fuse: fix nlink after unlink
Anand Avati reports that the following sequence of system calls fail on a fuse
filesystem:
create("filename") => 0
link("filename", "linkname") => 0
unlink("filename") => 0
link("linkname", "filename") => -ENOENT ### BUG ###
vfs_link() fails with ENOENT if i_nlink is zero, this is done to prevent
resurrecting already deleted files.
Fuse clears i_nlink on unlink even if there are other links pointing to the
file.
Reported-by: Anand Avati <avati@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 2066328..da37907 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -644,13 +644,12 @@
fuse_put_request(fc, req);
if (!err) {
struct inode *inode = entry->d_inode;
+ struct fuse_inode *fi = get_fuse_inode(inode);
- /*
- * Set nlink to zero so the inode can be cleared, if the inode
- * does have more links this will be discovered at the next
- * lookup/getattr.
- */
- clear_nlink(inode);
+ spin_lock(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ drop_nlink(inode);
+ spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
fuse_invalidate_attr(dir);
fuse_invalidate_entry_cache(entry);
@@ -762,8 +761,17 @@
will reflect changes in the backing inode (link count,
etc.)
*/
- if (!err || err == -EINTR)
+ if (!err) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ inc_nlink(inode);
+ spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
+ } else if (err == -EINTR) {
+ fuse_invalidate_attr(inode);
+ }
return err;
}