From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Damien Le Moal Subject: [PATCH] zbd: Fix zone report handling Date: Fri, 19 Apr 2019 12:40:49 +0900 Message-Id: <20190419034049.10226-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: fio@vger.kernel.org, Jens Axboe Cc: Shinichiro Kawasaki List-ID: fio may be executed concurrently with a block device revalidation by the kernel. Device revalidation may lead to the block device capacity to be changed to a smaller value (device changed) or to even 0 in case of revalidation failure. In such case, the BLKREPORTZONE ioctl executed from read_zone_info() may report a success with an empty zone report when the start sector for the report is above the new capacity of the device. This leads to an infinite loop inside parse_zone_info() and the fio run never terminating. Fix this problem by returning -EIO from read_zone_info() thus avoiding the infinite loop in parse_zone_info(). This change does not affect the normal case with a stable device as read_zone_info() is always called with a valid start sector that does not result in an empty zone report. Signed-off-by: Damien Le Moal --- zbd.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/zbd.c b/zbd.c index 2da742b7..1c46b452 100644 --- a/zbd.c +++ b/zbd.c @@ -186,11 +186,14 @@ static bool zbd_verify_bs(void) * size of @buf. * * Returns 0 upon success and a negative error code upon failure. + * If the zone report is empty, always assume an error (device problem) and + * return -EIO. */ static int read_zone_info(int fd, uint64_t start_sector, void *buf, unsigned int bufsz) { struct blk_zone_report *hdr = buf; + int ret; if (bufsz < sizeof(*hdr)) return -EINVAL; @@ -199,7 +202,12 @@ static int read_zone_info(int fd, uint64_t start_sector, hdr->nr_zones = (bufsz - sizeof(*hdr)) / sizeof(struct blk_zone); hdr->sector = start_sector; - return ioctl(fd, BLKREPORTZONE, hdr) >= 0 ? 0 : -errno; + ret = ioctl(fd, BLKREPORTZONE, hdr); + if (ret) + return -errno; + if (!hdr->nr_zones) + return -EIO; + return 0; } /* -- 2.20.1