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authorChris Mason <chris.mason@oracle.com>2007-11-20 10:47:25 -0500
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:03:58 -0400
commit3e9fd94ff0028a044d55690eb0a801fd1472e3c6 (patch)
treedb90bb2cb783763b144d2b4ff87ad3c41113495f /fs/btrfs/extent_map.c
parent2f4cbe6442d3be7b5e4cf1607a5ab33995fe2d25 (diff)
Btrfs: Avoid fragmentation from parallel delalloc filling
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c83
1 files changed, 49 insertions, 34 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index f91f28efdb5..7fd4eb7a8f0 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1033,11 +1033,11 @@ out:
EXPORT_SYMBOL(find_first_extent_bit);
u64 find_lock_delalloc_range(struct extent_map_tree *tree,
- u64 start, u64 lock_start, u64 *end, u64 max_bytes)
+ u64 *start, u64 *end, u64 max_bytes)
{
struct rb_node *node;
struct extent_state *state;
- u64 cur_start = start;
+ u64 cur_start = *start;
u64 found = 0;
u64 total_bytes = 0;
@@ -1054,27 +1054,43 @@ search_again:
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
- if (state->start != cur_start) {
+ if (found && state->start != cur_start) {
goto out;
}
if (!(state->state & EXTENT_DELALLOC)) {
goto out;
}
- if (state->start >= lock_start) {
- if (state->state & EXTENT_LOCKED) {
- DEFINE_WAIT(wait);
- atomic_inc(&state->refs);
- prepare_to_wait(&state->wq, &wait,
- TASK_UNINTERRUPTIBLE);
- write_unlock_irq(&tree->lock);
- schedule();
- write_lock_irq(&tree->lock);
- finish_wait(&state->wq, &wait);
- free_extent_state(state);
- goto search_again;
+ if (!found) {
+ struct extent_state *prev_state;
+ struct rb_node *prev_node = node;
+ while(1) {
+ prev_node = rb_prev(prev_node);
+ if (!prev_node)
+ break;
+ prev_state = rb_entry(prev_node,
+ struct extent_state,
+ rb_node);
+ if (!(prev_state->state & EXTENT_DELALLOC))
+ break;
+ state = prev_state;
+ node = prev_node;
}
- state->state |= EXTENT_LOCKED;
}
+ if (state->state & EXTENT_LOCKED) {
+ DEFINE_WAIT(wait);
+ atomic_inc(&state->refs);
+ prepare_to_wait(&state->wq, &wait,
+ TASK_UNINTERRUPTIBLE);
+ write_unlock_irq(&tree->lock);
+ schedule();
+ write_lock_irq(&tree->lock);
+ finish_wait(&state->wq, &wait);
+ free_extent_state(state);
+ goto search_again;
+ }
+ state->state |= EXTENT_LOCKED;
+ if (!found)
+ *start = state->start;
found++;
*end = state->end;
cur_start = state->end + 1;
@@ -1695,6 +1711,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
struct extent_page_data *epd = data;
struct extent_map_tree *tree = epd->tree;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
+ u64 delalloc_start;
u64 page_end = start + PAGE_CACHE_SIZE - 1;
u64 end;
u64 cur = start;
@@ -1729,25 +1746,23 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
set_page_extent_mapped(page);
- lock_extent(tree, start, page_end, GFP_NOFS);
- nr_delalloc = find_lock_delalloc_range(tree, start, page_end + 1,
- &delalloc_end,
- 128 * 1024 * 1024);
- if (nr_delalloc) {
- tree->ops->fill_delalloc(inode, start, delalloc_end);
- if (delalloc_end >= page_end + 1) {
- clear_extent_bit(tree, page_end + 1, delalloc_end,
- EXTENT_LOCKED | EXTENT_DELALLOC,
- 1, 0, GFP_NOFS);
- }
- clear_extent_bit(tree, start, page_end, EXTENT_DELALLOC,
- 0, 0, GFP_NOFS);
- if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
- printk("found delalloc bits after clear extent_bit\n");
- }
- } else if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {
- printk("found delalloc bits after find_delalloc_range returns 0\n");
+ delalloc_start = start;
+ delalloc_end = 0;
+ while(delalloc_end < page_end) {
+ nr_delalloc = find_lock_delalloc_range(tree, &delalloc_start,
+ &delalloc_end,
+ 128 * 1024 * 1024);
+ if (nr_delalloc <= 0)
+ break;
+ tree->ops->fill_delalloc(inode, delalloc_start,
+ delalloc_end);
+ clear_extent_bit(tree, delalloc_start,
+ delalloc_end,
+ EXTENT_LOCKED | EXTENT_DELALLOC,
+ 1, 0, GFP_NOFS);
+ delalloc_start = delalloc_end + 1;
}
+ lock_extent(tree, start, page_end, GFP_NOFS);
end = page_end;
if (test_range_bit(tree, start, page_end, EXTENT_DELALLOC, 0)) {