code.ossystems Code Review - openembedded-core.git/blob

   1 Upstream-Status: Backport
   2 Signed-off-by: Jonathan Liu <net147@gmail.com>
   3
   4 From e3b6cb87e0ba1304fa07ec316784de1c6243b28e Mon Sep 17 00:00:00 2001
   5 From: Karel Zak <kzak@redhat.com>
   6 Date: Mon, 13 May 2013 10:54:41 +0200
   7 Subject: [PATCH] lib/loopdev: fix loopcxt_check_size() to work with blkdevs
   8
   9 The loopcxt_check_size() is workaround for kernels < v3.9, kernel has
  10 been fixed by commit 541c742a7559eb65f0e36d3e2338c2ca532a3e61.
  11
  12 The function sets loopdev size according to backing file size. The
  13 problem is that the backing file could be a block device where
  14 stat.st_size is zero, so we have to use blkdev_get_size() for block
  15 devices.
  16
  17 Addresses: https://bugs.archlinux.org/task/35193
  18 Reported-by: Dave Reisner <d@falconindy.com>
  19 Signed-off-by: Karel Zak <kzak@redhat.com>
  20 ---
  21  lib/loopdev.c | 16 +++++++++++++++-
  22  1 file changed, 15 insertions(+), 1 deletion(-)
  23
  24 diff --git a/lib/loopdev.c b/lib/loopdev.c
  25 index c35e306..3b65b5d 100644
  26 --- a/lib/loopdev.c
  27 +++ b/lib/loopdev.c
  28 @@ -1097,7 +1097,17 @@ static int loopcxt_check_size(struct loopdev_cxt *lc, int file_fd)
  29         if (fstat(file_fd, &st))
  30                 return -errno;
  31
  32 -       expected_size = st.st_size;
  33 +       if (S_ISBLK(st.st_mode)) {
  34 +               if (blkdev_get_size(file_fd,
  35 +                               (unsigned long long *) &expected_size))
  36 +                       return -errno;
  37 +       } else
  38 +               expected_size = st.st_size;
  39 +
  40 +       if (expected_size == 0 || expected_size <= lc->info.lo_offset) {
  41 +               DBG(lc, loopdev_debug("failed to determine expected size"));
  42 +               return 0;       /* ignore this error */
  43 +       }
  44
  45         if (lc->info.lo_offset > 0)
  46                 expected_size -= lc->info.lo_offset;
  47 @@ -1113,6 +1123,10 @@ static int loopcxt_check_size(struct loopdev_cxt *lc, int file_fd)
  48                 return -errno;
  49
  50         if (expected_size != size) {
  51 +               DBG(lc, loopdev_debug("warning: loopdev and expected "
  52 +                                     "size dismatch (%ju/%ju)",
  53 +                                     size, expected_size));
  54 +
  55                 if (loopcxt_set_capacity(lc)) {
  56                         /* ioctl not available */
  57                         if (errno == ENOTTY || errno == EINVAL)
  58 --
  59 1.8.2.3
  60