diff -ru /tmp/linux/linux-2.4.0.tar.bz2@/linux/fs/namei.c linux/fs/namei.c --- /tmp/linux/linux-2.4.0.tar.bz2@/linux/fs/namei.c Fri Dec 29 23:07:23 2000 +++ linux/fs/namei.c Wed Jan 10 10:04:21 2001 @@ -99,6 +99,9 @@ * XEmacs seems to be relying on it... */ +/* lookup function for "virtual" files */ +struct dentry *(*lookup_virtual)(struct nameidata *, struct dentry *); + /* In order to reduce some races, while at the same time doing additional * checking and hopefully speeding things up, we copy filenames to the * kernel data space before using them.. @@ -265,9 +268,10 @@ * make sure that nobody added the entry to the dcache in the meantime.. * SMP-safe */ -static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, int flags) +static struct dentry * real_lookup(struct nameidata * nd, struct qstr * name, int flags) { struct dentry * result; + struct dentry *parent = nd->dentry; struct inode *dir = parent->d_inode; down(&dir->i_sem); @@ -286,12 +290,24 @@ lock_kernel(); result = dir->i_op->lookup(dir, dentry); unlock_kernel(); - if (result) + if (result) { dput(dentry); - else + up(&dir->i_sem); + } + else { + up(&dir->i_sem); result = dentry; - } - up(&dir->i_sem); + /* + * If the dentry is negative it might + * refer to a 'virtual' file + */ + if (lookup_virtual && !dentry->d_inode) + lookup_virtual(nd, dentry); + } + } + else + up(&dir->i_sem); + return result; } @@ -494,7 +510,7 @@ /* This does the actual lookups.. */ dentry = cached_lookup(nd->dentry, &this, LOOKUP_CONTINUE); if (!dentry) { - dentry = real_lookup(nd->dentry, &this, LOOKUP_CONTINUE); + dentry = real_lookup(nd, &this, LOOKUP_CONTINUE); err = PTR_ERR(dentry); if (IS_ERR(dentry)) break; @@ -557,7 +573,7 @@ } dentry = cached_lookup(nd->dentry, &this, 0); if (!dentry) { - dentry = real_lookup(nd->dentry, &this, 0); + dentry = real_lookup(nd, &this, 0); err = PTR_ERR(dentry); if (IS_ERR(dentry)) break; diff -ru /tmp/linux/linux-2.4.0.tar.bz2@/linux/fs/super.c linux/fs/super.c --- /tmp/linux/linux-2.4.0.tar.bz2@/linux/fs/super.c Fri Dec 29 23:18:42 2000 +++ linux/fs/super.c Wed Jan 10 10:04:21 2001 @@ -47,7 +47,7 @@ * unmounting a filesystem and re-mounting it (or something * else). */ -static DECLARE_MUTEX(mount_sem); +DECLARE_MUTEX(mount_sem); extern void wait_for_keypress(void); @@ -303,9 +303,10 @@ * support for such beasts we'll have to change prototype. */ -static struct vfsmount *add_vfsmnt(struct nameidata *nd, - struct dentry *root, - const char *dev_name) +struct vfsmount *add_vfsmnt(struct nameidata *nd, + struct dentry *root, + const char *dev_name, + struct mount_operations *mnt_op) { struct vfsmount *mnt; struct super_block *sb = root->d_inode->i_sb; @@ -330,6 +331,7 @@ mnt->mnt_owner = current->uid; atomic_set(&mnt->mnt_count,1); mnt->mnt_sb = sb; + mnt->mnt_op = mnt_op; spin_lock(&dcache_lock); if (nd && !IS_ROOT(nd->dentry) && d_unhashed(nd->dentry)) @@ -417,6 +419,8 @@ list_del(&mnt->mnt_child); spin_unlock(&dcache_lock); /* Now we can work safely */ + if(mnt->mnt_op && mnt->mnt_op->release) + mnt->mnt_op->release(mnt); if (mnt->mnt_parent != mnt) mntput(mnt->mnt_parent); @@ -979,7 +983,7 @@ put_unnamed_dev(dev); return ERR_PTR(-EINVAL); } - mnt = add_vfsmnt(NULL, sb->s_root, NULL); + mnt = add_vfsmnt(NULL, sb->s_root, NULL, NULL); if (!mnt) { kill_super(sb, 0); return ERR_PTR(-ENOMEM); @@ -1010,7 +1014,23 @@ return 0; } -static int do_umount(struct vfsmount *mnt, int umount_root, int flags) +static void try_umount_children(struct vfsmount *mnt) +{ + struct list_head *next, *curr; + struct vfsmount *child; + + /* The mount list is protected by mount_sem */ + curr = mnt->mnt_mounts.next; + while(curr != &mnt->mnt_mounts) { + next = curr->next; + child = list_entry(curr, struct vfsmount, mnt_child); + if(child->mnt_op && child->mnt_op->umount) + child->mnt_op->umount(child); + curr = next; + } +} + +int do_umount(struct vfsmount *mnt, int umount_root, int flags) { struct super_block * sb = mnt->mnt_sb; @@ -1036,6 +1056,9 @@ return retval; } + /* umount any automatic mounts */ + try_umount_children(mnt); + spin_lock(&dcache_lock); if (mnt->mnt_instances.next != mnt->mnt_instances.prev) { @@ -1213,7 +1236,7 @@ down(&new_nd.dentry->d_inode->i_zombie); if (IS_DEADDIR(new_nd.dentry->d_inode)) err = -ENOENT; - else if (add_vfsmnt(&new_nd, old_nd.dentry, old_nd.mnt->mnt_devname)) + else if (add_vfsmnt(&new_nd, old_nd.dentry, old_nd.mnt->mnt_devname, NULL)) err = 0; up(&new_nd.dentry->d_inode->i_zombie); up(&mount_sem); @@ -1398,7 +1421,7 @@ down(&nd.dentry->d_inode->i_zombie); if (!IS_DEADDIR(nd.dentry->d_inode)) { retval = -ENOMEM; - mnt = add_vfsmnt(&nd, sb->s_root, dev_name); + mnt = add_vfsmnt(&nd, sb->s_root, dev_name, NULL); } up(&nd.dentry->d_inode->i_zombie); if (!mnt) @@ -1603,10 +1626,10 @@ devfs_mk_symlink (NULL, "root", DEVFS_FL_DEFAULT, path + 5 + path_start, NULL, NULL); memcpy (path + path_start, "/dev/", 5); - vfsmnt = add_vfsmnt(NULL, sb->s_root, path + path_start); + vfsmnt = add_vfsmnt(NULL, sb->s_root, path + path_start, NULL); } else - vfsmnt = add_vfsmnt(NULL, sb->s_root, "/dev/root"); + vfsmnt = add_vfsmnt(NULL, sb->s_root, "/dev/root", NULL); /* FIXME: if something will try to umount us right now... */ if (vfsmnt) { set_fs_root(current->fs, vfsmnt, sb->s_root); diff -ru /tmp/linux/linux-2.4.0.tar.bz2@/linux/include/linux/fs.h linux/include/linux/fs.h --- /tmp/linux/linux-2.4.0.tar.bz2@/linux/include/linux/fs.h Thu Jan 4 23:50:47 2001 +++ linux/include/linux/fs.h Wed Jan 10 10:04:21 2001 @@ -874,6 +874,10 @@ extern void kern_umount(struct vfsmount *); extern int may_umount(struct vfsmount *); extern long do_mount(char *, char *, char *, unsigned long, void *); +extern struct vfsmount *add_vfsmnt(struct nameidata *nd, struct dentry *root, + const char *dev_name, + struct mount_operations *mnt_op); +extern int do_umount(struct vfsmount *mnt, int umount_root, int flags); extern int vfs_statfs(struct super_block *, struct statfs *); @@ -1163,6 +1167,9 @@ /* needed for stackable file system support */ extern loff_t default_llseek(struct file *file, loff_t offset, int origin); + +/* lookup function for "virtual" files */ +extern struct dentry *(*lookup_virtual)(struct nameidata *, struct dentry *); extern int __user_walk(const char *, unsigned, struct nameidata *); extern int path_init(const char *, unsigned, struct nameidata *); diff -ru /tmp/linux/linux-2.4.0.tar.bz2@/linux/include/linux/mount.h linux/include/linux/mount.h --- /tmp/linux/linux-2.4.0.tar.bz2@/linux/include/linux/mount.h Sun Sep 17 18:51:57 2000 +++ linux/include/linux/mount.h Wed Jan 10 10:04:21 2001 @@ -14,6 +14,8 @@ #define MNT_VISIBLE 1 +extern struct semaphore mount_sem; + struct vfsmount { struct dentry *mnt_mountpoint; /* dentry of mountpoint */ @@ -30,6 +32,20 @@ char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ struct list_head mnt_list; uid_t mnt_owner; + struct mount_operations *mnt_op; /* Operations on vfsmount */ +}; + +/* + * Mount operations: + * release(node) - called when this node has been umounted + * umount(node) - called when the parent is being umounted + * + * mount_sem is held in all + */ + +struct mount_operations { + void (*release) (struct vfsmount *); + void (*umount) (struct vfsmount *); }; static inline struct vfsmount *mntget(struct vfsmount *mnt) diff -ru /tmp/linux/linux-2.4.0.tar.bz2@/linux/kernel/ksyms.c linux/kernel/ksyms.c --- /tmp/linux/linux-2.4.0.tar.bz2@/linux/kernel/ksyms.c Wed Jan 3 01:45:37 2001 +++ linux/kernel/ksyms.c Wed Jan 10 10:04:21 2001 @@ -261,6 +261,9 @@ EXPORT_SYMBOL(filemap_sync); EXPORT_SYMBOL(lock_page); +/* lookup function for "virtual" files */ +EXPORT_SYMBOL(lookup_virtual); + /* device registration */ EXPORT_SYMBOL(register_chrdev); EXPORT_SYMBOL(unregister_chrdev); @@ -313,6 +316,9 @@ EXPORT_SYMBOL(kern_mount); EXPORT_SYMBOL(kern_umount); EXPORT_SYMBOL(may_umount); +EXPORT_SYMBOL(add_vfsmnt); +EXPORT_SYMBOL(do_umount); +EXPORT_SYMBOL(mount_sem); /* executable format registration */ EXPORT_SYMBOL(register_binfmt);