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; 271da177e4SLinus Torvalds }; 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) 301da177e4SLinus Torvalds { 31f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode); 321da177e4SLinus Torvalds } 331da177e4SLinus Torvalds 34496ad9aaSAl Viro #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file)) 351da177e4SLinus Torvalds 36fe15ce44SNick Piggin static int hostfs_d_delete(const struct dentry *dentry) 371da177e4SLinus Torvalds { 38f1adc05eSJeff Dike return 1; 391da177e4SLinus Torvalds } 401da177e4SLinus Torvalds 41e16404edSAl Viro static const struct dentry_operations hostfs_dentry_ops = { 421da177e4SLinus Torvalds .d_delete = hostfs_d_delete, 431da177e4SLinus Torvalds }; 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 46a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 471da177e4SLinus Torvalds static int append = 0; 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; 51d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops; 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 92e9193059SAl Viro static char *__dentry_name(struct dentry *dentry, char *name) 93e9193059SAl Viro { 94ec2447c2SNick Piggin char *p = dentry_path_raw(dentry, name, PATH_MAX); 95e9193059SAl Viro char *root; 96e9193059SAl Viro size_t len; 97e9193059SAl Viro 98e9193059SAl Viro root = dentry->d_sb->s_fs_info; 99e9193059SAl Viro len = strlen(root); 100e9193059SAl Viro if (IS_ERR(p)) { 101e9193059SAl Viro __putname(name); 102e9193059SAl Viro return NULL; 103e9193059SAl Viro } 104850a496fSAl Viro strlcpy(name, root, PATH_MAX); 105e9193059SAl Viro if (len > p - name) { 106e9193059SAl Viro __putname(name); 107e9193059SAl Viro return NULL; 108e9193059SAl Viro } 109e9193059SAl Viro if (p > name + len) { 110e9193059SAl Viro char *s = name + len; 111e9193059SAl Viro while ((*s++ = *p++) != '\0') 112e9193059SAl Viro ; 113e9193059SAl Viro } 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 int len, n; 1451da177e4SLinus Torvalds char *name, *resolved, *end; 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds len = 64; 1481da177e4SLinus Torvalds while (1) { 1491da177e4SLinus Torvalds n = -ENOMEM; 1501da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1511da177e4SLinus Torvalds if (name == NULL) 1521da177e4SLinus Torvalds goto out; 1531da177e4SLinus Torvalds 154ea7e743eSWANG Cong n = hostfs_do_readlink(link, name, len); 1551da177e4SLinus Torvalds if (n < len) 1561da177e4SLinus Torvalds break; 1571da177e4SLinus Torvalds len *= 2; 1581da177e4SLinus Torvalds kfree(name); 1591da177e4SLinus Torvalds } 1601da177e4SLinus Torvalds if (n < 0) 1611da177e4SLinus Torvalds goto out_free; 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds if (*name == '/') 164f1adc05eSJeff Dike return name; 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds end = strrchr(link, '/'); 1671da177e4SLinus Torvalds if (end == NULL) 168f1adc05eSJeff Dike return name; 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds *(end + 1) = '\0'; 1711da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1721da177e4SLinus Torvalds 1731da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 1741da177e4SLinus Torvalds if (resolved == NULL) { 1751da177e4SLinus Torvalds n = -ENOMEM; 1761da177e4SLinus Torvalds goto out_free; 1771da177e4SLinus Torvalds } 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 1801da177e4SLinus Torvalds kfree(name); 1811da177e4SLinus Torvalds kfree(link); 182f1adc05eSJeff Dike return resolved; 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds out_free: 1851da177e4SLinus Torvalds kfree(name); 1861da177e4SLinus Torvalds out: 187f1adc05eSJeff Dike return ERR_PTR(n); 1881da177e4SLinus Torvalds } 1891da177e4SLinus Torvalds 1900a370e5dSDavid Howells static struct inode *hostfs_iget(struct super_block *sb) 1910a370e5dSDavid Howells { 19252b209f7SAl Viro struct inode *inode = new_inode(sb); 1930a370e5dSDavid Howells if (!inode) 1940a370e5dSDavid Howells return ERR_PTR(-ENOMEM); 1950a370e5dSDavid Howells return inode; 1960a370e5dSDavid Howells } 1970a370e5dSDavid Howells 198726c3342SDavid Howells int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 1991da177e4SLinus Torvalds { 20084b3db04SJeff Dike /* 20184b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 2021da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 2031da177e4SLinus Torvalds * so we convert them here 2041da177e4SLinus Torvalds */ 2051da177e4SLinus Torvalds int err; 2061da177e4SLinus Torvalds long long f_blocks; 2071da177e4SLinus Torvalds long long f_bfree; 2081da177e4SLinus Torvalds long long f_bavail; 2091da177e4SLinus Torvalds long long f_files; 2101da177e4SLinus Torvalds long long f_ffree; 2111da177e4SLinus Torvalds 212601d2c38SAl Viro err = do_statfs(dentry->d_sb->s_fs_info, 2131da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2141da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2151b627d57SRichard Weinberger &sf->f_namelen); 216f1adc05eSJeff Dike if (err) 217f1adc05eSJeff Dike return err; 2181da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2191da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2201da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2211da177e4SLinus Torvalds sf->f_files = f_files; 2221da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2231da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 224f1adc05eSJeff Dike return 0; 2251da177e4SLinus Torvalds } 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2281da177e4SLinus Torvalds { 2291da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2301da177e4SLinus Torvalds 231371fdab1SJames Hogan hi = kmalloc(sizeof(*hi), GFP_KERNEL); 2321da177e4SLinus Torvalds if (hi == NULL) 233f1adc05eSJeff Dike return NULL; 234601d2c38SAl Viro hi->fd = -1; 235371fdab1SJames Hogan hi->mode = 0; 2361da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 237f1adc05eSJeff Dike return &hi->vfs_inode; 2381da177e4SLinus Torvalds } 2391da177e4SLinus Torvalds 240e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode) 2411da177e4SLinus Torvalds { 242fef26658SMark Fasheh truncate_inode_pages(&inode->i_data, 0); 243dbd5768fSJan Kara clear_inode(inode); 2441da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2451da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2461da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 250fa0d7e3dSNick Piggin static void hostfs_i_callback(struct rcu_head *head) 251fa0d7e3dSNick Piggin { 252fa0d7e3dSNick Piggin struct inode *inode = container_of(head, struct inode, i_rcu); 253fa0d7e3dSNick Piggin kfree(HOSTFS_I(inode)); 254fa0d7e3dSNick Piggin } 255fa0d7e3dSNick Piggin 2561da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2571da177e4SLinus Torvalds { 258fa0d7e3dSNick Piggin call_rcu(&inode->i_rcu, hostfs_i_callback); 2591da177e4SLinus Torvalds } 2601da177e4SLinus Torvalds 26134c80b1dSAl Viro static int hostfs_show_options(struct seq_file *seq, struct dentry *root) 262dd2cc4dfSMiklos Szeredi { 26334c80b1dSAl Viro const char *root_path = root->d_sb->s_fs_info; 264dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1; 265dd2cc4dfSMiklos Szeredi 266dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset) 267dd2cc4dfSMiklos Szeredi seq_printf(seq, ",%s", root_path + offset); 268dd2cc4dfSMiklos Szeredi 269dd2cc4dfSMiklos Szeredi return 0; 270dd2cc4dfSMiklos Szeredi } 271dd2cc4dfSMiklos Szeredi 272ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = { 2731da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode, 2741da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 275e971a6d7SAl Viro .evict_inode = hostfs_evict_inode, 2761da177e4SLinus Torvalds .statfs = hostfs_statfs, 277dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options, 2781da177e4SLinus Torvalds }; 2791da177e4SLinus Torvalds 2808e28bc7eSAl Viro int hostfs_readdir(struct file *file, struct dir_context *ctx) 2811da177e4SLinus Torvalds { 2821da177e4SLinus Torvalds void *dir; 2831da177e4SLinus Torvalds char *name; 2841da177e4SLinus Torvalds unsigned long long next, ino; 2851da177e4SLinus Torvalds int error, len; 2863ee6bd8eSGeert Uytterhoeven unsigned int type; 2871da177e4SLinus Torvalds 288c5322220SAl Viro name = dentry_name(file->f_path.dentry); 289f1adc05eSJeff Dike if (name == NULL) 290f1adc05eSJeff Dike return -ENOMEM; 2911da177e4SLinus Torvalds dir = open_dir(name, &error); 292e9193059SAl Viro __putname(name); 293f1adc05eSJeff Dike if (dir == NULL) 294f1adc05eSJeff Dike return -error; 2958e28bc7eSAl Viro next = ctx->pos; 2963ee6bd8eSGeert Uytterhoeven while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { 2978e28bc7eSAl Viro if (!dir_emit(ctx, name, len, ino, type)) 2988e28bc7eSAl Viro break; 2998e28bc7eSAl Viro ctx->pos = next; 3001da177e4SLinus Torvalds } 3011da177e4SLinus Torvalds close_dir(dir); 302f1adc05eSJeff Dike return 0; 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 3061da177e4SLinus Torvalds { 307f8ad850fSAl Viro static DEFINE_MUTEX(open_mutex); 3081da177e4SLinus Torvalds char *name; 309aeb5d727SAl Viro fmode_t mode = 0; 310f8ad850fSAl Viro int err; 311aeb5d727SAl Viro int r = 0, w = 0, fd; 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE); 3141da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode) 315f1adc05eSJeff Dike return 0; 3161da177e4SLinus Torvalds 317f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 3181da177e4SLinus Torvalds 319f8ad850fSAl Viro retry: 320f8ad850fSAl Viro if (mode & FMODE_READ) 3211da177e4SLinus Torvalds r = 1; 322f8ad850fSAl Viro if (mode & FMODE_WRITE) 3231da177e4SLinus Torvalds w = 1; 3241da177e4SLinus Torvalds if (w) 3251da177e4SLinus Torvalds r = 1; 3261da177e4SLinus Torvalds 327c5322220SAl Viro name = dentry_name(file->f_path.dentry); 3281da177e4SLinus Torvalds if (name == NULL) 329f1adc05eSJeff Dike return -ENOMEM; 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds fd = open_file(name, r, w, append); 332e9193059SAl Viro __putname(name); 333f1adc05eSJeff Dike if (fd < 0) 334f1adc05eSJeff Dike return fd; 335f8ad850fSAl Viro 336f8ad850fSAl Viro mutex_lock(&open_mutex); 337f8ad850fSAl Viro /* somebody else had handled it first? */ 338f8ad850fSAl Viro if ((mode & HOSTFS_I(ino)->mode) == mode) { 339f8ad850fSAl Viro mutex_unlock(&open_mutex); 340f8ad850fSAl Viro return 0; 341f8ad850fSAl Viro } 342f8ad850fSAl Viro if ((mode | HOSTFS_I(ino)->mode) != mode) { 343f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 344f8ad850fSAl Viro mutex_unlock(&open_mutex); 345f8ad850fSAl Viro close_file(&fd); 346f8ad850fSAl Viro goto retry; 347f8ad850fSAl Viro } 348f8ad850fSAl Viro if (HOSTFS_I(ino)->fd == -1) { 349f8ad850fSAl Viro HOSTFS_I(ino)->fd = fd; 350f8ad850fSAl Viro } else { 351f8ad850fSAl Viro err = replace_file(fd, HOSTFS_I(ino)->fd); 352f8ad850fSAl Viro close_file(&fd); 353f8ad850fSAl Viro if (err < 0) { 354f8ad850fSAl Viro mutex_unlock(&open_mutex); 355f8ad850fSAl Viro return err; 356f8ad850fSAl Viro } 357f8ad850fSAl Viro } 358f8ad850fSAl Viro HOSTFS_I(ino)->mode = mode; 359f8ad850fSAl Viro mutex_unlock(&open_mutex); 3601da177e4SLinus Torvalds 361f1adc05eSJeff Dike return 0; 3621da177e4SLinus Torvalds } 3631da177e4SLinus Torvalds 36465984ff9SRichard Weinberger static int hostfs_file_release(struct inode *inode, struct file *file) 36565984ff9SRichard Weinberger { 36665984ff9SRichard Weinberger filemap_write_and_wait(inode->i_mapping); 36765984ff9SRichard Weinberger 36865984ff9SRichard Weinberger return 0; 36965984ff9SRichard Weinberger } 37065984ff9SRichard Weinberger 37102c24a82SJosef Bacik int hostfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 3721da177e4SLinus Torvalds { 37302c24a82SJosef Bacik struct inode *inode = file->f_mapping->host; 37402c24a82SJosef Bacik int ret; 37502c24a82SJosef Bacik 37602c24a82SJosef Bacik ret = filemap_write_and_wait_range(inode->i_mapping, start, end); 37702c24a82SJosef Bacik if (ret) 37802c24a82SJosef Bacik return ret; 37902c24a82SJosef Bacik 38002c24a82SJosef Bacik mutex_lock(&inode->i_mutex); 38102c24a82SJosef Bacik ret = fsync_file(HOSTFS_I(inode)->fd, datasync); 38202c24a82SJosef Bacik mutex_unlock(&inode->i_mutex); 38302c24a82SJosef Bacik 38402c24a82SJosef Bacik return ret; 3851da177e4SLinus Torvalds } 3861da177e4SLinus Torvalds 3874b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3881da177e4SLinus Torvalds .llseek = generic_file_llseek, 389543ade1fSBadari Pulavarty .read = do_sync_read, 3905ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3911da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3921da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 393543ade1fSBadari Pulavarty .write = do_sync_write, 3941da177e4SLinus Torvalds .mmap = generic_file_mmap, 3951da177e4SLinus Torvalds .open = hostfs_file_open, 39665984ff9SRichard Weinberger .release = hostfs_file_release, 3971da177e4SLinus Torvalds .fsync = hostfs_fsync, 3981da177e4SLinus Torvalds }; 3991da177e4SLinus Torvalds 4004b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = { 4011da177e4SLinus Torvalds .llseek = generic_file_llseek, 4028e28bc7eSAl Viro .iterate = hostfs_readdir, 4031da177e4SLinus Torvalds .read = generic_read_dir, 4041da177e4SLinus Torvalds }; 4051da177e4SLinus Torvalds 4061da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 4071da177e4SLinus Torvalds { 4081da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4091da177e4SLinus Torvalds struct inode *inode = mapping->host; 4101da177e4SLinus Torvalds char *buffer; 4111da177e4SLinus Torvalds unsigned long long base; 4121da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 4131da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 4141da177e4SLinus Torvalds int err; 4151da177e4SLinus Torvalds 4161da177e4SLinus Torvalds if (page->index >= end_index) 4171da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds buffer = kmap(page); 4201da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4231da177e4SLinus Torvalds if (err != count) { 4241da177e4SLinus Torvalds ClearPageUptodate(page); 4251da177e4SLinus Torvalds goto out; 4261da177e4SLinus Torvalds } 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds if (base > inode->i_size) 4291da177e4SLinus Torvalds inode->i_size = base; 4301da177e4SLinus Torvalds 4311da177e4SLinus Torvalds if (PageError(page)) 4321da177e4SLinus Torvalds ClearPageError(page); 4331da177e4SLinus Torvalds err = 0; 4341da177e4SLinus Torvalds 4351da177e4SLinus Torvalds out: 4361da177e4SLinus Torvalds kunmap(page); 4371da177e4SLinus Torvalds 4381da177e4SLinus Torvalds unlock_page(page); 4391da177e4SLinus Torvalds return err; 4401da177e4SLinus Torvalds } 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4431da177e4SLinus Torvalds { 4441da177e4SLinus Torvalds char *buffer; 4451da177e4SLinus Torvalds long long start; 4461da177e4SLinus Torvalds int err = 0; 4471da177e4SLinus Torvalds 4481da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4491da177e4SLinus Torvalds buffer = kmap(page); 4501da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4511da177e4SLinus Torvalds PAGE_CACHE_SIZE); 45284b3db04SJeff Dike if (err < 0) 45384b3db04SJeff Dike goto out; 4541da177e4SLinus Torvalds 4551da177e4SLinus Torvalds memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); 4561da177e4SLinus Torvalds 4571da177e4SLinus Torvalds flush_dcache_page(page); 4581da177e4SLinus Torvalds SetPageUptodate(page); 4591da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 4601da177e4SLinus Torvalds err = 0; 4611da177e4SLinus Torvalds out: 4621da177e4SLinus Torvalds kunmap(page); 4631da177e4SLinus Torvalds unlock_page(page); 464f1adc05eSJeff Dike return err; 4651da177e4SLinus Torvalds } 4661da177e4SLinus Torvalds 467ae361ff4SNick Piggin int hostfs_write_begin(struct file *file, struct address_space *mapping, 468ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 469ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4701da177e4SLinus Torvalds { 471ae361ff4SNick Piggin pgoff_t index = pos >> PAGE_CACHE_SHIFT; 472ae361ff4SNick Piggin 47354566b2cSNick Piggin *pagep = grab_cache_page_write_begin(mapping, index, flags); 474ae361ff4SNick Piggin if (!*pagep) 475ae361ff4SNick Piggin return -ENOMEM; 476ae361ff4SNick Piggin return 0; 477ae361ff4SNick Piggin } 478ae361ff4SNick Piggin 479ae361ff4SNick Piggin int hostfs_write_end(struct file *file, struct address_space *mapping, 480ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 481ae361ff4SNick Piggin struct page *page, void *fsdata) 482ae361ff4SNick Piggin { 483ae361ff4SNick Piggin struct inode *inode = mapping->host; 484ae361ff4SNick Piggin void *buffer; 485ae361ff4SNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 4861da177e4SLinus Torvalds int err; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds buffer = kmap(page); 489ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4901da177e4SLinus Torvalds kunmap(page); 4911da177e4SLinus Torvalds 492ae361ff4SNick Piggin if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) 493ae361ff4SNick Piggin SetPageUptodate(page); 4941da177e4SLinus Torvalds 49584b3db04SJeff Dike /* 49684b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 497ae361ff4SNick Piggin * i_size against the last byte written. 498ae361ff4SNick Piggin */ 499ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 500ae361ff4SNick Piggin inode->i_size = pos; 501ae361ff4SNick Piggin unlock_page(page); 502ae361ff4SNick Piggin page_cache_release(page); 50330f04a4eSPaolo 'Blaisorblade' Giarrusso 504f1adc05eSJeff Dike return err; 5051da177e4SLinus Torvalds } 5061da177e4SLinus Torvalds 507f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 5081da177e4SLinus Torvalds .writepage = hostfs_writepage, 5091da177e4SLinus Torvalds .readpage = hostfs_readpage, 510ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 511ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 512ae361ff4SNick Piggin .write_end = hostfs_write_end, 5131da177e4SLinus Torvalds }; 5141da177e4SLinus Torvalds 5154754b825SAl Viro static int read_name(struct inode *ino, char *name) 5161da177e4SLinus Torvalds { 5174754b825SAl Viro dev_t rdev; 5184754b825SAl Viro struct hostfs_stat st; 5194754b825SAl Viro int err = stat_file(name, &st, -1); 5204754b825SAl Viro if (err) 5214754b825SAl Viro return err; 5221da177e4SLinus Torvalds 5231da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5244754b825SAl Viro rdev = MKDEV(st.maj, st.min); 5251da177e4SLinus Torvalds 5264754b825SAl Viro switch (st.mode & S_IFMT) { 5274754b825SAl Viro case S_IFLNK: 528d0352d3eSAl Viro ino->i_op = &hostfs_link_iops; 5294754b825SAl Viro break; 5304754b825SAl Viro case S_IFDIR: 5314754b825SAl Viro ino->i_op = &hostfs_dir_iops; 5324754b825SAl Viro ino->i_fop = &hostfs_dir_fops; 5334754b825SAl Viro break; 5344754b825SAl Viro case S_IFCHR: 5354754b825SAl Viro case S_IFBLK: 5364754b825SAl Viro case S_IFIFO: 5374754b825SAl Viro case S_IFSOCK: 5384754b825SAl Viro init_special_inode(ino, st.mode & S_IFMT, rdev); 5394754b825SAl Viro ino->i_op = &hostfs_iops; 5404754b825SAl Viro break; 5411da177e4SLinus Torvalds 5424754b825SAl Viro default: 5434754b825SAl Viro ino->i_op = &hostfs_iops; 5444754b825SAl Viro ino->i_fop = &hostfs_file_fops; 5454754b825SAl Viro ino->i_mapping->a_ops = &hostfs_aops; 5461da177e4SLinus Torvalds } 5474754b825SAl Viro 5484754b825SAl Viro ino->i_ino = st.ino; 5494754b825SAl Viro ino->i_mode = st.mode; 550bfe86848SMiklos Szeredi set_nlink(ino, st.nlink); 55129f82ae5SEric W. Biederman i_uid_write(ino, st.uid); 55229f82ae5SEric W. Biederman i_gid_write(ino, st.gid); 5534754b825SAl Viro ino->i_atime = st.atime; 5544754b825SAl Viro ino->i_mtime = st.mtime; 5554754b825SAl Viro ino->i_ctime = st.ctime; 5564754b825SAl Viro ino->i_size = st.size; 5574754b825SAl Viro ino->i_blocks = st.blocks; 5584754b825SAl Viro return 0; 5591da177e4SLinus Torvalds } 5601da177e4SLinus Torvalds 5614acdaf27SAl Viro int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, 562ebfc3b49SAl Viro bool excl) 5631da177e4SLinus Torvalds { 5641da177e4SLinus Torvalds struct inode *inode; 5651da177e4SLinus Torvalds char *name; 5661da177e4SLinus Torvalds int error, fd; 5671da177e4SLinus Torvalds 5680a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 5690a370e5dSDavid Howells if (IS_ERR(inode)) { 5700a370e5dSDavid Howells error = PTR_ERR(inode); 57184b3db04SJeff Dike goto out; 5720a370e5dSDavid Howells } 5731da177e4SLinus Torvalds 5741da177e4SLinus Torvalds error = -ENOMEM; 575c5322220SAl Viro name = dentry_name(dentry); 5761da177e4SLinus Torvalds if (name == NULL) 5771da177e4SLinus Torvalds goto out_put; 5781da177e4SLinus Torvalds 5791da177e4SLinus Torvalds fd = file_create(name, 5801da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 5811da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 5821da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 5834754b825SAl Viro if (fd < 0) 5841da177e4SLinus Torvalds error = fd; 5854754b825SAl Viro else 5865e2df28cSAl Viro error = read_name(inode, name); 5871da177e4SLinus Torvalds 588e9193059SAl Viro __putname(name); 5891da177e4SLinus Torvalds if (error) 5901da177e4SLinus Torvalds goto out_put; 5911da177e4SLinus Torvalds 5921da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5931da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 5941da177e4SLinus Torvalds d_instantiate(dentry, inode); 595f1adc05eSJeff Dike return 0; 5961da177e4SLinus Torvalds 5971da177e4SLinus Torvalds out_put: 5981da177e4SLinus Torvalds iput(inode); 5991da177e4SLinus Torvalds out: 600f1adc05eSJeff Dike return error; 6011da177e4SLinus Torvalds } 6021da177e4SLinus Torvalds 6031da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 60400cd8dd3SAl Viro unsigned int flags) 6051da177e4SLinus Torvalds { 6061da177e4SLinus Torvalds struct inode *inode; 6071da177e4SLinus Torvalds char *name; 6081da177e4SLinus Torvalds int err; 6091da177e4SLinus Torvalds 6100a370e5dSDavid Howells inode = hostfs_iget(ino->i_sb); 6110a370e5dSDavid Howells if (IS_ERR(inode)) { 6120a370e5dSDavid Howells err = PTR_ERR(inode); 6131da177e4SLinus Torvalds goto out; 6140a370e5dSDavid Howells } 6151da177e4SLinus Torvalds 6161da177e4SLinus Torvalds err = -ENOMEM; 617c5322220SAl Viro name = dentry_name(dentry); 6181da177e4SLinus Torvalds if (name == NULL) 6191da177e4SLinus Torvalds goto out_put; 6201da177e4SLinus Torvalds 6211da177e4SLinus Torvalds err = read_name(inode, name); 6225e2df28cSAl Viro 623e9193059SAl Viro __putname(name); 6241da177e4SLinus Torvalds if (err == -ENOENT) { 6251da177e4SLinus Torvalds iput(inode); 6261da177e4SLinus Torvalds inode = NULL; 6271da177e4SLinus Torvalds } 6281da177e4SLinus Torvalds else if (err) 6291da177e4SLinus Torvalds goto out_put; 6301da177e4SLinus Torvalds 6311da177e4SLinus Torvalds d_add(dentry, inode); 632f1adc05eSJeff Dike return NULL; 6331da177e4SLinus Torvalds 6341da177e4SLinus Torvalds out_put: 6351da177e4SLinus Torvalds iput(inode); 6361da177e4SLinus Torvalds out: 637f1adc05eSJeff Dike return ERR_PTR(err); 6381da177e4SLinus Torvalds } 6391da177e4SLinus Torvalds 6401da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6411da177e4SLinus Torvalds { 6421da177e4SLinus Torvalds char *from_name, *to_name; 6431da177e4SLinus Torvalds int err; 6441da177e4SLinus Torvalds 645c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 646f1adc05eSJeff Dike return -ENOMEM; 647c5322220SAl Viro to_name = dentry_name(to); 6481da177e4SLinus Torvalds if (to_name == NULL) { 649e9193059SAl Viro __putname(from_name); 650f1adc05eSJeff Dike return -ENOMEM; 6511da177e4SLinus Torvalds } 6521da177e4SLinus Torvalds err = link_file(to_name, from_name); 653e9193059SAl Viro __putname(from_name); 654e9193059SAl Viro __putname(to_name); 655f1adc05eSJeff Dike return err; 6561da177e4SLinus Torvalds } 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6591da177e4SLinus Torvalds { 6601da177e4SLinus Torvalds char *file; 6611da177e4SLinus Torvalds int err; 6621da177e4SLinus Torvalds 6631da177e4SLinus Torvalds if (append) 664f1adc05eSJeff Dike return -EPERM; 6651da177e4SLinus Torvalds 666f8d7e187SAl Viro if ((file = dentry_name(dentry)) == NULL) 667f8d7e187SAl Viro return -ENOMEM; 668f8d7e187SAl Viro 6691da177e4SLinus Torvalds err = unlink_file(file); 670e9193059SAl Viro __putname(file); 671f1adc05eSJeff Dike return err; 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds 6741da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 6751da177e4SLinus Torvalds { 6761da177e4SLinus Torvalds char *file; 6771da177e4SLinus Torvalds int err; 6781da177e4SLinus Torvalds 679c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 680f1adc05eSJeff Dike return -ENOMEM; 6811da177e4SLinus Torvalds err = make_symlink(file, to); 682e9193059SAl Viro __putname(file); 683f1adc05eSJeff Dike return err; 6841da177e4SLinus Torvalds } 6851da177e4SLinus Torvalds 68618bb1db3SAl Viro int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) 6871da177e4SLinus Torvalds { 6881da177e4SLinus Torvalds char *file; 6891da177e4SLinus Torvalds int err; 6901da177e4SLinus Torvalds 691c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 692f1adc05eSJeff Dike return -ENOMEM; 6931da177e4SLinus Torvalds err = do_mkdir(file, mode); 694e9193059SAl Viro __putname(file); 695f1adc05eSJeff Dike return err; 6961da177e4SLinus Torvalds } 6971da177e4SLinus Torvalds 6981da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 6991da177e4SLinus Torvalds { 7001da177e4SLinus Torvalds char *file; 7011da177e4SLinus Torvalds int err; 7021da177e4SLinus Torvalds 703c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 704f1adc05eSJeff Dike return -ENOMEM; 7051da177e4SLinus Torvalds err = do_rmdir(file); 706e9193059SAl Viro __putname(file); 707f1adc05eSJeff Dike return err; 7081da177e4SLinus Torvalds } 7091da177e4SLinus Torvalds 7101a67aafbSAl Viro static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) 7111da177e4SLinus Torvalds { 7121da177e4SLinus Torvalds struct inode *inode; 7131da177e4SLinus Torvalds char *name; 7140a370e5dSDavid Howells int err; 7151da177e4SLinus Torvalds 7160a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 7170a370e5dSDavid Howells if (IS_ERR(inode)) { 7180a370e5dSDavid Howells err = PTR_ERR(inode); 7191da177e4SLinus Torvalds goto out; 7200a370e5dSDavid Howells } 7211da177e4SLinus Torvalds 7221da177e4SLinus Torvalds err = -ENOMEM; 723c5322220SAl Viro name = dentry_name(dentry); 7241da177e4SLinus Torvalds if (name == NULL) 7251da177e4SLinus Torvalds goto out_put; 7261da177e4SLinus Torvalds 7271da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 72888f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 729e9193059SAl Viro if (!err) 7301da177e4SLinus Torvalds goto out_free; 7311da177e4SLinus Torvalds 7321da177e4SLinus Torvalds err = read_name(inode, name); 733e9193059SAl Viro __putname(name); 7345e2df28cSAl Viro if (err) 7355e2df28cSAl Viro goto out_put; 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: 743e9193059SAl Viro __putname(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 756c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 757f1adc05eSJeff Dike return -ENOMEM; 758c5322220SAl Viro if ((to_name = dentry_name(to)) == NULL) { 759e9193059SAl Viro __putname(from_name); 760f1adc05eSJeff Dike return -ENOMEM; 7611da177e4SLinus Torvalds } 7621da177e4SLinus Torvalds err = rename_file(from_name, to_name); 763e9193059SAl Viro __putname(from_name); 764e9193059SAl Viro __putname(to_name); 765f1adc05eSJeff Dike return err; 7661da177e4SLinus Torvalds } 7671da177e4SLinus Torvalds 76810556cb2SAl 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 77310556cb2SAl Viro if (desired & MAY_NOT_BLOCK) 774b74c79e9SNick Piggin return -ECHILD; 775b74c79e9SNick Piggin 7761da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7771da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7781da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 779c5322220SAl Viro name = inode_name(ino); 780f1adc05eSJeff Dike if (name == NULL) 781f1adc05eSJeff Dike return -ENOMEM; 7821da177e4SLinus Torvalds 7831da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 7841da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 7851da177e4SLinus Torvalds err = 0; 7861da177e4SLinus Torvalds else 7871da177e4SLinus Torvalds err = access_file(name, r, w, x); 788e9193059SAl Viro __putname(name); 7891da177e4SLinus Torvalds if (!err) 7902830ba7fSAl Viro err = generic_permission(ino, desired); 7911da177e4SLinus Torvalds return err; 7921da177e4SLinus Torvalds } 7931da177e4SLinus Torvalds 7941da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 7951da177e4SLinus Torvalds { 7961025774cSChristoph Hellwig struct inode *inode = dentry->d_inode; 7971da177e4SLinus Torvalds struct hostfs_iattr attrs; 7981da177e4SLinus Torvalds char *name; 7991da177e4SLinus Torvalds int err; 8001da177e4SLinus Torvalds 8011025774cSChristoph Hellwig int fd = HOSTFS_I(inode)->fd; 8025822b7faSAlberto Bertogli 8031025774cSChristoph Hellwig err = inode_change_ok(inode, attr); 8041da177e4SLinus Torvalds if (err) 8051da177e4SLinus Torvalds return err; 8061da177e4SLinus Torvalds 8071da177e4SLinus Torvalds if (append) 8081da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8091da177e4SLinus Torvalds 8101da177e4SLinus Torvalds attrs.ia_valid = 0; 8111da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) { 8121da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8131da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8141da177e4SLinus Torvalds } 8151da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) { 8161da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 81729f82ae5SEric W. Biederman attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); 8181da177e4SLinus Torvalds } 8191da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8201da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 82129f82ae5SEric W. Biederman attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); 8221da177e4SLinus Torvalds } 8231da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) { 8241da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8251da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8261da177e4SLinus Torvalds } 8271da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) { 8281da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8291da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8301da177e4SLinus Torvalds } 8311da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8321da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8331da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8341da177e4SLinus Torvalds } 8351da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8361da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8371da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 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 8571025774cSChristoph Hellwig setattr_copy(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, 8761da177e4SLinus Torvalds .rename = hostfs_rename, 8771da177e4SLinus Torvalds .permission = hostfs_permission, 8781da177e4SLinus Torvalds .setattr = hostfs_setattr, 8791da177e4SLinus Torvalds }; 8801da177e4SLinus Torvalds 881d0352d3eSAl Viro static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) 8821da177e4SLinus Torvalds { 883d0352d3eSAl Viro char *link = __getname(); 884d0352d3eSAl Viro if (link) { 885d0352d3eSAl Viro char *path = dentry_name(dentry); 886d0352d3eSAl Viro int err = -ENOMEM; 887d0352d3eSAl Viro if (path) { 8883b6036d1SAl Viro err = hostfs_do_readlink(path, link, PATH_MAX); 889d0352d3eSAl Viro if (err == PATH_MAX) 8901da177e4SLinus Torvalds err = -E2BIG; 891e9193059SAl Viro __putname(path); 8921da177e4SLinus Torvalds } 893d0352d3eSAl Viro if (err < 0) { 894d0352d3eSAl Viro __putname(link); 895d0352d3eSAl Viro link = ERR_PTR(err); 896d0352d3eSAl Viro } 897d0352d3eSAl Viro } else { 898d0352d3eSAl Viro link = ERR_PTR(-ENOMEM); 8991da177e4SLinus Torvalds } 9001da177e4SLinus Torvalds 901d0352d3eSAl Viro nd_set_link(nd, link); 902d0352d3eSAl Viro return NULL; 903d0352d3eSAl Viro } 904d0352d3eSAl Viro 905d0352d3eSAl Viro static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) 906d0352d3eSAl Viro { 907d0352d3eSAl Viro char *s = nd_get_link(nd); 908d0352d3eSAl Viro if (!IS_ERR(s)) 909d0352d3eSAl Viro __putname(s); 910d0352d3eSAl Viro } 911d0352d3eSAl Viro 912d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops = { 913d0352d3eSAl Viro .readlink = generic_readlink, 914d0352d3eSAl Viro .follow_link = hostfs_follow_link, 915d0352d3eSAl Viro .put_link = hostfs_put_link, 9161da177e4SLinus Torvalds }; 9171da177e4SLinus Torvalds 9181da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9191da177e4SLinus Torvalds { 9201da177e4SLinus Torvalds struct inode *root_inode; 92175e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9221da177e4SLinus Torvalds int err; 9231da177e4SLinus Torvalds 9241da177e4SLinus Torvalds sb->s_blocksize = 1024; 9251da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9261da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9271da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 928f772c4a6SAl Viro sb->s_d_op = &hostfs_dentry_ops; 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 9474754b825SAl Viro err = read_name(root_inode, host_root_path); 9484754b825SAl Viro if (err) 9494754b825SAl Viro goto out_put; 95052b209f7SAl Viro 9514754b825SAl Viro if (S_ISLNK(root_inode->i_mode)) { 95252b209f7SAl Viro char *name = follow_link(host_root_path); 95352b209f7SAl Viro if (IS_ERR(name)) 95452b209f7SAl Viro err = PTR_ERR(name); 95552b209f7SAl Viro else 95652b209f7SAl Viro err = read_name(root_inode, name); 95752b209f7SAl Viro kfree(name); 9581da177e4SLinus Torvalds if (err) 9591da177e4SLinus Torvalds goto out_put; 9604754b825SAl Viro } 9611da177e4SLinus Torvalds 9621da177e4SLinus Torvalds err = -ENOMEM; 96348fde701SAl Viro sb->s_root = d_make_root(root_inode); 9641da177e4SLinus Torvalds if (sb->s_root == NULL) 96548fde701SAl Viro goto out; 9661da177e4SLinus Torvalds 967f1adc05eSJeff Dike return 0; 9681da177e4SLinus Torvalds 9691da177e4SLinus Torvalds out_put: 9701da177e4SLinus Torvalds iput(root_inode); 9711da177e4SLinus Torvalds out: 972f1adc05eSJeff Dike return err; 9731da177e4SLinus Torvalds } 9741da177e4SLinus Torvalds 9753c26ff6eSAl Viro static struct dentry *hostfs_read_sb(struct file_system_type *type, 9761da177e4SLinus Torvalds int flags, const char *dev_name, 9773c26ff6eSAl Viro void *data) 9781da177e4SLinus Torvalds { 9793c26ff6eSAl Viro return mount_nodev(type, flags, data, hostfs_fill_sb_common); 9801da177e4SLinus Torvalds } 9811da177e4SLinus Torvalds 982601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s) 983601d2c38SAl Viro { 984601d2c38SAl Viro kill_anon_super(s); 985601d2c38SAl Viro kfree(s->s_fs_info); 986601d2c38SAl Viro } 987601d2c38SAl Viro 9881da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 9891da177e4SLinus Torvalds .owner = THIS_MODULE, 9901da177e4SLinus Torvalds .name = "hostfs", 9913c26ff6eSAl Viro .mount = hostfs_read_sb, 992601d2c38SAl Viro .kill_sb = hostfs_kill_sb, 9931da177e4SLinus Torvalds .fs_flags = 0, 9941da177e4SLinus Torvalds }; 9953e64fe5bSEric W. Biederman MODULE_ALIAS_FS("hostfs"); 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