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>
17187c82cbSMatthew Wilcox (Oracle) #include <linux/writeback.h>
186966a977SJiri Kosina #include <linux/mount.h>
19cd140ce9SHongbo Li #include <linux/fs_context.h>
20ef9ca17cSHongbo Li #include <linux/fs_parser.h>
21d0352d3eSAl Viro #include <linux/namei.h>
221da177e4SLinus Torvalds #include "hostfs.h"
2337185b33SAl Viro #include <init.h>
2437185b33SAl Viro #include <kern.h>
251da177e4SLinus Torvalds
26cd140ce9SHongbo Li struct hostfs_fs_info {
27cd140ce9SHongbo Li char *host_root_path;
28cd140ce9SHongbo Li };
29cd140ce9SHongbo Li
301da177e4SLinus Torvalds struct hostfs_inode_info {
311da177e4SLinus Torvalds int fd;
32aeb5d727SAl Viro fmode_t mode;
331da177e4SLinus Torvalds struct inode vfs_inode;
3469886e67SRichard Weinberger struct mutex open_mutex;
3574ce793bSMickaël Salaün dev_t dev;
361da177e4SLinus Torvalds };
371da177e4SLinus Torvalds
HOSTFS_I(struct inode * inode)381da177e4SLinus Torvalds static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
391da177e4SLinus Torvalds {
40f1adc05eSJeff Dike return list_entry(inode, struct hostfs_inode_info, vfs_inode);
411da177e4SLinus Torvalds }
421da177e4SLinus Torvalds
43496ad9aaSAl Viro #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file))
441da177e4SLinus Torvalds
45a15f1e41SJohannes Berg static struct kmem_cache *hostfs_inode_cache;
46a15f1e41SJohannes Berg
471da177e4SLinus Torvalds /* Changed in hostfs_args before the kernel starts running */
48a6eb0be6SPaolo 'Blaisorblade' Giarrusso static char *root_ino = "";
491da177e4SLinus Torvalds static int append = 0;
501da177e4SLinus Torvalds
5192e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops;
5292e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops;
53d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops;
541da177e4SLinus Torvalds
551da177e4SLinus Torvalds #ifndef MODULE
hostfs_args(char * options,int * add)561da177e4SLinus Torvalds static int __init hostfs_args(char *options, int *add)
571da177e4SLinus Torvalds {
581da177e4SLinus Torvalds char *ptr;
591da177e4SLinus Torvalds
601da177e4SLinus Torvalds ptr = strchr(options, ',');
611da177e4SLinus Torvalds if (ptr != NULL)
621da177e4SLinus Torvalds *ptr++ = '\0';
631da177e4SLinus Torvalds if (*options != '\0')
641da177e4SLinus Torvalds root_ino = options;
651da177e4SLinus Torvalds
661da177e4SLinus Torvalds options = ptr;
671da177e4SLinus Torvalds while (options) {
681da177e4SLinus Torvalds ptr = strchr(options, ',');
691da177e4SLinus Torvalds if (ptr != NULL)
701da177e4SLinus Torvalds *ptr++ = '\0';
711da177e4SLinus Torvalds if (*options != '\0') {
721da177e4SLinus Torvalds if (!strcmp(options, "append"))
731da177e4SLinus Torvalds append = 1;
741da177e4SLinus Torvalds else printf("hostfs_args - unsupported option - %s\n",
751da177e4SLinus Torvalds options);
761da177e4SLinus Torvalds }
771da177e4SLinus Torvalds options = ptr;
781da177e4SLinus Torvalds }
79f1adc05eSJeff Dike return 0;
801da177e4SLinus Torvalds }
811da177e4SLinus Torvalds
821da177e4SLinus Torvalds __uml_setup("hostfs=", hostfs_args,
831da177e4SLinus Torvalds "hostfs=<root dir>,<flags>,...\n"
841da177e4SLinus Torvalds " This is used to set hostfs parameters. The root directory argument\n"
851da177e4SLinus Torvalds " is used to confine all hostfs mounts to within the specified directory\n"
861da177e4SLinus Torvalds " tree on the host. If this isn't specified, then a user inside UML can\n"
871da177e4SLinus Torvalds " mount anything on the host that's accessible to the user that's running\n"
881da177e4SLinus Torvalds " it.\n"
891da177e4SLinus Torvalds " The only flag currently supported is 'append', which specifies that all\n"
901da177e4SLinus Torvalds " files opened by hostfs will be opened in append mode.\n\n"
911da177e4SLinus Torvalds );
921da177e4SLinus Torvalds #endif
931da177e4SLinus Torvalds
__dentry_name(struct dentry * dentry,char * name)94e9193059SAl Viro static char *__dentry_name(struct dentry *dentry, char *name)
95e9193059SAl Viro {
96ec2447c2SNick Piggin char *p = dentry_path_raw(dentry, name, PATH_MAX);
97e9193059SAl Viro char *root;
98e9193059SAl Viro size_t len;
99cd140ce9SHongbo Li struct hostfs_fs_info *fsi;
100e9193059SAl Viro
101cd140ce9SHongbo Li fsi = dentry->d_sb->s_fs_info;
102cd140ce9SHongbo Li root = fsi->host_root_path;
103e9193059SAl Viro len = strlen(root);
104e9193059SAl Viro if (IS_ERR(p)) {
105e9193059SAl Viro __putname(name);
106e9193059SAl Viro return NULL;
107e9193059SAl Viro }
108aad50b1eSRichard Weinberger
109aad50b1eSRichard Weinberger /*
110aad50b1eSRichard Weinberger * This function relies on the fact that dentry_path_raw() will place
111aad50b1eSRichard Weinberger * the path name at the end of the provided buffer.
112aad50b1eSRichard Weinberger */
113aad50b1eSRichard Weinberger BUG_ON(p + strlen(p) + 1 != name + PATH_MAX);
114aad50b1eSRichard Weinberger
115b7f28a37SWolfram Sang strscpy(name, root, PATH_MAX);
116e9193059SAl Viro if (len > p - name) {
117e9193059SAl Viro __putname(name);
118e9193059SAl Viro return NULL;
119e9193059SAl Viro }
120c278e81bSRichard Weinberger
121c278e81bSRichard Weinberger if (p > name + len)
122c278e81bSRichard Weinberger strcpy(name + len, p);
123c278e81bSRichard Weinberger
124e9193059SAl Viro return name;
125e9193059SAl Viro }
126e9193059SAl Viro
dentry_name(struct dentry * dentry)127c5322220SAl Viro static char *dentry_name(struct dentry *dentry)
1281da177e4SLinus Torvalds {
129e9193059SAl Viro char *name = __getname();
130e9193059SAl Viro if (!name)
131f1adc05eSJeff Dike return NULL;
1321da177e4SLinus Torvalds
1339dcc5e8aSJames Hogan return __dentry_name(dentry, name);
1341da177e4SLinus Torvalds }
1351da177e4SLinus Torvalds
inode_name(struct inode * ino)136c5322220SAl Viro static char *inode_name(struct inode *ino)
1371da177e4SLinus Torvalds {
1381da177e4SLinus Torvalds struct dentry *dentry;
139ec2447c2SNick Piggin char *name;
140ec2447c2SNick Piggin
141ec2447c2SNick Piggin dentry = d_find_alias(ino);
142ec2447c2SNick Piggin if (!dentry)
143e9193059SAl Viro return NULL;
1441da177e4SLinus Torvalds
145ec2447c2SNick Piggin name = dentry_name(dentry);
146ec2447c2SNick Piggin
147ec2447c2SNick Piggin dput(dentry);
148ec2447c2SNick Piggin
149ec2447c2SNick Piggin return name;
1501da177e4SLinus Torvalds }
1511da177e4SLinus Torvalds
follow_link(char * link)1521da177e4SLinus Torvalds static char *follow_link(char *link)
1531da177e4SLinus Torvalds {
1541da177e4SLinus Torvalds char *name, *resolved, *end;
155b58c4e96SAndy Shevchenko int n;
1561da177e4SLinus Torvalds
1577f6c411cSAl Viro name = kmalloc(PATH_MAX, GFP_KERNEL);
1587c950992SRichard Weinberger if (!name) {
1591da177e4SLinus Torvalds n = -ENOMEM;
1607c950992SRichard Weinberger goto out_free;
1611da177e4SLinus Torvalds }
1627c950992SRichard Weinberger
1637c950992SRichard Weinberger n = hostfs_do_readlink(link, name, PATH_MAX);
1641da177e4SLinus Torvalds if (n < 0)
1651da177e4SLinus Torvalds goto out_free;
1667c950992SRichard Weinberger else if (n == PATH_MAX) {
1677c950992SRichard Weinberger n = -E2BIG;
1687c950992SRichard Weinberger goto out_free;
1697c950992SRichard Weinberger }
1701da177e4SLinus Torvalds
1711da177e4SLinus Torvalds if (*name == '/')
172f1adc05eSJeff Dike return name;
1731da177e4SLinus Torvalds
1741da177e4SLinus Torvalds end = strrchr(link, '/');
1751da177e4SLinus Torvalds if (end == NULL)
176f1adc05eSJeff Dike return name;
1771da177e4SLinus Torvalds
1781da177e4SLinus Torvalds *(end + 1) = '\0';
1791da177e4SLinus Torvalds
180b58c4e96SAndy Shevchenko resolved = kasprintf(GFP_KERNEL, "%s%s", link, name);
1811da177e4SLinus Torvalds if (resolved == NULL) {
1821da177e4SLinus Torvalds n = -ENOMEM;
1831da177e4SLinus Torvalds goto out_free;
1841da177e4SLinus Torvalds }
1851da177e4SLinus Torvalds
1867f6c411cSAl Viro kfree(name);
187f1adc05eSJeff Dike return resolved;
1881da177e4SLinus Torvalds
1891da177e4SLinus Torvalds out_free:
1907f6c411cSAl Viro kfree(name);
191f1adc05eSJeff Dike return ERR_PTR(n);
1921da177e4SLinus Torvalds }
1931da177e4SLinus Torvalds
hostfs_statfs(struct dentry * dentry,struct kstatfs * sf)1949e443bc3SJames Hogan static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
1951da177e4SLinus Torvalds {
19684b3db04SJeff Dike /*
19784b3db04SJeff Dike * do_statfs uses struct statfs64 internally, but the linux kernel
1981da177e4SLinus Torvalds * struct statfs still has 32-bit versions for most of these fields,
1991da177e4SLinus Torvalds * so we convert them here
2001da177e4SLinus Torvalds */
2011da177e4SLinus Torvalds int err;
2021da177e4SLinus Torvalds long long f_blocks;
2031da177e4SLinus Torvalds long long f_bfree;
2041da177e4SLinus Torvalds long long f_bavail;
2051da177e4SLinus Torvalds long long f_files;
2061da177e4SLinus Torvalds long long f_ffree;
207cd140ce9SHongbo Li struct hostfs_fs_info *fsi;
2081da177e4SLinus Torvalds
209cd140ce9SHongbo Li fsi = dentry->d_sb->s_fs_info;
210cd140ce9SHongbo Li err = do_statfs(fsi->host_root_path,
2111da177e4SLinus Torvalds &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
2121da177e4SLinus Torvalds &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
2131b627d57SRichard Weinberger &sf->f_namelen);
214f1adc05eSJeff Dike if (err)
215f1adc05eSJeff Dike return err;
2161da177e4SLinus Torvalds sf->f_blocks = f_blocks;
2171da177e4SLinus Torvalds sf->f_bfree = f_bfree;
2181da177e4SLinus Torvalds sf->f_bavail = f_bavail;
2191da177e4SLinus Torvalds sf->f_files = f_files;
2201da177e4SLinus Torvalds sf->f_ffree = f_ffree;
2211da177e4SLinus Torvalds sf->f_type = HOSTFS_SUPER_MAGIC;
222f1adc05eSJeff Dike return 0;
2231da177e4SLinus Torvalds }
2241da177e4SLinus Torvalds
hostfs_alloc_inode(struct super_block * sb)2251da177e4SLinus Torvalds static struct inode *hostfs_alloc_inode(struct super_block *sb)
2261da177e4SLinus Torvalds {
2271da177e4SLinus Torvalds struct hostfs_inode_info *hi;
2281da177e4SLinus Torvalds
229fd60b288SMuchun Song hi = alloc_inode_sb(sb, hostfs_inode_cache, GFP_KERNEL_ACCOUNT);
2301da177e4SLinus Torvalds if (hi == NULL)
231f1adc05eSJeff Dike return NULL;
232601d2c38SAl Viro hi->fd = -1;
233371fdab1SJames Hogan hi->mode = 0;
23474ce793bSMickaël Salaün hi->dev = 0;
2351da177e4SLinus Torvalds inode_init_once(&hi->vfs_inode);
23669886e67SRichard Weinberger mutex_init(&hi->open_mutex);
237f1adc05eSJeff Dike return &hi->vfs_inode;
2381da177e4SLinus Torvalds }
2391da177e4SLinus Torvalds
hostfs_evict_inode(struct inode * inode)240e971a6d7SAl Viro static void hostfs_evict_inode(struct inode *inode)
2411da177e4SLinus Torvalds {
24291b0abe3SJohannes Weiner truncate_inode_pages_final(&inode->i_data);
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;
24774ce793bSMickaël Salaün HOSTFS_I(inode)->dev = 0;
2481da177e4SLinus Torvalds }
2491da177e4SLinus Torvalds }
2501da177e4SLinus Torvalds
hostfs_free_inode(struct inode * inode)25108ccfc5cSAl Viro static void hostfs_free_inode(struct inode *inode)
252fa0d7e3dSNick Piggin {
253a15f1e41SJohannes Berg kmem_cache_free(hostfs_inode_cache, HOSTFS_I(inode));
254fa0d7e3dSNick Piggin }
255fa0d7e3dSNick Piggin
hostfs_show_options(struct seq_file * seq,struct dentry * root)25634c80b1dSAl Viro static int hostfs_show_options(struct seq_file *seq, struct dentry *root)
257dd2cc4dfSMiklos Szeredi {
258cd140ce9SHongbo Li struct hostfs_fs_info *fsi;
259cd140ce9SHongbo Li const char *root_path;
260cd140ce9SHongbo Li
261cd140ce9SHongbo Li fsi = root->d_sb->s_fs_info;
262cd140ce9SHongbo Li root_path = fsi->host_root_path;
263dd2cc4dfSMiklos Szeredi size_t offset = strlen(root_ino) + 1;
264dd2cc4dfSMiklos Szeredi
265dd2cc4dfSMiklos Szeredi if (strlen(root_path) > offset)
266a068acf2SKees Cook seq_show_option(seq, root_path + offset, NULL);
267dd2cc4dfSMiklos Szeredi
2687f74a668SRichard Weinberger if (append)
2697f74a668SRichard Weinberger seq_puts(seq, ",append");
2707f74a668SRichard Weinberger
271dd2cc4dfSMiklos Szeredi return 0;
272dd2cc4dfSMiklos Szeredi }
273dd2cc4dfSMiklos Szeredi
274ee9b6d61SJosef 'Jeff' Sipek static const struct super_operations hostfs_sbops = {
2751da177e4SLinus Torvalds .alloc_inode = hostfs_alloc_inode,
27608ccfc5cSAl Viro .free_inode = hostfs_free_inode,
27774ce793bSMickaël Salaün .drop_inode = generic_delete_inode,
278e971a6d7SAl Viro .evict_inode = hostfs_evict_inode,
2791da177e4SLinus Torvalds .statfs = hostfs_statfs,
280dd2cc4dfSMiklos Szeredi .show_options = hostfs_show_options,
2811da177e4SLinus Torvalds };
2821da177e4SLinus Torvalds
hostfs_readdir(struct file * file,struct dir_context * ctx)2839e443bc3SJames Hogan static int hostfs_readdir(struct file *file, struct dir_context *ctx)
2841da177e4SLinus Torvalds {
2851da177e4SLinus Torvalds void *dir;
2861da177e4SLinus Torvalds char *name;
2871da177e4SLinus Torvalds unsigned long long next, ino;
2881da177e4SLinus Torvalds int error, len;
2893ee6bd8eSGeert Uytterhoeven unsigned int type;
2901da177e4SLinus Torvalds
291c5322220SAl Viro name = dentry_name(file->f_path.dentry);
292f1adc05eSJeff Dike if (name == NULL)
293f1adc05eSJeff Dike return -ENOMEM;
2941da177e4SLinus Torvalds dir = open_dir(name, &error);
295e9193059SAl Viro __putname(name);
296f1adc05eSJeff Dike if (dir == NULL)
297f1adc05eSJeff Dike return -error;
2988e28bc7eSAl Viro next = ctx->pos;
2990c9bd636SRichard Weinberger seek_dir(dir, next);
3003ee6bd8eSGeert Uytterhoeven while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) {
3018e28bc7eSAl Viro if (!dir_emit(ctx, name, len, ino, type))
3028e28bc7eSAl Viro break;
3038e28bc7eSAl Viro ctx->pos = next;
3041da177e4SLinus Torvalds }
3051da177e4SLinus Torvalds close_dir(dir);
306f1adc05eSJeff Dike return 0;
3071da177e4SLinus Torvalds }
3081da177e4SLinus Torvalds
hostfs_open(struct inode * ino,struct file * file)3094c6dcafcSRichard Weinberger static int hostfs_open(struct inode *ino, struct file *file)
3101da177e4SLinus Torvalds {
3111da177e4SLinus Torvalds char *name;
312bd1052a2SRichard Weinberger fmode_t mode;
313f8ad850fSAl Viro int err;
314bd1052a2SRichard Weinberger int r, w, fd;
3151da177e4SLinus Torvalds
3161da177e4SLinus Torvalds mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
3171da177e4SLinus Torvalds if ((mode & HOSTFS_I(ino)->mode) == mode)
318f1adc05eSJeff Dike return 0;
3191da177e4SLinus Torvalds
320f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode;
3211da177e4SLinus Torvalds
322f8ad850fSAl Viro retry:
323a9d1958bSRichard Weinberger r = w = 0;
324a9d1958bSRichard Weinberger
325f8ad850fSAl Viro if (mode & FMODE_READ)
3261da177e4SLinus Torvalds r = 1;
327f8ad850fSAl Viro if (mode & FMODE_WRITE)
328112a5da7SRichard Weinberger r = w = 1;
3291da177e4SLinus Torvalds
330d692d397SAl Viro name = dentry_name(file_dentry(file));
3311da177e4SLinus Torvalds if (name == NULL)
332f1adc05eSJeff Dike return -ENOMEM;
3331da177e4SLinus Torvalds
3341da177e4SLinus Torvalds fd = open_file(name, r, w, append);
335e9193059SAl Viro __putname(name);
336f1adc05eSJeff Dike if (fd < 0)
337f1adc05eSJeff Dike return fd;
338f8ad850fSAl Viro
33969886e67SRichard Weinberger mutex_lock(&HOSTFS_I(ino)->open_mutex);
340f8ad850fSAl Viro /* somebody else had handled it first? */
341f8ad850fSAl Viro if ((mode & HOSTFS_I(ino)->mode) == mode) {
34269886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex);
343af955658SRichard Weinberger close_file(&fd);
344f8ad850fSAl Viro return 0;
345f8ad850fSAl Viro }
346f8ad850fSAl Viro if ((mode | HOSTFS_I(ino)->mode) != mode) {
347f8ad850fSAl Viro mode |= HOSTFS_I(ino)->mode;
34869886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex);
349f8ad850fSAl Viro close_file(&fd);
350f8ad850fSAl Viro goto retry;
351f8ad850fSAl Viro }
352f8ad850fSAl Viro if (HOSTFS_I(ino)->fd == -1) {
353f8ad850fSAl Viro HOSTFS_I(ino)->fd = fd;
354f8ad850fSAl Viro } else {
355f8ad850fSAl Viro err = replace_file(fd, HOSTFS_I(ino)->fd);
356f8ad850fSAl Viro close_file(&fd);
357f8ad850fSAl Viro if (err < 0) {
35869886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex);
359f8ad850fSAl Viro return err;
360f8ad850fSAl Viro }
361f8ad850fSAl Viro }
362f8ad850fSAl Viro HOSTFS_I(ino)->mode = mode;
36369886e67SRichard Weinberger mutex_unlock(&HOSTFS_I(ino)->open_mutex);
3641da177e4SLinus Torvalds
365f1adc05eSJeff Dike return 0;
3661da177e4SLinus Torvalds }
3671da177e4SLinus Torvalds
hostfs_file_release(struct inode * inode,struct file * file)36865984ff9SRichard Weinberger static int hostfs_file_release(struct inode *inode, struct file *file)
36965984ff9SRichard Weinberger {
37065984ff9SRichard Weinberger filemap_write_and_wait(inode->i_mapping);
37165984ff9SRichard Weinberger
37265984ff9SRichard Weinberger return 0;
37365984ff9SRichard Weinberger }
37465984ff9SRichard Weinberger
hostfs_fsync(struct file * file,loff_t start,loff_t end,int datasync)3759e443bc3SJames Hogan static int hostfs_fsync(struct file *file, loff_t start, loff_t end,
3769e443bc3SJames Hogan int datasync)
3771da177e4SLinus Torvalds {
37802c24a82SJosef Bacik struct inode *inode = file->f_mapping->host;
37902c24a82SJosef Bacik int ret;
38002c24a82SJosef Bacik
3813b49c9a1SJeff Layton ret = file_write_and_wait_range(file, start, end);
38202c24a82SJosef Bacik if (ret)
38302c24a82SJosef Bacik return ret;
38402c24a82SJosef Bacik
3855955102cSAl Viro inode_lock(inode);
38602c24a82SJosef Bacik ret = fsync_file(HOSTFS_I(inode)->fd, datasync);
3875955102cSAl Viro inode_unlock(inode);
38802c24a82SJosef Bacik
38902c24a82SJosef Bacik return ret;
3901da177e4SLinus Torvalds }
3911da177e4SLinus Torvalds
3924b6f5d20SArjan van de Ven static const struct file_operations hostfs_file_fops = {
3931da177e4SLinus Torvalds .llseek = generic_file_llseek,
3942cb1e089SDavid Howells .splice_read = filemap_splice_read,
3951568cb0eSJohannes Berg .splice_write = iter_file_splice_write,
396aad4f8bbSAl Viro .read_iter = generic_file_read_iter,
3978174202bSAl Viro .write_iter = generic_file_write_iter,
3981da177e4SLinus Torvalds .mmap = generic_file_mmap,
3994c6dcafcSRichard Weinberger .open = hostfs_open,
40065984ff9SRichard Weinberger .release = hostfs_file_release,
4011da177e4SLinus Torvalds .fsync = hostfs_fsync,
4021da177e4SLinus Torvalds };
4031da177e4SLinus Torvalds
4044b6f5d20SArjan van de Ven static const struct file_operations hostfs_dir_fops = {
4051da177e4SLinus Torvalds .llseek = generic_file_llseek,
406552a9d48SAl Viro .iterate_shared = hostfs_readdir,
4071da177e4SLinus Torvalds .read = generic_read_dir,
4084c6dcafcSRichard Weinberger .open = hostfs_open,
4094c6dcafcSRichard Weinberger .fsync = hostfs_fsync,
4101da177e4SLinus Torvalds };
4111da177e4SLinus Torvalds
hostfs_writepage(struct page * page,struct writeback_control * wbc)4129e443bc3SJames Hogan static int hostfs_writepage(struct page *page, struct writeback_control *wbc)
4131da177e4SLinus Torvalds {
4141da177e4SLinus Torvalds struct address_space *mapping = page->mapping;
4151da177e4SLinus Torvalds struct inode *inode = mapping->host;
4161da177e4SLinus Torvalds char *buffer;
417af6aa1b9SRichard Weinberger loff_t base = page_offset(page);
41809cbfeafSKirill A. Shutemov int count = PAGE_SIZE;
41909cbfeafSKirill A. Shutemov int end_index = inode->i_size >> PAGE_SHIFT;
4201da177e4SLinus Torvalds int err;
4211da177e4SLinus Torvalds
4221da177e4SLinus Torvalds if (page->index >= end_index)
42309cbfeafSKirill A. Shutemov count = inode->i_size & (PAGE_SIZE-1);
4241da177e4SLinus Torvalds
425e0820368SFabio M. De Francesco buffer = kmap_local_page(page);
4261da177e4SLinus Torvalds
4271da177e4SLinus Torvalds err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
4281da177e4SLinus Torvalds if (err != count) {
429e775dfb3SMatthew Wilcox (Oracle) if (err >= 0)
430e775dfb3SMatthew Wilcox (Oracle) err = -EIO;
431e775dfb3SMatthew Wilcox (Oracle) mapping_set_error(mapping, err);
4321da177e4SLinus Torvalds goto out;
4331da177e4SLinus Torvalds }
4341da177e4SLinus Torvalds
4351da177e4SLinus Torvalds if (base > inode->i_size)
4361da177e4SLinus Torvalds inode->i_size = base;
4371da177e4SLinus Torvalds
4381da177e4SLinus Torvalds err = 0;
4391da177e4SLinus Torvalds
4401da177e4SLinus Torvalds out:
441e0820368SFabio M. De Francesco kunmap_local(buffer);
4421da177e4SLinus Torvalds unlock_page(page);
443e0820368SFabio M. De Francesco
4441da177e4SLinus Torvalds return err;
4451da177e4SLinus Torvalds }
4461da177e4SLinus Torvalds
hostfs_read_folio(struct file * file,struct folio * folio)4478f4fe249SMatthew Wilcox (Oracle) static int hostfs_read_folio(struct file *file, struct folio *folio)
4481da177e4SLinus Torvalds {
4491da177e4SLinus Torvalds char *buffer;
450e3ec0fe9SMatthew Wilcox (Oracle) loff_t start = folio_pos(folio);
451b86b413aSRichard Weinberger int bytes_read, ret = 0;
4521da177e4SLinus Torvalds
453e3ec0fe9SMatthew Wilcox (Oracle) buffer = kmap_local_folio(folio, 0);
45441761ddfSRichard Weinberger bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
45509cbfeafSKirill A. Shutemov PAGE_SIZE);
456e3ec0fe9SMatthew Wilcox (Oracle) if (bytes_read < 0)
45741761ddfSRichard Weinberger ret = bytes_read;
458e3ec0fe9SMatthew Wilcox (Oracle) else
459e44be002SLinus Torvalds buffer = folio_zero_tail(folio, bytes_read, buffer + bytes_read);
460e0820368SFabio M. De Francesco kunmap_local(buffer);
461e0820368SFabio M. De Francesco
462e3ec0fe9SMatthew Wilcox (Oracle) folio_end_read(folio, ret == 0);
46341761ddfSRichard Weinberger return ret;
4641da177e4SLinus Torvalds }
4651da177e4SLinus Torvalds
hostfs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,struct folio ** foliop,void ** fsdata)4669e443bc3SJames Hogan static int hostfs_write_begin(struct file *file, struct address_space *mapping,
4679d6b0cd7SMatthew Wilcox (Oracle) loff_t pos, unsigned len,
468*1da86618SMatthew Wilcox (Oracle) struct folio **foliop, void **fsdata)
4691da177e4SLinus Torvalds {
47009cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT;
471ae361ff4SNick Piggin
472*1da86618SMatthew Wilcox (Oracle) *foliop = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
473*1da86618SMatthew Wilcox (Oracle) mapping_gfp_mask(mapping));
474*1da86618SMatthew Wilcox (Oracle) if (!*foliop)
475ae361ff4SNick Piggin return -ENOMEM;
476ae361ff4SNick Piggin return 0;
477ae361ff4SNick Piggin }
478ae361ff4SNick Piggin
hostfs_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct folio * folio,void * fsdata)4799e443bc3SJames Hogan static int hostfs_write_end(struct file *file, struct address_space *mapping,
480ae361ff4SNick Piggin loff_t pos, unsigned len, unsigned copied,
481a225800fSMatthew Wilcox (Oracle) struct folio *folio, void *fsdata)
482ae361ff4SNick Piggin {
483ae361ff4SNick Piggin struct inode *inode = mapping->host;
484ae361ff4SNick Piggin void *buffer;
48502d8a322SMatthew Wilcox (Oracle) size_t from = offset_in_folio(folio, pos);
4861da177e4SLinus Torvalds int err;
4871da177e4SLinus Torvalds
48802d8a322SMatthew Wilcox (Oracle) buffer = kmap_local_folio(folio, from);
48902d8a322SMatthew Wilcox (Oracle) err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer, copied);
490e0820368SFabio M. De Francesco kunmap_local(buffer);
4911da177e4SLinus Torvalds
49202d8a322SMatthew Wilcox (Oracle) if (!folio_test_uptodate(folio) && err == folio_size(folio))
49302d8a322SMatthew Wilcox (Oracle) folio_mark_uptodate(folio);
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;
50102d8a322SMatthew Wilcox (Oracle) folio_unlock(folio);
50202d8a322SMatthew Wilcox (Oracle) folio_put(folio);
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,
5098f4fe249SMatthew Wilcox (Oracle) .read_folio = hostfs_read_folio,
510187c82cbSMatthew Wilcox (Oracle) .dirty_folio = filemap_dirty_folio,
511ae361ff4SNick Piggin .write_begin = hostfs_write_begin,
512ae361ff4SNick Piggin .write_end = hostfs_write_end,
5131da177e4SLinus Torvalds };
5141da177e4SLinus Torvalds
hostfs_inode_update(struct inode * ino,const struct hostfs_stat * st)51574ce793bSMickaël Salaün static int hostfs_inode_update(struct inode *ino, const struct hostfs_stat *st)
5161da177e4SLinus Torvalds {
51774ce793bSMickaël Salaün set_nlink(ino, st->nlink);
51874ce793bSMickaël Salaün i_uid_write(ino, st->uid);
51974ce793bSMickaël Salaün i_gid_write(ino, st->gid);
520c461ba5dSJeff Layton inode_set_atime_to_ts(ino, (struct timespec64){
521c461ba5dSJeff Layton st->atime.tv_sec,
522c461ba5dSJeff Layton st->atime.tv_nsec,
523c461ba5dSJeff Layton });
524c461ba5dSJeff Layton inode_set_mtime_to_ts(ino, (struct timespec64){
525c461ba5dSJeff Layton st->mtime.tv_sec,
526c461ba5dSJeff Layton st->mtime.tv_nsec,
527c461ba5dSJeff Layton });
52866e79d89SJeff Layton inode_set_ctime(ino, st->ctime.tv_sec, st->ctime.tv_nsec);
52974ce793bSMickaël Salaün ino->i_size = st->size;
53074ce793bSMickaël Salaün ino->i_blocks = st->blocks;
53174ce793bSMickaël Salaün return 0;
53274ce793bSMickaël Salaün }
53374ce793bSMickaël Salaün
hostfs_inode_set(struct inode * ino,void * data)53474ce793bSMickaël Salaün static int hostfs_inode_set(struct inode *ino, void *data)
53574ce793bSMickaël Salaün {
53674ce793bSMickaël Salaün struct hostfs_stat *st = data;
537267ed02cSJohannes Berg dev_t dev, rdev;
5381da177e4SLinus Torvalds
5391da177e4SLinus Torvalds /* Reencode maj and min with the kernel encoding.*/
540267ed02cSJohannes Berg rdev = MKDEV(st->rdev.maj, st->rdev.min);
541267ed02cSJohannes Berg dev = MKDEV(st->dev.maj, st->dev.min);
5421da177e4SLinus Torvalds
54374ce793bSMickaël Salaün switch (st->mode & S_IFMT) {
5444754b825SAl Viro case S_IFLNK:
545d0352d3eSAl Viro ino->i_op = &hostfs_link_iops;
5464754b825SAl Viro break;
5474754b825SAl Viro case S_IFDIR:
5484754b825SAl Viro ino->i_op = &hostfs_dir_iops;
5494754b825SAl Viro ino->i_fop = &hostfs_dir_fops;
5504754b825SAl Viro break;
5514754b825SAl Viro case S_IFCHR:
5524754b825SAl Viro case S_IFBLK:
5534754b825SAl Viro case S_IFIFO:
5544754b825SAl Viro case S_IFSOCK:
55574ce793bSMickaël Salaün init_special_inode(ino, st->mode & S_IFMT, rdev);
5564754b825SAl Viro ino->i_op = &hostfs_iops;
5574754b825SAl Viro break;
5582ad2dca6SRichard Weinberger case S_IFREG:
5594754b825SAl Viro ino->i_op = &hostfs_iops;
5604754b825SAl Viro ino->i_fop = &hostfs_file_fops;
5614754b825SAl Viro ino->i_mapping->a_ops = &hostfs_aops;
5622ad2dca6SRichard Weinberger break;
5632ad2dca6SRichard Weinberger default:
5642ad2dca6SRichard Weinberger return -EIO;
5651da177e4SLinus Torvalds }
5664754b825SAl Viro
567267ed02cSJohannes Berg HOSTFS_I(ino)->dev = dev;
56874ce793bSMickaël Salaün ino->i_ino = st->ino;
56974ce793bSMickaël Salaün ino->i_mode = st->mode;
57074ce793bSMickaël Salaün return hostfs_inode_update(ino, st);
57174ce793bSMickaël Salaün }
57274ce793bSMickaël Salaün
hostfs_inode_test(struct inode * inode,void * data)57374ce793bSMickaël Salaün static int hostfs_inode_test(struct inode *inode, void *data)
57474ce793bSMickaël Salaün {
57574ce793bSMickaël Salaün const struct hostfs_stat *st = data;
576267ed02cSJohannes Berg dev_t dev = MKDEV(st->dev.maj, st->dev.min);
57774ce793bSMickaël Salaün
578267ed02cSJohannes Berg return inode->i_ino == st->ino && HOSTFS_I(inode)->dev == dev;
57974ce793bSMickaël Salaün }
58074ce793bSMickaël Salaün
hostfs_iget(struct super_block * sb,char * name)58174ce793bSMickaël Salaün static struct inode *hostfs_iget(struct super_block *sb, char *name)
58274ce793bSMickaël Salaün {
58374ce793bSMickaël Salaün struct inode *inode;
58474ce793bSMickaël Salaün struct hostfs_stat st;
58574ce793bSMickaël Salaün int err = stat_file(name, &st, -1);
58674ce793bSMickaël Salaün
58774ce793bSMickaël Salaün if (err)
58874ce793bSMickaël Salaün return ERR_PTR(err);
58974ce793bSMickaël Salaün
59074ce793bSMickaël Salaün inode = iget5_locked(sb, st.ino, hostfs_inode_test, hostfs_inode_set,
59174ce793bSMickaël Salaün &st);
59274ce793bSMickaël Salaün if (!inode)
59374ce793bSMickaël Salaün return ERR_PTR(-ENOMEM);
59474ce793bSMickaël Salaün
59574ce793bSMickaël Salaün if (inode->i_state & I_NEW) {
59674ce793bSMickaël Salaün unlock_new_inode(inode);
59774ce793bSMickaël Salaün } else {
59874ce793bSMickaël Salaün spin_lock(&inode->i_lock);
59974ce793bSMickaël Salaün hostfs_inode_update(inode, &st);
60074ce793bSMickaël Salaün spin_unlock(&inode->i_lock);
60174ce793bSMickaël Salaün }
60274ce793bSMickaël Salaün
60374ce793bSMickaël Salaün return inode;
6041da177e4SLinus Torvalds }
6051da177e4SLinus Torvalds
hostfs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)6066c960e68SChristian Brauner static int hostfs_create(struct mnt_idmap *idmap, struct inode *dir,
607549c7297SChristian Brauner struct dentry *dentry, umode_t mode, bool excl)
6081da177e4SLinus Torvalds {
6091da177e4SLinus Torvalds struct inode *inode;
6101da177e4SLinus Torvalds char *name;
61174ce793bSMickaël Salaün int fd;
6121da177e4SLinus Torvalds
613c5322220SAl Viro name = dentry_name(dentry);
6141da177e4SLinus Torvalds if (name == NULL)
61574ce793bSMickaël Salaün return -ENOMEM;
6161da177e4SLinus Torvalds
617a718c922SRichard Weinberger fd = file_create(name, mode & 0777);
61874ce793bSMickaël Salaün if (fd < 0) {
619e9193059SAl Viro __putname(name);
62074ce793bSMickaël Salaün return fd;
62174ce793bSMickaël Salaün }
62274ce793bSMickaël Salaün
62374ce793bSMickaël Salaün inode = hostfs_iget(dir->i_sb, name);
62474ce793bSMickaël Salaün __putname(name);
62574ce793bSMickaël Salaün if (IS_ERR(inode))
62674ce793bSMickaël Salaün return PTR_ERR(inode);
6271da177e4SLinus Torvalds
6281da177e4SLinus Torvalds HOSTFS_I(inode)->fd = fd;
6291da177e4SLinus Torvalds HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
6301da177e4SLinus Torvalds d_instantiate(dentry, inode);
631f1adc05eSJeff Dike return 0;
6321da177e4SLinus Torvalds }
6331da177e4SLinus Torvalds
hostfs_lookup(struct inode * ino,struct dentry * dentry,unsigned int flags)6349e443bc3SJames Hogan static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
63500cd8dd3SAl Viro unsigned int flags)
6361da177e4SLinus Torvalds {
63774ce793bSMickaël Salaün struct inode *inode = NULL;
6381da177e4SLinus Torvalds char *name;
6391da177e4SLinus Torvalds
640c5322220SAl Viro name = dentry_name(dentry);
64174ce793bSMickaël Salaün if (name == NULL)
64274ce793bSMickaël Salaün return ERR_PTR(-ENOMEM);
64374ce793bSMickaël Salaün
64474ce793bSMickaël Salaün inode = hostfs_iget(ino->i_sb, name);
645e9193059SAl Viro __putname(name);
6466f36230eSAl Viro if (inode == ERR_PTR(-ENOENT))
64774ce793bSMickaël Salaün inode = NULL;
64874ce793bSMickaël Salaün
64950f30740SAl Viro return d_splice_alias(inode, dentry);
6501da177e4SLinus Torvalds }
6511da177e4SLinus Torvalds
hostfs_link(struct dentry * to,struct inode * ino,struct dentry * from)6529e443bc3SJames Hogan static int hostfs_link(struct dentry *to, struct inode *ino,
6539e443bc3SJames Hogan struct dentry *from)
6541da177e4SLinus Torvalds {
6551da177e4SLinus Torvalds char *from_name, *to_name;
6561da177e4SLinus Torvalds int err;
6571da177e4SLinus Torvalds
658c5322220SAl Viro if ((from_name = dentry_name(from)) == NULL)
659f1adc05eSJeff Dike return -ENOMEM;
660c5322220SAl Viro to_name = dentry_name(to);
6611da177e4SLinus Torvalds if (to_name == NULL) {
662e9193059SAl Viro __putname(from_name);
663f1adc05eSJeff Dike return -ENOMEM;
6641da177e4SLinus Torvalds }
6651da177e4SLinus Torvalds err = link_file(to_name, from_name);
666e9193059SAl Viro __putname(from_name);
667e9193059SAl Viro __putname(to_name);
668f1adc05eSJeff Dike return err;
6691da177e4SLinus Torvalds }
6701da177e4SLinus Torvalds
hostfs_unlink(struct inode * ino,struct dentry * dentry)6719e443bc3SJames Hogan static int hostfs_unlink(struct inode *ino, struct dentry *dentry)
6721da177e4SLinus Torvalds {
6731da177e4SLinus Torvalds char *file;
6741da177e4SLinus Torvalds int err;
6751da177e4SLinus Torvalds
6761da177e4SLinus Torvalds if (append)
677f1adc05eSJeff Dike return -EPERM;
6781da177e4SLinus Torvalds
679f8d7e187SAl Viro if ((file = dentry_name(dentry)) == NULL)
680f8d7e187SAl Viro return -ENOMEM;
681f8d7e187SAl Viro
6821da177e4SLinus Torvalds err = unlink_file(file);
683e9193059SAl Viro __putname(file);
684f1adc05eSJeff Dike return err;
6851da177e4SLinus Torvalds }
6861da177e4SLinus Torvalds
hostfs_symlink(struct mnt_idmap * idmap,struct inode * ino,struct dentry * dentry,const char * to)6877a77db95SChristian Brauner static int hostfs_symlink(struct mnt_idmap *idmap, struct inode *ino,
688549c7297SChristian Brauner struct dentry *dentry, const char *to)
6891da177e4SLinus Torvalds {
6901da177e4SLinus Torvalds char *file;
6911da177e4SLinus Torvalds int err;
6921da177e4SLinus Torvalds
693c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL)
694f1adc05eSJeff Dike return -ENOMEM;
6951da177e4SLinus Torvalds err = make_symlink(file, to);
696e9193059SAl Viro __putname(file);
697f1adc05eSJeff Dike return err;
6981da177e4SLinus Torvalds }
6991da177e4SLinus Torvalds
hostfs_mkdir(struct mnt_idmap * idmap,struct inode * ino,struct dentry * dentry,umode_t mode)700c54bd91eSChristian Brauner static int hostfs_mkdir(struct mnt_idmap *idmap, struct inode *ino,
701549c7297SChristian Brauner struct dentry *dentry, umode_t mode)
7021da177e4SLinus Torvalds {
7031da177e4SLinus Torvalds char *file;
7041da177e4SLinus Torvalds int err;
7051da177e4SLinus Torvalds
706c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL)
707f1adc05eSJeff Dike return -ENOMEM;
7081da177e4SLinus Torvalds err = do_mkdir(file, mode);
709e9193059SAl Viro __putname(file);
710f1adc05eSJeff Dike return err;
7111da177e4SLinus Torvalds }
7121da177e4SLinus Torvalds
hostfs_rmdir(struct inode * ino,struct dentry * dentry)7139e443bc3SJames Hogan static int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
7141da177e4SLinus Torvalds {
7151da177e4SLinus Torvalds char *file;
7161da177e4SLinus Torvalds int err;
7171da177e4SLinus Torvalds
718c5322220SAl Viro if ((file = dentry_name(dentry)) == NULL)
719f1adc05eSJeff Dike return -ENOMEM;
7206380161cSDominik Brodowski err = hostfs_do_rmdir(file);
721e9193059SAl Viro __putname(file);
722f1adc05eSJeff Dike return err;
7231da177e4SLinus Torvalds }
7241da177e4SLinus Torvalds
hostfs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)7255ebb29beSChristian Brauner static int hostfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
726549c7297SChristian Brauner struct dentry *dentry, umode_t mode, dev_t dev)
7271da177e4SLinus Torvalds {
7281da177e4SLinus Torvalds struct inode *inode;
7291da177e4SLinus Torvalds char *name;
7300a370e5dSDavid Howells int err;
7311da177e4SLinus Torvalds
732c5322220SAl Viro name = dentry_name(dentry);
7331da177e4SLinus Torvalds if (name == NULL)
73474ce793bSMickaël Salaün return -ENOMEM;
7351da177e4SLinus Torvalds
73688f6cd0cSJohannes Stezenbach err = do_mknod(name, mode, MAJOR(dev), MINOR(dev));
73774ce793bSMickaël Salaün if (err) {
738e9193059SAl Viro __putname(name);
73974ce793bSMickaël Salaün return err;
74074ce793bSMickaël Salaün }
74174ce793bSMickaël Salaün
74274ce793bSMickaël Salaün inode = hostfs_iget(dir->i_sb, name);
74374ce793bSMickaël Salaün __putname(name);
74474ce793bSMickaël Salaün if (IS_ERR(inode))
74574ce793bSMickaël Salaün return PTR_ERR(inode);
7461da177e4SLinus Torvalds
7471da177e4SLinus Torvalds d_instantiate(dentry, inode);
748f1adc05eSJeff Dike return 0;
7491da177e4SLinus Torvalds }
7501da177e4SLinus Torvalds
hostfs_rename2(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)751e18275aeSChristian Brauner static int hostfs_rename2(struct mnt_idmap *idmap,
752549c7297SChristian Brauner struct inode *old_dir, struct dentry *old_dentry,
7539a423bb6SMiklos Szeredi struct inode *new_dir, struct dentry *new_dentry,
7549a423bb6SMiklos Szeredi unsigned int flags)
7551da177e4SLinus Torvalds {
7569a423bb6SMiklos Szeredi char *old_name, *new_name;
7571da177e4SLinus Torvalds int err;
7581da177e4SLinus Torvalds
7599a423bb6SMiklos Szeredi if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
7609a423bb6SMiklos Szeredi return -EINVAL;
7619a423bb6SMiklos Szeredi
7629a423bb6SMiklos Szeredi old_name = dentry_name(old_dentry);
7639a423bb6SMiklos Szeredi if (old_name == NULL)
764f1adc05eSJeff Dike return -ENOMEM;
7659a423bb6SMiklos Szeredi new_name = dentry_name(new_dentry);
7669a423bb6SMiklos Szeredi if (new_name == NULL) {
7679a423bb6SMiklos Szeredi __putname(old_name);
768f1adc05eSJeff Dike return -ENOMEM;
7691da177e4SLinus Torvalds }
7709a423bb6SMiklos Szeredi if (!flags)
7719a423bb6SMiklos Szeredi err = rename_file(old_name, new_name);
7729a423bb6SMiklos Szeredi else
7739a423bb6SMiklos Szeredi err = rename2_file(old_name, new_name, flags);
7749a423bb6SMiklos Szeredi
7759a423bb6SMiklos Szeredi __putname(old_name);
7769a423bb6SMiklos Szeredi __putname(new_name);
777f1adc05eSJeff Dike return err;
7781da177e4SLinus Torvalds }
7791da177e4SLinus Torvalds
hostfs_permission(struct mnt_idmap * idmap,struct inode * ino,int desired)7804609e1f1SChristian Brauner static int hostfs_permission(struct mnt_idmap *idmap,
781549c7297SChristian Brauner struct inode *ino, int desired)
7821da177e4SLinus Torvalds {
7831da177e4SLinus Torvalds char *name;
7841da177e4SLinus Torvalds int r = 0, w = 0, x = 0, err;
7851da177e4SLinus Torvalds
78610556cb2SAl Viro if (desired & MAY_NOT_BLOCK)
787b74c79e9SNick Piggin return -ECHILD;
788b74c79e9SNick Piggin
7891da177e4SLinus Torvalds if (desired & MAY_READ) r = 1;
7901da177e4SLinus Torvalds if (desired & MAY_WRITE) w = 1;
7911da177e4SLinus Torvalds if (desired & MAY_EXEC) x = 1;
792c5322220SAl Viro name = inode_name(ino);
793f1adc05eSJeff Dike if (name == NULL)
794f1adc05eSJeff Dike return -ENOMEM;
7951da177e4SLinus Torvalds
7961da177e4SLinus Torvalds if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) ||
7971da177e4SLinus Torvalds S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode))
7981da177e4SLinus Torvalds err = 0;
7991da177e4SLinus Torvalds else
8001da177e4SLinus Torvalds err = access_file(name, r, w, x);
801e9193059SAl Viro __putname(name);
8021da177e4SLinus Torvalds if (!err)
8034609e1f1SChristian Brauner err = generic_permission(&nop_mnt_idmap, ino, desired);
8041da177e4SLinus Torvalds return err;
8051da177e4SLinus Torvalds }
8061da177e4SLinus Torvalds
hostfs_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)807c1632a0fSChristian Brauner static int hostfs_setattr(struct mnt_idmap *idmap,
808549c7297SChristian Brauner struct dentry *dentry, struct iattr *attr)
8091da177e4SLinus Torvalds {
8102b0143b5SDavid Howells struct inode *inode = d_inode(dentry);
8111da177e4SLinus Torvalds struct hostfs_iattr attrs;
8121da177e4SLinus Torvalds char *name;
8131da177e4SLinus Torvalds int err;
8141da177e4SLinus Torvalds
8151025774cSChristoph Hellwig int fd = HOSTFS_I(inode)->fd;
8165822b7faSAlberto Bertogli
817c1632a0fSChristian Brauner err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
8181da177e4SLinus Torvalds if (err)
8191da177e4SLinus Torvalds return err;
8201da177e4SLinus Torvalds
8211da177e4SLinus Torvalds if (append)
8221da177e4SLinus Torvalds attr->ia_valid &= ~ATTR_SIZE;
8231da177e4SLinus Torvalds
8241da177e4SLinus Torvalds attrs.ia_valid = 0;
8251da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MODE) {
8261da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MODE;
8271da177e4SLinus Torvalds attrs.ia_mode = attr->ia_mode;
8281da177e4SLinus Torvalds }
8291da177e4SLinus Torvalds if (attr->ia_valid & ATTR_UID) {
8301da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_UID;
83129f82ae5SEric W. Biederman attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid);
8321da177e4SLinus Torvalds }
8331da177e4SLinus Torvalds if (attr->ia_valid & ATTR_GID) {
8341da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_GID;
83529f82ae5SEric W. Biederman attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid);
8361da177e4SLinus Torvalds }
8371da177e4SLinus Torvalds if (attr->ia_valid & ATTR_SIZE) {
8381da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_SIZE;
8391da177e4SLinus Torvalds attrs.ia_size = attr->ia_size;
8401da177e4SLinus Torvalds }
8411da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME) {
8421da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME;
843bca30265SArnd Bergmann attrs.ia_atime = (struct hostfs_timespec)
844bca30265SArnd Bergmann { attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec };
8451da177e4SLinus Torvalds }
8461da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME) {
8471da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME;
848bca30265SArnd Bergmann attrs.ia_mtime = (struct hostfs_timespec)
849bca30265SArnd Bergmann { attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec };
8501da177e4SLinus Torvalds }
8511da177e4SLinus Torvalds if (attr->ia_valid & ATTR_CTIME) {
8521da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_CTIME;
853bca30265SArnd Bergmann attrs.ia_ctime = (struct hostfs_timespec)
854bca30265SArnd Bergmann { attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec };
8551da177e4SLinus Torvalds }
8561da177e4SLinus Torvalds if (attr->ia_valid & ATTR_ATIME_SET) {
8571da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET;
8581da177e4SLinus Torvalds }
8591da177e4SLinus Torvalds if (attr->ia_valid & ATTR_MTIME_SET) {
8601da177e4SLinus Torvalds attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET;
8611da177e4SLinus Torvalds }
862c5322220SAl Viro name = dentry_name(dentry);
863f1adc05eSJeff Dike if (name == NULL)
864f1adc05eSJeff Dike return -ENOMEM;
8655822b7faSAlberto Bertogli err = set_attr(name, &attrs, fd);
866e9193059SAl Viro __putname(name);
8671da177e4SLinus Torvalds if (err)
868f1adc05eSJeff Dike return err;
8691da177e4SLinus Torvalds
8701025774cSChristoph Hellwig if ((attr->ia_valid & ATTR_SIZE) &&
871bc077320SMarco Stornelli attr->ia_size != i_size_read(inode))
8723be2be0aSMarco Stornelli truncate_setsize(inode, attr->ia_size);
8731025774cSChristoph Hellwig
874c1632a0fSChristian Brauner setattr_copy(&nop_mnt_idmap, inode, attr);
8751025774cSChristoph Hellwig mark_inode_dirty(inode);
8761025774cSChristoph Hellwig return 0;
8771da177e4SLinus Torvalds }
8781da177e4SLinus Torvalds
87992e1d5beSArjan van de Ven static const struct inode_operations hostfs_iops = {
8801da177e4SLinus Torvalds .permission = hostfs_permission,
8811da177e4SLinus Torvalds .setattr = hostfs_setattr,
8821da177e4SLinus Torvalds };
8831da177e4SLinus Torvalds
88492e1d5beSArjan van de Ven static const struct inode_operations hostfs_dir_iops = {
8851da177e4SLinus Torvalds .create = hostfs_create,
8861da177e4SLinus Torvalds .lookup = hostfs_lookup,
8871da177e4SLinus Torvalds .link = hostfs_link,
8881da177e4SLinus Torvalds .unlink = hostfs_unlink,
8891da177e4SLinus Torvalds .symlink = hostfs_symlink,
8901da177e4SLinus Torvalds .mkdir = hostfs_mkdir,
8911da177e4SLinus Torvalds .rmdir = hostfs_rmdir,
8921da177e4SLinus Torvalds .mknod = hostfs_mknod,
8932773bf00SMiklos Szeredi .rename = hostfs_rename2,
8941da177e4SLinus Torvalds .permission = hostfs_permission,
8951da177e4SLinus Torvalds .setattr = hostfs_setattr,
8961da177e4SLinus Torvalds };
8971da177e4SLinus Torvalds
hostfs_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)8986b255391SAl Viro static const char *hostfs_get_link(struct dentry *dentry,
899fceef393SAl Viro struct inode *inode,
900fceef393SAl Viro struct delayed_call *done)
9011da177e4SLinus Torvalds {
9026b255391SAl Viro char *link;
9036b255391SAl Viro if (!dentry)
9046b255391SAl Viro return ERR_PTR(-ECHILD);
905fceef393SAl Viro link = kmalloc(PATH_MAX, GFP_KERNEL);
906d0352d3eSAl Viro if (link) {
907d0352d3eSAl Viro char *path = dentry_name(dentry);
908d0352d3eSAl Viro int err = -ENOMEM;
909d0352d3eSAl Viro if (path) {
9103b6036d1SAl Viro err = hostfs_do_readlink(path, link, PATH_MAX);
911d0352d3eSAl Viro if (err == PATH_MAX)
9121da177e4SLinus Torvalds err = -E2BIG;
913e9193059SAl Viro __putname(path);
9141da177e4SLinus Torvalds }
915d0352d3eSAl Viro if (err < 0) {
916fceef393SAl Viro kfree(link);
917680baacbSAl Viro return ERR_PTR(err);
918d0352d3eSAl Viro }
919d0352d3eSAl Viro } else {
920680baacbSAl Viro return ERR_PTR(-ENOMEM);
9211da177e4SLinus Torvalds }
9221da177e4SLinus Torvalds
923fceef393SAl Viro set_delayed_call(done, kfree_link, link);
924fceef393SAl Viro return link;
925d0352d3eSAl Viro }
926d0352d3eSAl Viro
927d0352d3eSAl Viro static const struct inode_operations hostfs_link_iops = {
9286b255391SAl Viro .get_link = hostfs_get_link,
9291da177e4SLinus Torvalds };
9301da177e4SLinus Torvalds
hostfs_fill_super(struct super_block * sb,struct fs_context * fc)931cd140ce9SHongbo Li static int hostfs_fill_super(struct super_block *sb, struct fs_context *fc)
9321da177e4SLinus Torvalds {
933cd140ce9SHongbo Li struct hostfs_fs_info *fsi = sb->s_fs_info;
9341da177e4SLinus Torvalds struct inode *root_inode;
9351da177e4SLinus Torvalds int err;
9361da177e4SLinus Torvalds
9371da177e4SLinus Torvalds sb->s_blocksize = 1024;
9381da177e4SLinus Torvalds sb->s_blocksize_bits = 10;
9391da177e4SLinus Torvalds sb->s_magic = HOSTFS_SUPER_MAGIC;
9401da177e4SLinus Torvalds sb->s_op = &hostfs_sbops;
941b26d4cd3SAl Viro sb->s_d_op = &simple_dentry_operations;
942752fa51eSWolfgang Illmeyer sb->s_maxbytes = MAX_LFS_FILESIZE;
943ce72750fSSjoerd Simons err = super_setup_bdi(sb);
944ce72750fSSjoerd Simons if (err)
94574ce793bSMickaël Salaün return err;
9461da177e4SLinus Torvalds
947cd140ce9SHongbo Li root_inode = hostfs_iget(sb, fsi->host_root_path);
94874ce793bSMickaël Salaün if (IS_ERR(root_inode))
94974ce793bSMickaël Salaün return PTR_ERR(root_inode);
95052b209f7SAl Viro
9514754b825SAl Viro if (S_ISLNK(root_inode->i_mode)) {
95274ce793bSMickaël Salaün char *name;
95374ce793bSMickaël Salaün
95474ce793bSMickaël Salaün iput(root_inode);
955cd140ce9SHongbo Li name = follow_link(fsi->host_root_path);
95674ce793bSMickaël Salaün if (IS_ERR(name))
95774ce793bSMickaël Salaün return PTR_ERR(name);
95874ce793bSMickaël Salaün
95974ce793bSMickaël Salaün root_inode = hostfs_iget(sb, name);
96052b209f7SAl Viro kfree(name);
96174ce793bSMickaël Salaün if (IS_ERR(root_inode))
96274ce793bSMickaël Salaün return PTR_ERR(root_inode);
9634754b825SAl Viro }
9641da177e4SLinus Torvalds
96548fde701SAl Viro sb->s_root = d_make_root(root_inode);
9661da177e4SLinus Torvalds if (sb->s_root == NULL)
96774ce793bSMickaël Salaün return -ENOMEM;
9681da177e4SLinus Torvalds
969f1adc05eSJeff Dike return 0;
9701da177e4SLinus Torvalds }
9711da177e4SLinus Torvalds
972ef9ca17cSHongbo Li enum hostfs_parma {
973ef9ca17cSHongbo Li Opt_hostfs,
974ef9ca17cSHongbo Li };
975ef9ca17cSHongbo Li
976ef9ca17cSHongbo Li static const struct fs_parameter_spec hostfs_param_specs[] = {
977ef9ca17cSHongbo Li fsparam_string_empty("hostfs", Opt_hostfs),
978ef9ca17cSHongbo Li {}
979ef9ca17cSHongbo Li };
980ef9ca17cSHongbo Li
hostfs_parse_param(struct fs_context * fc,struct fs_parameter * param)981ef9ca17cSHongbo Li static int hostfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
982ef9ca17cSHongbo Li {
983ef9ca17cSHongbo Li struct hostfs_fs_info *fsi = fc->s_fs_info;
984ef9ca17cSHongbo Li struct fs_parse_result result;
985ef9ca17cSHongbo Li char *host_root;
986ef9ca17cSHongbo Li int opt;
987ef9ca17cSHongbo Li
988ef9ca17cSHongbo Li opt = fs_parse(fc, hostfs_param_specs, param, &result);
989ef9ca17cSHongbo Li if (opt < 0)
990ef9ca17cSHongbo Li return opt;
991ef9ca17cSHongbo Li
992ef9ca17cSHongbo Li switch (opt) {
993ef9ca17cSHongbo Li case Opt_hostfs:
994ef9ca17cSHongbo Li host_root = param->string;
995ef9ca17cSHongbo Li if (!*host_root)
996ef9ca17cSHongbo Li host_root = "";
997ef9ca17cSHongbo Li fsi->host_root_path =
998ef9ca17cSHongbo Li kasprintf(GFP_KERNEL, "%s/%s", root_ino, host_root);
999ef9ca17cSHongbo Li if (fsi->host_root_path == NULL)
1000ef9ca17cSHongbo Li return -ENOMEM;
1001ef9ca17cSHongbo Li break;
1002ef9ca17cSHongbo Li }
1003ef9ca17cSHongbo Li
1004ef9ca17cSHongbo Li return 0;
1005ef9ca17cSHongbo Li }
1006ef9ca17cSHongbo Li
hostfs_parse_monolithic(struct fs_context * fc,void * data)1007ef9ca17cSHongbo Li static int hostfs_parse_monolithic(struct fs_context *fc, void *data)
1008ef9ca17cSHongbo Li {
1009ef9ca17cSHongbo Li struct hostfs_fs_info *fsi = fc->s_fs_info;
1010ef9ca17cSHongbo Li char *host_root = (char *)data;
1011ef9ca17cSHongbo Li
1012ef9ca17cSHongbo Li /* NULL is printed as '(null)' by printf(): avoid that. */
1013ef9ca17cSHongbo Li if (host_root == NULL)
1014ef9ca17cSHongbo Li host_root = "";
1015ef9ca17cSHongbo Li
1016ef9ca17cSHongbo Li fsi->host_root_path =
1017ef9ca17cSHongbo Li kasprintf(GFP_KERNEL, "%s/%s", root_ino, host_root);
1018ef9ca17cSHongbo Li if (fsi->host_root_path == NULL)
1019ef9ca17cSHongbo Li return -ENOMEM;
1020ef9ca17cSHongbo Li
1021ef9ca17cSHongbo Li return 0;
1022ef9ca17cSHongbo Li }
1023ef9ca17cSHongbo Li
hostfs_fc_get_tree(struct fs_context * fc)1024cd140ce9SHongbo Li static int hostfs_fc_get_tree(struct fs_context *fc)
10251da177e4SLinus Torvalds {
1026cd140ce9SHongbo Li return get_tree_nodev(fc, hostfs_fill_super);
1027cd140ce9SHongbo Li }
1028cd140ce9SHongbo Li
hostfs_fc_free(struct fs_context * fc)1029cd140ce9SHongbo Li static void hostfs_fc_free(struct fs_context *fc)
1030cd140ce9SHongbo Li {
1031cd140ce9SHongbo Li struct hostfs_fs_info *fsi = fc->s_fs_info;
1032cd140ce9SHongbo Li
1033cd140ce9SHongbo Li if (!fsi)
1034cd140ce9SHongbo Li return;
1035cd140ce9SHongbo Li
1036cd140ce9SHongbo Li kfree(fsi->host_root_path);
1037cd140ce9SHongbo Li kfree(fsi);
1038cd140ce9SHongbo Li }
1039cd140ce9SHongbo Li
1040cd140ce9SHongbo Li static const struct fs_context_operations hostfs_context_ops = {
1041ef9ca17cSHongbo Li .parse_monolithic = hostfs_parse_monolithic,
1042ef9ca17cSHongbo Li .parse_param = hostfs_parse_param,
1043cd140ce9SHongbo Li .get_tree = hostfs_fc_get_tree,
1044cd140ce9SHongbo Li .free = hostfs_fc_free,
1045cd140ce9SHongbo Li };
1046cd140ce9SHongbo Li
hostfs_init_fs_context(struct fs_context * fc)1047cd140ce9SHongbo Li static int hostfs_init_fs_context(struct fs_context *fc)
1048cd140ce9SHongbo Li {
1049cd140ce9SHongbo Li struct hostfs_fs_info *fsi;
1050cd140ce9SHongbo Li
1051cd140ce9SHongbo Li fsi = kzalloc(sizeof(*fsi), GFP_KERNEL);
1052cd140ce9SHongbo Li if (!fsi)
1053cd140ce9SHongbo Li return -ENOMEM;
1054cd140ce9SHongbo Li
1055cd140ce9SHongbo Li fc->s_fs_info = fsi;
1056cd140ce9SHongbo Li fc->ops = &hostfs_context_ops;
1057cd140ce9SHongbo Li return 0;
10581da177e4SLinus Torvalds }
10591da177e4SLinus Torvalds
hostfs_kill_sb(struct super_block * s)1060601d2c38SAl Viro static void hostfs_kill_sb(struct super_block *s)
1061601d2c38SAl Viro {
1062601d2c38SAl Viro kill_anon_super(s);
1063601d2c38SAl Viro kfree(s->s_fs_info);
1064601d2c38SAl Viro }
1065601d2c38SAl Viro
10661da177e4SLinus Torvalds static struct file_system_type hostfs_type = {
10671da177e4SLinus Torvalds .owner = THIS_MODULE,
10681da177e4SLinus Torvalds .name = "hostfs",
1069cd140ce9SHongbo Li .init_fs_context = hostfs_init_fs_context,
1070601d2c38SAl Viro .kill_sb = hostfs_kill_sb,
10711da177e4SLinus Torvalds .fs_flags = 0,
10721da177e4SLinus Torvalds };
10733e64fe5bSEric W. Biederman MODULE_ALIAS_FS("hostfs");
10741da177e4SLinus Torvalds
init_hostfs(void)10751da177e4SLinus Torvalds static int __init init_hostfs(void)
10761da177e4SLinus Torvalds {
1077a15f1e41SJohannes Berg hostfs_inode_cache = KMEM_CACHE(hostfs_inode_info, 0);
1078a15f1e41SJohannes Berg if (!hostfs_inode_cache)
1079a15f1e41SJohannes Berg return -ENOMEM;
1080f1adc05eSJeff Dike return register_filesystem(&hostfs_type);
10811da177e4SLinus Torvalds }
10821da177e4SLinus Torvalds
exit_hostfs(void)10831da177e4SLinus Torvalds static void __exit exit_hostfs(void)
10841da177e4SLinus Torvalds {
10851da177e4SLinus Torvalds unregister_filesystem(&hostfs_type);
1086a15f1e41SJohannes Berg kmem_cache_destroy(hostfs_inode_cache);
10871da177e4SLinus Torvalds }
10881da177e4SLinus Torvalds
10891da177e4SLinus Torvalds module_init(init_hostfs)
10901da177e4SLinus Torvalds module_exit(exit_hostfs)
1091be5d511dSJeff Johnson MODULE_DESCRIPTION("User-Mode Linux Host filesystem");
10921da177e4SLinus Torvalds MODULE_LICENSE("GPL");
1093