From ed3815bbb5fc8003384793dc614ae9cd9d6db129 Mon Sep 17 00:00:00 2001 From: oetiker Date: Thu, 21 Apr 2011 06:12:50 +0000 Subject: [PATCH] fix rrd_create behaviour when mmaping on a full filesystem by actually 'filling' the file with zero. -- Francois-Xavier Bourlet francois-xavier.bourlet dotcloud.com git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.4@2181 a5681a0c-68f1-0310-ab6d-d61299d08faa --- program/src/rrd_open.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/program/src/rrd_open.c b/program/src/rrd_open.c index 2fc7d192..a99f0ab6 100644 --- a/program/src/rrd_open.c +++ b/program/src/rrd_open.c @@ -247,6 +247,38 @@ rrd_file_t *rrd_open( */ #ifdef HAVE_MMAP + /* force allocating the file on the underlaying filesystem to prevent any + * future bus error when the filesystem is full and attempting to write + * trough the file mapping. Filling the file using memset on the file + * mapping can also lead some bus error, so we use the old fashioned + * write(). + */ + if (rdwr & RRD_CREAT) { + char buf[4096]; + unsigned i; + + memset(buf, DNAN, sizeof buf); + lseek(rrd_simple_file->fd, offset, SEEK_SET); + + for (i = 0; i < (newfile_size - 1) / sizeof buf; ++i) + { + if (write(rrd_simple_file->fd, buf, sizeof buf) == -1) + { + rrd_set_error("write '%s': %s", file_name, rrd_strerror(errno)); + goto out_close; + } + } + + if (write(rrd_simple_file->fd, buf, + (newfile_size - 1) % sizeof buf) == -1) + { + rrd_set_error("write '%s': %s", file_name, rrd_strerror(errno)); + goto out_close; + } + + lseek(rrd_simple_file->fd, 0, SEEK_SET); + } + data = mmap(0, rrd_file->file_len, rrd_simple_file->mm_prot, rrd_simple_file->mm_flags, rrd_simple_file->fd, offset); @@ -259,7 +291,6 @@ rrd_file_t *rrd_open( } rrd_simple_file->file_start = data; if (rdwr & RRD_CREAT) { - memset(data, DNAN, newfile_size - 1); goto out_done; } #endif -- 2.30.2