nbdkit/0034-file-Save-the-filename-or-equivalent-in-the-file-han.patch
2025-06-05 10:25:41 +01:00

242 lines
6.3 KiB
Diff

From 0d7f579afc815049a6a35e1ecdd34f1857b2784b Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 4 Jun 2025 21:00:47 +0100
Subject: [PATCH] file: Save the filename or equivalent in the file handle
This will allow us to improve error messages.
To make this change easier by reducing duplication, I also implemented
a common error path in the file_open function.
(cherry picked from commit 83ad77d28d598e4b85809e7225e754e64314f802)
---
plugins/file/file.c | 108 +++++++++++++++++++++++++-------------------
1 file changed, 62 insertions(+), 46 deletions(-)
diff --git a/plugins/file/file.c b/plugins/file/file.c
index b4dec3c5..f96d8a8c 100644
--- a/plugins/file/file.c
+++ b/plugins/file/file.c
@@ -493,6 +493,7 @@ file_list_exports (int readonly, int default_only,
/* The per-connection handle. */
struct handle {
int fd;
+ char *name; /* Filename or equivalent. */
struct stat statbuf;
bool is_block_device;
int sector_size;
@@ -548,7 +549,6 @@ static void *
file_open (int readonly)
{
struct handle *h;
- const char *file;
h = malloc (sizeof *h);
if (h == NULL) {
@@ -557,36 +557,44 @@ file_open (int readonly)
}
h->can_write = !readonly;
h->fd = -1;
+ h->name = NULL;
switch (mode) {
case mode_filename:
- file = filename;
- if (open_file_by_name (h, readonly, -1, file) == -1) {
- free (h);
- return NULL;
+ h->name = strdup (filename);
+ if (h->name == NULL) {
+ nbdkit_error ("strdup: %m");
+ goto err;
}
+ if (open_file_by_name (h, readonly, -1, h->name) == -1)
+ goto err;
break;
case mode_directory: {
int dfd;
+ const char *export_name = nbdkit_export_name ();
- file = nbdkit_export_name ();
- if (strchr (file, '/')) {
- nbdkit_error ("exportname cannot contain /");
- free (h);
+ if (export_name == NULL)
+ goto err;
+
+ h->name = strdup (export_name);
+ if (h->name == NULL) {
+ nbdkit_error ("strdup: %m");
+ goto err;
+ }
+ if (strchr (h->name, '/')) {
+ nbdkit_error ("%s: exportname cannot contain /", h->name);
errno = EINVAL;
- return NULL;
+ goto err;
}
dfd = open (directory, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
if (dfd == -1) {
nbdkit_error ("open %s: %m", directory);
- free (h);
- return NULL;
+ goto err;
}
- if (open_file_by_name (h, readonly, dfd, file) == -1) {
- free (h);
+ if (open_file_by_name (h, readonly, dfd, h->name) == -1) {
close (dfd);
- return NULL;
+ goto err;
}
close (dfd);
break;
@@ -595,14 +603,14 @@ file_open (int readonly)
case mode_fd: {
int r;
- /* This is needed for error messages. */
- file = "<file descriptor>";
-
+ if (asprintf (&h->name, "fd=%d", filedesc) == -1) {
+ nbdkit_error ("asprintf: %m");
+ goto err;
+ }
h->fd = dup (filedesc);
if (h->fd == -1) {
- nbdkit_error ("dup fd=%d: %m", filedesc);
- free (h);
- return NULL;
+ nbdkit_error ("dup: %s: %m", h->name);
+ goto err;
}
/* If the file descriptor is readonly then we should not advertise
@@ -610,10 +618,8 @@ file_open (int readonly)
*/
r = fcntl (h->fd, F_GETFL);
if (r == -1) {
- nbdkit_error ("fcntl: F_GETFL: %m");
- close (h->fd);
- free (h);
- return NULL;
+ nbdkit_error ("fcntl: %s: F_GETFL: %m", h->name);
+ goto err;
}
r &= O_ACCMODE;
if (r == O_RDONLY)
@@ -627,25 +633,30 @@ file_open (int readonly)
case mode_dirfd: {
int dfd;
+ const char *export_name = nbdkit_export_name ();
- file = nbdkit_export_name ();
- if (strchr (file, '/')) {
- nbdkit_error ("exportname cannot contain /");
- free (h);
+ if (export_name == NULL)
+ goto err;
+
+ h->name = strdup (export_name);
+ if (h->name == NULL) {
+ nbdkit_error ("strdup: %m");
+ goto err;
+ }
+ if (strchr (h->name, '/')) {
+ nbdkit_error ("%s: exportname cannot contain /", h->name);
errno = EINVAL;
- return NULL;
+ goto err;
}
/* We don't fork, so no need to worry about FD_CLOEXEC on the directory */
dfd = dup (filedesc);
if (dfd == -1) {
- nbdkit_error ("dup dirfd=%d: %m", filedesc);
- free (h);
- return NULL;
+ nbdkit_error ("dup: dirfd=%d: %m", filedesc);
+ goto err;
}
- if (open_file_by_name (h, readonly, dfd, file) == -1) {
- free (h);
+ if (open_file_by_name (h, readonly, dfd, h->name) == -1) {
close (dfd);
- return NULL;
+ goto err;
}
close (dfd);
break;
@@ -656,12 +667,11 @@ file_open (int readonly)
}
assert (h->fd >= 0);
+ assert (h->name != NULL);
if (fstat (h->fd, &h->statbuf) == -1) {
- nbdkit_error ("fstat: %s: %m", file);
- close (h->fd);
- free (h);
- return NULL;
+ nbdkit_error ("fstat: %s: %m", h->name);
+ goto err;
}
if (fadvise_mode != -1) {
@@ -669,7 +679,7 @@ file_open (int readonly)
#ifdef HAVE_POSIX_FADVISE
int r = posix_fadvise (h->fd, 0, 0, fadvise_mode);
if (r == -1)
- nbdkit_debug ("posix_fadvise: %s: %m (ignored)", file);
+ nbdkit_debug ("posix_fadvise: %s: %m (ignored)", h->name);
#else
nbdkit_debug ("fadvise is not supported");
#endif
@@ -680,17 +690,15 @@ file_open (int readonly)
else if (S_ISREG (h->statbuf.st_mode))
h->is_block_device = false;
else {
- nbdkit_error ("file is not regular or block device: %s", file);
- close (h->fd);
- free (h);
- return NULL;
+ nbdkit_error ("file is not regular or block device: %s", h->name);
+ goto err;
}
h->sector_size = 4096; /* Start with safe guess */
#ifdef BLKSSZGET
if (h->is_block_device) {
if (ioctl (h->fd, BLKSSZGET, &h->sector_size) == -1)
- nbdkit_debug ("cannot get sector size: %s: %m", file);
+ nbdkit_debug ("cannot get sector size: %s: %m", h->name);
}
#endif
@@ -711,6 +719,13 @@ file_open (int readonly)
h->can_blkdiscard = h->is_block_device;
return h;
+
+ err:
+ if (h->fd >= 0)
+ close (h->fd);
+ free (h->name);
+ free (h);
+ return NULL;
}
/* Free up the per-connection handle. */
@@ -723,6 +738,7 @@ file_close (void *handle)
remove_fd_from_window (h->fd);
#endif
close (h->fd);
+ free (h->name);
free (h);
}
--
2.47.1