Josef Bacik
2013-Mar-19 13:43 UTC
[PATCH] Btrfs-progs: make btrfs-image grab the free space cache
A lot of tree log replay bugs are because of strange space cache setups, so make
btrfs-image scrape the free space cache as well so we can better replicate what
a user is seeing if they have a tree log bug or anything related to free space
cache. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
btrfs-image.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 151 insertions(+), 11 deletions(-)
diff --git a/btrfs-image.c b/btrfs-image.c
index ad028de..b39174b 100644
--- a/btrfs-image.c
+++ b/btrfs-image.c
@@ -34,7 +34,7 @@
#include "transaction.h"
#include "utils.h"
#include "version.h"
-
+#include "volumes.h"
#define HEADER_MAGIC 0xbd5c25e27295668bULL
#define MAX_PENDING_SIZE (256 * 1024)
@@ -96,6 +96,7 @@ struct metadump_struct {
int compress_level;
int done;
+ int data;
};
struct mdrestore_struct {
@@ -409,6 +410,60 @@ out:
return err;
}
+static int read_data_extent(struct metadump_struct *md,
+ struct async_work *async)
+{
+ struct btrfs_multi_bio *multi = NULL;
+ struct btrfs_device *device;
+ u64 bytes_left = async->size;
+ u64 logical = async->start;
+ u64 offset = 0;
+ u64 bytenr;
+ u64 read_len;
+ ssize_t done;
+ int fd;
+ int ret;
+
+ while (bytes_left) {
+ read_len = bytes_left;
+ ret = btrfs_map_block(&md->root->fs_info->mapping_tree, READ,
+ logical, &read_len, &multi, 0, NULL);
+ if (ret) {
+ fprintf(stderr, "Couldn''t map data block %d\n", ret);
+ return ret;
+ }
+
+ device = multi->stripes[0].dev;
+
+ if (device->fd == 0) {
+ fprintf(stderr, "Device we need to read from is not "
+ "open\n");
+ free(multi);
+ return -EIO;
+ }
+ fd = device->fd;
+ bytenr = multi->stripes[0].physical;
+ free(multi);
+
+ read_len = min(read_len, bytes_left);
+ done = pread64(fd, async->buffer+offset, read_len, bytenr);
+ if (done < read_len) {
+ if (done < 0)
+ fprintf(stderr, "Error reading extent %d\n",
+ errno);
+ else
+ fprintf(stderr, "Short read\n");
+ return -EIO;
+ }
+
+ bytes_left -= done;
+ offset += done;
+ logical += done;
+ }
+
+ return 0;
+}
+
static int flush_pending(struct metadump_struct *md, int done)
{
struct async_work *async = NULL;
@@ -435,7 +490,17 @@ static int flush_pending(struct metadump_struct *md, int
done)
offset = 0;
start = async->start;
size = async->size;
- while (size > 0) {
+
+ if (md->data) {
+ ret = read_data_extent(md, async);
+ if (ret) {
+ free(async->buffer);
+ free(async);
+ return ret;
+ }
+ }
+
+ while (!md->data && size > 0) {
eb = read_tree_block(md->root, start, blocksize, 0);
if (!eb) {
free(async->buffer);
@@ -480,10 +545,12 @@ static int flush_pending(struct metadump_struct *md, int
done)
return ret;
}
-static int add_metadata(u64 start, u64 size, struct metadump_struct *md)
+static int add_extent(u64 start, u64 size, struct metadump_struct *md,
+ int data)
{
int ret;
- if (md->pending_size + size > MAX_PENDING_SIZE ||
+ if (md->data != data ||
+ md->pending_size + size > MAX_PENDING_SIZE ||
md->pending_start + md->pending_size != start) {
ret = flush_pending(md, 0);
if (ret)
@@ -492,6 +559,7 @@ static int add_metadata(u64 start, u64 size, struct
metadump_struct *md)
}
readahead_tree_block(md->root, start, size, 0);
md->pending_size += size;
+ md->data = data;
return 0;
}
@@ -545,7 +613,7 @@ static int copy_log_blocks(struct btrfs_root *root, struct
extent_buffer *eb,
int i = 0;
int ret;
- ret = add_metadata(btrfs_header_bytenr(eb), root->leafsize, metadump);
+ ret = add_extent(btrfs_header_bytenr(eb), root->leafsize, metadump, 0);
if (ret) {
fprintf(stderr, "Error adding metadata block\n");
return ret;
@@ -610,6 +678,72 @@ static int copy_log_trees(struct btrfs_root *root,
metadump, 1);
}
+static int copy_space_cache(struct btrfs_root *root,
+ struct metadump_struct *metadump,
+ struct btrfs_path *path)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 bytenr, num_bytes;
+ int ret;
+
+ root = root->fs_info->tree_root;
+
+ key.objectid = 0;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ fprintf(stderr, "Error searching for free space inode %d\n",
+ ret);
+ return ret;
+ }
+
+ while (1) {
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ fprintf(stderr, "Error going to next leaf "
+ "%d\n", ret);
+ return ret;
+ }
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.type != BTRFS_EXTENT_DATA_KEY) {
+ path->slots[0]++;
+ continue;
+ }
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) !+ BTRFS_FILE_EXTENT_REG) {
+ path->slots[0]++;
+ continue;
+ }
+
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ ret = add_extent(bytenr, num_bytes, metadump, 1);
+ if (ret) {
+ fprintf(stderr, "Error adding space cache blocks %d\n",
+ ret);
+ btrfs_release_path(root, path);
+ return ret;
+ }
+ path->slots[0]++;
+ }
+
+ return 0;
+}
+
static int create_metadump(const char *input, FILE *out, int num_threads,
int compress_level)
{
@@ -641,7 +775,7 @@ static int create_metadump(const char *input, FILE *out, int
num_threads,
return ret;
}
- ret = add_metadata(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump);
+ ret = add_extent(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump, 0);
if (ret) {
fprintf(stderr, "Error adding metadata %d\n", ret);
err = ret;
@@ -701,8 +835,8 @@ static int create_metadump(const char *input, FILE *out, int
num_threads,
struct btrfs_extent_item);
if (btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_TREE_BLOCK) {
- ret = add_metadata(bytenr, num_bytes,
- &metadump);
+ ret = add_extent(bytenr, num_bytes, &metadump,
+ 0);
if (ret) {
fprintf(stderr, "Error adding block "
"%d\n", ret);
@@ -721,8 +855,8 @@ static int create_metadump(const char *input, FILE *out, int
num_threads,
}
if (ret) {
- ret = add_metadata(bytenr, num_bytes,
- &metadump);
+ ret = add_extent(bytenr, num_bytes, &metadump,
+ 0);
if (ret) {
fprintf(stderr, "Error adding block "
"%d\n", ret);
@@ -740,9 +874,15 @@ static int create_metadump(const char *input, FILE *out,
int num_threads,
bytenr += num_bytes;
}
+ btrfs_release_path(root, path);
+
ret = copy_log_trees(root, &metadump, path);
- if (ret)
+ if (ret) {
err = ret;
+ goto out;
+ }
+
+ ret = copy_space_cache(root, &metadump, path);
out:
ret = flush_pending(&metadump, 1);
if (ret) {
--
1.7.7.6
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