staging: lustre: fix error deref in ll_splice_alias().
d_splice_alias() can return an ERR_PTR().
If it does while debugging is enabled, the following
CDEBUG() will dereference that error and crash.
So add appropriate checking, and provide a separate
debug message for the error case.
Reported-and-tested-by: James Simmons <jsimmons@infradead.org>
Fixes: e9d4f0b9f559 ("staging: lustre: llite: use d_splice_alias for directories.")
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
index 6c9ec46..9ac7f09 100644
--- a/drivers/staging/lustre/lustre/llite/namei.c
+++ b/drivers/staging/lustre/lustre/llite/namei.c
@@ -442,11 +442,16 @@
} else {
struct dentry *new = d_splice_alias(inode, de);
+ if (IS_ERR(new))
+ CDEBUG(D_DENTRY,
+ "splice inode %p as %pd gives error %lu\n",
+ inode, de, PTR_ERR(new));
if (new)
de = new;
}
- CDEBUG(D_DENTRY, "Add dentry %p inode %p refc %d flags %#x\n",
- de, d_inode(de), d_count(de), de->d_flags);
+ if (!IS_ERR(de))
+ CDEBUG(D_DENTRY, "Add dentry %p inode %p refc %d flags %#x\n",
+ de, d_inode(de), d_count(de), de->d_flags);
return de;
}