[PATCH] Fix oops in sysfs_hash_and_remove_file()

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 <James.Bottomley@SteelEye.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index d727dc960634a28de3df914ccb26cdc63fac98a9..970a33f03299b12731401a55dbdbe2a1c547c3c0 100644 (file)
--- 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)