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 37a15f1e41SJohannes Berg static struct kmem_cache *hostfs_inode_cache; 38a15f1e41SJohannes Berg 391da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 40a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 411da177e4SLinus Torvalds static int append = 0; 421da177e4SLinus Torvalds 4392e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 4492e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 45d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops; 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds #ifndef MODULE 481da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds char *ptr; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds ptr = strchr(options, ','); 531da177e4SLinus Torvalds if (ptr != NULL) 541da177e4SLinus Torvalds *ptr++ = '\0'; 551da177e4SLinus Torvalds if (*options != '\0') 561da177e4SLinus Torvalds root_ino = options; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds options = ptr; 591da177e4SLinus Torvalds while (options) { 601da177e4SLinus Torvalds ptr = strchr(options, ','); 611da177e4SLinus Torvalds if (ptr != NULL) 621da177e4SLinus Torvalds *ptr++ = '\0'; 631da177e4SLinus Torvalds if (*options != '\0') { 641da177e4SLinus Torvalds if (!strcmp(options, "append")) 651da177e4SLinus Torvalds append = 1; 661da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 671da177e4SLinus Torvalds options); 681da177e4SLinus Torvalds } 691da177e4SLinus Torvalds options = ptr; 701da177e4SLinus Torvalds } 71f1adc05eSJeff Dike return 0; 721da177e4SLinus Torvalds } 731da177e4SLinus Torvalds 741da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 751da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 761da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 771da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 781da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 791da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 801da177e4SLinus Torvalds " it.\n" 811da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 821da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 831da177e4SLinus Torvalds ); 841da177e4SLinus Torvalds #endif 851da177e4SLinus Torvalds 86e9193059SAl Viro static char *__dentry_name(struct dentry *dentry, char *name) 87e9193059SAl Viro { 88ec2447c2SNick Piggin char *p = dentry_path_raw(dentry, name, PATH_MAX); 89e9193059SAl Viro char *root; 90e9193059SAl Viro size_t len; 91e9193059SAl Viro 92e9193059SAl Viro root = dentry->d_sb->s_fs_info; 93e9193059SAl Viro len = strlen(root); 94e9193059SAl Viro if (IS_ERR(p)) { 95e9193059SAl Viro __putname(name); 96e9193059SAl Viro return NULL; 97e9193059SAl Viro } 98aad50b1eSRichard Weinberger 99aad50b1eSRichard Weinberger /* 100aad50b1eSRichard Weinberger * This function relies on the fact that dentry_path_raw() will place 101aad50b1eSRichard Weinberger * the path name at the end of the provided buffer. 102aad50b1eSRichard Weinberger */ 103aad50b1eSRichard Weinberger BUG_ON(p + strlen(p) + 1 != name + PATH_MAX); 104aad50b1eSRichard Weinberger 105850a496fSAl Viro strlcpy(name, root, PATH_MAX); 106e9193059SAl Viro if (len > p - name) { 107e9193059SAl Viro __putname(name); 108e9193059SAl Viro return NULL; 109e9193059SAl Viro } 110c278e81bSRichard Weinberger 111c278e81bSRichard Weinberger if (p > name + len) 112c278e81bSRichard Weinberger strcpy(name + len, p); 113c278e81bSRichard Weinberger 114e9193059SAl Viro return name; 115e9193059SAl Viro } 116e9193059SAl Viro 117c5322220SAl Viro static char *dentry_name(struct dentry *dentry) 1181da177e4SLinus Torvalds { 119e9193059SAl Viro char *name = __getname(); 120e9193059SAl Viro if (!name) 121f1adc05eSJeff Dike return NULL; 1221da177e4SLinus Torvalds 1239dcc5e8aSJames Hogan return __dentry_name(dentry, name); 1241da177e4SLinus Torvalds } 1251da177e4SLinus Torvalds 126c5322220SAl Viro static char *inode_name(struct inode *ino) 1271da177e4SLinus Torvalds { 1281da177e4SLinus Torvalds struct dentry *dentry; 129ec2447c2SNick Piggin char *name; 130ec2447c2SNick Piggin 131ec2447c2SNick Piggin dentry = d_find_alias(ino); 132ec2447c2SNick Piggin if (!dentry) 133e9193059SAl Viro return NULL; 1341da177e4SLinus Torvalds 135ec2447c2SNick Piggin name = dentry_name(dentry); 136ec2447c2SNick Piggin 137ec2447c2SNick Piggin dput(dentry); 138ec2447c2SNick Piggin 139ec2447c2SNick Piggin return name; 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds static char *follow_link(char *link) 1431da177e4SLinus Torvalds { 1441da177e4SLinus Torvalds char *name, *resolved, *end; 145b58c4e96SAndy Shevchenko int n; 1461da177e4SLinus Torvalds 1477f6c411cSAl Viro name = kmalloc(PATH_MAX, GFP_KERNEL); 1487c950992SRichard Weinberger if (!name) { 1491da177e4SLinus Torvalds n = -ENOMEM; 1507c950992SRichard Weinberger goto out_free; 1511da177e4SLinus Torvalds } 1527c950992SRichard Weinberger 1537c950992SRichard Weinberger n = hostfs_do_readlink(link, name, PATH_MAX); 1541da177e4SLinus Torvalds if (n < 0) 1551da177e4SLinus Torvalds goto out_free; 1567c950992SRichard Weinberger else if (n == PATH_MAX) { 1577c950992SRichard Weinberger n = -E2BIG; 1587c950992SRichard Weinberger goto out_free; 1597c950992SRichard Weinberger } 1601da177e4SLinus Torvalds 1611da177e4SLinus Torvalds if (*name == '/') 162f1adc05eSJeff Dike return name; 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds end = strrchr(link, '/'); 1651da177e4SLinus Torvalds if (end == NULL) 166f1adc05eSJeff Dike return name; 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds *(end + 1) = '\0'; 1691da177e4SLinus Torvalds 170b58c4e96SAndy Shevchenko resolved = kasprintf(GFP_KERNEL, "%s%s", link, name); 1711da177e4SLinus Torvalds if (resolved == NULL) { 1721da177e4SLinus Torvalds n = -ENOMEM; 1731da177e4SLinus Torvalds goto out_free; 1741da177e4SLinus Torvalds } 1751da177e4SLinus Torvalds 1767f6c411cSAl Viro kfree(name); 177f1adc05eSJeff Dike return resolved; 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds out_free: 1807f6c411cSAl Viro kfree(name); 181f1adc05eSJeff Dike return ERR_PTR(n); 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds 1840a370e5dSDavid Howells static struct inode *hostfs_iget(struct super_block *sb) 1850a370e5dSDavid Howells { 18652b209f7SAl Viro struct inode *inode = new_inode(sb); 1870a370e5dSDavid Howells if (!inode) 1880a370e5dSDavid Howells return ERR_PTR(-ENOMEM); 1890a370e5dSDavid Howells return inode; 1900a370e5dSDavid Howells } 1910a370e5dSDavid Howells 1929e443bc3SJames Hogan static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 1931da177e4SLinus Torvalds { 19484b3db04SJeff Dike /* 19584b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 1961da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 1971da177e4SLinus Torvalds * so we convert them here 1981da177e4SLinus Torvalds */ 1991da177e4SLinus Torvalds int err; 2001da177e4SLinus Torvalds long long f_blocks; 2011da177e4SLinus Torvalds long long f_bfree; 2021da177e4SLinus Torvalds long long f_bavail; 2031da177e4SLinus Torvalds long long f_files; 2041da177e4SLinus Torvalds long long f_ffree; 2051da177e4SLinus Torvalds 206601d2c38SAl Viro err = do_statfs(dentry->d_sb->s_fs_info, 2071da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2081da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2091b627d57SRichard Weinberger &sf->f_namelen); 210f1adc05eSJeff Dike if (err) 211f1adc05eSJeff Dike return err; 2121da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2131da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2141da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2151da177e4SLinus Torvalds sf->f_files = f_files; 2161da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2171da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 218f1adc05eSJeff Dike return 0; 2191da177e4SLinus Torvalds } 2201da177e4SLinus Torvalds 2211da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2221da177e4SLinus Torvalds { 2231da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2241da177e4SLinus Torvalds 225a15f1e41SJohannes Berg hi = kmem_cache_alloc(hostfs_inode_cache, GFP_KERNEL_ACCOUNT); 2261da177e4SLinus Torvalds if (hi == NULL) 227f1adc05eSJeff Dike return NULL; 228601d2c38SAl Viro hi->fd = -1; 229371fdab1SJames Hogan hi->mode = 0; 2301da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 23169886e67SRichard Weinberger mutex_init(&hi->open_mutex); 232f1adc05eSJeff Dike return &hi->vfs_inode; 2331da177e4SLinus Torvalds } 2341da177e4SLinus Torvalds 235e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode) 2361da177e4SLinus Torvalds { 23791b0abe3SJohannes Weiner truncate_inode_pages_final(&inode->i_data); 238dbd5768fSJan Kara clear_inode(inode); 2391da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2401da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2411da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2421da177e4SLinus Torvalds } 2431da177e4SLinus Torvalds } 2441da177e4SLinus Torvalds 24508ccfc5cSAl Viro static void hostfs_free_inode(struct inode *inode) 246fa0d7e3dSNick Piggin { 247a15f1e41SJohannes Berg kmem_cache_free(hostfs_inode_cache, HOSTFS_I(inode)); 248fa0d7e3dSNick Piggin } 249fa0d7e3dSNick Piggin 25034c80b1dSAl Viro static int hostfs_show_options(struct seq_file *seq, struct dentry *root) 251dd2cc4dfSMiklos Szeredi { 25234c80b1dSAl Viro const char *root_path = root->d_sb->s_fs_info; 253dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1; 254dd2cc4dfSMiklos Szeredi 255dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset) 256a068acf2SKees Cook seq_show_option(seq, root_path + offset, NULL); 257dd2cc4dfSMiklos Szeredi 2587f74a668SRichard Weinberger if (append) 2597f74a668SRichard Weinberger seq_puts(seq, ",append"); 2607f74a668SRichard Weinberger 261dd2cc4dfSMiklos Szeredi return 0; 262dd2cc4dfSMiklos Szeredi } 263dd2cc4dfSMiklos Szeredi 264ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 2651da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 26608ccfc5cSAl Viro .free_inode = hostfs_free_inode, 267e971a6d7SAl Viro .evict_inode = hostfs_evict_inode, 2681da177e4SLinus Torvalds .statfs = hostfs_statfs, 269dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options, 2701da177e4SLinus Torvalds }; 2711da177e4SLinus Torvalds 2729e443bc3SJames Hogan static int hostfs_readdir(struct file *file, struct dir_context *ctx) 2731da177e4SLinus Torvalds { 2741da177e4SLinus Torvalds void *dir; 2751da177e4SLinus Torvalds char *name; 2761da177e4SLinus Torvalds unsigned long long next, ino; 2771da177e4SLinus Torvalds int error, len; 2783ee6bd8eSGeert Uytterhoeven unsigned int type; 2791da177e4SLinus Torvalds 280c5322220SAl Viro name = dentry_name(file->f_path.dentry); 281f1adc05eSJeff Dike if (name == NULL) 282f1adc05eSJeff Dike return -ENOMEM; 2831da177e4SLinus Torvalds dir = open_dir(name, &error); 284e9193059SAl Viro __putname(name); 285f1adc05eSJeff Dike if (dir == NULL) 286f1adc05eSJeff Dike return -error; 2878e28bc7eSAl Viro next = ctx->pos; 2880c9bd636SRichard Weinberger seek_dir(dir, next); 2893ee6bd8eSGeert Uytterhoeven while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { 2908e28bc7eSAl Viro if (!dir_emit(ctx, name, len, ino, type)) 2918e28bc7eSAl Viro break; 2928e28bc7eSAl Viro ctx->pos = next; 2931da177e4SLinus Torvalds } 2941da177e4SLinus Torvalds close_dir(dir); 295f1adc05eSJeff Dike return 0; 2961da177e4SLinus Torvalds } 2971da177e4SLinus Torvalds 2984c6dcafcSRichard Weinberger static int hostfs_open(struct inode *ino, struct file *file) 2991da177e4SLinus Torvalds { 3001da177e4SLinus Torvalds char *name; 301bd1052a2SRichard Weinberger fmode_t mode; 302f8ad850fSAl Viro int err; 303bd1052a2SRichard Weinberger int r, w, fd; 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3061da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode) 307f1adc05eSJeff Dike return 0; 3081da177e4SLinus Torvalds 309f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 3101da177e4SLinus Torvalds 311f8ad850fSAl Viro retry: 312a9d1958bSRichard Weinberger r = w = 0; 313a9d1958bSRichard Weinberger 314f8ad850fSAl Viro if (mode & FMODE_READ) 3151da177e4SLinus Torvalds r = 1; 316f8ad850fSAl Viro if (mode & FMODE_WRITE) 317112a5da7SRichard Weinberger r = w = 1; 3181da177e4SLinus Torvalds 319d692d397SAl Viro name = dentry_name(file_dentry(file)); 3201da177e4SLinus Torvalds if (name == NULL) 321f1adc05eSJeff Dike return -ENOMEM; 3221da177e4SLinus Torvalds 3231da177e4SLinus Torvalds fd = open_file(name, r, w, append); 324e9193059SAl Viro __putname(name); 325f1adc05eSJeff Dike if (fd < 0) 326f1adc05eSJeff Dike return fd; 327f8ad850fSAl Viro 32869886e67SRichard Weinberger mutex_lock(&HOSTFS_I(ino)->open_mutex); 329f8ad850fSAl Viro /* somebody else had handled it first? */ 330f8ad850fSAl Viro if ((mode & HOSTFS_I(ino)->mode) == mode) { 33169886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 332af955658SRichard Weinberger close_file(&fd); 333f8ad850fSAl Viro return 0; 334f8ad850fSAl Viro } 335f8ad850fSAl Viro if ((mode | HOSTFS_I(ino)->mode) != mode) { 336f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 33769886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 338f8ad850fSAl Viro close_file(&fd); 339f8ad850fSAl Viro goto retry; 340f8ad850fSAl Viro } 341f8ad850fSAl Viro if (HOSTFS_I(ino)->fd == -1) { 342f8ad850fSAl Viro HOSTFS_I(ino)->fd = fd; 343f8ad850fSAl Viro } else { 344f8ad850fSAl Viro err = replace_file(fd, HOSTFS_I(ino)->fd); 345f8ad850fSAl Viro close_file(&fd); 346f8ad850fSAl Viro if (err < 0) { 34769886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 348f8ad850fSAl Viro return err; 349f8ad850fSAl Viro } 350f8ad850fSAl Viro } 351f8ad850fSAl Viro HOSTFS_I(ino)->mode = mode; 35269886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex); 3531da177e4SLinus Torvalds 354f1adc05eSJeff Dike return 0; 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds 35765984ff9SRichard Weinberger static int hostfs_file_release(struct inode *inode, struct file *file) 35865984ff9SRichard Weinberger { 35965984ff9SRichard Weinberger filemap_write_and_wait(inode->i_mapping); 36065984ff9SRichard Weinberger 36165984ff9SRichard Weinberger return 0; 36265984ff9SRichard Weinberger } 36365984ff9SRichard Weinberger 3649e443bc3SJames Hogan static int hostfs_fsync(struct file *file, loff_t start, loff_t end, 3659e443bc3SJames Hogan int datasync) 3661da177e4SLinus Torvalds { 36702c24a82SJosef Bacik struct inode *inode = file->f_mapping->host; 36802c24a82SJosef Bacik int ret; 36902c24a82SJosef Bacik 3703b49c9a1SJeff Layton ret = file_write_and_wait_range(file, start, end); 37102c24a82SJosef Bacik if (ret) 37202c24a82SJosef Bacik return ret; 37302c24a82SJosef Bacik 3745955102cSAl Viro inode_lock(inode); 37502c24a82SJosef Bacik ret = fsync_file(HOSTFS_I(inode)->fd, datasync); 3765955102cSAl Viro inode_unlock(inode); 37702c24a82SJosef Bacik 37802c24a82SJosef Bacik return ret; 3791da177e4SLinus Torvalds } 3801da177e4SLinus Torvalds 3814b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3821da177e4SLinus Torvalds .llseek = generic_file_llseek, 3835ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3841568cb0eSJohannes Berg .splice_write = iter_file_splice_write, 385aad4f8bbSAl Viro .read_iter = generic_file_read_iter, 3868174202bSAl Viro .write_iter = generic_file_write_iter, 3871da177e4SLinus Torvalds .mmap = generic_file_mmap, 3884c6dcafcSRichard Weinberger .open = hostfs_open, 38965984ff9SRichard Weinberger .release = hostfs_file_release, 3901da177e4SLinus Torvalds .fsync = hostfs_fsync, 3911da177e4SLinus Torvalds }; 3921da177e4SLinus Torvalds 3934b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 3941da177e4SLinus Torvalds .llseek = generic_file_llseek, 395552a9d48SAl Viro .iterate_shared = hostfs_readdir, 3961da177e4SLinus Torvalds .read = generic_read_dir, 3974c6dcafcSRichard Weinberger .open = hostfs_open, 3984c6dcafcSRichard Weinberger .fsync = hostfs_fsync, 3991da177e4SLinus Torvalds }; 4001da177e4SLinus Torvalds 4019e443bc3SJames Hogan static int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4021da177e4SLinus Torvalds { 4031da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4041da177e4SLinus Torvalds struct inode *inode = mapping->host; 4051da177e4SLinus Torvalds char *buffer; 406af6aa1b9SRichard Weinberger loff_t base = page_offset(page); 40709cbfeafSKirill A. Shutemov int count = PAGE_SIZE; 40809cbfeafSKirill A. Shutemov int end_index = inode->i_size >> PAGE_SHIFT; 4091da177e4SLinus Torvalds int err; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds if (page->index >= end_index) 41209cbfeafSKirill A. Shutemov count = inode->i_size & (PAGE_SIZE-1); 4131da177e4SLinus Torvalds 4141da177e4SLinus Torvalds buffer = kmap(page); 4151da177e4SLinus Torvalds 4161da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4171da177e4SLinus Torvalds if (err != count) { 4181da177e4SLinus Torvalds ClearPageUptodate(page); 4191da177e4SLinus Torvalds goto out; 4201da177e4SLinus Torvalds } 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds if (base > inode->i_size) 4231da177e4SLinus Torvalds inode->i_size = base; 4241da177e4SLinus Torvalds 4251da177e4SLinus Torvalds if (PageError(page)) 4261da177e4SLinus Torvalds ClearPageError(page); 4271da177e4SLinus Torvalds err = 0; 4281da177e4SLinus Torvalds 4291da177e4SLinus Torvalds out: 4301da177e4SLinus Torvalds kunmap(page); 4311da177e4SLinus Torvalds 4321da177e4SLinus Torvalds unlock_page(page); 4331da177e4SLinus Torvalds return err; 4341da177e4SLinus Torvalds } 4351da177e4SLinus Torvalds 4369e443bc3SJames Hogan static int hostfs_readpage(struct file *file, struct page *page) 4371da177e4SLinus Torvalds { 4381da177e4SLinus Torvalds char *buffer; 439af6aa1b9SRichard Weinberger loff_t start = page_offset(page); 440b86b413aSRichard Weinberger int bytes_read, ret = 0; 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds buffer = kmap(page); 44341761ddfSRichard Weinberger bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 44409cbfeafSKirill A. Shutemov PAGE_SIZE); 44541761ddfSRichard Weinberger if (bytes_read < 0) { 446b86b413aSRichard Weinberger ClearPageUptodate(page); 447b86b413aSRichard Weinberger SetPageError(page); 44841761ddfSRichard Weinberger ret = bytes_read; 44984b3db04SJeff Dike goto out; 45041761ddfSRichard Weinberger } 4511da177e4SLinus Torvalds 45209cbfeafSKirill A. Shutemov memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read); 4531da177e4SLinus Torvalds 454b86b413aSRichard Weinberger ClearPageError(page); 4551da177e4SLinus Torvalds SetPageUptodate(page); 456b86b413aSRichard Weinberger 4571da177e4SLinus Torvalds out: 458b86b413aSRichard Weinberger flush_dcache_page(page); 4591da177e4SLinus Torvalds kunmap(page); 4601da177e4SLinus Torvalds unlock_page(page); 46141761ddfSRichard Weinberger return ret; 4621da177e4SLinus Torvalds } 4631da177e4SLinus Torvalds 4649e443bc3SJames Hogan static int hostfs_write_begin(struct file *file, struct address_space *mapping, 465ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 466ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4671da177e4SLinus Torvalds { 46809cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT; 469ae361ff4SNick Piggin 47054566b2cSNick Piggin *pagep = grab_cache_page_write_begin(mapping, index, flags); 471ae361ff4SNick Piggin if (!*pagep) 472ae361ff4SNick Piggin return -ENOMEM; 473ae361ff4SNick Piggin return 0; 474ae361ff4SNick Piggin } 475ae361ff4SNick Piggin 4769e443bc3SJames Hogan static int hostfs_write_end(struct file *file, struct address_space *mapping, 477ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 478ae361ff4SNick Piggin struct page *page, void *fsdata) 479ae361ff4SNick Piggin { 480ae361ff4SNick Piggin struct inode *inode = mapping->host; 481ae361ff4SNick Piggin void *buffer; 48209cbfeafSKirill A. Shutemov unsigned from = pos & (PAGE_SIZE - 1); 4831da177e4SLinus Torvalds int err; 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds buffer = kmap(page); 486ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4871da177e4SLinus Torvalds kunmap(page); 4881da177e4SLinus Torvalds 48909cbfeafSKirill A. Shutemov if (!PageUptodate(page) && err == PAGE_SIZE) 490ae361ff4SNick Piggin SetPageUptodate(page); 4911da177e4SLinus Torvalds 49284b3db04SJeff Dike /* 49384b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 494ae361ff4SNick Piggin * i_size against the last byte written. 495ae361ff4SNick Piggin */ 496ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 497ae361ff4SNick Piggin inode->i_size = pos; 498ae361ff4SNick Piggin unlock_page(page); 49909cbfeafSKirill A. Shutemov put_page(page); 50030f04a4eSPaolo 'Blaisorblade' Giarrusso 501f1adc05eSJeff Dike return err; 5021da177e4SLinus Torvalds } 5031da177e4SLinus Torvalds 504f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 5051da177e4SLinus Torvalds .writepage = hostfs_writepage, 5061da177e4SLinus Torvalds .readpage = hostfs_readpage, 507ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 508ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 509ae361ff4SNick Piggin .write_end = hostfs_write_end, 5101da177e4SLinus Torvalds }; 5111da177e4SLinus Torvalds 5124754b825SAl Viro static int read_name(struct inode *ino, char *name) 5131da177e4SLinus Torvalds { 5144754b825SAl Viro dev_t rdev; 5154754b825SAl Viro struct hostfs_stat st; 5164754b825SAl Viro int err = stat_file(name, &st, -1); 5174754b825SAl Viro if (err) 5184754b825SAl Viro return err; 5191da177e4SLinus Torvalds 5201da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5214754b825SAl Viro rdev = MKDEV(st.maj, st.min); 5221da177e4SLinus Torvalds 5234754b825SAl Viro switch (st.mode & S_IFMT) { 5244754b825SAl Viro case S_IFLNK: 525d0352d3eSAl Viro ino->i_op = &hostfs_link_iops; 5264754b825SAl Viro break; 5274754b825SAl Viro case S_IFDIR: 5284754b825SAl Viro ino->i_op = &hostfs_dir_iops; 5294754b825SAl Viro ino->i_fop = &hostfs_dir_fops; 5304754b825SAl Viro break; 5314754b825SAl Viro case S_IFCHR: 5324754b825SAl Viro case S_IFBLK: 5334754b825SAl Viro case S_IFIFO: 5344754b825SAl Viro case S_IFSOCK: 5354754b825SAl Viro init_special_inode(ino, st.mode & S_IFMT, rdev); 5364754b825SAl Viro ino->i_op = &hostfs_iops; 5374754b825SAl Viro break; 5382ad2dca6SRichard Weinberger case S_IFREG: 5394754b825SAl Viro ino->i_op = &hostfs_iops; 5404754b825SAl Viro ino->i_fop = &hostfs_file_fops; 5414754b825SAl Viro ino->i_mapping->a_ops = &hostfs_aops; 5422ad2dca6SRichard Weinberger break; 5432ad2dca6SRichard Weinberger default: 5442ad2dca6SRichard Weinberger return -EIO; 5451da177e4SLinus Torvalds } 5464754b825SAl Viro 5474754b825SAl Viro ino->i_ino = st.ino; 5484754b825SAl Viro ino->i_mode = st.mode; 549bfe86848SMiklos Szeredi set_nlink(ino, st.nlink); 55029f82ae5SEric W. Biederman i_uid_write(ino, st.uid); 55129f82ae5SEric W. Biederman i_gid_write(ino, st.gid); 552bca30265SArnd Bergmann ino->i_atime = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec }; 553bca30265SArnd Bergmann ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec }; 554bca30265SArnd Bergmann ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec }; 5554754b825SAl Viro ino->i_size = st.size; 5564754b825SAl Viro ino->i_blocks = st.blocks; 5574754b825SAl Viro return 0; 5581da177e4SLinus Torvalds } 5591da177e4SLinus Torvalds 560549c7297SChristian Brauner static int hostfs_create(struct user_namespace *mnt_userns, struct inode *dir, 561549c7297SChristian Brauner struct dentry *dentry, umode_t mode, bool excl) 5621da177e4SLinus Torvalds { 5631da177e4SLinus Torvalds struct inode *inode; 5641da177e4SLinus Torvalds char *name; 5651da177e4SLinus Torvalds int error, fd; 5661da177e4SLinus Torvalds 5670a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 5680a370e5dSDavid Howells if (IS_ERR(inode)) { 5690a370e5dSDavid Howells error = PTR_ERR(inode); 57084b3db04SJeff Dike goto out; 5710a370e5dSDavid Howells } 5721da177e4SLinus Torvalds 5731da177e4SLinus Torvalds error = -ENOMEM; 574c5322220SAl Viro name = dentry_name(dentry); 5751da177e4SLinus Torvalds if (name == NULL) 5761da177e4SLinus Torvalds goto out_put; 5771da177e4SLinus Torvalds 578a718c922SRichard Weinberger fd = file_create(name, mode & 0777); 5794754b825SAl Viro if (fd < 0) 5801da177e4SLinus Torvalds error = fd; 5814754b825SAl Viro else 5825e2df28cSAl Viro error = read_name(inode, name); 5831da177e4SLinus Torvalds 584e9193059SAl Viro __putname(name); 5851da177e4SLinus Torvalds if (error) 5861da177e4SLinus Torvalds goto out_put; 5871da177e4SLinus Torvalds 5881da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5891da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 5901da177e4SLinus Torvalds d_instantiate(dentry, inode); 591f1adc05eSJeff Dike return 0; 5921da177e4SLinus Torvalds 5931da177e4SLinus Torvalds out_put: 5941da177e4SLinus Torvalds iput(inode); 5951da177e4SLinus Torvalds out: 596f1adc05eSJeff Dike return error; 5971da177e4SLinus Torvalds } 5981da177e4SLinus Torvalds 5999e443bc3SJames Hogan static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 60000cd8dd3SAl Viro unsigned int flags) 6011da177e4SLinus Torvalds { 6021da177e4SLinus Torvalds struct inode *inode; 6031da177e4SLinus Torvalds char *name; 6041da177e4SLinus Torvalds int err; 6051da177e4SLinus Torvalds 6060a370e5dSDavid Howells inode = hostfs_iget(ino->i_sb); 60750f30740SAl Viro if (IS_ERR(inode)) 6081da177e4SLinus Torvalds goto out; 6091da177e4SLinus Torvalds 6101da177e4SLinus Torvalds err = -ENOMEM; 611c5322220SAl Viro name = dentry_name(dentry); 61250f30740SAl Viro if (name) { 6131da177e4SLinus Torvalds err = read_name(inode, name); 614e9193059SAl Viro __putname(name); 6151da177e4SLinus Torvalds } 61650f30740SAl Viro if (err) { 6171da177e4SLinus Torvalds iput(inode); 61850f30740SAl Viro inode = (err == -ENOENT) ? NULL : ERR_PTR(err); 61950f30740SAl Viro } 6201da177e4SLinus Torvalds out: 62150f30740SAl Viro return d_splice_alias(inode, dentry); 6221da177e4SLinus Torvalds } 6231da177e4SLinus Torvalds 6249e443bc3SJames Hogan static int hostfs_link(struct dentry *to, struct inode *ino, 6259e443bc3SJames Hogan struct dentry *from) 6261da177e4SLinus Torvalds { 6271da177e4SLinus Torvalds char *from_name, *to_name; 6281da177e4SLinus Torvalds int err; 6291da177e4SLinus Torvalds 630c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 631f1adc05eSJeff Dike return -ENOMEM; 632c5322220SAl Viro to_name = dentry_name(to); 6331da177e4SLinus Torvalds if (to_name == NULL) { 634e9193059SAl Viro __putname(from_name); 635f1adc05eSJeff Dike return -ENOMEM; 6361da177e4SLinus Torvalds } 6371da177e4SLinus Torvalds err = link_file(to_name, from_name); 638e9193059SAl Viro __putname(from_name); 639e9193059SAl Viro __putname(to_name); 640f1adc05eSJeff Dike return err; 6411da177e4SLinus Torvalds } 6421da177e4SLinus Torvalds 6439e443bc3SJames Hogan static int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6441da177e4SLinus Torvalds { 6451da177e4SLinus Torvalds char *file; 6461da177e4SLinus Torvalds int err; 6471da177e4SLinus Torvalds 6481da177e4SLinus Torvalds if (append) 649f1adc05eSJeff Dike return -EPERM; 6501da177e4SLinus Torvalds 651f8d7e187SAl Viro if ((file = dentry_name(dentry)) == NULL) 652f8d7e187SAl Viro return -ENOMEM; 653f8d7e187SAl Viro 6541da177e4SLinus Torvalds err = unlink_file(file); 655e9193059SAl Viro __putname(file); 656f1adc05eSJeff Dike return err; 6571da177e4SLinus Torvalds } 6581da177e4SLinus Torvalds 659549c7297SChristian Brauner static int hostfs_symlink(struct user_namespace *mnt_userns, struct inode *ino, 660549c7297SChristian Brauner struct dentry *dentry, const char *to) 6611da177e4SLinus Torvalds { 6621da177e4SLinus Torvalds char *file; 6631da177e4SLinus Torvalds int err; 6641da177e4SLinus Torvalds 665c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 666f1adc05eSJeff Dike return -ENOMEM; 6671da177e4SLinus Torvalds err = make_symlink(file, to); 668e9193059SAl Viro __putname(file); 669f1adc05eSJeff Dike return err; 6701da177e4SLinus Torvalds } 6711da177e4SLinus Torvalds 672549c7297SChristian Brauner static int hostfs_mkdir(struct user_namespace *mnt_userns, struct inode *ino, 673549c7297SChristian Brauner struct dentry *dentry, umode_t mode) 6741da177e4SLinus Torvalds { 6751da177e4SLinus Torvalds char *file; 6761da177e4SLinus Torvalds int err; 6771da177e4SLinus Torvalds 678c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 679f1adc05eSJeff Dike return -ENOMEM; 6801da177e4SLinus Torvalds err = do_mkdir(file, mode); 681e9193059SAl Viro __putname(file); 682f1adc05eSJeff Dike return err; 6831da177e4SLinus Torvalds } 6841da177e4SLinus Torvalds 6859e443bc3SJames Hogan static int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 6861da177e4SLinus Torvalds { 6871da177e4SLinus Torvalds char *file; 6881da177e4SLinus Torvalds int err; 6891da177e4SLinus Torvalds 690c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 691f1adc05eSJeff Dike return -ENOMEM; 6926380161cSDominik Brodowski err = hostfs_do_rmdir(file); 693e9193059SAl Viro __putname(file); 694f1adc05eSJeff Dike return err; 6951da177e4SLinus Torvalds } 6961da177e4SLinus Torvalds 697549c7297SChristian Brauner static int hostfs_mknod(struct user_namespace *mnt_userns, struct inode *dir, 698549c7297SChristian Brauner struct dentry *dentry, umode_t mode, dev_t dev) 6991da177e4SLinus Torvalds { 7001da177e4SLinus Torvalds struct inode *inode; 7011da177e4SLinus Torvalds char *name; 7020a370e5dSDavid Howells int err; 7031da177e4SLinus Torvalds 7040a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 7050a370e5dSDavid Howells if (IS_ERR(inode)) { 7060a370e5dSDavid Howells err = PTR_ERR(inode); 7071da177e4SLinus Torvalds goto out; 7080a370e5dSDavid Howells } 7091da177e4SLinus Torvalds 7101da177e4SLinus Torvalds err = -ENOMEM; 711c5322220SAl Viro name = dentry_name(dentry); 7121da177e4SLinus Torvalds if (name == NULL) 7131da177e4SLinus Torvalds goto out_put; 7141da177e4SLinus Torvalds 71588f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 7169f2dfda2SVegard Nossum if (err) 7171da177e4SLinus Torvalds goto out_free; 7181da177e4SLinus Torvalds 7191da177e4SLinus Torvalds err = read_name(inode, name); 720e9193059SAl Viro __putname(name); 7215e2df28cSAl Viro if (err) 7225e2df28cSAl Viro goto out_put; 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds d_instantiate(dentry, inode); 725f1adc05eSJeff Dike return 0; 7261da177e4SLinus Torvalds 7271da177e4SLinus Torvalds out_free: 728e9193059SAl Viro __putname(name); 7291da177e4SLinus Torvalds out_put: 7301da177e4SLinus Torvalds iput(inode); 7311da177e4SLinus Torvalds out: 732f1adc05eSJeff Dike return err; 7331da177e4SLinus Torvalds } 7341da177e4SLinus Torvalds 735549c7297SChristian Brauner static int hostfs_rename2(struct user_namespace *mnt_userns, 736549c7297SChristian Brauner struct inode *old_dir, struct dentry *old_dentry, 7379a423bb6SMiklos Szeredi struct inode *new_dir, struct dentry *new_dentry, 7389a423bb6SMiklos Szeredi unsigned int flags) 7391da177e4SLinus Torvalds { 7409a423bb6SMiklos Szeredi char *old_name, *new_name; 7411da177e4SLinus Torvalds int err; 7421da177e4SLinus Torvalds 7439a423bb6SMiklos Szeredi if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) 7449a423bb6SMiklos Szeredi return -EINVAL; 7459a423bb6SMiklos Szeredi 7469a423bb6SMiklos Szeredi old_name = dentry_name(old_dentry); 7479a423bb6SMiklos Szeredi if (old_name == NULL) 748f1adc05eSJeff Dike return -ENOMEM; 7499a423bb6SMiklos Szeredi new_name = dentry_name(new_dentry); 7509a423bb6SMiklos Szeredi if (new_name == NULL) { 7519a423bb6SMiklos Szeredi __putname(old_name); 752f1adc05eSJeff Dike return -ENOMEM; 7531da177e4SLinus Torvalds } 7549a423bb6SMiklos Szeredi if (!flags) 7559a423bb6SMiklos Szeredi err = rename_file(old_name, new_name); 7569a423bb6SMiklos Szeredi else 7579a423bb6SMiklos Szeredi err = rename2_file(old_name, new_name, flags); 7589a423bb6SMiklos Szeredi 7599a423bb6SMiklos Szeredi __putname(old_name); 7609a423bb6SMiklos Szeredi __putname(new_name); 761f1adc05eSJeff Dike return err; 7621da177e4SLinus Torvalds } 7631da177e4SLinus Torvalds 764549c7297SChristian Brauner static int hostfs_permission(struct user_namespace *mnt_userns, 765549c7297SChristian Brauner struct inode *ino, int desired) 7661da177e4SLinus Torvalds { 7671da177e4SLinus Torvalds char *name; 7681da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7691da177e4SLinus Torvalds 77010556cb2SAl Viro if (desired & MAY_NOT_BLOCK) 771b74c79e9SNick Piggin return -ECHILD; 772b74c79e9SNick Piggin 7731da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7741da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7751da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 776c5322220SAl Viro name = inode_name(ino); 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); 785e9193059SAl Viro __putname(name); 7861da177e4SLinus Torvalds if (!err) 78747291baaSChristian Brauner err = generic_permission(&init_user_ns, ino, desired); 7881da177e4SLinus Torvalds return err; 7891da177e4SLinus Torvalds } 7901da177e4SLinus Torvalds 791549c7297SChristian Brauner static int hostfs_setattr(struct user_namespace *mnt_userns, 792549c7297SChristian Brauner struct dentry *dentry, struct iattr *attr) 7931da177e4SLinus Torvalds { 7942b0143b5SDavid Howells struct inode *inode = d_inode(dentry); 7951da177e4SLinus Torvalds struct hostfs_iattr attrs; 7961da177e4SLinus Torvalds char *name; 7971da177e4SLinus Torvalds int err; 7981da177e4SLinus Torvalds 7991025774cSChristoph Hellwig int fd = HOSTFS_I(inode)->fd; 8005822b7faSAlberto Bertogli 8012f221d6fSChristian Brauner err = setattr_prepare(&init_user_ns, dentry, attr); 8021da177e4SLinus Torvalds if (err) 8031da177e4SLinus Torvalds return err; 8041da177e4SLinus Torvalds 8051da177e4SLinus Torvalds if (append) 8061da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds attrs.ia_valid = 0; 8091da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) { 8101da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8111da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8121da177e4SLinus Torvalds } 8131da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) { 8141da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 81529f82ae5SEric W. Biederman attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); 8161da177e4SLinus Torvalds } 8171da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8181da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 81929f82ae5SEric W. Biederman attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); 8201da177e4SLinus Torvalds } 8211da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) { 8221da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8231da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8241da177e4SLinus Torvalds } 8251da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) { 8261da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 827bca30265SArnd Bergmann attrs.ia_atime = (struct hostfs_timespec) 828bca30265SArnd Bergmann { attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec }; 8291da177e4SLinus Torvalds } 8301da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8311da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 832bca30265SArnd Bergmann attrs.ia_mtime = (struct hostfs_timespec) 833bca30265SArnd Bergmann { attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec }; 8341da177e4SLinus Torvalds } 8351da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8361da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 837bca30265SArnd Bergmann attrs.ia_ctime = (struct hostfs_timespec) 838bca30265SArnd Bergmann { attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec }; 8391da177e4SLinus Torvalds } 8401da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) { 8411da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8421da177e4SLinus Torvalds } 8431da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) { 8441da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8451da177e4SLinus Torvalds } 846c5322220SAl Viro name = dentry_name(dentry); 847f1adc05eSJeff Dike if (name == NULL) 848f1adc05eSJeff Dike return -ENOMEM; 8495822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 850e9193059SAl Viro __putname(name); 8511da177e4SLinus Torvalds if (err) 852f1adc05eSJeff Dike return err; 8531da177e4SLinus Torvalds 8541025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 855bc077320SMarco Stornelli attr->ia_size != i_size_read(inode)) 8563be2be0aSMarco Stornelli truncate_setsize(inode, attr->ia_size); 8571025774cSChristoph Hellwig 8582f221d6fSChristian Brauner setattr_copy(&init_user_ns, inode, attr); 8591025774cSChristoph Hellwig mark_inode_dirty(inode); 8601025774cSChristoph Hellwig return 0; 8611da177e4SLinus Torvalds } 8621da177e4SLinus Torvalds 86392e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8641da177e4SLinus Torvalds .permission = hostfs_permission, 8651da177e4SLinus Torvalds .setattr = hostfs_setattr, 8661da177e4SLinus Torvalds }; 8671da177e4SLinus Torvalds 86892e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8691da177e4SLinus Torvalds .create = hostfs_create, 8701da177e4SLinus Torvalds .lookup = hostfs_lookup, 8711da177e4SLinus Torvalds .link = hostfs_link, 8721da177e4SLinus Torvalds .unlink = hostfs_unlink, 8731da177e4SLinus Torvalds .symlink = hostfs_symlink, 8741da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8751da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8761da177e4SLinus Torvalds .mknod = hostfs_mknod, 8772773bf00SMiklos Szeredi .rename = hostfs_rename2, 8781da177e4SLinus Torvalds .permission = hostfs_permission, 8791da177e4SLinus Torvalds .setattr = hostfs_setattr, 8801da177e4SLinus Torvalds }; 8811da177e4SLinus Torvalds 8826b255391SAl Viro static const char *hostfs_get_link(struct dentry *dentry, 883fceef393SAl Viro struct inode *inode, 884fceef393SAl Viro struct delayed_call *done) 8851da177e4SLinus Torvalds { 8866b255391SAl Viro char *link; 8876b255391SAl Viro if (!dentry) 8886b255391SAl Viro return ERR_PTR(-ECHILD); 889fceef393SAl Viro link = kmalloc(PATH_MAX, GFP_KERNEL); 890d0352d3eSAl Viro if (link) { 891d0352d3eSAl Viro char *path = dentry_name(dentry); 892d0352d3eSAl Viro int err = -ENOMEM; 893d0352d3eSAl Viro if (path) { 8943b6036d1SAl Viro err = hostfs_do_readlink(path, link, PATH_MAX); 895d0352d3eSAl Viro if (err == PATH_MAX) 8961da177e4SLinus Torvalds err = -E2BIG; 897e9193059SAl Viro __putname(path); 8981da177e4SLinus Torvalds } 899d0352d3eSAl Viro if (err < 0) { 900fceef393SAl Viro kfree(link); 901680baacbSAl Viro return ERR_PTR(err); 902d0352d3eSAl Viro } 903d0352d3eSAl Viro } else { 904680baacbSAl Viro return ERR_PTR(-ENOMEM); 9051da177e4SLinus Torvalds } 9061da177e4SLinus Torvalds 907fceef393SAl Viro set_delayed_call(done, kfree_link, link); 908fceef393SAl Viro return link; 909d0352d3eSAl Viro } 910d0352d3eSAl Viro 911d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops = { 9126b255391SAl Viro .get_link = hostfs_get_link, 9131da177e4SLinus Torvalds }; 9141da177e4SLinus Torvalds 9151da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9161da177e4SLinus Torvalds { 9171da177e4SLinus Torvalds struct inode *root_inode; 91875e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9191da177e4SLinus Torvalds int err; 9201da177e4SLinus Torvalds 9211da177e4SLinus Torvalds sb->s_blocksize = 1024; 9221da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9231da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9241da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 925b26d4cd3SAl Viro sb->s_d_op = &simple_dentry_operations; 926752fa51eSWolfgang Illmeyer sb->s_maxbytes = MAX_LFS_FILESIZE; 927*ce72750fSSjoerd Simons err = super_setup_bdi(sb); 928*ce72750fSSjoerd Simons if (err) 929*ce72750fSSjoerd Simons goto out; 9301da177e4SLinus Torvalds 931b58c4e96SAndy Shevchenko /* NULL is printed as '(null)' by printf(): 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 = 937b58c4e96SAndy Shevchenko kasprintf(GFP_KERNEL, "%s/%s", root_ino, req_root); 93875e8defbSPaolo 'Blaisorblade' Giarrusso if (host_root_path == NULL) 9391da177e4SLinus Torvalds goto out; 9401da177e4SLinus Torvalds 94152b209f7SAl Viro root_inode = new_inode(sb); 94252b209f7SAl Viro if (!root_inode) 943601d2c38SAl Viro goto out; 9441da177e4SLinus Torvalds 9454754b825SAl Viro err = read_name(root_inode, host_root_path); 9464754b825SAl Viro if (err) 9474754b825SAl Viro goto out_put; 94852b209f7SAl Viro 9494754b825SAl Viro if (S_ISLNK(root_inode->i_mode)) { 95052b209f7SAl Viro char *name = follow_link(host_root_path); 9518a545f18SDan Carpenter if (IS_ERR(name)) { 95252b209f7SAl Viro err = PTR_ERR(name); 9538a545f18SDan Carpenter goto out_put; 9548a545f18SDan Carpenter } 95552b209f7SAl Viro err = read_name(root_inode, name); 95652b209f7SAl Viro kfree(name); 9571da177e4SLinus Torvalds if (err) 9581da177e4SLinus Torvalds goto out_put; 9594754b825SAl Viro } 9601da177e4SLinus Torvalds 9611da177e4SLinus Torvalds err = -ENOMEM; 96248fde701SAl Viro sb->s_root = d_make_root(root_inode); 9631da177e4SLinus Torvalds if (sb->s_root == NULL) 96448fde701SAl Viro goto out; 9651da177e4SLinus Torvalds 966f1adc05eSJeff Dike return 0; 9671da177e4SLinus Torvalds 9681da177e4SLinus Torvalds out_put: 9691da177e4SLinus Torvalds iput(root_inode); 9701da177e4SLinus Torvalds out: 971f1adc05eSJeff Dike return err; 9721da177e4SLinus Torvalds } 9731da177e4SLinus Torvalds 9743c26ff6eSAl Viro static struct dentry *hostfs_read_sb(struct file_system_type *type, 9751da177e4SLinus Torvalds int flags, const char *dev_name, 9763c26ff6eSAl Viro void *data) 9771da177e4SLinus Torvalds { 9783c26ff6eSAl Viro return mount_nodev(type, flags, data, hostfs_fill_sb_common); 9791da177e4SLinus Torvalds } 9801da177e4SLinus Torvalds 981601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s) 982601d2c38SAl Viro { 983601d2c38SAl Viro kill_anon_super(s); 984601d2c38SAl Viro kfree(s->s_fs_info); 985601d2c38SAl Viro } 986601d2c38SAl Viro 9871da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 9881da177e4SLinus Torvalds .owner = THIS_MODULE, 9891da177e4SLinus Torvalds .name = "hostfs", 9903c26ff6eSAl Viro .mount = hostfs_read_sb, 991601d2c38SAl Viro .kill_sb = hostfs_kill_sb, 9921da177e4SLinus Torvalds .fs_flags = 0, 9931da177e4SLinus Torvalds }; 9943e64fe5bSEric W. Biederman MODULE_ALIAS_FS("hostfs"); 9951da177e4SLinus Torvalds 9961da177e4SLinus Torvalds static int __init init_hostfs(void) 9971da177e4SLinus Torvalds { 998a15f1e41SJohannes Berg hostfs_inode_cache = KMEM_CACHE(hostfs_inode_info, 0); 999a15f1e41SJohannes Berg if (!hostfs_inode_cache) 1000a15f1e41SJohannes Berg return -ENOMEM; 1001f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 10021da177e4SLinus Torvalds } 10031da177e4SLinus Torvalds 10041da177e4SLinus Torvalds static void __exit exit_hostfs(void) 10051da177e4SLinus Torvalds { 10061da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 1007a15f1e41SJohannes Berg kmem_cache_destroy(hostfs_inode_cache); 10081da177e4SLinus Torvalds } 10091da177e4SLinus Torvalds 10101da177e4SLinus Torvalds module_init(init_hostfs) 10111da177e4SLinus Torvalds module_exit(exit_hostfs) 10121da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1013