvalds kunmap(page); 4361da177e4SLinus Torvalds unlock_page(page); 437f1adc05eSJeff Dike return err; 4381da177e4SLinus Torvalds } 4391da177e4SLinus Torvalds 440ae361ff4SNick Piggin int hostfs_write_begin(struct file *file, struct address_space *mapping, 441ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 442ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4431da177e4SLinus Torvalds { 444ae361ff4SNick Piggin pgoff_t index = pos >> PAGE_CACHE_SHIFT; 445ae361ff4SNick Piggin 44654566b2cSNick Piggin *pagep = grab_cache_page_write_begin(mapping, index, flags); 447ae361ff4SNick Piggin if (!*pagep) 448ae361ff4SNick Piggin return -ENOMEM; 449ae361ff4SNick Piggin return 0; 450ae361ff4SNick Piggin } 451ae361ff4SNick Piggin 452ae361ff4SNick Piggin int hostfs_write_end(struct file *file, struct address_space *mapping, 453ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 454ae361ff4SNick Piggin struct page *page, void *fsdata) 455ae361ff4SNick Piggin { 456ae361ff4SNick Piggin struct inode *inode = mapping->host; 457ae361ff4SNick Piggin void *buffer; 458ae361ff4SNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 4591da177e4SLinus Torvalds int err; 4601da177e4SLinus Torvalds 4611da177e4SLinus Torvalds buffer = kmap(page); 462ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4631da177e4SLinus Torvalds kunmap(page); 4641da177e4SLinus Torvalds 465ae361ff4SNick Piggin if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) 466ae361ff4SNick Piggin SetPageUptodate(page); 4671da177e4SLinus Torvalds 46884b3db04SJeff Dike /* 46984b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 470ae361ff4SNick Piggin * i_size against the last byte written. 471ae361ff4SNick Piggin */ 472ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 473ae361ff4SNick Piggin inode->i_size = pos; 474ae361ff4SNick Piggin unlock_page(page); 475ae361ff4SNick Piggin page_cache_release(page); 47630f04a4eSPaolo 'Blaisorblade' Giarrusso 477f1adc05eSJeff Dike return err; 4781da177e4SLinus Torvalds } 4791da177e4SLinus Torvalds 480f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 4811da177e4SLinus Torvalds .writepage = hostfs_writepage, 4821da177e4SLinus Torvalds .readpage = hostfs_readpage, 483ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 484ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 485ae361ff4SNick Piggin .write_end = hostfs_write_end, 4861da177e4SLinus Torvalds }; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds static int init_inode(struct inode *inode, struct dentry *dentry) 4891da177e4SLinus Torvalds { 4901da177e4SLinus Torvalds char *name; 4911da177e4SLinus Torvalds int type, err = -ENOMEM; 4921da177e4SLinus Torvalds int maj, min; 4931da177e4SLinus Torvalds dev_t rdev = 0; 4941da177e4SLinus Torvalds 4951da177e4SLinus Torvalds if (dentry) { 4961da177e4SLinus Torvalds name = dentry_name(dentry, 0); 4971da177e4SLinus Torvalds if (name == NULL) 4981da177e4SLinus Torvalds goto out; 4991da177e4SLinus Torvalds type = file_type(name, &maj, &min); 5001da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5011da177e4SLinus Torvalds rdev = MKDEV(maj, min); 5021da177e4SLinus Torvalds kfree(name); 5031da177e4SLinus Torvalds } 5041da177e4SLinus Torvalds else type = OS_TYPE_DIR; 5051da177e4SLinus Torvalds 5061da177e4SLinus Torvalds err = 0; 5071da177e4SLinus Torvalds if (type == OS_TYPE_SYMLINK) 5081da177e4SLinus Torvalds inode->i_op = &page_symlink_inode_operations; 5091da177e4SLinus Torvalds else if (type == OS_TYPE_DIR) 5101da177e4SLinus Torvalds inode->i_op = &hostfs_dir_iops; 5111da177e4SLinus Torvalds else inode->i_op = &hostfs_iops; 5121da177e4SLinus Torvalds 5131da177e4SLinus Torvalds if (type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; 5141da177e4SLinus Torvalds else inode->i_fop = &hostfs_file_fops; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds if (type == OS_TYPE_SYMLINK) 5171da177e4SLinus Torvalds inode->i_mapping->a_ops = &hostfs_link_aops; 5181da177e4SLinus Torvalds else inode->i_mapping->a_ops = &hostfs_aops; 5191da177e4SLinus Torvalds 5201da177e4SLinus Torvalds switch (type) { 5211da177e4SLinus Torvalds case OS_TYPE_CHARDEV: 5221da177e4SLinus Torvalds init_special_inode(inode, S_IFCHR, rdev); 5231da177e4SLinus Torvalds break; 5241da177e4SLinus Torvalds case OS_TYPE_BLOCKDEV: 5251da177e4SLinus Torvalds init_special_inode(inode, S_IFBLK, rdev); 5261da177e4SLinus Torvalds break; 5271da177e4SLinus Torvalds case OS_TYPE_FIFO: 5281da177e4SLinus Torvalds init_special_inode(inode, S_IFIFO, 0); 5291da177e4SLinus Torvalds break; 5301da177e4SLinus Torvalds case OS_TYPE_SOCK: 5311da177e4SLinus Torvalds init_special_inode(inode, S_IFSOCK, 0); 5321da177e4SLinus Torvalds break; 5331da177e4SLinus Torvalds } 5341da177e4SLinus Torvalds out: 535f1adc05eSJeff Dike return err; 5361da177e4SLinus Torvalds } 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvalds int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, 5391da177e4SLinus Torvalds struct nameidata *nd) 5401da177e4SLinus Torvalds { 5411da177e4SLinus Torvalds struct inode *inode; 5421da177e4SLinus Torvalds char *name; 5431da177e4SLinus Torvalds int error, fd; 5441da177e4SLinus Torvalds 5450a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 5460a370e5dSDavid Howells if (IS_ERR(inode)) { 5470a370e5dSDavid Howells error = PTR_ERR(inode); 54884b3db04SJeff Dike goto out; 5490a370e5dSDavid Howells } 5501da177e4SLinus Torvalds 5511da177e4SLinus Torvalds error = init_inode(inode, dentry); 5521da177e4SLinus Torvalds if (error) 5531da177e4SLinus Torvalds goto out_put; 5541da177e4SLinus Torvalds 5551da177e4SLinus Torvalds error = -ENOMEM; 5561da177e4SLinus Torvalds name = dentry_name(dentry, 0); 5571da177e4SLinus Torvalds if (name == NULL) 5581da177e4SLinus Torvalds goto out_put; 5591da177e4SLinus Torvalds 5601da177e4SLinus Torvalds fd = file_create(name, 5611da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 5621da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 5631da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 5641da177e4SLinus Torvalds if (fd < 0) 5651da177e4SLinus Torvalds error = fd; 5661da177e4SLinus Torvalds else error = read_name(inode, name); 5671da177e4SLinus Torvalds 5681da177e4SLinus Torvalds kfree(name); 5691da177e4SLinus Torvalds if (error) 5701da177e4SLinus Torvalds goto out_put; 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5731da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 5741da177e4SLinus Torvalds d_instantiate(dentry, inode); 575f1adc05eSJeff Dike return 0; 5761da177e4SLinus Torvalds 5771da177e4SLinus Torvalds out_put: 5781da177e4SLinus Torvalds iput(inode); 5791da177e4SLinus Torvalds out: 580f1adc05eSJeff Dike return error; 5811da177e4SLinus Torvalds } 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 5841da177e4SLinus Torvalds struct nameidata *nd) 5851da177e4SLinus Torvalds { 5861da177e4SLinus Torvalds struct inode *inode; 5871da177e4SLinus Torvalds char *name; 5881da177e4SLinus Torvalds int err; 5891da177e4SLinus Torvalds 5900a370e5dSDavid Howells inode = hostfs_iget(ino->i_sb); 5910a370e5dSDavid Howells if (IS_ERR(inode)) { 5920a370e5dSDavid Howells err = PTR_ERR(inode); 5931da177e4SLinus Torvalds goto out; 5940a370e5dSDavid Howells } 5951da177e4SLinus Torvalds 5961da177e4SLinus Torvalds err = init_inode(inode, dentry); 5971da177e4SLinus Torvalds if (err) 5981da177e4SLinus Torvalds goto out_put; 5991da177e4SLinus Torvalds 6001da177e4SLinus Torvalds err = -ENOMEM; 6011da177e4SLinus Torvalds name = dentry_name(dentry, 0); 6021da177e4SLinus Torvalds if (name == NULL) 6031da177e4SLinus Torvalds goto out_put; 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds err = read_name(inode, name); 6061da177e4SLinus Torvalds kfree(name); 6071da177e4SLinus Torvalds if (err == -ENOENT) { 6081da177e4SLinus Torvalds iput(inode); 6091da177e4SLinus Torvalds inode = NULL; 6101da177e4SLinus Torvalds } 6111da177e4SLinus Torvalds else if (err) 6121da177e4SLinus Torvalds goto out_put; 6131da177e4SLinus Torvalds 6141da177e4SLinus Torvalds d_add(dentry, inode); 6151da177e4SLinus Torvalds dentry->d_op = &hostfs_dentry_ops; 616f1adc05eSJeff Dike return NULL; 6171da177e4SLinus Torvalds 6181da177e4SLinus Torvalds out_put: 6191da177e4SLinus Torvalds iput(inode); 6201da177e4SLinus Torvalds out: 621f1adc05eSJeff Dike return ERR_PTR(err); 6221da177e4SLinus Torvalds } 6231da177e4SLinus Torvalds 6241da177e4SLinus Torvalds static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) 6251da177e4SLinus Torvalds { 6261da177e4SLinus Torvalds char *file; 6271da177e4SLinus Torvalds int len; 6281da177e4SLinus Torvalds 6291da177e4SLinus Torvalds file = inode_name(ino, dentry->d_name.len + 1); 630f1adc05eSJeff Dike if (file == NULL) 631f1adc05eSJeff Dike return NULL; 6321da177e4SLinus Torvalds strcat(file, "/"); 6331da177e4SLinus Torvalds len = strlen(file); 6341da177e4SLinus Torvalds strncat(file, dentry->d_name.name, dentry->d_name.len); 6351da177e4SLinus Torvalds file[len + dentry->d_name.len] = '\0'; 636f1adc05eSJeff Dike return file; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds 6391da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6401da177e4SLinus Torvalds { 6411da177e4SLinus Torvalds char *from_name, *to_name; 6421da177e4SLinus Torvalds int err; 6431da177e4SLinus Torvalds 6441da177e4SLinus Torvalds if ((from_name = inode_dentry_name(ino, from)) == NULL) 645f1adc05eSJeff Dike return -ENOMEM; 6461da177e4SLinus Torvalds to_name = dentry_name(to, 0); 6471da177e4SLinus Torvalds if (to_name == NULL) { 6481da177e4SLinus Torvalds kfree(from_name); 649f1adc05eSJeff Dike return -ENOMEM; 6501da177e4SLinus Torvalds } 6511da177e4SLinus Torvalds err = link_file(to_name, from_name); 6521da177e4SLinus Torvalds kfree(from_name); 6531da177e4SLinus Torvalds kfree(to_name); 654f1adc05eSJeff Dike return err; 6551da177e4SLinus Torvalds } 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6581da177e4SLinus Torvalds { 6591da177e4SLinus Torvalds char *file; 6601da177e4SLinus Torvalds int err; 6611da177e4SLinus Torvalds 662f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 663f1adc05eSJeff Dike return -ENOMEM; 6641da177e4SLinus Torvalds if (append) 665f1adc05eSJeff Dike return -EPERM; 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds err = unlink_file(file); 6681da177e4SLinus Torvalds kfree(file); 669f1adc05eSJeff Dike return err; 6701da177e4SLinus Torvalds } 6711da177e4SLinus Torvalds 6721da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 6731da177e4SLinus Torvalds { 6741da177e4SLinus Torvalds char *file; 6751da177e4SLinus Torvalds int err; 6761da177e4SLinus Torvalds 677f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 678f1adc05eSJeff Dike return -ENOMEM; 6791da177e4SLinus Torvalds err = make_symlink(file, to); 6801da177e4SLinus Torvalds kfree(file); 681f1adc05eSJeff Dike return err; 6821da177e4SLinus Torvalds } 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) 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 err = do_mkdir(file, mode); 6921da177e4SLinus Torvalds kfree(file); 693f1adc05eSJeff Dike return err; 6941da177e4SLinus Torvalds } 6951da177e4SLinus Torvalds 6961da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 6971da177e4SLinus Torvalds { 6981da177e4SLinus Torvalds char *file; 6991da177e4SLinus Torvalds int err; 7001da177e4SLinus Torvalds 701f1adc05eSJeff Dike if ((file = inode_dentry_name(ino, dentry)) == NULL) 702f1adc05eSJeff Dike return -ENOMEM; 7031da177e4SLinus Torvalds err = do_rmdir(file); 7041da177e4SLinus Torvalds kfree(file); 705f1adc05eSJeff Dike return err; 7061da177e4SLinus Torvalds } 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 7091da177e4SLinus Torvalds { 7101da177e4SLinus Torvalds struct inode *inode; 7111da177e4SLinus Torvalds char *name; 7120a370e5dSDavid Howells int err; 7131da177e4SLinus Torvalds 7140a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 7150a370e5dSDavid Howells if (IS_ERR(inode)) { 7160a370e5dSDavid Howells err = PTR_ERR(inode); 7171da177e4SLinus Torvalds goto out; 7180a370e5dSDavid Howells } 7191da177e4SLinus Torvalds 7201da177e4SLinus Torvalds err = init_inode(inode, dentry); 7211da177e4SLinus Torvalds if (err) 7221da177e4SLinus Torvalds goto out_put; 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds err = -ENOMEM; 7251da177e4SLinus Torvalds name = dentry_name(dentry, 0); 7261da177e4SLinus Torvalds if (name == NULL) 7271da177e4SLinus Torvalds goto out_put; 7281da177e4SLinus Torvalds 7291da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 73088f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 7311da177e4SLinus Torvalds if (err) 7321da177e4SLinus Torvalds goto out_free; 7331da177e4SLinus Torvalds 7341da177e4SLinus Torvalds err = read_name(inode, name); 7351da177e4SLinus Torvalds kfree(name); 7361da177e4SLinus Torvalds if (err) 7371da177e4SLinus Torvalds goto out_put; 7381da177e4SLinus Torvalds 7391da177e4SLinus Torvalds d_instantiate(dentry, inode); 740f1adc05eSJeff Dike return 0; 7411da177e4SLinus Torvalds 7421da177e4SLinus Torvalds out_free: 7431da177e4SLinus Torvalds kfree(name); 7441da177e4SLinus Torvalds out_put: 7451da177e4SLinus Torvalds iput(inode); 7461da177e4SLinus Torvalds out: 747f1adc05eSJeff Dike return err; 7481da177e4SLinus Torvalds } 7491da177e4SLinus Torvalds 7501da177e4SLinus Torvalds int hostfs_rename(struct inode *from_ino, struct dentry *from, 7511da177e4SLinus Torvalds struct inode *to_ino, struct dentry *to) 7521da177e4SLinus Torvalds { 7531da177e4SLinus Torvalds char *from_name, *to_name; 7541da177e4SLinus Torvalds int err; 7551da177e4SLinus Torvalds 7561da177e4SLinus Torvalds if ((from_name = inode_dentry_name(from_ino, from)) == NULL) 757f1adc05eSJeff Dike return -ENOMEM; 7581da177e4SLinus Torvalds if ((to_name = inode_dentry_name(to_ino, to)) == NULL) { 7591da177e4SLinus Torvalds kfree(from_name); 760f1adc05eSJeff Dike return -ENOMEM; 7611da177e4SLinus Torvalds } 7621da177e4SLinus Torvalds err = rename_file(from_name, to_name); 7631da177e4SLinus Torvalds kfree(from_name); 7641da177e4SLinus Torvalds kfree(to_name); 765f1adc05eSJeff Dike return err; 7661da177e4SLinus Torvalds } 7671da177e4SLinus Torvalds 768e6305c43SAl Viro int hostfs_permission(struct inode *ino, int desired) 7691da177e4SLinus Torvalds { 7701da177e4SLinus Torvalds char *name; 7711da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7721da177e4SLinus Torvalds 7731da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7741da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7751da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 7761da177e4SLinus Torvalds name = inode_name(ino, 0); 777f1adc05eSJeff Dike if (name == NULL) 778f1adc05eSJeff Dike return -ENOMEM; 7791da177e4SLinus Torvalds 7801da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 7811da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 7821da177e4SLinus Torvalds err = 0; 7831da177e4SLinus Torvalds else 7841da177e4SLinus Torvalds err = access_file(name, r, w, x); 7851da177e4SLinus Torvalds kfree(name); 7861da177e4SLinus Torvalds if (!err) 7871da177e4SLinus Torvalds err = generic_permission(ino, desired, NULL); 7881da177e4SLinus Torvalds return err; 7891da177e4SLinus Torvalds } 7901da177e4SLinus Torvalds 7911da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 7921da177e4SLinus Torvalds { 7931025774cSChristoph Hellwig struct inode *inode = dentry->d_inode; 7941da177e4SLinus Torvalds struct hostfs_iattr attrs; 7951da177e4SLinus Torvalds char *name; 7961da177e4SLinus Torvalds int err; 7971da177e4SLinus Torvalds 7981025774cSChristoph Hellwig int fd = HOSTFS_I(inode)->fd; 7995822b7faSAlberto Bertogli 8001025774cSChristoph Hellwig err = inode_change_ok(inode, attr); 8011da177e4SLinus Torvalds if (err) 8021da177e4SLinus Torvalds return err; 8031da177e4SLinus Torvalds 8041da177e4SLinus Torvalds if (append) 8051da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8061da177e4SLinus Torvalds 8071da177e4SLinus Torvalds attrs.ia_valid = 0; 8081da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) { 8091da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8101da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8111da177e4SLinus Torvalds } 8121da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) { 8131da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 8141da177e4SLinus Torvalds attrs.ia_uid = attr->ia_uid; 8151da177e4SLinus Torvalds } 8161da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8171da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 8181da177e4SLinus Torvalds attrs.ia_gid = attr->ia_gid; 8191da177e4SLinus Torvalds } 8201da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) { 8211da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8221da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8231da177e4SLinus Torvalds } 8241da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) { 8251da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8261da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8271da177e4SLinus Torvalds } 8281da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8291da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8301da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8311da177e4SLinus Torvalds } 8321da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8331da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8341da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 8351da177e4SLinus Torvalds } 8361da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) { 8371da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8381da177e4SLinus Torvalds } 8391da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) { 8401da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8411da177e4SLinus Torvalds } 8421da177e4SLinus Torvalds name = dentry_name(dentry, 0); 843f1adc05eSJeff Dike if (name == NULL) 844f1adc05eSJeff Dike return -ENOMEM; 8455822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 8461da177e4SLinus Torvalds kfree(name); 8471da177e4SLinus Torvalds if (err) 848f1adc05eSJeff Dike return err; 8491da177e4SLinus Torvalds 8501025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 8511025774cSChristoph Hellwig attr->ia_size != i_size_read(inode)) { 8521025774cSChristoph Hellwig int error; 8531025774cSChristoph Hellwig 8541025774cSChristoph Hellwig error = vmtruncate(inode, attr->ia_size); 8551025774cSChristoph Hellwig if (err) 8561025774cSChristoph Hellwig return err; 8571025774cSChristoph Hellwig } 8581025774cSChristoph Hellwig 8591025774cSChristoph Hellwig setattr_copy(inode, attr); 8601025774cSChristoph Hellwig mark_inode_dirty(inode); 8611025774cSChristoph Hellwig return 0; 8621da177e4SLinus Torvalds } 8631da177e4SLinus Torvalds 86492e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8651da177e4SLinus Torvalds .create = hostfs_create, 8661da177e4SLinus Torvalds .link = hostfs_link, 8671da177e4SLinus Torvalds .unlink = hostfs_unlink, 8681da177e4SLinus Torvalds .symlink = hostfs_symlink, 8691da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8701da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8711da177e4SLinus Torvalds .mknod = hostfs_mknod, 8721da177e4SLinus Torvalds .rename = hostfs_rename, 8731da177e4SLinus Torvalds .permission = hostfs_permission, 8741da177e4SLinus Torvalds .setattr = hostfs_setattr, 8751da177e4SLinus Torvalds }; 8761da177e4SLinus Torvalds 87792e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8781da177e4SLinus Torvalds .create = hostfs_create, 8791da177e4SLinus Torvalds .lookup = hostfs_lookup, 8801da177e4SLinus Torvalds .link = hostfs_link, 8811da177e4SLinus Torvalds .unlink = hostfs_unlink, 8821da177e4SLinus Torvalds .symlink = hostfs_symlink, 8831da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8841da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8851da177e4SLinus Torvalds .mknod = hostfs_mknod, 8861da177e4SLinus Torvalds .rename = hostfs_rename, 8871da177e4SLinus Torvalds .permission = hostfs_permission, 8881da177e4SLinus Torvalds .setattr = hostfs_setattr, 8891da177e4SLinus Torvalds }; 8901da177e4SLinus Torvalds 8911da177e4SLinus Torvalds int hostfs_link_readpage(struct file *file, struct page *page) 8921da177e4SLinus Torvalds { 8931da177e4SLinus Torvalds char *buffer, *name; 8941da177e4SLinus Torvalds int err; 8951da177e4SLinus Torvalds 8961da177e4SLinus Torvalds buffer = kmap(page); 8971da177e4SLinus Torvalds name = inode_name(page->mapping->host, 0); 898f1adc05eSJeff Dike if (name == NULL) 899f1adc05eSJeff Dike return -ENOMEM; 900ea7e743eSWANG Cong err = hostfs_do_readlink(name, buffer, PAGE_CACHE_SIZE); 9011da177e4SLinus Torvalds kfree(name); 9021da177e4SLinus Torvalds if (err == PAGE_CACHE_SIZE) 9031da177e4SLinus Torvalds err = -E2BIG; 9041da177e4SLinus Torvalds else if (err > 0) { 9051da177e4SLinus Torvalds flush_dcache_page(page); 9061da177e4SLinus Torvalds SetPageUptodate(page); 9071da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 9081da177e4SLinus Torvalds err = 0; 9091da177e4SLinus Torvalds } 9101da177e4SLinus Torvalds kunmap(page); 9111da177e4SLinus Torvalds unlock_page(page); 912f1adc05eSJeff Dike return err; 9131da177e4SLinus Torvalds } 9141da177e4SLinus Torvalds 915f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_link_aops = { 9161da177e4SLinus Torvalds .readpage = hostfs_link_readpage, 9171da177e4SLinus Torvalds }; 9181da177e4SLinus Torvalds 9191da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9201da177e4SLinus Torvalds { 9211da177e4SLinus Torvalds struct inode *root_inode; 92275e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9231da177e4SLinus Torvalds int err; 9241da177e4SLinus Torvalds 9251da177e4SLinus Torvalds sb->s_blocksize = 1024; 9261da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9271da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9281da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 929752fa51eSWolfgang Illmeyer sb->s_maxbytes = MAX_LFS_FILESIZE; 9301da177e4SLinus Torvalds 931a6eb0be6SPaolo 'Blaisorblade' Giarrusso /* NULL is printed as <NULL> by sprintf: avoid that. */ 93275e8defbSPaolo 'Blaisorblade' Giarrusso if (req_root == NULL) 93375e8defbSPaolo 'Blaisorblade' Giarrusso req_root = ""; 9341da177e4SLinus Torvalds 9351da177e4SLinus Torvalds err = -ENOMEM; 936601d2c38SAl Viro sb->s_fs_info = host_root_path = 937601d2c38SAl Viro kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); 93875e8defbSPaolo 'Blaisorblade' Giarrusso if (host_root_path == NULL) 9391da177e4SLinus Torvalds goto out; 9401da177e4SLinus Torvalds 94175e8defbSPaolo 'Blaisorblade' Giarrusso sprintf(host_root_path, "%s/%s", root_ino, req_root); 9421da177e4SLinus Torvalds 94352b209f7SAl Viro root_inode = new_inode(sb); 94452b209f7SAl Viro if (!root_inode) 945601d2c38SAl Viro goto out; 9461da177e4SLinus Torvalds 94752b209f7SAl Viro root_inode->i_op = &hostfs_dir_iops; 94852b209f7SAl Viro root_inode->i_fop = &hostfs_dir_fops; 94952b209f7SAl Viro 95052b209f7SAl Viro if (file_type(host_root_path, NULL, NULL) == OS_TYPE_SYMLINK) { 95152b209f7SAl Viro char *name = follow_link(host_root_path); 95252b209f7SAl Viro if (IS_ERR(name)) 95352b209f7SAl Viro err = PTR_ERR(name); 95452b209f7SAl Viro else 95552b209f7SAl Viro err = read_name(root_inode, name); 95652b209f7SAl Viro kfree(name); 95752b209f7SAl Viro } else { 95852b209f7SAl Viro err = read_name(root_inode, host_root_path); 95952b209f7SAl Viro } 9601da177e4SLinus Torvalds if (err) 9611da177e4SLinus Torvalds goto out_put; 9621da177e4SLinus Torvalds 9631da177e4SLinus Torvalds err = -ENOMEM; 9641da177e4SLinus Torvalds sb->s_root = d_alloc_root(root_inode); 9651da177e4SLinus Torvalds if (sb->s_root == NULL) 9661da177e4SLinus Torvalds goto out_put; 9671da177e4SLinus Torvalds 968f1adc05eSJeff Dike return 0; 9691da177e4SLinus Torvalds 9701da177e4SLinus Torvalds out_put: 9711da177e4SLinus Torvalds iput(root_inode); 9721da177e4SLinus Torvalds out: 973f1adc05eSJeff Dike return err; 9741da177e4SLinus Torvalds } 9751da177e4SLinus Torvalds 976454e2398SDavid Howells static int hostfs_read_sb(struct file_system_type *type, 9771da177e4SLinus Torvalds int flags, const char *dev_name, 978454e2398SDavid Howells void *data, struct vfsmount *mnt) 9791da177e4SLinus Torvalds { 980454e2398SDavid Howells return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); 9811da177e4SLinus Torvalds } 9821da177e4SLinus Torvalds 983601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s) 984601d2c38SAl Viro { 985601d2c38SAl Viro kill_anon_super(s); 986601d2c38SAl Viro kfree(s->s_fs_info); 987601d2c38SAl Viro } 988601d2c38SAl Viro 9891da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 9901da177e4SLinus Torvalds .owner = THIS_MODULE, 9911da177e4SLinus Torvalds .name = "hostfs", 9921da177e4SLinus Torvalds .get_sb = hostfs_read_sb, 993601d2c38SAl Viro .kill_sb = hostfs_kill_sb, 9941da177e4SLinus Torvalds .fs_flags = 0, 9951da177e4SLinus Torvalds }; 9961da177e4SLinus Torvalds 9971da177e4SLinus Torvalds static int __init init_hostfs(void) 9981da177e4SLinus Torvalds { 999f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 10001da177e4SLinus Torvalds } 10011da177e4SLinus Torvalds 10021da177e4SLinus Torvalds static void __exit exit_hostfs(void) 10031da177e4SLinus Torvalds { 10041da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 10051da177e4SLinus Torvalds } 10061da177e4SLinus Torvalds 10071da177e4SLinus Torvalds module_init(init_hostfs) 10081da177e4SLinus Torvalds module_exit(exit_hostfs) 10091da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1010