Add yet another tiny helper to manipulate flags

src/basic/btrfs-util.c

@@ -175,11 +175,7 @@ int btrfs_subvol_set_read_only_fd(int fd, bool b) {
         if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0)
                 return -errno;
 
-        if (b)
-                nflags = flags | BTRFS_SUBVOL_RDONLY;
-        else
-                nflags = flags & ~BTRFS_SUBVOL_RDONLY;
-
+        nflags = UPDATE_FLAG(flags, BTRFS_SUBVOL_RDONLY, b);
         if (flags == nflags)
                 return 0;
 

src/basic/fd-util.c

@@ -144,11 +144,7 @@ int fd_nonblock(int fd, bool nonblock) {
         if (flags < 0)
                 return -errno;
 
-        if (nonblock)
-                nflags = flags | O_NONBLOCK;
-        else
-                nflags = flags & ~O_NONBLOCK;
-
+        nflags = UPDATE_FLAG(flags, O_NONBLOCK, nonblock);
         if (nflags == flags)
                 return 0;
 
@@ -167,11 +163,7 @@ int fd_cloexec(int fd, bool cloexec) {
         if (flags < 0)
                 return -errno;
 
-        if (cloexec)
-                nflags = flags | FD_CLOEXEC;
-        else
-                nflags = flags & ~FD_CLOEXEC;
-
+        nflags = UPDATE_FLAG(flags, FD_CLOEXEC, cloexec);
         if (nflags == flags)
                 return 0;
 

src/basic/macro.h

@@ -451,8 +451,10 @@ static inline int __coverity_check_and_return__(int condition) {
                 ans;                                    \
         })
 
+#define UPDATE_FLAG(orig, flag, b)                      \
+        ((b) ? ((orig) | (flag)) : ((orig) & ~(flag)))
 #define SET_FLAG(v, flag, b) \
-        (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
+        (v) = UPDATE_FLAG(v, flag, b)
 #define FLAGS_SET(v, flags) \
         ((~(v) & (flags)) == 0)