On Wed, Jan 27, 2021 at 02:57:27PM +0100, Michal Rostecki wrote:
> From: Michal Rostecki <mroste...@suse.com>
>
> Before this change, the btrfs_get_io_geometry() function was calling
> btrfs_get_chunk_map() to get the extent mapping, necessary for
> calculating the I/O geometry. It was using that extent mapping only
> internally and freeing the pointer after its execution.
>
> That resulted in calling btrfs_get_chunk_map() de facto twice by the
> __btrfs_map_block() function. It was calling btrfs_get_io_geometry()
> first and then calling btrfs_get_chunk_map() directly to get the extent
> mapping, used by the rest of the function.
>
> This change fixes that by passing the extent mapping to the
> btrfs_get_io_geometry() function as an argument.
>
> v2:
> When btrfs_get_chunk_map() returns an error in btrfs_submit_direct():
> - Use errno_to_blk_status(PTR_ERR(em)) as the status
> - Set em to NULL
The version-to-version changelog belongs under the -- line. If there's
something relevant in v2 it should be put into the proper changelog but
normal fixups like 'set em to NULL' do not have the long-term value that
we want to record in the changelog.
> Signed-off-by: Michal Rostecki <mroste...@suse.com>
> ---
> fs/btrfs/inode.c | 38 +++++++++++++++++++++++++++++---------
> fs/btrfs/volumes.c | 39 ++++++++++++++++-----------------------
> fs/btrfs/volumes.h | 5 +++--
> 3 files changed, 48 insertions(+), 34 deletions(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 0dbe1aaa0b71..e2ee3a9c1140 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2183,9 +2183,10 @@ int btrfs_bio_fits_in_stripe(struct page *page, size_t
> size, struct bio *bio,
> struct inode *inode = page->mapping->host;
> struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> u64 logical = bio->bi_iter.bi_sector << 9;
> + struct extent_map *em;
> u64 length = 0;
> u64 map_length;
> - int ret;
> + int ret = 0;
> struct btrfs_io_geometry geom;
>
> if (bio_flags & EXTENT_BIO_COMPRESSED)
> @@ -2193,14 +2194,21 @@ int btrfs_bio_fits_in_stripe(struct page *page,
> size_t size, struct bio *bio,
>
> length = bio->bi_iter.bi_size;
> map_length = length;
> - ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length,
> - &geom);
> + em = btrfs_get_chunk_map(fs_info, logical, map_length);
> + if (IS_ERR(em))
> + return PTR_ERR(em);
> + ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(bio), logical,
> + map_length, &geom);
> if (ret < 0)
> - return ret;
> + goto out;
>
> - if (geom.len < length + size)
> - return 1;
> - return 0;
> + if (geom.len < length + size) {
> + ret = 1;
> + goto out;
> + }
> +out:
> + free_extent_map(em);
> + return ret;
> }
>
> /*
> @@ -7941,10 +7949,12 @@ static blk_qc_t btrfs_submit_direct(struct inode
> *inode, struct iomap *iomap,
> u64 submit_len;
> int clone_offset = 0;
> int clone_len;
> + int logical;
This needs to be u64
> int ret;
> blk_status_t status;
> struct btrfs_io_geometry geom;
> struct btrfs_dio_data *dio_data = iomap->private;
> + struct extent_map *em;
>
> dip = btrfs_create_dio_private(dio_bio, inode, file_offset);
> if (!dip) {
> @@ -7970,11 +7980,18 @@ static blk_qc_t btrfs_submit_direct(struct inode
> *inode, struct iomap *iomap,
> }
>
> start_sector = dio_bio->bi_iter.bi_sector;
> + logical = start_sector << 9;
Otherwise this overflows on logical address larger than 2^23 which is 8G.
