* [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items
@ 2021-07-19 5:43 Qu Wenruo
2021-07-19 5:52 ` Su Yue
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Qu Wenruo @ 2021-07-19 5:43 UTC (permalink / raw)
To: linux-btrfs; +Cc: Zhenyu Wu
When extent tree gets corrupted, normally it's not extent tree root, but
one toasted tree leaf/node.
In that case, rescue=ibadroots mount option won't help as it can only
handle the extent tree root corruption.
This patch will enhance the behavior by:
- Allow fill_dummy_bgs() to ignore -EEXIST error
This means we may have some block group items read from disk, but
then hit some error halfway.
- Fallback to fill_dummy_bgs() if any error gets hit in
btrfs_read_block_groups()
Of course, this still needs rescue=ibadroots mount option.
With that, rescue=ibadroots can handle extent tree corruption more
gracefully and allow a better recover chance.
Reported-by: Zhenyu Wu <wuzy001@gmail.com>
Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
Changelog:
v2:
- Don't try to fill with dummy block groups when we hit ENOMEM
v3:
- Remove a dead condition
The empty fs_info->extent_root case has already been handled.
v4:
- Skip to next block group if we hit EEXIST when inserting the block
group cache
---
fs/btrfs/block-group.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 5bd76a45037e..758ba856f8c6 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2105,11 +2105,22 @@ static int fill_dummy_bgs(struct btrfs_fs_info *fs_info)
bg->used = em->len;
bg->flags = map->type;
ret = btrfs_add_block_group_cache(fs_info, bg);
+ /*
+ * We may have some valid block group cache added already, in
+ * that case we skip to next bg.
+ */
+ if (ret == -EEXIST) {
+ ret = 0;
+ btrfs_put_block_group(bg);
+ continue;
+ }
+
if (ret) {
btrfs_remove_free_space_cache(bg);
btrfs_put_block_group(bg);
break;
}
+
btrfs_update_space_info(fs_info, bg->flags, em->len, em->len,
0, 0, &space_info);
bg->space_info = space_info;
@@ -2212,6 +2223,14 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
ret = check_chunk_block_group_mappings(info);
error:
btrfs_free_path(path);
+ /*
+ * We hit some error reading the extent tree, and have rescue=ibadroots
+ * mount option.
+ * Try to fill using dummy block groups so that the user can continue
+ * to mount and grab their data.
+ */
+ if (ret && btrfs_test_opt(info, IGNOREBADROOTS))
+ ret = fill_dummy_bgs(info);
return ret;
}
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items
2021-07-19 5:43 [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items Qu Wenruo
@ 2021-07-19 5:52 ` Su Yue
2021-07-19 8:19 ` Anand Jain
2021-07-21 17:33 ` David Sterba
2 siblings, 0 replies; 4+ messages in thread
From: Su Yue @ 2021-07-19 5:52 UTC (permalink / raw)
To: Qu Wenruo; +Cc: linux-btrfs, Zhenyu Wu
On Mon 19 Jul 2021 at 13:43, Qu Wenruo <wqu@suse.com> wrote:
> When extent tree gets corrupted, normally it's not extent tree
> root, but
> one toasted tree leaf/node.
>
> In that case, rescue=ibadroots mount option won't help as it can
> only
> handle the extent tree root corruption.
>
> This patch will enhance the behavior by:
>
> - Allow fill_dummy_bgs() to ignore -EEXIST error
>
> This means we may have some block group items read from disk,
> but
> then hit some error halfway.
>
> - Fallback to fill_dummy_bgs() if any error gets hit in
> btrfs_read_block_groups()
>
> Of course, this still needs rescue=ibadroots mount option.
>
> With that, rescue=ibadroots can handle extent tree corruption
> more
> gracefully and allow a better recover chance.
>
> Reported-by: Zhenyu Wu <wuzy001@gmail.com>
> Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html
> Signed-off-by: Qu Wenruo <wqu@suse.com>
>
LGTM.
Reviewed-by: Su Yue <l@damenly.su>
--
Su
> ---
> Changelog:
> v2:
> - Don't try to fill with dummy block groups when we hit ENOMEM
> v3:
> - Remove a dead condition
> The empty fs_info->extent_root case has already been handled.
> v4:
> - Skip to next block group if we hit EEXIST when inserting the
> block
> group cache
> ---
> fs/btrfs/block-group.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index 5bd76a45037e..758ba856f8c6 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -2105,11 +2105,22 @@ static int fill_dummy_bgs(struct
> btrfs_fs_info *fs_info)
> bg->used = em->len;
> bg->flags = map->type;
> ret = btrfs_add_block_group_cache(fs_info, bg);
> + /*
> + * We may have some valid block group cache added already,
> in
> + * that case we skip to next bg.
> + */
> + if (ret == -EEXIST) {
> + ret = 0;
> + btrfs_put_block_group(bg);
> + continue;
> + }
> +
> if (ret) {
> btrfs_remove_free_space_cache(bg);
> btrfs_put_block_group(bg);
> break;
> }
> +
> btrfs_update_space_info(fs_info, bg->flags, em->len,
> em->len,
> 0, 0, &space_info);
> bg->space_info = space_info;
> @@ -2212,6 +2223,14 @@ int btrfs_read_block_groups(struct
> btrfs_fs_info *info)
> ret = check_chunk_block_group_mappings(info);
> error:
> btrfs_free_path(path);
> + /*
> + * We hit some error reading the extent tree, and have
> rescue=ibadroots
> + * mount option.
> + * Try to fill using dummy block groups so that the user can
> continue
> + * to mount and grab their data.
> + */
> + if (ret && btrfs_test_opt(info, IGNOREBADROOTS))
> + ret = fill_dummy_bgs(info);
> return ret;
> }
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items
2021-07-19 5:43 [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items Qu Wenruo
2021-07-19 5:52 ` Su Yue
@ 2021-07-19 8:19 ` Anand Jain
2021-07-21 17:33 ` David Sterba
2 siblings, 0 replies; 4+ messages in thread
From: Anand Jain @ 2021-07-19 8:19 UTC (permalink / raw)
To: Qu Wenruo, linux-btrfs; +Cc: Zhenyu Wu
On 19/07/2021 13:43, Qu Wenruo wrote:
> When extent tree gets corrupted, normally it's not extent tree root, but
> one toasted tree leaf/node.
>
> In that case, rescue=ibadroots mount option won't help as it can only
> handle the extent tree root corruption.
>
> This patch will enhance the behavior by:
>
> - Allow fill_dummy_bgs() to ignore -EEXIST error
>
> This means we may have some block group items read from disk, but
> then hit some error halfway.
>
> - Fallback to fill_dummy_bgs() if any error gets hit in
> btrfs_read_block_groups()
>
> Of course, this still needs rescue=ibadroots mount option.
>
> With that, rescue=ibadroots can handle extent tree corruption more
> gracefully and allow a better recover chance.
>
> Reported-by: Zhenyu Wu <wuzy001@gmail.com>
> Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
> Changelog:
> v2:
> - Don't try to fill with dummy block groups when we hit ENOMEM
> v3:
> - Remove a dead condition
> The empty fs_info->extent_root case has already been handled.
> v4:
> - Skip to next block group if we hit EEXIST when inserting the block
> group cache
> ---
> fs/btrfs/block-group.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index 5bd76a45037e..758ba856f8c6 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -2105,11 +2105,22 @@ static int fill_dummy_bgs(struct btrfs_fs_info *fs_info)
> bg->used = em->len;
> bg->flags = map->type;
> ret = btrfs_add_block_group_cache(fs_info, bg);
> + /*
> + * We may have some valid block group cache added already, in
> + * that case we skip to next bg.
> + */
> + if (ret == -EEXIST) {
> + ret = 0;
> + btrfs_put_block_group(bg);
> + continue;
Looks good.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Thanks.
> + }
> +
> if (ret) {
> btrfs_remove_free_space_cache(bg);
> btrfs_put_block_group(bg);
> break;
> }
> +
> btrfs_update_space_info(fs_info, bg->flags, em->len, em->len,
> 0, 0, &space_info);
> bg->space_info = space_info;
> @@ -2212,6 +2223,14 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
> ret = check_chunk_block_group_mappings(info);
> error:
> btrfs_free_path(path);
> + /*
> + * We hit some error reading the extent tree, and have rescue=ibadroots
> + * mount option.
> + * Try to fill using dummy block groups so that the user can continue
> + * to mount and grab their data.
> + */
> + if (ret && btrfs_test_opt(info, IGNOREBADROOTS))
> + ret = fill_dummy_bgs(info);
> return ret;
> }
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items
2021-07-19 5:43 [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items Qu Wenruo
2021-07-19 5:52 ` Su Yue
2021-07-19 8:19 ` Anand Jain
@ 2021-07-21 17:33 ` David Sterba
2 siblings, 0 replies; 4+ messages in thread
From: David Sterba @ 2021-07-21 17:33 UTC (permalink / raw)
To: Qu Wenruo; +Cc: linux-btrfs, Zhenyu Wu
On Mon, Jul 19, 2021 at 01:43:04PM +0800, Qu Wenruo wrote:
> When extent tree gets corrupted, normally it's not extent tree root, but
> one toasted tree leaf/node.
>
> In that case, rescue=ibadroots mount option won't help as it can only
> handle the extent tree root corruption.
>
> This patch will enhance the behavior by:
>
> - Allow fill_dummy_bgs() to ignore -EEXIST error
>
> This means we may have some block group items read from disk, but
> then hit some error halfway.
>
> - Fallback to fill_dummy_bgs() if any error gets hit in
> btrfs_read_block_groups()
>
> Of course, this still needs rescue=ibadroots mount option.
>
> With that, rescue=ibadroots can handle extent tree corruption more
> gracefully and allow a better recover chance.
>
> Reported-by: Zhenyu Wu <wuzy001@gmail.com>
> Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
> Changelog:
> v2:
> - Don't try to fill with dummy block groups when we hit ENOMEM
> v3:
> - Remove a dead condition
> The empty fs_info->extent_root case has already been handled.
> v4:
> - Skip to next block group if we hit EEXIST when inserting the block
> group cache
Added to misc-next, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-07-19 5:43 [PATCH v4] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items Qu Wenruo
2021-07-19 5:52 ` Su Yue
2021-07-19 8:19 ` Anand Jain
2021-07-21 17:33 ` David Sterba
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