df: Set negative free space values to zero.

[collectd.git] / src / df.c

diff --git a/src/df.c b/src/df.c
index 2e9b2ae8288dd64f1a75d30b51d83593a8fd4ef8..9d53b0b67eb7c326d3b1811682144d2a7cb6b14b 100644 (file)
--- a/src/df.c
+++ b/src/df.c
@@ -280,7 +280,22 @@ static int df_read (void)
                        uint64_t blk_reserved;
                        uint64_t blk_used;
 
-                       /* Sanity-check for the values in the struct */
+                       /*
+                        * Sanity-check for the values in the struct
+                        */
+                       /* Check for negative "available" byes. For example UFS can
+                        * report negative free space for user. Notice. blk_reserved
+                        * will start to diminish after this. */
+#if HAVE_STATVFS
+                       /* Cast is needed to avoid compiler warnings.
+                        * ((struct statvfs).f_bavail is unsigned (POSIX)) */
+                       if (((int64_t) statbuf.f_bavail) < 0)
+                               statbuf.f_bavail = 0;
+#elif HAVE_STATFS
+                       if (statbuf.f_bavail < 0)
+                               statbuf.f_bavail = 0;
+#endif
+                       /* Make sure that f_blocks >= f_bfree >= f_bavail */
                        if (statbuf.f_bfree < statbuf.f_bavail)
                                statbuf.f_bfree = statbuf.f_bavail;
                        if (statbuf.f_blocks < statbuf.f_bfree)