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authorLinus Torvalds <torvalds@linux-foundation.org>2014-03-30 17:26:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-30 17:26:08 -0700
commitfedc1ed0f11be666de066b0c78443254736a942e (patch)
treed1911f00911c9fc5d22f90fb8492ee87ff9506e4 /fs/pnode.c
parent01358e562a8b97f50ec04025c009c71508e6d373 (diff)
parent38129a13e6e71f666e0468e99fdd932a687b4d7e (diff)
downloadlinux-linaro-stable-fedc1ed0f11be666de066b0c78443254736a942e.tar.gz
Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "Switch mnt_hash to hlist, turning the races between __lookup_mnt() and hash modifications into false negatives from __lookup_mnt() (instead of hangs)" On the false negatives from __lookup_mnt(): "The *only* thing we care about is not getting stuck in __lookup_mnt(). If it misses an entry because something in front of it just got moved around, etc, we are fine. We'll notice that mount_lock mismatch and that'll be it" * 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch mnt_hash to hlist don't bother with propagate_mnt() unless the target is shared keep shadowed vfsmounts together resizable namespace.c hashes
Diffstat (limited to 'fs/pnode.c')
-rw-r--r--fs/pnode.c26
1 files changed, 15 insertions, 11 deletions
diff --git a/fs/pnode.c b/fs/pnode.c
index c7221bb19801..88396df725b4 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -220,14 +220,14 @@ static struct mount *get_source(struct mount *dest,
* @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 list_head *tree_list)
+ struct mount *source_mnt, struct hlist_head *tree_list)
{
struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
struct mount *m, *child;
int ret = 0;
struct mount *prev_dest_mnt = dest_mnt;
struct mount *prev_src_mnt = source_mnt;
- LIST_HEAD(tmp_list);
+ HLIST_HEAD(tmp_list);
for (m = propagation_next(dest_mnt, dest_mnt); m;
m = propagation_next(m, dest_mnt)) {
@@ -246,27 +246,29 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp,
child = copy_tree(source, source->mnt.mnt_root, type);
if (IS_ERR(child)) {
ret = PTR_ERR(child);
- list_splice(tree_list, tmp_list.prev);
+ tmp_list = *tree_list;
+ tmp_list.first->pprev = &tmp_list.first;
+ INIT_HLIST_HEAD(tree_list);
goto out;
}
if (is_subdir(dest_mp->m_dentry, m->mnt.mnt_root)) {
mnt_set_mountpoint(m, dest_mp, child);
- list_add_tail(&child->mnt_hash, tree_list);
+ hlist_add_head(&child->mnt_hash, tree_list);
} else {
/*
* This can happen if the parent mount was bind mounted
* on some subdirectory of a shared/slave mount.
*/
- list_add_tail(&child->mnt_hash, &tmp_list);
+ hlist_add_head(&child->mnt_hash, &tmp_list);
}
prev_dest_mnt = m;
prev_src_mnt = child;
}
out:
lock_mount_hash();
- while (!list_empty(&tmp_list)) {
- child = list_first_entry(&tmp_list, struct mount, mnt_hash);
+ while (!hlist_empty(&tmp_list)) {
+ child = hlist_entry(tmp_list.first, struct mount, mnt_hash);
umount_tree(child, 0);
}
unlock_mount_hash();
@@ -338,8 +340,10 @@ static void __propagate_umount(struct mount *mnt)
* umount the child only if the child has no
* other children
*/
- if (child && list_empty(&child->mnt_mounts))
- list_move_tail(&child->mnt_hash, &mnt->mnt_hash);
+ if (child && list_empty(&child->mnt_mounts)) {
+ hlist_del_init_rcu(&child->mnt_hash);
+ hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash);
+ }
}
}
@@ -350,11 +354,11 @@ static void __propagate_umount(struct mount *mnt)
*
* vfsmount lock must be held for write
*/
-int propagate_umount(struct list_head *list)
+int propagate_umount(struct hlist_head *list)
{
struct mount *mnt;
- list_for_each_entry(mnt, list, mnt_hash)
+ hlist_for_each_entry(mnt, list, mnt_hash)
__propagate_umount(mnt);
return 0;
}