From: Greg Kroah-Hartman Date: Mon, 18 Jun 2018 04:33:15 +0000 (+0200) Subject: 4.9-stable patches X-Git-Tag: v4.16.17~23 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b06ba588159ab809f8091f1670c14b33d5b39f07;p=thirdparty%2Fkernel%2Fstable-queue.git 4.9-stable patches added patches: btrfs-make-raid6-rebuild-retry-more.patch revert-btrfs-fix-scrub-to-repair-raid6-corruption.patch --- diff --git a/queue-4.9/btrfs-make-raid6-rebuild-retry-more.patch b/queue-4.9/btrfs-make-raid6-rebuild-retry-more.patch new file mode 100644 index 00000000000..9441e2edc2b --- /dev/null +++ b/queue-4.9/btrfs-make-raid6-rebuild-retry-more.patch @@ -0,0 +1,93 @@ +From Alexander.Levin@microsoft.com Mon Jun 18 06:32:04 2018 +From: Sasha Levin +Date: Fri, 15 Jun 2018 02:39:14 +0000 +Subject: Btrfs: make raid6 rebuild retry more +To: "gregkh@linuxfoundation.org" +Cc: "ben.hutchings@codethink.co.uk" , "stable@vger.kernel.org" , Liu Bo , David Sterba , Sasha Levin +Message-ID: <20180615023910.99232-2-alexander.levin@microsoft.com> + +From: Liu Bo + +[ Upstream commit 8810f7517a3bc4ca2d41d022446d3f5fd6b77c09 ] + +There is a scenario that can end up with rebuild process failing to +return good content, i.e. +suppose that all disks can be read without problems and if the content +that was read out doesn't match its checksum, currently for raid6 +btrfs at most retries twice, + +- the 1st retry is to rebuild with all other stripes, it'll eventually + be a raid5 xor rebuild, +- if the 1st fails, the 2nd retry will deliberately fail parity p so + that it will do raid6 style rebuild, + +however, the chances are that another non-parity stripe content also +has something corrupted, so that the above retries are not able to +return correct content, and users will think of this as data loss. +More seriouly, if the loss happens on some important internal btree +roots, it could refuse to mount. + +This extends btrfs to do more retries and each retry fails only one +stripe. Since raid6 can tolerate 2 disk failures, if there is one +more failure besides the failure on which we're recovering, this can +always work. + +The worst case is to retry as many times as the number of raid6 disks, +but given the fact that such a scenario is really rare in practice, +it's still acceptable. + +Signed-off-by: Liu Bo +Signed-off-by: David Sterba +Signed-off-by: Sasha Levin +Signed-off-by: Greg Kroah-Hartman +--- + fs/btrfs/raid56.c | 18 ++++++++++++++---- + fs/btrfs/volumes.c | 9 ++++++++- + 2 files changed, 22 insertions(+), 5 deletions(-) + +--- a/fs/btrfs/raid56.c ++++ b/fs/btrfs/raid56.c +@@ -2161,11 +2161,21 @@ int raid56_parity_recover(struct btrfs_r + } + + /* +- * reconstruct from the q stripe if they are +- * asking for mirror 3 ++ * Loop retry: ++ * for 'mirror == 2', reconstruct from all other stripes. ++ * for 'mirror_num > 2', select a stripe to fail on every retry. + */ +- if (mirror_num == 3) +- rbio->failb = rbio->real_stripes - 2; ++ if (mirror_num > 2) { ++ /* ++ * 'mirror == 3' is to fail the p stripe and ++ * reconstruct from the q stripe. 'mirror > 3' is to ++ * fail a data stripe and reconstruct from p+q stripe. ++ */ ++ rbio->failb = rbio->real_stripes - (mirror_num - 1); ++ ASSERT(rbio->failb > 0); ++ if (rbio->failb <= rbio->faila) ++ rbio->failb--; ++ } + + ret = lock_stripe_add(rbio); + +--- a/fs/btrfs/volumes.c ++++ b/fs/btrfs/volumes.c +@@ -5186,7 +5186,14 @@ int btrfs_num_copies(struct btrfs_fs_inf + else if (map->type & BTRFS_BLOCK_GROUP_RAID5) + ret = 2; + else if (map->type & BTRFS_BLOCK_GROUP_RAID6) +- ret = 3; ++ /* ++ * There could be two corrupted data stripes, we need ++ * to loop retry in order to rebuild the correct data. ++ * ++ * Fail a stripe at a time on every retry except the ++ * stripe under reconstruction. ++ */ ++ ret = map->num_stripes; + else + ret = 1; + free_extent_map(em); diff --git a/queue-4.9/revert-btrfs-fix-scrub-to-repair-raid6-corruption.patch b/queue-4.9/revert-btrfs-fix-scrub-to-repair-raid6-corruption.patch new file mode 100644 index 00000000000..fa2ee4d04c1 --- /dev/null +++ b/queue-4.9/revert-btrfs-fix-scrub-to-repair-raid6-corruption.patch @@ -0,0 +1,68 @@ +From Alexander.Levin@microsoft.com Mon Jun 18 06:31:44 2018 +From: Sasha Levin +Date: Fri, 15 Jun 2018 02:39:13 +0000 +Subject: Revert "Btrfs: fix scrub to repair raid6 corruption" +To: "gregkh@linuxfoundation.org" +Cc: "ben.hutchings@codethink.co.uk" , "stable@vger.kernel.org" , Sasha Levin +Message-ID: <20180615023910.99232-1-alexander.levin@microsoft.com> + +From: Sasha Levin + +This reverts commit 186a6519dc94964a4c5c68fca482f20f71551f26. + +This commit used an incorrect log message. + +Reported-by: Ben Hutchings +Signed-off-by: Sasha Levin +Signed-off-by: Greg Kroah-Hartman +--- + fs/btrfs/raid56.c | 18 ++++-------------- + fs/btrfs/volumes.c | 9 +-------- + 2 files changed, 5 insertions(+), 22 deletions(-) + +--- a/fs/btrfs/raid56.c ++++ b/fs/btrfs/raid56.c +@@ -2161,21 +2161,11 @@ int raid56_parity_recover(struct btrfs_r + } + + /* +- * Loop retry: +- * for 'mirror == 2', reconstruct from all other stripes. +- * for 'mirror_num > 2', select a stripe to fail on every retry. ++ * reconstruct from the q stripe if they are ++ * asking for mirror 3 + */ +- if (mirror_num > 2) { +- /* +- * 'mirror == 3' is to fail the p stripe and +- * reconstruct from the q stripe. 'mirror > 3' is to +- * fail a data stripe and reconstruct from p+q stripe. +- */ +- rbio->failb = rbio->real_stripes - (mirror_num - 1); +- ASSERT(rbio->failb > 0); +- if (rbio->failb <= rbio->faila) +- rbio->failb--; +- } ++ if (mirror_num == 3) ++ rbio->failb = rbio->real_stripes - 2; + + ret = lock_stripe_add(rbio); + +--- a/fs/btrfs/volumes.c ++++ b/fs/btrfs/volumes.c +@@ -5186,14 +5186,7 @@ int btrfs_num_copies(struct btrfs_fs_inf + else if (map->type & BTRFS_BLOCK_GROUP_RAID5) + ret = 2; + else if (map->type & BTRFS_BLOCK_GROUP_RAID6) +- /* +- * There could be two corrupted data stripes, we need +- * to loop retry in order to rebuild the correct data. +- * +- * Fail a stripe at a time on every retry except the +- * stripe under reconstruction. +- */ +- ret = map->num_stripes; ++ ret = 3; + else + ret = 1; + free_extent_map(em); diff --git a/queue-4.9/series b/queue-4.9/series index f87a32323c2..de87abba64c 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -8,3 +8,5 @@ net-qmi_wwan-add-netgear-aircard-779s.patch platform-x86-asus-wmi-fix-null-pointer-dereference.patch net-sonic-use-dma_mapping_error.patch net-dsa-b53-add-bcm5389-support.patch +revert-btrfs-fix-scrub-to-repair-raid6-corruption.patch +btrfs-make-raid6-rebuild-retry-more.patch