hi,all
I''ve been diging into the idea of chunk tree backups. Here is the
predesign, before finishing chunk alloc, the first block in this
chunk will be written in some information, these information will be
useful for chunk tree rebuilding if crash, also the first block will
be moved into fs_info->freed_extents[2], just as the super block.
what we should do is making some changes in these functions:
btrfs_make_block_group
btrfs_read_block_groups
btrfs_remove_block_group
what do you think about it?
There''s something strait with backward compatibility. The mkfs.btrfs
has been made several chunks when creating the fs. It also need to do
the same thing as above. But it will be confusing in some situations
such as old fs mount on new kernel. I think it''s better to add a
incompat flag in super block to mark weather the fs is formaten with
new mkfs.btrfs.
if that''s OK, TODOLIST:
-design the information on chunk''s first block to make it uniqueness
-backward compatibility handle(for example:fix mkfs.btrfs)
Signed-off-by: Wu Bo <wu.bo@cn.fujitsu.com>
---
fs/btrfs/ctree.h | 13 +++-
fs/btrfs/extent-tree.c | 135 +++++++++++++++++++++++++++++++++++++-
fs/btrfs/volumes.c | 168 ++++++++++++++++++++++++++++++++++++++++++++----
fs/btrfs/volumes.h | 25 +++++++
4 files changed, 322 insertions(+), 19 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8b4b9d1..580dd1c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -41,6 +41,7 @@ extern struct kmem_cache *btrfs_transaction_cachep;
extern struct kmem_cache *btrfs_bit_radix_cachep;
extern struct kmem_cache *btrfs_path_cachep;
struct btrfs_ordered_sum;
+struct map_lookup;
#define BTRFS_MAGIC "_BHRfS_M"
@@ -408,6 +409,7 @@ struct btrfs_super_block {
#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1)
#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2)
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3)
+#define BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP (1ULL << 4)
#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
#define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL
@@ -415,7 +417,8 @@ struct btrfs_super_block {
(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \
BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \
- BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO)
+ BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \
+ BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP)
/*
* A leaf is full of items. offset and size tell us where to find
@@ -2172,10 +2175,12 @@ int btrfs_extent_readonly(struct btrfs_root *root, u64
bytenr);
int btrfs_free_block_groups(struct btrfs_fs_info *info);
int btrfs_read_block_groups(struct btrfs_root *root);
int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr);
+
int btrfs_make_block_group(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 bytes_used,
- u64 type, u64 chunk_objectid, u64 chunk_offset,
- u64 size);
+ struct btrfs_root *root, struct map_lookup *map,
+ u64 bytes_used, u64 type, u64 chunk_objectid,
+ u64 chunk_offset, u64 size);
+
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start);
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f1db57d..27ea7d5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -23,6 +23,7 @@
#include <linux/rcupdate.h>
#include <linux/kthread.h>
#include <linux/slab.h>
+#include <linux/buffer_head.h>
#include "compat.h"
#include "hash.h"
#include "ctree.h"
@@ -231,6 +232,113 @@ static int exclude_super_stripes(struct btrfs_root *root,
return 0;
}
+static int exclude_chunk_stripes_header_slow(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ int i;
+ int nr;
+ u64 devid;
+ u64 physical;
+ int stripe_len;
+ u64 stripe_num;
+ u64 *logical;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_chunk *chunk;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int ret;
+
+ ret = 0;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -1;
+
+ root = root->fs_info->chunk_root;
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = cache->key.objectid;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret != 0)
+ goto error;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+
+ if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID ||
+ btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY ||
+ found_key.offset != cache->key.objectid) {
+ ret = -1;
+ goto error;
+ }
+
+ leaf = path->nodes[0];
+ chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk);
+ stripe_num = btrfs_chunk_num_stripes(leaf, chunk);
+
+ i = 0;
+ while (i < stripe_num) {
+ devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+ physical = btrfs_stripe_offset_nr(leaf, chunk, i);
+
+ ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
+ cache->key.objectid, physical, devid, &logical,
+ &nr, &stripe_len);
+ while (nr--) {
+ add_excluded_extent(root, logical[nr], stripe_len);
+
+ /* FIXME.here just use the bytes_super */
+ cache->bytes_super += stripe_len;
+ }
+
+ kfree(logical);
+ i++;
+ }
+
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int exclude_chunk_stripes_header(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache,
+ struct map_lookup *map)
+{
+ int i;
+ int nr;
+ u64 devid;
+ u64 physical;
+ int stripe_len;
+ u64 *logical;
+ int ret;
+
+ if (!map)
+ goto slow;
+
+ i = 0;
+ while (i < map->num_stripes) {
+ devid = map->stripes[i].dev->devid;
+ physical = map->stripes[i].physical;
+ ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
+ cache->key.objectid, physical, devid, &logical,
+ &nr, &stripe_len);
+ while (nr--) {
+ add_excluded_extent(root, logical[nr], stripe_len);
+
+ /* FIXME.here just use the bytes_super */
+ cache->bytes_super += stripe_len;
+ }
+
+ kfree(logical);
+ i++;
+ }
+
+ return 0;
+slow:
+ return exclude_chunk_stripes_header_slow(root, cache);
+}
+
static struct btrfs_caching_control *
get_caching_control(struct btrfs_block_group_cache *cache)
{
@@ -8402,6 +8510,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
struct extent_buffer *leaf;
int need_clear = 0;
u64 cache_gen;
+ u64 feature;
root = info->extent_root;
key.objectid = 0;
@@ -8470,6 +8579,15 @@ int btrfs_read_block_groups(struct btrfs_root *root)
exclude_super_stripes(root, cache);
/*
+ * FIXME, it''s should consider the backward compatibility
+ * also with the user tools for example mkfs.btrfs
+ * Maybe we can judge sb flags to determine whether exclude it
+ */
+ feature = btrfs_super_incompat_flags(&root->fs_info->super_copy);
+ if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP)
+ exclude_chunk_stripes_header(root, cache, NULL);
+
+ /*
* check for two cases, either we are full, and therefore
* don''t need to bother with the caching work since we
won''t
* find any space, or we are empty, and we can just add all
@@ -8533,13 +8651,14 @@ error:
}
int btrfs_make_block_group(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 bytes_used,
- u64 type, u64 chunk_objectid, u64 chunk_offset,
- u64 size)
+ struct btrfs_root *root, struct map_lookup *map,
+ u64 bytes_used, u64 type, u64 chunk_objectid,
+ u64 chunk_offset, u64 size)
{
int ret;
struct btrfs_root *extent_root;
struct btrfs_block_group_cache *cache;
+ u64 feature;
extent_root = root->fs_info->extent_root;
@@ -8577,6 +8696,10 @@ int btrfs_make_block_group(struct btrfs_trans_handle
*trans,
cache->cached = BTRFS_CACHE_FINISHED;
exclude_super_stripes(root, cache);
+ feature = btrfs_super_incompat_flags(&root->fs_info->super_copy);
+ if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP)
+ exclude_chunk_stripes_header(root, cache, map);
+
add_new_free_space(cache, root->fs_info, chunk_offset,
chunk_offset + size);
@@ -8615,6 +8738,12 @@ int btrfs_remove_block_group(struct btrfs_trans_handle
*trans,
struct inode *inode;
int ret;
int factor;
+ u64 feature;
+
+ /* erase the first block which record this chunk info */
+ feature = btrfs_super_incompat_flags(&root->fs_info->super_copy);
+ if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP)
+ erase_chunk_stripes_header(root, group_start);
root = root->fs_info->extent_root;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 94334d9..a9ac2b1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -33,17 +33,6 @@
#include "volumes.h"
#include "async-thread.h"
-struct map_lookup {
- u64 type;
- int io_align;
- int io_width;
- int stripe_len;
- int sector_size;
- int num_stripes;
- int sub_stripes;
- struct btrfs_bio_stripe stripes[];
-};
-
static int init_first_rw_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device);
@@ -2667,7 +2656,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle
*trans,
BUG_ON(ret);
free_extent_map(em);
- ret = btrfs_make_block_group(trans, extent_root, 0, type,
+ ret = btrfs_make_block_group(trans, extent_root, map, 0, type,
BTRFS_FIRST_CHUNK_TREE_OBJECTID,
start, *num_bytes);
BUG_ON(ret);
@@ -2761,6 +2750,151 @@ static int __finish_chunk_alloc(struct
btrfs_trans_handle *trans,
return 0;
}
+static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
+{
+ char b[BDEVNAME_SIZE];
+
+ if (uptodate) {
+ set_buffer_uptodate(bh);
+ } else {
+ if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ printk(KERN_WARNING "lost page write due to I/O error on %s\n",
+ bdevname(bh->b_bdev, b));
+ }
+ clear_buffer_uptodate(bh);
+ }
+ unlock_buffer(bh);
+ put_bh(bh);
+}
+
+static int mark_chunk_stripes_header(struct btrfs_root *root,
+ struct map_lookup *map, u64 chunk_offset,
+ u64 chunk_size, u64 stripe_size, u64 flag)
+{
+ struct buffer_head *bh;
+ struct btrfs_device *device = NULL;
+ struct btrfs_stripe_header header;
+ u64 bytenr;
+ u32 sectorsize;
+ int index;
+ int ret;
+
+ ret = 0;
+ index = 0;
+ while (index < map->num_stripes) {
+ device = map->stripes[index].dev;
+ bytenr = map->stripes[index].physical;
+ sectorsize = root->sectorsize;
+ do_div(bytenr, sectorsize);
+ bh = __getblk(device->bdev, bytenr, sectorsize);
+ if (!bh)
+ return -1;
+
+ memset(&header, 0, sizeof(header));
+ header.magic = cpu_to_le64(BTRFS_STRIPE_HEADER_MAGIC);
+ header.chunk_offset = cpu_to_le64(chunk_offset);
+ header.chunk_size = cpu_to_le64(chunk_size);
+ header.stripe_size = cpu_to_le64(stripe_size);
+ header.stripe_index = cpu_to_le32(index);
+ header.flag = cpu_to_le64(flag);
+ memcpy(header.fsid, root->fs_info->fsid, BTRFS_FSID_SIZE);
+
+ memset(bh->b_data, 0, sectorsize);
+ memcpy(bh->b_data, &header, sizeof(header));
+
+ get_bh(bh);
+ set_buffer_uptodate(bh);
+ lock_buffer(bh);
+ bh->b_end_io = btrfs_end_buffer_write_sync;
+
+ ret = submit_bh(WRITE_SYNC, bh);
+ wait_on_buffer(bh);
+ brelse(bh);
+
+ index++;
+ }
+ return ret;
+}
+
+int erase_chunk_stripes_header(struct btrfs_root *root,
+ u64 chunk_offset)
+{
+ int i;
+ int ret;
+ u64 devid;
+ u64 physical;
+ u32 sectorsize;
+ u64 stripe_num;
+ u8 uuid[BTRFS_UUID_SIZE];
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_chunk *chunk;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ struct btrfs_device *device;
+ struct buffer_head *bh;
+
+ ret = 0;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -1;
+
+ root = root->fs_info->chunk_root;
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = chunk_offset;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret != 0) {
+ ret = -1;
+ goto error;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+
+ if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID ||
+ btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY ||
+ found_key.offset != chunk_offset) {
+ ret = -1;
+ goto error;
+ }
+
+ leaf = path->nodes[0];
+ chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk);
+ stripe_num = btrfs_chunk_num_stripes(leaf, chunk);
+ i = 0;
+ while (i < stripe_num) {
+ devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+ physical = btrfs_stripe_offset_nr(leaf, chunk, i);
+ read_extent_buffer(leaf, uuid, (unsigned long)
+ btrfs_stripe_dev_uuid_nr(chunk, i),
+ BTRFS_UUID_SIZE);
+ device = btrfs_find_device(root, devid, uuid, NULL);
+
+ sectorsize = root->sectorsize;
+ do_div(physical, sectorsize);
+ bh = __getblk(device->bdev, physical, sectorsize);
+ if (!bh) {
+ i++;
+ continue;
+ }
+ memset(bh->b_data, 0, sectorsize);
+ get_bh(bh);
+ set_buffer_uptodate(bh);
+ lock_buffer(bh);
+ bh->b_end_io = btrfs_end_buffer_write_sync;
+
+ submit_bh(WRITE_SYNC, bh);
+ wait_on_buffer(bh);
+ brelse(bh);
+ i++;
+ }
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
/*
* Chunk allocation falls into two parts. The first part does works
* that make the new allocated chunk useable, but not do any operation
@@ -2777,6 +2911,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct map_lookup *map;
struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
int ret;
+ u64 feature;
ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
&chunk_offset);
@@ -2791,6 +2926,15 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
chunk_size, stripe_size);
BUG_ON(ret);
+
+ feature =
btrfs_super_incompat_flags(&extent_root->fs_info->super_copy);
+ if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) {
+ ret = mark_chunk_stripes_header(extent_root, map, chunk_offset,
+ chunk_size, stripe_size, type);
+ if (ret)
+ return ret;
+ }
+
return 0;
}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7af6144..7166a3b 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -146,6 +146,31 @@ struct btrfs_device_info {
u64 max_avail;
};
+struct map_lookup {
+ u64 type;
+ int io_align;
+ int io_width;
+ int stripe_len;
+ int sector_size;
+ int num_stripes;
+ int sub_stripes;
+ struct btrfs_bio_stripe stripes[];
+};
+
+#define BTRFS_STRIPE_HEADER_MAGIC 111111
+
+struct btrfs_stripe_header {
+ __le64 magic;
+ __le64 chunk_offset;
+ __le64 chunk_size;
+ __le64 stripe_size;
+ __le32 stripe_index;
+ __le64 flag;
+ u8 fsid[BTRFS_FSID_SIZE];
+} __attribute__ ((__packed__));
+
+int erase_chunk_stripes_header(struct btrfs_root *root, u64 chunk_offset);
+
/* Used to sort the devices by max_avail(descending sort) */
int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);
--
1.7.3.1
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If no one has comments on this, I''ll work on finishing it. Thanks Wubo On 04/07/2011 03:57 PM, WuBo wrote:> hi,all > > I''ve been diging into the idea of chunk tree backups. Here is the > predesign, before finishing chunk alloc, the first block in this > chunk will be written in some information, these information will be > useful for chunk tree rebuilding if crash, also the first block will > be moved into fs_info->freed_extents[2], just as the super block. > what we should do is making some changes in these functions: > btrfs_make_block_group > btrfs_read_block_groups > btrfs_remove_block_group > what do you think about it? > > There''s something strait with backward compatibility. The mkfs.btrfs > has been made several chunks when creating the fs. It also need to do > the same thing as above. But it will be confusing in some situations > such as old fs mount on new kernel. I think it''s better to add a > incompat flag in super block to mark weather the fs is formaten with > new mkfs.btrfs. > > if that''s OK, TODOLIST: > -design the information on chunk''s first block to make it uniqueness > -backward compatibility handle(for example:fix mkfs.btrfs) > > Signed-off-by: Wu Bo <wu.bo@cn.fujitsu.com> > --- > fs/btrfs/ctree.h | 13 +++- > fs/btrfs/extent-tree.c | 135 +++++++++++++++++++++++++++++++++++++- > fs/btrfs/volumes.c | 168 ++++++++++++++++++++++++++++++++++++++++++++---- > fs/btrfs/volumes.h | 25 +++++++ > 4 files changed, 322 insertions(+), 19 deletions(-) > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index 8b4b9d1..580dd1c 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -41,6 +41,7 @@ extern struct kmem_cache *btrfs_transaction_cachep; > extern struct kmem_cache *btrfs_bit_radix_cachep; > extern struct kmem_cache *btrfs_path_cachep; > struct btrfs_ordered_sum; > +struct map_lookup; > > #define BTRFS_MAGIC "_BHRfS_M" > > @@ -408,6 +409,7 @@ struct btrfs_super_block { > #define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1) > #define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2) > #define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3) > +#define BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP (1ULL << 4) > > #define BTRFS_FEATURE_COMPAT_SUPP 0ULL > #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL > @@ -415,7 +417,8 @@ struct btrfs_super_block { > (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ > BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \ > BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \ > - BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO) > + BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \ > + BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > > /* > * A leaf is full of items. offset and size tell us where to find > @@ -2172,10 +2175,12 @@ int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr); > int btrfs_free_block_groups(struct btrfs_fs_info *info); > int btrfs_read_block_groups(struct btrfs_root *root); > int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr); > + > int btrfs_make_block_group(struct btrfs_trans_handle *trans, > - struct btrfs_root *root, u64 bytes_used, > - u64 type, u64 chunk_objectid, u64 chunk_offset, > - u64 size); > + struct btrfs_root *root, struct map_lookup *map, > + u64 bytes_used, u64 type, u64 chunk_objectid, > + u64 chunk_offset, u64 size); > + > int btrfs_remove_block_group(struct btrfs_trans_handle *trans, > struct btrfs_root *root, u64 group_start); > u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags); > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index f1db57d..27ea7d5 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -23,6 +23,7 @@ > #include <linux/rcupdate.h> > #include <linux/kthread.h> > #include <linux/slab.h> > +#include <linux/buffer_head.h> > #include "compat.h" > #include "hash.h" > #include "ctree.h" > @@ -231,6 +232,113 @@ static int exclude_super_stripes(struct btrfs_root *root, > return 0; > } > > +static int exclude_chunk_stripes_header_slow(struct btrfs_root *root, > + struct btrfs_block_group_cache *cache) > +{ > + int i; > + int nr; > + u64 devid; > + u64 physical; > + int stripe_len; > + u64 stripe_num; > + u64 *logical; > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_chunk *chunk; > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + int ret; > + > + ret = 0; > + path = btrfs_alloc_path(); > + if (!path) > + return -1; > + > + root = root->fs_info->chunk_root; > + > + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; > + key.offset = cache->key.objectid; > + key.type = BTRFS_CHUNK_ITEM_KEY; > + > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > + if (ret != 0) > + goto error; > + > + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); > + > + if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID || > + btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY || > + found_key.offset != cache->key.objectid) { > + ret = -1; > + goto error; > + } > + > + leaf = path->nodes[0]; > + chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk); > + stripe_num = btrfs_chunk_num_stripes(leaf, chunk); > + > + i = 0; > + while (i < stripe_num) { > + devid = btrfs_stripe_devid_nr(leaf, chunk, i); > + physical = btrfs_stripe_offset_nr(leaf, chunk, i); > + > + ret = btrfs_rmap_block(&root->fs_info->mapping_tree, > + cache->key.objectid, physical, devid, &logical, > + &nr, &stripe_len); > + while (nr--) { > + add_excluded_extent(root, logical[nr], stripe_len); > + > + /* FIXME.here just use the bytes_super */ > + cache->bytes_super += stripe_len; > + } > + > + kfree(logical); > + i++; > + } > + > +error: > + btrfs_free_path(path); > + return ret; > +} > + > +static int exclude_chunk_stripes_header(struct btrfs_root *root, > + struct btrfs_block_group_cache *cache, > + struct map_lookup *map) > +{ > + int i; > + int nr; > + u64 devid; > + u64 physical; > + int stripe_len; > + u64 *logical; > + int ret; > + > + if (!map) > + goto slow; > + > + i = 0; > + while (i < map->num_stripes) { > + devid = map->stripes[i].dev->devid; > + physical = map->stripes[i].physical; > + ret = btrfs_rmap_block(&root->fs_info->mapping_tree, > + cache->key.objectid, physical, devid, &logical, > + &nr, &stripe_len); > + while (nr--) { > + add_excluded_extent(root, logical[nr], stripe_len); > + > + /* FIXME.here just use the bytes_super */ > + cache->bytes_super += stripe_len; > + } > + > + kfree(logical); > + i++; > + } > + > + return 0; > +slow: > + return exclude_chunk_stripes_header_slow(root, cache); > +} > + > static struct btrfs_caching_control * > get_caching_control(struct btrfs_block_group_cache *cache) > { > @@ -8402,6 +8510,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) > struct extent_buffer *leaf; > int need_clear = 0; > u64 cache_gen; > + u64 feature; > > root = info->extent_root; > key.objectid = 0; > @@ -8470,6 +8579,15 @@ int btrfs_read_block_groups(struct btrfs_root *root) > exclude_super_stripes(root, cache); > > /* > + * FIXME, it''s should consider the backward compatibility > + * also with the user tools for example mkfs.btrfs > + * Maybe we can judge sb flags to determine whether exclude it > + */ > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + exclude_chunk_stripes_header(root, cache, NULL); > + > + /* > * check for two cases, either we are full, and therefore > * don''t need to bother with the caching work since we won''t > * find any space, or we are empty, and we can just add all > @@ -8533,13 +8651,14 @@ error: > } > > int btrfs_make_block_group(struct btrfs_trans_handle *trans, > - struct btrfs_root *root, u64 bytes_used, > - u64 type, u64 chunk_objectid, u64 chunk_offset, > - u64 size) > + struct btrfs_root *root, struct map_lookup *map, > + u64 bytes_used, u64 type, u64 chunk_objectid, > + u64 chunk_offset, u64 size) > { > int ret; > struct btrfs_root *extent_root; > struct btrfs_block_group_cache *cache; > + u64 feature; > > extent_root = root->fs_info->extent_root; > > @@ -8577,6 +8696,10 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, > cache->cached = BTRFS_CACHE_FINISHED; > exclude_super_stripes(root, cache); > > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + exclude_chunk_stripes_header(root, cache, map); > + > add_new_free_space(cache, root->fs_info, chunk_offset, > chunk_offset + size); > > @@ -8615,6 +8738,12 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans, > struct inode *inode; > int ret; > int factor; > + u64 feature; > + > + /* erase the first block which record this chunk info */ > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + erase_chunk_stripes_header(root, group_start); > > root = root->fs_info->extent_root; > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 94334d9..a9ac2b1 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -33,17 +33,6 @@ > #include "volumes.h" > #include "async-thread.h" > > -struct map_lookup { > - u64 type; > - int io_align; > - int io_width; > - int stripe_len; > - int sector_size; > - int num_stripes; > - int sub_stripes; > - struct btrfs_bio_stripe stripes[]; > -}; > - > static int init_first_rw_device(struct btrfs_trans_handle *trans, > struct btrfs_root *root, > struct btrfs_device *device); > @@ -2667,7 +2656,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > BUG_ON(ret); > free_extent_map(em); > > - ret = btrfs_make_block_group(trans, extent_root, 0, type, > + ret = btrfs_make_block_group(trans, extent_root, map, 0, type, > BTRFS_FIRST_CHUNK_TREE_OBJECTID, > start, *num_bytes); > BUG_ON(ret); > @@ -2761,6 +2750,151 @@ static int __finish_chunk_alloc(struct btrfs_trans_handle *trans, > return 0; > } > > +static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) > +{ > + char b[BDEVNAME_SIZE]; > + > + if (uptodate) { > + set_buffer_uptodate(bh); > + } else { > + if (!buffer_eopnotsupp(bh) && printk_ratelimit()) { > + printk(KERN_WARNING "lost page write due to I/O error on %s\n", > + bdevname(bh->b_bdev, b)); > + } > + clear_buffer_uptodate(bh); > + } > + unlock_buffer(bh); > + put_bh(bh); > +} > + > +static int mark_chunk_stripes_header(struct btrfs_root *root, > + struct map_lookup *map, u64 chunk_offset, > + u64 chunk_size, u64 stripe_size, u64 flag) > +{ > + struct buffer_head *bh; > + struct btrfs_device *device = NULL; > + struct btrfs_stripe_header header; > + u64 bytenr; > + u32 sectorsize; > + int index; > + int ret; > + > + ret = 0; > + index = 0; > + while (index < map->num_stripes) { > + device = map->stripes[index].dev; > + bytenr = map->stripes[index].physical; > + sectorsize = root->sectorsize; > + do_div(bytenr, sectorsize); > + bh = __getblk(device->bdev, bytenr, sectorsize); > + if (!bh) > + return -1; > + > + memset(&header, 0, sizeof(header)); > + header.magic = cpu_to_le64(BTRFS_STRIPE_HEADER_MAGIC); > + header.chunk_offset = cpu_to_le64(chunk_offset); > + header.chunk_size = cpu_to_le64(chunk_size); > + header.stripe_size = cpu_to_le64(stripe_size); > + header.stripe_index = cpu_to_le32(index); > + header.flag = cpu_to_le64(flag); > + memcpy(header.fsid, root->fs_info->fsid, BTRFS_FSID_SIZE); > + > + memset(bh->b_data, 0, sectorsize); > + memcpy(bh->b_data, &header, sizeof(header)); > + > + get_bh(bh); > + set_buffer_uptodate(bh); > + lock_buffer(bh); > + bh->b_end_io = btrfs_end_buffer_write_sync; > + > + ret = submit_bh(WRITE_SYNC, bh); > + wait_on_buffer(bh); > + brelse(bh); > + > + index++; > + } > + return ret; > +} > + > +int erase_chunk_stripes_header(struct btrfs_root *root, > + u64 chunk_offset) > +{ > + int i; > + int ret; > + u64 devid; > + u64 physical; > + u32 sectorsize; > + u64 stripe_num; > + u8 uuid[BTRFS_UUID_SIZE]; > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_chunk *chunk; > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + struct btrfs_device *device; > + struct buffer_head *bh; > + > + ret = 0; > + path = btrfs_alloc_path(); > + if (!path) > + return -1; > + > + root = root->fs_info->chunk_root; > + > + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; > + key.offset = chunk_offset; > + key.type = BTRFS_CHUNK_ITEM_KEY; > + > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > + if (ret != 0) { > + ret = -1; > + goto error; > + } > + > + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); > + > + if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID || > + btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY || > + found_key.offset != chunk_offset) { > + ret = -1; > + goto error; > + } > + > + leaf = path->nodes[0]; > + chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk); > + stripe_num = btrfs_chunk_num_stripes(leaf, chunk); > + i = 0; > + while (i < stripe_num) { > + devid = btrfs_stripe_devid_nr(leaf, chunk, i); > + physical = btrfs_stripe_offset_nr(leaf, chunk, i); > + read_extent_buffer(leaf, uuid, (unsigned long) > + btrfs_stripe_dev_uuid_nr(chunk, i), > + BTRFS_UUID_SIZE); > + device = btrfs_find_device(root, devid, uuid, NULL); > + > + sectorsize = root->sectorsize; > + do_div(physical, sectorsize); > + bh = __getblk(device->bdev, physical, sectorsize); > + if (!bh) { > + i++; > + continue; > + } > + memset(bh->b_data, 0, sectorsize); > + get_bh(bh); > + set_buffer_uptodate(bh); > + lock_buffer(bh); > + bh->b_end_io = btrfs_end_buffer_write_sync; > + > + submit_bh(WRITE_SYNC, bh); > + wait_on_buffer(bh); > + brelse(bh); > + i++; > + } > +error: > + btrfs_free_path(path); > + return ret; > +} > + > /* > * Chunk allocation falls into two parts. The first part does works > * that make the new allocated chunk useable, but not do any operation > @@ -2777,6 +2911,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > struct map_lookup *map; > struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; > int ret; > + u64 feature; > > ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, > &chunk_offset); > @@ -2791,6 +2926,15 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, > chunk_size, stripe_size); > BUG_ON(ret); > + > + feature = btrfs_super_incompat_flags(&extent_root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) { > + ret = mark_chunk_stripes_header(extent_root, map, chunk_offset, > + chunk_size, stripe_size, type); > + if (ret) > + return ret; > + } > + > return 0; > } > > diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h > index 7af6144..7166a3b 100644 > --- a/fs/btrfs/volumes.h > +++ b/fs/btrfs/volumes.h > @@ -146,6 +146,31 @@ struct btrfs_device_info { > u64 max_avail; > }; > > +struct map_lookup { > + u64 type; > + int io_align; > + int io_width; > + int stripe_len; > + int sector_size; > + int num_stripes; > + int sub_stripes; > + struct btrfs_bio_stripe stripes[]; > +}; > + > +#define BTRFS_STRIPE_HEADER_MAGIC 111111 > + > +struct btrfs_stripe_header { > + __le64 magic; > + __le64 chunk_offset; > + __le64 chunk_size; > + __le64 stripe_size; > + __le32 stripe_index; > + __le64 flag; > + u8 fsid[BTRFS_FSID_SIZE]; > +} __attribute__ ((__packed__)); > + > +int erase_chunk_stripes_header(struct btrfs_root *root, u64 chunk_offset); > + > /* Used to sort the devices by max_avail(descending sort) */ > int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2); >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On Thu, Apr 07, 2011 at 03:57:50PM +0800, WuBo wrote:> hi,all > > I''ve been diging into the idea of chunk tree backups. Here is the > predesign, before finishing chunk alloc, the first block in this > chunk will be written in some information, these information will be > useful for chunk tree rebuilding if crash, also the first block will > be moved into fs_info->freed_extents[2], just as the super block. > what we should do is making some changes in these functions: > btrfs_make_block_group > btrfs_read_block_groups > btrfs_remove_block_group > what do you think about it?while I don''t quite understand what you are implementing, I can give you a few comments on the code itself. It would be good if you describe your design in more details. I think if you are touching crash recoverya, some description of how the chunk copies are used etc, and possibly if fsck can benefit from it.> There''s something strait with backward compatibility. The mkfs.btrfs > has been made several chunks when creating the fs. It also need to do > the same thing as above. But it will be confusing in some situations > such as old fs mount on new kernel. I think it''s better to add a > incompat flag in super block to mark weather the fs is formaten with > new mkfs.btrfs. > > if that''s OK, TODOLIST: > -design the information on chunk''s first block to make it uniqueness(I hope this covers the questions stated above)> -backward compatibility handle(for example:fix mkfs.btrfs) > > Signed-off-by: Wu Bo <wu.bo@cn.fujitsu.com> > --- > fs/btrfs/ctree.h | 13 +++- > fs/btrfs/extent-tree.c | 135 +++++++++++++++++++++++++++++++++++++- > fs/btrfs/volumes.c | 168 ++++++++++++++++++++++++++++++++++++++++++++---- > fs/btrfs/volumes.h | 25 +++++++ > 4 files changed, 322 insertions(+), 19 deletions(-) > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index 8b4b9d1..580dd1c 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -41,6 +41,7 @@ extern struct kmem_cache *btrfs_transaction_cachep; > extern struct kmem_cache *btrfs_bit_radix_cachep; > extern struct kmem_cache *btrfs_path_cachep; > struct btrfs_ordered_sum; > +struct map_lookup; > > #define BTRFS_MAGIC "_BHRfS_M" > > @@ -408,6 +409,7 @@ struct btrfs_super_block { > #define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1) > #define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2) > #define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3) > +#define BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP (1ULL << 4) > > #define BTRFS_FEATURE_COMPAT_SUPP 0ULL > #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL > @@ -415,7 +417,8 @@ struct btrfs_super_block { > (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ > BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \ > BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \ > - BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO) > + BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \ > + BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > > /* > * A leaf is full of items. offset and size tell us where to find > @@ -2172,10 +2175,12 @@ int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr); > int btrfs_free_block_groups(struct btrfs_fs_info *info); > int btrfs_read_block_groups(struct btrfs_root *root); > int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr); > + > int btrfs_make_block_group(struct btrfs_trans_handle *trans, > - struct btrfs_root *root, u64 bytes_used, > - u64 type, u64 chunk_objectid, u64 chunk_offset, > - u64 size); > + struct btrfs_root *root, struct map_lookup *map, > + u64 bytes_used, u64 type, u64 chunk_objectid, > + u64 chunk_offset, u64 size); > + > int btrfs_remove_block_group(struct btrfs_trans_handle *trans, > struct btrfs_root *root, u64 group_start); > u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags); > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index f1db57d..27ea7d5 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -23,6 +23,7 @@ > #include <linux/rcupdate.h> > #include <linux/kthread.h> > #include <linux/slab.h> > +#include <linux/buffer_head.h> > #include "compat.h" > #include "hash.h" > #include "ctree.h" > @@ -231,6 +232,113 @@ static int exclude_super_stripes(struct btrfs_root *root, > return 0; > } > > +static int exclude_chunk_stripes_header_slow(struct btrfs_root *root, > + struct btrfs_block_group_cache *cache) > +{ > + int i; > + int nr; > + u64 devid; > + u64 physical; > + int stripe_len; > + u64 stripe_num; > + u64 *logical; > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_chunk *chunk; > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + int ret; > + > + ret = 0; > + path = btrfs_alloc_path(); > + if (!path) > + return -1;return -ENOMEM;> + > + root = root->fs_info->chunk_root; > + > + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; > + key.offset = cache->key.objectid; > + key.type = BTRFS_CHUNK_ITEM_KEY; > + > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > + if (ret != 0) > + goto error; > + > + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); > + > + if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID || > + btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY || > + found_key.offset != cache->key.objectid) { > + ret = -1;-1 does not seem a good return code> + goto error; > + } > + > + leaf = path->nodes[0]; > + chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk); > + stripe_num = btrfs_chunk_num_stripes(leaf, chunk); > + > + i = 0; > + while (i < stripe_num) {for (i = 0; i < stripe_num; i++) {> + devid = btrfs_stripe_devid_nr(leaf, chunk, i); > + physical = btrfs_stripe_offset_nr(leaf, chunk, i); > + > + ret = btrfs_rmap_block(&root->fs_info->mapping_tree, > + cache->key.objectid, physical, devid, &logical, > + &nr, &stripe_len);though btrfs_rmap_block() does return only 0 by now, it can potentially return -ENOMEM (a BUG_ON is there right now), so add a check please> + while (nr--) { > + add_excluded_extent(root, logical[nr], stripe_len); > + > + /* FIXME.here just use the bytes_super */ > + cache->bytes_super += stripe_len; > + } > + > + kfree(logical); > + i++; > + } > + > +error: > + btrfs_free_path(path); > + return ret; > +} > + > +static int exclude_chunk_stripes_header(struct btrfs_root *root, > + struct btrfs_block_group_cache *cache, > + struct map_lookup *map) > +{ > + int i; > + int nr; > + u64 devid; > + u64 physical; > + int stripe_len; > + u64 *logical; > + int ret; > + > + if (!map) > + goto slow;return exclude_chunk_stripes_header_slow(root, cache); no need to scroll down to look what it means ''slow''> + > + i = 0; > + while (i < map->num_stripes) { > + devid = map->stripes[i].dev->devid; > + physical = map->stripes[i].physical; > + ret = btrfs_rmap_block(&root->fs_info->mapping_tree, > + cache->key.objectid, physical, devid, &logical, > + &nr, &stripe_len);return value check> + while (nr--) { > + add_excluded_extent(root, logical[nr], stripe_len); > + > + /* FIXME.here just use the bytes_super */ > + cache->bytes_super += stripe_len; > + } > + > + kfree(logical); > + i++; > + } > + > + return 0; > +slow: > + return exclude_chunk_stripes_header_slow(root, cache); > +} > + > static struct btrfs_caching_control * > get_caching_control(struct btrfs_block_group_cache *cache) > { > @@ -8402,6 +8510,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) > struct extent_buffer *leaf; > int need_clear = 0; > u64 cache_gen; > + u64 feature; > > root = info->extent_root; > key.objectid = 0; > @@ -8470,6 +8579,15 @@ int btrfs_read_block_groups(struct btrfs_root *root) > exclude_super_stripes(root, cache); > > /* > + * FIXME, it''s should consider the backward compatibility > + * also with the user tools for example mkfs.btrfs > + * Maybe we can judge sb flags to determine whether exclude it > + */ > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + exclude_chunk_stripes_header(root, cache, NULL); > + > + /* > * check for two cases, either we are full, and therefore > * don''t need to bother with the caching work since we won''t > * find any space, or we are empty, and we can just add all > @@ -8533,13 +8651,14 @@ error: > } > > int btrfs_make_block_group(struct btrfs_trans_handle *trans, > - struct btrfs_root *root, u64 bytes_used, > - u64 type, u64 chunk_objectid, u64 chunk_offset, > - u64 size) > + struct btrfs_root *root, struct map_lookup *map, > + u64 bytes_used, u64 type, u64 chunk_objectid, > + u64 chunk_offset, u64 size) > { > int ret; > struct btrfs_root *extent_root; > struct btrfs_block_group_cache *cache; > + u64 feature; > > extent_root = root->fs_info->extent_root; > > @@ -8577,6 +8696,10 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, > cache->cached = BTRFS_CACHE_FINISHED; > exclude_super_stripes(root, cache); > > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + exclude_chunk_stripes_header(root, cache, map); > + > add_new_free_space(cache, root->fs_info, chunk_offset, > chunk_offset + size); > > @@ -8615,6 +8738,12 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans, > struct inode *inode; > int ret; > int factor; > + u64 feature; > + > + /* erase the first block which record this chunk info */ > + feature = btrfs_super_incompat_flags(&root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) > + erase_chunk_stripes_header(root, group_start); > > root = root->fs_info->extent_root; > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 94334d9..a9ac2b1 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -33,17 +33,6 @@ > #include "volumes.h" > #include "async-thread.h" > > -struct map_lookup { > - u64 type; > - int io_align; > - int io_width; > - int stripe_len; > - int sector_size; > - int num_stripes; > - int sub_stripes; > - struct btrfs_bio_stripe stripes[]; > -};already moved to .h> - > static int init_first_rw_device(struct btrfs_trans_handle *trans, > struct btrfs_root *root, > struct btrfs_device *device); > @@ -2667,7 +2656,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > BUG_ON(ret); > free_extent_map(em); > > - ret = btrfs_make_block_group(trans, extent_root, 0, type, > + ret = btrfs_make_block_group(trans, extent_root, map, 0, type, > BTRFS_FIRST_CHUNK_TREE_OBJECTID, > start, *num_bytes); > BUG_ON(ret); > @@ -2761,6 +2750,151 @@ static int __finish_chunk_alloc(struct btrfs_trans_handle *trans, > return 0; > } > > +static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) > +{ > + char b[BDEVNAME_SIZE]; > + > + if (uptodate) { > + set_buffer_uptodate(bh); > + } else { > + if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {^^^^^^^^^^^^^^^^ should not be used in new code, it consults global ratelimit shared with any printk_ratelimit caller. use printk_ratelimited (which maintains own ratelimit counter)> + printk(KERN_WARNING "lost page write due to I/O error on %s\n", > + bdevname(bh->b_bdev, b)); > + } > + clear_buffer_uptodate(bh); > + } > + unlock_buffer(bh); > + put_bh(bh); > +} > + > +static int mark_chunk_stripes_header(struct btrfs_root *root, > + struct map_lookup *map, u64 chunk_offset, > + u64 chunk_size, u64 stripe_size, u64 flag) > +{ > + struct buffer_head *bh; > + struct btrfs_device *device = NULL; > + struct btrfs_stripe_header header; > + u64 bytenr; > + u32 sectorsize; > + int index; > + int ret; > + > + ret = 0; > + index = 0; > + while (index < map->num_stripes) {for (index = 0; index < map->num_stripes; index++) {> + device = map->stripes[index].dev; > + bytenr = map->stripes[index].physical; > + sectorsize = root->sectorsize; > + do_div(bytenr, sectorsize); > + bh = __getblk(device->bdev, bytenr, sectorsize); > + if (!bh) > + return -1; > + > + memset(&header, 0, sizeof(header)); > + header.magic = cpu_to_le64(BTRFS_STRIPE_HEADER_MAGIC); > + header.chunk_offset = cpu_to_le64(chunk_offset); > + header.chunk_size = cpu_to_le64(chunk_size); > + header.stripe_size = cpu_to_le64(stripe_size); > + header.stripe_index = cpu_to_le32(index); > + header.flag = cpu_to_le64(flag); > + memcpy(header.fsid, root->fs_info->fsid, BTRFS_FSID_SIZE); > + > + memset(bh->b_data, 0, sectorsize); > + memcpy(bh->b_data, &header, sizeof(header)); > + > + get_bh(bh); > + set_buffer_uptodate(bh); > + lock_buffer(bh); > + bh->b_end_io = btrfs_end_buffer_write_sync; > + > + ret = submit_bh(WRITE_SYNC, bh); > + wait_on_buffer(bh); > + brelse(bh); > + > + index++; > + } > + return ret; > +} > + > +int erase_chunk_stripes_header(struct btrfs_root *root, > + u64 chunk_offset) > +{ > + int i; > + int ret; > + u64 devid; > + u64 physical; > + u32 sectorsize; > + u64 stripe_num; > + u8 uuid[BTRFS_UUID_SIZE]; > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_chunk *chunk; > + struct btrfs_key found_key; > + struct extent_buffer *leaf; > + struct btrfs_device *device; > + struct buffer_head *bh; > + > + ret = 0; > + path = btrfs_alloc_path(); > + if (!path) > + return -1;return -ENOMEM;> + > + root = root->fs_info->chunk_root; > + > + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; > + key.offset = chunk_offset; > + key.type = BTRFS_CHUNK_ITEM_KEY; > + > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > + if (ret != 0) { > + ret = -1;something else than -1> + goto error; > + } > + > + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); > + > + if (found_key.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID || > + btrfs_key_type(&found_key) != BTRFS_CHUNK_ITEM_KEY || > + found_key.offset != chunk_offset) { > + ret = -1;something else than -1> + goto error; > + } > + > + leaf = path->nodes[0]; > + chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk); > + stripe_num = btrfs_chunk_num_stripes(leaf, chunk); > + i = 0; > + while (i < stripe_num) {for (...)> + devid = btrfs_stripe_devid_nr(leaf, chunk, i); > + physical = btrfs_stripe_offset_nr(leaf, chunk, i); > + read_extent_buffer(leaf, uuid, (unsigned long) > + btrfs_stripe_dev_uuid_nr(chunk, i), > + BTRFS_UUID_SIZE); > + device = btrfs_find_device(root, devid, uuid, NULL); > + > + sectorsize = root->sectorsize; > + do_div(physical, sectorsize); > + bh = __getblk(device->bdev, physical, sectorsize); > + if (!bh) { > + i++; > + continue; > + } > + memset(bh->b_data, 0, sectorsize); > + get_bh(bh); > + set_buffer_uptodate(bh); > + lock_buffer(bh); > + bh->b_end_io = btrfs_end_buffer_write_sync; > + > + submit_bh(WRITE_SYNC, bh); > + wait_on_buffer(bh); > + brelse(bh); > + i++; > + } > +error: > + btrfs_free_path(path); > + return ret; > +} > + > /* > * Chunk allocation falls into two parts. The first part does works > * that make the new allocated chunk useable, but not do any operation > @@ -2777,6 +2911,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > struct map_lookup *map; > struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; > int ret; > + u64 feature; > > ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, > &chunk_offset); > @@ -2791,6 +2926,15 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, > chunk_size, stripe_size); > BUG_ON(ret); > + > + feature = btrfs_super_incompat_flags(&extent_root->fs_info->super_copy); > + if (feature & BTRFS_FEATURE_INCOMPAT_CHUNK_TREE_BACKUP) { > + ret = mark_chunk_stripes_header(extent_root, map, chunk_offset, > + chunk_size, stripe_size, type); > + if (ret) > + return ret; > + } > + > return 0; > } > > diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h > index 7af6144..7166a3b 100644 > --- a/fs/btrfs/volumes.h > +++ b/fs/btrfs/volumes.h > @@ -146,6 +146,31 @@ struct btrfs_device_info { > u64 max_avail; > }; > > +struct map_lookup { > + u64 type; > + int io_align; > + int io_width; > + int stripe_len; > + int sector_size; > + int num_stripes; > + int sub_stripes; > + struct btrfs_bio_stripe stripes[]; > +};already present in .h> + > +#define BTRFS_STRIPE_HEADER_MAGIC 111111this is not a *magic* number! :)> + > +struct btrfs_stripe_header { > + __le64 magic; > + __le64 chunk_offset; > + __le64 chunk_size; > + __le64 stripe_size; > + __le32 stripe_index; > + __le64 flag; > + u8 fsid[BTRFS_FSID_SIZE]; > +} __attribute__ ((__packed__));why is it packed? it''s an in-memory-only, ordering of stripe_index and flag will cause unaligned access of flag. though compiler knows this and will generate only more instructions, not really an unaligned access, but still a bit ineffective.> + > +int erase_chunk_stripes_header(struct btrfs_root *root, u64 chunk_offset); > + > /* Used to sort the devices by max_avail(descending sort) */ > int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);dave -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html