Commit 60484cd9 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: subpage: make readahead work properly 



In readahead infrastructure, we are using a lot of hard coded PAGE_SHIFT
while we're not doing anything specific to PAGE_SIZE.

One of the most affected part is the radix tree operation of
btrfs_fs_info::reada_tree.

If using PAGE_SHIFT, subpage metadata readahead is broken and does no
help reading metadata ahead.

Fix the problem by using btrfs_fs_info::sectorsize_bits so that
readahead could work for subpage.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent d9bb77d5

fs/btrfs/reada.c

+18 −17
Original line number Diff line number Diff line
@@ -209,7 +209,7 @@ int btree_readahead_hook(struct extent_buffer *eb, int err) 
	/* find extent */

	spin_lock(&fs_info->reada_lock);

	re = radix_tree_lookup(&fs_info->reada_tree,

			       eb->start >> PAGE_SHIFT);

			       eb->start >> fs_info->sectorsize_bits);

	if (re)

		re->refcnt++;

	spin_unlock(&fs_info->reada_lock);
@@ -240,7 +240,7 @@ static struct reada_zone *reada_find_zone(struct btrfs_device *dev, u64 logical, 
	zone = NULL;

	spin_lock(&fs_info->reada_lock);

	ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,

				     logical >> PAGE_SHIFT, 1);

				     logical >> fs_info->sectorsize_bits, 1);

	if (ret == 1 && logical >= zone->start && logical <= zone->end) {

		kref_get(&zone->refcnt);

		spin_unlock(&fs_info->reada_lock);
@@ -283,13 +283,13 @@ static struct reada_zone *reada_find_zone(struct btrfs_device *dev, u64 logical, 


	spin_lock(&fs_info->reada_lock);

	ret = radix_tree_insert(&dev->reada_zones,

				(unsigned long)(zone->end >> PAGE_SHIFT),

			(unsigned long)(zone->end >> fs_info->sectorsize_bits),

			zone);



	if (ret == -EEXIST) {

		kfree(zone);

		ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,

					     logical >> PAGE_SHIFT, 1);

					logical >> fs_info->sectorsize_bits, 1);

		if (ret == 1 && logical >= zone->start && logical <= zone->end)

			kref_get(&zone->refcnt);

		else
@@ -315,7 +315,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, 
	u64 length;

	int real_stripes;

	int nzones = 0;

	unsigned long index = logical >> PAGE_SHIFT;

	unsigned long index = logical >> fs_info->sectorsize_bits;

	int dev_replace_is_ongoing;

	int have_zone = 0;
@@ -497,7 +497,7 @@ static void reada_extent_put(struct btrfs_fs_info *fs_info, 
			     struct reada_extent *re)

{

	int i;

	unsigned long index = re->logical >> PAGE_SHIFT;

	unsigned long index = re->logical >> fs_info->sectorsize_bits;



	spin_lock(&fs_info->reada_lock);

	if (--re->refcnt) {
@@ -538,11 +538,12 @@ static void reada_extent_put(struct btrfs_fs_info *fs_info, 
static void reada_zone_release(struct kref *kref)

{

	struct reada_zone *zone = container_of(kref, struct reada_zone, refcnt);

	struct btrfs_fs_info *fs_info = zone->device->fs_info;



	lockdep_assert_held(&zone->device->fs_info->reada_lock);

	lockdep_assert_held(&fs_info->reada_lock);



	radix_tree_delete(&zone->device->reada_zones,

			  zone->end >> PAGE_SHIFT);

			  zone->end >> fs_info->sectorsize_bits);



	kfree(zone);

}
@@ -593,7 +594,7 @@ static int reada_add_block(struct reada_control *rc, u64 logical, 
static void reada_peer_zones_set_lock(struct reada_zone *zone, int lock)

{

	int i;

	unsigned long index = zone->end >> PAGE_SHIFT;

	unsigned long index = zone->end >> zone->device->fs_info->sectorsize_bits;



	for (i = 0; i < zone->ndevs; ++i) {

		struct reada_zone *peer;
@@ -628,7 +629,7 @@ static int reada_pick_zone(struct btrfs_device *dev) 
					     (void **)&zone, index, 1);

		if (ret == 0)

			break;

		index = (zone->end >> PAGE_SHIFT) + 1;

		index = (zone->end >> dev->fs_info->sectorsize_bits) + 1;

		if (zone->locked) {

			if (zone->elems > top_locked_elems) {

				top_locked_elems = zone->elems;
@@ -709,7 +710,7 @@ static int reada_start_machine_dev(struct btrfs_device *dev) 
	 * plugging to speed things up

	 */

	ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re,

				     dev->reada_next >> PAGE_SHIFT, 1);

				dev->reada_next >> fs_info->sectorsize_bits, 1);

	if (ret == 0 || re->logical > dev->reada_curr_zone->end) {

		ret = reada_pick_zone(dev);

		if (!ret) {
@@ -718,7 +719,7 @@ static int reada_start_machine_dev(struct btrfs_device *dev) 
		}

		re = NULL;

		ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re,

					dev->reada_next >> PAGE_SHIFT, 1);

				dev->reada_next >> fs_info->sectorsize_bits, 1);

	}

	if (ret == 0) {

		spin_unlock(&fs_info->reada_lock);
@@ -885,7 +886,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all) 
				pr_cont(" curr off %llu",

					device->reada_next - zone->start);

			pr_cont("\n");

			index = (zone->end >> PAGE_SHIFT) + 1;

			index = (zone->end >> fs_info->sectorsize_bits) + 1;

		}

		cnt = 0;

		index = 0;
@@ -910,7 +911,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all) 
				}

			}

			pr_cont("\n");

			index = (re->logical >> PAGE_SHIFT) + 1;

			index = (re->logical >> fs_info->sectorsize_bits) + 1;

			if (++cnt > 15)

				break;

		}
@@ -926,7 +927,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all) 
		if (ret == 0)

			break;

		if (!re->scheduled) {

			index = (re->logical >> PAGE_SHIFT) + 1;

			index = (re->logical >> fs_info->sectorsize_bits) + 1;

			continue;

		}

		pr_debug("re: logical %llu size %u list empty %d scheduled %d",
@@ -942,7 +943,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all) 
			}

		}

		pr_cont("\n");

		index = (re->logical >> PAGE_SHIFT) + 1;

		index = (re->logical >> fs_info->sectorsize_bits) + 1;

	}

	spin_unlock(&fs_info->reada_lock);

}