4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Sandeen <[email protected]> commit 2a6fba6d2311151598abaa1e7c9abd5f8d024a43 upstream. 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 <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Dave Chinner <[email protected]> Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/xfs/xfs_attr.h | 1 + fs/xfs/xfs_attr_list.c | 8 +++----- fs/xfs/xfs_xattr.c | 15 ++++++++++----- 3 files changed, 14 insertions(+), 10 deletions(-) --- a/fs/xfs/xfs_attr.h +++ b/fs/xfs/xfs_attr.h @@ -112,6 +112,7 @@ typedef struct attrlist_cursor_kern { *========================================================================*/ +/* Return 0 on success, or -errno; other state communicated via *context */ typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int, unsigned char *, int, int, unsigned char *); --- a/fs/xfs/xfs_attr_list.c +++ b/fs/xfs/xfs_attr_list.c @@ -108,16 +108,14 @@ xfs_attr_shortform_list(xfs_attr_list_co (int)sfe->namelen, (int)sfe->valuelen, &sfe->nameval[sfe->namelen]); - + if (error) + return error; /* * Either search callback finished early or * didn't fit it all in the buffer after all. */ if (context->seen_enough) break; - - if (error) - return error; sfe = XFS_ATTR_SF_NEXTENTRY(sfe); } trace_xfs_attr_list_sf_all(context); @@ -581,7 +579,7 @@ xfs_attr_put_listent( trace_xfs_attr_list_full(context); alist->al_more = 1; context->seen_enough = 1; - return 1; + return 0; } aep = (attrlist_ent_t *)&context->alist[context->firstu]; --- a/fs/xfs/xfs_xattr.c +++ b/fs/xfs/xfs_xattr.c @@ -180,7 +180,7 @@ xfs_xattr_put_listent( 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, xfs_xattr_prefix(flags), prefix_len); @@ -222,12 +222,15 @@ list_one_attr(const char *name, const si } 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); - int error; + struct inode *inode = d_inode(dentry); + int error; /* * First read the regular on-disk attributes. @@ -245,7 +248,9 @@ xfs_vn_listxattr(struct dentry *dentry, else context.put_listent = xfs_xattr_put_listent_sizes; - xfs_attr_list_int(&context); + error = xfs_attr_list_int(&context); + if (error) + return error; if (context.count < 0) return -ERANGE;
