[PATCH v2 proxmox-backup 3/3] fix #7658: client: pxar: skip files on fstatat permission errors

[Robert Obkircher <r.obkircher@proxmox.com>]

Log a warning instead of aborting the entire backup if fstatat returns
a permission error. This is preferable when running backups without
full knowledge or control over the contents [1, 2] and consistent with
how we treat EACCES when opening files.

Note that it was already possible to explicitly exclude such files[3].

[1] https://bugzilla.proxmox.com/show_bug.cgi?id=7658
[2] https://forum.proxmox.com/threads/182315
[3] https://bugzilla.proxmox.com/show_bug.cgi?id=4380

Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
---
 pbs-client/src/pxar/create.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pbs-client/src/pxar/create.rs b/pbs-client/src/pxar/create.rs
index 2492eaf00..cb66b70b8 100644
--- a/pbs-client/src/pxar/create.rs
+++ b/pbs-client/src/pxar/create.rs
@@ -710,6 +710,11 @@ impl Archiver {
                     warn!("warning: file vanished while reading directory: {full_path:?}");
                     continue;
                 }
+                Err(Errno::EACCES) => {
+                    // may happen for fuse mountpoints without allow_other or allow_root
+                    warn!("warning: failed to stat file: {full_path:?}: access denied");
+                    continue;
+                }
                 Err(Errno::ESTALE) => {
                     self.report_stale_file_handle(Some(&full_path));
                     continue;
-- 
2.47.3