From 53f5fa4e1f560475dadbefc1f00e0f3d2ca84ca0 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 4 Jun 2025 21:03:58 +0100
Subject: [PATCH] file: Add the filename (or equivalent) to error messages

It helps to have this information when there's an error.  It
particularly helps in two cases: (1) You don't have access to the
nbdkit command line.  (2) The filename is derived from an export name
passed by the client.

(cherry picked from commit 7273bd829fc0d8e492786f8908d8ddc3d5399e06)
---
 plugins/file/file.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/plugins/file/file.c b/plugins/file/file.c
index 4dec4bd9..8018b294 100644
--- a/plugins/file/file.c
+++ b/plugins/file/file.c
@@ -797,7 +797,7 @@ file_get_size (void *handle)
 
   r = device_size (h->fd, &h->statbuf);
   if (r == -1) {
-    nbdkit_error ("device_size: %m");
+    nbdkit_error ("device_size: %s: %m", h->name);
     return -1;
   }
   return r;
@@ -883,7 +883,7 @@ file_flush (void *handle, uint32_t flags)
   struct handle *h = handle;
 
   if (fdatasync (h->fd) == -1) {
-    nbdkit_error ("fdatasync: %m");
+    nbdkit_error ("fdatasync: %s: %m", h->name);
     return -1;
   }
 
@@ -904,11 +904,11 @@ file_pread (void *handle, void *buf, uint32_t count, uint64_t offset,
   while (count > 0) {
     ssize_t r = pread (h->fd, buf, count, offset);
     if (r == -1) {
-      nbdkit_error ("pread: %m");
+      nbdkit_error ("pread: %s: %m", h->name);
       return -1;
     }
     if (r == 0) {
-      nbdkit_error ("pread: unexpected end of file");
+      nbdkit_error ("pread: %s: unexpected end of file", h->name);
       return -1;
     }
     buf += r;
@@ -940,7 +940,7 @@ file_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset,
   while (count > 0) {
     ssize_t r = pwrite (h->fd, buf, count, offset);
     if (r == -1) {
-      nbdkit_error ("pwrite: %m");
+      nbdkit_error ("pwrite: %s: %m", h->name);
       return -1;
     }
     buf += r;
@@ -1022,7 +1022,7 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
     }
 
     if (!is_enotsup (errno)) {
-      nbdkit_error ("zero: %m");
+      nbdkit_error ("zero: %s: %m", h->name);
       return -1;
     }
 
@@ -1058,7 +1058,7 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
       }
 
       if (!is_enotsup (errno)) {
-        nbdkit_error ("zero: %m");
+        nbdkit_error ("zero: %s: %m", h->name);
         return -1;
       }
 
@@ -1066,7 +1066,7 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
     }
     else {
       if (!is_enotsup (errno)) {
-        nbdkit_error ("zero: %m");
+        nbdkit_error ("zero: %s: %m", h->name);
         return -1;
       }
 
@@ -1088,7 +1088,7 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
     }
 
     if (!is_enotsup (errno)) {
-      nbdkit_error ("zero: %m");
+      nbdkit_error ("zero: %s: %m", h->name);
       return -1;
     }
 
@@ -1116,14 +1116,14 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
       }
 
       if (!is_enotsup (errno)) {
-        nbdkit_error ("zero: %m");
+        nbdkit_error ("zero: %s: %m", h->name);
         return -1;
       }
 
       h->can_fallocate = false;
     } else {
       if (!is_enotsup (errno)) {
-        nbdkit_error ("zero: %m");
+        nbdkit_error ("zero: %s: %m", h->name);
         return -1;
       }
 
@@ -1147,7 +1147,7 @@ file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
     }
 
     if (errno != ENOTTY) {
-      nbdkit_error ("zero: %m");
+      nbdkit_error ("zero: %s: %m", h->name);
       return -1;
     }
 
@@ -1185,7 +1185,7 @@ file_trim (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
       /* Trim is advisory; we don't care if it fails for anything other
        * than EIO or EPERM. */
       if (errno == EPERM || errno == EIO) {
-        nbdkit_error ("fallocate: %m");
+        nbdkit_error ("fallocate: %s: %m", h->name);
         return -1;
       }
 
@@ -1306,7 +1306,7 @@ file_cache (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
   r = posix_fadvise (h->fd, offset, count, POSIX_FADV_WILLNEED);
   if (r) {
     errno = r;
-    nbdkit_error ("posix_fadvise: %m");
+    nbdkit_error ("posix_fadvise: %s: %m", h->name);
     return -1;
   }
   return 0;
-- 
2.47.1