Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756298Ab3JCGT7 (ORCPT ); Thu, 3 Oct 2013 02:19:59 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:41568 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756271Ab3JCGT5 (ORCPT ); Thu, 3 Oct 2013 02:19:57 -0400 Date: Thu, 03 Oct 2013 07:19:56 +0100 To: torvalds@linux-foundation.org Subject: [PATCH 15/17] split __lookup_mnt() in two functions Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Al Viro Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4768 Lines: 147 Instead of passing the direction as argument (and checking it on every step through the hash chain), just have separate __lookup_mnt() and __lookup_mnt_last(). And use the standard iterators... Signed-off-by: Al Viro --- fs/mount.h | 3 ++- fs/namei.c | 4 ++-- fs/namespace.c | 44 ++++++++++++++++++++++++-------------------- fs/pnode.c | 6 +++--- 4 files changed, 31 insertions(+), 26 deletions(-) diff --git a/fs/mount.h b/fs/mount.h index 7076f25..f086607 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -77,7 +77,8 @@ static inline int is_mounted(struct vfsmount *mnt) return !IS_ERR_OR_NULL(real_mount(mnt)); } -extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int); +extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); +extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); static inline void get_mnt_ns(struct mnt_namespace *ns) { diff --git a/fs/namei.c b/fs/namei.c index 645268f..1f844fb 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1111,7 +1111,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, if (!d_mountpoint(path->dentry)) break; - mounted = __lookup_mnt(path->mnt, path->dentry, 1); + mounted = __lookup_mnt(path->mnt, path->dentry); if (!mounted) break; path->mnt = &mounted->mnt; @@ -1132,7 +1132,7 @@ static void follow_mount_rcu(struct nameidata *nd) { while (d_mountpoint(nd->path.dentry)) { struct mount *mounted; - mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1); + mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry); if (!mounted) break; nd->path.mnt = &mounted->mnt; diff --git a/fs/namespace.c b/fs/namespace.c index aa6dd93..8ae16b9f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -548,29 +548,33 @@ static void free_vfsmnt(struct mount *mnt) } /* - * find the first or last mount at @dentry on vfsmount @mnt depending on - * @dir. If @dir is set return the first mount else return the last mount. + * find the first mount at @dentry on vfsmount @mnt. * vfsmount_lock must be held for read or write. */ -struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry, - int dir) +struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) { struct list_head *head = mount_hashtable + hash(mnt, dentry); - struct list_head *tmp = head; - struct mount *p, *found = NULL; + struct mount *p; - for (;;) { - tmp = dir ? tmp->next : tmp->prev; - p = NULL; - if (tmp == head) - break; - p = list_entry(tmp, struct mount, mnt_hash); - if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) { - found = p; - break; - } - } - return found; + list_for_each_entry(p, head, mnt_hash) + if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) + return p; + return NULL; +} + +/* + * find the last mount at @dentry on vfsmount @mnt. + * vfsmount_lock must be held for read or write. + */ +struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry) +{ + struct list_head *head = mount_hashtable + hash(mnt, dentry); + struct mount *p; + + list_for_each_entry_reverse(p, head, mnt_hash) + if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) + return p; + return NULL; } /* @@ -594,7 +598,7 @@ struct vfsmount *lookup_mnt(struct path *path) struct mount *child_mnt; br_read_lock(&vfsmount_lock); - child_mnt = __lookup_mnt(path->mnt, path->dentry, 1); + child_mnt = __lookup_mnt(path->mnt, path->dentry); if (child_mnt) { mnt_add_count(child_mnt, 1); br_read_unlock(&vfsmount_lock); diff --git a/fs/pnode.c b/fs/pnode.c index 58933fd..c7221bb 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -310,7 +310,7 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) for (m = propagation_next(parent, parent); m; m = propagation_next(m, parent)) { - child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint, 0); + child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint); if (child && list_empty(&child->mnt_mounts) && (ret = do_refcount_check(child, 1))) break; @@ -332,8 +332,8 @@ static void __propagate_umount(struct mount *mnt) for (m = propagation_next(parent, parent); m; m = propagation_next(m, parent)) { - struct mount *child = __lookup_mnt(&m->mnt, - mnt->mnt_mountpoint, 0); + struct mount *child = __lookup_mnt_last(&m->mnt, + mnt->mnt_mountpoint); /* * umount the child only if the child has no * other children -- 1.7.2.5 -- 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/