[PATCH] Fix oops in sysfs_hash_and_remove_file()

James Bottomley · Linus Torvalds · commit 36676bcbf9f6 · 2005-08-26T19:37:13.000-07:00
The problem arises if an entity in sysfs is created and removed without
ever having been made completely visible.  In SCSI this is triggered by
removing a device while it's initialising.

The problem appears to be that because it was never made visible in sysfs,
the sysfs dentry has a null d_inode which oopses when a reference is made
to it.  The solution is simply to check d_inode and assume the object was
never made visible (and thus doesn't need deleting) if it's NULL.

(akpm: possibly a stopgap for 2.6.13 scsi problems.  May not be the
long-term fix)

Signed-off-by: James Bottomley &lt;James.Bottomley@SteelEye.com&gt;
Cc: Greg KH &lt;greg@kroah.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
@@ -228,6 +228,10 @@ void sysfs_hash_and_remove(struct dentry * dir, const char * name)
 	struct sysfs_dirent * sd;
 	struct sysfs_dirent * parent_sd = dir->d_fsdata;
 
+	if (dir->d_inode == NULL)
+		/* no inode means this hasn't been made visible yet */
+		return;
+
 	down(&dir->d_inode->i_sem);
 	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
 		if (!sd->s_element)
