On Thu 03-10-19 21:33:09, Matthew Bobrowski wrote:
> Separate the iomap field population chunk into a separate simple
> helper routine. This helps reducing the overall clutter within the
> ext4_iomap_begin() callback, especially as we move across more code to
> make use of iomap infrastructure.
>
> Signed-off-by: Matthew Bobrowski <mbobrowski@xxxxxxxxxxxxxx>
> ---
> fs/ext4/inode.c | 65 ++++++++++++++++++++++++++++---------------------
> 1 file changed, 37 insertions(+), 28 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 516faa280ced..1ccdc14c4d69 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3406,10 +3406,43 @@ static bool ext4_inode_datasync_dirty(struct inode *inode)
> return inode->i_state & I_DIRTY_DATASYNC;
> }
>
> +static int ext4_set_iomap(struct inode *inode, struct iomap *iomap, u16 type,
> + unsigned long first_block, struct ext4_map_blocks *map)
> +{
> + u8 blkbits = inode->i_blkbits;
> +
> + iomap->flags = 0;
> + if (ext4_inode_datasync_dirty(inode))
> + iomap->flags |= IOMAP_F_DIRTY;
> + iomap->bdev = inode->i_sb->s_bdev;
> + iomap->dax_dev = EXT4_SB(inode->i_sb)->s_daxdev;
> + iomap->offset = (u64) first_block << blkbits;
> + iomap->length = (u64) map->m_len << blkbits;
> +
> + if (type) {
> + iomap->type = type;
> + iomap->addr = IOMAP_NULL_ADDR;
> + } else {
> + if (map->m_flags & EXT4_MAP_MAPPED) {
> + iomap->type = IOMAP_MAPPED;
> + } else if (map->m_flags & EXT4_MAP_UNWRITTEN) {
> + iomap->type = IOMAP_UNWRITTEN;
> + } else {
> + WARN_ON_ONCE(1);
> + return -EIO;
> + }
> + iomap->addr = (u64) map->m_pblk << blkbits;
> + }
Looking at this function now, the 'type' argument looks a bit weird. Can we
perhaps just remove the 'type' argument and change the above to:
if (map->m_flags & (EXT4_MAP_MAPPED | EXT4_MAP_UNWRITTEN)) {
if (map->m_flags & EXT4_MAP_MAPPED)
iomap->type = IOMAP_MAPPED;
else if (map->m_flags & EXT4_MAP_UNWRITTEN)
iomap->type = IOMAP_UNWRITTEN;
iomap->addr = (u64) map->m_pblk << blkbits;
} else {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
}
And then in ext4_iomap_begin() we overwrite the type to:
if (delalloc && iomap->type == IOMAP_HOLE)
iomap->type = IOMAP_DELALLOC;
That would IMO make ext4_set_iomap() arguments harder to get wrong.
Honza
> +
> + if (map->m_flags & EXT4_MAP_NEW)
> + iomap->flags |= IOMAP_F_NEW;
> + return 0;
> +}
> +
> static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> unsigned flags, struct iomap *iomap)
> {
> - struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> + u16 type = 0;
> unsigned int blkbits = inode->i_blkbits;
> unsigned long first_block, last_block;
> struct ext4_map_blocks map;
> @@ -3523,33 +3556,9 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> return ret;
> }
>
> - iomap->flags = 0;
> - if (ext4_inode_datasync_dirty(inode))
> - iomap->flags |= IOMAP_F_DIRTY;
> - iomap->bdev = inode->i_sb->s_bdev;
> - iomap->dax_dev = sbi->s_daxdev;
> - iomap->offset = (u64)first_block << blkbits;
> - iomap->length = (u64)map.m_len << blkbits;
> -
> - if (ret == 0) {
> - iomap->type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE;
> - iomap->addr = IOMAP_NULL_ADDR;
> - } else {
> - if (map.m_flags & EXT4_MAP_MAPPED) {
> - iomap->type = IOMAP_MAPPED;
> - } else if (map.m_flags & EXT4_MAP_UNWRITTEN) {
> - iomap->type = IOMAP_UNWRITTEN;
> - } else {
> - WARN_ON_ONCE(1);
> - return -EIO;
> - }
> - iomap->addr = (u64)map.m_pblk << blkbits;
> - }
> -
> - if (map.m_flags & EXT4_MAP_NEW)
> - iomap->flags |= IOMAP_F_NEW;
> -
> - return 0;
> + if (!ret)
> + type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE;
> + return ext4_set_iomap(inode, iomap, type, first_block, &map);
> }
>
> static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
> --
> 2.20.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
