projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| ae9cf8e9 GKH |
1 | From b6c60c8018c4e9beb2f83fc82c09f9d033766571 Mon Sep 17 00:00:00 2001 |
| 2 | From: Josef Bacik <jbacik@fusionio.com> | |
| 3 | Date: Tue, 30 Jul 2013 16:30:30 -0400 | |
| 4 | Subject: Btrfs: change how we queue blocks for backref checking | |
| 5 | ||
| 6 | From: Josef Bacik <jbacik@fusionio.com> | |
| 7 | ||
| 8 | commit b6c60c8018c4e9beb2f83fc82c09f9d033766571 upstream. | |
| 9 | ||
| 10 | Previously we only added blocks to the list to have their backrefs checked if | |
| 11 | the level of the block is right above the one we are searching for. This is | |
| 12 | because we want to make sure we don't add the entire path up to the root to the | |
| 13 | lists to make sure we process things one at a time. This assumes that if any | |
| 14 | blocks in the path to the root are going to be not checked (shared in other | |
| 15 | words) then they will be in the level right above the current block on up. This | |
| 16 | isn't quite right though since we can have blocks higher up the list that are | |
| 17 | shared because they are attached to a reloc root. But we won't add this block | |
| 18 | to be checked and then later on we will BUG_ON(!upper->checked). So instead | |
| 19 | keep track of wether or not we've queued a block to be checked in this current | |
| 20 | search, and if we haven't go ahead and queue it to be checked. This patch fixed | |
| 21 | the panic I was seeing where we BUG_ON(!upper->checked). Thanks, | |
| 22 | ||
| 23 | Signed-off-by: Josef Bacik <jbacik@fusionio.com> | |
| 24 | Signed-off-by: Chris Mason <chris.mason@fusionio.com> | |
| 25 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 26 | ||
| 27 | --- | |
| 28 | fs/btrfs/relocation.c | 14 +++++++------- | |
| 29 | 1 file changed, 7 insertions(+), 7 deletions(-) | |
| 30 | ||
| 31 | --- a/fs/btrfs/relocation.c | |
| 32 | +++ b/fs/btrfs/relocation.c | |
| 33 | @@ -691,6 +691,7 @@ struct backref_node *build_backref_tree( | |
| 34 | int cowonly; | |
| 35 | int ret; | |
| 36 | int err = 0; | |
| 37 | + bool need_check = true; | |
| 38 | ||
| 39 | path1 = btrfs_alloc_path(); | |
| 40 | path2 = btrfs_alloc_path(); | |
| 41 | @@ -914,6 +915,7 @@ again: | |
| 42 | cur->bytenr); | |
| 43 | ||
| 44 | lower = cur; | |
| 45 | + need_check = true; | |
| 46 | for (; level < BTRFS_MAX_LEVEL; level++) { | |
| 47 | if (!path2->nodes[level]) { | |
| 48 | BUG_ON(btrfs_root_bytenr(&root->root_item) != | |
| 49 | @@ -957,14 +959,12 @@ again: | |
| 50 | ||
| 51 | /* | |
| 52 | * add the block to pending list if we | |
| 53 | - * need check its backrefs. only block | |
| 54 | - * at 'cur->level + 1' is added to the | |
| 55 | - * tail of pending list. this guarantees | |
| 56 | - * we check backrefs from lower level | |
| 57 | - * blocks to upper level blocks. | |
| 58 | + * need check its backrefs, we only do this once | |
| 59 | + * while walking up a tree as we will catch | |
| 60 | + * anything else later on. | |
| 61 | */ | |
| 62 | - if (!upper->checked && | |
| 63 | - level == cur->level + 1) { | |
| 64 | + if (!upper->checked && need_check) { | |
| 65 | + need_check = false; | |
| 66 | list_add_tail(&edge->list[UPPER], | |
| 67 | &list); | |
| 68 | } else |