tar: remove unused externs, or make them static

[chaz/tar] / src / misc.c

diff --git a/src/misc.c b/src/misc.c
index b75f2ab4e419e4f9a928e75b25342630f2ad17ec..734dc4eded7adcac4f7a29d84111a0d49306cfb4 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -105,7 +105,7 @@ quote_copy_string (const char *string)
    completes the unquoting anyway.
 
    This is used for reading the saved directory file in incremental
-   dumps.  It is used for decoding old `N' records (demangling names).
+   dumps.  It is used for decoding old 'N' records (demangling names).
    But also, it is used for decoding file arguments, would they come
    from the shell or a -T file, and for decoding the --exclude
    argument.  */
@@ -616,6 +616,57 @@ deref_stat (char const *name, struct stat *buf)
   return fstatat (chdir_fd, name, buf, fstatat_flags);
 }
 
+/* Read from FD into the buffer BUF with COUNT bytes.  Attempt to fill
+   BUF.  Wait until input is available; this matters because files are
+   opened O_NONBLOCK for security reasons, and on some file systems
+   this can cause read to fail with errno == EAGAIN.  Return the
+   actual number of bytes read, zero for EOF, or
+   SAFE_READ_ERROR upon error.  */
+size_t
+blocking_read (int fd, void *buf, size_t count)
+{
+  size_t bytes = safe_read (fd, buf, count);
+
+#if defined F_SETFL && O_NONBLOCK
+  if (bytes == SAFE_READ_ERROR && errno == EAGAIN)
+    {
+      int flags = fcntl (fd, F_GETFL);
+      if (0 <= flags && flags & O_NONBLOCK
+         && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
+       bytes = safe_read (fd, buf, count);
+    }
+#endif
+
+  return bytes;
+}
+
+/* Write to FD from the buffer BUF with COUNT bytes.  Do a full write.
+   Wait until an output buffer is available; this matters because
+   files are opened O_NONBLOCK for security reasons, and on some file
+   systems this can cause write to fail with errno == EAGAIN.  Return
+   the actual number of bytes written, setting errno if that is less
+   than COUNT.  */
+size_t
+blocking_write (int fd, void const *buf, size_t count)
+{
+  size_t bytes = full_write (fd, buf, count);
+
+#if defined F_SETFL && O_NONBLOCK
+  if (bytes < count && errno == EAGAIN)
+    {
+      int flags = fcntl (fd, F_GETFL);
+      if (0 <= flags && flags & O_NONBLOCK
+         && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
+       {
+         char const *buffer = buf;
+         bytes += full_write (fd, buffer + bytes, count - bytes);
+       }
+    }
+#endif
+
+  return bytes;
+}
+
 /* Set FD's (i.e., assuming the working directory is PARENTFD, FILE's)
    access time to ATIME.  */
 int
@@ -662,7 +713,7 @@ static int wdcache[CHDIR_CACHE_SIZE];
 static size_t wdcache_count;
 
 int
-chdir_count ()
+chdir_count (void)
 {
   if (wd_count == 0)
     return wd_count;
@@ -763,11 +814,11 @@ chdir_do (int i)
          int prev = wdcache[0];
          for (ci = 1; prev != i; ci++)
            {
-             int curr = wdcache[ci];
+             int cur = wdcache[ci];
              wdcache[ci] = prev;
-             if (curr == i)
+             if (cur == i)
                break;
-             prev = curr;
+             prev = cur;
            }
          wdcache[0] = i;
        }
@@ -911,7 +962,7 @@ page_aligned_alloc (void **ptr, size_t size)
 
 struct namebuf
 {
-  char *buffer;                /* directory, `/', and directory member */
+  char *buffer;                /* directory, '/', and directory member */
   size_t buffer_size;  /* allocated size of name_buffer */
   size_t dir_length;   /* length of directory part in buffer */
 };