/* * linux/fs/super.c * * Copyright (C) 1991, 1992 Linus Torvalds * * super.c contains code to handle: - mount structures * - super-block tables. * - mount systemcall * - umount systemcall * * Added options to /proc/mounts * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996. * * GK 2/5/95 - Changed to support mounting the root fs via NFS * * Added kerneld support: Jacques Gelinas and Bjorn Ekwall * Added change_root: Werner Almesberger & Hans Lermen, Feb '96 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_KERNELD #include #endif #include #include #include extern void wait_for_keypress(void); extern struct file_operations * get_blkfops(unsigned int major); extern int root_mountflags; static int do_remount_sb(struct super_block *sb, int flags, char * data); /* this is initialized in init/main.c */ kdev_t ROOT_DEV; struct super_block super_blocks[NR_SUPER]; static struct file_system_type *file_systems = (struct file_system_type *) NULL; static struct vfsmount *vfsmntlist = (struct vfsmount *) NULL, *vfsmnttail = (struct vfsmount *) NULL, *mru_vfsmnt = (struct vfsmount *) NULL; /* * This part handles the management of the list of mounted filesystems. */ struct vfsmount *lookup_vfsmnt(kdev_t dev) { struct vfsmount *lptr; if (vfsmntlist == (struct vfsmount *)NULL) return ((struct vfsmount *)NULL); if (mru_vfsmnt != (struct vfsmount *)NULL && mru_vfsmnt->mnt_dev == dev) return (mru_vfsmnt); for (lptr = vfsmntlist; lptr != (struct vfsmount *)NULL; lptr = lptr->mnt_next) if (lptr->mnt_dev == dev) { mru_vfsmnt = lptr; return (lptr); } return ((struct vfsmount *)NULL); /* NOTREACHED */ } struct vfsmount *add_vfsmnt(kdev_t dev, const char *dev_name, const char *dir_name) { struct vfsmount *lptr; char *tmp; lptr = (struct vfsmount *)kmalloc(sizeof(struct vfsmount), GFP_KERNEL); if (!lptr) return NULL; memset(lptr, 0, sizeof(struct vfsmount)); lptr->mnt_dev = dev; sema_init(&lptr->mnt_sem, 1); if (dev_name && !getname(dev_name, &tmp)) { if ((lptr->mnt_devname = (char *) kmalloc(strlen(tmp)+1, GFP_KERNEL)) != (char *)NULL) strcpy(lptr->mnt_devname, tmp); putname(tmp); } if (dir_name && !getname(dir_name, &tmp)) { if ((lptr->mnt_dirname = (char *) kmalloc(strlen(tmp)+1, GFP_KERNEL)) != (char *)NULL) strcpy(lptr->mnt_dirname, tmp); putname(tmp); } if (vfsmntlist == (struct vfsmount *)NULL) { vfsmntlist = vfsmnttail = lptr; } else { vfsmnttail->mnt_next = lptr; vfsmnttail = lptr; } return (lptr); } void remove_vfsmnt(kdev_t dev) { struct vfsmount *lptr, *tofree; if (vfsmntlist == (struct vfsmount *)NULL) return; lptr = vfsmntlist; if (lptr->mnt_dev == dev) { tofree = lptr; vfsmntlist = lptr->mnt_next; if (vfsmnttail->mnt_dev == dev) vfsmnttail = vfsmntlist; } else { while (lptr->mnt_next != (struct vfsmount *)NULL) { if (lptr->mnt_next->mnt_dev == dev) break; lptr = lptr->mnt_next; } tofree = lptr->mnt_next; if (tofree == (struct vfsmount *)NULL) return; lptr->mnt_next = lptr->mnt_next->mnt_next; if (vfsmnttail->mnt_dev == dev) vfsmnttail = lptr; } if (tofree == mru_vfsmnt) mru_vfsmnt = NULL; kfree(tofree->mnt_devname); kfree(tofree->mnt_dirname); kfree_s(tofree, sizeof(struct vfsmount)); } int register_filesystem(struct file_system_type * fs) { struct file_system_type ** tmp; if (!fs) return -EINVAL; if (fs->next) return -EBUSY; tmp = &file_systems; while (*tmp) { if (strcmp((*tmp)->name, fs->name) == 0) return -EBUSY; tmp = &(*tmp)->next; } *tmp = fs; return 0; } #ifdef CONFIG_MODULES int unregister_filesystem(struct file_system_type * fs) { struct file_system_type ** tmp; tmp = &file_systems; while (*tmp) { if (fs == *tmp) { *tmp = fs->next; fs->next = NULL; return 0; } tmp = &(*tmp)->next; } return -EINVAL; } #endif static int fs_index(const char * __name) { struct file_system_type * tmp; char * name; int err, index; err = getname(__name, &name); if (err) return err; index = 0; for (tmp = file_systems ; tmp ; tmp = tmp->next) { if (strcmp(tmp->name, name) == 0) { putname(name); return index; } index++; } putname(name); return -EINVAL; } static int fs_name(unsigned int index, char * buf) { struct file_system_type * tmp; int len; tmp = file_systems; while (tmp && index > 0) { tmp = tmp->next; index--; } if (!tmp) return -EINVAL; len = strlen(tmp->name) + 1; return copy_to_user(buf, tmp->name, len) ? -EFAULT : 0; } static int fs_maxindex(void) { struct file_system_type * tmp; int index; index = 0; for (tmp = file_systems ; tmp ; tmp = tmp->next) index++; return index; } /* * Whee.. Weird sysv syscall. */ asmlinkage int sys_sysfs(int option, ...) { va_list args; int retval = -EINVAL; unsigned int index; lock_kernel(); va_start(args, option); switch (option) { case 1: retval = fs_index(va_arg(args, const char *)); break; case 2: index = va_arg(args, unsigned int); retval = fs_name(index, va_arg(args, char *)); break; case 3: retval = fs_maxindex(); break; } va_end(args); unlock_kernel(); return retval; } static struct proc_fs_info { int flag; char *str; } fs_info[] = { { MS_NOEXEC, ",noexec" }, { MS_NOSUID, ",nosuid" }, { MS_NODEV, ",nodev" }, { MS_SYNCHRONOUS, ",sync" }, { MS_MANDLOCK, ",mand" }, { MS_NOATIME, ",noatime" }, #ifdef MS_NOSUB /* Can't find this except in mount.c */ { MS_NOSUB, ",nosub" }, #endif { 0, NULL } }; static struct proc_nfs_info { int flag; char *str; } nfs_info[] = { { NFS_MOUNT_SOFT, ",soft" }, { NFS_MOUNT_INTR, ",intr" }, { NFS_MOUNT_POSIX, ",posix" }, { NFS_MOUNT_NOCTO, ",nocto" }, { NFS_MOUNT_NOAC, ",noac" }, { 0, NULL } }; int get_filesystem_info( char *buf ) { struct vfsmount *tmp = vfsmntlist; struct proc_fs_info *fs_infop; struct proc_nfs_info *nfs_infop; struct nfs_server *nfss; int len = 0; while ( tmp && len < PAGE_SIZE - 160) { len += sprintf( buf + len, "%s %s %s %s", tmp->mnt_devname, tmp->mnt_dirname, tmp->mnt_sb->s_type->name, tmp->mnt_flags & MS_RDONLY ? "ro" : "rw" ); for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { if (tmp->mnt_flags & fs_infop->flag) { strcpy(buf + len, fs_infop->str); len += strlen(fs_infop->str); } } if (!strcmp("nfs", tmp->mnt_sb->s_type->name)) { nfss = &tmp->mnt_sb->u.nfs_sb.s_server; if (nfss->rsize != NFS_DEF_FILE_IO_BUFFER_SIZE) { len += sprintf(buf+len, ",rsize=%d", nfss->rsize); } if (nfss->wsize != NFS_DEF_FILE_IO_BUFFER_SIZE) { len += sprintf(buf+len, ",wsize=%d", nfss->wsize); } #if 0 if (nfss->timeo != 7*HZ/10) { len += sprintf(buf+len, ",timeo=%d", nfss->timeo*10/HZ); } if (nfss->retrans != 3) { len += sprintf(buf+len, ",retrans=%d", nfss->retrans); } #endif if (nfss->acregmin != 3*HZ) { len += sprintf(buf+len, ",acregmin=%d", nfss->acregmin/HZ); } if (nfss->acregmax != 60*HZ) { len += sprintf(buf+len, ",acregmax=%d", nfss->acregmax/HZ); } if (nfss->acdirmin != 30*HZ) { len += sprintf(buf+len, ",acdirmin=%d", nfss->acdirmin/HZ); } if (nfss->acdirmax != 60*HZ) { len += sprintf(buf+len, ",acdirmax=%d", nfss->acdirmax/HZ); } for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) { if (nfss->flags & nfs_infop->flag) { strcpy(buf + len, nfs_infop->str); len += strlen(nfs_infop->str); } } len += sprintf(buf+len, ",addr=%s", nfss->hostname); } len += sprintf( buf + len, " 0 0\n" ); tmp = tmp->mnt_next; } return len; } int get_filesystem_list(char * buf) { int len = 0; struct file_system_type * tmp; tmp = file_systems; while (tmp && len < PAGE_SIZE - 80) { len += sprintf(buf+len, "%s\t%s\n", tmp->requires_dev ? "" : "nodev", tmp->name); tmp = tmp->next; } return len; } struct file_system_type *get_fs_type(const char *name) { struct file_system_type * fs = file_systems; if (!name) return fs; for (fs = file_systems; fs && strcmp(fs->name, name); fs = fs->next) ; #ifdef CONFIG_KERNELD if (!fs && (request_module(name) == 0)) { for (fs = file_systems; fs && strcmp(fs->name, name); fs = fs->next) ; } #endif return fs; } void __wait_on_super(struct super_block * sb) { struct wait_queue wait = { current, NULL }; add_wait_queue(&sb->s_wait, &wait); repeat: current->state = TASK_UNINTERRUPTIBLE; if (sb->s_lock) { schedule(); goto repeat; } remove_wait_queue(&sb->s_wait, &wait); current->state = TASK_RUNNING; } void sync_supers(kdev_t dev) { struct super_block * sb; for (sb = super_blocks + 0 ; sb < super_blocks + NR_SUPER ; sb++) { if (!sb->s_dev) continue; if (dev && sb->s_dev != dev) continue; wait_on_super(sb); if (!sb->s_dev || !sb->s_dirt) continue; if (dev && (dev != sb->s_dev)) continue; if (sb->s_op && sb->s_op->write_super) sb->s_op->write_super(sb); } } static struct super_block * get_super(kdev_t dev) { struct super_block * s; if (!dev) return NULL; s = 0+super_blocks; while (s < NR_SUPER+super_blocks) if (s->s_dev == dev) { wait_on_super(s); if (s->s_dev == dev) return s; s = 0+super_blocks; } else s++; return NULL; } void put_super(kdev_t dev) { struct super_block * sb; if (dev == ROOT_DEV) { printk("VFS: Root device %s: prepare for armageddon\n", kdevname(dev)); return; } if (!(sb = get_super(dev))) return; if (sb->s_covered) { printk("VFS: Mounted device %s - tssk, tssk\n", kdevname(dev)); return; } if (sb->s_op && sb->s_op->put_super) sb->s_op->put_super(sb); } asmlinkage int sys_ustat(dev_t dev, struct ustat * ubuf) { struct super_block *s; struct ustat tmp; struct statfs sbuf; unsigned long old_fs; int err = -EINVAL; lock_kernel(); s = get_super(to_kdev_t(dev)); if (s == NULL) goto out; err = -ENOSYS; if (!(s->s_op->statfs)) goto out; old_fs = get_fs(); set_fs(get_ds()); s->s_op->statfs(s,&sbuf,sizeof(struct statfs)); set_fs(old_fs); memset(&tmp,0,sizeof(struct ustat)); tmp.f_tfree = sbuf.f_bfree; tmp.f_tinode = sbuf.f_ffree; err = copy_to_user(ubuf,&tmp,sizeof(struct ustat)) ? -EFAULT : 0; out: unlock_kernel(); return err; } static struct super_block * read_super(kdev_t dev,const char *name,int flags, void *data, int silent) { struct super_block * s; struct file_system_type *type; if (!dev) return NULL; check_disk_change(dev); s = get_super(dev); if (s) return s; if (!(type = get_fs_type(name))) { printk("VFS: on device %s: get_fs_type(%s) failed\n", kdevname(dev), name); return NULL; } for (s = 0+super_blocks ;; s++) { if (s >= NR_SUPER+super_blocks) return NULL; if (!(s->s_dev)) break; } s->s_dev = dev; s->s_flags = flags; if (!type->read_super(s,data, silent)) { s->s_dev = 0; return NULL; } s->s_dev = dev; s->s_covered = NULL; s->s_rd_only = 0; s->s_dirt = 0; s->s_type = type; return s; } /* * Unnamed block devices are dummy devices used by virtual * filesystems which don't use real block-devices. -- jrs */ static unsigned int unnamed_dev_in_use[256/(8*sizeof(unsigned int))] = { 0, }; kdev_t get_unnamed_dev(void) { int i; for (i = 1; i < 256; i++) { if (!set_bit(i,unnamed_dev_in_use)) return MKDEV(UNNAMED_MAJOR, i); } return 0; } void put_unnamed_dev(kdev_t dev) { if (!dev || MAJOR(dev) != UNNAMED_MAJOR) return; if (clear_bit(MINOR(dev), unnamed_dev_in_use)) return; printk("VFS: put_unnamed_dev: freeing unused device %s\n", kdevname(dev)); } static int do_umount(kdev_t dev,int unmount_root) { struct super_block * sb; int retval; if (dev==ROOT_DEV && !unmount_root) { /* * Special case for "unmounting" root. We just try to remount * it readonly, and sync() the device. */ if (!(sb=get_super(dev))) return -ENOENT; if (!(sb->s_flags & MS_RDONLY)) { /* * Make sure all quotas are turned off on this device we need to mount * it readonly so no more writes by the quotasystem. * If later on the remount fails too bad there are no quotas running * anymore. Turn them on again by hand. */ quota_off(dev, -1); fsync_dev(dev); retval = do_remount_sb(sb, MS_RDONLY, 0); if (retval) return retval; } return 0; } if (!(sb=get_super(dev)) || !(sb->s_covered)) return -ENOENT; if (!sb->s_covered->i_mount) printk("VFS: umount(%s): mounted inode has i_mount=NULL\n", kdevname(dev)); /* * Before checking if the filesystem is still busy make sure the kernel * doesn't hold any quotafiles open on that device. If the umount fails * too bad there are no quotas running anymore. Turn them on again by hand. */ quota_off(dev, -1); if (!fs_may_umount(dev, sb->s_mounted)) return -EBUSY; sb->s_covered->i_mount = NULL; iput(sb->s_covered); sb->s_covered = NULL; iput(sb->s_mounted); sb->s_mounted = NULL; if (sb->s_op && sb->s_op->write_super && sb->s_dirt) sb->s_op->write_super(sb); put_super(dev); remove_vfsmnt(dev); return 0; } /* * Now umount can handle mount points as well as block devices. * This is important for filesystems which use unnamed block devices. * * There is a little kludge here with the dummy_inode. The current * vfs release functions only use the r_dev field in the inode so * we give them the info they need without using a real inode. * If any other fields are ever needed by any block device release * functions, they should be faked here. -- jrs */ asmlinkage int sys_umount(char * name) { struct inode * inode; kdev_t dev; int retval = -EPERM; struct inode dummy_inode; lock_kernel(); if (!suser()) goto out; retval = namei(name, &inode); if (retval) { retval = lnamei(name, &inode); if (retval) goto out; } if (S_ISBLK(inode->i_mode)) { dev = inode->i_rdev; retval = -EACCES; if (IS_NODEV(inode)) { iput(inode); goto out; } } else { retval = -EINVAL; if (!inode->i_sb || inode != inode->i_sb->s_mounted) { iput(inode); goto out; } dev = inode->i_sb->s_dev; iput(inode); memset(&dummy_inode, 0, sizeof(dummy_inode)); dummy_inode.i_rdev = dev; inode = &dummy_inode; } retval = -ENXIO; if (MAJOR(dev) >= MAX_BLKDEV) { iput(inode); goto out; } retval = do_umount(dev,0); if (!retval) { fsync_dev(dev); if (dev != ROOT_DEV) { blkdev_release (inode); put_unnamed_dev(dev); } } if (inode != &dummy_inode) iput(inode); if (!retval) fsync_dev(dev); out: unlock_kernel(); return retval; } /* * do_mount() does the actual mounting after sys_mount has done the ugly * parameter parsing. When enough time has gone by, and everything uses the * new mount() parameters, sys_mount() can then be cleaned up. * * We cannot mount a filesystem if it has active, used, or dirty inodes. * We also have to flush all inode-data for this device, as the new mount * might need new info. */ int do_mount(kdev_t dev, const char * dev_name, const char * dir_name, const char * type, int flags, void * data) { struct inode * dir_i; struct super_block * sb; struct vfsmount *vfsmnt; int error; if (!(flags & MS_RDONLY) && dev && is_read_only(dev)) return -EACCES; /*flags |= MS_RDONLY;*/ error = namei(dir_name, &dir_i); if (error) return error; if (dir_i->i_count != 1 || dir_i->i_mount) { iput(dir_i); return -EBUSY; } if (!S_ISDIR(dir_i->i_mode)) { iput(dir_i); return -ENOTDIR; } if (!fs_may_mount(dev)) { iput(dir_i); return -EBUSY; } sb = read_super(dev,type,flags,data,0); if (!sb) { iput(dir_i); return -EINVAL; } if (sb->s_covered) { iput(dir_i); return -EBUSY; } vfsmnt = add_vfsmnt(dev, dev_name, dir_name); if (vfsmnt) { vfsmnt->mnt_sb = sb; vfsmnt->mnt_flags = flags; } sb->s_covered = dir_i; dir_i->i_mount = sb->s_mounted; return 0; /* we don't iput(dir_i) - see umount */ } /* * Alters the mount flags of a mounted file system. Only the mount point * is used as a reference - file system type and the device are ignored. * FS-specific mount options can't be altered by remounting. */ static int do_remount_sb(struct super_block *sb, int flags, char *data) { int retval; struct vfsmount *vfsmnt; if (!(flags & MS_RDONLY) && sb->s_dev && is_read_only(sb->s_dev)) return -EACCES; /*flags |= MS_RDONLY;*/ /* If we are remounting RDONLY, make sure there are no rw files open */ if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) if (!fs_may_remount_ro(sb->s_dev)) return -EBUSY; sb->s_flags = (flags & ~MS_RDONLY) | (sb->s_flags & MS_RDONLY); if (sb->s_op && sb->s_op->remount_fs) { retval = sb->s_op->remount_fs(sb, &flags, data); if (retval) return retval; } sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK); vfsmnt = lookup_vfsmnt(sb->s_dev); if (vfsmnt) vfsmnt->mnt_flags = sb->s_flags; return 0; } static int do_remount(const char *dir,int flags,char *data) { struct inode *dir_i; int retval; retval = namei(dir, &dir_i); if (retval) return retval; if (dir_i != dir_i->i_sb->s_mounted) { iput(dir_i); return -EINVAL; } retval = do_remount_sb(dir_i->i_sb, flags, data); iput(dir_i); return retval; } static int copy_mount_options (const void * data, unsigned long *where) { int i; unsigned long page; struct vm_area_struct * vma; *where = 0; if (!data) return 0; vma = find_vma(current->mm, (unsigned long) data); if (!vma || (unsigned long) data < vma->vm_start) return -EFAULT; if (!(vma->vm_flags & VM_READ)) return -EFAULT; i = vma->vm_end - (unsigned long) data; if (PAGE_SIZE <= (unsigned long) i) i = PAGE_SIZE-1; if (!(page = __get_free_page(GFP_KERNEL))) { return -ENOMEM; } if (copy_from_user((void *) page,data,i)) { free_page(page); return -EFAULT; } *where = page; return 0; } /* * Flags is a 16-bit value that allows up to 16 non-fs dependent flags to * be given to the mount() call (ie: read-only, no-dev, no-suid etc). * * data is a (void *) that can point to any structure up to * PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent * information (or be NULL). * * NOTE! As old versions of mount() didn't use this setup, the flags * have to have a special 16-bit magic number in the high word: * 0xC0ED. If this magic word isn't present, the flags and data info * aren't used, as the syscall assumes we are talking to an older * version that didn't understand them. */ asmlinkage int sys_mount(char * dev_name, char * dir_name, char * type, unsigned long new_flags, void * data) { struct file_system_type * fstype; struct inode * inode; struct file_operations * fops; kdev_t dev; int retval = -EPERM; const char * t; unsigned long flags = 0; unsigned long page = 0; lock_kernel(); if (!suser()) goto out; if ((new_flags & (MS_MGC_MSK | MS_REMOUNT)) == (MS_MGC_VAL | MS_REMOUNT)) { retval = copy_mount_options (data, &page); if (retval < 0) goto out; retval = do_remount(dir_name, new_flags & ~MS_MGC_MSK & ~MS_REMOUNT, (char *) page); free_page(page); goto out; } retval = copy_mount_options (type, &page); if (retval < 0) goto out; fstype = get_fs_type((char *) page); free_page(page); retval = -ENODEV; if (!fstype) goto out; t = fstype->name; fops = NULL; if (fstype->requires_dev) { retval = namei(dev_name, &inode); if (retval) goto out; retval = -ENOTBLK; if (!S_ISBLK(inode->i_mode)) { iput(inode); goto out; } retval = -EACCES; if (IS_NODEV(inode)) { iput(inode); goto out; } dev = inode->i_rdev; retval = -ENXIO; if (MAJOR(dev) >= MAX_BLKDEV) { iput(inode); goto out; } fops = get_blkfops(MAJOR(dev)); retval = -ENOTBLK; if (!fops) { iput(inode); goto out; } if (fops->open) { struct file dummy; /* allows read-write or read-only flag */ memset(&dummy, 0, sizeof(dummy)); dummy.f_inode = inode; dummy.f_mode = (new_flags & MS_RDONLY) ? 1 : 3; retval = fops->open(inode, &dummy); if (retval) { iput(inode); goto out; } } } else { retval = -EMFILE; if (!(dev = get_unnamed_dev())) goto out; inode = NULL; } page = 0; if ((new_flags & MS_MGC_MSK) == MS_MGC_VAL) { flags = new_flags & ~MS_MGC_MSK; retval = copy_mount_options(data, &page); if (retval < 0) { put_unnamed_dev(dev); iput(inode); goto out; } } retval = do_mount(dev,dev_name,dir_name,t,flags,(void *) page); free_page(page); if (retval && fops && fops->release) { fops->release(inode, NULL); put_unnamed_dev(dev); } iput(inode); out: unlock_kernel(); return retval; } static void do_mount_root(void) { struct file_system_type * fs_type; struct super_block * sb; struct vfsmount *vfsmnt; struct inode * inode, d_inode; struct file filp; int retval; #ifdef CONFIG_ROOT_NFS if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) if (nfs_root_init(nfs_root_name, nfs_root_addrs) < 0) { printk(KERN_ERR "Root-NFS: Unable to contact NFS " "server for root fs, using /dev/fd0 instead\n"); ROOT_DEV = MKDEV(FLOPPY_MAJOR, 0); } if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) { ROOT_DEV = 0; if ((fs_type = get_fs_type("nfs"))) { sb = &super_blocks[0]; while (sb->s_dev) sb++; sb->s_dev = get_unnamed_dev(); sb->s_flags = root_mountflags & ~MS_RDONLY; if (nfs_root_mount(sb) >= 0) { inode = sb->s_mounted; inode->i_count += 3 ; sb->s_covered = inode; sb->s_rd_only = 0; sb->s_dirt = 0; sb->s_type = fs_type; current->fs->pwd = inode; current->fs->root = inode; ROOT_DEV = sb->s_dev; printk (KERN_NOTICE "VFS: Mounted root (nfs filesystem).\n"); vfsmnt = add_vfsmnt(ROOT_DEV, "/dev/root", "/"); if (!vfsmnt) panic("VFS: add_vfsmnt failed for NFS root.\n"); vfsmnt->mnt_sb = sb; vfsmnt->mnt_flags = sb->s_flags; return; } sb->s_dev = 0; } if (!ROOT_DEV) { printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); ROOT_DEV = MKDEV(FLOPPY_MAJOR, 0); } } #endif #ifdef CONFIG_BLK_DEV_FD if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { floppy_eject(); #ifndef CONFIG_BLK_DEV_RAM printk(KERN_NOTICE "(Warning, this kernel has no ramdisk support)\n"); #endif printk(KERN_NOTICE "VFS: Insert root floppy and press ENTER\n"); wait_for_keypress(); } #endif memset(&filp, 0, sizeof(filp)); memset(&d_inode, 0, sizeof(d_inode)); d_inode.i_rdev = ROOT_DEV; filp.f_inode = &d_inode; if ( root_mountflags & MS_RDONLY) filp.f_mode = 1; /* read only */ else filp.f_mode = 3; /* read write */ retval = blkdev_open(&d_inode, &filp); if (retval == -EROFS) { root_mountflags |= MS_RDONLY; filp.f_mode = 1; retval = blkdev_open(&d_inode, &filp); } if (retval) /* * Allow the user to distinguish between failed open * and bad superblock on root device. */ printk("VFS: Cannot open root device %s\n", kdevname(ROOT_DEV)); else for (fs_type = file_systems ; fs_type ; fs_type = fs_type->next) { if (!fs_type->requires_dev) continue; sb = read_super(ROOT_DEV,fs_type->name,root_mountflags,NULL,1); if (sb) { inode = sb->s_mounted; inode->i_count += 3 ; /* NOTE! it is logically used 4 times, not 1 */ sb->s_covered = inode; sb->s_flags = root_mountflags; current->fs->pwd = inode; current->fs->root = inode; printk ("VFS: Mounted root (%s filesystem)%s.\n", fs_type->name, (sb->s_flags & MS_RDONLY) ? " readonly" : ""); vfsmnt = add_vfsmnt(ROOT_DEV, "/dev/root", "/"); if (!vfsmnt) panic("VFS: add_vfsmnt failed for root fs"); vfsmnt->mnt_sb = sb; vfsmnt->mnt_flags = root_mountflags; return; } } panic("VFS: Unable to mount root fs on %s", kdevname(ROOT_DEV)); } void mount_root(void) { memset(super_blocks, 0, sizeof(super_blocks)); do_mount_root(); } #ifdef CONFIG_BLK_DEV_INITRD int change_root(kdev_t new_root_dev,const char *put_old) { kdev_t old_root_dev; struct vfsmount *vfsmnt; struct inode *old_root,*old_pwd,*inode; unsigned long old_fs; int error; old_root = current->fs->root; old_pwd = current->fs->pwd; old_root_dev = ROOT_DEV; if (!fs_may_mount(new_root_dev)) { printk(KERN_CRIT "New root is busy. Staying in initrd.\n"); return -EBUSY; } ROOT_DEV = new_root_dev; do_mount_root(); old_fs = get_fs(); set_fs(get_ds()); error = namei(put_old,&inode); if (error) inode = NULL; set_fs(old_fs); if (!error && (inode->i_count != 1 || inode->i_mount)) error = -EBUSY; if (!error && !S_ISDIR(inode->i_mode)) error = -ENOTDIR; iput(old_root); /* current->fs->root */ iput(old_pwd); /* current->fs->pwd */ if (error) { int umount_error; if (inode) iput(inode); printk(KERN_NOTICE "Trying to unmount old root ... "); old_root->i_mount = old_root; /* does this belong into do_mount_root ? */ umount_error = do_umount(old_root_dev,1); if (umount_error) printk(KERN_ERR "error %d\n",umount_error); else { printk("okay\n"); invalidate_buffers(old_root_dev); } return umount_error ? error : 0; } iput(old_root); /* sb->s_covered */ remove_vfsmnt(old_root_dev); vfsmnt = add_vfsmnt(old_root_dev,"/dev/root.old",put_old); if (!vfsmnt) printk(KERN_CRIT "Trouble: add_vfsmnt failed\n"); else { vfsmnt->mnt_sb = old_root->i_sb; vfsmnt->mnt_sb->s_covered = inode; vfsmnt->mnt_flags = vfsmnt->mnt_sb->s_flags; } inode->i_mount = old_root; return 0; } #endif