Btrfs: use a cached state for extent state operations during delalloc
This changes the btrfs code to find delalloc ranges in the extent state
tree to use the new state caching code from set/test bit. It reduces
one of the biggest causes of rbtree searches in the writeback path.
test_range_bit is also modified to take the cached state as a starting
point while searching.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 04fafc3..c9a438d 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -720,6 +720,13 @@
}
spin_lock(&tree->lock);
+ if (cached_state && *cached_state) {
+ state = *cached_state;
+ if (state->start == start && state->tree) {
+ node = &state->rb_node;
+ goto hit_next;
+ }
+ }
/*
* this search will find all the extents that end after
* our range starts.
@@ -1286,6 +1293,7 @@
u64 delalloc_start;
u64 delalloc_end;
u64 found;
+ struct extent_state *cached_state = NULL;
int ret;
int loops = 0;
@@ -1323,6 +1331,7 @@
/* some of the pages are gone, lets avoid looping by
* shortening the size of the delalloc range we're searching
*/
+ free_extent_state(cached_state);
if (!loops) {
unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
max_bytes = PAGE_CACHE_SIZE - offset;
@@ -1336,18 +1345,21 @@
BUG_ON(ret);
/* step three, lock the state bits for the whole range */
- lock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
+ lock_extent_bits(tree, delalloc_start, delalloc_end,
+ 0, &cached_state, GFP_NOFS);
/* then test to make sure it is all still delalloc */
ret = test_range_bit(tree, delalloc_start, delalloc_end,
- EXTENT_DELALLOC, 1);
+ EXTENT_DELALLOC, 1, cached_state);
if (!ret) {
- unlock_extent(tree, delalloc_start, delalloc_end, GFP_NOFS);
+ unlock_extent_cached(tree, delalloc_start, delalloc_end,
+ &cached_state, GFP_NOFS);
__unlock_for_delalloc(inode, locked_page,
delalloc_start, delalloc_end);
cond_resched();
goto again;
}
+ free_extent_state(cached_state);
*start = delalloc_start;
*end = delalloc_end;
out_failed:
@@ -1530,14 +1542,17 @@
* range is found set.
*/
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
- int bits, int filled)
+ int bits, int filled, struct extent_state *cached)
{
struct extent_state *state = NULL;
struct rb_node *node;
int bitset = 0;
spin_lock(&tree->lock);
- node = tree_search(tree, start);
+ if (cached && cached->tree && cached->start == start)
+ node = &cached->rb_node;
+ else
+ node = tree_search(tree, start);
while (node && start <= end) {
state = rb_entry(node, struct extent_state, rb_node);
@@ -1580,7 +1595,7 @@
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
- if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1))
+ if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
SetPageUptodate(page);
return 0;
}
@@ -1594,7 +1609,7 @@
{
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 end = start + PAGE_CACHE_SIZE - 1;
- if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0))
+ if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
unlock_page(page);
return 0;
}
@@ -2032,7 +2047,8 @@
continue;
}
/* the get_extent function already copied into the page */
- if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1)) {
+ if (test_range_bit(tree, cur, cur_end,
+ EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
cur = cur + iosize;
@@ -2305,7 +2321,7 @@
}
/* leave this out until we have a page_mkwrite call */
if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
- EXTENT_DIRTY, 0)) {
+ EXTENT_DIRTY, 0, NULL)) {
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2721,7 +2737,7 @@
!isnew && !PageUptodate(page) &&
(block_off_end > to || block_off_start < from) &&
!test_range_bit(tree, block_start, cur_end,
- EXTENT_UPTODATE, 1)) {
+ EXTENT_UPTODATE, 1, NULL)) {
u64 sector;
u64 extent_offset = block_start - em->start;
size_t iosize;
@@ -2776,7 +2792,7 @@
int ret = 1;
if (test_range_bit(tree, start, end,
- EXTENT_IOBITS | EXTENT_ORDERED, 0))
+ EXTENT_IOBITS | EXTENT_ORDERED, 0, NULL))
ret = 0;
else {
if ((mask & GFP_NOFS) == GFP_NOFS)
@@ -2821,7 +2837,7 @@
extent_map_end(em) - 1,
EXTENT_LOCKED | EXTENT_WRITEBACK |
EXTENT_ORDERED,
- 0)) {
+ 0, NULL)) {
remove_extent_mapping(map, em);
/* once for the rb tree */
free_extent_map(em);
@@ -3237,7 +3253,7 @@
int uptodate;
unsigned long index;
- ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1);
+ ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL);
if (ret)
return 1;
while (start <= end) {
@@ -3267,7 +3283,7 @@
return 1;
ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
- EXTENT_UPTODATE, 1);
+ EXTENT_UPTODATE, 1, NULL);
if (ret)
return ret;
@@ -3303,7 +3319,7 @@
return 0;
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
- EXTENT_UPTODATE, 1)) {
+ EXTENT_UPTODATE, 1, NULL)) {
return 0;
}
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index c8ead2b..09cd6fa 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -157,7 +157,7 @@
u64 max_bytes, unsigned long bits);
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
- int bits, int filled);
+ int bits, int filled, struct extent_state *cached_state);
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
int bits, gfp_t mask);
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e494545..3f8e93d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1376,7 +1376,7 @@
/* already ordered? We're done */
if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
- EXTENT_ORDERED, 0)) {
+ EXTENT_ORDERED, 0, NULL)) {
goto out;
}
@@ -1417,7 +1417,7 @@
int ret;
ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
- EXTENT_ORDERED, 0);
+ EXTENT_ORDERED, 0, NULL);
if (ret)
return 0;
@@ -1795,7 +1795,7 @@
return 0;
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
- test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1)) {
+ test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
GFP_NOFS);
return 0;
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index d6f0806..7f751e4 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -262,7 +262,7 @@
ret = test_range_bit(io_tree, entry->file_offset,
entry->file_offset + entry->len - 1,
- EXTENT_ORDERED, 0);
+ EXTENT_ORDERED, 0, NULL);
if (ret == 0)
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
out:
@@ -522,7 +522,7 @@
end--;
}
if (test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
- EXTENT_ORDERED | EXTENT_DELALLOC, 0)) {
+ EXTENT_ORDERED | EXTENT_DELALLOC, 0, NULL)) {
schedule_timeout(1);
goto again;
}
@@ -613,7 +613,7 @@
*/
if (test_range_bit(io_tree, disk_i_size,
ordered->file_offset + ordered->len - 1,
- EXTENT_DELALLOC, 0)) {
+ EXTENT_DELALLOC, 0, NULL)) {
goto out;
}
/*
@@ -664,7 +664,7 @@
*/
if (i_size_test > entry_end(ordered) &&
!test_range_bit(io_tree, entry_end(ordered), i_size_test - 1,
- EXTENT_DELALLOC, 0)) {
+ EXTENT_DELALLOC, 0, NULL)) {
new_i_size = min_t(u64, i_size_test, i_size_read(inode));
}
BTRFS_I(inode)->disk_i_size = new_i_size;
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 4adab90..3be16cc 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2180,7 +2180,7 @@
struct reloc_control *rc)
{
if (test_range_bit(&rc->processed_blocks, bytenr,
- bytenr + blocksize - 1, EXTENT_DIRTY, 1))
+ bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
return 1;
return 0;
}
