From: Michal Privoznik <mprivozn@redhat.com>
Date: Tue, 1 Mar 2022 08:35:48 +0000 (+0100)
Subject: lxc_fuse: Tell FUSE that /proc/meminfo is nonseekable
X-Git-Tag: v8.2.0-rc1~175
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=766495508650bebd5f4ac23224ecd0a2ee2ca9eb;p=thirdparty%2Flibvirt.git

lxc_fuse: Tell FUSE that /proc/meminfo is nonseekable

If an app within a container wishes to read from /proc/meminfo
from a different position than the beginning of the file, we can
have FUSE keep track of all the lseek()-s and reflect them in
@offset argument of read callback (lxcProcRead()). This is done
by setting fuse_file_info::nonseekable. If we don't do this, then
FUSE reports errors back the app that does lseek().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---

diff --git a/src/lxc/lxc_fuse.c b/src/lxc/lxc_fuse.c
index 73d3ab1015..181b05b605 100644
--- a/src/lxc/lxc_fuse.c
+++ b/src/lxc/lxc_fuse.c
@@ -118,6 +118,7 @@ lxcProcOpen(const char *path,
         return -EACCES;
 
     fi->direct_io = 1;
+    fi->nonseekable = 1;
     return 0;
 }