summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2007-11-26 16:34:41 -0800
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:03:58 -0400
commit793955bca66c99defdffc857ae6eb7e8431d6bbe (patch)
tree2f8376247033fced7289038b8d82e10a6cc55f22
parent015a739c7c238768fbfa4eea8ea2ebc1a35e7bb1 (diff)
Btrfs: Limit btree writeback to prevent seeks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/disk-io.c9
-rw-r--r--fs/btrfs/extent_map.c39
-rw-r--r--fs/btrfs/extent_map.h3
3 files changed, 51 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3e16cca72b49..28e9ef8a3253 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -210,6 +210,15 @@ static int btree_writepages(struct address_space *mapping,
{
struct extent_map_tree *tree;
tree = &BTRFS_I(mapping->host)->extent_tree;
+ if (wbc->sync_mode == WB_SYNC_NONE) {
+ u64 num_dirty;
+ u64 start = 0;
+ unsigned long thresh = 96 * 1024 * 1024;
+ num_dirty = count_range_bits(tree, &start, thresh, EXTENT_DIRTY);
+ if (num_dirty < thresh) {
+ return 0;
+ }
+ }
return extent_writepages(tree, mapping, btree_get_extent, wbc);
}
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 55f272c335c6..b6a4974ecc23 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1106,6 +1106,45 @@ out:
return found;
}
+u64 count_range_bits(struct extent_map_tree *tree,
+ u64 *start, u64 max_bytes, unsigned long bits)
+{
+ struct rb_node *node;
+ struct extent_state *state;
+ u64 cur_start = *start;
+ u64 total_bytes = 0;
+ int found = 0;
+
+ write_lock_irq(&tree->lock);
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = tree_search(&tree->state, cur_start);
+ if (!node || IS_ERR(node)) {
+ goto out;
+ }
+
+ while(1) {
+ state = rb_entry(node, struct extent_state, rb_node);
+ if ((state->state & bits)) {
+ total_bytes += state->end - state->start + 1;
+ if (total_bytes >= max_bytes)
+ break;
+ if (!found) {
+ *start = state->start;
+ found = 1;
+ }
+ }
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ write_unlock_irq(&tree->lock);
+ return total_bytes;
+}
+
/*
* helper function to lock both pages and extents in the tree.
* pages must be locked first.
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 24ddc8c93461..13c562f7cb6f 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -113,6 +113,9 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
int __init extent_map_init(void);
void __exit extent_map_exit(void);
+u64 count_range_bits(struct extent_map_tree *tree,
+ u64 *start, u64 max_bytes, unsigned long bits);
+
int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
int bits, int filled);
int clear_extent_bits(struct extent_map_tree *tree, u64 start, u64 end,