When the size of acl extended attribution is larger than pre-allocated value buffer size, we will hit error '-ERANGE' and it's probabaly caused by concurrent get/set acl from different clients. In this case, current logic just sets acl to NULL so that we cannot get proper information but the operation looks successful. This patch adds retry logic for error -ERANGE and return -EIO if fail from the retry. Additionally, print real errno when failing from __ceph_getxattr(). Signed-off-by: Chengguang Xu <cgxu519@xxxxxxx> --- v2: - Increase retry count to 10. - Print real errno when failing from __ceph_getxattr(). fs/ceph/acl.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c index 59cb307b15fb..28290ac409d2 100644 --- a/fs/ceph/acl.c +++ b/fs/ceph/acl.c @@ -45,6 +45,7 @@ static inline void ceph_set_cached_acl(struct inode *inode, struct posix_acl *ceph_get_acl(struct inode *inode, int type) { int size; + unsigned int retry_cnt = 0; const char *name; char *value = NULL; struct posix_acl *acl; @@ -60,6 +61,7 @@ struct posix_acl *ceph_get_acl(struct inode *inode, int type) BUG(); } +retry: size = __ceph_getxattr(inode, name, "", 0); if (size > 0) { value = kzalloc(size, GFP_NOFS); @@ -68,12 +70,21 @@ struct posix_acl *ceph_get_acl(struct inode *inode, int type) size = __ceph_getxattr(inode, name, value, size); } - if (size > 0) + if (size == -ERANGE && retry_cnt < 10) { + retry_cnt++; + kfree(value); + value = NULL; + goto retry; + } + + if (size > 0) { acl = posix_acl_from_xattr(&init_user_ns, value, size); - else if (size == -ERANGE || size == -ENODATA || size == 0) + } else if (size == -ENODATA || size == 0) { acl = NULL; - else + } else { + pr_err_ratelimited("get acl failed, errno = %d\n", size); acl = ERR_PTR(-EIO); + } kfree(value); -- 2.17.1 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html