[PATCH v4] ceph: do not print the whole xattr value if it's too long

[PATCH v4] ceph: do not print the whole xattr value if it's too long

[xiubli]

From: Xiubo Li <xiubli@redhat.com>

If the xattr's value size is long enough the kernel will warn and
then will fail the xfstests test case.

Just print part of the value string if it's too long.

At the same time fix the function name issue in the debug logs.

URL: https://tracker.ceph.com/issues/58404
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---

V4:
- fix the function name issue in the debug logs
- make the logs to be more compact.

 fs/ceph/xattr.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index b10d459c2326..5ab4aed2eecc 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -561,6 +561,8 @@ static struct ceph_vxattr *ceph_match_vxattr(struct inode *inode,
 	return NULL;
 }
 
+#define MAX_XATTR_VAL_PRINT_LEN 256
+
 static int __set_xattr(struct ceph_inode_info *ci,
 			   const char *name, int name_len,
 			   const char *val, int val_len,
@@ -623,7 +625,7 @@ static int __set_xattr(struct ceph_inode_info *ci,
 		xattr->should_free_name = update_xattr;
 
 		ci->i_xattrs.count++;
-		dout("__set_xattr count=%d\n", ci->i_xattrs.count);
+		dout("%s count=%d\n", __func__, ci->i_xattrs.count);
 	} else {
 		kfree(*newxattr);
 		*newxattr = NULL;
@@ -651,11 +653,13 @@ static int __set_xattr(struct ceph_inode_info *ci,
 	if (new) {
 		rb_link_node(&xattr->node, parent, p);
 		rb_insert_color(&xattr->node, &ci->i_xattrs.index);
-		dout("__set_xattr_val p=%p\n", p);
+		dout("%s p=%p\n", __func__, p);
 	}
 
-	dout("__set_xattr_val added %llx.%llx xattr %p %.*s=%.*s\n",
-	     ceph_vinop(&ci->netfs.inode), xattr, name_len, name, val_len, val);
+	dout("%s added %llx.%llx xattr %p %.*s=%.*s%s\n", __func__,
+	     ceph_vinop(&ci->netfs.inode), xattr, name_len, name,
+	     min(val_len, MAX_XATTR_VAL_PRINT_LEN), val,
+	     val_len > MAX_XATTR_VAL_PRINT_LEN ? "..." : "");
 
 	return 0;
 }
@@ -681,13 +685,15 @@ static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
 		else if (c > 0)
 			p = &(*p)->rb_right;
 		else {
-			dout("__get_xattr %s: found %.*s\n", name,
-			     xattr->val_len, xattr->val);
+			int len = min(xattr->val_len, MAX_XATTR_VAL_PRINT_LEN);
+
+			dout("%s %s: found %.*s%s\n", __func__, name, len,
+			     xattr->val, xattr->val_len > len ? "..." : "");
 			return xattr;
 		}
 	}
 
-	dout("__get_xattr %s: not found\n", name);
+	dout("%s %s: not found\n", __func__, name);
 
 	return NULL;
 }
-- 
2.31.1

Re: [PATCH v4] ceph: do not print the whole xattr value if it's too long

[Ilya Dryomov]

On Thu, Mar 2, 2023 at 1:26 PM <xiubli@redhat.com> wrote:
>
> From: Xiubo Li <xiubli@redhat.com>
>
> If the xattr's value size is long enough the kernel will warn and
> then will fail the xfstests test case.
>
> Just print part of the value string if it's too long.
>
> At the same time fix the function name issue in the debug logs.
>
> URL: https://tracker.ceph.com/issues/58404
> Signed-off-by: Xiubo Li <xiubli@redhat.com>
> ---
>
> V4:
> - fix the function name issue in the debug logs
> - make the logs to be more compact.
>
>  fs/ceph/xattr.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
> index b10d459c2326..5ab4aed2eecc 100644
> --- a/fs/ceph/xattr.c
> +++ b/fs/ceph/xattr.c
> @@ -561,6 +561,8 @@ static struct ceph_vxattr *ceph_match_vxattr(struct inode *inode,
>         return NULL;
>  }
>
> +#define MAX_XATTR_VAL_PRINT_LEN 256
> +
>  static int __set_xattr(struct ceph_inode_info *ci,
>                            const char *name, int name_len,
>                            const char *val, int val_len,
> @@ -623,7 +625,7 @@ static int __set_xattr(struct ceph_inode_info *ci,
>                 xattr->should_free_name = update_xattr;
>
>                 ci->i_xattrs.count++;
> -               dout("__set_xattr count=%d\n", ci->i_xattrs.count);
> +               dout("%s count=%d\n", __func__, ci->i_xattrs.count);
>         } else {
>                 kfree(*newxattr);
>                 *newxattr = NULL;
> @@ -651,11 +653,13 @@ static int __set_xattr(struct ceph_inode_info *ci,
>         if (new) {
>                 rb_link_node(&xattr->node, parent, p);
>                 rb_insert_color(&xattr->node, &ci->i_xattrs.index);
> -               dout("__set_xattr_val p=%p\n", p);
> +               dout("%s p=%p\n", __func__, p);
>         }
>
> -       dout("__set_xattr_val added %llx.%llx xattr %p %.*s=%.*s\n",
> -            ceph_vinop(&ci->netfs.inode), xattr, name_len, name, val_len, val);
> +       dout("%s added %llx.%llx xattr %p %.*s=%.*s%s\n", __func__,
> +            ceph_vinop(&ci->netfs.inode), xattr, name_len, name,
> +            min(val_len, MAX_XATTR_VAL_PRINT_LEN), val,
> +            val_len > MAX_XATTR_VAL_PRINT_LEN ? "..." : "");
>
>         return 0;
>  }
> @@ -681,13 +685,15 @@ static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
>                 else if (c > 0)
>                         p = &(*p)->rb_right;
>                 else {
> -                       dout("__get_xattr %s: found %.*s\n", name,
> -                            xattr->val_len, xattr->val);
> +                       int len = min(xattr->val_len, MAX_XATTR_VAL_PRINT_LEN);
> +
> +                       dout("%s %s: found %.*s%s\n", __func__, name, len,
> +                            xattr->val, xattr->val_len > len ? "..." : "");
>                         return xattr;
>                 }
>         }
>
> -       dout("__get_xattr %s: not found\n", name);
> +       dout("%s %s: not found\n", __func__, name);
>
>         return NULL;
>  }
> --
> 2.31.1
>

Reviewed-by: Ilya Dryomov <idryomov@gmail.com>

Thanks,

                Ilya