adds support for mount/umount propogation for autofs initiated operations, RP
fs/namespace.c | 151 +++++++++++++++++--------------------------------- fs/pnode.c | 13 ++-- include/linux/pnode.h | 3 3 files changed, 61 insertions(+), 106 deletions(-) Index: 2.6.12.work1/fs/namespace.c =================================================================== --- 2.6.12.work1.orig/fs/namespace.c +++ 2.6.12.work1/fs/namespace.c @@ -215,6 +215,9 @@ struct vfsmount *do_attach_prepare_mnt(s if(!(child_mnt = clone_mnt(template_mnt, template_mnt->mnt_root))) return NULL; + spin_lock(&vfsmount_lock); + list_del_init(&child_mnt->mnt_fslink); + spin_unlock(&vfsmount_lock); } else child_mnt = template_mnt; @@ -352,38 +355,16 @@ struct seq_operations mounts_op = { * open files, pwds, chroots or sub mounts that are * busy. */ -//TOBEFIXED int may_umount_tree(struct vfsmount *mnt) { - struct list_head *next; - struct vfsmount *this_parent = mnt; - int actual_refs; - int minimum_refs; + int actual_refs=0; + int minimum_refs=0; + struct vfsmount *p; spin_lock(&vfsmount_lock); - actual_refs = atomic_read(&mnt->mnt_count); - minimum_refs = 2; -repeat: - next = this_parent->mnt_mounts.next; -resume: - while (next != &this_parent->mnt_mounts) { - struct vfsmount *p = list_entry(next, struct vfsmount, mnt_child); - - next = next->next; - + for (p = mnt; p; p = next_mnt(p, mnt)) { actual_refs += atomic_read(&p->mnt_count); minimum_refs += 2; - - if (!list_empty(&p->mnt_mounts)) { - this_parent = p; - goto repeat; - } - } - - if (this_parent != mnt) { - next = this_parent->mnt_child.next; - this_parent = this_parent->mnt_parent; - goto resume; } spin_unlock(&vfsmount_lock); @@ -395,18 +376,18 @@ resume: EXPORT_SYMBOL(may_umount_tree); -int mount_busy(struct vfsmount *mnt) +int mount_busy(struct vfsmount *mnt, int refcnt) { struct vfspnode *parent_pnode; if (mnt == mnt->mnt_parent || !IS_MNT_SHARED(mnt->mnt_parent)) - return do_refcount_check(mnt, 2); + return do_refcount_check(mnt, refcnt); parent_pnode = mnt->mnt_parent->mnt_pnode; BUG_ON(!parent_pnode); return pnode_mount_busy(parent_pnode, mnt->mnt_mountpoint, - mnt->mnt_root, mnt); + mnt->mnt_root, mnt, refcnt); } /** @@ -424,7 +405,7 @@ int mount_busy(struct vfsmount *mnt) */ int may_umount(struct vfsmount *mnt) { - if (mount_busy(mnt)) + if (mount_busy(mnt, 2)) return -EBUSY; return 0; } @@ -445,6 +426,25 @@ void do_detach_mount(struct vfsmount *mn spin_lock(&vfsmount_lock); } +void umount_mnt(struct vfsmount *mnt) +{ + if (mnt->mnt_parent != mnt && + IS_MNT_SHARED(mnt->mnt_parent)) { + struct vfspnode *parent_pnode + = mnt->mnt_parent->mnt_pnode; + BUG_ON(!parent_pnode); + pnode_umount(parent_pnode, + mnt->mnt_mountpoint, + mnt->mnt_root); + } else { + if (IS_MNT_SHARED(mnt) || IS_MNT_SLAVE(mnt)) { + BUG_ON(!mnt->mnt_pnode); + pnode_disassociate_mnt(mnt); + } + do_detach_mount(mnt); + } +} + void umount_tree(struct vfsmount *mnt) { struct vfsmount *p; @@ -459,21 +459,7 @@ void umount_tree(struct vfsmount *mnt) mnt = list_entry(kill.next, struct vfsmount, mnt_list); list_del_init(&mnt->mnt_list); list_del_init(&mnt->mnt_fslink); - if (mnt->mnt_parent != mnt && - IS_MNT_SHARED(mnt->mnt_parent)) { - struct vfspnode *parent_pnode - = mnt->mnt_parent->mnt_pnode; - BUG_ON(!parent_pnode); - pnode_umount(parent_pnode, - mnt->mnt_mountpoint, - mnt->mnt_root); - } else { - if (IS_MNT_SHARED(mnt) || IS_MNT_SLAVE(mnt)) { - BUG_ON(!mnt->mnt_pnode); - pnode_disassociate_mnt(mnt); - } - do_detach_mount(mnt); - } + umount_mnt(mnt); } } @@ -568,7 +554,7 @@ int do_umount(struct vfsmount *mnt, int spin_lock(&vfsmount_lock); } retval = -EBUSY; - if (flags & MNT_DETACH || !mount_busy(mnt)) { + if (flags & MNT_DETACH || !mount_busy(mnt, 2)) { if (!list_empty(&mnt->mnt_list)) umount_tree(mnt); retval = 0; @@ -1490,6 +1476,8 @@ void mark_mounts_for_expiry(struct list_ if (list_empty(mounts)) return; + down_write(&namespace_sem); + spin_lock(&vfsmount_lock); /* extract from the expiration list every vfsmount that matches the @@ -1499,8 +1487,7 @@ void mark_mounts_for_expiry(struct list_ * cleared by mntput()) */ list_for_each_entry_safe(mnt, next, mounts, mnt_fslink) { - if (!xchg(&mnt->mnt_expiry_mark, 1) || - atomic_read(&mnt->mnt_count) != 1) + if (!xchg(&mnt->mnt_expiry_mark, 1) || mount_busy(mnt, 1)) continue; mntget(mnt); @@ -1508,12 +1495,13 @@ void mark_mounts_for_expiry(struct list_ } /* - * go through the vfsmounts we've just consigned to the graveyard to - * - check that they're still dead + * go through the vfsmounts we've just consigned to the graveyard * - delete the vfsmount from the appropriate namespace under lock * - dispose of the corpse */ while (!list_empty(&graveyard)) { + struct super_block *sb; + mnt = list_entry(graveyard.next, struct vfsmount, mnt_fslink); list_del_init(&mnt->mnt_fslink); @@ -1524,60 +1512,25 @@ void mark_mounts_for_expiry(struct list_ continue; get_namespace(namespace); - spin_unlock(&vfsmount_lock); - down_write(&namespace_sem); - spin_lock(&vfsmount_lock); - - /* check that it is still dead: the count should now be 2 - as - * contributed by the vfsmount parent and the mntget above */ - if (atomic_read(&mnt->mnt_count) == 2) { - struct vfsmount *xdmnt; - struct dentry *xdentry; - - /* delete from the namespace */ - list_del_init(&mnt->mnt_list); - list_del_init(&mnt->mnt_child); - list_del_init(&mnt->mnt_hash); - mnt->mnt_mountpoint->d_mounted--; - - xdentry = mnt->mnt_mountpoint; - mnt->mnt_mountpoint = mnt->mnt_root; - xdmnt = mnt->mnt_parent; - mnt->mnt_parent = mnt; - - spin_unlock(&vfsmount_lock); - - mntput(xdmnt); - dput(xdentry); - - /* now lay it to rest if this was the last ref on the - * superblock */ - if (atomic_read(&mnt->mnt_sb->s_active) == 1) { - /* last instance - try to be smart */ - lock_kernel(); - DQUOT_OFF(mnt->mnt_sb); - acct_auto_close(mnt->mnt_sb); - unlock_kernel(); - } - - mntput(mnt); - } else { - /* someone brought it back to life whilst we didn't - * have any locks held so return it to the expiration - * list */ - list_add_tail(&mnt->mnt_fslink, mounts); - spin_unlock(&vfsmount_lock); + sb = mnt->mnt_sb; + umount_mnt(mnt); + /* + * now lay it to rest if this was the last ref on the + * superblock + */ + if (atomic_read(&sb->s_active) == 1) { + /* last instance - try to be smart */ + lock_kernel(); + DQUOT_OFF(sb); + acct_auto_close(sb); + unlock_kernel(); } - - up_write(&namespace_sem); - mntput(mnt); - put_namespace(namespace); - spin_lock(&vfsmount_lock); + put_namespace(namespace); } - spin_unlock(&vfsmount_lock); + up_write(&namespace_sem); } EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); Index: 2.6.12.work1/fs/pnode.c =================================================================== --- 2.6.12.work1.orig/fs/pnode.c +++ 2.6.12.work1/fs/pnode.c @@ -34,7 +34,7 @@ enum pnode_vfs_type { static kmem_cache_t * pnode_cachep; /* spinlock for pnode related operations */ - __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfspnode_lock); + __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfspnode_lock); void __init pnode_init(unsigned long mempages) @@ -274,7 +274,8 @@ int pnode_merge_pnode(struct vfspnode *p } static int vfs_busy(struct vfsmount *mnt, struct dentry *dentry, - struct dentry *rootdentry, struct vfsmount *origmnt) + struct dentry *rootdentry, struct vfsmount *origmnt, + int refcnt) { struct vfsmount *child_mnt; int ret=0; @@ -288,16 +289,16 @@ static int vfs_busy(struct vfsmount *mnt if (list_empty(&child_mnt->mnt_mounts)) { if (origmnt == child_mnt) - ret = do_refcount_check(child_mnt, 3); - else - ret = do_refcount_check(child_mnt, 2); + ret = do_refcount_check(child_mnt, refcnt+1); + else + ret = do_refcount_check(child_mnt, refcnt); } mntput(child_mnt); return ret; } int pnode_mount_busy(struct vfspnode *pnode, struct dentry *mntpt, - struct dentry *root, struct vfsmount *mnt) + struct dentry *root, struct vfsmount *mnt, int refcnt) { int ret=0; struct vfsmount *slave_mnt, *member_mnt, *t_m; Index: 2.6.12.work1/include/linux/pnode.h =================================================================== --- 2.6.12.work1.orig/include/linux/pnode.h +++ 2.6.12.work1/include/linux/pnode.h @@ -86,5 +86,6 @@ int pnode_prepare_mount(struct vfspnode struct vfsmount *, struct vfsmount *); int pnode_real_mount(struct vfspnode *, int); int pnode_umount(struct vfspnode *, struct dentry *, struct dentry *); -int pnode_mount_busy(struct vfspnode *, struct dentry *, struct dentry *, struct vfsmount *); +int pnode_mount_busy(struct vfspnode *, struct dentry *, struct dentry *, + struct vfsmount *, int); 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