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 361da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */ 37a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = ""; 381da177e4SLinus Torvalds static int append = 0; 391da177e4SLinus Torvalds 4092e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops; 4192e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops; 42d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops; 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds #ifndef MODULE 451da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add) 461da177e4SLinus Torvalds { 471da177e4SLinus Torvalds char *ptr; 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds ptr = strchr(options, ','); 501da177e4SLinus Torvalds if (ptr != NULL) 511da177e4SLinus Torvalds *ptr++ = '\0'; 521da177e4SLinus Torvalds if (*options != '\0') 531da177e4SLinus Torvalds root_ino = options; 541da177e4SLinus Torvalds 551da177e4SLinus Torvalds options = ptr; 561da177e4SLinus Torvalds while (options) { 571da177e4SLinus Torvalds ptr = strchr(options, ','); 581da177e4SLinus Torvalds if (ptr != NULL) 591da177e4SLinus Torvalds *ptr++ = '\0'; 601da177e4SLinus Torvalds if (*options != '\0') { 611da177e4SLinus Torvalds if (!strcmp(options, "append")) 621da177e4SLinus Torvalds append = 1; 631da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n", 641da177e4SLinus Torvalds options); 651da177e4SLinus Torvalds } 661da177e4SLinus Torvalds options = ptr; 671da177e4SLinus Torvalds } 68f1adc05eSJeff Dike return 0; 691da177e4SLinus Torvalds } 701da177e4SLinus Torvalds 711da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args, 721da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n" 731da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n" 741da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n" 751da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n" 761da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n" 771da177e4SLinus Torvalds " it.\n" 781da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n" 791da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n" 801da177e4SLinus Torvalds ); 811da177e4SLinus Torvalds #endif 821da177e4SLinus Torvalds 83e9193059SAl Viro static char *__dentry_name(struct dentry *dentry, char *name) 84e9193059SAl Viro { 85ec2447c2SNick Piggin char *p = dentry_path_raw(dentry, name, PATH_MAX); 86e9193059SAl Viro char *root; 87e9193059SAl Viro size_t len; 88e9193059SAl Viro 89e9193059SAl Viro root = dentry->d_sb->s_fs_info; 90e9193059SAl Viro len = strlen(root); 91e9193059SAl Viro if (IS_ERR(p)) { 92e9193059SAl Viro __putname(name); 93e9193059SAl Viro return NULL; 94e9193059SAl Viro } 95850a496fSAl Viro strlcpy(name, root, PATH_MAX); 96e9193059SAl Viro if (len > p - name) { 97e9193059SAl Viro __putname(name); 98e9193059SAl Viro return NULL; 99e9193059SAl Viro } 100e9193059SAl Viro if (p > name + len) { 101e9193059SAl Viro char *s = name + len; 102e9193059SAl Viro while ((*s++ = *p++) != '\0') 103e9193059SAl Viro ; 104e9193059SAl Viro } 105e9193059SAl Viro return name; 106e9193059SAl Viro } 107e9193059SAl Viro 108c5322220SAl Viro static char *dentry_name(struct dentry *dentry) 1091da177e4SLinus Torvalds { 110e9193059SAl Viro char *name = __getname(); 111e9193059SAl Viro if (!name) 112f1adc05eSJeff Dike return NULL; 1131da177e4SLinus Torvalds 1149dcc5e8aSJames Hogan return __dentry_name(dentry, name); 1151da177e4SLinus Torvalds } 1161da177e4SLinus Torvalds 117c5322220SAl Viro static char *inode_name(struct inode *ino) 1181da177e4SLinus Torvalds { 1191da177e4SLinus Torvalds struct dentry *dentry; 120ec2447c2SNick Piggin char *name; 121ec2447c2SNick Piggin 122ec2447c2SNick Piggin dentry = d_find_alias(ino); 123ec2447c2SNick Piggin if (!dentry) 124e9193059SAl Viro return NULL; 1251da177e4SLinus Torvalds 126ec2447c2SNick Piggin name = dentry_name(dentry); 127ec2447c2SNick Piggin 128ec2447c2SNick Piggin dput(dentry); 129ec2447c2SNick Piggin 130ec2447c2SNick Piggin return name; 1311da177e4SLinus Torvalds } 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds static char *follow_link(char *link) 1341da177e4SLinus Torvalds { 1351da177e4SLinus Torvalds int len, n; 1361da177e4SLinus Torvalds char *name, *resolved, *end; 1371da177e4SLinus Torvalds 1381da177e4SLinus Torvalds len = 64; 1391da177e4SLinus Torvalds while (1) { 1401da177e4SLinus Torvalds n = -ENOMEM; 1411da177e4SLinus Torvalds name = kmalloc(len, GFP_KERNEL); 1421da177e4SLinus Torvalds if (name == NULL) 1431da177e4SLinus Torvalds goto out; 1441da177e4SLinus Torvalds 145ea7e743eSWANG Cong n = hostfs_do_readlink(link, name, len); 1461da177e4SLinus Torvalds if (n < len) 1471da177e4SLinus Torvalds break; 1481da177e4SLinus Torvalds len *= 2; 1491da177e4SLinus Torvalds kfree(name); 1501da177e4SLinus Torvalds } 1511da177e4SLinus Torvalds if (n < 0) 1521da177e4SLinus Torvalds goto out_free; 1531da177e4SLinus Torvalds 1541da177e4SLinus Torvalds if (*name == '/') 155f1adc05eSJeff Dike return name; 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds end = strrchr(link, '/'); 1581da177e4SLinus Torvalds if (end == NULL) 159f1adc05eSJeff Dike return name; 1601da177e4SLinus Torvalds 1611da177e4SLinus Torvalds *(end + 1) = '\0'; 1621da177e4SLinus Torvalds len = strlen(link) + strlen(name) + 1; 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds resolved = kmalloc(len, GFP_KERNEL); 1651da177e4SLinus Torvalds if (resolved == NULL) { 1661da177e4SLinus Torvalds n = -ENOMEM; 1671da177e4SLinus Torvalds goto out_free; 1681da177e4SLinus Torvalds } 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds sprintf(resolved, "%s%s", link, name); 1711da177e4SLinus Torvalds kfree(name); 1721da177e4SLinus Torvalds kfree(link); 173f1adc05eSJeff Dike return resolved; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds out_free: 1761da177e4SLinus Torvalds kfree(name); 1771da177e4SLinus Torvalds out: 178f1adc05eSJeff Dike return ERR_PTR(n); 1791da177e4SLinus Torvalds } 1801da177e4SLinus Torvalds 1810a370e5dSDavid Howells static struct inode *hostfs_iget(struct super_block *sb) 1820a370e5dSDavid Howells { 18352b209f7SAl Viro struct inode *inode = new_inode(sb); 1840a370e5dSDavid Howells if (!inode) 1850a370e5dSDavid Howells return ERR_PTR(-ENOMEM); 1860a370e5dSDavid Howells return inode; 1870a370e5dSDavid Howells } 1880a370e5dSDavid Howells 189726c3342SDavid Howells int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) 1901da177e4SLinus Torvalds { 19184b3db04SJeff Dike /* 19284b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel 1931da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields, 1941da177e4SLinus Torvalds * so we convert them here 1951da177e4SLinus Torvalds */ 1961da177e4SLinus Torvalds int err; 1971da177e4SLinus Torvalds long long f_blocks; 1981da177e4SLinus Torvalds long long f_bfree; 1991da177e4SLinus Torvalds long long f_bavail; 2001da177e4SLinus Torvalds long long f_files; 2011da177e4SLinus Torvalds long long f_ffree; 2021da177e4SLinus Torvalds 203601d2c38SAl Viro err = do_statfs(dentry->d_sb->s_fs_info, 2041da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, 2051da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), 2061b627d57SRichard Weinberger &sf->f_namelen); 207f1adc05eSJeff Dike if (err) 208f1adc05eSJeff Dike return err; 2091da177e4SLinus Torvalds sf->f_blocks = f_blocks; 2101da177e4SLinus Torvalds sf->f_bfree = f_bfree; 2111da177e4SLinus Torvalds sf->f_bavail = f_bavail; 2121da177e4SLinus Torvalds sf->f_files = f_files; 2131da177e4SLinus Torvalds sf->f_ffree = f_ffree; 2141da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC; 215f1adc05eSJeff Dike return 0; 2161da177e4SLinus Torvalds } 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb) 2191da177e4SLinus Torvalds { 2201da177e4SLinus Torvalds struct hostfs_inode_info *hi; 2211da177e4SLinus Torvalds 222371fdab1SJames Hogan hi = kmalloc(sizeof(*hi), GFP_KERNEL); 2231da177e4SLinus Torvalds if (hi == NULL) 224f1adc05eSJeff Dike return NULL; 225601d2c38SAl Viro hi->fd = -1; 226371fdab1SJames Hogan hi->mode = 0; 2271da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode); 228f1adc05eSJeff Dike return &hi->vfs_inode; 2291da177e4SLinus Torvalds } 2301da177e4SLinus Torvalds 231e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode) 2321da177e4SLinus Torvalds { 233fef26658SMark Fasheh truncate_inode_pages(&inode->i_data, 0); 234dbd5768fSJan Kara clear_inode(inode); 2351da177e4SLinus Torvalds if (HOSTFS_I(inode)->fd != -1) { 2361da177e4SLinus Torvalds close_file(&HOSTFS_I(inode)->fd); 2371da177e4SLinus Torvalds HOSTFS_I(inode)->fd = -1; 2381da177e4SLinus Torvalds } 2391da177e4SLinus Torvalds } 2401da177e4SLinus Torvalds 241fa0d7e3dSNick Piggin static void hostfs_i_callback(struct rcu_head *head) 242fa0d7e3dSNick Piggin { 243fa0d7e3dSNick Piggin struct inode *inode = container_of(head, struct inode, i_rcu); 244fa0d7e3dSNick Piggin kfree(HOSTFS_I(inode)); 245fa0d7e3dSNick Piggin } 246fa0d7e3dSNick Piggin 2471da177e4SLinus Torvalds static void hostfs_destroy_inode(struct inode *inode) 2481da177e4SLinus Torvalds { 249fa0d7e3dSNick Piggin call_rcu(&inode->i_rcu, hostfs_i_callback); 2501da177e4SLinus Torvalds } 2511da177e4SLinus Torvalds 25234c80b1dSAl Viro static int hostfs_show_options(struct seq_file *seq, struct dentry *root) 253dd2cc4dfSMiklos Szeredi { 25434c80b1dSAl Viro const char *root_path = root->d_sb->s_fs_info; 255dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1; 256dd2cc4dfSMiklos Szeredi 257dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset) 258dd2cc4dfSMiklos Szeredi seq_printf(seq, ",%s", root_path + offset); 259dd2cc4dfSMiklos Szeredi 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, 2651da177e4SLinus Torvalds .destroy_inode = hostfs_destroy_inode, 266e971a6d7SAl Viro .evict_inode = hostfs_evict_inode, 2671da177e4SLinus Torvalds .statfs = hostfs_statfs, 268dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options, 2691da177e4SLinus Torvalds }; 2701da177e4SLinus Torvalds 2718e28bc7eSAl Viro 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; 2873ee6bd8eSGeert Uytterhoeven while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { 2888e28bc7eSAl Viro if (!dir_emit(ctx, name, len, ino, type)) 2898e28bc7eSAl Viro break; 2908e28bc7eSAl Viro ctx->pos = next; 2911da177e4SLinus Torvalds } 2921da177e4SLinus Torvalds close_dir(dir); 293f1adc05eSJeff Dike return 0; 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds int hostfs_file_open(struct inode *ino, struct file *file) 2971da177e4SLinus Torvalds { 298f8ad850fSAl Viro static DEFINE_MUTEX(open_mutex); 2991da177e4SLinus Torvalds char *name; 300aeb5d727SAl Viro fmode_t mode = 0; 301f8ad850fSAl Viro int err; 302aeb5d727SAl Viro int r = 0, w = 0, 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: 311f8ad850fSAl Viro if (mode & FMODE_READ) 3121da177e4SLinus Torvalds r = 1; 313f8ad850fSAl Viro if (mode & FMODE_WRITE) 3141da177e4SLinus Torvalds w = 1; 3151da177e4SLinus Torvalds if (w) 3161da177e4SLinus Torvalds r = 1; 3171da177e4SLinus Torvalds 318c5322220SAl Viro name = dentry_name(file->f_path.dentry); 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 327f8ad850fSAl Viro mutex_lock(&open_mutex); 328f8ad850fSAl Viro /* somebody else had handled it first? */ 329f8ad850fSAl Viro if ((mode & HOSTFS_I(ino)->mode) == mode) { 330f8ad850fSAl Viro mutex_unlock(&open_mutex); 331f8ad850fSAl Viro return 0; 332f8ad850fSAl Viro } 333f8ad850fSAl Viro if ((mode | HOSTFS_I(ino)->mode) != mode) { 334f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode; 335f8ad850fSAl Viro mutex_unlock(&open_mutex); 336f8ad850fSAl Viro close_file(&fd); 337f8ad850fSAl Viro goto retry; 338f8ad850fSAl Viro } 339f8ad850fSAl Viro if (HOSTFS_I(ino)->fd == -1) { 340f8ad850fSAl Viro HOSTFS_I(ino)->fd = fd; 341f8ad850fSAl Viro } else { 342f8ad850fSAl Viro err = replace_file(fd, HOSTFS_I(ino)->fd); 343f8ad850fSAl Viro close_file(&fd); 344f8ad850fSAl Viro if (err < 0) { 345f8ad850fSAl Viro mutex_unlock(&open_mutex); 346f8ad850fSAl Viro return err; 347f8ad850fSAl Viro } 348f8ad850fSAl Viro } 349f8ad850fSAl Viro HOSTFS_I(ino)->mode = mode; 350f8ad850fSAl Viro mutex_unlock(&open_mutex); 3511da177e4SLinus Torvalds 352f1adc05eSJeff Dike return 0; 3531da177e4SLinus Torvalds } 3541da177e4SLinus Torvalds 35565984ff9SRichard Weinberger static int hostfs_file_release(struct inode *inode, struct file *file) 35665984ff9SRichard Weinberger { 35765984ff9SRichard Weinberger filemap_write_and_wait(inode->i_mapping); 35865984ff9SRichard Weinberger 35965984ff9SRichard Weinberger return 0; 36065984ff9SRichard Weinberger } 36165984ff9SRichard Weinberger 36202c24a82SJosef Bacik int hostfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 3631da177e4SLinus Torvalds { 36402c24a82SJosef Bacik struct inode *inode = file->f_mapping->host; 36502c24a82SJosef Bacik int ret; 36602c24a82SJosef Bacik 36702c24a82SJosef Bacik ret = filemap_write_and_wait_range(inode->i_mapping, start, end); 36802c24a82SJosef Bacik if (ret) 36902c24a82SJosef Bacik return ret; 37002c24a82SJosef Bacik 37102c24a82SJosef Bacik mutex_lock(&inode->i_mutex); 37202c24a82SJosef Bacik ret = fsync_file(HOSTFS_I(inode)->fd, datasync); 37302c24a82SJosef Bacik mutex_unlock(&inode->i_mutex); 37402c24a82SJosef Bacik 37502c24a82SJosef Bacik return ret; 3761da177e4SLinus Torvalds } 3771da177e4SLinus Torvalds 3784b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = { 3791da177e4SLinus Torvalds .llseek = generic_file_llseek, 380543ade1fSBadari Pulavarty .read = do_sync_read, 3815ffc4ef4SJens Axboe .splice_read = generic_file_splice_read, 3821da177e4SLinus Torvalds .aio_read = generic_file_aio_read, 3831da177e4SLinus Torvalds .aio_write = generic_file_aio_write, 384543ade1fSBadari Pulavarty .write = do_sync_write, 3851da177e4SLinus Torvalds .mmap = generic_file_mmap, 3861da177e4SLinus Torvalds .open = hostfs_file_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, 3938e28bc7eSAl Viro .iterate = hostfs_readdir, 3941da177e4SLinus Torvalds .read = generic_read_dir, 3951da177e4SLinus Torvalds }; 3961da177e4SLinus Torvalds 3971da177e4SLinus Torvalds int hostfs_writepage(struct page *page, struct writeback_control *wbc) 3981da177e4SLinus Torvalds { 3991da177e4SLinus Torvalds struct address_space *mapping = page->mapping; 4001da177e4SLinus Torvalds struct inode *inode = mapping->host; 4011da177e4SLinus Torvalds char *buffer; 4021da177e4SLinus Torvalds unsigned long long base; 4031da177e4SLinus Torvalds int count = PAGE_CACHE_SIZE; 4041da177e4SLinus Torvalds int end_index = inode->i_size >> PAGE_CACHE_SHIFT; 4051da177e4SLinus Torvalds int err; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds if (page->index >= end_index) 4081da177e4SLinus Torvalds count = inode->i_size & (PAGE_CACHE_SIZE-1); 4091da177e4SLinus Torvalds 4101da177e4SLinus Torvalds buffer = kmap(page); 4111da177e4SLinus Torvalds base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; 4121da177e4SLinus Torvalds 4131da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); 4141da177e4SLinus Torvalds if (err != count) { 4151da177e4SLinus Torvalds ClearPageUptodate(page); 4161da177e4SLinus Torvalds goto out; 4171da177e4SLinus Torvalds } 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds if (base > inode->i_size) 4201da177e4SLinus Torvalds inode->i_size = base; 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds if (PageError(page)) 4231da177e4SLinus Torvalds ClearPageError(page); 4241da177e4SLinus Torvalds err = 0; 4251da177e4SLinus Torvalds 4261da177e4SLinus Torvalds out: 4271da177e4SLinus Torvalds kunmap(page); 4281da177e4SLinus Torvalds 4291da177e4SLinus Torvalds unlock_page(page); 4301da177e4SLinus Torvalds return err; 4311da177e4SLinus Torvalds } 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds int hostfs_readpage(struct file *file, struct page *page) 4341da177e4SLinus Torvalds { 4351da177e4SLinus Torvalds char *buffer; 4361da177e4SLinus Torvalds long long start; 4371da177e4SLinus Torvalds int err = 0; 4381da177e4SLinus Torvalds 4391da177e4SLinus Torvalds start = (long long) page->index << PAGE_CACHE_SHIFT; 4401da177e4SLinus Torvalds buffer = kmap(page); 4411da177e4SLinus Torvalds err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, 4421da177e4SLinus Torvalds PAGE_CACHE_SIZE); 44384b3db04SJeff Dike if (err < 0) 44484b3db04SJeff Dike goto out; 4451da177e4SLinus Torvalds 4461da177e4SLinus Torvalds memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); 4471da177e4SLinus Torvalds 4481da177e4SLinus Torvalds flush_dcache_page(page); 4491da177e4SLinus Torvalds SetPageUptodate(page); 4501da177e4SLinus Torvalds if (PageError(page)) ClearPageError(page); 4511da177e4SLinus Torvalds err = 0; 4521da177e4SLinus Torvalds out: 4531da177e4SLinus Torvalds kunmap(page); 4541da177e4SLinus Torvalds unlock_page(page); 455f1adc05eSJeff Dike return err; 4561da177e4SLinus Torvalds } 4571da177e4SLinus Torvalds 458ae361ff4SNick Piggin int hostfs_write_begin(struct file *file, struct address_space *mapping, 459ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned flags, 460ae361ff4SNick Piggin struct page **pagep, void **fsdata) 4611da177e4SLinus Torvalds { 462ae361ff4SNick Piggin pgoff_t index = pos >> PAGE_CACHE_SHIFT; 463ae361ff4SNick Piggin 46454566b2cSNick Piggin *pagep = grab_cache_page_write_begin(mapping, index, flags); 465ae361ff4SNick Piggin if (!*pagep) 466ae361ff4SNick Piggin return -ENOMEM; 467ae361ff4SNick Piggin return 0; 468ae361ff4SNick Piggin } 469ae361ff4SNick Piggin 470ae361ff4SNick Piggin int hostfs_write_end(struct file *file, struct address_space *mapping, 471ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied, 472ae361ff4SNick Piggin struct page *page, void *fsdata) 473ae361ff4SNick Piggin { 474ae361ff4SNick Piggin struct inode *inode = mapping->host; 475ae361ff4SNick Piggin void *buffer; 476ae361ff4SNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 4771da177e4SLinus Torvalds int err; 4781da177e4SLinus Torvalds 4791da177e4SLinus Torvalds buffer = kmap(page); 480ae361ff4SNick Piggin err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); 4811da177e4SLinus Torvalds kunmap(page); 4821da177e4SLinus Torvalds 483ae361ff4SNick Piggin if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) 484ae361ff4SNick Piggin SetPageUptodate(page); 4851da177e4SLinus Torvalds 48684b3db04SJeff Dike /* 48784b3db04SJeff Dike * If err > 0, write_file has added err to pos, so we are comparing 488ae361ff4SNick Piggin * i_size against the last byte written. 489ae361ff4SNick Piggin */ 490ae361ff4SNick Piggin if (err > 0 && (pos > inode->i_size)) 491ae361ff4SNick Piggin inode->i_size = pos; 492ae361ff4SNick Piggin unlock_page(page); 493ae361ff4SNick Piggin page_cache_release(page); 49430f04a4eSPaolo 'Blaisorblade' Giarrusso 495f1adc05eSJeff Dike return err; 4961da177e4SLinus Torvalds } 4971da177e4SLinus Torvalds 498f5e54d6eSChristoph Hellwig static const struct address_space_operations hostfs_aops = { 4991da177e4SLinus Torvalds .writepage = hostfs_writepage, 5001da177e4SLinus Torvalds .readpage = hostfs_readpage, 501ffa0aea6SPaolo 'Blaisorblade' Giarrusso .set_page_dirty = __set_page_dirty_nobuffers, 502ae361ff4SNick Piggin .write_begin = hostfs_write_begin, 503ae361ff4SNick Piggin .write_end = hostfs_write_end, 5041da177e4SLinus Torvalds }; 5051da177e4SLinus Torvalds 5064754b825SAl Viro static int read_name(struct inode *ino, char *name) 5071da177e4SLinus Torvalds { 5084754b825SAl Viro dev_t rdev; 5094754b825SAl Viro struct hostfs_stat st; 5104754b825SAl Viro int err = stat_file(name, &st, -1); 5114754b825SAl Viro if (err) 5124754b825SAl Viro return err; 5131da177e4SLinus Torvalds 5141da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/ 5154754b825SAl Viro rdev = MKDEV(st.maj, st.min); 5161da177e4SLinus Torvalds 5174754b825SAl Viro switch (st.mode & S_IFMT) { 5184754b825SAl Viro case S_IFLNK: 519d0352d3eSAl Viro ino->i_op = &hostfs_link_iops; 5204754b825SAl Viro break; 5214754b825SAl Viro case S_IFDIR: 5224754b825SAl Viro ino->i_op = &hostfs_dir_iops; 5234754b825SAl Viro ino->i_fop = &hostfs_dir_fops; 5244754b825SAl Viro break; 5254754b825SAl Viro case S_IFCHR: 5264754b825SAl Viro case S_IFBLK: 5274754b825SAl Viro case S_IFIFO: 5284754b825SAl Viro case S_IFSOCK: 5294754b825SAl Viro init_special_inode(ino, st.mode & S_IFMT, rdev); 5304754b825SAl Viro ino->i_op = &hostfs_iops; 5314754b825SAl Viro break; 5321da177e4SLinus Torvalds 5334754b825SAl Viro default: 5344754b825SAl Viro ino->i_op = &hostfs_iops; 5354754b825SAl Viro ino->i_fop = &hostfs_file_fops; 5364754b825SAl Viro ino->i_mapping->a_ops = &hostfs_aops; 5371da177e4SLinus Torvalds } 5384754b825SAl Viro 5394754b825SAl Viro ino->i_ino = st.ino; 5404754b825SAl Viro ino->i_mode = st.mode; 541bfe86848SMiklos Szeredi set_nlink(ino, st.nlink); 54229f82ae5SEric W. Biederman i_uid_write(ino, st.uid); 54329f82ae5SEric W. Biederman i_gid_write(ino, st.gid); 5444754b825SAl Viro ino->i_atime = st.atime; 5454754b825SAl Viro ino->i_mtime = st.mtime; 5464754b825SAl Viro ino->i_ctime = st.ctime; 5474754b825SAl Viro ino->i_size = st.size; 5484754b825SAl Viro ino->i_blocks = st.blocks; 5494754b825SAl Viro return 0; 5501da177e4SLinus Torvalds } 5511da177e4SLinus Torvalds 5524acdaf27SAl Viro int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, 553ebfc3b49SAl Viro bool excl) 5541da177e4SLinus Torvalds { 5551da177e4SLinus Torvalds struct inode *inode; 5561da177e4SLinus Torvalds char *name; 5571da177e4SLinus Torvalds int error, fd; 5581da177e4SLinus Torvalds 5590a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 5600a370e5dSDavid Howells if (IS_ERR(inode)) { 5610a370e5dSDavid Howells error = PTR_ERR(inode); 56284b3db04SJeff Dike goto out; 5630a370e5dSDavid Howells } 5641da177e4SLinus Torvalds 5651da177e4SLinus Torvalds error = -ENOMEM; 566c5322220SAl Viro name = dentry_name(dentry); 5671da177e4SLinus Torvalds if (name == NULL) 5681da177e4SLinus Torvalds goto out_put; 5691da177e4SLinus Torvalds 5701da177e4SLinus Torvalds fd = file_create(name, 5711da177e4SLinus Torvalds mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, 5721da177e4SLinus Torvalds mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, 5731da177e4SLinus Torvalds mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); 5744754b825SAl Viro if (fd < 0) 5751da177e4SLinus Torvalds error = fd; 5764754b825SAl Viro else 5775e2df28cSAl Viro error = read_name(inode, name); 5781da177e4SLinus Torvalds 579e9193059SAl Viro __putname(name); 5801da177e4SLinus Torvalds if (error) 5811da177e4SLinus Torvalds goto out_put; 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd; 5841da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; 5851da177e4SLinus Torvalds d_instantiate(dentry, inode); 586f1adc05eSJeff Dike return 0; 5871da177e4SLinus Torvalds 5881da177e4SLinus Torvalds out_put: 5891da177e4SLinus Torvalds iput(inode); 5901da177e4SLinus Torvalds out: 591f1adc05eSJeff Dike return error; 5921da177e4SLinus Torvalds } 5931da177e4SLinus Torvalds 5941da177e4SLinus Torvalds struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, 59500cd8dd3SAl Viro unsigned int flags) 5961da177e4SLinus Torvalds { 5971da177e4SLinus Torvalds struct inode *inode; 5981da177e4SLinus Torvalds char *name; 5991da177e4SLinus Torvalds int err; 6001da177e4SLinus Torvalds 6010a370e5dSDavid Howells inode = hostfs_iget(ino->i_sb); 6020a370e5dSDavid Howells if (IS_ERR(inode)) { 6030a370e5dSDavid Howells err = PTR_ERR(inode); 6041da177e4SLinus Torvalds goto out; 6050a370e5dSDavid Howells } 6061da177e4SLinus Torvalds 6071da177e4SLinus Torvalds err = -ENOMEM; 608c5322220SAl Viro name = dentry_name(dentry); 6091da177e4SLinus Torvalds if (name == NULL) 6101da177e4SLinus Torvalds goto out_put; 6111da177e4SLinus Torvalds 6121da177e4SLinus Torvalds err = read_name(inode, name); 6135e2df28cSAl Viro 614e9193059SAl Viro __putname(name); 6151da177e4SLinus Torvalds if (err == -ENOENT) { 6161da177e4SLinus Torvalds iput(inode); 6171da177e4SLinus Torvalds inode = NULL; 6181da177e4SLinus Torvalds } 6191da177e4SLinus Torvalds else if (err) 6201da177e4SLinus Torvalds goto out_put; 6211da177e4SLinus Torvalds 6221da177e4SLinus Torvalds d_add(dentry, inode); 623f1adc05eSJeff Dike return NULL; 6241da177e4SLinus Torvalds 6251da177e4SLinus Torvalds out_put: 6261da177e4SLinus Torvalds iput(inode); 6271da177e4SLinus Torvalds out: 628f1adc05eSJeff Dike return ERR_PTR(err); 6291da177e4SLinus Torvalds } 6301da177e4SLinus Torvalds 6311da177e4SLinus Torvalds int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) 6321da177e4SLinus Torvalds { 6331da177e4SLinus Torvalds char *from_name, *to_name; 6341da177e4SLinus Torvalds int err; 6351da177e4SLinus Torvalds 636c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 637f1adc05eSJeff Dike return -ENOMEM; 638c5322220SAl Viro to_name = dentry_name(to); 6391da177e4SLinus Torvalds if (to_name == NULL) { 640e9193059SAl Viro __putname(from_name); 641f1adc05eSJeff Dike return -ENOMEM; 6421da177e4SLinus Torvalds } 6431da177e4SLinus Torvalds err = link_file(to_name, from_name); 644e9193059SAl Viro __putname(from_name); 645e9193059SAl Viro __putname(to_name); 646f1adc05eSJeff Dike return err; 6471da177e4SLinus Torvalds } 6481da177e4SLinus Torvalds 6491da177e4SLinus Torvalds int hostfs_unlink(struct inode *ino, struct dentry *dentry) 6501da177e4SLinus Torvalds { 6511da177e4SLinus Torvalds char *file; 6521da177e4SLinus Torvalds int err; 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds if (append) 655f1adc05eSJeff Dike return -EPERM; 6561da177e4SLinus Torvalds 657f8d7e187SAl Viro if ((file = dentry_name(dentry)) == NULL) 658f8d7e187SAl Viro return -ENOMEM; 659f8d7e187SAl Viro 6601da177e4SLinus Torvalds err = unlink_file(file); 661e9193059SAl Viro __putname(file); 662f1adc05eSJeff Dike return err; 6631da177e4SLinus Torvalds } 6641da177e4SLinus Torvalds 6651da177e4SLinus Torvalds int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) 6661da177e4SLinus Torvalds { 6671da177e4SLinus Torvalds char *file; 6681da177e4SLinus Torvalds int err; 6691da177e4SLinus Torvalds 670c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 671f1adc05eSJeff Dike return -ENOMEM; 6721da177e4SLinus Torvalds err = make_symlink(file, to); 673e9193059SAl Viro __putname(file); 674f1adc05eSJeff Dike return err; 6751da177e4SLinus Torvalds } 6761da177e4SLinus Torvalds 67718bb1db3SAl Viro int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) 6781da177e4SLinus Torvalds { 6791da177e4SLinus Torvalds char *file; 6801da177e4SLinus Torvalds int err; 6811da177e4SLinus Torvalds 682c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 683f1adc05eSJeff Dike return -ENOMEM; 6841da177e4SLinus Torvalds err = do_mkdir(file, mode); 685e9193059SAl Viro __putname(file); 686f1adc05eSJeff Dike return err; 6871da177e4SLinus Torvalds } 6881da177e4SLinus Torvalds 6891da177e4SLinus Torvalds int hostfs_rmdir(struct inode *ino, struct dentry *dentry) 6901da177e4SLinus Torvalds { 6911da177e4SLinus Torvalds char *file; 6921da177e4SLinus Torvalds int err; 6931da177e4SLinus Torvalds 694c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL) 695f1adc05eSJeff Dike return -ENOMEM; 6961da177e4SLinus Torvalds err = do_rmdir(file); 697e9193059SAl Viro __putname(file); 698f1adc05eSJeff Dike return err; 6991da177e4SLinus Torvalds } 7001da177e4SLinus Torvalds 7011a67aafbSAl Viro static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) 7021da177e4SLinus Torvalds { 7031da177e4SLinus Torvalds struct inode *inode; 7041da177e4SLinus Torvalds char *name; 7050a370e5dSDavid Howells int err; 7061da177e4SLinus Torvalds 7070a370e5dSDavid Howells inode = hostfs_iget(dir->i_sb); 7080a370e5dSDavid Howells if (IS_ERR(inode)) { 7090a370e5dSDavid Howells err = PTR_ERR(inode); 7101da177e4SLinus Torvalds goto out; 7110a370e5dSDavid Howells } 7121da177e4SLinus Torvalds 7131da177e4SLinus Torvalds err = -ENOMEM; 714c5322220SAl Viro name = dentry_name(dentry); 7151da177e4SLinus Torvalds if (name == NULL) 7161da177e4SLinus Torvalds goto out_put; 7171da177e4SLinus Torvalds 7181da177e4SLinus Torvalds init_special_inode(inode, mode, dev); 71988f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); 720e9193059SAl Viro if (!err) 7211da177e4SLinus Torvalds goto out_free; 7221da177e4SLinus Torvalds 7231da177e4SLinus Torvalds err = read_name(inode, name); 724e9193059SAl Viro __putname(name); 7255e2df28cSAl Viro if (err) 7265e2df28cSAl Viro goto out_put; 7271da177e4SLinus Torvalds if (err) 7281da177e4SLinus Torvalds goto out_put; 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds d_instantiate(dentry, inode); 731f1adc05eSJeff Dike return 0; 7321da177e4SLinus Torvalds 7331da177e4SLinus Torvalds out_free: 734e9193059SAl Viro __putname(name); 7351da177e4SLinus Torvalds out_put: 7361da177e4SLinus Torvalds iput(inode); 7371da177e4SLinus Torvalds out: 738f1adc05eSJeff Dike return err; 7391da177e4SLinus Torvalds } 7401da177e4SLinus Torvalds 7411da177e4SLinus Torvalds int hostfs_rename(struct inode *from_ino, struct dentry *from, 7421da177e4SLinus Torvalds struct inode *to_ino, struct dentry *to) 7431da177e4SLinus Torvalds { 7441da177e4SLinus Torvalds char *from_name, *to_name; 7451da177e4SLinus Torvalds int err; 7461da177e4SLinus Torvalds 747c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL) 748f1adc05eSJeff Dike return -ENOMEM; 749c5322220SAl Viro if ((to_name = dentry_name(to)) == NULL) { 750e9193059SAl Viro __putname(from_name); 751f1adc05eSJeff Dike return -ENOMEM; 7521da177e4SLinus Torvalds } 7531da177e4SLinus Torvalds err = rename_file(from_name, to_name); 754e9193059SAl Viro __putname(from_name); 755e9193059SAl Viro __putname(to_name); 756f1adc05eSJeff Dike return err; 7571da177e4SLinus Torvalds } 7581da177e4SLinus Torvalds 75910556cb2SAl Viro int hostfs_permission(struct inode *ino, int desired) 7601da177e4SLinus Torvalds { 7611da177e4SLinus Torvalds char *name; 7621da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err; 7631da177e4SLinus Torvalds 76410556cb2SAl Viro if (desired & MAY_NOT_BLOCK) 765b74c79e9SNick Piggin return -ECHILD; 766b74c79e9SNick Piggin 7671da177e4SLinus Torvalds if (desired & MAY_READ) r = 1; 7681da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1; 7691da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1; 770c5322220SAl Viro name = inode_name(ino); 771f1adc05eSJeff Dike if (name == NULL) 772f1adc05eSJeff Dike return -ENOMEM; 7731da177e4SLinus Torvalds 7741da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || 7751da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) 7761da177e4SLinus Torvalds err = 0; 7771da177e4SLinus Torvalds else 7781da177e4SLinus Torvalds err = access_file(name, r, w, x); 779e9193059SAl Viro __putname(name); 7801da177e4SLinus Torvalds if (!err) 7812830ba7fSAl Viro err = generic_permission(ino, desired); 7821da177e4SLinus Torvalds return err; 7831da177e4SLinus Torvalds } 7841da177e4SLinus Torvalds 7851da177e4SLinus Torvalds int hostfs_setattr(struct dentry *dentry, struct iattr *attr) 7861da177e4SLinus Torvalds { 7871025774cSChristoph Hellwig struct inode *inode = dentry->d_inode; 7881da177e4SLinus Torvalds struct hostfs_iattr attrs; 7891da177e4SLinus Torvalds char *name; 7901da177e4SLinus Torvalds int err; 7911da177e4SLinus Torvalds 7921025774cSChristoph Hellwig int fd = HOSTFS_I(inode)->fd; 7935822b7faSAlberto Bertogli 7941025774cSChristoph Hellwig err = inode_change_ok(inode, attr); 7951da177e4SLinus Torvalds if (err) 7961da177e4SLinus Torvalds return err; 7971da177e4SLinus Torvalds 7981da177e4SLinus Torvalds if (append) 7991da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE; 8001da177e4SLinus Torvalds 8011da177e4SLinus Torvalds attrs.ia_valid = 0; 8021da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) { 8031da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE; 8041da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode; 8051da177e4SLinus Torvalds } 8061da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) { 8071da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID; 80829f82ae5SEric W. Biederman attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); 8091da177e4SLinus Torvalds } 8101da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) { 8111da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID; 81229f82ae5SEric W. Biederman attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); 8131da177e4SLinus Torvalds } 8141da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) { 8151da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE; 8161da177e4SLinus Torvalds attrs.ia_size = attr->ia_size; 8171da177e4SLinus Torvalds } 8181da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) { 8191da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME; 8201da177e4SLinus Torvalds attrs.ia_atime = attr->ia_atime; 8211da177e4SLinus Torvalds } 8221da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) { 8231da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME; 8241da177e4SLinus Torvalds attrs.ia_mtime = attr->ia_mtime; 8251da177e4SLinus Torvalds } 8261da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) { 8271da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME; 8281da177e4SLinus Torvalds attrs.ia_ctime = attr->ia_ctime; 8291da177e4SLinus Torvalds } 8301da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) { 8311da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; 8321da177e4SLinus Torvalds } 8331da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) { 8341da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; 8351da177e4SLinus Torvalds } 836c5322220SAl Viro name = dentry_name(dentry); 837f1adc05eSJeff Dike if (name == NULL) 838f1adc05eSJeff Dike return -ENOMEM; 8395822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd); 840e9193059SAl Viro __putname(name); 8411da177e4SLinus Torvalds if (err) 842f1adc05eSJeff Dike return err; 8431da177e4SLinus Torvalds 8441025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) && 845bc077320SMarco Stornelli attr->ia_size != i_size_read(inode)) 8463be2be0aSMarco Stornelli truncate_setsize(inode, attr->ia_size); 8471025774cSChristoph Hellwig 8481025774cSChristoph Hellwig setattr_copy(inode, attr); 8491025774cSChristoph Hellwig mark_inode_dirty(inode); 8501025774cSChristoph Hellwig return 0; 8511da177e4SLinus Torvalds } 8521da177e4SLinus Torvalds 85392e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = { 8541da177e4SLinus Torvalds .permission = hostfs_permission, 8551da177e4SLinus Torvalds .setattr = hostfs_setattr, 8561da177e4SLinus Torvalds }; 8571da177e4SLinus Torvalds 85892e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = { 8591da177e4SLinus Torvalds .create = hostfs_create, 8601da177e4SLinus Torvalds .lookup = hostfs_lookup, 8611da177e4SLinus Torvalds .link = hostfs_link, 8621da177e4SLinus Torvalds .unlink = hostfs_unlink, 8631da177e4SLinus Torvalds .symlink = hostfs_symlink, 8641da177e4SLinus Torvalds .mkdir = hostfs_mkdir, 8651da177e4SLinus Torvalds .rmdir = hostfs_rmdir, 8661da177e4SLinus Torvalds .mknod = hostfs_mknod, 8671da177e4SLinus Torvalds .rename = hostfs_rename, 8681da177e4SLinus Torvalds .permission = hostfs_permission, 8691da177e4SLinus Torvalds .setattr = hostfs_setattr, 8701da177e4SLinus Torvalds }; 8711da177e4SLinus Torvalds 872d0352d3eSAl Viro static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) 8731da177e4SLinus Torvalds { 874d0352d3eSAl Viro char *link = __getname(); 875d0352d3eSAl Viro if (link) { 876d0352d3eSAl Viro char *path = dentry_name(dentry); 877d0352d3eSAl Viro int err = -ENOMEM; 878d0352d3eSAl Viro if (path) { 8793b6036d1SAl Viro err = hostfs_do_readlink(path, link, PATH_MAX); 880d0352d3eSAl Viro if (err == PATH_MAX) 8811da177e4SLinus Torvalds err = -E2BIG; 882e9193059SAl Viro __putname(path); 8831da177e4SLinus Torvalds } 884d0352d3eSAl Viro if (err < 0) { 885d0352d3eSAl Viro __putname(link); 886d0352d3eSAl Viro link = ERR_PTR(err); 887d0352d3eSAl Viro } 888d0352d3eSAl Viro } else { 889d0352d3eSAl Viro link = ERR_PTR(-ENOMEM); 8901da177e4SLinus Torvalds } 8911da177e4SLinus Torvalds 892d0352d3eSAl Viro nd_set_link(nd, link); 893d0352d3eSAl Viro return NULL; 894d0352d3eSAl Viro } 895d0352d3eSAl Viro 896d0352d3eSAl Viro static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) 897d0352d3eSAl Viro { 898d0352d3eSAl Viro char *s = nd_get_link(nd); 899d0352d3eSAl Viro if (!IS_ERR(s)) 900d0352d3eSAl Viro __putname(s); 901d0352d3eSAl Viro } 902d0352d3eSAl Viro 903d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops = { 904d0352d3eSAl Viro .readlink = generic_readlink, 905d0352d3eSAl Viro .follow_link = hostfs_follow_link, 906d0352d3eSAl Viro .put_link = hostfs_put_link, 9071da177e4SLinus Torvalds }; 9081da177e4SLinus Torvalds 9091da177e4SLinus Torvalds static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) 9101da177e4SLinus Torvalds { 9111da177e4SLinus Torvalds struct inode *root_inode; 91275e8defbSPaolo 'Blaisorblade' Giarrusso char *host_root_path, *req_root = d; 9131da177e4SLinus Torvalds int err; 9141da177e4SLinus Torvalds 9151da177e4SLinus Torvalds sb->s_blocksize = 1024; 9161da177e4SLinus Torvalds sb->s_blocksize_bits = 10; 9171da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC; 9181da177e4SLinus Torvalds sb->s_op = &hostfs_sbops; 919b26d4cd3SAl Viro sb->s_d_op = &simple_dentry_operations; 920752fa51eSWolfgang Illmeyer sb->s_maxbytes = MAX_LFS_FILESIZE; 9211da177e4SLinus Torvalds 922a6eb0be6SPaolo 'Blaisorblade' Giarrusso /* NULL is printed as <NULL> by sprintf: avoid that. */ 92375e8defbSPaolo 'Blaisorblade' Giarrusso if (req_root == NULL) 92475e8defbSPaolo 'Blaisorblade' Giarrusso req_root = ""; 9251da177e4SLinus Torvalds 9261da177e4SLinus Torvalds err = -ENOMEM; 927601d2c38SAl Viro sb->s_fs_info = host_root_path = 928601d2c38SAl Viro kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); 92975e8defbSPaolo 'Blaisorblade' Giarrusso if (host_root_path == NULL) 9301da177e4SLinus Torvalds goto out; 9311da177e4SLinus Torvalds 93275e8defbSPaolo 'Blaisorblade' Giarrusso sprintf(host_root_path, "%s/%s", root_ino, req_root); 9331da177e4SLinus Torvalds 93452b209f7SAl Viro root_inode = new_inode(sb); 93552b209f7SAl Viro if (!root_inode) 936601d2c38SAl Viro goto out; 9371da177e4SLinus Torvalds 9384754b825SAl Viro err = read_name(root_inode, host_root_path); 9394754b825SAl Viro if (err) 9404754b825SAl Viro goto out_put; 94152b209f7SAl Viro 9424754b825SAl Viro if (S_ISLNK(root_inode->i_mode)) { 94352b209f7SAl Viro char *name = follow_link(host_root_path); 94452b209f7SAl Viro if (IS_ERR(name)) 94552b209f7SAl Viro err = PTR_ERR(name); 94652b209f7SAl Viro else 94752b209f7SAl Viro err = read_name(root_inode, name); 94852b209f7SAl Viro kfree(name); 9491da177e4SLinus Torvalds if (err) 9501da177e4SLinus Torvalds goto out_put; 9514754b825SAl Viro } 9521da177e4SLinus Torvalds 9531da177e4SLinus Torvalds err = -ENOMEM; 95448fde701SAl Viro sb->s_root = d_make_root(root_inode); 9551da177e4SLinus Torvalds if (sb->s_root == NULL) 95648fde701SAl Viro goto out; 9571da177e4SLinus Torvalds 958f1adc05eSJeff Dike return 0; 9591da177e4SLinus Torvalds 9601da177e4SLinus Torvalds out_put: 9611da177e4SLinus Torvalds iput(root_inode); 9621da177e4SLinus Torvalds out: 963f1adc05eSJeff Dike return err; 9641da177e4SLinus Torvalds } 9651da177e4SLinus Torvalds 9663c26ff6eSAl Viro static struct dentry *hostfs_read_sb(struct file_system_type *type, 9671da177e4SLinus Torvalds int flags, const char *dev_name, 9683c26ff6eSAl Viro void *data) 9691da177e4SLinus Torvalds { 9703c26ff6eSAl Viro return mount_nodev(type, flags, data, hostfs_fill_sb_common); 9711da177e4SLinus Torvalds } 9721da177e4SLinus Torvalds 973601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s) 974601d2c38SAl Viro { 975601d2c38SAl Viro kill_anon_super(s); 976601d2c38SAl Viro kfree(s->s_fs_info); 977601d2c38SAl Viro } 978601d2c38SAl Viro 9791da177e4SLinus Torvalds static struct file_system_type hostfs_type = { 9801da177e4SLinus Torvalds .owner = THIS_MODULE, 9811da177e4SLinus Torvalds .name = "hostfs", 9823c26ff6eSAl Viro .mount = hostfs_read_sb, 983601d2c38SAl Viro .kill_sb = hostfs_kill_sb, 9841da177e4SLinus Torvalds .fs_flags = 0, 9851da177e4SLinus Torvalds }; 9863e64fe5bSEric W. Biederman MODULE_ALIAS_FS("hostfs"); 9871da177e4SLinus Torvalds 9881da177e4SLinus Torvalds static int __init init_hostfs(void) 9891da177e4SLinus Torvalds { 990f1adc05eSJeff Dike return register_filesystem(&hostfs_type); 9911da177e4SLinus Torvalds } 9921da177e4SLinus Torvalds 9931da177e4SLinus Torvalds static void __exit exit_hostfs(void) 9941da177e4SLinus Torvalds { 9951da177e4SLinus Torvalds unregister_filesystem(&hostfs_type); 9961da177e4SLinus Torvalds } 9971da177e4SLinus Torvalds 9981da177e4SLinus Torvalds module_init(init_hostfs) 9991da177e4SLinus Torvalds module_exit(exit_hostfs) 10001da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1001