[PATCH] Btrfs-progs: rebuild the crc tree with --init-csum-tree

[PATCH] Btrfs-progs: rebuild the crc tree with --init-csum-tree

[Josef Bacik]

From: Josef Bacik <jbacik@fusionio.com>

We have --init-csum-tree, which just empties the csum tree.  I'm not sure why we
would ever need this, but we definitely need to be able to rebuild the csum tree
in some cases.  This patch adds the ability to completely rebuild the crc tree
by reading all of the data and adding csum entries for them.  This patch doesn't
pay attention to NODATASUM inodes, it'll happily add csums for everything.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
---
 cmds-check.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/cmds-check.c b/cmds-check.c
index 03b0fbd..3141aa4 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6625,6 +6625,98 @@ out:
 	return ret;
 }
 
+static int populate_csum(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *csum_root, char *buf, u64 start,
+			 u64 len)
+{
+	u64 offset = 0;
+	u64 sectorsize;
+	int ret = 0;
+
+	while (offset < len) {
+		sectorsize = csum_root->sectorsize;
+		ret = read_extent_data(csum_root, buf, start + offset,
+				       &sectorsize, 0);
+		if (ret)
+			break;
+		ret = btrfs_csum_file_block(trans, csum_root, start + len,
+					    start + offset, buf, sectorsize);
+		if (ret)
+			break;
+		offset += sectorsize;
+	}
+	return ret;
+}
+
+static int fill_csum_tree(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *csum_root)
+{
+	struct btrfs_root *extent_root = csum_root->fs_info->extent_root;
+	struct btrfs_path *path;
+	struct btrfs_extent_item *ei;
+	struct extent_buffer *leaf;
+	char *buf;
+	struct btrfs_key key;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = 0;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+	if (ret < 0) {
+		btrfs_free_path(path);
+		return ret;
+	}
+
+	buf = malloc(csum_root->sectorsize);
+	if (!buf) {
+		btrfs_free_path(path);
+		return -ENOMEM;
+	}
+
+	while (1) {
+		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+			ret = btrfs_next_leaf(extent_root, path);
+			if (ret < 0)
+				break;
+			if (ret) {
+				ret = 0;
+				break;
+			}
+		}
+		leaf = path->nodes[0];
+
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		if (key.type != BTRFS_EXTENT_ITEM_KEY) {
+			path->slots[0]++;
+			continue;
+		}
+
+		ei = btrfs_item_ptr(leaf, path->slots[0],
+				    struct btrfs_extent_item);
+		if (!(btrfs_extent_flags(leaf, ei) &
+		      BTRFS_EXTENT_FLAG_DATA)) {
+			path->slots[0]++;
+			continue;
+		}
+
+		ret = populate_csum(trans, csum_root, buf, key.objectid,
+				    key.offset);
+		if (ret)
+			break;
+		path->slots[0]++;
+	}
+
+	btrfs_free_path(path);
+	free(buf);
+	return ret;
+}
+
 static struct option long_options[] = {
 	{ "super", 1, NULL, 's' },
 	{ "repair", 0, NULL, 0 },
@@ -6794,6 +6886,12 @@ int cmd_check(int argc, char **argv)
 				ret = -EIO;
 				goto close_out;
 			}
+
+			ret = fill_csum_tree(trans, info->csum_root);
+			if (ret) {
+				fprintf(stderr, "crc refilling failed\n");
+				return -EIO;
+			}
 		}
 		/*
 		 * Ok now we commit and run the normal fsck, which will add
-- 
1.8.3.1

RE: [PATCH] Btrfs-progs: rebuild the crc tree with --init-csum-tree

[Kyle Gates]

Others might be thinking this to so I better ask:
Does this just read the first copy in the case of dup, raid1, etc. and plow on?
I'm
 not sure how you would handle a mismatch due to a hardware error. 
Perhaps read all the copies and create another subvolume containing the 
mismatched copies?

Thanks,
Kyle

> From: jbacik@fb.com
> To: linux-btrfs@vger.kernel.org
> Subject: [PATCH] Btrfs-progs: rebuild the crc tree with --init-csum-tree
> Date: Wed, 1 Oct 2014 10:34:51 -0400
> 
> We have --init-csum-tree, which just empties the csum tree.  I'm not sure why we
> would ever need this, but we definitely need to be able to rebuild the csum tree
> in some cases.  This patch adds the ability to completely rebuild the crc tree
> by reading all of the data and adding csum entries for them.  This patch doesn't
> pay attention to NODATASUM inodes, it'll happily add csums for everything.
> Thanks,
> 
> Signed-off-by: Josef Bacik <jbacik@fb.com>
> ---
>  cmds-check.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 98 insertions(+)
> 
> diff --git a/cmds-check.c b/cmds-check.c
> index 03b0fbd..3141aa4 100644
> --- a/cmds-check.c
> +++ b/cmds-check.c
> @@ -6625,6 +6625,98 @@ out:
>  	return ret;
>  }
>  
> +static int populate_csum(struct btrfs_trans_handle *trans,
> +			 struct btrfs_root *csum_root, char *buf, u64 start,
> +			 u64 len)
> +{
> +	u64 offset = 0;
> +	u64 sectorsize;
> +	int ret = 0;
> +
> +	while (offset < len) {
> +		sectorsize = csum_root->sectorsize;
> +		ret = read_extent_data(csum_root, buf, start + offset,
> +				       &sectorsize, 0);
> +		if (ret)
> +			break;
> +		ret = btrfs_csum_file_block(trans, csum_root, start + len,
> +					    start + offset, buf, sectorsize);
> +		if (ret)
> +			break;
> +		offset += sectorsize;
> +	}
> +	return ret;
> +}
> +
> +static int fill_csum_tree(struct btrfs_trans_handle *trans,
> +			  struct btrfs_root *csum_root)
> +{
> +	struct btrfs_root *extent_root = csum_root->fs_info->extent_root;
> +	struct btrfs_path *path;
> +	struct btrfs_extent_item *ei;
> +	struct extent_buffer *leaf;
> +	char *buf;
> +	struct btrfs_key key;
> +	int ret;
> +
> +	path = btrfs_alloc_path();
> +	if (!path)
> +		return -ENOMEM;
> +
> +	key.objectid = 0;
> +	key.type = BTRFS_EXTENT_ITEM_KEY;
> +	key.offset = 0;
> +
> +	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
> +	if (ret < 0) {
> +		btrfs_free_path(path);
> +		return ret;
> +	}
> +
> +	buf = malloc(csum_root->sectorsize);
> +	if (!buf) {
> +		btrfs_free_path(path);
> +		return -ENOMEM;
> +	}
> +
> +	while (1) {
> +		if (path->slots[0]>= btrfs_header_nritems(path->nodes[0])) {
> +			ret = btrfs_next_leaf(extent_root, path);
> +			if (ret < 0)
> +				break;
> +			if (ret) {
> +				ret = 0;
> +				break;
> +			}
> +		}
> +		leaf = path->nodes[0];
> +
> +		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
> +		if (key.type != BTRFS_EXTENT_ITEM_KEY) {
> +			path->slots[0]++;
> +			continue;
> +		}
> +
> +		ei = btrfs_item_ptr(leaf, path->slots[0],
> +				    struct btrfs_extent_item);
> +		if (!(btrfs_extent_flags(leaf, ei) &
> +		      BTRFS_EXTENT_FLAG_DATA)) {
> +			path->slots[0]++;
> +			continue;
> +		}
> +
> +		ret = populate_csum(trans, csum_root, buf, key.objectid,
> +				    key.offset);
> +		if (ret)
> +			break;
> +		path->slots[0]++;
> +	}
> +
> +	btrfs_free_path(path);
> +	free(buf);
> +	return ret;
> +}
> +
>  static struct option long_options[] = {
>  	{ "super", 1, NULL, 's' },
>  	{ "repair", 0, NULL, 0 },
> @@ -6794,6 +6886,12 @@ int cmd_check(int argc, char **argv)
>  				ret = -EIO;
>  				goto close_out;
>  			}
> +
> +			ret = fill_csum_tree(trans, info->csum_root);
> +			if (ret) {
> +				fprintf(stderr, "crc refilling failed\n");
> +				return -EIO;
> +			}
>  		}
>  		/*
>  		 * Ok now we commit and run the normal fsck, which will add
> -- 
> 1.8.3.1
> 
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
 		 	   		  

[PATCH] Btrfs-progs: rebuild the crc tree with --init-csum-tree

[Josef Bacik]

We have --init-csum-tree, which just empties the csum tree.  I'm not sure why we
would ever need this, but we definitely need to be able to rebuild the csum tree
in some cases.  This patch adds the ability to completely rebuild the crc tree
by reading all of the data and adding csum entries for them.  This patch doesn't
pay attention to NODATASUM inodes, it'll happily add csums for everything.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
---
 cmds-check.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/cmds-check.c b/cmds-check.c
index 03b0fbd..3141aa4 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6625,6 +6625,98 @@ out:
 	return ret;
 }
 
+static int populate_csum(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *csum_root, char *buf, u64 start,
+			 u64 len)
+{
+	u64 offset = 0;
+	u64 sectorsize;
+	int ret = 0;
+
+	while (offset < len) {
+		sectorsize = csum_root->sectorsize;
+		ret = read_extent_data(csum_root, buf, start + offset,
+				       &sectorsize, 0);
+		if (ret)
+			break;
+		ret = btrfs_csum_file_block(trans, csum_root, start + len,
+					    start + offset, buf, sectorsize);
+		if (ret)
+			break;
+		offset += sectorsize;
+	}
+	return ret;
+}
+
+static int fill_csum_tree(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *csum_root)
+{
+	struct btrfs_root *extent_root = csum_root->fs_info->extent_root;
+	struct btrfs_path *path;
+	struct btrfs_extent_item *ei;
+	struct extent_buffer *leaf;
+	char *buf;
+	struct btrfs_key key;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = 0;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+	if (ret < 0) {
+		btrfs_free_path(path);
+		return ret;
+	}
+
+	buf = malloc(csum_root->sectorsize);
+	if (!buf) {
+		btrfs_free_path(path);
+		return -ENOMEM;
+	}
+
+	while (1) {
+		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+			ret = btrfs_next_leaf(extent_root, path);
+			if (ret < 0)
+				break;
+			if (ret) {
+				ret = 0;
+				break;
+			}
+		}
+		leaf = path->nodes[0];
+
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		if (key.type != BTRFS_EXTENT_ITEM_KEY) {
+			path->slots[0]++;
+			continue;
+		}
+
+		ei = btrfs_item_ptr(leaf, path->slots[0],
+				    struct btrfs_extent_item);
+		if (!(btrfs_extent_flags(leaf, ei) &
+		      BTRFS_EXTENT_FLAG_DATA)) {
+			path->slots[0]++;
+			continue;
+		}
+
+		ret = populate_csum(trans, csum_root, buf, key.objectid,
+				    key.offset);
+		if (ret)
+			break;
+		path->slots[0]++;
+	}
+
+	btrfs_free_path(path);
+	free(buf);
+	return ret;
+}
+
 static struct option long_options[] = {
 	{ "super", 1, NULL, 's' },
 	{ "repair", 0, NULL, 0 },
@@ -6794,6 +6886,12 @@ int cmd_check(int argc, char **argv)
 				ret = -EIO;
 				goto close_out;
 			}
+
+			ret = fill_csum_tree(trans, info->csum_root);
+			if (ret) {
+				fprintf(stderr, "crc refilling failed\n");
+				return -EIO;
+			}
 		}
 		/*
 		 * Ok now we commit and run the normal fsck, which will add
-- 
1.8.3.1