Add kdump_set_filenames() as an easy API to set multiple names

Provide an easier-to-use API to set descriptive file names.

Signed-off-by: Petr Tesarik <petr@tesarici.cz>

include/libkdumpfile/kdumpfile.h.in

@@ -317,6 +317,18 @@ uint_fast32_t kdump_d32toh(kdump_ctx_t *ctx, uint_fast32_t val);
  */
 uint_fast64_t kdump_d64toh(kdump_ctx_t *ctx, uint_fast64_t val);
 
+/** Set descriptive file names.
+ * @param ctx    Dump file object.
+ * @param n      Number of names in @p names.
+ * @param names  Names. @c NULL means clear the name.
+ * @returns      Error status.
+ *
+ * Set the optional file names. These names are used in error messages to give
+ * humans a clue which file of a multi-file dump the error is related.
+ */
+kdump_status kdump_set_filenames(kdump_ctx_t *ctx, unsigned n,
+				 const char *const *names);
+
 /** Open a set of dump files.
  * @param ctx   Dump file object.
  * @param nfds  Number of file descriptors in @p fds.

src/kdumpfile/Makefile.am

@@ -62,7 +62,7 @@ libkdumpfile_la_LIBADD = \
 	$(SNAPPY_LIBS)	\
 	$(ZSTD_LIBS)
 
-libkdumpfile_la_LDFLAGS = -version-info 10:2:0
+libkdumpfile_la_LDFLAGS = -version-info 11:0:1
 
 if HAVE_LD_VERSION_SCRIPT
 libkdumpfile_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libkdumpfile.map

src/kdumpfile/libkdumpfile.map

@@ -12,6 +12,7 @@ LIBKDUMPFILE_0 {
     kdump_d32toh;
     kdump_d64toh;
 
+    kdump_set_filenames;
     kdump_open_fdset;
     kdump_read;
     kdump_read_string;

src/kdumpfile/open.c

@@ -376,6 +376,46 @@ clear_all_fds(kdump_ctx_t *ctx)
 	}
 }
 
+kdump_status
+kdump_set_filenames(kdump_ctx_t *ctx, unsigned n, const char *const *names)
+{
+	struct attr_data *dir;
+	kdump_status status;
+
+	clear_error(ctx);
+
+	if (get_num_files(ctx) < n &&
+	    (status = set_attr_number(ctx, gattr(ctx, GKI_num_files),
+				      ATTR_PERSIST, n)) != KDUMP_OK)
+		return set_error(ctx, status,
+				 "Cannot initialize file set size");
+
+	for (dir = gattr(ctx, GKI_dir_file_set)->dir; dir; dir = dir->next) {
+		struct attr_data *child;
+		unsigned fidx;
+
+		if (dir->template->type != KDUMP_DIRECTORY)
+			continue;
+		fidx = dir->template->fidx;
+		if (fidx >= n)
+			continue;
+		child = lookup_dir_attr(ctx->dict, dir, "name", 4);
+		if (!child)
+			continue;
+
+		if (names[fidx]) {
+			status = set_attr_string(ctx, child, ATTR_PERSIST,
+						 names[fidx]);
+			if (status != KDUMP_OK)
+				return set_error(ctx, status, "%s",
+						 err_filename(ctx, fidx));
+		} else
+			clear_attr(ctx, child);
+	}
+
+	return KDUMP_OK;
+}
+
 DEFINE_ALIAS(open_fdset);
 
 kdump_status

tests/fdset.c

@@ -205,6 +205,7 @@ main(int argc, char **argv)
 	kdump_attr_t attr;
 	kdump_ctx_t *ctx;
 	kdump_status status;
+	const char *names[2];
 	int fd;
 	int ret;
 	int rc;
@@ -555,6 +556,102 @@ main(int argc, char **argv)
 	else if (rc != TEST_OK)
 		ret = rc;
 
+	/*************************************************************
+	 * RESET.
+	 */
+	attr.type = KDUMP_NUMBER;
+	attr.val.number = 0;
+	status = kdump_attr_ref_set(ctx, &number, &attr);
+	if (status != KDUMP_OK) {
+		fprintf(stderr, "Cannot clean up the file set: %s\n",
+			kdump_get_err(ctx));
+		rc = TEST_FAIL;
+	}
+
+	/*************************************************************
+	 * Unset file names.
+	 */
+	names[0] = NULL;
+	names[1] = NULL;
+	status = kdump_set_filenames(ctx, 2, names);
+	if (status != KDUMP_OK) {
+		fprintf(stderr, "Cannot set file names: %s\n",
+			kdump_get_err(ctx));
+		rc = TEST_FAIL;
+	}
+
+	/* Check that fdset size is two. */
+	rc = check_fileset_size(ctx, 2);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
+	/* Check that file.set.0.name and file.set.1.name are unset */
+	rc = check_unset_file(ctx, &fileset, "0.name", KDUMP_STRING);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+	rc = check_unset_file(ctx, &fileset, "1.name", KDUMP_STRING);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
+	/*************************************************************
+	 * Real file names.
+	 */
+	names[0] = FILENAME_0;
+	names[1] = FILENAME_1;
+	status = kdump_set_filenames(ctx, 2, names);
+	if (status != KDUMP_OK) {
+		fprintf(stderr, "Cannot set file names: %s\n",
+			kdump_get_err(ctx));
+		rc = TEST_FAIL;
+	}
+
+	/* Check that fdset size is two. */
+	rc = check_fileset_size(ctx, 2);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
+	/* Verify file.set.0.name and file.set.1.name. */
+	rc = check_filename(ctx, &fileset, "0.name", FILENAME_0);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+	rc = check_filename(ctx, &fileset, "1.name", FILENAME_1);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
+	/* Set the file descriptor and reduce the set to one file. */
+	status = kdump_open_fd(ctx, fd);
+	if (status != KDUMP_OK && status != KDUMP_ERR_NOTIMPL) {
+		fprintf(stderr, "Cannot set dump file descriptor: %s\n",
+			kdump_get_err(ctx));
+		return TEST_ERR;
+	}
+
+	/* Verify file.set.0.name is still set. */
+	rc = check_filename(ctx, &fileset, "0.name", FILENAME_0);
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
+	/* But file.set.1.name no longer exists. */
+	rc = check_not_exist(ctx, &fileset, "1.name");
+	if (rc == TEST_ERR)
+		return rc;
+	else if (rc != TEST_OK)
+		ret = rc;
+
 	/*************************************************************
 	 * Clean up.
 	 */