| /* |
| * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) |
| * Licensed under the GPL |
| * |
| * Ported the filesystem routines to 2.5. |
| * 2003-02-10 Petr Baudis <pasky@ucw.cz> |
| */ |
| |
| #include <linux/stddef.h> |
| #include <linux/fs.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/pagemap.h> |
| #include <linux/blkdev.h> |
| #include <linux/list.h> |
| #include <linux/statfs.h> |
| #include <linux/kdev_t.h> |
| #include <asm/uaccess.h> |
| #include "hostfs.h" |
| #include "kern_util.h" |
| #include "kern.h" |
| #include "user_util.h" |
| #include "init.h" |
| |
| struct hostfs_inode_info { |
| char *host_filename; |
| int fd; |
| int mode; |
| struct inode vfs_inode; |
| }; |
| |
| static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) |
| { |
| return(list_entry(inode, struct hostfs_inode_info, vfs_inode)); |
| } |
| |
| #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_dentry->d_inode) |
| |
| int hostfs_d_delete(struct dentry *dentry) |
| { |
| return(1); |
| } |
| |
| struct dentry_operations hostfs_dentry_ops = { |
| .d_delete = hostfs_d_delete, |
| }; |
| |
| /* Changed in hostfs_args before the kernel starts running */ |
| static char *root_ino = "/"; |
| static int append = 0; |
| |
| #define HOSTFS_SUPER_MAGIC 0x00c0ffee |
| |
| static struct inode_operations hostfs_iops; |
| static struct inode_operations hostfs_dir_iops; |
| static struct address_space_operations hostfs_link_aops; |
| |
| #ifndef MODULE |
| static int __init hostfs_args(char *options, int *add) |
| { |
| char *ptr; |
| |
| ptr = strchr(options, ','); |
| if(ptr != NULL) |
| *ptr++ = '\0'; |
| if(*options != '\0') |
| root_ino = options; |
| |
| options = ptr; |
| while(options){ |
| ptr = strchr(options, ','); |
| if(ptr != NULL) |
| *ptr++ = '\0'; |
| if(*options != '\0'){ |
| if(!strcmp(options, "append")) |
| append = 1; |
| else printf("hostfs_args - unsupported option - %s\n", |
| options); |
| } |
| options = ptr; |
| } |
| return(0); |
| } |
| |
| __uml_setup("hostfs=", hostfs_args, |
| "hostfs=<root dir>,<flags>,...\n" |
| " This is used to set hostfs parameters. The root directory argument\n" |
| " is used to confine all hostfs mounts to within the specified directory\n" |
| " tree on the host. If this isn't specified, then a user inside UML can\n" |
| " mount anything on the host that's accessible to the user that's running\n" |
| " it.\n" |
| " The only flag currently supported is 'append', which specifies that all\n" |
| " files opened by hostfs will be opened in append mode.\n\n" |
| ); |
| #endif |
| |
| static char *dentry_name(struct dentry *dentry, int extra) |
| { |
| struct dentry *parent; |
| char *root, *name; |
| int len; |
| |
| len = 0; |
| parent = dentry; |
| while(parent->d_parent != parent){ |
| len += parent->d_name.len + 1; |
| parent = parent->d_parent; |
| } |
| |
| root = HOSTFS_I(parent->d_inode)->host_filename; |
| len += strlen(root); |
| name = kmalloc(len + extra + 1, GFP_KERNEL); |
| if(name == NULL) return(NULL); |
| |
| name[len] = '\0'; |
| parent = dentry; |
| while(parent->d_parent != parent){ |
| len -= parent->d_name.len + 1; |
| name[len] = '/'; |
| strncpy(&name[len + 1], parent->d_name.name, |
| parent->d_name.len); |
| parent = parent->d_parent; |
| } |
| strncpy(name, root, strlen(root)); |
| return(name); |
| } |
| |
| static char *inode_name(struct inode *ino, int extra) |
| { |
| struct dentry *dentry; |
| |
| dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); |
| return(dentry_name(dentry, extra)); |
| } |
| |
| static int read_name(struct inode *ino, char *name) |
| { |
| /* The non-int inode fields are copied into ints by stat_file and |
| * then copied into the inode because passing the actual pointers |
| * in and having them treated as int * breaks on big-endian machines |
| */ |
| int err; |
| int i_mode, i_nlink, i_blksize; |
| unsigned long long i_size; |
| unsigned long long i_ino; |
| unsigned long long i_blocks; |
| |
| err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, |
| &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, |
| &ino->i_ctime, &i_blksize, &i_blocks); |
| if(err) |
| return(err); |
| |
| ino->i_ino = i_ino; |
| ino->i_mode = i_mode; |
| ino->i_nlink = i_nlink; |
| ino->i_size = i_size; |
| ino->i_blksize = i_blksize; |
| ino->i_blocks = i_blocks; |
| return(0); |
| } |
| |
| static char *follow_link(char *link) |
| { |
| int len, n; |
| char *name, *resolved, *end; |
| |
| len = 64; |
| while(1){ |
| n = -ENOMEM; |
| name = kmalloc(len, GFP_KERNEL); |
| if(name == NULL) |
| goto out; |
| |
| n = do_readlink(link, name, len); |
| if(n < len) |
| break; |
| len *= 2; |
| kfree(name); |
| } |
| if(n < 0) |
| goto out_free; |
| |
| if(*name == '/') |
| return(name); |
| |
| end = strrchr(link, '/'); |
| if(end == NULL) |
| return(name); |
| |
| *(end + 1) = '\0'; |
| len = strlen(link) + strlen(name) + 1; |
| |
| resolved = kmalloc(len, GFP_KERNEL); |
| if(resolved == NULL){ |
| n = -ENOMEM; |
| goto out_free; |
| } |
| |
| sprintf(resolved, "%s%s", link, name); |
| kfree(name); |
| kfree(link); |
| return(resolved); |
| |
| out_free: |
| kfree(name); |
| out: |
| return(ERR_PTR(n)); |
| } |
| |
| static int read_inode(struct inode *ino) |
| { |
| char *name; |
| int err = 0; |
| |
| /* Unfortunately, we are called from iget() when we don't have a dentry |
| * allocated yet. |
| */ |
| if(list_empty(&ino->i_dentry)) |
| goto out; |
| |
| err = -ENOMEM; |
| name = inode_name(ino, 0); |
| if(name == NULL) |
| goto out; |
| |
| if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){ |
| name = follow_link(name); |
| if(IS_ERR(name)){ |
| err = PTR_ERR(name); |
| goto out; |
| } |
| } |
| |
| err = read_name(ino, name); |
| kfree(name); |
| out: |
| return(err); |
| } |
| |
| int hostfs_statfs(struct super_block *sb, struct kstatfs *sf) |
| { |
| /* do_statfs uses struct statfs64 internally, but the linux kernel |
| * struct statfs still has 32-bit versions for most of these fields, |
| * so we convert them here |
| */ |
| int err; |
| long long f_blocks; |
| long long f_bfree; |
| long long f_bavail; |
| long long f_files; |
| long long f_ffree; |
| |
| err = do_statfs(HOSTFS_I(sb->s_root->d_inode)->host_filename, |
| &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
| &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), |
| &sf->f_namelen, sf->f_spare); |
| if(err) return(err); |
| sf->f_blocks = f_blocks; |
| sf->f_bfree = f_bfree; |
| sf->f_bavail = f_bavail; |
| sf->f_files = f_files; |
| sf->f_ffree = f_ffree; |
| sf->f_type = HOSTFS_SUPER_MAGIC; |
| return(0); |
| } |
| |
| static struct inode *hostfs_alloc_inode(struct super_block *sb) |
| { |
| struct hostfs_inode_info *hi; |
| |
| hi = kmalloc(sizeof(*hi), GFP_KERNEL); |
| if(hi == NULL) |
| return(NULL); |
| |
| *hi = ((struct hostfs_inode_info) { .host_filename = NULL, |
| .fd = -1, |
| .mode = 0 }); |
| inode_init_once(&hi->vfs_inode); |
| return(&hi->vfs_inode); |
| } |
| |
| static void hostfs_delete_inode(struct inode *inode) |
| { |
| truncate_inode_pages(&inode->i_data, 0); |
| if(HOSTFS_I(inode)->fd != -1) { |
| close_file(&HOSTFS_I(inode)->fd); |
| HOSTFS_I(inode)->fd = -1; |
| } |
| clear_inode(inode); |
| } |
| |
| static void hostfs_destroy_inode(struct inode *inode) |
| { |
| kfree(HOSTFS_I(inode)->host_filename); |
| |
| /*XXX: This should not happen, probably. The check is here for |
| * additional safety.*/ |
| if(HOSTFS_I(inode)->fd != -1) { |
| close_file(&HOSTFS_I(inode)->fd); |
| printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); |
| } |
| |
| kfree(HOSTFS_I(inode)); |
| } |
| |
| static void hostfs_read_inode(struct inode *inode) |
| { |
| read_inode(inode); |
| } |
| |
| static struct super_operations hostfs_sbops = { |
| .alloc_inode = hostfs_alloc_inode, |
| .drop_inode = generic_delete_inode, |
| .delete_inode = hostfs_delete_inode, |
| .destroy_inode = hostfs_destroy_inode, |
| .read_inode = hostfs_read_inode, |
| .statfs = hostfs_statfs, |
| }; |
| |
| int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) |
| { |
| void *dir; |
| char *name; |
| unsigned long long next, ino; |
| int error, len; |
| |
| name = dentry_name(file->f_dentry, 0); |
| if(name == NULL) return(-ENOMEM); |
| dir = open_dir(name, &error); |
| kfree(name); |
| if(dir == NULL) return(-error); |
| next = file->f_pos; |
| while((name = read_dir(dir, &next, &ino, &len)) != NULL){ |
| error = (*filldir)(ent, name, len, file->f_pos, |
| ino, DT_UNKNOWN); |
| if(error) break; |
| file->f_pos = next; |
| } |
| close_dir(dir); |
| return(0); |
| } |
| |
| int hostfs_file_open(struct inode *ino, struct file *file) |
| { |
| char *name; |
| int mode = 0, r = 0, w = 0, fd; |
| |
| mode = file->f_mode & (FMODE_READ | FMODE_WRITE); |
| if((mode & HOSTFS_I(ino)->mode) == mode) |
| return(0); |
| |
| /* The file may already have been opened, but with the wrong access, |
| * so this resets things and reopens the file with the new access. |
| */ |
| if(HOSTFS_I(ino)->fd != -1){ |
| close_file(&HOSTFS_I(ino)->fd); |
| HOSTFS_I(ino)->fd = -1; |
| } |
| |
| HOSTFS_I(ino)->mode |= mode; |
| if(HOSTFS_I(ino)->mode & FMODE_READ) |
| r = 1; |
| if(HOSTFS_I(ino)->mode & FMODE_WRITE) |
| w = 1; |
| if(w) |
| r = 1; |
| |
| name = dentry_name(file->f_dentry, 0); |
| if(name == NULL) |
| return(-ENOMEM); |
| |
| fd = open_file(name, r, w, append); |
| kfree(name); |
| if(fd < 0) return(fd); |
| FILE_HOSTFS_I(file)->fd = fd; |
| |
| return(0); |
| } |
| |
| int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) |
| { |
| return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
| } |
| |
| static struct file_operations hostfs_file_fops = { |
| .llseek = generic_file_llseek, |
| .read = generic_file_read, |
| .sendfile = generic_file_sendfile, |
| .aio_read = generic_file_aio_read, |
| .aio_write = generic_file_aio_write, |
| .readv = generic_file_readv, |
| .writev = generic_file_writev, |
| .write = generic_file_write, |
| .mmap = generic_file_mmap, |
| .open = hostfs_file_open, |
| .release = NULL, |
| .fsync = hostfs_fsync, |
| }; |
| |
| static struct file_operations hostfs_dir_fops = { |
| .llseek = generic_file_llseek, |
| .readdir = hostfs_readdir, |
| .read = generic_read_dir, |
| }; |
| |
| int hostfs_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| char *buffer; |
| unsigned long long base; |
| int count = PAGE_CACHE_SIZE; |
| int end_index = inode->i_size >> PAGE_CACHE_SHIFT; |
| int err; |
| |
| if (page->index >= end_index) |
| count = inode->i_size & (PAGE_CACHE_SIZE-1); |
| |
| buffer = kmap(page); |
| base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; |
| |
| err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); |
| if(err != count){ |
| ClearPageUptodate(page); |
| goto out; |
| } |
| |
| if (base > inode->i_size) |
| inode->i_size = base; |
| |
| if (PageError(page)) |
| ClearPageError(page); |
| err = 0; |
| |
| out: |
| kunmap(page); |
| |
| unlock_page(page); |
| return err; |
| } |
| |
| int hostfs_readpage(struct file *file, struct page *page) |
| { |
| char *buffer; |
| long long start; |
| int err = 0; |
| |
| start = (long long) page->index << PAGE_CACHE_SHIFT; |
| buffer = kmap(page); |
| err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, |
| PAGE_CACHE_SIZE); |
| if(err < 0) goto out; |
| |
| memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); |
| |
| flush_dcache_page(page); |
| SetPageUptodate(page); |
| if (PageError(page)) ClearPageError(page); |
| err = 0; |
| out: |
| kunmap(page); |
| unlock_page(page); |
| return(err); |
| } |
| |
| int hostfs_prepare_write(struct file *file, struct page *page, |
| unsigned int from, unsigned int to) |
| { |
| char *buffer; |
| long long start, tmp; |
| int err; |
| |
| start = (long long) page->index << PAGE_CACHE_SHIFT; |
| buffer = kmap(page); |
| if(from != 0){ |
| tmp = start; |
| err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer, |
| from); |
| if(err < 0) goto out; |
| } |
| if(to != PAGE_CACHE_SIZE){ |
| start += to; |
| err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to, |
| PAGE_CACHE_SIZE - to); |
| if(err < 0) goto out; |
| } |
| err = 0; |
| out: |
| kunmap(page); |
| return(err); |
| } |
| |
| int hostfs_commit_write(struct file *file, struct page *page, unsigned from, |
| unsigned to) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| char *buffer; |
| long long start; |
| int err = 0; |
| |
| start = (long long) (page->index << PAGE_CACHE_SHIFT) + from; |
| buffer = kmap(page); |
| err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from, |
| to - from); |
| if(err > 0) err = 0; |
| if(!err && (start > inode->i_size)) |
| inode->i_size = start; |
| |
| kunmap(page); |
| return(err); |
| } |
| |
| static struct address_space_operations hostfs_aops = { |
| .writepage = hostfs_writepage, |
| .readpage = hostfs_readpage, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .prepare_write = hostfs_prepare_write, |
| .commit_write = hostfs_commit_write |
| }; |
| |
| static int init_inode(struct inode *inode, struct dentry *dentry) |
| { |
| char *name; |
| int type, err = -ENOMEM; |
| int maj, min; |
| dev_t rdev = 0; |
| |
| if(dentry){ |
| name = dentry_name(dentry, 0); |
| if(name == NULL) |
| goto out; |
| type = file_type(name, &maj, &min); |
| /*Reencode maj and min with the kernel encoding.*/ |
| rdev = MKDEV(maj, min); |
| kfree(name); |
| } |
| else type = OS_TYPE_DIR; |
| |
| err = 0; |
| if(type == OS_TYPE_SYMLINK) |
| inode->i_op = &page_symlink_inode_operations; |
| else if(type == OS_TYPE_DIR) |
| inode->i_op = &hostfs_dir_iops; |
| else inode->i_op = &hostfs_iops; |
| |
| if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; |
| else inode->i_fop = &hostfs_file_fops; |
| |
| if(type == OS_TYPE_SYMLINK) |
| inode->i_mapping->a_ops = &hostfs_link_aops; |
| else inode->i_mapping->a_ops = &hostfs_aops; |
| |
| switch (type) { |
| case OS_TYPE_CHARDEV: |
| init_special_inode(inode, S_IFCHR, rdev); |
| break; |
| case OS_TYPE_BLOCKDEV: |
| init_special_inode(inode, S_IFBLK, rdev); |
| break; |
| case OS_TYPE_FIFO: |
| init_special_inode(inode, S_IFIFO, 0); |
| break; |
| case OS_TYPE_SOCK: |
| init_special_inode(inode, S_IFSOCK, 0); |
| break; |
| } |
| out: |
| return(err); |
| } |
| |
| int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, |
| struct nameidata *nd) |
| { |
| struct inode *inode; |
| char *name; |
| int error, fd; |
| |
| error = -ENOMEM; |
| inode = iget(dir->i_sb, 0); |
| if(inode == NULL) goto out; |
| |
| error = init_inode(inode, dentry); |
| if(error) |
| goto out_put; |
| |
| error = -ENOMEM; |
| name = dentry_name(dentry, 0); |
| if(name == NULL) |
| goto out_put; |
| |
| fd = file_create(name, |
| mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, |
| mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, |
| mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); |
| if(fd < 0) |
| error = fd; |
| else error = read_name(inode, name); |
| |
| kfree(name); |
| if(error) |
| goto out_put; |
| |
| HOSTFS_I(inode)->fd = fd; |
| HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; |
| d_instantiate(dentry, inode); |
| return(0); |
| |
| out_put: |
| iput(inode); |
| out: |
| return(error); |
| } |
| |
| struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, |
| struct nameidata *nd) |
| { |
| struct inode *inode; |
| char *name; |
| int err; |
| |
| err = -ENOMEM; |
| inode = iget(ino->i_sb, 0); |
| if(inode == NULL) |
| goto out; |
| |
| err = init_inode(inode, dentry); |
| if(err) |
| goto out_put; |
| |
| err = -ENOMEM; |
| name = dentry_name(dentry, 0); |
| if(name == NULL) |
| goto out_put; |
| |
| err = read_name(inode, name); |
| kfree(name); |
| if(err == -ENOENT){ |
| iput(inode); |
| inode = NULL; |
| } |
| else if(err) |
| goto out_put; |
| |
| d_add(dentry, inode); |
| dentry->d_op = &hostfs_dentry_ops; |
| return(NULL); |
| |
| out_put: |
| iput(inode); |
| out: |
| return(ERR_PTR(err)); |
| } |
| |
| static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) |
| { |
| char *file; |
| int len; |
| |
| file = inode_name(ino, dentry->d_name.len + 1); |
| if(file == NULL) return(NULL); |
| strcat(file, "/"); |
| len = strlen(file); |
| strncat(file, dentry->d_name.name, dentry->d_name.len); |
| file[len + dentry->d_name.len] = '\0'; |
| return(file); |
| } |
| |
| int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
| { |
| char *from_name, *to_name; |
| int err; |
| |
| if((from_name = inode_dentry_name(ino, from)) == NULL) |
| return(-ENOMEM); |
| to_name = dentry_name(to, 0); |
| if(to_name == NULL){ |
| kfree(from_name); |
| return(-ENOMEM); |
| } |
| err = link_file(to_name, from_name); |
| kfree(from_name); |
| kfree(to_name); |
| return(err); |
| } |
| |
| int hostfs_unlink(struct inode *ino, struct dentry *dentry) |
| { |
| char *file; |
| int err; |
| |
| if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); |
| if(append) |
| return(-EPERM); |
| |
| err = unlink_file(file); |
| kfree(file); |
| return(err); |
| } |
| |
| int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) |
| { |
| char *file; |
| int err; |
| |
| if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); |
| err = make_symlink(file, to); |
| kfree(file); |
| return(err); |
| } |
| |
| int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) |
| { |
| char *file; |
| int err; |
| |
| if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); |
| err = do_mkdir(file, mode); |
| kfree(file); |
| return(err); |
| } |
| |
| int hostfs_rmdir(struct inode *ino, struct dentry *dentry) |
| { |
| char *file; |
| int err; |
| |
| if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); |
| err = do_rmdir(file); |
| kfree(file); |
| return(err); |
| } |
| |
| int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) |
| { |
| struct inode *inode; |
| char *name; |
| int err = -ENOMEM; |
| |
| inode = iget(dir->i_sb, 0); |
| if(inode == NULL) |
| goto out; |
| |
| err = init_inode(inode, dentry); |
| if(err) |
| goto out_put; |
| |
| err = -ENOMEM; |
| name = dentry_name(dentry, 0); |
| if(name == NULL) |
| goto out_put; |
| |
| init_special_inode(inode, mode, dev); |
| err = do_mknod(name, mode, dev); |
| if(err) |
| goto out_free; |
| |
| err = read_name(inode, name); |
| kfree(name); |
| if(err) |
| goto out_put; |
| |
| d_instantiate(dentry, inode); |
| return(0); |
| |
| out_free: |
| kfree(name); |
| out_put: |
| iput(inode); |
| out: |
| return(err); |
| } |
| |
| int hostfs_rename(struct inode *from_ino, struct dentry *from, |
| struct inode *to_ino, struct dentry *to) |
| { |
| char *from_name, *to_name; |
| int err; |
| |
| if((from_name = inode_dentry_name(from_ino, from)) == NULL) |
| return(-ENOMEM); |
| if((to_name = inode_dentry_name(to_ino, to)) == NULL){ |
| kfree(from_name); |
| return(-ENOMEM); |
| } |
| err = rename_file(from_name, to_name); |
| kfree(from_name); |
| kfree(to_name); |
| return(err); |
| } |
| |
| int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
| { |
| char *name; |
| int r = 0, w = 0, x = 0, err; |
| |
| if (desired & MAY_READ) r = 1; |
| if (desired & MAY_WRITE) w = 1; |
| if (desired & MAY_EXEC) x = 1; |
| name = inode_name(ino, 0); |
| if (name == NULL) return(-ENOMEM); |
| |
| if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || |
| S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
| err = 0; |
| else |
| err = access_file(name, r, w, x); |
| kfree(name); |
| if(!err) |
| err = generic_permission(ino, desired, NULL); |
| return err; |
| } |
| |
| int hostfs_setattr(struct dentry *dentry, struct iattr *attr) |
| { |
| struct hostfs_iattr attrs; |
| char *name; |
| int err; |
| |
| err = inode_change_ok(dentry->d_inode, attr); |
| if (err) |
| return err; |
| |
| if(append) |
| attr->ia_valid &= ~ATTR_SIZE; |
| |
| attrs.ia_valid = 0; |
| if(attr->ia_valid & ATTR_MODE){ |
| attrs.ia_valid |= HOSTFS_ATTR_MODE; |
| attrs.ia_mode = attr->ia_mode; |
| } |
| if(attr->ia_valid & ATTR_UID){ |
| attrs.ia_valid |= HOSTFS_ATTR_UID; |
| attrs.ia_uid = attr->ia_uid; |
| } |
| if(attr->ia_valid & ATTR_GID){ |
| attrs.ia_valid |= HOSTFS_ATTR_GID; |
| attrs.ia_gid = attr->ia_gid; |
| } |
| if(attr->ia_valid & ATTR_SIZE){ |
| attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
| attrs.ia_size = attr->ia_size; |
| } |
| if(attr->ia_valid & ATTR_ATIME){ |
| attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
| attrs.ia_atime = attr->ia_atime; |
| } |
| if(attr->ia_valid & ATTR_MTIME){ |
| attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
| attrs.ia_mtime = attr->ia_mtime; |
| } |
| if(attr->ia_valid & ATTR_CTIME){ |
| attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
| attrs.ia_ctime = attr->ia_ctime; |
| } |
| if(attr->ia_valid & ATTR_ATIME_SET){ |
| attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
| } |
| if(attr->ia_valid & ATTR_MTIME_SET){ |
| attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
| } |
| name = dentry_name(dentry, 0); |
| if(name == NULL) return(-ENOMEM); |
| err = set_attr(name, &attrs); |
| kfree(name); |
| if(err) |
| return(err); |
| |
| return(inode_setattr(dentry->d_inode, attr)); |
| } |
| |
| int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| struct kstat *stat) |
| { |
| generic_fillattr(dentry->d_inode, stat); |
| return(0); |
| } |
| |
| static struct inode_operations hostfs_iops = { |
| .create = hostfs_create, |
| .link = hostfs_link, |
| .unlink = hostfs_unlink, |
| .symlink = hostfs_symlink, |
| .mkdir = hostfs_mkdir, |
| .rmdir = hostfs_rmdir, |
| .mknod = hostfs_mknod, |
| .rename = hostfs_rename, |
| .permission = hostfs_permission, |
| .setattr = hostfs_setattr, |
| .getattr = hostfs_getattr, |
| }; |
| |
| static struct inode_operations hostfs_dir_iops = { |
| .create = hostfs_create, |
| .lookup = hostfs_lookup, |
| .link = hostfs_link, |
| .unlink = hostfs_unlink, |
| .symlink = hostfs_symlink, |
| .mkdir = hostfs_mkdir, |
| .rmdir = hostfs_rmdir, |
| .mknod = hostfs_mknod, |
| .rename = hostfs_rename, |
| .permission = hostfs_permission, |
| .setattr = hostfs_setattr, |
| .getattr = hostfs_getattr, |
| }; |
| |
| int hostfs_link_readpage(struct file *file, struct page *page) |
| { |
| char *buffer, *name; |
| int err; |
| |
| buffer = kmap(page); |
| name = inode_name(page->mapping->host, 0); |
| if(name == NULL) return(-ENOMEM); |
| err = do_readlink(name, buffer, PAGE_CACHE_SIZE); |
| kfree(name); |
| if(err == PAGE_CACHE_SIZE) |
| err = -E2BIG; |
| else if(err > 0){ |
| flush_dcache_page(page); |
| SetPageUptodate(page); |
| if (PageError(page)) ClearPageError(page); |
| err = 0; |
| } |
| kunmap(page); |
| unlock_page(page); |
| return(err); |
| } |
| |
| static struct address_space_operations hostfs_link_aops = { |
| .readpage = hostfs_link_readpage, |
| }; |
| |
| static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) |
| { |
| struct inode *root_inode; |
| char *name, *data = d; |
| int err; |
| |
| sb->s_blocksize = 1024; |
| sb->s_blocksize_bits = 10; |
| sb->s_magic = HOSTFS_SUPER_MAGIC; |
| sb->s_op = &hostfs_sbops; |
| |
| if((data == NULL) || (*data == '\0')) |
| data = root_ino; |
| |
| err = -ENOMEM; |
| name = kmalloc(strlen(data) + 1, GFP_KERNEL); |
| if(name == NULL) |
| goto out; |
| |
| strcpy(name, data); |
| |
| root_inode = iget(sb, 0); |
| if(root_inode == NULL) |
| goto out_free; |
| |
| err = init_inode(root_inode, NULL); |
| if(err) |
| goto out_put; |
| |
| HOSTFS_I(root_inode)->host_filename = name; |
| |
| err = -ENOMEM; |
| sb->s_root = d_alloc_root(root_inode); |
| if(sb->s_root == NULL) |
| goto out_put; |
| |
| err = read_inode(root_inode); |
| if(err){ |
| /* No iput in this case because the dput does that for us */ |
| dput(sb->s_root); |
| sb->s_root = NULL; |
| goto out_free; |
| } |
| |
| return(0); |
| |
| out_put: |
| iput(root_inode); |
| out_free: |
| kfree(name); |
| out: |
| return(err); |
| } |
| |
| static struct super_block *hostfs_read_sb(struct file_system_type *type, |
| int flags, const char *dev_name, |
| void *data) |
| { |
| return(get_sb_nodev(type, flags, data, hostfs_fill_sb_common)); |
| } |
| |
| static struct file_system_type hostfs_type = { |
| .owner = THIS_MODULE, |
| .name = "hostfs", |
| .get_sb = hostfs_read_sb, |
| .kill_sb = kill_anon_super, |
| .fs_flags = 0, |
| }; |
| |
| static int __init init_hostfs(void) |
| { |
| return(register_filesystem(&hostfs_type)); |
| } |
| |
| static void __exit exit_hostfs(void) |
| { |
| unregister_filesystem(&hostfs_type); |
| } |
| |
| module_init(init_hostfs) |
| module_exit(exit_hostfs) |
| MODULE_LICENSE("GPL"); |
| |
| /* |
| * Overrides for Emacs so that we follow Linus's tabbing style. |
| * Emacs will notice this stuff at the end of the file and automatically |
| * adjust the settings for this buffer only. This must remain at the end |
| * of the file. |
| * --------------------------------------------------------------------------- |
| * Local variables: |
| * c-file-style: "linux" |
| * End: |
| */ |