Attachment 75714 Details for Bug 9328 – A patch for _dbus_file_get_contents() to support procfs files that appear to be empty

[patch] A patch for _dbus_file_get_contents() to support procfs files that appear to be empty

0001-_dbus_file_get_contents-support-reading-from-procfs-.patch (text/plain), 2.36 KB, created by Krzysztof Konopko on 2013-02-28 22:43:07 UTC

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Creator: Krzysztof Konopko

Created: 2013-02-28 22:43:07 UTC

Size: 2.36 KB

patch

obsolete

>From b1c915155606da48678c124f2a1bde4a95a9ee61 Mon Sep 17 00:00:00 2001
>From: Krzysztof Konopko <krzysztof.konopko@youview.com>
>Date: Thu, 28 Feb 2013 22:33:55 +0000
>Subject: [PATCH] _dbus_file_get_contents() - support reading from procfs files
>
>For most procfs files (including process status file) fstat() returns size
>0.  See Notes on stat() manual page [1].
>
>This can be addressed but at least trying to read from a file that looks
>like an empty one and give up if no data is read.
>
>[1] http://man7.org/linux/man-pages/man2/stat.2.html
>---
> dbus/dbus-file-unix.c | 32 ++++++++++++++++++++++++++++++--
> 1 file changed, 30 insertions(+), 2 deletions(-)
>
>diff --git a/dbus/dbus-file-unix.c b/dbus/dbus-file-unix.c
>index 1975933..f82f78b 100644
>--- a/dbus/dbus-file-unix.c
>+++ b/dbus/dbus-file-unix.c
>@@ -60,6 +60,7 @@ _dbus_file_get_contents (DBusString       *str,
>   struct stat sb;
>   int orig_len;
>   int total;
>+  int bytes_read;
>   const char *filename_c;
> 
>   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
>@@ -104,11 +105,10 @@ _dbus_file_get_contents (DBusString       *str,
>     }
>   
>   total = 0;
>+  bytes_read = 0;
>   orig_len = _dbus_string_get_length (str);
>   if (sb.st_size > 0 && S_ISREG (sb.st_mode))
>     {
>-      int bytes_read;
>-
>       while (total < (int) sb.st_size)
>         {
>           bytes_read = _dbus_read (fd, str,
>@@ -145,6 +145,34 @@ _dbus_file_get_contents (DBusString       *str,
>     }
>   else
>     {
>+      /* Special file case when fstat() returns 0, e. g. a file in procfs */
>+      const size_t buffer_size = 512;
>+
>+      while ((bytes_read = _dbus_read (fd, str, buffer_size)))
>+        {
>+          if (bytes_read < 0)
>+            {
>+              dbus_set_error (error, _dbus_error_from_errno (errno),
>+                              "Error reading \"%s\": %s",
>+                              filename_c,
>+                              _dbus_strerror (errno));
>+
>+              _dbus_verbose ("read() failed: %s",
>+                             _dbus_strerror (errno));
>+
>+              _dbus_close (fd, NULL);
>+              _dbus_string_set_length (str, orig_len);
>+              return FALSE;
>+            }
>+          else
>+            total += bytes_read;
>+        }
>+
>+      /* OK, it was truly an empty file */
>+      if (total == 0)
>+        {
>+          _dbus_string_set_length (str, orig_len);
>+        }
>       _dbus_close (fd, NULL);
>       return TRUE;
>     }
>-- 
>1.8.1.2
>

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Attachments on bug 9328: 75714 | 76224 | 76666

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