btrfs: don't use btrfs_bio_wq_end_io for compressed writes

Compressed write bio completion is the only user of btrfs_bio_wq_end_io
for writes, and the use of btrfs_bio_wq_end_io is a little suboptimal
here as we only real need user context for the final completion of a
compressed_bio structure, and not every single bio completion.

Add a work_struct to struct compressed_bio instead and use that to call
finish_compressed_bio_write.  This allows to remove all handling of
write bios in the btrfs_bio_wq_end_io infrastructure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 2536754..2ea5cf5 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -398,6 +398,14 @@ static void finish_compressed_bio_write(struct compressed_bio *cb)
        kfree(cb);
 }
 
+static void btrfs_finish_compressed_write_work(struct work_struct *work)
+{
+       struct compressed_bio *cb =
+               container_of(work, struct compressed_bio, write_end_work);
+
+       finish_compressed_bio_write(cb);
+}
+
 /*
  * Do the cleanup once all the compressed pages hit the disk.  This will clear
  * writeback on the file pages and free the compressed pages.
@@ -409,29 +417,15 @@ static void end_compressed_bio_write(struct bio *bio)
 {
        struct compressed_bio *cb = bio->bi_private;
 
-       if (!dec_and_test_compressed_bio(cb, bio))
-               goto out;
-
-       btrfs_record_physical_zoned(cb->inode, cb->start, bio);
+       if (dec_and_test_compressed_bio(cb, bio)) {
+               struct btrfs_fs_info *fs_info = btrfs_sb(cb->inode->i_sb);
 
-       finish_compressed_bio_write(cb);
-out:
+               btrfs_record_physical_zoned(cb->inode, cb->start, bio);
+               queue_work(fs_info->compressed_write_workers, &cb->write_end_work);
+       }
        bio_put(bio);
 }
 
-static blk_status_t submit_compressed_bio(struct btrfs_fs_info *fs_info,
-                                         struct bio *bio, int mirror_num)
-{
-       blk_status_t ret;
-
-       ASSERT(bio->bi_iter.bi_size);
-       ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
-       if (ret)
-               return ret;
-       ret = btrfs_map_bio(fs_info, bio, mirror_num);
-       return ret;
-}
-
 /*
  * Allocate a compressed_bio, which will be used to read/write on-disk
  * (aka, compressed) * data.
@@ -528,7 +522,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
        cb->compressed_pages = compressed_pages;
        cb->compressed_len = compressed_len;
        cb->writeback = writeback;
-       cb->orig_bio = NULL;
+       INIT_WORK(&cb->write_end_work, btrfs_finish_compressed_write_work);
        cb->nr_pages = nr_pages;
 
        if (blkcg_css)
@@ -598,7 +592,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
                                        goto finish_cb;
                        }
 
-                       ret = submit_compressed_bio(fs_info, bio, 0);
+                       ASSERT(bio->bi_iter.bi_size);
+                       ret = btrfs_map_bio(fs_info, bio, 0);
                        if (ret)
                                goto finish_cb;
                        bio = NULL;
@@ -935,7 +930,12 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                                                  fs_info->sectorsize);
                        sums += fs_info->csum_size * nr_sectors;
 
-                       ret = submit_compressed_bio(fs_info, comp_bio, mirror_num);
+                       ASSERT(comp_bio->bi_iter.bi_size);
+                       ret = btrfs_bio_wq_end_io(fs_info, comp_bio,
+                                                 BTRFS_WQ_ENDIO_DATA);
+                       if (ret)
+                               goto finish_cb;
+                       ret = btrfs_map_bio(fs_info, comp_bio, mirror_num);
                        if (ret)
                                goto finish_cb;
                        comp_bio = NULL;

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 2707404..5fca760 100644 (file)
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -61,8 +61,11 @@ struct compressed_bio {
        blk_status_t status;
        int mirror_num;
 
-       /* for reads, this is the bio we are copying the data into */
-       struct bio *orig_bio;
+       union {
+               /* For reads, this is the bio we are copying the data into */
+               struct bio *orig_bio;
+               struct work_struct write_end_work;
+       };
 
        /*
         * the start of a variable length array of checksums only

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1d5b38f..e689dba 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -854,7 +854,7 @@ struct btrfs_fs_info {
        struct btrfs_workqueue *endio_meta_workers;
        struct workqueue_struct *endio_raid56_workers;
        struct workqueue_struct *rmw_workers;
-       struct btrfs_workqueue *endio_meta_write_workers;
+       struct workqueue_struct *compressed_write_workers;
        struct btrfs_workqueue *endio_write_workers;
        struct btrfs_workqueue *endio_freespace_worker;
        struct btrfs_workqueue *caching_workers;

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1c9c6c2..ea32627 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -749,19 +749,10 @@ static void end_workqueue_bio(struct bio *bio)
        fs_info = end_io_wq->info;
        end_io_wq->status = bio->bi_status;
 
-       if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
-               if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
-                       wq = fs_info->endio_meta_write_workers;
-               else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
-                       wq = fs_info->endio_freespace_worker;
-               else
-                       wq = fs_info->endio_write_workers;
-       } else {
-               if (end_io_wq->metadata)
-                       wq = fs_info->endio_meta_workers;
-               else
-                       wq = fs_info->endio_workers;
-       }
+       if (end_io_wq->metadata)
+               wq = fs_info->endio_meta_workers;
+       else
+               wq = fs_info->endio_workers;
 
        btrfs_init_work(&end_io_wq->work, end_workqueue_fn, NULL, NULL);
        btrfs_queue_work(wq, &end_io_wq->work);
@@ -772,6 +763,9 @@ blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 {
        struct btrfs_end_io_wq *end_io_wq;
 
+       if (WARN_ON_ONCE(btrfs_op(bio) != BTRFS_MAP_WRITE))
+               return BLK_STS_IOERR;
+
        end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
        if (!end_io_wq)
                return BLK_STS_RESOURCE;
@@ -2281,6 +2275,8 @@ static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
                destroy_workqueue(fs_info->endio_raid56_workers);
        if (fs_info->rmw_workers)
                destroy_workqueue(fs_info->rmw_workers);
+       if (fs_info->compressed_write_workers)
+               destroy_workqueue(fs_info->compressed_write_workers);
        btrfs_destroy_workqueue(fs_info->endio_write_workers);
        btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
        btrfs_destroy_workqueue(fs_info->delayed_workers);
@@ -2295,7 +2291,6 @@ static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
         * queues can do metadata I/O operations.
         */
        btrfs_destroy_workqueue(fs_info->endio_meta_workers);
-       btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
 }
 
 static void free_root_extent_buffers(struct btrfs_root *root)
@@ -2483,15 +2478,14 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
        fs_info->endio_meta_workers =
                btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
                                      max_active, 4);
-       fs_info->endio_meta_write_workers =
-               btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
-                                     max_active, 2);
        fs_info->endio_raid56_workers =
                alloc_workqueue("btrfs-endio-raid56", flags, max_active);
        fs_info->rmw_workers = alloc_workqueue("btrfs-rmw", flags, max_active);
        fs_info->endio_write_workers =
                btrfs_alloc_workqueue(fs_info, "endio-write", flags,
                                      max_active, 2);
+       fs_info->compressed_write_workers =
+               alloc_workqueue("btrfs-compressed-write", flags, max_active);
        fs_info->endio_freespace_worker =
                btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
                                      max_active, 0);
@@ -2506,7 +2500,7 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
        if (!(fs_info->workers && fs_info->hipri_workers &&
              fs_info->delalloc_workers && fs_info->flush_workers &&
              fs_info->endio_workers && fs_info->endio_meta_workers &&
-             fs_info->endio_meta_write_workers &&
+             fs_info->compressed_write_workers &&
              fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
              fs_info->endio_freespace_worker && fs_info->rmw_workers &&
              fs_info->caching_workers && fs_info->fixup_workers &&

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8539ee2..e3800f0 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1934,8 +1934,6 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
        btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
        btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
        btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
-       btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
-                               new_pool_size);
        btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
        btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
        btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);