xfs: only return -errno or success from attr ->put_listent
Today, the put_listent formatters return either 1 or 0; if
they return 1, some callers treat this as an error and return
it up the stack, despite "1" not being a valid (negative)
error code.
The intent seems to be that if the input buffer is full,
we set seen_enough or set count = -1, and return 1;
but some callers check the return before checking the
seen_enough or count fields of the context.
Fix this by only returning non-zero for actual errors
encountered, and rely on the caller to first check the
return value, then check the values in the context to
decide what to do.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 110f1d7..f220129 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -146,7 +146,7 @@
arraytop = context->count + prefix_len + namelen + 1;
if (arraytop > context->firstu) {
context->count = -1; /* insufficient space */
- return 1;
+ return 0;
}
offset = (char *)context->alist + context->count;
strncpy(offset, prefix, prefix_len);
@@ -221,11 +221,15 @@
}
ssize_t
-xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)
+xfs_vn_listxattr(
+ struct dentry *dentry,
+ char *data,
+ size_t size)
{
struct xfs_attr_list_context context;
struct attrlist_cursor_kern cursor = { 0 };
- struct inode *inode = d_inode(dentry);
+ struct inode *inode = d_inode(dentry);
+ int error;
/*
* First read the regular on-disk attributes.
@@ -239,7 +243,9 @@
context.firstu = context.bufsize;
context.put_listent = xfs_xattr_put_listent;
- xfs_attr_list_int(&context);
+ error = xfs_attr_list_int(&context);
+ if (error)
+ return error;
if (context.count < 0)
return -ERANGE;