Fix file copy not working when home drive is encrypted (sendfile fails to some reason with invalid argument)

1 files changed, 33 insertions, 10 deletions

diff --git a/main.c b/main.c
index 119f681..314d274 100644
--- a/main.c
+++ b/main.c
@@ -6,8 +6,8 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <sys/stat.h>
-#include <sys/sendfile.h>
 #include <sys/capability.h>
 
 #define KMS_SERVER_PROXY_FILEPATH "/var/lib/flatpak/app/com.dec05eba.gpu_screen_recorder/current/active/files/bin/kms-server-proxy"
@@ -88,19 +88,37 @@ static bool copy_file_atomic(const char *source_path, const char *dest_path) {
     snprintf(tmp_filepath, sizeof(tmp_filepath), "%s.tmp", dest_path);
 
     in_fd = open(source_path, O_RDONLY);
-    if(in_fd == -1)
+    if(in_fd == -1) {
+        fprintf(stderr, "Error: copy_file_atomic: failed to open %s, error: %s\n", source_path, strerror(errno));
         goto done;
+    }
 
-    struct stat st;
-    if(fstat(in_fd, &st) == -1)
+    out_fd = open(tmp_filepath, O_WRONLY | O_CREAT, 0755);
+    if(out_fd == -1) {
+        fprintf(stderr, "Error: copy_file_atomic: failed to create %s, error: %s\n", tmp_filepath, strerror(errno));
         goto done;
+    }
 
-    out_fd = open(tmp_filepath, O_RDWR | O_CREAT | O_TRUNC, 0755);
-    if(out_fd == -1)
-        goto done;
+    uint8_t buffer[8192];
+    for(;;) {
+        const ssize_t bytes_read = read(in_fd, buffer, sizeof(buffer));
+        if(bytes_read == -1) {
+            fprintf(stderr, "Error: copy_file_atomic: failed to read data from %s, error: %s\n", source_path, strerror(errno));
+            goto done;
+        } else if(bytes_read == 0) {
+            break;
+        }
 
-    if(sendfile(out_fd, in_fd, NULL, st.st_size) != st.st_size)
-        goto done;
+        ssize_t bytes_written_total = 0;
+        while(bytes_written_total < bytes_read) {
+            const ssize_t bytes_written = write(out_fd, buffer + bytes_written_total, bytes_read - bytes_written_total);
+            if(bytes_written == -1) {
+                fprintf(stderr, "Error: copy_file_atomic: failed to write data to %s, error: %s\n", tmp_filepath, strerror(errno));
+                goto done;
+            }
+            bytes_written_total += bytes_written;
+        }
+    }
 
     res = true;
 
@@ -110,8 +128,13 @@ static bool copy_file_atomic(const char *source_path, const char *dest_path) {
     if(out_fd)
         close(out_fd);
 
-    if(res)
+    if(res) {
         res = rename(tmp_filepath, dest_path) == 0;
+        if(!res)
+            fprintf(stderr, "Error: copy_file_atomic: Failed to rename from %s to %s, error: %s\n", strerror(errno), tmp_filepath, dest_path);
+    } else {
+        remove(tmp_filepath);
+    }
 
     return res;
 }