btrfs-progs: fix loop device mount checks

When creating a fs on a loop device, mkfs checks whether the same file
is not already mounted, but a backing file of another loop dev does not
exist, mkfs fails. This fixes a bug during openSUSE installation.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/utils.c b/utils.c
index f499023..81cae6d 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -831,11 +831,11 @@ static int is_same_blk_file(const char* a, const char* b)
        char real_a[PATH_MAX];
        char real_b[PATH_MAX];
 
-       if(!realpath(a, real_a) ||
-          !realpath(b, real_b))
-       {
-               return -errno;
-       }
+       if(!realpath(a, real_a))
+               strcpy(real_a, a);
+
+       if (!realpath(b, real_b))
+               strcpy(real_b, b);
 
        /* Identical path? */
        if(strcmp(real_a, real_b) == 0)
@@ -876,8 +876,8 @@ static int is_same_loop_file(const char* a, const char* b)
 {
        char res_a[PATH_MAX];
        char res_b[PATH_MAX];
-       const char* final_a;
-       const char* final_b;
+       const char* final_a = NULL;
+       const char* final_b = NULL;
        int ret;
 
        /* Resolve a if it is a loop device */
@@ -886,10 +886,13 @@ static int is_same_loop_file(const char* a, const char* b)
                        return 0;
                return ret;
        } else if (ret) {
-               if ((ret = resolve_loop_device(a, res_a, sizeof(res_a))) < 0)
-                       return ret;
-
-               final_a = res_a;
+               ret = resolve_loop_device(a, res_a, sizeof(res_a));
+               if (ret < 0) {
+                       if (errno != EPERM)
+                               return ret;
+               } else {
+                       final_a = res_a;
+               }
        } else {
                final_a = a;
        }
@@ -900,10 +903,13 @@ static int is_same_loop_file(const char* a, const char* b)
                        return 0;
                return ret;
        } else if (ret) {
-               if((ret = resolve_loop_device(b, res_b, sizeof(res_b))) < 0)
-                       return ret;
-
-               final_b = res_b;
+               ret = resolve_loop_device(b, res_b, sizeof(res_b));
+               if (ret < 0) {
+                       if (errno != EPERM)
+                               return ret;
+               } else {
+                       final_b = res_b;
+               }
        } else {
                final_b = b;
        }