libbb: if opening /dev/loopN returns ENXIO, don't try N++.

function                                             old     new   delta
set_loop                                             639     635      -4

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/loop.c b/libbb/loop.c
index 823fba07952779d41d652b7762d6e96e6a44b7f0..c96c5e0700d527189a6d98e0798b9b9b9e59e2f7 100644 (file)
--- a/libbb/loop.c
+++ b/libbb/loop.c
@@ -94,19 +94,19 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse
 
        /* Open the file.  Barf if this doesn't work.  */
        mode = ro ? O_RDONLY : O_RDWR;
+ open_ffd:
        ffd = open(file, mode);
        if (ffd < 0) {
                if (mode != O_RDONLY) {
                        mode = O_RDONLY;
-                       ffd = open(file, mode);
+                       goto open_ffd;
                }
-               if (ffd < 0)
-                       return -errno;
+               return -errno;
        }
 
        /* Find a loop device.  */
        try = *device ? *device : dev;
-       /* 1048575 is a max possible minor number in Linux circa 2010 */
+       /* 1048575 (0xfffff) is a max possible minor number in Linux circa 2010 */
        for (i = 0; rc && i < 1048576; i++) {
                sprintf(dev, LOOP_FORMAT, i);
 
@@ -121,7 +121,7 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse
                                        goto try_to_open;
                        }
                        /* Ran out of block devices, return failure.  */
-                       rc = -ENOENT;
+                       rc = -1;
                        break;
                }
  try_to_open:
@@ -131,8 +131,14 @@ int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offse
                        mode = O_RDONLY;
                        dfd = open(try, mode);
                }
-               if (dfd < 0)
+               if (dfd < 0) {
+                       if (errno == ENXIO) {
+                               /* Happens if loop module is not loaded */
+                               rc = -1;
+                               break;
+                       }
                        goto try_again;
+               }
 
                rc = ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);