From 8dc51fe5ab9edcaebb5438d6462befdc6922b4a1 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Thu, 23 Jan 2014 15:55:01 -0800 Subject: [PATCH] autofs: fix symlinks aren't checked for expiry The autofs4 module doesn't consider symlinks for expire as it did in the older autofs v3 module (so it's actually a long standing regression). The user space daemon has focused on the use of bind mounts instead of symlinks for a long time now and that's why this has not been noticed. But with the future addition of amd map parsing to automount(8), not to mention amd itself (of am-utils), symlink expiry will be needed. The direct and offset mount types can't be symlinks and the tree mounts of version 4 were always real mounts so only indirect mounts need expire symlinks. Since the current users of the autofs4 module haven't reported this as a problem to date this patch probably isn't a candidate for backport to stable. Signed-off-by: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/autofs4/expire.c | 14 ++++++++++++++ fs/autofs4/symlink.c | 4 ++++ 2 files changed, 18 insertions(+) diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 3d9d3f5d5dda..394e90b02c5e 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -402,6 +402,20 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, goto next; } + if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) { + DPRINTK("checking symlink %p %.*s", + dentry, (int)dentry->d_name.len, dentry->d_name.name); + /* + * A symlink can't be "busy" in the usual sense so + * just check last used for expire timeout. + */ + if (autofs4_can_expire(dentry, timeout, do_now)) { + expired = dentry; + goto found; + } + goto next; + } + if (simple_empty(dentry)) goto next; diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c index f27c094a1919..1e8ea192be2b 100644 --- a/fs/autofs4/symlink.c +++ b/fs/autofs4/symlink.c @@ -14,6 +14,10 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) { + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino && !autofs4_oz_mode(sbi)) + ino->last_used = jiffies; nd_set_link(nd, dentry->d_inode->i_private); return NULL; } -- 2.20.1