u64 *delalloc_start_ret, u64 *delalloc_end_ret)
{
u64 len = end + 1 - start;
- struct extent_map_tree *em_tree = &inode->extent_tree;
- struct extent_map *em;
- u64 em_end;
- u64 delalloc_len;
- unsigned int outstanding_extents;
+ u64 delalloc_len = 0;
+ struct btrfs_ordered_extent *oe;
+ u64 oe_start;
+ u64 oe_end;
/*
* Search the io tree first for EXTENT_DELALLOC. If we find any, it
* means we have delalloc (dirty pages) for which writeback has not
* started yet.
*/
- spin_lock(&inode->lock);
- outstanding_extents = inode->outstanding_extents;
-
- if (*search_io_tree && inode->delalloc_bytes > 0) {
- spin_unlock(&inode->lock);
- *delalloc_start_ret = start;
- delalloc_len = count_range_bits(&inode->io_tree,
- delalloc_start_ret, end,
- len, EXTENT_DELALLOC, 1);
- } else {
- spin_unlock(&inode->lock);
- delalloc_len = 0;
+ if (*search_io_tree) {
+ spin_lock(&inode->lock);
+ if (inode->delalloc_bytes > 0) {
+ spin_unlock(&inode->lock);
+ *delalloc_start_ret = start;
+ delalloc_len = count_range_bits(&inode->io_tree,
+ delalloc_start_ret, end,
+ len, EXTENT_DELALLOC, 1);
+ } else {
+ spin_unlock(&inode->lock);
+ }
}
if (delalloc_len > 0) {
/* Delalloc for the whole range, nothing more to do. */
if (*delalloc_end_ret == end)
return true;
- /* Else trim our search range for extent maps. */
+ /* Else trim our search range for ordered extents. */
start = *delalloc_end_ret + 1;
len = end + 1 - start;
}
}
/*
- * No outstanding extents means we don't have any delalloc that is
- * flushing, so return the unflushed range found in the io tree (if any).
- */
- if (outstanding_extents == 0)
- return (delalloc_len > 0);
-
- /*
- * Now also check if there's any extent map in the range that does not
- * map to a hole or prealloc extent. We do this because:
+ * Now also check if there's any ordered extent in the range.
+ * We do this because:
*
* 1) When delalloc is flushed, the file range is locked, we clear the
- * EXTENT_DELALLOC bit from the io tree and create an extent map for
- * an allocated extent. So we might just have been called after
- * delalloc is flushed and before the ordered extent completes and
- * inserts the new file extent item in the subvolume's btree;
+ * EXTENT_DELALLOC bit from the io tree and create an extent map and
+ * an ordered extent for the write. So we might just have been called
+ * after delalloc is flushed and before the ordered extent completes
+ * and inserts the new file extent item in the subvolume's btree;
*
- * 2) We may have an extent map created by flushing delalloc for a
+ * 2) We may have an ordered extent created by flushing delalloc for a
* subrange that starts before the subrange we found marked with
* EXTENT_DELALLOC in the io tree.
+ *
+ * We could also use the extent map tree to find such delalloc that is
+ * being flushed, but using the ordered extents tree is more efficient
+ * because it's usually much smaller as ordered extents are removed from
+ * the tree once they complete. With the extent maps, we mau have them
+ * in the extent map tree for a very long time, and they were either
+ * created by previous writes or loaded by read operations.
*/
- read_lock(&em_tree->lock);
- em = lookup_extent_mapping(em_tree, start, len);
- if (!em) {
- read_unlock(&em_tree->lock);
+ oe = btrfs_lookup_first_ordered_range(inode, start, len);
+ if (!oe)
return (delalloc_len > 0);
- }
-
- /* extent_map_end() returns a non-inclusive end offset. */
- em_end = extent_map_end(em);
-
- /*
- * If we have a hole/prealloc extent map, check the next one if this one
- * ends before our range's end.
- */
- if ((em->block_start == EXTENT_MAP_HOLE ||
- test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) && em_end < end) {
- struct extent_map *next_em;
-
- next_em = btrfs_next_extent_map(em_tree, em);
- free_extent_map(em);
-
- /*
- * There's no next extent map or the next one starts beyond our
- * range, return the range found in the io tree (if any).
- */
- if (!next_em || next_em->start > end) {
- read_unlock(&em_tree->lock);
- free_extent_map(next_em);
- return (delalloc_len > 0);
- }
- em_end = extent_map_end(next_em);
- em = next_em;
- }
-
- read_unlock(&em_tree->lock);
+ /* The ordered extent may span beyond our search range. */
+ oe_start = max(oe->file_offset, start);
+ oe_end = min(oe->file_offset + oe->num_bytes - 1, end);
- /*
- * We have a hole or prealloc extent that ends at or beyond our range's
- * end, return the range found in the io tree (if any).
- */
- if (em->block_start == EXTENT_MAP_HOLE ||
- test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
- free_extent_map(em);
- return (delalloc_len > 0);
- }
+ btrfs_put_ordered_extent(oe);
- /*
- * We don't have any range as EXTENT_DELALLOC in the io tree, so the
- * extent map is the only subrange representing delalloc.
- */
+ /* Don't have unflushed delalloc, return the ordered extent range. */
if (delalloc_len == 0) {
- *delalloc_start_ret = em->start;
- *delalloc_end_ret = min(end, em_end - 1);
- free_extent_map(em);
+ *delalloc_start_ret = oe_start;
+ *delalloc_end_ret = oe_end;
return true;
}
/*
- * The extent map represents a delalloc range that starts before the
- * delalloc range we found in the io tree.
+ * We have both unflushed delalloc (io_tree) and an ordered extent.
+ * If the ranges are adjacent returned a combined range, otherwise
+ * return the leftmost range.
*/
- if (em->start < *delalloc_start_ret) {
- *delalloc_start_ret = em->start;
- /*
- * If the ranges are adjacent, return a combined range.
- * Otherwise return the extent map's range.
- */
- if (em_end < *delalloc_start_ret)
- *delalloc_end_ret = min(end, em_end - 1);
-
- free_extent_map(em);
- return true;
+ if (oe_start < *delalloc_start_ret) {
+ if (oe_end < *delalloc_start_ret)
+ *delalloc_end_ret = oe_end;
+ *delalloc_start_ret = oe_start;
+ } else if (*delalloc_end_ret + 1 == oe_start) {
+ *delalloc_end_ret = oe_end;
}
- /*
- * The extent map starts after the delalloc range we found in the io
- * tree. If it's adjacent, return a combined range, otherwise return
- * the range found in the io tree.
- */
- if (*delalloc_end_ret + 1 == em->start)
- *delalloc_end_ret = min(end, em_end - 1);
-
- free_extent_map(em);
return true;
}
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