From 02f2b12475d685b7badb4335ff6cf2da6c4ae719 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Tue, 26 May 2015 11:56:39 -0300 Subject: linux-libre-knock-4.0.4_gnu-2: add proposed fix for data loss on md raid0 when discard is used (FS#45040 -> https://bugs.archlinux.org/task/45040) --- ...x-restore-to-sector-variable-in-raid0_mak.patch | 50 ++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 kernels/linux-libre-knock/md-raid0-fix-restore-to-sector-variable-in-raid0_mak.patch (limited to 'kernels/linux-libre-knock/md-raid0-fix-restore-to-sector-variable-in-raid0_mak.patch') diff --git a/kernels/linux-libre-knock/md-raid0-fix-restore-to-sector-variable-in-raid0_mak.patch b/kernels/linux-libre-knock/md-raid0-fix-restore-to-sector-variable-in-raid0_mak.patch new file mode 100644 index 000000000..9f09102dc --- /dev/null +++ b/kernels/linux-libre-knock/md-raid0-fix-restore-to-sector-variable-in-raid0_mak.patch @@ -0,0 +1,50 @@ +From a81157768a00e8cf8a7b43b5ea5cac931262374f Mon Sep 17 00:00:00 2001 +From: Eric Work +Date: Mon, 18 May 2015 23:26:23 -0700 +Subject: [PATCH] md/raid0: fix restore to sector variable in + raid0_make_request + +The variable "sector" in "raid0_make_request()" was improperly updated +by a call to "sector_div()" which modifies its first argument in place. +Commit 47d68979cc968535cb87f3e5f2e6a3533ea48fbd restored this variable +after the call for later re-use. Unfortunetly the restore was done after +the referenced variable "bio" was advanced. This lead to the original +value and the restored value being different. Here we move this line to +the proper place. + +One observed side effect of this bug was discarding a file though +unlinking would cause an unrelated file's contents to be discarded. + +Signed-off-by: NeilBrown +Fixes: 47d68979cc96 ("md/raid0: fix bug with chunksize not a power of 2.") +Cc: stable@vger.kernel.org (any that received above backport) +URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501 +--- + drivers/md/raid0.c | 4 +++- + 1 file changed, 3 insertions(+), 1 deletion(-) + +diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c +index 6a68ef5..efb654e 100644 +--- a/drivers/md/raid0.c ++++ b/drivers/md/raid0.c +@@ -524,6 +524,9 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio) + ? (sector & (chunk_sects-1)) + : sector_div(sector, chunk_sects)); + ++ /* Restore due to sector_div */ ++ sector = bio->bi_iter.bi_sector; ++ + if (sectors < bio_sectors(bio)) { + split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set); + bio_chain(split, bio); +@@ -531,7 +534,6 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio) + split = bio; + } + +- sector = bio->bi_iter.bi_sector; + zone = find_zone(mddev->private, §or); + tmp_dev = map_sector(mddev, zone, sector, §or); + split->bi_bdev = tmp_dev->bdev; +-- +2.4.1 + -- cgit v1.2.3