X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbasic%2Fio-util.h;h=4684ed3bfc782919b71600521ba7a66f4b04043d;hp=5f77a556c047112ebffa183b7f573066a3686279;hb=5091db1fa99acdbc3d9acb485c1c70d8bfb636db;hpb=2b5cdb47b5a4a367bc2be8fe4457423f785884f0

diff --git a/src/basic/io-util.h b/src/basic/io-util.h
index 5f77a556c..4684ed3bf 100644
--- a/src/basic/io-util.h
+++ b/src/basic/io-util.h
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
 #pragma once
 
 /***
@@ -48,7 +46,7 @@ ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length);
                 char *_s = (char *)(s);         \
                 _i->iov_base = _s;              \
                 _i->iov_len = strlen(_s);       \
-        } while(false)
+        } while (false)
 
 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
         unsigned j;
@@ -77,3 +75,21 @@ static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 
         return k;
 }
+
+static inline bool FILE_SIZE_VALID(uint64_t l) {
+        /* ftruncate() and friends take an unsigned file size, but actually cannot deal with file sizes larger than
+         * 2^63 since the kernel internally handles it as signed value. This call allows checking for this early. */
+
+        return (l >> 63) == 0;
+}
+
+static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) {
+
+        /* Same as above, but allows one extra value: -1 as indication for infinity. */
+
+        if (l == (uint64_t) -1)
+                return true;
+
+        return FILE_SIZE_VALID(l);
+
+}