btrfs: allocate the btrfs_dio_private as part of the iomap dio bio

Create a new bio_set that contains all the per-bio private data needed
by btrfs for direct I/O and tell the iomap code to use that instead
of separately allocation the btrfs_dio_private structure.

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

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 84b0a05..1b76fc4 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -85,13 +85,15 @@ struct btrfs_dio_private {
         */
        refcount_t refs;
 
-       /* dio_bio came from fs/direct-io.c */
-       struct bio *dio_bio;
-
        /* Array of checksums */
-       u8 csums[];
+       u8 *csums;
+
+       /* This must be last */
+       struct bio bio;
 };
 
+static struct bio_set btrfs_dio_bioset;
+
 struct btrfs_rename_ctx {
        /* Output field. Stores the index number of the old directory entry. */
        u64 index;
@@ -7828,19 +7830,19 @@ static void btrfs_dio_private_put(struct btrfs_dio_private *dip)
        if (!refcount_dec_and_test(&dip->refs))
                return;
 
-       if (btrfs_op(dip->dio_bio) == BTRFS_MAP_WRITE) {
+       if (btrfs_op(&dip->bio) == BTRFS_MAP_WRITE) {
                __endio_write_update_ordered(BTRFS_I(dip->inode),
                                             dip->file_offset,
                                             dip->bytes,
-                                            !dip->dio_bio->bi_status);
+                                            !dip->bio.bi_status);
        } else {
                unlock_extent(&BTRFS_I(dip->inode)->io_tree,
                              dip->file_offset,
                              dip->file_offset + dip->bytes - 1);
        }
 
-       bio_endio(dip->dio_bio);
-       kfree(dip);
+       kfree(dip->csums);
+       bio_endio(&dip->bio);
 }
 
 static void submit_dio_repair_bio(struct inode *inode, struct bio *bio,
@@ -7942,7 +7944,7 @@ static void btrfs_end_dio_bio(struct bio *bio)
                err = btrfs_check_read_dio_bio(dip, bbio, !err);
 
        if (err)
-               dip->dio_bio->bi_status = err;
+               dip->bio.bi_status = err;
 
        btrfs_record_physical_zoned(dip->inode, bbio->file_offset, bio);
 
@@ -7997,49 +7999,16 @@ err:
        return ret;
 }
 
-/*
- * If this succeeds, the btrfs_dio_private is responsible for cleaning up locked
- * or ordered extents whether or not we submit any bios.
- */
-static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
-                                                         struct inode *inode,
-                                                         loff_t file_offset)
-{
-       const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
-       const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
-       size_t dip_size;
-       struct btrfs_dio_private *dip;
-
-       dip_size = sizeof(*dip);
-       if (!write && csum) {
-               struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-               size_t nblocks;
-
-               nblocks = dio_bio->bi_iter.bi_size >> fs_info->sectorsize_bits;
-               dip_size += fs_info->csum_size * nblocks;
-       }
-
-       dip = kzalloc(dip_size, GFP_NOFS);
-       if (!dip)
-               return NULL;
-
-       dip->inode = inode;
-       dip->file_offset = file_offset;
-       dip->bytes = dio_bio->bi_iter.bi_size;
-       dip->dio_bio = dio_bio;
-       refcount_set(&dip->refs, 1);
-       return dip;
-}
-
 static void btrfs_submit_direct(const struct iomap_iter *iter,
                struct bio *dio_bio, loff_t file_offset)
 {
+       struct btrfs_dio_private *dip =
+               container_of(dio_bio, struct btrfs_dio_private, bio);
        struct inode *inode = iter->inode;
        const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
        struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
        const bool raid56 = (btrfs_data_alloc_profile(fs_info) &
                             BTRFS_BLOCK_GROUP_RAID56_MASK);
-       struct btrfs_dio_private *dip;
        struct bio *bio;
        u64 start_sector;
        int async_submit = 0;
@@ -8053,24 +8022,25 @@ static void btrfs_submit_direct(const struct iomap_iter *iter,
        struct btrfs_dio_data *dio_data = iter->private;
        struct extent_map *em = NULL;
 
-       dip = btrfs_create_dio_private(dio_bio, inode, file_offset);
-       if (!dip) {
-               if (!write) {
-                       unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
-                               file_offset + dio_bio->bi_iter.bi_size - 1);
-               }
-               dio_bio->bi_status = BLK_STS_RESOURCE;
-               bio_endio(dio_bio);
-               return;
-       }
+       dip->inode = inode;
+       dip->file_offset = file_offset;
+       dip->bytes = dio_bio->bi_iter.bi_size;
+       refcount_set(&dip->refs, 1);
+       dip->csums = NULL;
+
+       if (!write && !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
+               unsigned int nr_sectors =
+                       (dio_bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
 
-       if (!write) {
                /*
                 * Load the csums up front to reduce csum tree searches and
                 * contention when submitting bios.
-                *
-                * If we have csums disabled this will do nothing.
                 */
+               status = BLK_STS_RESOURCE;
+               dip->csums = kcalloc(nr_sectors, fs_info->csum_size, GFP_NOFS);
+               if (!dip)
+                       goto out_err;
+
                status = btrfs_lookup_bio_sums(inode, dio_bio, dip->csums);
                if (status != BLK_STS_OK)
                        goto out_err;
@@ -8160,7 +8130,7 @@ static void btrfs_submit_direct(const struct iomap_iter *iter,
 out_err_em:
        free_extent_map(em);
 out_err:
-       dip->dio_bio->bi_status = status;
+       dio_bio->bi_status = status;
        btrfs_dio_private_put(dip);
 }
 
@@ -8171,6 +8141,7 @@ static const struct iomap_ops btrfs_dio_iomap_ops = {
 
 static const struct iomap_dio_ops btrfs_dio_ops = {
        .submit_io              = btrfs_submit_direct,
+       .bio_set                = &btrfs_dio_bioset,
 };
 
 ssize_t btrfs_dio_rw(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)
@@ -8991,6 +8962,7 @@ void __cold btrfs_destroy_cachep(void)
         * destroy cache.
         */
        rcu_barrier();
+       bioset_exit(&btrfs_dio_bioset);
        kmem_cache_destroy(btrfs_inode_cachep);
        kmem_cache_destroy(btrfs_trans_handle_cachep);
        kmem_cache_destroy(btrfs_path_cachep);
@@ -9031,6 +9003,11 @@ int __init btrfs_init_cachep(void)
        if (!btrfs_free_space_bitmap_cachep)
                goto fail;
 
+       if (bioset_init(&btrfs_dio_bioset, BIO_POOL_SIZE,
+                       offsetof(struct btrfs_dio_private, bio),
+                       BIOSET_NEED_BVECS))
+               goto fail;
+
        return 0;
 fail:
        btrfs_destroy_cachep();