Btrfs: Add the ability to find and remove dead roots after a crash.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 77071f2..fb6fffb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -122,12 +122,12 @@
u8 fsid[16]; /* FS specific uuid */
__le64 blocknr; /* this block number */
__le64 magic;
- __le32 blocksize;
__le64 generation;
__le64 root;
__le64 total_blocks;
__le64 blocks_used;
__le64 root_dir_objectid;
+ __le32 blocksize;
} __attribute__ ((__packed__));
/*
@@ -226,10 +226,12 @@
struct btrfs_inode_item inode;
__le64 root_dirid;
__le64 blocknr;
- __le32 flags;
__le64 block_limit;
__le64 blocks_used;
+ __le32 flags;
__le32 refs;
+ struct btrfs_disk_key drop_progress;
+ u8 drop_level;
} __attribute__ ((__packed__));
#define BTRFS_FILE_EXTENT_REG 0
@@ -800,6 +802,16 @@
item->refs = cpu_to_le32(val);
}
+static inline u32 btrfs_root_flags(struct btrfs_root_item *item)
+{
+ return le32_to_cpu(item->flags);
+}
+
+static inline void btrfs_set_root_flags(struct btrfs_root_item *item, u32 val)
+{
+ item->flags = cpu_to_le32(val);
+}
+
static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)
{
return le64_to_cpu(s->blocknr);
@@ -1076,6 +1088,7 @@
*item);
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
btrfs_root_item *item, struct btrfs_key *key);
+int btrfs_find_dead_roots(struct btrfs_root *root);
/* dir-item.c */
int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, const char *name, int name_len, u64 dir,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 865a284..d7615e1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -326,8 +326,8 @@
return 0;
}
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
- struct btrfs_key *location)
+struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location)
{
struct btrfs_root *root;
struct btrfs_root *tree_root = fs_info->tree_root;
@@ -336,11 +336,7 @@
u64 highest_inode;
int ret = 0;
- root = radix_tree_lookup(&fs_info->fs_roots_radix,
- (unsigned long)location->objectid);
- if (root)
- return root;
- root = kmalloc(sizeof(*root), GFP_NOFS);
+ root = kzalloc(sizeof(*root), GFP_NOFS);
if (!root)
return ERR_PTR(-ENOMEM);
if (location->offset == (u64)-1) {
@@ -383,6 +379,28 @@
BUG_ON(!root->node);
insert:
root->ref_cows = 1;
+ ret = btrfs_find_highest_inode(root, &highest_inode);
+ if (ret == 0) {
+ root->highest_inode = highest_inode;
+ root->last_inode_alloc = highest_inode;
+ }
+ return root;
+}
+
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location)
+{
+ struct btrfs_root *root;
+ int ret;
+
+ root = radix_tree_lookup(&fs_info->fs_roots_radix,
+ (unsigned long)location->objectid);
+ if (root)
+ return root;
+
+ root = btrfs_read_fs_root_no_radix(fs_info, location);
+ if (IS_ERR(root))
+ return root;
ret = radix_tree_insert(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
root);
@@ -391,11 +409,6 @@
kfree(root);
return ERR_PTR(ret);
}
- ret = btrfs_find_highest_inode(root, &highest_inode);
- if (ret == 0) {
- root->highest_inode = highest_inode;
- root->last_inode_alloc = highest_inode;
- }
return root;
}
@@ -489,6 +502,9 @@
btrfs_read_block_groups(extent_root);
fs_info->generation = btrfs_super_generation(disk_super) + 1;
+ ret = btrfs_find_dead_roots(tree_root);
+ if (ret)
+ goto fail_tree_root;
mutex_unlock(&fs_info->fs_mutex);
return tree_root;
@@ -538,7 +554,7 @@
return 0;
}
-static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
{
radix_tree_delete(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid);
@@ -565,7 +581,7 @@
if (!ret)
break;
for (i = 0; i < ret; i++)
- free_fs_root(fs_info, gang[i]);
+ btrfs_free_fs_root(fs_info, gang[i]);
}
return 0;
}
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 7b76ccc..c4a695a 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -65,6 +65,8 @@
char *result);
struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
struct btrfs_key *location);
+struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location);
u64 bh_blocknr(struct buffer_head *bh);
int btrfs_insert_dev_radix(struct btrfs_root *root,
struct block_device *bdev,
@@ -75,4 +77,5 @@
u64 logical);
int btrfs_releasepage(struct page *page, gfp_t flags);
void btrfs_btree_balance_dirty(struct btrfs_root *root);
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
#endif
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6d031da..9d2a0a3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2028,6 +2028,8 @@
btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
btrfs_set_root_refs(&root_item, 1);
+ memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
+ root_item.drop_level = 0;
brelse(subvol);
subvol = NULL;
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index ac0fae7..737e5a3 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include "ctree.h"
+#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
@@ -32,7 +33,7 @@
search_key.objectid = objectid;
search_key.flags = (u32)-1;
- search_key.offset = (u32)-1;
+ search_key.offset = (u64)-1;
path = btrfs_alloc_path();
BUG_ON(!path);
@@ -50,6 +51,7 @@
memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
sizeof(*item));
btrfs_disk_key_to_cpu(key, &l->items[slot].key);
+printk("find last finds key %Lu %u %Lu slot %d search for obj %Lu\n", key->objectid, key->flags, key->offset, slot, objectid);
ret = 0;
out:
btrfs_release_path(root, path);
@@ -93,6 +95,67 @@
return ret;
}
+int btrfs_find_dead_roots(struct btrfs_root *root)
+{
+ struct btrfs_root *dead_root;
+ struct btrfs_item *item;
+ struct btrfs_root_item *ri;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ int ret;
+ u32 nritems;
+ struct btrfs_leaf *leaf;
+ int slot;
+
+ key.objectid = 0;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.offset = 0;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ while(1) {
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ nritems = btrfs_header_nritems(&leaf->header);
+ slot = path->slots[0];
+ if (slot >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ nritems = btrfs_header_nritems(&leaf->header);
+ slot = path->slots[0];
+ }
+ item = leaf->items + slot;
+ btrfs_disk_key_to_cpu(&key, &item->key);
+ if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
+ goto next;
+ ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
+ if (btrfs_root_refs(ri) != 0)
+ goto next;
+ dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
+ if (IS_ERR(root)) {
+ ret = PTR_ERR(root);
+ goto err;
+ }
+printk("found dead root %Lu %u %Lu\n", key.objectid, key.flags, key.offset);
+ ret = btrfs_add_dead_root(dead_root,
+ &root->fs_info->dead_roots);
+ if (ret)
+ goto err;
+next:
+ slot++;
+ path->slots[0]++;
+ }
+ ret = 0;
+err:
+ btrfs_free_path(path);
+ return ret;
+}
+
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_key *key)
{
@@ -111,14 +174,8 @@
path->slots[0], struct btrfs_root_item);
refs = btrfs_root_refs(ri);
- BUG_ON(refs == 0);
- if (refs == 1) {
- ret = btrfs_del_item(trans, root, path);
- } else {
- btrfs_set_root_refs(ri, refs - 1);
- WARN_ON(1);
- mark_buffer_dirty(path->nodes[0]);
- }
+ BUG_ON(refs != 0);
+ ret = btrfs_del_item(trans, root, path);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 321f885..85a2a5e 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -85,11 +85,15 @@
if (root != root->fs_info->tree_root && root->last_trans <
running_trans_id) {
- radix_tree_tag_set(&root->fs_info->fs_roots_radix,
- (unsigned long)root->root_key.objectid,
- BTRFS_ROOT_TRANS_TAG);
- root->commit_root = root->node;
- get_bh(root->node);
+ if (root->root_item.refs != 0) {
+ radix_tree_tag_set(&root->fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+ root->commit_root = root->node;
+ get_bh(root->node);
+ } else {
+ WARN_ON(1);
+ }
}
root->last_trans = running_trans_id;
h->transid = running_trans_id;
@@ -208,8 +212,24 @@
struct btrfs_key snap_key;
struct buffer_head *commit_root;
struct btrfs_root *root;
+ int free_on_drop;
};
+int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list)
+{
+ struct dirty_root *dirty;
+
+ dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
+ if (!dirty)
+ return -ENOMEM;
+ memcpy(&dirty->snap_key, &root->root_key, sizeof(root->root_key));
+ dirty->commit_root = root->node;
+ dirty->root = root;
+ dirty->free_on_drop = 1;
+ list_add(&dirty->list, dead_list);
+ return 0;
+}
+
static int add_dirty_roots(struct btrfs_trans_handle *trans,
struct radix_tree_root *radix,
struct list_head *list)
@@ -217,9 +237,11 @@
struct dirty_root *dirty;
struct btrfs_root *gang[8];
struct btrfs_root *root;
+ struct btrfs_root_item tmp_item;
int i;
int ret;
int err = 0;
+ u32 refs;
while(1) {
ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
@@ -246,6 +268,9 @@
dirty->commit_root = root->commit_root;
root->commit_root = NULL;
dirty->root = root;
+ dirty->free_on_drop = 0;
+ memcpy(&tmp_item, &root->root_item, sizeof(tmp_item));
+
root->root_key.offset = root->fs_info->generation;
btrfs_set_root_blocknr(&root->root_item,
bh_blocknr(root->node));
@@ -254,7 +279,18 @@
&root->root_item);
if (err)
break;
- list_add(&dirty->list, list);
+
+ refs = btrfs_root_refs(&tmp_item);
+ btrfs_set_root_refs(&tmp_item, refs - 1);
+ err = btrfs_update_root(trans, root->fs_info->tree_root,
+ &dirty->snap_key,
+ &tmp_item);
+
+ BUG_ON(err);
+ if (refs == 1)
+ list_add(&dirty->list, list);
+ else
+ kfree(dirty);
}
}
return err;
@@ -270,16 +306,20 @@
mutex_lock(&tree_root->fs_info->fs_mutex);
dirty = list_entry(list->next, struct dirty_root, list);
list_del_init(&dirty->list);
+
trans = btrfs_start_transaction(tree_root, 1);
+printk("deleting root %Lu %u %Lu\n", dirty->snap_key.objectid, dirty->snap_key.flags, dirty->snap_key.offset);
ret = btrfs_drop_snapshot(trans, dirty->root,
dirty->commit_root);
BUG_ON(ret);
-
ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
if (ret)
break;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
+
+ if (dirty->free_on_drop)
+ kfree(dirty->root);
kfree(dirty);
mutex_unlock(&tree_root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(tree_root);
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 5fb1d32..ebf44f3 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -69,5 +69,6 @@
void btrfs_transaction_queue_work(struct btrfs_root *root, int delay);
void btrfs_init_transaction_sys(void);
void btrfs_exit_transaction_sys(void);
+int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list);
#endif