/*
- * Copyright (C) 2007 Oracle. All rights reserved.
+ * Copyright (C) 2007,2008 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot);
-inline void btrfs_init_path(struct btrfs_path *p)
-{
- memset(p, 0, sizeof(*p));
-}
-
struct btrfs_path *btrfs_alloc_path(void)
{
struct btrfs_path *path;
- path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
- if (path) {
- btrfs_init_path(path);
+ path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
+ if (path)
path->reada = 1;
- }
return path;
}
+/*
+ * set all locked nodes in the path to blocking locks. This should
+ * be done before scheduling
+ */
+noinline void btrfs_set_path_blocking(struct btrfs_path *p)
+{
+ int i;
+ for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+ if (p->nodes[i] && p->locks[i])
+ btrfs_set_lock_blocking(p->nodes[i]);
+ }
+}
+
+/*
+ * reset all the locked nodes in the patch to spinning locks.
+ *
+ * held is used to keep lockdep happy, when lockdep is enabled
+ * we set held to a blocking lock before we go around and
+ * retake all the spinlocks in the path. You can safely use NULL
+ * for held
+ */
+noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
+ struct extent_buffer *held)
+{
+ int i;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /* lockdep really cares that we take all of these spinlocks
+ * in the right order. If any of the locks in the path are not
+ * currently blocking, it is going to complain. So, make really
+ * really sure by forcing the path to blocking before we clear
+ * the path blocking.
+ */
+ if (held)
+ btrfs_set_lock_blocking(held);
+ btrfs_set_path_blocking(p);
+#endif
+
+ for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
+ if (p->nodes[i] && p->locks[i])
+ btrfs_clear_lock_blocking(p->nodes[i]);
+ }
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ if (held)
+ btrfs_clear_lock_blocking(held);
+#endif
+}
+
+/* this also releases the path */
void btrfs_free_path(struct btrfs_path *p)
{
btrfs_release_path(NULL, p);
kmem_cache_free(btrfs_path_cachep, p);
}
-void noinline btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
+/*
+ * path release drops references on the extent buffers in the path
+ * and it drops any locks held by this path
+ *
+ * It is safe to call this on paths that no locks or extent buffers held.
+ */
+noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
{
int i;
}
}
+/*
+ * safely gets a reference on the root node of a tree. A lock
+ * is not taken, so a concurrent writer may put a different node
+ * at the root of the tree. See btrfs_lock_root_node for the
+ * looping required.
+ *
+ * The extent buffer returned by this has a reference taken, so
+ * it won't disappear. It may stop being the root of the tree
+ * at any time because there are no locks held.
+ */
struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
{
struct extent_buffer *eb;
return eb;
}
+/* loop around taking references on and locking the root node of the
+ * tree until you end up with a lock on the root. A locked buffer
+ * is returned, with a reference held.
+ */
struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
{
struct extent_buffer *eb;
- while(1) {
+ while (1) {
eb = btrfs_root_node(root);
btrfs_tree_lock(eb);
return eb;
}
+/* cowonly root (everything not a reference counted cow subvolume), just get
+ * put onto a simple dirty list. transaction.c walks this to make sure they
+ * get properly updated on disk.
+ */
static void add_root_to_dirty_list(struct btrfs_root *root)
{
if (root->track_dirty && list_empty(&root->dirty_list)) {
}
}
+/*
+ * used by snapshot creation to make a copy of a root for a tree with
+ * a given objectid. The buffer with the new root node is returned in
+ * cow_ret, and this func returns zero on success or a negative error code.
+ */
int btrfs_copy_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
btrfs_set_header_owner(cow, new_root_objectid);
btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
+ write_extent_buffer(cow, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(cow),
+ BTRFS_FSID_SIZE);
+
WARN_ON(btrfs_header_generation(buf) > trans->transid);
ret = btrfs_inc_ref(trans, new_root, buf, cow, NULL);
kfree(new_root);
return 0;
}
-int noinline __btrfs_cow_block(struct btrfs_trans_handle *trans,
+/*
+ * does the dirty work in cow of a single block. The parent block (if
+ * supplied) is updated to point to the new cow copy. The new buffer is marked
+ * dirty and returned locked. If you modify the block it needs to be marked
+ * dirty again.
+ *
+ * search_start -- an allocation hint for the new block
+ *
+ * empty_size -- a hint that you plan on doing more cow. This is the size in
+ * bytes the allocator should try to find free next to the block it returns.
+ * This is just a hint and may be ignored by the allocator.
+ */
+static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
struct extent_buffer *parent, int parent_slot,
struct extent_buffer **cow_ret,
- u64 search_start, u64 empty_size,
- u64 prealloc_dest)
+ u64 search_start, u64 empty_size)
{
u64 parent_start;
struct extent_buffer *cow;
if (*cow_ret == buf)
unlock_orig = 1;
- WARN_ON(!btrfs_tree_locked(buf));
+ btrfs_assert_tree_locked(buf);
if (parent)
parent_start = parent->start;
level = btrfs_header_level(buf);
nritems = btrfs_header_nritems(buf);
- if (prealloc_dest) {
- struct btrfs_key ins;
-
- ins.objectid = prealloc_dest;
- ins.offset = buf->len;
- ins.type = BTRFS_EXTENT_ITEM_KEY;
-
- ret = btrfs_alloc_reserved_extent(trans, root, parent_start,
- root->root_key.objectid,
- trans->transid, level, 0,
- &ins);
- BUG_ON(ret);
- cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
- buf->len);
- } else {
- cow = btrfs_alloc_free_block(trans, root, buf->len,
- parent_start,
- root->root_key.objectid,
- trans->transid, level,
- search_start, empty_size);
- }
+ cow = btrfs_alloc_free_block(trans, root, buf->len,
+ parent_start, root->root_key.objectid,
+ trans->transid, level,
+ search_start, empty_size);
if (IS_ERR(cow))
return PTR_ERR(cow);
+ /* cow is set to blocking by btrfs_init_new_buffer */
+
copy_extent_buffer(cow, buf, 0, 0, cow->len);
btrfs_set_header_bytenr(cow, cow->start);
btrfs_set_header_generation(cow, trans->transid);
btrfs_set_header_owner(cow, root->root_key.objectid);
btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
+ write_extent_buffer(cow, root->fs_info->fsid,
+ (unsigned long)btrfs_header_fsid(cow),
+ BTRFS_FSID_SIZE);
+
WARN_ON(btrfs_header_generation(buf) > trans->transid);
if (btrfs_header_generation(buf) != trans->transid) {
u32 nr_extents;
/*
* There are only two places that can drop reference to
* tree blocks owned by living reloc trees, one is here,
- * the other place is btrfs_merge_path. In both places,
+ * the other place is btrfs_drop_subtree. In both places,
* we check reference count while tree block is locked.
* Furthermore, if reference count is one, it won't get
* increased by someone else.
}
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
- ret = btrfs_add_reloc_mapping(root, buf->start,
- buf->len, cow->start);
- BUG_ON(ret);
ret = btrfs_reloc_tree_cache_ref(trans, root, cow, buf->start);
WARN_ON(ret);
}
buf->len, buf->start,
root->root_key.objectid,
btrfs_header_generation(buf),
- 0, 0, 1);
+ level, 1);
}
free_extent_buffer(buf);
add_root_to_dirty_list(root);
WARN_ON(btrfs_header_generation(parent) != trans->transid);
btrfs_free_extent(trans, root, buf->start, buf->len,
parent_start, btrfs_header_owner(parent),
- btrfs_header_generation(parent), 0, 0, 1);
+ btrfs_header_generation(parent), level, 1);
}
if (unlock_orig)
btrfs_tree_unlock(buf);
return 0;
}
-int noinline btrfs_cow_block(struct btrfs_trans_handle *trans,
+/*
+ * cows a single block, see __btrfs_cow_block for the real work.
+ * This version of it has extra checks so that a block isn't cow'd more than
+ * once per transaction, as long as it hasn't been written yet
+ */
+noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *buf,
struct extent_buffer *parent, int parent_slot,
- struct extent_buffer **cow_ret, u64 prealloc_dest)
+ struct extent_buffer **cow_ret)
{
u64 search_start;
int ret;
if (trans->transaction != root->fs_info->running_transaction) {
- printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
+ printk(KERN_CRIT "trans %llu running %llu\n",
+ (unsigned long long)trans->transid,
+ (unsigned long long)
root->fs_info->running_transaction->transid);
WARN_ON(1);
}
if (trans->transid != root->fs_info->generation) {
- printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
- root->fs_info->generation);
+ printk(KERN_CRIT "trans %llu running %llu\n",
+ (unsigned long long)trans->transid,
+ (unsigned long long)root->fs_info->generation);
WARN_ON(1);
}
- spin_lock(&root->fs_info->hash_lock);
if (btrfs_header_generation(buf) == trans->transid &&
btrfs_header_owner(buf) == root->root_key.objectid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
*cow_ret = buf;
- spin_unlock(&root->fs_info->hash_lock);
- WARN_ON(prealloc_dest);
return 0;
}
- spin_unlock(&root->fs_info->hash_lock);
+
search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
+
+ if (parent)
+ btrfs_set_lock_blocking(parent);
+ btrfs_set_lock_blocking(buf);
+
ret = __btrfs_cow_block(trans, root, buf, parent,
- parent_slot, cow_ret, search_start, 0,
- prealloc_dest);
+ parent_slot, cow_ret, search_start, 0);
return ret;
}
+/*
+ * helper function for defrag to decide if two blocks pointed to by a
+ * node are actually close by
+ */
static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
{
if (blocknr < other && other - (blocknr + blocksize) < 32768)
return 0;
}
+/*
+ * same as comp_keys only with two btrfs_key's
+ */
+static int comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
+{
+ if (k1->objectid > k2->objectid)
+ return 1;
+ if (k1->objectid < k2->objectid)
+ return -1;
+ if (k1->type > k2->type)
+ return 1;
+ if (k1->type < k2->type)
+ return -1;
+ if (k1->offset > k2->offset)
+ return 1;
+ if (k1->offset < k2->offset)
+ return -1;
+ return 0;
+}
+/*
+ * this is used by the defrag code to go through all the
+ * leaves pointed to by a node and reallocate them so that
+ * disk order is close to key order
+ */
int btrfs_realloc_node(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *parent,
int start_slot, int cache_only, u64 *last_ret,
if (cache_only && parent_level != 1)
return 0;
- if (trans->transaction != root->fs_info->running_transaction) {
- printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
- root->fs_info->running_transaction->transid);
+ if (trans->transaction != root->fs_info->running_transaction)
WARN_ON(1);
- }
- if (trans->transid != root->fs_info->generation) {
- printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
- root->fs_info->generation);
+ if (trans->transid != root->fs_info->generation)
WARN_ON(1);
- }
parent_nritems = btrfs_header_nritems(parent);
blocksize = btrfs_level_size(root, parent_level - 1);
if (parent_nritems == 1)
return 0;
+ btrfs_set_lock_blocking(parent);
+
for (i = start_slot; i < end_slot; i++) {
int close = 1;
search_start = last_block;
btrfs_tree_lock(cur);
+ btrfs_set_lock_blocking(cur);
err = __btrfs_cow_block(trans, root, cur, parent, i,
&cur, search_start,
min(16 * blocksize,
- (end_slot - i) * blocksize), 0);
+ (end_slot - i) * blocksize));
if (err) {
btrfs_tree_unlock(cur);
free_extent_buffer(cur);
return btrfs_item_offset_nr(leaf, nr - 1);
}
+/*
+ * extra debugging checks to make sure all the items in a key are
+ * well formed and in the proper order
+ */
static int check_node(struct btrfs_root *root, struct btrfs_path *path,
int level)
{
return 0;
}
+/*
+ * extra checking to make sure all the items in a leaf are
+ * well formed and in the proper order
+ */
static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
int level)
{
BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
btrfs_header_bytenr(leaf));
}
-#if 0
- for (i = 0; nritems > 1 && i < nritems - 2; i++) {
- btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
- btrfs_item_key(leaf, &leaf_key, i);
- if (comp_keys(&leaf_key, &cpukey) >= 0) {
- btrfs_print_leaf(root, leaf);
- printk("slot %d offset bad key\n", i);
- BUG_ON(1);
- }
- if (btrfs_item_offset_nr(leaf, i) !=
- btrfs_item_end_nr(leaf, i + 1)) {
- btrfs_print_leaf(root, leaf);
- printk("slot %d offset bad\n", i);
- BUG_ON(1);
- }
- if (i == 0) {
- if (btrfs_item_offset_nr(leaf, i) +
- btrfs_item_size_nr(leaf, i) !=
- BTRFS_LEAF_DATA_SIZE(root)) {
- btrfs_print_leaf(root, leaf);
- printk("slot %d first offset bad\n", i);
- BUG_ON(1);
- }
- }
- }
- if (nritems > 0) {
- if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
- btrfs_print_leaf(root, leaf);
- printk("slot %d bad size \n", nritems - 1);
- BUG_ON(1);
- }
- }
-#endif
if (slot != 0 && slot < nritems - 1) {
btrfs_item_key(leaf, &leaf_key, slot);
btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
if (comp_keys(&leaf_key, &cpukey) <= 0) {
btrfs_print_leaf(root, leaf);
- printk("slot %d offset bad key\n", slot);
+ printk(KERN_CRIT "slot %d offset bad key\n", slot);
BUG_ON(1);
}
if (btrfs_item_offset_nr(leaf, slot - 1) !=
btrfs_item_end_nr(leaf, slot)) {
btrfs_print_leaf(root, leaf);
- printk("slot %d offset bad\n", slot);
+ printk(KERN_CRIT "slot %d offset bad\n", slot);
BUG_ON(1);
}
}
if (btrfs_item_offset_nr(leaf, slot) !=
btrfs_item_end_nr(leaf, slot + 1)) {
btrfs_print_leaf(root, leaf);
- printk("slot %d offset bad\n", slot);
+ printk(KERN_CRIT "slot %d offset bad\n", slot);
BUG_ON(1);
}
}
return 0;
}
-static int noinline check_block(struct btrfs_root *root,
+static noinline int check_block(struct btrfs_root *root,
struct btrfs_path *path, int level)
{
- u64 found_start;
return 0;
- if (btrfs_header_level(path->nodes[level]) != level)
- printk("warning: bad level %Lu wanted %d found %d\n",
- path->nodes[level]->start, level,
- btrfs_header_level(path->nodes[level]));
- found_start = btrfs_header_bytenr(path->nodes[level]);
- if (found_start != path->nodes[level]->start) {
- printk("warning: bad bytentr %Lu found %Lu\n",
- path->nodes[level]->start, found_start);
- }
-#if 0
- struct extent_buffer *buf = path->nodes[level];
-
- if (memcmp_extent_buffer(buf, root->fs_info->fsid,
- (unsigned long)btrfs_header_fsid(buf),
- BTRFS_FSID_SIZE)) {
- printk("warning bad block %Lu\n", buf->start);
- return 1;
- }
-#endif
if (level == 0)
return check_leaf(root, path, level);
return check_node(root, path, level);
unsigned long map_len = 0;
int err;
- while(low < high) {
+ while (low < high) {
mid = (low + high) / 2;
offset = p + mid * item_size;
unmap_extent_buffer(eb, map_token, KM_USER0);
map_token = NULL;
}
- err = map_extent_buffer(eb, offset,
+
+ err = map_private_extent_buffer(eb, offset,
sizeof(struct btrfs_disk_key),
&map_token, &kaddr,
&map_start, &map_len, KM_USER0);
return -1;
}
+/* given a node and slot number, this reads the blocks it points to. The
+ * extent buffer is returned with a reference taken (but unlocked).
+ * NULL is returned on error.
+ */
static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
struct extent_buffer *parent, int slot)
{
btrfs_node_ptr_generation(parent, slot));
}
+/*
+ * node level balancing, used to make sure nodes are in proper order for
+ * item deletion. We balance from the top down, so we have to make sure
+ * that a deletion won't leave an node completely empty later on.
+ */
static noinline int balance_level(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int level)
return 0;
mid = path->nodes[level];
+
WARN_ON(!path->locks[level]);
WARN_ON(btrfs_header_generation(mid) != trans->transid);
/* promote the child to a root */
child = read_node_slot(root, mid, 0);
- btrfs_tree_lock(child);
BUG_ON(!child);
- ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
+ btrfs_tree_lock(child);
+ btrfs_set_lock_blocking(child);
+ ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
BUG_ON(ret);
spin_lock(&root->node_lock);
spin_unlock(&root->node_lock);
ret = btrfs_update_extent_ref(trans, root, child->start,
+ child->len,
mid->start, child->start,
root->root_key.objectid,
- trans->transid, level - 1, 0);
+ trans->transid, level - 1);
BUG_ON(ret);
add_root_to_dirty_list(root);
btrfs_tree_unlock(child);
+
path->locks[level] = 0;
path->nodes[level] = NULL;
clean_tree_block(trans, root, mid);
free_extent_buffer(mid);
ret = btrfs_free_extent(trans, root, mid->start, mid->len,
mid->start, root->root_key.objectid,
- btrfs_header_generation(mid), 0, 0, 1);
+ btrfs_header_generation(mid),
+ level, 1);
/* once for the root ptr */
free_extent_buffer(mid);
return ret;
BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
return 0;
+ if (trans->transaction->delayed_refs.flushing &&
+ btrfs_header_nritems(mid) > 2)
+ return 0;
+
if (btrfs_header_nritems(mid) < 2)
err_on_enospc = 1;
left = read_node_slot(root, parent, pslot - 1);
if (left) {
btrfs_tree_lock(left);
+ btrfs_set_lock_blocking(left);
wret = btrfs_cow_block(trans, root, left,
- parent, pslot - 1, &left, 0);
+ parent, pslot - 1, &left);
if (wret) {
ret = wret;
goto enospc;
right = read_node_slot(root, parent, pslot + 1);
if (right) {
btrfs_tree_lock(right);
+ btrfs_set_lock_blocking(right);
wret = btrfs_cow_block(trans, root, right,
- parent, pslot + 1, &right, 0);
+ parent, pslot + 1, &right);
if (wret) {
ret = wret;
goto enospc;
wret = btrfs_free_extent(trans, root, bytenr,
blocksize, parent->start,
btrfs_header_owner(parent),
- generation, 0, 0, 1);
+ generation, level, 1);
if (wret)
ret = wret;
} else {
wret = btrfs_free_extent(trans, root, bytenr, blocksize,
parent->start,
btrfs_header_owner(parent),
- root_gen, 0, 0, 1);
+ root_gen, level, 1);
if (wret)
ret = wret;
} else {
return ret;
}
-/* returns zero if the push worked, non-zero otherwise */
-static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
+/* Node balancing for insertion. Here we only split or push nodes around
+ * when they are completely full. This is also done top down, so we
+ * have to be pessimistic.
+ */
+static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int level)
{
u32 left_nr;
btrfs_tree_lock(left);
+ btrfs_set_lock_blocking(left);
+
left_nr = btrfs_header_nritems(left);
if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
wret = 1;
} else {
ret = btrfs_cow_block(trans, root, left, parent,
- pslot - 1, &left, 0);
+ pslot - 1, &left);
if (ret)
wret = 1;
else {
*/
if (right) {
u32 right_nr;
+
btrfs_tree_lock(right);
+ btrfs_set_lock_blocking(right);
+
right_nr = btrfs_header_nritems(right);
if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
wret = 1;
} else {
ret = btrfs_cow_block(trans, root, right,
parent, pslot + 1,
- &right, 0);
+ &right);
if (ret)
wret = 1;
else {
}
/*
- * readahead one full node of leaves
+ * readahead one full node of leaves, finding things that are close
+ * to the block in 'slot', and triggering ra on them.
*/
-static noinline void reada_for_search(struct btrfs_root *root,
- struct btrfs_path *path,
- int level, int slot, u64 objectid)
+static void reada_for_search(struct btrfs_root *root,
+ struct btrfs_path *path,
+ int level, int slot, u64 objectid)
{
struct extent_buffer *node;
struct btrfs_disk_key disk_key;
u32 nritems;
u64 search;
- u64 lowest_read;
- u64 highest_read;
+ u64 target;
u64 nread = 0;
int direction = path->reada;
struct extent_buffer *eb;
return;
}
- highest_read = search;
- lowest_read = search;
+ target = search;
nritems = btrfs_header_nritems(node);
nr = slot;
- while(1) {
+ while (1) {
if (direction < 0) {
if (nr == 0)
break;
break;
}
search = btrfs_node_blockptr(node, nr);
- if ((search >= lowest_read && search <= highest_read) ||
- (search < lowest_read && lowest_read - search <= 32768) ||
- (search > highest_read && search - highest_read <= 32768)) {
+ if ((search <= target && target - search <= 65536) ||
+ (search > target && search - target <= 65536)) {
readahead_tree_block(root, search, blocksize,
btrfs_node_ptr_generation(node, nr));
nread += blocksize;
}
nscan++;
- if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
- break;
- if(nread > (1024 * 1024) || nscan > 128)
+ if ((nread > 65536 || nscan > 32))
break;
+ }
+}
+
+/*
+ * returns -EAGAIN if it had to drop the path, or zero if everything was in
+ * cache
+ */
+static noinline int reada_for_balance(struct btrfs_root *root,
+ struct btrfs_path *path, int level)
+{
+ int slot;
+ int nritems;
+ struct extent_buffer *parent;
+ struct extent_buffer *eb;
+ u64 gen;
+ u64 block1 = 0;
+ u64 block2 = 0;
+ int ret = 0;
+ int blocksize;
- if (search < lowest_read)
- lowest_read = search;
- if (search > highest_read)
- highest_read = search;
+ parent = path->nodes[level + 1];
+ if (!parent)
+ return 0;
+
+ nritems = btrfs_header_nritems(parent);
+ slot = path->slots[level + 1];
+ blocksize = btrfs_level_size(root, level);
+
+ if (slot > 0) {
+ block1 = btrfs_node_blockptr(parent, slot - 1);
+ gen = btrfs_node_ptr_generation(parent, slot - 1);
+ eb = btrfs_find_tree_block(root, block1, blocksize);
+ if (eb && btrfs_buffer_uptodate(eb, gen))
+ block1 = 0;
+ free_extent_buffer(eb);
+ }
+ if (slot + 1 < nritems) {
+ block2 = btrfs_node_blockptr(parent, slot + 1);
+ gen = btrfs_node_ptr_generation(parent, slot + 1);
+ eb = btrfs_find_tree_block(root, block2, blocksize);
+ if (eb && btrfs_buffer_uptodate(eb, gen))
+ block2 = 0;
+ free_extent_buffer(eb);
+ }
+ if (block1 || block2) {
+ ret = -EAGAIN;
+
+ /* release the whole path */
+ btrfs_release_path(root, path);
+
+ /* read the blocks */
+ if (block1)
+ readahead_tree_block(root, block1, blocksize, 0);
+ if (block2)
+ readahead_tree_block(root, block2, blocksize, 0);
+
+ if (block1) {
+ eb = read_tree_block(root, block1, blocksize, 0);
+ free_extent_buffer(eb);
+ }
+ if (block2) {
+ eb = read_tree_block(root, block2, blocksize, 0);
+ free_extent_buffer(eb);
+ }
}
+ return ret;
}
+
+/*
+ * when we walk down the tree, it is usually safe to unlock the higher layers
+ * in the tree. The exceptions are when our path goes through slot 0, because
+ * operations on the tree might require changing key pointers higher up in the
+ * tree.
+ *
+ * callers might also have set path->keep_locks, which tells this code to keep
+ * the lock if the path points to the last slot in the block. This is part of
+ * walking through the tree, and selecting the next slot in the higher block.
+ *
+ * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
+ * if lowest_unlock is 1, level 0 won't be unlocked
+ */
static noinline void unlock_up(struct btrfs_path *path, int level,
int lowest_unlock)
{
}
/*
+ * This releases any locks held in the path starting at level and
+ * going all the way up to the root.
+ *
+ * btrfs_search_slot will keep the lock held on higher nodes in a few
+ * corner cases, such as COW of the block at slot zero in the node. This
+ * ignores those rules, and it should only be called when there are no
+ * more updates to be done higher up in the tree.
+ */
+noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
+{
+ int i;
+
+ if (path->keep_locks || path->lowest_level)
+ return;
+
+ for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+ if (!path->nodes[i])
+ continue;
+ if (!path->locks[i])
+ continue;
+ btrfs_tree_unlock(path->nodes[i]);
+ path->locks[i] = 0;
+ }
+}
+
+/*
+ * helper function for btrfs_search_slot. The goal is to find a block
+ * in cache without setting the path to blocking. If we find the block
+ * we return zero and the path is unchanged.
+ *
+ * If we can't find the block, we set the path blocking and do some
+ * reada. -EAGAIN is returned and the search must be repeated.
+ */
+static int
+read_block_for_search(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *p,
+ struct extent_buffer **eb_ret, int level, int slot,
+ struct btrfs_key *key)
+{
+ u64 blocknr;
+ u64 gen;
+ u32 blocksize;
+ struct extent_buffer *b = *eb_ret;
+ struct extent_buffer *tmp;
+
+ blocknr = btrfs_node_blockptr(b, slot);
+ gen = btrfs_node_ptr_generation(b, slot);
+ blocksize = btrfs_level_size(root, level - 1);
+
+ tmp = btrfs_find_tree_block(root, blocknr, blocksize);
+ if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+ *eb_ret = tmp;
+ return 0;
+ }
+
+ /*
+ * reduce lock contention at high levels
+ * of the btree by dropping locks before
+ * we read.
+ */
+ btrfs_unlock_up_safe(p, level + 1);
+ btrfs_set_path_blocking(p);
+
+ if (tmp)
+ free_extent_buffer(tmp);
+ if (p->reada)
+ reada_for_search(root, p, level, slot, key->objectid);
+
+ btrfs_release_path(NULL, p);
+ tmp = read_tree_block(root, blocknr, blocksize, gen);
+ if (tmp)
+ free_extent_buffer(tmp);
+ return -EAGAIN;
+}
+
+/*
+ * helper function for btrfs_search_slot. This does all of the checks
+ * for node-level blocks and does any balancing required based on
+ * the ins_len.
+ *
+ * If no extra work was required, zero is returned. If we had to
+ * drop the path, -EAGAIN is returned and btrfs_search_slot must
+ * start over
+ */
+static int
+setup_nodes_for_search(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *p,
+ struct extent_buffer *b, int level, int ins_len)
+{
+ int ret;
+ if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
+ BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
+ int sret;
+
+ sret = reada_for_balance(root, p, level);
+ if (sret)
+ goto again;
+
+ btrfs_set_path_blocking(p);
+ sret = split_node(trans, root, p, level);
+ btrfs_clear_path_blocking(p, NULL);
+
+ BUG_ON(sret > 0);
+ if (sret) {
+ ret = sret;
+ goto done;
+ }
+ b = p->nodes[level];
+ } else if (ins_len < 0 && btrfs_header_nritems(b) <
+ BTRFS_NODEPTRS_PER_BLOCK(root) / 4) {
+ int sret;
+
+ sret = reada_for_balance(root, p, level);
+ if (sret)
+ goto again;
+
+ btrfs_set_path_blocking(p);
+ sret = balance_level(trans, root, p, level);
+ btrfs_clear_path_blocking(p, NULL);
+
+ if (sret) {
+ ret = sret;
+ goto done;
+ }
+ b = p->nodes[level];
+ if (!b) {
+ btrfs_release_path(NULL, p);
+ goto again;
+ }
+ BUG_ON(btrfs_header_nritems(b) == 1);
+ }
+ return 0;
+
+again:
+ ret = -EAGAIN;
+done:
+ return ret;
+}
+
+/*
* look for key in the tree. path is filled in with nodes along the way
* if key is found, we return zero and you can find the item in the leaf
* level of the path (level 0)
ins_len, int cow)
{
struct extent_buffer *b;
- struct extent_buffer *tmp;
int slot;
int ret;
int level;
- int should_reada = p->reada;
int lowest_unlock = 1;
- int blocksize;
u8 lowest_level = 0;
- u64 blocknr;
- u64 gen;
- struct btrfs_key prealloc_block;
lowest_level = p->lowest_level;
- WARN_ON(lowest_level && ins_len);
+ WARN_ON(lowest_level && ins_len > 0);
WARN_ON(p->nodes[0] != NULL);
- WARN_ON(cow && root == root->fs_info->extent_root &&
- !mutex_is_locked(&root->fs_info->alloc_mutex));
+
if (ins_len < 0)
lowest_unlock = 2;
- prealloc_block.objectid = 0;
-
again:
if (p->skip_locking)
b = btrfs_root_node(root);
if (cow) {
int wret;
- /* is a cow on this block not required */
- spin_lock(&root->fs_info->hash_lock);
+ /*
+ * if we don't really need to cow this block
+ * then we don't want to set the path blocking,
+ * so we test it here
+ */
if (btrfs_header_generation(b) == trans->transid &&
btrfs_header_owner(b) == root->root_key.objectid &&
!btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
- spin_unlock(&root->fs_info->hash_lock);
goto cow_done;
}
- spin_unlock(&root->fs_info->hash_lock);
-
- /* ok, we have to cow, is our old prealloc the right
- * size?
- */
- if (prealloc_block.objectid &&
- prealloc_block.offset != b->len) {
- btrfs_free_reserved_extent(root,
- prealloc_block.objectid,
- prealloc_block.offset);
- prealloc_block.objectid = 0;
- }
-
- /*
- * for higher level blocks, try not to allocate blocks
- * with the block and the parent locks held.
- */
- if (level > 1 && !prealloc_block.objectid &&
- btrfs_path_lock_waiting(p, level)) {
- u32 size = b->len;
- u64 hint = b->start;
-
- btrfs_release_path(root, p);
- ret = btrfs_reserve_extent(trans, root,
- size, size, 0,
- hint, (u64)-1,
- &prealloc_block, 0);
- BUG_ON(ret);
- goto again;
- }
+ btrfs_set_path_blocking(p);
wret = btrfs_cow_block(trans, root, b,
p->nodes[level + 1],
- p->slots[level + 1],
- &b, prealloc_block.objectid);
- prealloc_block.objectid = 0;
+ p->slots[level + 1], &b);
if (wret) {
free_extent_buffer(b);
ret = wret;
if (!p->skip_locking)
p->locks[level] = 1;
+ btrfs_clear_path_blocking(p, NULL);
+
+ /*
+ * we have a lock on b and as long as we aren't changing
+ * the tree, there is no way to for the items in b to change.
+ * It is safe to drop the lock on our parent before we
+ * go through the expensive btree search on b.
+ *
+ * If cow is true, then we might be changing slot zero,
+ * which may require changing the parent. So, we can't
+ * drop the lock until after we know which slot we're
+ * operating on.
+ */
+ if (!cow)
+ btrfs_unlock_up_safe(p, level + 1);
+
ret = check_block(root, p, level);
if (ret) {
ret = -1;
}
ret = bin_search(b, key, level, &slot);
+
if (level != 0) {
if (ret && slot > 0)
slot -= 1;
p->slots[level] = slot;
- if (ins_len > 0 && btrfs_header_nritems(b) >=
- BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
- int sret = split_node(trans, root, p, level);
- BUG_ON(sret > 0);
- if (sret) {
- ret = sret;
- goto done;
- }
- b = p->nodes[level];
- slot = p->slots[level];
- } else if (ins_len < 0) {
- int sret = balance_level(trans, root, p,
- level);
- if (sret) {
- ret = sret;
- goto done;
- }
- b = p->nodes[level];
- if (!b) {
- btrfs_release_path(NULL, p);
- goto again;
- }
- slot = p->slots[level];
- BUG_ON(btrfs_header_nritems(b) == 1);
- }
+ ret = setup_nodes_for_search(trans, root, p, b, level,
+ ins_len);
+ if (ret == -EAGAIN)
+ goto again;
+ else if (ret)
+ goto done;
+ b = p->nodes[level];
+ slot = p->slots[level];
+
unlock_up(p, level, lowest_unlock);
/* this is only true while dropping a snapshot */
goto done;
}
- blocknr = btrfs_node_blockptr(b, slot);
- gen = btrfs_node_ptr_generation(b, slot);
- blocksize = btrfs_level_size(root, level - 1);
+ ret = read_block_for_search(trans, root, p,
+ &b, level, slot, key);
+ if (ret == -EAGAIN)
+ goto again;
- tmp = btrfs_find_tree_block(root, blocknr, blocksize);
- if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
- b = tmp;
- } else {
- /*
- * reduce lock contention at high levels
- * of the btree by dropping locks before
- * we read.
- */
- if (level > 1) {
- btrfs_release_path(NULL, p);
- if (tmp)
- free_extent_buffer(tmp);
- if (should_reada)
- reada_for_search(root, p,
- level, slot,
- key->objectid);
-
- tmp = read_tree_block(root, blocknr,
- blocksize, gen);
- if (tmp)
- free_extent_buffer(tmp);
- goto again;
- } else {
- if (tmp)
- free_extent_buffer(tmp);
- if (should_reada)
- reada_for_search(root, p,
- level, slot,
- key->objectid);
- b = read_node_slot(root, b, slot);
- }
+ if (!p->skip_locking) {
+ int lret;
+
+ btrfs_clear_path_blocking(p, NULL);
+ lret = btrfs_try_spin_lock(b);
+
+ if (!lret) {
+ btrfs_set_path_blocking(p);
+ btrfs_tree_lock(b);
+ btrfs_clear_path_blocking(p, b);
+ }
}
- if (!p->skip_locking)
- btrfs_tree_lock(b);
} else {
p->slots[level] = slot;
- if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
- sizeof(struct btrfs_item) + ins_len) {
- int sret = split_leaf(trans, root, key,
+ if (ins_len > 0 &&
+ btrfs_leaf_free_space(root, b) < ins_len) {
+ int sret;
+
+ btrfs_set_path_blocking(p);
+ sret = split_leaf(trans, root, key,
p, ins_len, ret == 0);
+ btrfs_clear_path_blocking(p, NULL);
+
BUG_ON(sret > 0);
if (sret) {
ret = sret;
goto done;
}
}
- unlock_up(p, level, lowest_unlock);
+ if (!p->search_for_split)
+ unlock_up(p, level, lowest_unlock);
goto done;
}
}
ret = 1;
done:
- if (prealloc_block.objectid) {
- btrfs_free_reserved_extent(root,
- prealloc_block.objectid,
- prealloc_block.offset);
- }
-
+ /*
+ * we don't really know what they plan on doing with the path
+ * from here on, so for now just mark it as blocking
+ */
+ if (!p->leave_spinning)
+ btrfs_set_path_blocking(p);
return ret;
}
int ret;
eb = btrfs_lock_root_node(root);
- ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
+ ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb);
BUG_ON(ret);
+ btrfs_set_lock_blocking(eb);
+
parent = eb;
while (1) {
level = btrfs_header_level(parent);
btrfs_node_key_to_cpu(eb, &key, slot);
key_match = !memcmp(&key, &node_keys[level - 1], sizeof(key));
+ if (generation == trans->transid) {
+ eb = read_tree_block(root, bytenr, blocksize,
+ generation);
+ btrfs_tree_lock(eb);
+ btrfs_set_lock_blocking(eb);
+ }
+
/*
* if node keys match and node pointer hasn't been modified
* in the running transaction, we can merge the path. for
- * reloc trees, the node pointer check is skipped, this is
- * because the reloc trees are fully controlled by the space
- * balance code, no one else can modify them.
+ * blocks owened by reloc trees, the node pointer check is
+ * skipped, this is because these blocks are fully controlled
+ * by the space balance code, no one else can modify them.
*/
if (!nodes[level - 1] || !key_match ||
(generation == trans->transid &&
- root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)) {
-next_level:
- if (level == 1 || level == lowest_level + 1)
+ btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID)) {
+ if (level == 1 || level == lowest_level + 1) {
+ if (generation == trans->transid) {
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+ }
break;
+ }
- eb = read_tree_block(root, bytenr, blocksize,
- generation);
- btrfs_tree_lock(eb);
+ if (generation != trans->transid) {
+ eb = read_tree_block(root, bytenr, blocksize,
+ generation);
+ btrfs_tree_lock(eb);
+ btrfs_set_lock_blocking(eb);
+ }
ret = btrfs_cow_block(trans, root, eb, parent, slot,
- &eb, 0);
+ &eb);
BUG_ON(ret);
+ if (root->root_key.objectid ==
+ BTRFS_TREE_RELOC_OBJECTID) {
+ if (!nodes[level - 1]) {
+ nodes[level - 1] = eb->start;
+ memcpy(&node_keys[level - 1], &key,
+ sizeof(node_keys[0]));
+ } else {
+ WARN_ON(1);
+ }
+ }
+
btrfs_tree_unlock(parent);
free_extent_buffer(parent);
parent = eb;
continue;
}
- if (generation == trans->transid) {
- u32 refs;
- BUG_ON(btrfs_header_owner(eb) !=
- BTRFS_TREE_RELOC_OBJECTID);
- /*
- * lock the block to keep __btrfs_cow_block from
- * changing the reference count.
- */
- eb = read_tree_block(root, bytenr, blocksize,
- generation);
- btrfs_tree_lock(eb);
-
- ret = btrfs_lookup_extent_ref(trans, root, bytenr,
- blocksize, &refs);
- BUG_ON(ret);
- /*
- * if replace block whose reference count is one,
- * we have to "drop the subtree". so skip it for
- * simplicity
- */
- if (refs == 1) {
- btrfs_tree_unlock(eb);
- free_extent_buffer(eb);
- goto next_level;
- }
- }
-
btrfs_set_node_blockptr(parent, slot, nodes[level - 1]);
btrfs_set_node_ptr_generation(parent, slot, trans->transid);
btrfs_mark_buffer_dirty(parent);
blocksize, parent->start,
btrfs_header_owner(parent),
btrfs_header_generation(parent),
- level - 1, 0);
- BUG_ON(ret);
- ret = btrfs_free_extent(trans, root, bytenr,
- blocksize, parent->start,
- btrfs_header_owner(parent),
- btrfs_header_generation(parent),
- level - 1, 0, 1);
+ level - 1);
BUG_ON(ret);
+ /*
+ * If the block was created in the running transaction,
+ * it's possible this is the last reference to it, so we
+ * should drop the subtree.
+ */
if (generation == trans->transid) {
+ ret = btrfs_drop_subtree(trans, root, eb, parent);
+ BUG_ON(ret);
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
+ } else {
+ ret = btrfs_free_extent(trans, root, bytenr,
+ blocksize, parent->start,
+ btrfs_header_owner(parent),
+ btrfs_header_generation(parent),
+ level - 1, 1);
+ BUG_ON(ret);
}
break;
}
if (!empty && src_nritems <= 8)
return 1;
- if (push_items <= 0) {
+ if (push_items <= 0)
return 1;
- }
if (empty) {
push_items = min(src_nritems, push_items);
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(dst_nritems),
btrfs_node_key_ptr_offset(0),
- push_items * sizeof(struct btrfs_key_ptr));
+ push_items * sizeof(struct btrfs_key_ptr));
if (push_items < src_nritems) {
memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
src_nritems = btrfs_header_nritems(src);
dst_nritems = btrfs_header_nritems(dst);
push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
- if (push_items <= 0) {
+ if (push_items <= 0)
return 1;
- }
- if (src_nritems < 4) {
+ if (src_nritems < 4)
return 1;
- }
max_push = src_nritems / 2 + 1;
/* don't try to empty the node */
- if (max_push >= src_nritems) {
+ if (max_push >= src_nritems)
return 1;
- }
if (max_push < push_items)
push_items = max_push;
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(0),
btrfs_node_key_ptr_offset(src_nritems - push_items),
- push_items * sizeof(struct btrfs_key_ptr));
+ push_items * sizeof(struct btrfs_key_ptr));
btrfs_set_header_nritems(src, src_nritems - push_items);
btrfs_set_header_nritems(dst, dst_nritems + push_items);
*
* returns zero on success or < 0 on failure.
*/
-static int noinline insert_new_root(struct btrfs_trans_handle *trans,
+static noinline int insert_new_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int level)
{
spin_unlock(&root->node_lock);
ret = btrfs_update_extent_ref(trans, root, lower->start,
- lower->start, c->start,
+ lower->len, lower->start, c->start,
root->root_key.objectid,
- trans->transid, level - 1, 0);
+ trans->transid, level - 1);
BUG_ON(ret);
/* the super has an extra ref to root->node */
BUG_ON(!path->nodes[level]);
lower = path->nodes[level];
nritems = btrfs_header_nritems(lower);
- if (slot > nritems)
- BUG();
+ BUG_ON(slot > nritems);
if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
BUG();
if (slot != nritems) {
ret = insert_new_root(trans, root, path, level + 1);
if (ret)
return ret;
- } else {
+ } else if (!trans->transaction->delayed_refs.flushing) {
ret = push_nodes_for_insert(trans, root, path, level);
c = path->nodes[level];
if (!ret && btrfs_header_nritems(c) <
* the start of the leaf data. IOW, how much room
* the leaf has left for both items and data
*/
-int noinline btrfs_leaf_free_space(struct btrfs_root *root,
+noinline int btrfs_leaf_free_space(struct btrfs_root *root,
struct extent_buffer *leaf)
{
int nritems = btrfs_header_nritems(leaf);
int ret;
ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
if (ret < 0) {
- printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
+ printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, "
+ "used %d nritems %d\n",
ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
leaf_space_used(leaf, 0, nritems), nritems);
}
return ret;
}
-/*
- * push some data in the path leaf to the right, trying to free up at
- * least data_size bytes. returns zero if the push worked, nonzero otherwise
- *
- * returns 1 if the push failed because the other node didn't have enough
- * room, 0 if everything worked out and < 0 if there were major errors.
- */
-static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size,
- int empty)
+static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ int data_size, int empty,
+ struct extent_buffer *right,
+ int free_space, u32 left_nritems)
{
struct extent_buffer *left = path->nodes[0];
- struct extent_buffer *right;
- struct extent_buffer *upper;
+ struct extent_buffer *upper = path->nodes[1];
struct btrfs_disk_key disk_key;
int slot;
u32 i;
- int free_space;
int push_space = 0;
int push_items = 0;
struct btrfs_item *item;
- u32 left_nritems;
u32 nr;
u32 right_nritems;
u32 data_end;
u32 this_item_size;
int ret;
- slot = path->slots[1];
- if (!path->nodes[1]) {
- return 1;
- }
- upper = path->nodes[1];
- if (slot >= btrfs_header_nritems(upper) - 1)
- return 1;
-
- WARN_ON(!btrfs_tree_locked(path->nodes[1]));
-
- right = read_node_slot(root, upper, slot + 1);
- btrfs_tree_lock(right);
- free_space = btrfs_leaf_free_space(root, right);
- if (free_space < data_size + sizeof(struct btrfs_item))
- goto out_unlock;
-
- /* cow and double check */
- ret = btrfs_cow_block(trans, root, right, upper,
- slot + 1, &right, 0);
- if (ret)
- goto out_unlock;
-
- free_space = btrfs_leaf_free_space(root, right);
- if (free_space < data_size + sizeof(struct btrfs_item))
- goto out_unlock;
-
- left_nritems = btrfs_header_nritems(left);
- if (left_nritems == 0)
- goto out_unlock;
-
if (empty)
nr = 0;
else
nr = 1;
if (path->slots[0] >= left_nritems)
- push_space += data_size + sizeof(*item);
+ push_space += data_size;
+ slot = path->slots[1];
i = left_nritems - 1;
while (i >= nr) {
item = btrfs_item_nr(left, i);
}
if (path->slots[0] == i)
- push_space += data_size + sizeof(*item);
+ push_space += data_size;
if (!left->map_token) {
map_extent_buffer(left, (unsigned long)item,
}
/*
+ * push some data in the path leaf to the right, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
+{
+ struct extent_buffer *left = path->nodes[0];
+ struct extent_buffer *right;
+ struct extent_buffer *upper;
+ int slot;
+ int free_space;
+ u32 left_nritems;
+ int ret;
+
+ if (!path->nodes[1])
+ return 1;
+
+ slot = path->slots[1];
+ upper = path->nodes[1];
+ if (slot >= btrfs_header_nritems(upper) - 1)
+ return 1;
+
+ btrfs_assert_tree_locked(path->nodes[1]);
+
+ right = read_node_slot(root, upper, slot + 1);
+ btrfs_tree_lock(right);
+ btrfs_set_lock_blocking(right);
+
+ free_space = btrfs_leaf_free_space(root, right);
+ if (free_space < data_size)
+ goto out_unlock;
+
+ /* cow and double check */
+ ret = btrfs_cow_block(trans, root, right, upper,
+ slot + 1, &right);
+ if (ret)
+ goto out_unlock;
+
+ free_space = btrfs_leaf_free_space(root, right);
+ if (free_space < data_size)
+ goto out_unlock;
+
+ left_nritems = btrfs_header_nritems(left);
+ if (left_nritems == 0)
+ goto out_unlock;
+
+ return __push_leaf_right(trans, root, path, data_size, empty,
+ right, free_space, left_nritems);
+out_unlock:
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ return 1;
+}
+
+/*
* push some data in the path leaf to the left, trying to free up at
* least data_size bytes. returns zero if the push worked, nonzero otherwise
*/
-static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
- *root, struct btrfs_path *path, int data_size,
- int empty)
+static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int data_size,
+ int empty, struct extent_buffer *left,
+ int free_space, int right_nritems)
{
struct btrfs_disk_key disk_key;
struct extent_buffer *right = path->nodes[0];
- struct extent_buffer *left;
int slot;
int i;
- int free_space;
int push_space = 0;
int push_items = 0;
struct btrfs_item *item;
u32 old_left_nritems;
- u32 right_nritems;
u32 nr;
int ret = 0;
int wret;
u32 old_left_item_size;
slot = path->slots[1];
- if (slot == 0)
- return 1;
- if (!path->nodes[1])
- return 1;
-
- right_nritems = btrfs_header_nritems(right);
- if (right_nritems == 0) {
- return 1;
- }
-
- WARN_ON(!btrfs_tree_locked(path->nodes[1]));
-
- left = read_node_slot(root, path->nodes[1], slot - 1);
- btrfs_tree_lock(left);
- free_space = btrfs_leaf_free_space(root, left);
- if (free_space < data_size + sizeof(struct btrfs_item)) {
- ret = 1;
- goto out;
- }
-
- /* cow and double check */
- ret = btrfs_cow_block(trans, root, left,
- path->nodes[1], slot - 1, &left, 0);
- if (ret) {
- /* we hit -ENOSPC, but it isn't fatal here */
- ret = 1;
- goto out;
- }
-
- free_space = btrfs_leaf_free_space(root, left);
- if (free_space < data_size + sizeof(struct btrfs_item)) {
- ret = 1;
- goto out;
- }
if (empty)
nr = right_nritems;
}
if (path->slots[0] == i)
- push_space += data_size + sizeof(*item);
+ push_space += data_size;
this_item_size = btrfs_item_size(right, item);
if (this_item_size + sizeof(*item) + push_space > free_space)
push_items * sizeof(struct btrfs_item));
push_space = BTRFS_LEAF_DATA_SIZE(root) -
- btrfs_item_offset_nr(right, push_items -1);
+ btrfs_item_offset_nr(right, push_items - 1);
copy_extent_buffer(left, right, btrfs_leaf_data(left) +
leaf_data_end(root, left) - push_space,
btrfs_item_offset_nr(right, push_items - 1),
push_space);
old_left_nritems = btrfs_header_nritems(left);
- BUG_ON(old_left_nritems < 0);
+ BUG_ON(old_left_nritems <= 0);
old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
/* fixup right node */
if (push_items > right_nritems) {
- printk("push items %d nr %u\n", push_items, right_nritems);
+ printk(KERN_CRIT "push items %d nr %u\n", push_items,
+ right_nritems);
WARN_ON(1);
}
}
/*
+ * push some data in the path leaf to the left, trying to free up at
+ * least data_size bytes. returns zero if the push worked, nonzero otherwise
+ */
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path, int data_size,
+ int empty)
+{
+ struct extent_buffer *right = path->nodes[0];
+ struct extent_buffer *left;
+ int slot;
+ int free_space;
+ u32 right_nritems;
+ int ret = 0;
+
+ slot = path->slots[1];
+ if (slot == 0)
+ return 1;
+ if (!path->nodes[1])
+ return 1;
+
+ right_nritems = btrfs_header_nritems(right);
+ if (right_nritems == 0)
+ return 1;
+
+ btrfs_assert_tree_locked(path->nodes[1]);
+
+ left = read_node_slot(root, path->nodes[1], slot - 1);
+ btrfs_tree_lock(left);
+ btrfs_set_lock_blocking(left);
+
+ free_space = btrfs_leaf_free_space(root, left);
+ if (free_space < data_size) {
+ ret = 1;
+ goto out;
+ }
+
+ /* cow and double check */
+ ret = btrfs_cow_block(trans, root, left,
+ path->nodes[1], slot - 1, &left);
+ if (ret) {
+ /* we hit -ENOSPC, but it isn't fatal here */
+ ret = 1;
+ goto out;
+ }
+
+ free_space = btrfs_leaf_free_space(root, left);
+ if (free_space < data_size) {
+ ret = 1;
+ goto out;
+ }
+
+ return __push_leaf_left(trans, root, path, data_size,
+ empty, left, free_space, right_nritems);
+out:
+ btrfs_tree_unlock(left);
+ free_extent_buffer(left);
+ return ret;
+}
+
+/*
* split the path's leaf in two, making sure there is at least data_size
* available for the resulting leaf level of the path.
*
* returns 0 if all went well and < 0 on failure.
*/
-static noinline int split_leaf(struct btrfs_trans_handle *trans,
+static noinline int copy_for_split(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
- struct btrfs_key *ins_key,
- struct btrfs_path *path, int data_size,
- int extend)
+ struct btrfs_path *path,
+ struct extent_buffer *l,
+ struct extent_buffer *right,
+ int slot, int mid, int nritems)
{
- struct extent_buffer *l;
- u32 nritems;
- int mid;
- int slot;
- struct extent_buffer *right;
- int space_needed = data_size + sizeof(struct btrfs_item);
int data_copy_size;
int rt_data_off;
int i;
int ret = 0;
int wret;
- int double_split;
- int num_doubles = 0;
struct btrfs_disk_key disk_key;
- if (extend)
- space_needed = data_size;
+ nritems = nritems - mid;
+ btrfs_set_header_nritems(right, nritems);
+ data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
- /* first try to make some room by pushing left and right */
- if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
- wret = push_leaf_right(trans, root, path, data_size, 0);
- if (wret < 0) {
- return wret;
+ copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
+ btrfs_item_nr_offset(mid),
+ nritems * sizeof(struct btrfs_item));
+
+ copy_extent_buffer(right, l,
+ btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+ data_copy_size, btrfs_leaf_data(l) +
+ leaf_data_end(root, l), data_copy_size);
+
+ rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
+ btrfs_item_end_nr(l, mid);
+
+ for (i = 0; i < nritems; i++) {
+ struct btrfs_item *item = btrfs_item_nr(right, i);
+ u32 ioff;
+
+ if (!right->map_token) {
+ map_extent_buffer(right, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &right->map_token, &right->kaddr,
+ &right->map_start, &right->map_len,
+ KM_USER1);
}
+
+ ioff = btrfs_item_offset(right, item);
+ btrfs_set_item_offset(right, item, ioff + rt_data_off);
+ }
+
+ if (right->map_token) {
+ unmap_extent_buffer(right, right->map_token, KM_USER1);
+ right->map_token = NULL;
+ }
+
+ btrfs_set_header_nritems(l, mid);
+ ret = 0;
+ btrfs_item_key(right, &disk_key, 0);
+ wret = insert_ptr(trans, root, path, &disk_key, right->start,
+ path->slots[1] + 1, 1);
+ if (wret)
+ ret = wret;
+
+ btrfs_mark_buffer_dirty(right);
+ btrfs_mark_buffer_dirty(l);
+ BUG_ON(path->slots[0] != slot);
+
+ ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+ BUG_ON(ret);
+
+ if (mid <= slot) {
+ btrfs_tree_unlock(path->nodes[0]);
+ free_extent_buffer(path->nodes[0]);
+ path->nodes[0] = right;
+ path->slots[0] -= mid;
+ path->slots[1] += 1;
+ } else {
+ btrfs_tree_unlock(right);
+ free_extent_buffer(right);
+ }
+
+ BUG_ON(path->slots[0] < 0);
+
+ return ret;
+}
+
+/*
+ * split the path's leaf in two, making sure there is at least data_size
+ * available for the resulting leaf level of the path.
+ *
+ * returns 0 if all went well and < 0 on failure.
+ */
+static noinline int split_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_key *ins_key,
+ struct btrfs_path *path, int data_size,
+ int extend)
+{
+ struct extent_buffer *l;
+ u32 nritems;
+ int mid;
+ int slot;
+ struct extent_buffer *right;
+ int ret = 0;
+ int wret;
+ int double_split;
+ int num_doubles = 0;
+
+ /* first try to make some room by pushing left and right */
+ if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY &&
+ !trans->transaction->delayed_refs.flushing) {
+ wret = push_leaf_right(trans, root, path, data_size, 0);
+ if (wret < 0)
+ return wret;
if (wret) {
wret = push_leaf_left(trans, root, path, data_size, 0);
if (wret < 0)
l = path->nodes[0];
/* did the pushes work? */
- if (btrfs_leaf_free_space(root, l) >= space_needed)
+ if (btrfs_leaf_free_space(root, l) >= data_size)
return 0;
}
l = path->nodes[0];
slot = path->slots[0];
nritems = btrfs_header_nritems(l);
- mid = (nritems + 1)/ 2;
+ mid = (nritems + 1) / 2;
right = btrfs_alloc_free_block(trans, root, root->leafsize,
path->nodes[1]->start,
write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
(unsigned long)btrfs_header_chunk_tree_uuid(right),
BTRFS_UUID_SIZE);
+
if (mid <= slot) {
if (nritems == 1 ||
- leaf_space_used(l, mid, nritems - mid) + space_needed >
+ leaf_space_used(l, mid, nritems - mid) + data_size >
BTRFS_LEAF_DATA_SIZE(root)) {
if (slot >= nritems) {
+ struct btrfs_disk_key disk_key;
+
btrfs_cpu_key_to_disk(&disk_key, ins_key);
btrfs_set_header_nritems(right, 0);
wret = insert_ptr(trans, root, path,
mid = slot;
if (mid != nritems &&
leaf_space_used(l, mid, nritems - mid) +
- space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
+ data_size > BTRFS_LEAF_DATA_SIZE(root)) {
double_split = 1;
}
}
} else {
- if (leaf_space_used(l, 0, mid + 1) + space_needed >
+ if (leaf_space_used(l, 0, mid) + data_size >
BTRFS_LEAF_DATA_SIZE(root)) {
- if (!extend && slot == 0) {
+ if (!extend && data_size && slot == 0) {
+ struct btrfs_disk_key disk_key;
+
btrfs_cpu_key_to_disk(&disk_key, ins_key);
btrfs_set_header_nritems(right, 0);
wret = insert_ptr(trans, root, path,
path->slots[0] = 0;
if (path->slots[1] == 0) {
wret = fixup_low_keys(trans, root,
- path, &disk_key, 1);
+ path, &disk_key, 1);
if (wret)
ret = wret;
}
btrfs_mark_buffer_dirty(right);
return ret;
- } else if (extend && slot == 0) {
+ } else if ((extend || !data_size) && slot == 0) {
mid = 1;
} else {
mid = slot;
if (mid != nritems &&
leaf_space_used(l, mid, nritems - mid) +
- space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
+ data_size > BTRFS_LEAF_DATA_SIZE(root)) {
double_split = 1;
}
}
}
}
- nritems = nritems - mid;
- btrfs_set_header_nritems(right, nritems);
- data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
- copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
- btrfs_item_nr_offset(mid),
- nritems * sizeof(struct btrfs_item));
+ ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
+ BUG_ON(ret);
- copy_extent_buffer(right, l,
- btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
- data_copy_size, btrfs_leaf_data(l) +
- leaf_data_end(root, l), data_copy_size);
+ if (double_split) {
+ BUG_ON(num_doubles != 0);
+ num_doubles++;
+ goto again;
+ }
- rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
- btrfs_item_end_nr(l, mid);
+ return ret;
+}
- for (i = 0; i < nritems; i++) {
- struct btrfs_item *item = btrfs_item_nr(right, i);
- u32 ioff;
+/*
+ * This function splits a single item into two items,
+ * giving 'new_key' to the new item and splitting the
+ * old one at split_offset (from the start of the item).
+ *
+ * The path may be released by this operation. After
+ * the split, the path is pointing to the old item. The
+ * new item is going to be in the same node as the old one.
+ *
+ * Note, the item being split must be smaller enough to live alone on
+ * a tree block with room for one extra struct btrfs_item
+ *
+ * This allows us to split the item in place, keeping a lock on the
+ * leaf the entire time.
+ */
+int btrfs_split_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *new_key,
+ unsigned long split_offset)
+{
+ u32 item_size;
+ struct extent_buffer *leaf;
+ struct btrfs_key orig_key;
+ struct btrfs_item *item;
+ struct btrfs_item *new_item;
+ int ret = 0;
+ int slot;
+ u32 nritems;
+ u32 orig_offset;
+ struct btrfs_disk_key disk_key;
+ char *buf;
- if (!right->map_token) {
- map_extent_buffer(right, (unsigned long)item,
- sizeof(struct btrfs_item),
- &right->map_token, &right->kaddr,
- &right->map_start, &right->map_len,
- KM_USER1);
- }
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
+ if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
+ goto split;
- ioff = btrfs_item_offset(right, item);
- btrfs_set_item_offset(right, item, ioff + rt_data_off);
- }
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ btrfs_release_path(root, path);
- if (right->map_token) {
- unmap_extent_buffer(right, right->map_token, KM_USER1);
- right->map_token = NULL;
- }
+ path->search_for_split = 1;
+ path->keep_locks = 1;
- btrfs_set_header_nritems(l, mid);
- ret = 0;
- btrfs_item_key(right, &disk_key, 0);
- wret = insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1);
- if (wret)
- ret = wret;
+ ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
+ path->search_for_split = 0;
- btrfs_mark_buffer_dirty(right);
- btrfs_mark_buffer_dirty(l);
- BUG_ON(path->slots[0] != slot);
+ /* if our item isn't there or got smaller, return now */
+ if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
+ path->slots[0])) {
+ path->keep_locks = 0;
+ return -EAGAIN;
+ }
- ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+ btrfs_set_path_blocking(path);
+ ret = split_leaf(trans, root, &orig_key, path,
+ sizeof(struct btrfs_item), 1);
+ path->keep_locks = 0;
BUG_ON(ret);
- if (mid <= slot) {
- btrfs_tree_unlock(path->nodes[0]);
- free_extent_buffer(path->nodes[0]);
- path->nodes[0] = right;
- path->slots[0] -= mid;
- path->slots[1] += 1;
- } else {
- btrfs_tree_unlock(right);
- free_extent_buffer(right);
+ btrfs_unlock_up_safe(path, 1);
+ leaf = path->nodes[0];
+ BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
+
+split:
+ /*
+ * make sure any changes to the path from split_leaf leave it
+ * in a blocking state
+ */
+ btrfs_set_path_blocking(path);
+
+ item = btrfs_item_nr(leaf, path->slots[0]);
+ orig_offset = btrfs_item_offset(leaf, item);
+ item_size = btrfs_item_size(leaf, item);
+
+ buf = kmalloc(item_size, GFP_NOFS);
+ read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
+ path->slots[0]), item_size);
+ slot = path->slots[0] + 1;
+ leaf = path->nodes[0];
+
+ nritems = btrfs_header_nritems(leaf);
+
+ if (slot != nritems) {
+ /* shift the items */
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
+ btrfs_item_nr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_item));
+
}
- BUG_ON(path->slots[0] < 0);
+ btrfs_cpu_key_to_disk(&disk_key, new_key);
+ btrfs_set_item_key(leaf, &disk_key, slot);
- if (double_split) {
- BUG_ON(num_doubles != 0);
- num_doubles++;
- goto again;
+ new_item = btrfs_item_nr(leaf, slot);
+
+ btrfs_set_item_offset(leaf, new_item, orig_offset);
+ btrfs_set_item_size(leaf, new_item, item_size - split_offset);
+
+ btrfs_set_item_offset(leaf, item,
+ orig_offset + item_size - split_offset);
+ btrfs_set_item_size(leaf, item, split_offset);
+
+ btrfs_set_header_nritems(leaf, nritems + 1);
+
+ /* write the data for the start of the original item */
+ write_extent_buffer(leaf, buf,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ split_offset);
+
+ /* write the data for the new item */
+ write_extent_buffer(leaf, buf + split_offset,
+ btrfs_item_ptr_offset(leaf, slot),
+ item_size - split_offset);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
}
+ kfree(buf);
return ret;
}
+/*
+ * make the item pointed to by the path smaller. new_size indicates
+ * how small to make it, and from_end tells us if we just chop bytes
+ * off the end of the item or if we shift the item to chop bytes off
+ * the front.
+ */
int btrfs_truncate_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
BTRFS_FILE_EXTENT_INLINE) {
ptr = btrfs_item_ptr_offset(leaf, slot);
memmove_extent_buffer(leaf, ptr,
- (unsigned long)fi,
- offsetof(struct btrfs_file_extent_item,
+ (unsigned long)fi,
+ offsetof(struct btrfs_file_extent_item,
disk_bytenr));
}
}
return ret;
}
+/*
+ * make the item pointed to by the path bigger, data_size is the new size.
+ */
int btrfs_extend_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
u32 data_size)
BUG_ON(slot < 0);
if (slot >= nritems) {
btrfs_print_leaf(root, leaf);
- printk("slot %d too large, nritems %d\n", slot, nritems);
+ printk(KERN_CRIT "slot %d too large, nritems %d\n",
+ slot, nritems);
BUG_ON(1);
}
}
/*
- * Given a key and some data, insert an item into the tree.
+ * Given a key and some data, insert items into the tree.
* This does all the path init required, making room in the tree if needed.
+ * Returns the number of keys that were inserted.
*/
-int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *cpu_key, u32 *data_size,
struct btrfs_item *item;
int ret = 0;
int slot;
- int slot_orig;
int i;
u32 nritems;
- u32 total_size = 0;
u32 total_data = 0;
+ u32 total_size = 0;
unsigned int data_end;
struct btrfs_disk_key disk_key;
+ struct btrfs_key found_key;
for (i = 0; i < nr; i++) {
+ if (total_size + data_size[i] + sizeof(struct btrfs_item) >
+ BTRFS_LEAF_DATA_SIZE(root)) {
+ break;
+ nr = i;
+ }
total_data += data_size[i];
+ total_size += data_size[i] + sizeof(struct btrfs_item);
}
+ BUG_ON(nr == 0);
- total_size = total_data + (nr * sizeof(struct btrfs_item));
ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
if (ret == 0)
return -EEXIST;
if (ret < 0)
goto out;
- slot_orig = path->slots[0];
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
data_end = leaf_data_end(root, leaf);
if (btrfs_leaf_free_space(root, leaf) < total_size) {
- btrfs_print_leaf(root, leaf);
- printk("not enough freespace need %u have %d\n",
- total_size, btrfs_leaf_free_space(root, leaf));
- BUG();
+ for (i = nr; i >= 0; i--) {
+ total_data -= data_size[i];
+ total_size -= data_size[i] + sizeof(struct btrfs_item);
+ if (total_size < btrfs_leaf_free_space(root, leaf))
+ break;
+ }
+ nr = i;
}
slot = path->slots[0];
if (slot != nritems) {
unsigned int old_data = btrfs_item_end_nr(leaf, slot);
+ item = btrfs_item_nr(leaf, slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ /* figure out how many keys we can insert in here */
+ total_data = data_size[0];
+ for (i = 1; i < nr; i++) {
+ if (comp_cpu_keys(&found_key, cpu_key + i) <= 0)
+ break;
+ total_data += data_size[i];
+ }
+ nr = i;
+
if (old_data < data_end) {
btrfs_print_leaf(root, leaf);
- printk("slot %d old_data %d data_end %d\n",
+ printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
slot, old_data, data_end);
BUG_ON(1);
}
data_end - total_data, btrfs_leaf_data(leaf) +
data_end, old_data - data_end);
data_end = old_data;
+ } else {
+ /*
+ * this sucks but it has to be done, if we are inserting at
+ * the end of the leaf only insert 1 of the items, since we
+ * have no way of knowing whats on the next leaf and we'd have
+ * to drop our current locks to figure it out
+ */
+ nr = 1;
}
/* setup the item for the new data */
BUG();
}
out:
+ if (!ret)
+ ret = nr;
+ return ret;
+}
+
+/*
+ * this is a helper for btrfs_insert_empty_items, the main goal here is
+ * to save stack depth by doing the bulk of the work in a function
+ * that doesn't call btrfs_search_slot
+ */
+static noinline_for_stack int
+setup_items_for_insert(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ u32 total_data, u32 total_size, int nr)
+{
+ struct btrfs_item *item;
+ int i;
+ u32 nritems;
+ unsigned int data_end;
+ struct btrfs_disk_key disk_key;
+ int ret;
+ struct extent_buffer *leaf;
+ int slot;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+
+ nritems = btrfs_header_nritems(leaf);
+ data_end = leaf_data_end(root, leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < total_size) {
+ btrfs_print_leaf(root, leaf);
+ printk(KERN_CRIT "not enough freespace need %u have %d\n",
+ total_size, btrfs_leaf_free_space(root, leaf));
+ BUG();
+ }
+
+ if (slot != nritems) {
+ unsigned int old_data = btrfs_item_end_nr(leaf, slot);
+
+ if (old_data < data_end) {
+ btrfs_print_leaf(root, leaf);
+ printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
+ slot, old_data, data_end);
+ BUG_ON(1);
+ }
+ /*
+ * item0..itemN ... dataN.offset..dataN.size .. data0.size
+ */
+ /* first correct the data pointers */
+ WARN_ON(leaf->map_token);
+ for (i = slot; i < nritems; i++) {
+ u32 ioff;
+
+ item = btrfs_item_nr(leaf, i);
+ if (!leaf->map_token) {
+ map_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+ }
+
+ ioff = btrfs_item_offset(leaf, item);
+ btrfs_set_item_offset(leaf, item, ioff - total_data);
+ }
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
+
+ /* shift the items */
+ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
+ btrfs_item_nr_offset(slot),
+ (nritems - slot) * sizeof(struct btrfs_item));
+
+ /* shift the data */
+ memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
+ data_end - total_data, btrfs_leaf_data(leaf) +
+ data_end, old_data - data_end);
+ data_end = old_data;
+ }
+
+ /* setup the item for the new data */
+ for (i = 0; i < nr; i++) {
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
+ btrfs_set_item_key(leaf, &disk_key, slot + i);
+ item = btrfs_item_nr(leaf, slot + i);
+ btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+ data_end -= data_size[i];
+ btrfs_set_item_size(leaf, item, data_size[i]);
+ }
+
+ btrfs_set_header_nritems(leaf, nritems + nr);
+
+ ret = 0;
+ if (slot == 0) {
+ struct btrfs_disk_key disk_key;
+ btrfs_cpu_key_to_disk(&disk_key, cpu_key);
+ ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+ }
+ btrfs_unlock_up_safe(path, 1);
+ btrfs_mark_buffer_dirty(leaf);
+
+ if (btrfs_leaf_free_space(root, leaf) < 0) {
+ btrfs_print_leaf(root, leaf);
+ BUG();
+ }
+ return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_key *cpu_key, u32 *data_size,
+ int nr)
+{
+ struct extent_buffer *leaf;
+ int ret = 0;
+ int slot;
+ int i;
+ u32 total_size = 0;
+ u32 total_data = 0;
+
+ for (i = 0; i < nr; i++)
+ total_data += data_size[i];
+
+ total_size = total_data + (nr * sizeof(struct btrfs_item));
+ ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+ if (ret == 0)
+ return -EEXIST;
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ BUG_ON(slot < 0);
+
+ ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
+ total_data, total_size, nr);
+
+out:
return ret;
}
/*
* delete the pointer from a given node.
*
- * If the delete empties a node, the node is removed from the tree,
- * continuing all the way the root if required. The root is converted into
- * a leaf if all the nodes are emptied.
+ * the tree should have been previously balanced so the deletion does not
+ * empty a node.
*/
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot)
int wret;
nritems = btrfs_header_nritems(parent);
- if (slot != nritems -1) {
+ if (slot != nritems - 1) {
memmove_extent_buffer(parent,
btrfs_node_key_ptr_offset(slot),
btrfs_node_key_ptr_offset(slot + 1),
}
/*
+ * a helper function to delete the leaf pointed to by path->slots[1] and
+ * path->nodes[1]. bytenr is the node block pointer, but since the callers
+ * already know it, it is faster to have them pass it down than to
+ * read it out of the node again.
+ *
+ * This deletes the pointer in path->nodes[1] and frees the leaf
+ * block extent. zero is returned if it all worked out, < 0 otherwise.
+ *
+ * The path must have already been setup for deleting the leaf, including
+ * all the proper balancing. path->nodes[1] must be locked.
+ */
+noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 bytenr)
+{
+ int ret;
+ u64 root_gen = btrfs_header_generation(path->nodes[1]);
+ u64 parent_start = path->nodes[1]->start;
+ u64 parent_owner = btrfs_header_owner(path->nodes[1]);
+
+ ret = del_ptr(trans, root, path, 1, path->slots[1]);
+ if (ret)
+ return ret;
+
+ /*
+ * btrfs_free_extent is expensive, we want to make sure we
+ * aren't holding any locks when we call it
+ */
+ btrfs_unlock_up_safe(path, 0);
+
+ ret = btrfs_free_extent(trans, root, bytenr,
+ btrfs_level_size(root, 0),
+ parent_start, parent_owner,
+ root_gen, 0, 1);
+ return ret;
+}
+/*
* delete the item at the leaf level in path. If that empties
* the leaf, remove it from the tree
*/
if (leaf == root->node) {
btrfs_set_header_level(leaf, 0);
} else {
- u64 root_gen = btrfs_header_generation(path->nodes[1]);
- wret = del_ptr(trans, root, path, 1, path->slots[1]);
- if (wret)
- ret = wret;
- wret = btrfs_free_extent(trans, root,
- leaf->start, leaf->len,
- path->nodes[1]->start,
- btrfs_header_owner(path->nodes[1]),
- root_gen, 0, 0, 1);
- if (wret)
- ret = wret;
+ ret = btrfs_del_leaf(trans, root, path, leaf->start);
+ BUG_ON(ret);
}
} else {
int used = leaf_space_used(leaf, 0, nritems);
}
/* delete the leaf if it is mostly empty */
- if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
+ if (used < BTRFS_LEAF_DATA_SIZE(root) / 4 &&
+ !trans->transaction->delayed_refs.flushing) {
/* push_leaf_left fixes the path.
* make sure the path still points to our leaf
* for possible call to del_ptr below
slot = path->slots[1];
extent_buffer_get(leaf);
+ btrfs_set_path_blocking(path);
wret = push_leaf_left(trans, root, path, 1, 1);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
}
if (btrfs_header_nritems(leaf) == 0) {
- u64 root_gen;
- u64 bytenr = leaf->start;
- u32 blocksize = leaf->len;
-
- root_gen = btrfs_header_generation(
- path->nodes[1]);
-
- wret = del_ptr(trans, root, path, 1, slot);
- if (wret)
- ret = wret;
-
+ path->slots[1] = slot;
+ ret = btrfs_del_leaf(trans, root, path,
+ leaf->start);
+ BUG_ON(ret);
free_extent_buffer(leaf);
- wret = btrfs_free_extent(trans, root, bytenr,
- blocksize, path->nodes[1]->start,
- btrfs_header_owner(path->nodes[1]),
- root_gen, 0, 0, 1);
- if (wret)
- ret = wret;
} else {
/* if we're still in the path, make sure
* we're dirty. Otherwise, one of the
* search the tree again to find a leaf with lesser keys
* returns 0 if it found something or 1 if there are no lesser leaves.
* returns < 0 on io errors.
+ *
+ * This may release the path, and so you may lose any locks held at the
+ * time you call it.
*/
int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
{
/*
* A helper function to walk down the tree starting at min_key, and looking
* for nodes or leaves that are either in cache or have a minimum
- * transaction id. This is used by the btree defrag code, but could
- * also be used to search for blocks that have changed since a given
- * transaction id.
+ * transaction id. This is used by the btree defrag code, and tree logging
*
* This does not cow, but it does stuff the starting key it finds back
* into min_key, so you can call btrfs_search_slot with cow=1 on the
* This honors path->lowest_level to prevent descent past a given level
* of the tree.
*
+ * min_trans indicates the oldest transaction that you are interested
+ * in walking through. Any nodes or leaves older than min_trans are
+ * skipped over (without reading them).
+ *
* returns zero if something useful was found, < 0 on error and 1 if there
* was nothing in the tree that matched the search criteria.
*/
int level;
int ret = 1;
+ WARN_ON(!path->keep_locks);
again:
cur = btrfs_lock_root_node(root);
level = btrfs_header_level(cur);
ret = 1;
goto out;
}
- while(1) {
+ while (1) {
nritems = btrfs_header_nritems(cur);
level = btrfs_header_level(cur);
sret = bin_search(cur, min_key, level, &slot);
- /* at level = 0, we're done, setup the path and exit */
- if (level == 0) {
+ /* at the lowest level, we're done, setup the path and exit */
+ if (level == path->lowest_level) {
if (slot >= nritems)
goto find_next_key;
ret = 0;
* min_trans parameters. If it isn't in cache or is too
* old, skip to the next one.
*/
- while(slot < nritems) {
+ while (slot < nritems) {
u64 blockptr;
u64 gen;
struct extent_buffer *tmp;
*/
if (slot >= nritems) {
path->slots[level] = slot;
+ btrfs_set_path_blocking(path);
sret = btrfs_find_next_key(root, path, min_key, level,
cache_only, min_trans);
if (sret == 0) {
unlock_up(path, level, 1);
goto out;
}
+ btrfs_set_path_blocking(path);
cur = read_node_slot(root, cur, slot);
btrfs_tree_lock(cur);
+
path->locks[level - 1] = 1;
path->nodes[level - 1] = cur;
unlock_up(path, level, 1);
+ btrfs_clear_path_blocking(path, NULL);
}
out:
if (ret == 0)
memcpy(min_key, &found_key, sizeof(found_key));
+ btrfs_set_path_blocking(path);
return ret;
}
int slot;
struct extent_buffer *c;
- while(level < BTRFS_MAX_LEVEL) {
+ WARN_ON(!path->keep_locks);
+ while (level < BTRFS_MAX_LEVEL) {
if (!path->nodes[level])
return 1;
next:
if (slot >= btrfs_header_nritems(c)) {
level++;
- if (level == BTRFS_MAX_LEVEL) {
+ if (level == BTRFS_MAX_LEVEL)
return 1;
- }
continue;
}
if (level == 0)
int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
{
int slot;
- int level = 1;
+ int level;
struct extent_buffer *c;
- struct extent_buffer *next = NULL;
+ struct extent_buffer *next;
struct btrfs_key key;
u32 nritems;
int ret;
+ int old_spinning = path->leave_spinning;
+ int force_blocking = 0;
nritems = btrfs_header_nritems(path->nodes[0]);
- if (nritems == 0) {
+ if (nritems == 0)
return 1;
- }
- btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+ /*
+ * we take the blocks in an order that upsets lockdep. Using
+ * blocking mode is the only way around it.
+ */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ force_blocking = 1;
+#endif
+ btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+again:
+ level = 1;
+ next = NULL;
btrfs_release_path(root, path);
+
path->keep_locks = 1;
+
+ if (!force_blocking)
+ path->leave_spinning = 1;
+
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
path->keep_locks = 0;
*/
if (nritems > 0 && path->slots[0] < nritems - 1) {
path->slots[0]++;
+ ret = 0;
goto done;
}
- while(level < BTRFS_MAX_LEVEL) {
- if (!path->nodes[level])
- return 1;
+ while (level < BTRFS_MAX_LEVEL) {
+ if (!path->nodes[level]) {
+ ret = 1;
+ goto done;
+ }
slot = path->slots[level] + 1;
c = path->nodes[level];
if (slot >= btrfs_header_nritems(c)) {
level++;
if (level == BTRFS_MAX_LEVEL) {
- return 1;
+ ret = 1;
+ goto done;
}
continue;
}
free_extent_buffer(next);
}
- if (level == 1 && (path->locks[1] || path->skip_locking) &&
- path->reada)
- reada_for_search(root, path, level, slot, 0);
+ next = c;
+ ret = read_block_for_search(NULL, root, path, &next, level,
+ slot, &key);
+ if (ret == -EAGAIN)
+ goto again;
- next = read_node_slot(root, c, slot);
if (!path->skip_locking) {
- WARN_ON(!btrfs_tree_locked(c));
- btrfs_tree_lock(next);
+ ret = btrfs_try_spin_lock(next);
+ if (!ret) {
+ btrfs_set_path_blocking(path);
+ btrfs_tree_lock(next);
+ if (!force_blocking)
+ btrfs_clear_path_blocking(path, next);
+ }
+ if (force_blocking)
+ btrfs_set_lock_blocking(next);
}
break;
}
path->slots[level] = slot;
- while(1) {
+ while (1) {
level--;
c = path->nodes[level];
if (path->locks[level])
btrfs_tree_unlock(c);
+
free_extent_buffer(c);
path->nodes[level] = next;
path->slots[level] = 0;
if (!path->skip_locking)
path->locks[level] = 1;
+
if (!level)
break;
- if (level == 1 && path->locks[1] && path->reada)
- reada_for_search(root, path, level, slot, 0);
- next = read_node_slot(root, next, 0);
+
+ ret = read_block_for_search(NULL, root, path, &next, level,
+ 0, &key);
+ if (ret == -EAGAIN)
+ goto again;
+
if (!path->skip_locking) {
- WARN_ON(!btrfs_tree_locked(path->nodes[level]));
- btrfs_tree_lock(next);
+ btrfs_assert_tree_locked(path->nodes[level]);
+ ret = btrfs_try_spin_lock(next);
+ if (!ret) {
+ btrfs_set_path_blocking(path);
+ btrfs_tree_lock(next);
+ if (!force_blocking)
+ btrfs_clear_path_blocking(path, next);
+ }
+ if (force_blocking)
+ btrfs_set_lock_blocking(next);
}
}
+ ret = 0;
done:
unlock_up(path, 0, 1);
- return 0;
+ path->leave_spinning = old_spinning;
+ if (!old_spinning)
+ btrfs_set_path_blocking(path);
+
+ return ret;
}
/*
u32 nritems;
int ret;
- while(1) {
+ while (1) {
if (path->slots[0] == 0) {
+ btrfs_set_path_blocking(path);
ret = btrfs_prev_leaf(root, path);
if (ret != 0)
return ret;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff