From: Vishal Verma Date: Thu, 31 Aug 2017 01:36:00 +0000 (-0600) Subject: libnvdimm, btt: ensure that flags were also unchanged during a map_read X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1398199d849047c59acef0c04e550b47bb9b4be6;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git libnvdimm, btt: ensure that flags were also unchanged during a map_read In btt_map_read, we read the map twice to make sure that the map entry didn't change after we added it to the read tracking table. In anticipation of expanding the use of the error bit, also make sure that the error and zero flags are constant across the two map reads. Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index bb816bc1a906..15d1b071746b 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1032,6 +1032,7 @@ static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, */ while (1) { u32 new_map; + int new_t, new_e; if (t_flag) { zero_fill_data(page, off, cur_len); @@ -1050,15 +1051,18 @@ static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, */ barrier(); - ret = btt_map_read(arena, premap, &new_map, &t_flag, - &e_flag, NVDIMM_IO_ATOMIC); + ret = btt_map_read(arena, premap, &new_map, &new_t, + &new_e, NVDIMM_IO_ATOMIC); if (ret) goto out_rtt; - if (postmap == new_map) + if ((postmap == new_map) && (t_flag == new_t) && + (e_flag == new_e)) break; postmap = new_map; + t_flag = new_t; + e_flag = new_e; } ret = btt_data_read(arena, page, off, postmap, cur_len);