[PATCH 4/5] cachefiles: correct the return value of cachefiles_check_volume_xattr()

[libaokun]

From: Baokun Li <libaok...@huawei.com>

In cachefiles_check_volume_xattr(), the error returned by vfs_getxattr is
not passed to ret, so it ends up returning -ESTALE, which leads to an
endless loop as follows:

cachefiles_acquire_volume
retry:
  cachefiles_check_volume_xattr
  // return -ESTALE
  cachefiles_bury_object
  //  EIO causes rename failure
  goto retry;

So pass the error code to ret when xlen < 0 to avoid the above problem.

Fixes: 32e150037dce ("fscache, cachefiles: Store the volume coherency data")
Signed-off-by: Baokun Li <libaok...@huawei.com>
---
 fs/cachefiles/xattr.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index bcb6173943ee..20e4a4391090 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -252,6 +252,7 @@ int cachefiles_check_volume_xattr(struct cachefiles_volume 
*volume)
                xlen = vfs_getxattr(&nop_mnt_idmap, dentry, 
cachefiles_xattr_cache, buf, len);
        if (xlen != len) {
                if (xlen < 0) {
+                       ret = xlen;
                        trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen,
                                                   
cachefiles_trace_getxattr_error);
                        if (xlen == -EIO)
-- 
2.39.2