litmus-rt.git - The LITMUS^RT kernel.

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author	Mark Brown <broonie@kernel.org>	2015-02-09 02:09:48 -0500
committer	Mark Brown <broonie@kernel.org>	2015-02-09 02:09:48 -0500
commit	b34510b70d2a703fcc7fc018380af73e5f448f7f (patch)
tree	21aa60960fcfde9aaa7a89fec0afd72303944a80 /include/uapi/linux/const.h
parent	e36f014edff70fc02b3d3d79cead1d58f289332e (diff)
parent	1b9f1ae8907cb13d3d2538d98385b2744c9490d5 (diff)

Merge tag 'asoc-v3.19-rc2' into asoc-linus

ASoC: Updates for v3.20 Nothing too exciting here yet, a small optimization for DAPM from Lars-Peter and a few small bits and pieces for drivers but nothing that really stands out. # gpg: Signature made Tue 30 Dec 2014 00:15:48 HKT using RSA key ID 5D5487D0 # gpg: Oops: keyid_from_fingerprint: no pubkey # gpg: key AF88CD16: no public key for trusted key - skipped # gpg: key AF88CD16 marked as ultimately trusted # gpg: key 5621E907: no public key for trusted key - skipped # gpg: key 5621E907 marked as ultimately trusted # gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>" # gpg: aka "Mark Brown <broonie@debian.org>" # gpg: aka "Mark Brown <broonie@kernel.org>" # gpg: aka "Mark Brown <broonie@tardis.ed.ac.uk>" # gpg: aka "Mark Brown <broonie@linaro.org>" # gpg: aka "Mark Brown <Mark.Brown@linaro.org>"

Diffstat (limited to 'include/uapi/linux/const.h')

0 files changed, 0 insertions, 0 deletions

/* * linux/fs/pnode.c * * (C) Copyright IBM Corporation 2005. * Released under GPL v2. * Author : Ram Pai (linuxram@us.ibm.com) * */ #include <linux/mnt_namespace.h> #include <linux/mount.h> #include <linux/fs.h> #include <linux/nsproxy.h> #include "internal.h" #include "pnode.h" /* return the next shared peer mount of @p */ static inline struct mount *next_peer(struct mount *p) { return list_entry(p->mnt_share.next, struct mount, mnt_share); } static inline struct mount *first_slave(struct mount *p) { return list_entry(p->mnt_slave_list.next, struct mount, mnt_slave); } static inline struct mount *last_slave(struct mount *p) { return list_entry(p->mnt_slave_list.prev, struct mount, mnt_slave); } static inline struct mount *next_slave(struct mount *p) { return list_entry(p->mnt_slave.next, struct mount, mnt_slave); } static struct mount *get_peer_under_root(struct mount *mnt, struct mnt_namespace *ns, const struct path *root) { struct mount *m = mnt; do { /* Check the namespace first for optimization */ if (m->mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root)) return m; m = next_peer(m); } while (m != mnt); return NULL; } /* * Get ID of closest dominating peer group having a representative * under the given root. * * Caller must hold namespace_sem */ int get_dominating_id(struct mount *mnt, const struct path *root) { struct mount *m; for (m = mnt->mnt_master; m != NULL; m = m->mnt_master) { struct mount *d = get_peer_under_root(m, mnt->mnt_ns, root); if (d) return d->mnt_group_id; } return 0; } static int do_make_slave(struct mount *mnt) { struct mount *master, *slave_mnt; if (list_empty(&mnt->mnt_share)) { if (IS_MNT_SHARED(mnt)) { mnt_release_group_id(mnt); CLEAR_MNT_SHARED(mnt); } master = mnt->mnt_master; if (!master) { struct list_head *p = &mnt->mnt_slave_list; while (!list_empty(p)) { slave_mnt = list_first_entry(p, struct mount, mnt_slave); list_del_init(&slave_mnt->mnt_slave); slave_mnt->mnt_master = NULL; } return 0; } } else { struct mount *m; /* * slave 'mnt' to a peer mount that has the * same root dentry. If none is available then * slave it to anything that is available. */ for (m = master = next_peer(mnt); m != mnt; m = next_peer(m)) { if (m->mnt.mnt_root == mnt->mnt.mnt_root) { master = m; break; } } list_del_init(&mnt->mnt_share); mnt->mnt_group_id = 0; CLEAR_MNT_SHARED(mnt); } list_for_each_entry(slave_mnt, &mnt->mnt_slave_list, mnt_slave) slave_mnt->mnt_master = master; list_move(&mnt->mnt_slave, &master->mnt_slave_list); list_splice(&mnt->mnt_slave_list, master->mnt_slave_list.prev); INIT_LIST_HEAD(&mnt->mnt_slave_list); mnt->mnt_master = master; return 0; } /* * vfsmount lock must be held for write */ void change_mnt_propagation(struct mount *mnt, int type) { if (type == MS_SHARED) { set_mnt_shared(mnt); return; } do_make_slave(mnt); if (type != MS_SLAVE) { list_del_init(&mnt->mnt_slave); mnt->mnt_master = NULL; if (type == MS_UNBINDABLE) mnt->mnt.mnt_flags |= MNT_UNBINDABLE; else mnt->mnt.mnt_flags &= ~MNT_UNBINDABLE; } } /* * get the next mount in the propagation tree. * @m: the mount seen last * @origin: the original mount from where the tree walk initiated * * Note that peer groups form contiguous segments of slave lists. * We rely on that in get_source() to be able to find out if * vfsmount found while iterating with propagation_next() is * a peer of one we'd found earlier. */ static struct mount *propagation_next(struct mount *m, struct mount *origin) { /* are there any slaves of this mount? */ if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) return first_slave(m); while (1) { struct mount *master = m->mnt_master; if (master == origin->mnt_master) { struct mount *next = next_peer(m); return (next == origin) ? NULL : next; } else if (m->mnt_slave.next != &master->mnt_slave_list) return next_slave(m); /* back at master */ m = master; } } static struct mount *skip_propagation_subtree(struct mount *m, struct mount *origin) { /* * Advance m such that propagation_next will not return * the slaves of m. */ if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) m = last_slave(m); return m; } static struct mount *next_group(struct mount *m, struct mount *origin) { while (1) { while (1) { struct mount *next; if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list)) return first_slave(m); next = next_peer(m); if (m->mnt_group_id == origin->mnt_group_id) { if (next == origin) return NULL; } else if (m->mnt_slave.next != &next->mnt_slave) break; m = next; } /* m is the last peer */ while (1) { struct mount *master = m->mnt_master; if (m->mnt_slave.next != &master->mnt_slave_list) return next_slave(m); m = next_peer(master); if (master->mnt_group_id == origin->mnt_group_id) break; if (master->mnt_slave.next == &m->mnt_slave) break; m = master; } if (m == origin) return NULL; } } /* all accesses are serialized by namespace_sem */ static struct user_namespace *user_ns; static struct mount *last_dest, *first_source, *last_source, *dest_master; static struct mountpoint *mp; static struct hlist_head *list; static inline bool peers(struct mount *m1, struct mount *m2) { return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id; } static int propagate_one(struct mount *m) { struct mount *child; int type; /* skip ones added by this propagate_mnt() */ if (IS_MNT_NEW(m)) return 0; /* skip if mountpoint isn't covered by it */ if (!is_subdir(mp->m_dentry, m->mnt.mnt_root)) return 0; if (peers(m, last_dest)) { type = CL_MAKE_SHARED; } else { struct mount *n, *p; bool done; for (n = m; ; n = p) { p = n->mnt_master; if (p == dest_master || IS_MNT_MARKED(p)) break; } do { struct mount *parent = last_source->mnt_parent; if (last_source == first_source) break; done = parent->mnt_master == p; if (done && peers(n, parent)) break; last_source = last_source->mnt_master; } while (!done); type = CL_SLAVE; /* beginning of peer group among the slaves? */ if (IS_MNT_SHARED(m)) type |= CL_MAKE_SHARED; } /* Notice when we are propagating across user namespaces */ if (m->mnt_ns->user_ns != user_ns) type |= CL_UNPRIVILEGED; child = copy_tree(last_source, last_source->mnt.mnt_root, type); if (IS_ERR(child)) return PTR_ERR(child); child->mnt.mnt_flags &= ~MNT_LOCKED; mnt_set_mountpoint(m, mp, child); last_dest = m; last_source = child; if (m->mnt_master != dest_master) { read_seqlock_excl(&mount_lock); SET_MNT_MARK(m->mnt_master); read_sequnlock_excl(&mount_lock); } hlist_add_head(&child->mnt_hash, list); return count_mounts(m->mnt_ns, child); } /* * mount 'source_mnt' under the destination 'dest_mnt' at * dentry 'dest_dentry'. And propagate that mount to * all the peer and slave mounts of 'dest_mnt'. * Link all the new mounts into a propagation tree headed at * source_mnt. Also link all the new mounts using ->mnt_list * headed at source_mnt's ->mnt_list * * @dest_mnt: destination mount. * @dest_dentry: destination dentry. * @source_mnt: source mount. * @tree_list : list of heads of trees to be attached. */ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, struct mount *source_mnt, struct hlist_head *tree_list) { struct mount *m, *n; int ret = 0; /* * we don't want to bother passing tons of arguments to * propagate_one(); everything is serialized by namespace_sem, * so globals will do just fine. */ user_ns = current->nsproxy->mnt_ns->user_ns; last_dest = dest_mnt; first_source = source_mnt; last_source = source_mnt; mp = dest_mp; list = tree_list; dest_master = dest_mnt->mnt_master; /* all peers of dest_mnt, except dest_mnt itself */ for (n = next_peer(dest_mnt); n != dest_mnt; n = next_peer(n)) { ret = propagate_one(n); if (ret) goto out; } /* all slave groups */ for (m = next_group(dest_mnt, dest_mnt); m; m = next_group(m, dest_mnt)) { /* everything in that slave group */ n = m; do { ret = propagate_one(n); if (ret) goto out; n = next_peer(n); } while (n != m); } out: read_seqlock_excl(&mount_lock); hlist_for_each_entry(n, tree_list, mnt_hash) { m = n->mnt_parent; if (m->mnt_master != dest_mnt->mnt_master) CLEAR_MNT_MARK(m->mnt_master); } read_sequnlock_excl(&mount_lock); return ret; } static struct mount *find_topper(struct mount *mnt) { /* If there is exactly one mount covering mnt completely return it. */ struct mount *child; if (!list_is_singular(&mnt->mnt_mounts)) return NULL; child = list_first_entry(&mnt->mnt_mounts, struct mount, mnt_child); if (child->mnt_mountpoint != mnt->mnt.mnt_root) return NULL; return child; } /* * return true if the refcount is greater than count */ static inline int do_refcount_check(struct mount *mnt, int count) { return mnt_get_count(mnt) > count; } /* * check if the mount 'mnt' can be unmounted successfully. * @mnt: the mount to be checked for unmount * NOTE: unmounting 'mnt' would naturally propagate to all * other mounts its parent propagates to. * Check if any of these mounts that **do not have submounts** * have more references than 'refcnt'. If so return busy. * * vfsmount lock must be held for write */ int propagate_mount_busy(struct mount *mnt, int refcnt) { struct mount *m, *child, *topper; struct mount *parent = mnt->mnt_parent; if (mnt == parent) return do_refcount_check(mnt, refcnt); /* * quickly check if the current mount can be unmounted. * If not, we don't have to go checking for all other * mounts */ if (!list_empty(&mnt->mnt_mounts) || do_refcount_check(mnt, refcnt)) return 1; for (m = propagation_next(parent, parent); m; m = propagation_next(m, parent)) { int count = 1; child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint); if (!child) continue; /* Is there exactly one mount on the child that covers * it completely whose reference should be ignored? */ topper = find_topper(child); if (topper) count += 1; else if (!list_empty(&child->mnt_mounts)) continue; if (do_refcount_check(child, count)) return 1; } return 0; } /* * Clear MNT_LOCKED when it can be shown to be safe. * * mount_lock lock must be held for write */ void propagate_mount_unlock(struct mount *mnt) { struct mount *parent = mnt->mnt_parent; struct mount *m, *child; BUG_ON(parent == mnt); for (m = propagation_next(parent, parent); m; m = propagation_next(m, parent)) { child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint); if (child) child->mnt.mnt_flags &= ~MNT_LOCKED; } } static void umount_one(struct mount *mnt, struct list_head *to_umount) { CLEAR_MNT_MARK(mnt); mnt->mnt.mnt_flags |= MNT_UMOUNT; list_del_init(&mnt->mnt_child); list_del_init(&mnt->mnt_umounting); list_move_tail(&mnt->mnt_list, to_umount); } /* * NOTE: unmounting 'mnt' naturally propagates to all other mounts its * parent propagates to. */ static bool __propagate_umount(struct mount *mnt, struct list_head *to_umount, struct list_head *to_restore) { bool progress = false; struct mount *child; /* * The state of the parent won't change if this mount is * already unmounted or marked as without children. */ if (mnt->mnt.mnt_flags & (MNT_UMOUNT | MNT_MARKED)) goto out; /* Verify topper is the only grandchild that has not been * speculatively unmounted. */ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { if (child->mnt_mountpoint == mnt->mnt.mnt_root) continue; if (!list_empty(&child->mnt_umounting) && IS_MNT_MARKED(child)) continue; /* Found a mounted child */ goto children; } /* Mark mounts that can be unmounted if not locked */ SET_MNT_MARK(mnt); progress = true; /* If a mount is without children and not locked umount it. */ if (!IS_MNT_LOCKED(mnt)) { umount_one(mnt, to_umount); } else { children: list_move_tail(&mnt->mnt_umounting, to_restore); } out: return progress; } static void umount_list(struct list_head *to_umount, struct list_head *to_restore) { struct mount *mnt, *child, *tmp; list_for_each_entry(mnt, to_umount, mnt_list) { list_for_each_entry_safe(child, tmp, &mnt->mnt_mounts, mnt_child) { /* topper? */ if (child->mnt_mountpoint == mnt->mnt.mnt_root) list_move_tail(&child->mnt_umounting, to_restore); else umount_one(child, to_umount); } } } static void restore_mounts(struct list_head *to_restore) { /* Restore mounts to a clean working state */ while (!list_empty(to_restore)) { struct mount *mnt, *parent; struct mountpoint *mp; mnt = list_first_entry(to_restore, struct mount, mnt_umounting); CLEAR_MNT_MARK(mnt); list_del_init(&mnt->mnt_umounting); /* Should this mount be reparented? */ mp = mnt->mnt_mp; parent = mnt->mnt_parent; while (parent->mnt.mnt_flags & MNT_UMOUNT) { mp = parent->mnt_mp; parent = parent->mnt_parent; } if (parent != mnt->mnt_parent) mnt_change_mountpoint(parent, mp, mnt); } } static void cleanup_umount_visitations(struct list_head *visited) { while (!list_empty(visited)) { struct mount *mnt = list_first_entry(visited, struct mount, mnt_umounting); list_del_init(&mnt->mnt_umounting); } } /* * collect all mounts that receive propagation from the mount in @list, * and return these additional mounts in the same list. * @list: the list of mounts to be unmounted. * * vfsmount lock must be held for write */ int propagate_umount(struct list_head *list) { struct mount *mnt; LIST_HEAD(to_restore); LIST_HEAD(to_umount); LIST_HEAD(visited); /* Find candidates for unmounting */ list_for_each_entry_reverse(mnt, list, mnt_list) { struct mount *parent = mnt->mnt_parent; struct mount *m; /* * If this mount has already been visited it is known that it's * entire peer group and all of their slaves in the propagation * tree for the mountpoint has already been visited and there is * no need to visit them again. */ if (!list_empty(&mnt->mnt_umounting)) continue; list_add_tail(&mnt->mnt_umounting, &visited); for (m = propagation_next(parent, parent); m; m = propagation_next(m, parent)) { struct mount *child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint); if (!child) continue; if (!list_empty(&child->mnt_umounting)) { /* * If the child has already been visited it is * know that it's entire peer group and all of * their slaves in the propgation tree for the * mountpoint has already been visited and there * is no need to visit this subtree again. */ m = skip_propagation_subtree(m, parent); continue; } else if (child->mnt.mnt_flags & MNT_UMOUNT) { /* * We have come accross an partially unmounted * mount in list that has not been visited yet. * Remember it has been visited and continue * about our merry way. */ list_add_tail(&child->mnt_umounting, &visited); continue; } /* Check the child and parents while progress is made */ while (__propagate_umount(child, &to_umount, &to_restore)) { /* Is the parent a umount candidate? */ child = child->mnt_parent; if (list_empty(&child->mnt_umounting)) break; } } } umount_list(&to_umount, &to_restore); restore_mounts(&to_restore); cleanup_umount_visitations(&visited); list_splice_tail(&to_umount, list); return 0; }


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