61 lines
1.5 KiB
Diff
61 lines
1.5 KiB
Diff
diff -uNr qemu-2.12.0/lockf_implementation.h qemu-2.12.0.mod/lockf_implementation.h
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--- qemu-2.12.0/lockf_implementation.h 1970-01-01 03:00:00.000000000 +0300
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+++ qemu-2.12.0.mod/lockf_implementation.h 2018-06-25 14:11:33.263965456 +0300
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@@ -0,0 +1,56 @@
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+#ifndef LOCKF_IMPLEMENTATION_H
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+#define LOCKF_IMPLEMENTATION_H
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+
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+//
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+// lockf() implementation from GNU Libc
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+//
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+
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+static int lockf (int fd, int cmd, off_t len)
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+{
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+ struct flock fl;
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+
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+ memset ((char *) &fl, '\0', sizeof (fl));
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+
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+ /* lockf is always relative to the current file position. */
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+ fl.l_whence = SEEK_CUR;
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+ fl.l_start = 0;
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+ fl.l_len = len;
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+
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+ switch (cmd)
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+ {
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+ case F_TEST:
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+ /* Test the lock: return 0 if FD is unlocked or locked by this process;
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+ return -1, set errno to EACCES, if another process holds the lock. */
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+ fl.l_type = F_RDLCK;
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+ if (fcntl (fd, F_GETLK, &fl) < 0)
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+ return -1;
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+ if (fl.l_type == F_UNLCK || fl.l_pid == getpid ())
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+ return 0;
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+ errno = EACCES;
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+ return -1;
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+
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+ case F_ULOCK:
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+ fl.l_type = F_UNLCK;
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+ cmd = F_SETLK;
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+ break;
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+ case F_LOCK:
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+ fl.l_type = F_WRLCK;
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+ cmd = F_SETLKW;
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+ break;
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+ case F_TLOCK:
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+ fl.l_type = F_WRLCK;
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+ cmd = F_SETLK;
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+ break;
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+
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+ default:
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+ errno = EINVAL;
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+ return -1;
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+ }
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+
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+ /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
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+ used. Therefore we don't have to care about cancellation here,
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+ the fcntl() function will take care of it. */
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+ return fcntl (fd, cmd, &fl);
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+}
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+
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+#endif
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