diff options
Diffstat (limited to 'kernels/linux-libre-rt/3.12-btrfs-relocate-csums.patch')
| -rw-r--r-- | kernels/linux-libre-rt/3.12-btrfs-relocate-csums.patch | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/kernels/linux-libre-rt/3.12-btrfs-relocate-csums.patch b/kernels/linux-libre-rt/3.12-btrfs-relocate-csums.patch new file mode 100644 index 000000000..7209276ef --- /dev/null +++ b/kernels/linux-libre-rt/3.12-btrfs-relocate-csums.patch @@ -0,0 +1,63 @@ +From 4577b014d1bc3db386da3246f625888fc48083a9 Mon Sep 17 00:00:00 2001 +From: Josef Bacik <jbacik@fusionio.com> +Date: Fri, 27 Sep 2013 13:33:09 +0000 +Subject: Btrfs: relocate csums properly with prealloc extents + +A user reported a problem where they were getting csum errors when running a +balance and running systemd's journal. This is because systemd is awesome and +fallocate()'s its log space and writes into it. Unfortunately we assume that +when we read in all the csums for an extent that they are sequential starting at +the bytenr we care about. This obviously isn't the case for prealloc extents, +where we could have written to the middle of the prealloc extent only, which +means the csum would be for the bytenr in the middle of our range and not the +front of our range. Fix this by offsetting the new bytenr we are logging to +based on the original bytenr the csum was for. With this patch I no longer see +the csum errors I was seeing. Thanks, + +Cc: stable@vger.kernel.org +Reported-by: Chris Murphy <lists@colorremedies.com> +Signed-off-by: Josef Bacik <jbacik@fusionio.com> +Signed-off-by: Chris Mason <chris.mason@fusionio.com> +--- +diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c +index dec4f5a..0359eec 100644 +--- a/fs/btrfs/relocation.c ++++ b/fs/btrfs/relocation.c +@@ -4472,6 +4472,7 @@ int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + u64 disk_bytenr; ++ u64 new_bytenr; + LIST_HEAD(list); + + ordered = btrfs_lookup_ordered_extent(inode, file_pos); +@@ -4483,13 +4484,24 @@ int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) + if (ret) + goto out; + +- disk_bytenr = ordered->start; + while (!list_empty(&list)) { + sums = list_entry(list.next, struct btrfs_ordered_sum, list); + list_del_init(&sums->list); + +- sums->bytenr = disk_bytenr; +- disk_bytenr += sums->len; ++ /* ++ * We need to offset the new_bytenr based on where the csum is. ++ * We need to do this because we will read in entire prealloc ++ * extents but we may have written to say the middle of the ++ * prealloc extent, so we need to make sure the csum goes with ++ * the right disk offset. ++ * ++ * We can do this because the data reloc inode refers strictly ++ * to the on disk bytes, so we don't have to worry about ++ * disk_len vs real len like with real inodes since it's all ++ * disk length. ++ */ ++ new_bytenr = ordered->start + (sums->bytenr - disk_bytenr); ++ sums->bytenr = new_bytenr; + + btrfs_add_ordered_sum(inode, ordered, sums); + } +-- +cgit v0.9.2 |