From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit e819f152104c9f7c9fe50e1aecce6f5d4bf06d65 ]
- Remove the unneeded declaration from pnode.h
- Mark umount_tree static as it has no callers outside of namespace.c
- Define an enumeration of umount_tree's flags.
- Pass umount_tree's flags in by name
This removes the magic numbers 0, 1 and 2 making the code a little
clearer and makes it possible for there to be lazy unmounts that don't
propagate. Which is what __detach_mounts actually wants for example.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
fs/namespace.c | 31 ++++++++++++++++---------------
fs/pnode.h | 1 -
2 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index bbde147..7ea7e51 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1322,14 +1322,15 @@ static inline void namespace_lock(void)
down_write(&namespace_sem);
}
+enum umount_tree_flags {
+ UMOUNT_SYNC = 1,
+ UMOUNT_PROPAGATE = 2,
+};
/*
* mount_lock must be held
* namespace_sem must be held for write
- * how = 0 => just this tree, don't propagate
- * how = 1 => propagate; we know that nobody else has reference to any victims
- * how = 2 => lazy umount
*/
-void umount_tree(struct mount *mnt, int how)
+static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
{
HLIST_HEAD(tmp_list);
struct mount *p;
@@ -1343,7 +1344,7 @@ void umount_tree(struct mount *mnt, int how)
hlist_for_each_entry(p, &tmp_list, mnt_hash)
list_del_init(&p->mnt_child);
- if (how)
+ if (how & UMOUNT_PROPAGATE)
propagate_umount(&tmp_list);
hlist_for_each_entry(p, &tmp_list, mnt_hash) {
@@ -1351,7 +1352,7 @@ void umount_tree(struct mount *mnt, int how)
list_del_init(&p->mnt_list);
__touch_mnt_namespace(p->mnt_ns);
p->mnt_ns = NULL;
- if (how < 2)
+ if (how & UMOUNT_SYNC)
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
if (mnt_has_parent(p)) {
hlist_del_init(&p->mnt_mp_list);
@@ -1456,14 +1457,14 @@ static int do_umount(struct mount *mnt, int flags)
if (flags & MNT_DETACH) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 2);
+ umount_tree(mnt, UMOUNT_PROPAGATE);
retval = 0;
} else {
shrink_submounts(mnt);
retval = -EBUSY;
if (!propagate_mount_busy(mnt, 2)) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 1);
+ umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
retval = 0;
}
}
@@ -1495,7 +1496,7 @@ void __detach_mounts(struct dentry *dentry)
lock_mount_hash();
while (!hlist_empty(&mp->m_list)) {
mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
- umount_tree(mnt, 2);
+ umount_tree(mnt, UMOUNT_PROPAGATE);
}
unlock_mount_hash();
put_mountpoint(mp);
@@ -1662,7 +1663,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
out:
if (res) {
lock_mount_hash();
- umount_tree(res, 0);
+ umount_tree(res, UMOUNT_SYNC);
unlock_mount_hash();
}
return q;
@@ -1686,7 +1687,7 @@ void drop_collected_mounts(struct vfsmount *mnt)
{
namespace_lock();
lock_mount_hash();
- umount_tree(real_mount(mnt), 0);
+ umount_tree(real_mount(mnt), UMOUNT_SYNC);
unlock_mount_hash();
namespace_unlock();
}
@@ -1869,7 +1870,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
out_cleanup_ids:
while (!hlist_empty(&tree_list)) {
child = hlist_entry(tree_list.first, struct mount, mnt_hash);
- umount_tree(child, 0);
+ umount_tree(child, UMOUNT_SYNC);
}
unlock_mount_hash();
cleanup_group_ids(source_mnt, NULL);
@@ -2046,7 +2047,7 @@ static int do_loopback(struct path *path, const char *old_name,
err = graft_tree(mnt, parent, mp);
if (err) {
lock_mount_hash();
- umount_tree(mnt, 0);
+ umount_tree(mnt, UMOUNT_SYNC);
unlock_mount_hash();
}
out2:
@@ -2417,7 +2418,7 @@ void mark_mounts_for_expiry(struct list_head *mounts)
while (!list_empty(&graveyard)) {
mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
touch_mnt_namespace(mnt->mnt_ns);
- umount_tree(mnt, 1);
+ umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
}
unlock_mount_hash();
namespace_unlock();
@@ -2488,7 +2489,7 @@ static void shrink_submounts(struct mount *mnt)
m = list_first_entry(&graveyard, struct mount,
mnt_expire);
touch_mnt_namespace(m->mnt_ns);
- umount_tree(m, 1);
+ umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC);
}
}
}
diff --git a/fs/pnode.h b/fs/pnode.h
index 4a24635..16afc3d 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -47,7 +47,6 @@ int get_dominating_id(struct mount *mnt, const struct path *root);
unsigned int mnt_get_count(struct mount *mnt);
void mnt_set_mountpoint(struct mount *, struct mountpoint *,
struct mount *);
-void umount_tree(struct mount *, int);
struct mount *copy_tree(struct mount *, struct dentry *, int);
bool is_path_reachable(struct mount *, struct dentry *,
const struct path *root);
--
2.1.0
--
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