From d8818fce6968e3cf42b017d47a23000bfb0cf906 Mon Sep 17 00:00:00 2001 From: Peter Wemm Date: Tue, 3 May 2016 00:09:13 +0000 Subject: [PATCH] Change a rounding operation that had missing braces into a roundup2() macro. Adjust the buffer clipping code to work as expected. This prevented a number of machines in the FreeBSD.org cluster from booting due to "ZFS: i/o error - all block copies unavailable" after an unclean shutdown. --- sys/boot/i386/zfsboot/zfsboot.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/sys/boot/i386/zfsboot/zfsboot.c b/sys/boot/i386/zfsboot/zfsboot.c index 928e41ab6767..2562aab5b59f 100644 --- a/sys/boot/i386/zfsboot/zfsboot.c +++ b/sys/boot/i386/zfsboot/zfsboot.c @@ -224,21 +224,18 @@ vdev_read(vdev_t *vdev, void *priv, off_t off, void *buf, size_t bytes) while (bytes > 0) { nb = bytes / DEV_BSIZE; - if (nb > READ_BUF_SIZE / DEV_BSIZE) - nb = READ_BUF_SIZE / DEV_BSIZE; /* * Ensure that the read size plus the leading offset does not * exceed the size of the read buffer. */ - if (nb * DEV_BSIZE + diff > READ_BUF_SIZE) - nb -= diff / DEV_BSIZE; + if (nb > (READ_BUF_SIZE - diff) / DEV_BSIZE) + nb = (READ_BUF_SIZE - diff) / DEV_BSIZE; /* * Round the number of blocks to read up to the nearest multiple * of DEV_GELIBOOT_BSIZE. */ - alignnb = nb + (diff / DEV_BSIZE) + - (DEV_GELIBOOT_BSIZE / DEV_BSIZE - 1) & ~ - (unsigned int)(DEV_GELIBOOT_BSIZE / DEV_BSIZE - 1); + alignnb = roundup2(nb * DEV_BSIZE + diff, DEV_GELIBOOT_BSIZE) + / DEV_BSIZE; if (drvread(dsk, dmadat->rdbuf, alignlba, alignnb)) return -1;