From 8462dd88ad3531837ebfccd17a083467faa40227 Mon Sep 17 00:00:00 2001 From: Amar Tumballi Date: Thu, 26 Feb 2009 08:09:25 -0800 Subject: volumefile modification awareness to make sure there are no inconsistencies. Complete (including feature to properly umount) in my sense. Signed-off-by: Anand V. Avati --- libglusterfs/src/common-utils.c | 51 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'libglusterfs/src/common-utils.c') diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c index 1b4106c41..e8a7c9ab5 100644 --- a/libglusterfs/src/common-utils.c +++ b/libglusterfs/src/common-utils.c @@ -1388,3 +1388,54 @@ gf_unlockfd (int fd) return fcntl (fd, F_SETLK, &fl); } +static void +compute_checksum (char *buf, size_t size, uint32_t *checksum) +{ + int ret = -1; + char *checksum_buf = NULL; + + checksum_buf = (char *)(checksum); + + if (!(*checksum)) { + checksum_buf [0] = 0xba; + checksum_buf [1] = 0xbe; + checksum_buf [2] = 0xb0; + checksum_buf [3] = 0x0b; + } + + for (ret = 0; ret < (size - 4); ret += 4) { + checksum_buf[0] ^= (buf[ret]); + checksum_buf[1] ^= (buf[ret + 1] << 1) ; + checksum_buf[2] ^= (buf[ret + 2] << 2); + checksum_buf[3] ^= (buf[ret + 3] << 3); + } + + for (ret = 0; ret <= (size % 4); ret++) { + checksum_buf[ret] ^= (buf[(size - 4) + ret] << ret); + } + + return; +} + +#define GF_CHECKSUM_BUF_SIZE 1024 + +int +get_checksum_for_file (int fd, uint32_t *checksum) +{ + int ret = -1; + char buf[GF_CHECKSUM_BUF_SIZE] = {0,}; + + /* goto first place */ + lseek (fd, 0L, SEEK_SET); + do { + ret = read (fd, &buf, GF_CHECKSUM_BUF_SIZE); + if (ret > 0) + compute_checksum (buf, GF_CHECKSUM_BUF_SIZE, + checksum); + } while (ret > 0); + + /* set it back */ + lseek (fd, 0L, SEEK_SET); + + return ret; +} -- cgit