Btrfs: Add efficient dirty accounting to the extent_map tree
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index de05525..eef4ab5 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -210,7 +210,7 @@
{
struct extent_map_tree *tree;
tree = &BTRFS_I(mapping->host)->extent_tree;
- if (wbc->sync_mode == WB_SYNC_NONE && current_is_pdflush()) {
+ if (wbc->sync_mode == WB_SYNC_NONE) {
u64 num_dirty;
u64 start = 0;
unsigned long thresh = 96 * 1024 * 1024;
@@ -218,6 +218,11 @@
if (wbc->for_kupdate)
return 0;
+ if (current_is_pdflush()) {
+ thresh = 96 * 1024 * 1024;
+ } else {
+ thresh = 8 * 1024 * 1024;
+ }
num_dirty = count_range_bits(tree, &start, thresh, EXTENT_DIRTY);
if (num_dirty < thresh) {
return 0;
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index b6a4974..06e4377 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -42,6 +42,7 @@
struct extent_map_tree *tree;
get_extent_t *get_extent;
};
+
int __init extent_map_init(void)
{
extent_map_cache = btrfs_cache_create("extent_map",
@@ -94,6 +95,7 @@
tree->map.rb_node = NULL;
tree->state.rb_node = NULL;
tree->ops = NULL;
+ tree->dirty_bytes = 0;
rwlock_init(&tree->lock);
spin_lock_init(&tree->lru_lock);
tree->mapping = mapping;
@@ -414,6 +416,8 @@
printk("end < start %Lu %Lu\n", end, start);
WARN_ON(1);
}
+ if (bits & EXTENT_DIRTY)
+ tree->dirty_bytes += end - start + 1;
state->state |= bits;
state->start = start;
state->end = end;
@@ -476,6 +480,12 @@
int delete)
{
int ret = state->state & bits;
+
+ if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
+ u64 range = state->end - state->start + 1;
+ WARN_ON(range > tree->dirty_bytes);
+ tree->dirty_bytes -= range;
+ }
state->state &= ~bits;
if (wake)
wake_up(&state->wq);
@@ -668,6 +678,17 @@
}
EXPORT_SYMBOL(wait_extent_bit);
+static void set_state_bits(struct extent_map_tree *tree,
+ struct extent_state *state,
+ int bits)
+{
+ if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
+ u64 range = state->end - state->start + 1;
+ tree->dirty_bytes += range;
+ }
+ state->state |= bits;
+}
+
/*
* set some bits on a range in the tree. This may require allocations
* or sleeping, so the gfp mask is used to indicate what is allowed.
@@ -727,7 +748,7 @@
err = -EEXIST;
goto out;
}
- state->state |= bits;
+ set_state_bits(tree, state, bits);
start = state->end + 1;
merge_state(tree, state);
goto search_again;
@@ -762,7 +783,7 @@
if (err)
goto out;
if (state->end <= end) {
- state->state |= bits;
+ set_state_bits(tree, state, bits);
start = state->end + 1;
merge_state(tree, state);
} else {
@@ -808,7 +829,7 @@
err = split_state(tree, state, prealloc, end + 1);
BUG_ON(err == -EEXIST);
- prealloc->state |= bits;
+ set_state_bits(tree, prealloc, bits);
merge_state(tree, prealloc);
prealloc = NULL;
goto out;
@@ -1116,6 +1137,11 @@
int found = 0;
write_lock_irq(&tree->lock);
+ if (bits == EXTENT_DIRTY) {
+ *start = 0;
+ total_bytes = tree->dirty_bytes;
+ goto out;
+ }
/*
* this search will find all the extents that end after
* our range starts.
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 13c562f..2ffc0c7 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -40,6 +40,7 @@
struct rb_root map;
struct rb_root state;
struct address_space *mapping;
+ u64 dirty_bytes;
rwlock_t lock;
struct extent_map_ops *ops;
spinlock_t lru_lock;