Use /dev/loop-control if possible (kernel 3.1).

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@605 36d66b0a-2a48-0410-832c-cd162a569da5

diff --git a/ChangeLog b/ChangeLog
index 90ee04f..5a7099d 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 2011-08-22  Milan Broz  <mbroz@redhat.com>
        * Add more paranoid checks for LUKS header and keyslot attributes.
        * Fix crypt_load to properly check device size.
+       * Use new /dev/loop-control (kernel 3.1) if possible.
 
 2011-07-25  Milan Broz  <mbroz@redhat.com>
        * Remove hash/hmac restart from crypto backend and make it part of hash/hmac final.

diff --git a/lib/utils_loop.c b/lib/utils_loop.c
index a1ed960..91cde56 100644 (file)
--- a/lib/utils_loop.c
+++ b/lib/utils_loop.c
@@ -29,11 +29,7 @@
 
 #include "utils_loop.h"
 
-#ifndef LOOP_CTL_GET_FREE
-#define LOOP_CTL_GET_FREE      0x4C82
-#endif
-
-char *crypt_loop_get_device(void)
+static char *crypt_loop_get_device_old(void)
 {
        char dev[20];
        int i, loop_fd;
@@ -60,8 +56,6 @@ char *crypt_loop_get_device(void)
        return NULL;
 }
 
-/* loop-control not yet upstream */
-#if 0
 char *crypt_loop_get_device(void)
 {
        char dev[64];
@@ -70,7 +64,7 @@ char *crypt_loop_get_device(void)
 
        loop_fd = open("/dev/loop-control", O_RDONLY);
        if (loop_fd < 0)
-               return NULL;
+               return crypt_loop_get_device_old();
 
        i = ioctl(loop_fd, LOOP_CTL_GET_FREE);
        if (i < 0) {
@@ -79,14 +73,14 @@ char *crypt_loop_get_device(void)
        }
        close(loop_fd);
 
-       snprintf(dev, "/dev/loop%d", i, sizeof(dev));
+       if (sprintf(dev, "/dev/loop%d", i) < 0)
+               return NULL;
 
        if (stat(dev, &st) || !S_ISBLK(st.st_mode))
                return NULL;
 
        return strdup(dev);
 }
-#endif
 
 int crypt_loop_attach(const char *loop, const char *file, int offset,
                      int autoclear, int *readonly)

diff --git a/lib/utils_loop.h b/lib/utils_loop.h
index 0deca04..67b9fac 100644 (file)
--- a/lib/utils_loop.h
+++ b/lib/utils_loop.h
@@ -9,6 +9,10 @@
 #define LO_FLAGS_AUTOCLEAR 4
 #endif
 
+#ifndef LOOP_CTL_GET_FREE
+#define LOOP_CTL_GET_FREE 0x4C82
+#endif
+
 char *crypt_loop_get_device(void);
 char *crypt_loop_backing_file(const char *loop);
 int crypt_loop_device(const char *loop);