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Commit 287548e4 authored by Al Viro's avatar Al Viro
Browse files

split __follow_mount_rcu() into normal and .. cases 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent dc7acbb2

fs/namei.c

+26 −9
Original line number Diff line number Diff line
@@ -919,12 +919,11 @@ static inline bool managed_dentry_might_block(struct dentry *dentry) 
}



/*

 * Skip to top of mountpoint pile in rcuwalk mode.  We abort the rcu-walk if we

 * meet a managed dentry and we're not walking to "..".  True is returned to

 * continue, false to abort.

 * Try to skip to top of mountpoint pile in rcuwalk mode.  Fail if

 * we meet a managed dentry that would need blocking.

 */

static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,

			       struct inode **inode, bool reverse_transit)

			       struct inode **inode)

{

	for (;;) {

		struct vfsmount *mounted;
@@ -933,8 +932,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, 
		 * that wants to block transit.

		 */

		*inode = path->dentry->d_inode;

		if (!reverse_transit &&

		     unlikely(managed_dentry_might_block(path->dentry)))

		if (unlikely(managed_dentry_might_block(path->dentry)))

			return false;



		if (!d_mountpoint(path->dentry))
@@ -949,10 +947,29 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, 
	}



	if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))

		return reverse_transit;

		return false;

	return true;

}



static void follow_mount_rcu(struct nameidata *nd, struct path *path,

			       struct inode **inode)

{

	for (;;) {

		struct vfsmount *mounted;

		*inode = path->dentry->d_inode;



		if (!d_mountpoint(path->dentry))

			break;



		mounted = __lookup_mnt(path->mnt, path->dentry, 1);

		if (!mounted)

			break;

		path->mnt = mounted;

		path->dentry = mounted->mnt_root;

		nd->seq = read_seqcount_begin(&path->dentry->d_seq);

	}

}



static int follow_dotdot_rcu(struct nameidata *nd)

{

	struct inode *inode = nd->inode;
@@ -982,7 +999,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);

		inode = nd->path.dentry->d_inode;

	}

	__follow_mount_rcu(nd, &nd->path, &inode, true);

	follow_mount_rcu(nd, &nd->path, &inode);

	nd->inode = inode;

	return 0;
@@ -1157,7 +1174,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, 
		}

		path->mnt = mnt;

		path->dentry = dentry;

		if (likely(__follow_mount_rcu(nd, path, inode, false)))

		if (likely(__follow_mount_rcu(nd, path, inode)))

			return 0;

unlazy:

		if (unlazy_walk(nd, dentry))