From 50322fe7d46b544d5649edb58bdbe5c95dd44b98 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 28 Feb 2006 16:59:03 -0800 Subject: [PATCH] [PATCH] fuse: fix bug in negative lookup If negative entries (nodeid == 0) were sent in reply to LOOKUP requests, two bugs could be triggered: - looking up a negative entry would return -EIO, - revaildate on an entry which turned negative would send a FORGET request with zero nodeid, which would cause an abort() in the library. The above would only happen if the 'negative_timeout=N' option was used, otherwise lookups reply -ENOENT, which worked correctly. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dir.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 21fd59c7bc..c72a8a9793 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -111,6 +111,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) /* Doesn't hurt to "reset" the validity timeout */ fuse_invalidate_entry_cache(entry); + + /* For negative dentries, always do a fresh lookup */ if (!inode) return 0; @@ -122,6 +124,9 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg); request_send(fc, req); err = req->out.h.error; + /* Zero nodeid is same as -ENOENT */ + if (!err && !outarg.nodeid) + err = -ENOENT; if (!err) { struct fuse_inode *fi = get_fuse_inode(inode); if (outarg.nodeid != get_node_id(inode)) { @@ -190,8 +195,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, fuse_lookup_init(req, dir, entry, &outarg); request_send(fc, req); err = req->out.h.error; - if (!err && ((outarg.nodeid && invalid_nodeid(outarg.nodeid)) || - !valid_mode(outarg.attr.mode))) + /* Zero nodeid is same as -ENOENT, but with valid timeout */ + if (!err && outarg.nodeid && + (invalid_nodeid(outarg.nodeid) || !valid_mode(outarg.attr.mode))) err = -EIO; if (!err && outarg.nodeid) { inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, -- 2.39.5