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> 102b3b9bb0SJames Hogan #include <linux/magic.h> 111da177e4SLinus Torvalds #include <linux/module.h> 1284b3db04SJeff Dike #include <linux/mm.h> 131da177e4SLinus Torvalds #include <linux/pagemap.h> 141da177e4SLinus Torvalds #include <linux/statfs.h> 155a0e3ad6STejun Heo #include <linux/slab.h> 16dd2cc4dfSMiklos Szeredi #include <linux/seq_file.h> 176966a977SJiri Kosina #include <linux/mount.h> 18d0352d3eSAl Viro #include <linux/namei.h> 191da177e4SLinus Torvalds #include "hostfs.h" 2037185b33SAl Viro #include <init.h> 2137185b33SAl Viro #include <kern.h> 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds struct hostfs_inode_info { 241da177e4SLinus Torvalds int fd; 25aeb5d727SAl Viro fmode_t mode; 261da177e4SLinus Torvalds struct inode vfs_inode; 2769886e67SRichard Weinberger struct mutex open_mutex; 281da177e4SLinus Torvalds }; 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 311da177e4SLinus Torvalds { 32f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode); 331da177e4SLinus Torvalds } 341da177e4SLinus Torvalds 35496ad9aaSAl Viro #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file)) 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 38a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 391da177e4SLinus Torvalds static int append = 0; 401da177e4SLinus Torvalds 4192e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 4292e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 43d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops; 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds #ifndef MODULE 461da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 471da177e4SLinus Torvalds { 481da177e4SLinus Torvalds char *ptr; 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds ptr = strchr(options, ','); 511da177e4SLinus Torvalds if (ptr != NULL) 521da177e4SLinus Torvalds *ptr++ = '\0'; 531da177e4SLinus Torvalds if (*options != '\0') 541da177e4SLinus Torvalds root_ino = options; 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds options = ptr; 571da177e4SLinus Torvalds while (options) { 581da177e4SLinus Torvalds ptr = strchr(options, ','); 591da177e4SLinus Torvalds if (ptr != NULL) 601da177e4SLinus Torvalds *ptr++ = '\0'; 611da177e4SLinus Torvalds if (*options != '\0') { 621da177e4SLinus Torvalds if (!strcmp(options, "append")) 631da177e4SLinus Torvalds append = 1; 641da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 651da177e4SLinus Torvalds options); 661da177e4SLinus Torvalds } 671da177e4SLinus Torvalds options = ptr; 681da177e4SLinus Torvalds } 69f1adc05eSJeff Dike return 0; 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 731da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 741da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 751da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 761da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 771da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 781da177e4SLinus Torvalds " it.\n" 791da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 801da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 811da177e4SLinus Torvalds ); 821da177e4SLinus Torvalds #endif 831da177e4SLinus Torvalds 84e9193059SAl Viro static char *__dentry_name(struct dentry *dentry, char *name) 85e9193059SAl Viro { 86ec2447c2SNick Piggin char *p = dentry_path_raw(dentry, name, PATH_MAX); 87e9193059SAl Viro char *root; 88e9193059SAl Viro size_t len; 89e9193059SAl Viro 90e9193059SAl Viro root = dentry->d_sb->s_fs_info; 91e9193059SAl Viro len = strlen(root); 92e9193059SAl Viro if (IS_ERR(p)) { 93e9193059SAl Viro __putname(name); 94e9193059SAl Viro return NULL; 95e9193059SAl Viro } 96aad50b1eSRichard Weinberger 97aad50b1eSRichard Weinberger /* 98aad50b1eSRichard Weinberger * This function relies on the fact that dentry_path_raw() will place 99aad50b1eSRichard Weinberger * the path name at the end of the provided buffer. 100aad50b1eSRichard Weinberger */ 101aad50b1eSRichard Weinberger BUG_ON(p + strlen(p) + 1 != name + PATH_MAX); 102aad50b1eSRichard Weinberger 103850a496fSAl Viro strlcpy(name, root, PATH_MAX); 104e9193059SAl Viro if (len > p - name) { 105e9193059SAl Viro __putname(name); 106e9193059SAl Viro return NULL; 107e9193059SAl Viro } 108c278e81bSRichard Weinberger 109c278e81bSRichard Weinberger if (p > name + len) 110c278e81bSRichard Weinberger strcpy(name + len, p); 111c278e81bSRichard Weinberger 112e9193059SAl Viro return name; 113e9193059SAl Viro } 114e9193059SAl Viro 115c5322220SAl Viro static char *dentry_name(struct dentry *dentry) 1161da177e4SLinus Torvalds { 117e9193059SAl Viro char *name = __getname(); 118e9193059SAl Viro if (!name) 119f1adc05eSJeff Dike return NULL; 1201da177e4SLinus Torvalds 1219dcc5e8aSJames Hogan return __dentry_name(dentry, name); 1221da177e4SLinus Torvalds } 1231da177e4SLinus Torvalds 124c5322220SAl Viro static char *inode_name(struct inode *ino) 1251da177e4SLinus Torvalds { 1261da177e4SLinus Torvalds struct dentry *dentry; 127ec2447c2SNick Piggin char *name; 128ec2447c2SNick Piggin 129ec2447c2SNick Piggin dentry = d_find_alias(ino); 130ec2447c2SNick Piggin if (!dentry) 131e9193059SAl Viro return NULL; 1321da177e4SLinus Torvalds 133ec2447c2SNick Piggin name = dentry_name(dentry); 134ec2447c2SNick Piggin 135ec2447c2SNick Piggin dput(dentry); 136ec2447c2SNick Piggin 137ec2447c2SNick Piggin return name; 1381da177e4SLinus Torvalds } 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds static char *follow_link(char *link) 1411da177e4SLinus Torvalds { 1421da177e4SLinus Torvalds char *name, *resolved, *end; 143b58c4e96SAndy Shevchenko int n; 1441da177e4SLinus Torvalds 1457c950992SRichard Weinberger name = __getname(); 1467c950992SRichard Weinberger if (!name) { 1471da177e4SLinus Torvalds n = -ENOMEM; 1487c950992SRichard Weinberger goto out_free; 1491da177e4SLinus Torvalds } 1507c950992SRichard Weinberger 1517c950992SRichard Weinberger n = hostfs_do_readlink(link, name, PATH_MAX); 1521da177e4SLinus Torvalds if (n < 0) 1531da177e4SLinus Torvalds goto out_free; 1547c950992SRichard Weinberger else if (n == PATH_MAX) { 1557c950992SRichard Weinberger n = -E2BIG; 1567c950992SRichard Weinberger goto out_free; 1577c950992SRichard Weinberger } 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds if (*name == '/') 160f1adc05eSJeff Dike return name; 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds end = strrchr(link, '/'); 1631da177e4SLinus Torvalds if (end == NULL) 164f1adc05eSJeff Dike return name; 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds *(end + 1) = '\0'; 1671da177e4SLinus Torvalds 168b58c4e96SAndy Shevchenko resolved = kasprintf(GFP_KERNEL, "%s%s", link, name); 1691da177e4SLinus Torvalds if (resolved == NULL) { 1701da177e4SLinus Torvalds n = -ENOMEM; 1711da177e4SLinus Torvalds goto out_free; 1721da177e4SLinus Torvalds } 1731da177e4SLinus Torvalds 1747c950992SRichard Weinberger __putname(name); 1751da177e4SLinus Torvalds kfree(link); 176f1adc05eSJeff Dike return resolved; 1771da177e4SLinus Torvalds 1781da177e4SLinus Torvalds out_free: 1797c950992SRichard Weinberger __putname(name); 180f1adc05eSJeff Dike return ERR_PTR(n); 1811da177e4SLinus Torvalds } 1821da177e4SLinus Torvalds 1830a370e5dSDavid Howells static struct inode *hostfs_iget(struct super_block *sb) 1840a370e5dSDavid Howells { 18552b209f7SAl Viro struct inode *inode = new_inode(sb); 1860a370e5dSDavid Howells if (!inode) 1870a370e5dSDavid Howells return ERR_PTR(-ENOMEM); 1880a370e5dSDavid Howells return inode; 1890a370e5dSDavid Howells } 1900a370e5dSDavid Howells 1919e443bc3SJames Hogan static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 1921da177e4SLinus Torvalds { 19384b3db04SJeff Dike /* 19484b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 1951da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 1961da177e4SLinus Torvalds * so we convert them here 1971da177e4SLinus Torvalds */ 1981da177e4SLinus Torvalds int err; 1991da177e4SLinus Torvalds long long f_blocks; 2001da177e4SLinus Torvalds long long f_bfree; 2011da177e4SLinus Torvalds long long f_bavail; 2021da177e4SLinus Torvalds long long f_files; 2031da177e4SLinus Torvalds long long f_ffree; 2041da177e4SLinus Torvalds 205601d2c38SAl Viro err = do_statfs(dentry->d_sb->s_fs_info, 2061da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2071da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2081b627d57SRichard Weinberger &sf->f_namelen); 209f1adc05eSJeff Dike if (err) 210f1adc05eSJeff Dike return err; 2111da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2121da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2131da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2141da177e4SLinus Torvalds sf->f_files = f_files; 2151da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2161da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 217f1adc05eSJeff Dike return 0; 2181da177e4SLinus Torvalds } 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2211da177e4SLinus Torvalds { 2221da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2231da177e4SLinus Torvalds 2245d097056SVladimir Davydov hi = kmalloc(sizeof(*hi), GFP_KERNEL_ACCOUNT); 2251da177e4SLinus Torvalds if (hi == NULL) 226f1adc05eSJeff Dike return NULL; 227601d2c38SAl Viro hi->fd = -1; 228371fdab1SJames Hogan hi->mode = 0; 2291da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 23069886e67SRichard Weinberger mutex_init(&hi->open_mutex); 231f1adc05eSJeff Dike return &hi->vfs_inode; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds 234e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode) 2351da177e4SLinus Torvalds { 23691b0abe3SJohannes Weiner truncate_inode_pages_final(&inode->i_data); 237dbd5768fSJan Kara clear_inode(inode); 2381da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2391da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2401da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2411da177e4SLinus Torvalds } 2421da177e4SLinus Torvalds } 2431da177e4SLinus Torvalds 24408ccfc5cSAl Viro static void hostfs_free_inode(struct inode *inode) 245fa0d7e3dSNick Piggin { 246fa0d7e3dSNick Piggin kfree(HOSTFS_I(inode)); 247fa0d7e3dSNick Piggin } 248fa0d7e3dSNick Piggin 24934c80b1dSAl Viro static int hostfs_show_options(struct seq_file *seq, struct dentry *root) 250dd2cc4dfSMiklos Szeredi { 25134c80b1dSAl Viro const char *root_path = root->d_sb->s_fs_info; 252dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1; 253dd2cc4dfSMiklos Szeredi 254dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset) 255a068acf2SKees Cook seq_show_option(seq, root_path + offset, NULL); 256dd2cc4dfSMiklos Szeredi 2577f74a668SRichard Weinberger if (append) 2587f74a668SRichard Weinberger seq_puts(seq, ",append"); 2597f74a668SRichard Weinberger 260dd2cc4dfSMiklos Szeredi return 0; 261dd2cc4dfSMiklos Szeredi } 262dd2cc4dfSMiklos Szeredi 263ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 2641da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 26508ccfc5cSAl Viro .free_inode = hostfs_free_inode, 266e971a6d7SAl Viro .evict_inode = hostfs_evict_inode, 2671da177e4SLinus Torvalds .statfs = hostfs_statfs, 268dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options, 2691da177e4SLinus Torvalds }; 2701da177e4SLinus Torvalds 2719e443bc3SJames Hogan static int hostfs_readdir(struct file *file, struct dir_context *ctx) 2721da177e4SLinus Torvalds { 2731da177e4SLinus Torvalds void *dir; 2741da177e4SLinus Torvalds char *name; 2751da177e4SLinus Torvalds unsigned long long next, ino; 2761da177e4SLinus Torvalds int error, len; 2773ee6bd8eSGeert Uytterhoeven unsigned int type; 2781da177e4SLinus Torvalds 279c5322220SAl Viro name = dentry_name(file->f_path.dentry); 280f1adc05eSJeff Dike if (name == NULL) 281f1adc05eSJeff Dike return -ENOMEM; 2821da177e4SLinus Torvalds dir = open_dir(name, &error); 283e9193059SAl Viro __putname(name); 284f1adc05eSJeff Dike if (dir == NULL) 285f1adc05eSJeff Dike return -error; 2868e28bc7eSAl Viro next = ctx->pos; 2870c9bd636SRichard Weinberger seek_dir(dir, next); 2883ee6bd8eSGeert Uytterhoeven while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { 2898e28bc7eSAl Viro if (!dir_emit(ctx, name, len, ino, type)) 2908e28bc7eSAl Viro break; 2918e28bc7eSAl Viro ctx->pos = next; 2921da177e4SLinus Torvalds } 2931da177e4SLinus Torvalds close_dir(dir); 294f1adc05eSJeff Dike return 0; 2951da177e4SLinus Torvalds } 2961da177e4SLinus Torvalds 2974c6dcafcSRichard Weinberger static int hostfs_open(struct inode *ino, struct file *file) 2981da177e4SLinus Torvalds { 2991da177e4SLinus Torvalds char *name; 300bd1052a2SRichard Weinberger fmode_t mode; 301f8ad850fSAl Viro int err; 302bd1052a2SRichard Weinberger int r, w, fd; 3031da177e4SLinus Torvalds 3041da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3051da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode) 306f1adc05eSJeff Dike return 0; 3071da177e4SLinus Torvalds 308f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 3091da177e4SLinus Torvalds 310f8ad850fSAl Viro retry: 311a9d1958bSRichard Weinberger r = w = 0; 312a9d1958bSRichard Weinberger 313f8ad850fSAl Viro if (mode & FMODE_READ) 3141da177e4SLinus Torvalds r = 1; 315f8ad850fSAl Viro if (mode & FMODE_WRITE) 316112a5da7SRichard Weinberger r = w = 1; 3171da177e4SLinus Torvalds 3182e2cbaf9SAl Viro name = dentry_name(d_real(file->f_path.dentry, file->f_inode)); 3191da177e4SLinus Torvalds if (name == NULL) 320f1adc05eSJeff Dike return -ENOMEM; 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds fd = open_file(name, r, w, append); 323e9193059SAl Viro __putname(name); 324f1adc05eSJeff Dike if (fd < 0) 325f1adc05eSJeff Dike return fd; 326f8ad850fSAl Viro 32769886e67SRichard Weinberger mutex_lock(&HOSTFS_I(ino)->open_mutex); 328f8ad850fSAl Viro /* somebody else had handled it first? */ 329f8ad850fSAl Viro if ((mode & HOSTFS_I(ino)->mode) == mode) { 33069886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 331af955658SRichard Weinberger close_file(&fd); 332f8ad850fSAl Viro return 0; 333f8ad850fSAl Viro } 334f8ad850fSAl Viro if ((mode | HOSTFS_I(ino)->mode) != mode) { 335f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 33669886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 337f8ad850fSAl Viro close_file(&fd); 338f8ad850fSAl Viro goto retry; 339f8ad850fSAl Viro } 340f8ad850fSAl Viro if (HOSTFS_I(ino)->fd == -1) { 341f8ad850fSAl Viro HOSTFS_I(ino)->fd = fd; 342f8ad850fSAl Viro } else { 343f8ad850fSAl Viro err = replace_file(fd, HOSTFS_I(ino)->fd); 344f8ad850fSAl Viro close_file(&fd); 345f8ad850fSAl Viro if (err < 0) { 34669886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 347f8ad850fSAl Viro return err; 348f8ad850fSAl Viro } 349f8ad850fSAl Viro } 350f8ad850fSAl Viro HOSTFS_I(ino)->mode = mode; 35169886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 3521da177e4SLinus Torvalds 353f1adc05eSJeff Dike return 0; 3541da177e4SLinus Torvalds } 3551da177e4SLinus Torvalds 35665984ff9SRichard Weinberger static int hostfs_file_release(struct inode *inode, struct file *file) 35765984ff9SRichard Weinberger { 35865984ff9SRichard Weinberger filemap_write_and_wait(inode->i_mapping); 35965984ff9SRichard Weinberger 36065984ff9SRichard Weinberger return 0; 36165984ff9SRichard Weinberger } 36265984ff9SRichard Weinberger 3639e443bc3SJames Hogan static int hostfs_fsync(struct file *file, loff_t start, loff_t end, 3649e443bc3SJames Hogan int datasync) 3651da177e4SLinus Torvalds { 36602c24a82SJosef Bacik struct inode *inode = file->f_mapping->host; 36702c24a82SJosef Bacik int ret; 36802c24a82SJosef Bacik 3693b49c9a1SJeff Layton ret = file_write_and_wait_range(file, start, end); 37002c24a82SJosef Bacik if (ret) 37102c24a82SJosef Bacik return ret; 37202c24a82SJosef Bacik 3735955102cSAl Viro inode_lock(inode); 37402c24a82SJosef Bacik ret = fsync_file(HOSTFS_I(inode)->fd, datasync); 3755955102cSAl Viro inode_unlock(inode); 37602c24a82SJosef Bacik 37702c24a82SJosef Bacik return ret; 3781da177e4SLinus Torvalds } 3791da177e4SLinus Torvalds 3804b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3811da177e4SLinus Torvalds .llseek = generic_file_llseek, 3825ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 383aad4f8bbSAl Viro .read_iter = generic_file_read_iter, 3848174202bSAl Viro .write_iter = generic_file_write_iter, 3851da177e4SLinus Torvalds .mmap = generic_file_mmap, 3864c6dcafcSRichard Weinberger .open = hostfs_open, 38765984ff9SRichard Weinberger .release = hostfs_file_release, 3881da177e4SLinus Torvalds .fsync = hostfs_fsync, 3891da177e4SLinus Torvalds }; 3901da177e4SLinus Torvalds 3914b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 3921da177e4SLinus Torvalds .llseek = generic_file_llseek, 393552a9d48SAl Viro .iterate_shared = hostfs_readdir, 3941da177e4SLinus Torvalds .read = generic_read_dir, 3954c6dcafcSRichard Weinberger .open = hostfs_open, 3964c6dcafcSRichard Weinberger .fsync = hostfs_fsync, 3971da177e4SLinus Torvalds }; 3981da177e4SLinus Torvalds 3999e443bc3SJames Hogan static int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4001da177e4SLinus Torvalds { 4011da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4021da177e4SLinus Torvalds struct inode *inode = mapping->host; 4031da177e4SLinus Torvalds char *buffer; 404af6aa1b9SRichard Weinberger loff_t base = page_offset(page); 40509cbfeafSKirill A. Shutemov int count = PAGE_SIZE; 40609cbfeafSKirill A. Shutemov int end_index = inode->i_size >> PAGE_SHIFT; 4071da177e4SLinus Torvalds int err; 4081da177e4SLinus Torvalds 4091da177e4SLinus Torvalds if (page->index >= end_index) 41009cbfeafSKirill A. Shutemov count = inode->i_size & (PAGE_SIZE-1); 4111da177e4SLinus Torvalds 4121da177e4SLinus Torvalds buffer = kmap(page); 4131da177e4SLinus Torvalds 4141da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4151da177e4SLinus Torvalds if (err != count) { 4161da177e4SLinus Torvalds ClearPageUptodate(page); 4171da177e4SLinus Torvalds goto out; 4181da177e4SLinus Torvalds } 4191da177e4SLinus Torvalds 4201da177e4SLinus Torvalds if (base > inode->i_size) 4211da177e4SLinus Torvalds inode->i_size = base; 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds if (PageError(page)) 4241da177e4SLinus Torvalds ClearPageError(page); 4251da177e4SLinus Torvalds err = 0; 4261da177e4SLinus Torvalds 4271da177e4SLinus Torvalds out: 4281da177e4SLinus Torvalds kunmap(page); 4291da177e4SLinus Torvalds 4301da177e4SLinus Torvalds unlock_page(page); 4311da177e4SLinus Torvalds return err; 4321da177e4SLinus Torvalds } 4331da177e4SLinus Torvalds 4349e443bc3SJames Hogan static int hostfs_readpage(struct file *file, struct page *page) 4351da177e4SLinus Torvalds { 4361da177e4SLinus Torvalds char *buffer; 437af6aa1b9SRichard Weinberger loff_t start = page_offset(page); 438b86b413aSRichard Weinberger int bytes_read, ret = 0; 4391da177e4SLinus Torvalds 4401da177e4SLinus Torvalds buffer = kmap(page); 44141761ddfSRichard Weinberger bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 44209cbfeafSKirill A. Shutemov PAGE_SIZE); 44341761ddfSRichard Weinberger if (bytes_read < 0) { 444b86b413aSRichard Weinberger ClearPageUptodate(page); 445b86b413aSRichard Weinberger SetPageError(page); 44641761ddfSRichard Weinberger ret = bytes_read; 44784b3db04SJeff Dike goto out; 44841761ddfSRichard Weinberger } 4491da177e4SLinus Torvalds 45009cbfeafSKirill A. Shutemov memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read); 4511da177e4SLinus Torvalds 452b86b413aSRichard Weinberger ClearPageError(page); 4531da177e4SLinus Torvalds SetPageUptodate(page); 454b86b413aSRichard Weinberger 4551da177e4SLinus Torvalds out: 456b86b413aSRichard Weinberger flush_dcache_page(page); 4571da177e4SLinus Torvalds kunmap(page); 4581da177e4SLinus Torvalds unlock_page(page); 45941761ddfSRichard Weinberger return ret; 4601da177e4SLinus Torvalds } 4611da177e4SLinus Torvalds 4629e443bc3SJames Hogan static int hostfs_write_begin(struct file *file, struct address_space *mapping, 463ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 464ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4651da177e4SLinus Torvalds { 46609cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT; 467ae361ff4SNick Piggin 46854566b2cSNick Piggin *pagep = grab_cache_page_write_begin(mapping, index, flags); 469ae361ff4SNick Piggin if (!*pagep) 470ae361ff4SNick Piggin return -ENOMEM; 471ae361ff4SNick Piggin return 0; 472ae361ff4SNick Piggin } 473ae361ff4SNick Piggin 4749e443bc3SJames Hogan static int hostfs_write_end(struct file *file, struct address_space *mapping, 475ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 476ae361ff4SNick Piggin struct page *page, void *fsdata) 477ae361ff4SNick Piggin { 478ae361ff4SNick Piggin struct inode *inode = mapping->host; 479ae361ff4SNick Piggin void *buffer; 48009cbfeafSKirill A. Shutemov unsigned from = pos & (PAGE_SIZE - 1); 4811da177e4SLinus Torvalds int err; 4821da177e4SLinus Torvalds 4831da177e4SLinus Torvalds buffer = kmap(page); 484ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4851da177e4SLinus Torvalds kunmap(page); 4861da177e4SLinus Torvalds 48709cbfeafSKirill A. Shutemov if (!PageUptodate(page) && err == PAGE_SIZE) 488ae361ff4SNick Piggin SetPageUptodate(page); 4891da177e4SLinus Torvalds 49084b3db04SJeff Dike /* 49184b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 492ae361ff4SNick Piggin * i_size against the last byte written. 493ae361ff4SNick Piggin */ 494ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 495ae361ff4SNick Piggin inode->i_size = pos; 496ae361ff4SNick Piggin unlock_page(page); 49709cbfeafSKirill A. Shutemov put_page(page); 49830f04a4eSPaolo 'Blaisorblade' Giarrusso 499f1adc05eSJeff Dike return err; 5001da177e4SLinus Torvalds } 5011da177e4SLinus Torvalds 502f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 5031da177e4SLinus Torvalds .writepage = hostfs_writepage, 5041da177e4SLinus Torvalds .readpage = hostfs_readpage, 505ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 506ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 507ae361ff4SNick Piggin .write_end = hostfs_write_end, 5081da177e4SLinus Torvalds }; 5091da177e4SLinus Torvalds 5104754b825SAl Viro static int read_name(struct inode *ino, char *name) 5111da177e4SLinus Torvalds { 5124754b825SAl Viro dev_t rdev; 5134754b825SAl Viro struct hostfs_stat st; 5144754b825SAl Viro int err = stat_file(name, &st, -1); 5154754b825SAl Viro if (err) 5164754b825SAl Viro return err; 5171da177e4SLinus Torvalds 5181da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5194754b825SAl Viro rdev = MKDEV(st.maj, st.min); 5201da177e4SLinus Torvalds 5214754b825SAl Viro switch (st.mode & S_IFMT) { 5224754b825SAl Viro case S_IFLNK: 523d0352d3eSAl Viro ino->i_op = &hostfs_link_iops; 5244754b825SAl Viro break; 5254754b825SAl Viro case S_IFDIR: 5264754b825SAl Viro ino->i_op = &hostfs_dir_iops; 5274754b825SAl Viro ino->i_fop = &hostfs_dir_fops; 5284754b825SAl Viro break; 5294754b825SAl Viro case S_IFCHR: 5304754b825SAl Viro case S_IFBLK: 5314754b825SAl Viro case S_IFIFO: 5324754b825SAl Viro case S_IFSOCK: 5334754b825SAl Viro init_special_inode(ino, st.mode & S_IFMT, rdev); 5344754b825SAl Viro ino->i_op = &hostfs_iops; 5354754b825SAl Viro break; 5362ad2dca6SRichard Weinberger case S_IFREG: 5374754b825SAl Viro ino->i_op = &hostfs_iops; 5384754b825SAl Viro ino->i_fop = &hostfs_file_fops; 5394754b825SAl Viro ino->i_mapping->a_ops = &hostfs_aops; 5402ad2dca6SRichard Weinberger break; 5412ad2dca6SRichard Weinberger default: 5422ad2dca6SRichard Weinberger return -EIO; 5431da177e4SLinus Torvalds } 5444754b825SAl Viro 5454754b825SAl Viro ino->i_ino = st.ino; 5464754b825SAl Viro ino->i_mode = st.mode; 547bfe86848SMiklos Szeredi set_nlink(ino, st.nlink); 54829f82ae5SEric W. Biederman i_uid_write(ino, st.uid); 54929f82ae5SEric W. Biederman i_gid_write(ino, st.gid); 550bca30265SArnd Bergmann ino->i_atime = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec }; 551bca30265SArnd Bergmann ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec }; 552bca30265SArnd Bergmann ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec }; 5534754b825SAl Viro ino->i_size = st.size; 5544754b825SAl Viro ino->i_blocks = st.blocks; 5554754b825SAl Viro return 0; 5561da177e4SLinus Torvalds } 5571da177e4SLinus Torvalds 558*549c7297SChristian Brauner static int hostfs_create(struct user_namespace *mnt_userns, struct inode *dir, 559*549c7297SChristian Brauner struct dentry *dentry, umode_t mode, bool excl) 5601da177e4SLinus Torvalds { 5611da177e4SLinus Torvalds struct inode *inode; 5621da177e4SLinus Torvalds char *name; 5631da177e4SLinus Torvalds int error, fd; 5641da177e4SLinus Torvalds 5650a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 5660a370e5dSDavid Howells if (IS_ERR(inode)) { 5670a370e5dSDavid Howells error = PTR_ERR(inode); 56884b3db04SJeff Dike goto out; 5690a370e5dSDavid Howells } 5701da177e4SLinus Torvalds 5711da177e4SLinus Torvalds error = -ENOMEM; 572c5322220SAl Viro name = dentry_name(dentry); 5731da177e4SLinus Torvalds if (name == NULL) 5741da177e4SLinus Torvalds goto out_put; 5751da177e4SLinus Torvalds 576a718c922SRichard Weinberger fd = file_create(name, mode & 0777); 5774754b825SAl Viro if (fd < 0) 5781da177e4SLinus Torvalds error = fd; 5794754b825SAl Viro else 5805e2df28cSAl Viro error = read_name(inode, name); 5811da177e4SLinus Torvalds 582e9193059SAl Viro __putname(name); 5831da177e4SLinus Torvalds if (error) 5841da177e4SLinus Torvalds goto out_put; 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5871da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 5881da177e4SLinus Torvalds d_instantiate(dentry, inode); 589f1adc05eSJeff Dike return 0; 5901da177e4SLinus Torvalds 5911da177e4SLinus Torvalds out_put: 5921da177e4SLinus Torvalds iput(inode); 5931da177e4SLinus Torvalds out: 594f1adc05eSJeff Dike return error; 5951da177e4SLinus Torvalds } 5961da177e4SLinus Torvalds 5979e443bc3SJames Hogan static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 59800cd8dd3SAl Viro unsigned int flags) 5991da177e4SLinus Torvalds { 6001da177e4SLinus Torvalds struct inode *inode; 6011da177e4SLinus Torvalds char *name; 6021da177e4SLinus Torvalds int err; 6031da177e4SLinus Torvalds 6040a370e5dSDavid Howells inode = hostfs_iget(ino->i_sb); 60550f30740SAl Viro if (IS_ERR(inode)) 6061da177e4SLinus Torvalds goto out; 6071da177e4SLinus Torvalds 6081da177e4SLinus Torvalds err = -ENOMEM; 609c5322220SAl Viro name = dentry_name(dentry); 61050f30740SAl Viro if (name) { 6111da177e4SLinus Torvalds err = read_name(inode, name); 612e9193059SAl Viro __putname(name); 6131da177e4SLinus Torvalds } 61450f30740SAl Viro if (err) { 6151da177e4SLinus Torvalds iput(inode); 61650f30740SAl Viro inode = (err == -ENOENT) ? NULL : ERR_PTR(err); 61750f30740SAl Viro } 6181da177e4SLinus Torvalds out: 61950f30740SAl Viro return d_splice_alias(inode, dentry); 6201da177e4SLinus Torvalds } 6211da177e4SLinus Torvalds 6229e443bc3SJames Hogan static int hostfs_link(struct dentry *to, struct inode *ino, 6239e443bc3SJames Hogan struct dentry *from) 6241da177e4SLinus Torvalds { 6251da177e4SLinus Torvalds char *from_name, *to_name; 6261da177e4SLinus Torvalds int err; 6271da177e4SLinus Torvalds 628c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 629f1adc05eSJeff Dike return -ENOMEM; 630c5322220SAl Viro to_name = dentry_name(to); 6311da177e4SLinus Torvalds if (to_name == NULL) { 632e9193059SAl Viro __putname(from_name); 633f1adc05eSJeff Dike return -ENOMEM; 6341da177e4SLinus Torvalds } 6351da177e4SLinus Torvalds err = link_file(to_name, from_name); 636e9193059SAl Viro __putname(from_name); 637e9193059SAl Viro __putname(to_name); 638f1adc05eSJeff Dike return err; 6391da177e4SLinus Torvalds } 6401da177e4SLinus Torvalds 6419e443bc3SJames Hogan static int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6421da177e4SLinus Torvalds { 6431da177e4SLinus Torvalds char *file; 6441da177e4SLinus Torvalds int err; 6451da177e4SLinus Torvalds 6461da177e4SLinus Torvalds if (append) 647f1adc05eSJeff Dike return -EPERM; 6481da177e4SLinus Torvalds 649f8d7e187SAl Viro if ((file = dentry_name(dentry)) == NULL) 650f8d7e187SAl Viro return -ENOMEM; 651f8d7e187SAl Viro 6521da177e4SLinus Torvalds err = unlink_file(file); 653e9193059SAl Viro __putname(file); 654f1adc05eSJeff Dike return err; 6551da177e4SLinus Torvalds } 6561da177e4SLinus Torvalds 657*549c7297SChristian Brauner static int hostfs_symlink(struct user_namespace *mnt_userns, struct inode *ino, 658*549c7297SChristian Brauner struct dentry *dentry, const char *to) 6591da177e4SLinus Torvalds { 6601da177e4SLinus Torvalds char *file; 6611da177e4SLinus Torvalds int err; 6621da177e4SLinus Torvalds 663c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 664f1adc05eSJeff Dike return -ENOMEM; 6651da177e4SLinus Torvalds err = make_symlink(file, to); 666e9193059SAl Viro __putname(file); 667f1adc05eSJeff Dike return err; 6681da177e4SLinus Torvalds } 6691da177e4SLinus Torvalds 670*549c7297SChristian Brauner static int hostfs_mkdir(struct user_namespace *mnt_userns, struct inode *ino, 671*549c7297SChristian Brauner struct dentry *dentry, umode_t mode) 6721da177e4SLinus Torvalds { 6731da177e4SLinus Torvalds char *file; 6741da177e4SLinus Torvalds int err; 6751da177e4SLinus Torvalds 676c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 677f1adc05eSJeff Dike return -ENOMEM; 6781da177e4SLinus Torvalds err = do_mkdir(file, mode); 679e9193059SAl Viro __putname(file); 680f1adc05eSJeff Dike return err; 6811da177e4SLinus Torvalds } 6821da177e4SLinus Torvalds 6839e443bc3SJames Hogan static int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 6841da177e4SLinus Torvalds { 6851da177e4SLinus Torvalds char *file; 6861da177e4SLinus Torvalds int err; 6871da177e4SLinus Torvalds 688c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 689f1adc05eSJeff Dike return -ENOMEM; 6906380161cSDominik Brodowski err = hostfs_do_rmdir(file); 691e9193059SAl Viro __putname(file); 692f1adc05eSJeff Dike return err; 6931da177e4SLinus Torvalds } 6941da177e4SLinus Torvalds 695*549c7297SChristian Brauner static int hostfs_mknod(struct user_namespace *mnt_userns, struct inode *dir, 696*549c7297SChristian Brauner struct dentry *dentry, umode_t mode, dev_t dev) 6971da177e4SLinus Torvalds { 6981da177e4SLinus Torvalds struct inode *inode; 6991da177e4SLinus Torvalds char *name; 7000a370e5dSDavid Howells int err; 7011da177e4SLinus Torvalds 7020a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 7030a370e5dSDavid Howells if (IS_ERR(inode)) { 7040a370e5dSDavid Howells err = PTR_ERR(inode); 7051da177e4SLinus Torvalds goto out; 7060a370e5dSDavid Howells } 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds err = -ENOMEM; 709c5322220SAl Viro name = dentry_name(dentry); 7101da177e4SLinus Torvalds if (name == NULL) 7111da177e4SLinus Torvalds goto out_put; 7121da177e4SLinus Torvalds 7131da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 71488f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 7159f2dfda2SVegard Nossum if (err) 7161da177e4SLinus Torvalds goto out_free; 7171da177e4SLinus Torvalds 7181da177e4SLinus Torvalds err = read_name(inode, name); 719e9193059SAl Viro __putname(name); 7205e2df28cSAl Viro if (err) 7215e2df28cSAl Viro goto out_put; 7221da177e4SLinus Torvalds 7231da177e4SLinus Torvalds d_instantiate(dentry, inode); 724f1adc05eSJeff Dike return 0; 7251da177e4SLinus Torvalds 7261da177e4SLinus Torvalds out_free: 727e9193059SAl Viro __putname(name); 7281da177e4SLinus Torvalds out_put: 7291da177e4SLinus Torvalds iput(inode); 7301da177e4SLinus Torvalds out: 731f1adc05eSJeff Dike return err; 7321da177e4SLinus Torvalds } 7331da177e4SLinus Torvalds 734*549c7297SChristian Brauner static int hostfs_rename2(struct user_namespace *mnt_userns, 735*549c7297SChristian Brauner struct inode *old_dir, struct dentry *old_dentry, 7369a423bb6SMiklos Szeredi struct inode *new_dir, struct dentry *new_dentry, 7379a423bb6SMiklos Szeredi unsigned int flags) 7381da177e4SLinus Torvalds { 7399a423bb6SMiklos Szeredi char *old_name, *new_name; 7401da177e4SLinus Torvalds int err; 7411da177e4SLinus Torvalds 7429a423bb6SMiklos Szeredi if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) 7439a423bb6SMiklos Szeredi return -EINVAL; 7449a423bb6SMiklos Szeredi 7459a423bb6SMiklos Szeredi old_name = dentry_name(old_dentry); 7469a423bb6SMiklos Szeredi if (old_name == NULL) 747f1adc05eSJeff Dike return -ENOMEM; 7489a423bb6SMiklos Szeredi new_name = dentry_name(new_dentry); 7499a423bb6SMiklos Szeredi if (new_name == NULL) { 7509a423bb6SMiklos Szeredi __putname(old_name); 751f1adc05eSJeff Dike return -ENOMEM; 7521da177e4SLinus Torvalds } 7539a423bb6SMiklos Szeredi if (!flags) 7549a423bb6SMiklos Szeredi err = rename_file(old_name, new_name); 7559a423bb6SMiklos Szeredi else 7569a423bb6SMiklos Szeredi err = rename2_file(old_name, new_name, flags); 7579a423bb6SMiklos Szeredi 7589a423bb6SMiklos Szeredi __putname(old_name); 7599a423bb6SMiklos Szeredi __putname(new_name); 760f1adc05eSJeff Dike return err; 7611da177e4SLinus Torvalds } 7621da177e4SLinus Torvalds 763*549c7297SChristian Brauner static int hostfs_permission(struct user_namespace *mnt_userns, 764*549c7297SChristian Brauner struct inode *ino, int desired) 7651da177e4SLinus Torvalds { 7661da177e4SLinus Torvalds char *name; 7671da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7681da177e4SLinus Torvalds 76910556cb2SAl Viro if (desired & MAY_NOT_BLOCK) 770b74c79e9SNick Piggin return -ECHILD; 771b74c79e9SNick Piggin 7721da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7731da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7741da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 775c5322220SAl Viro name = inode_name(ino); 776f1adc05eSJeff Dike if (name == NULL) 777f1adc05eSJeff Dike return -ENOMEM; 7781da177e4SLinus Torvalds 7791da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 7801da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 7811da177e4SLinus Torvalds err = 0; 7821da177e4SLinus Torvalds else 7831da177e4SLinus Torvalds err = access_file(name, r, w, x); 784e9193059SAl Viro __putname(name); 7851da177e4SLinus Torvalds if (!err) 78647291baaSChristian Brauner err = generic_permission(&init_user_ns, ino, desired); 7871da177e4SLinus Torvalds return err; 7881da177e4SLinus Torvalds } 7891da177e4SLinus Torvalds 790*549c7297SChristian Brauner static int hostfs_setattr(struct user_namespace *mnt_userns, 791*549c7297SChristian Brauner struct dentry *dentry, struct iattr *attr) 7921da177e4SLinus Torvalds { 7932b0143b5SDavid Howells struct inode *inode = d_inode(dentry); 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 8002f221d6fSChristian Brauner err = setattr_prepare(&init_user_ns, dentry, 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; 81429f82ae5SEric W. Biederman attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); 8151da177e4SLinus Torvalds } 8161da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8171da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 81829f82ae5SEric W. Biederman attrs.ia_gid = from_kgid(&init_user_ns, 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; 826bca30265SArnd Bergmann attrs.ia_atime = (struct hostfs_timespec) 827bca30265SArnd Bergmann { attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec }; 8281da177e4SLinus Torvalds } 8291da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8301da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 831bca30265SArnd Bergmann attrs.ia_mtime = (struct hostfs_timespec) 832bca30265SArnd Bergmann { attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec }; 8331da177e4SLinus Torvalds } 8341da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8351da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 836bca30265SArnd Bergmann attrs.ia_ctime = (struct hostfs_timespec) 837bca30265SArnd Bergmann { attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec }; 8381da177e4SLinus Torvalds } 8391da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) { 8401da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8411da177e4SLinus Torvalds } 8421da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) { 8431da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8441da177e4SLinus Torvalds } 845c5322220SAl Viro name = dentry_name(dentry); 846f1adc05eSJeff Dike if (name == NULL) 847f1adc05eSJeff Dike return -ENOMEM; 8485822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 849e9193059SAl Viro __putname(name); 8501da177e4SLinus Torvalds if (err) 851f1adc05eSJeff Dike return err; 8521da177e4SLinus Torvalds 8531025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 854bc077320SMarco Stornelli attr->ia_size != i_size_read(inode)) 8553be2be0aSMarco Stornelli truncate_setsize(inode, attr->ia_size); 8561025774cSChristoph Hellwig 8572f221d6fSChristian Brauner setattr_copy(&init_user_ns, inode, attr); 8581025774cSChristoph Hellwig mark_inode_dirty(inode); 8591025774cSChristoph Hellwig return 0; 8601da177e4SLinus Torvalds } 8611da177e4SLinus Torvalds 86292e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8631da177e4SLinus Torvalds .permission = hostfs_permission, 8641da177e4SLinus Torvalds .setattr = hostfs_setattr, 8651da177e4SLinus Torvalds }; 8661da177e4SLinus Torvalds 86792e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8681da177e4SLinus Torvalds .create = hostfs_create, 8691da177e4SLinus Torvalds .lookup = hostfs_lookup, 8701da177e4SLinus Torvalds .link = hostfs_link, 8711da177e4SLinus Torvalds .unlink = hostfs_unlink, 8721da177e4SLinus Torvalds .symlink = hostfs_symlink, 8731da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8741da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8751da177e4SLinus Torvalds .mknod = hostfs_mknod, 8762773bf00SMiklos Szeredi .rename = hostfs_rename2, 8771da177e4SLinus Torvalds .permission = hostfs_permission, 8781da177e4SLinus Torvalds .setattr = hostfs_setattr, 8791da177e4SLinus Torvalds }; 8801da177e4SLinus Torvalds 8816b255391SAl Viro static const char *hostfs_get_link(struct dentry *dentry, 882fceef393SAl Viro struct inode *inode, 883fceef393SAl Viro struct delayed_call *done) 8841da177e4SLinus Torvalds { 8856b255391SAl Viro char *link; 8866b255391SAl Viro if (!dentry) 8876b255391SAl Viro return ERR_PTR(-ECHILD); 888fceef393SAl Viro link = kmalloc(PATH_MAX, GFP_KERNEL); 889d0352d3eSAl Viro if (link) { 890d0352d3eSAl Viro char *path = dentry_name(dentry); 891d0352d3eSAl Viro int err = -ENOMEM; 892d0352d3eSAl Viro if (path) { 8933b6036d1SAl Viro err = hostfs_do_readlink(path, link, PATH_MAX); 894d0352d3eSAl Viro if (err == PATH_MAX) 8951da177e4SLinus Torvalds err = -E2BIG; 896e9193059SAl Viro __putname(path); 8971da177e4SLinus Torvalds } 898d0352d3eSAl Viro if (err < 0) { 899fceef393SAl Viro kfree(link); 900680baacbSAl Viro return ERR_PTR(err); 901d0352d3eSAl Viro } 902d0352d3eSAl Viro } else { 903680baacbSAl Viro return ERR_PTR(-ENOMEM); 9041da177e4SLinus Torvalds } 9051da177e4SLinus Torvalds 906fceef393SAl Viro set_delayed_call(done, kfree_link, link); 907fceef393SAl Viro return link; 908d0352d3eSAl Viro } 909d0352d3eSAl Viro 910d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops = { 9116b255391SAl Viro .get_link = hostfs_get_link, 9121da177e4SLinus Torvalds }; 9131da177e4SLinus Torvalds 9141da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9151da177e4SLinus Torvalds { 9161da177e4SLinus Torvalds struct inode *root_inode; 91775e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9181da177e4SLinus Torvalds int err; 9191da177e4SLinus Torvalds 9201da177e4SLinus Torvalds sb->s_blocksize = 1024; 9211da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9221da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9231da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 924b26d4cd3SAl Viro sb->s_d_op = &simple_dentry_operations; 925752fa51eSWolfgang Illmeyer sb->s_maxbytes = MAX_LFS_FILESIZE; 9261da177e4SLinus Torvalds 927b58c4e96SAndy Shevchenko /* NULL is printed as '(null)' by printf(): avoid that. */ 92875e8defbSPaolo 'Blaisorblade' Giarrusso if (req_root == NULL) 92975e8defbSPaolo 'Blaisorblade' Giarrusso req_root = ""; 9301da177e4SLinus Torvalds 9311da177e4SLinus Torvalds err = -ENOMEM; 932601d2c38SAl Viro sb->s_fs_info = host_root_path = 933b58c4e96SAndy Shevchenko kasprintf(GFP_KERNEL, "%s/%s", root_ino, req_root); 93475e8defbSPaolo 'Blaisorblade' Giarrusso if (host_root_path == NULL) 9351da177e4SLinus Torvalds goto out; 9361da177e4SLinus Torvalds 93752b209f7SAl Viro root_inode = new_inode(sb); 93852b209f7SAl Viro if (!root_inode) 939601d2c38SAl Viro goto out; 9401da177e4SLinus Torvalds 9414754b825SAl Viro err = read_name(root_inode, host_root_path); 9424754b825SAl Viro if (err) 9434754b825SAl Viro goto out_put; 94452b209f7SAl Viro 9454754b825SAl Viro if (S_ISLNK(root_inode->i_mode)) { 94652b209f7SAl Viro char *name = follow_link(host_root_path); 9478a545f18SDan Carpenter if (IS_ERR(name)) { 94852b209f7SAl Viro err = PTR_ERR(name); 9498a545f18SDan Carpenter goto out_put; 9508a545f18SDan Carpenter } 95152b209f7SAl Viro err = read_name(root_inode, name); 95252b209f7SAl Viro kfree(name); 9531da177e4SLinus Torvalds if (err) 9541da177e4SLinus Torvalds goto out_put; 9554754b825SAl Viro } 9561da177e4SLinus Torvalds 9571da177e4SLinus Torvalds err = -ENOMEM; 95848fde701SAl Viro sb->s_root = d_make_root(root_inode); 9591da177e4SLinus Torvalds if (sb->s_root == NULL) 96048fde701SAl Viro goto out; 9611da177e4SLinus Torvalds 962f1adc05eSJeff Dike return 0; 9631da177e4SLinus Torvalds 9641da177e4SLinus Torvalds out_put: 9651da177e4SLinus Torvalds iput(root_inode); 9661da177e4SLinus Torvalds out: 967f1adc05eSJeff Dike return err; 9681da177e4SLinus Torvalds } 9691da177e4SLinus Torvalds 9703c26ff6eSAl Viro static struct dentry *hostfs_read_sb(struct file_system_type *type, 9711da177e4SLinus Torvalds int flags, const char *dev_name, 9723c26ff6eSAl Viro void *data) 9731da177e4SLinus Torvalds { 9743c26ff6eSAl Viro return mount_nodev(type, flags, data, hostfs_fill_sb_common); 9751da177e4SLinus Torvalds } 9761da177e4SLinus Torvalds 977601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s) 978601d2c38SAl Viro { 979601d2c38SAl Viro kill_anon_super(s); 980601d2c38SAl Viro kfree(s->s_fs_info); 981601d2c38SAl Viro } 982601d2c38SAl Viro 9831da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 9841da177e4SLinus Torvalds .owner = THIS_MODULE, 9851da177e4SLinus Torvalds .name = "hostfs", 9863c26ff6eSAl Viro .mount = hostfs_read_sb, 987601d2c38SAl Viro .kill_sb = hostfs_kill_sb, 9881da177e4SLinus Torvalds .fs_flags = 0, 9891da177e4SLinus Torvalds }; 9903e64fe5bSEric W. Biederman MODULE_ALIAS_FS("hostfs"); 9911da177e4SLinus Torvalds 9921da177e4SLinus Torvalds static int __init init_hostfs(void) 9931da177e4SLinus Torvalds { 994f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 9951da177e4SLinus Torvalds } 9961da177e4SLinus Torvalds 9971da177e4SLinus Torvalds static void __exit exit_hostfs(void) 9981da177e4SLinus Torvalds { 9991da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 10001da177e4SLinus Torvalds } 10011da177e4SLinus Torvalds 10021da177e4SLinus Torvalds module_init(init_hostfs) 10031da177e4SLinus Torvalds module_exit(exit_hostfs) 10041da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1005