Btrfs: use a cached state for extent state operations during delalloc
authorChris Mason <chris.mason@oracle.com>
Wed, 2 Sep 2009 19:22:30 +0000 (15:22 -0400)
committerChris Mason <chris.mason@oracle.com>
Fri, 11 Sep 2009 17:31:07 +0000 (13:31 -0400)
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>
fs/btrfs/extent_io.c
fs/btrfs/extent_io.h
fs/btrfs/inode.c
fs/btrfs/ordered-data.c
fs/btrfs/relocation.c

index 04fafc3cffc0e20d7e0fdaa6b6317db223430d77..c9a438d374b6868c66c126fd5f84b28ecf685463 100644 (file)
@@ -720,6 +720,13 @@ again:
        }
 
        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 @@ static noinline u64 find_lock_delalloc_range(struct inode *inode,
        u64 delalloc_start;
        u64 delalloc_end;
        u64 found;
+       struct extent_state *cached_state = NULL;
        int ret;
        int loops = 0;
 
@@ -1323,6 +1331,7 @@ again:
                /* 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 @@ again:
        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 @@ out:
  * 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 @@ static int check_page_uptodate(struct extent_io_tree *tree,
 {
        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 @@ static int check_page_locked(struct extent_io_tree *tree,
 {
        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 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                        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 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                }
                /* 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 @@ int extent_prepare_write(struct extent_io_tree *tree,
                    !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 try_release_extent_state(struct extent_map_tree *map,
        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 @@ int try_release_extent_mapping(struct extent_map_tree *map,
                                            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 extent_range_uptodate(struct extent_io_tree *tree,
        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 @@ int extent_buffer_uptodate(struct extent_io_tree *tree,
                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 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
                return 0;
 
        if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
-                          EXTENT_UPTODATE, 1)) {
+                          EXTENT_UPTODATE, 1, NULL)) {
                return 0;
        }
 
index c8ead2b8c4c90ce16db40b15868e6ad7e959ef16..09cd6fa3cc86ecf2d6bdbb53e04bbe26af65b6ed 100644 (file)
@@ -157,7 +157,7 @@ u64 count_range_bits(struct extent_io_tree *tree,
                     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,
index e494545c42029e27cad43b34411dc793a8355d9c..3f8e93de298948183d5f036d3dfe24c1955aaa0f 100644 (file)
@@ -1376,7 +1376,7 @@ again:
 
        /* 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 @@ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
        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 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                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;
index d6f0806c682ff83fc11b019ac4f26d1f732acbec..7f751e462f0b88a1af8badea9478b88c510a7d29 100644 (file)
@@ -262,7 +262,7 @@ int btrfs_dec_test_ordered_pending(struct inode *inode,
 
        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 @@ again:
                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 @@ int btrfs_ordered_update_i_size(struct inode *inode,
         */
        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 @@ int btrfs_ordered_update_i_size(struct inode *inode,
         */
        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;
index 4adab903fc2bd269b17aa4c565368a6aae5c2451..3be16ccc7eea852f21c1fc94fa33b704e4a5d9aa 100644 (file)
@@ -2180,7 +2180,7 @@ static int tree_block_processed(u64 bytenr, u32 blocksize,
                                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;
 }