From: Colin Walters <walters@verbum.org>
Date: Sat, 14 Oct 2017 00:51:39 +0000 (-0400)
Subject: lib/deltas: Use pread() instead of lseek()+read()
X-Git-Tag: archive/raspbian/2022.1-3+rpi1~1^2~4^2~30^2~46
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=93457071cb5d47c08b60d3244f9632725634010a;p=ostree.git

lib/deltas: Use pread() instead of lseek()+read()

That's why the syscall was invented, so let's use it. Just noticed while reading
the code while working on another patch.

Closes: #1270
Approved by: jlebon
---

diff --git a/src/libostree/ostree-repo-static-delta-processing.c b/src/libostree/ostree-repo-static-delta-processing.c
index 6596da89..fac377ec 100644
--- a/src/libostree/ostree-repo-static-delta-processing.c
+++ b/src/libostree/ostree-repo-static-delta-processing.c
@@ -719,15 +719,13 @@ dispatch_write (OstreeRepo                 *repo,
     {
       if (state->read_source_fd != -1)
         {
-          if (lseek (state->read_source_fd, content_offset, SEEK_SET) == -1)
-            return glnx_throw_errno_prefix (error, "lseek");
           while (content_size > 0)
             {
               char buf[4096];
               gssize bytes_read;
 
               do
-                bytes_read = read (state->read_source_fd, buf, MIN(sizeof(buf), content_size));
+                bytes_read = pread (state->read_source_fd, buf, MIN(sizeof(buf), content_size), content_offset);
               while (G_UNLIKELY (bytes_read == -1 && errno == EINTR));
               if (bytes_read == -1)
                 return glnx_throw_errno_prefix (error, "read");