Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753745AbbEGKZl (ORCPT ); Thu, 7 May 2015 06:25:41 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47768 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460AbbEGJsO (ORCPT ); Thu, 7 May 2015 05:48:14 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Eric W. Biederman" , Luis Henriques Subject: [PATCH 3.16.y-ckt 089/180] mnt: Improve the umount_tree flags Date: Thu, 7 May 2015 10:44:58 +0100 Message-Id: <1430991989-23170-90-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> References: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5091 Lines: 156 3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit e819f152104c9f7c9fe50e1aecce6f5d4bf06d65 upstream. - 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. Signed-off-by: "Eric W. Biederman" [ luis: backported to 3.16: - dropped change to __detach_mounts() ] Signed-off-by: Luis Henriques --- fs/namespace.c | 29 +++++++++++++++-------------- fs/pnode.h | 1 - 2 files changed, 15 insertions(+), 15 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index b1a14ad2ca01..d74c67678bb1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1258,14 +1258,15 @@ 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; @@ -1279,7 +1280,7 @@ 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) { @@ -1287,7 +1288,7 @@ 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)) { put_mountpoint(p->mnt_mp); @@ -1391,14 +1392,14 @@ 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; } } @@ -1566,7 +1567,7 @@ 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; @@ -1590,7 +1591,7 @@ 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(); } @@ -1746,7 +1747,7 @@ 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); @@ -1921,7 +1922,7 @@ 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: @@ -2292,7 +2293,7 @@ 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(); @@ -2363,7 +2364,7 @@ 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 4a246358b031..16afc3d6d2f2 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/