On Wed, Oct 09, 2019 at 11:52:41AM +0530, Ritesh Harjani wrote:
> On 10/3/19 5:03 PM, Matthew Bobrowski wrote:
> Minor comment, but otherwise.
> Patch looks good to me. You may add:
>
> Reviewed-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
*nod* - Thank you!
> > static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> > unsigned flags, struct iomap *iomap)
> > {
> > @@ -3500,62 +3556,16 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> > }
> > }
> > } else if (flags & IOMAP_WRITE) {
> > - int dio_credits;
> > - handle_t *handle;
> > - int retries = 0;
> > -
> > - /* Trim mapping request to maximum we can map at once for DIO */
> > - if (map.m_len > DIO_MAX_BLOCKS)
> > - map.m_len = DIO_MAX_BLOCKS;
> > - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
> > -retry:
> > - /*
> > - * Either we allocate blocks and then we don't get unwritten
> > - * extent so we have reserved enough credits, or the blocks
> > - * are already allocated and unwritten and in that case
> > - * extent conversion fits in the credits as well.
> > - */
> > - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
> > - dio_credits);
> > - if (IS_ERR(handle))
> > - return PTR_ERR(handle);
> > -
> > - ret = ext4_map_blocks(handle, inode, &map,
> > - EXT4_GET_BLOCKS_CREATE_ZERO);
> > - if (ret < 0) {
> > - ext4_journal_stop(handle);
> > - if (ret == -ENOSPC &&
> > - ext4_should_retry_alloc(inode->i_sb, &retries))
> > - goto retry;
> > - return ret;
> > - }
> > -
> > - /*
> > - * If we added blocks beyond i_size, we need to make sure they
> > - * will get truncated if we crash before updating i_size in
> > - * ext4_iomap_end(). For faults we don't need to do that (and
> > - * even cannot because for orphan list operations inode_lock is
> > - * required) - if we happen to instantiate block beyond i_size,
> > - * it is because we race with truncate which has already added
> > - * the inode to the orphan list.
> > - */
> > - if (!(flags & IOMAP_FAULT) && first_block + map.m_len >
> > - (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) {
> > - int err;
> > -
> > - err = ext4_orphan_add(handle, inode);
> > - if (err < 0) {
> > - ext4_journal_stop(handle);
> > - return err;
> > - }
> > - }
> > - ext4_journal_stop(handle);
> > + ret = ext4_iomap_alloc(inode, flags, first_block, &map);
>
> We don't need "first_block" argument here. Since
> map->m_lblk saves first_block directly above in the same function.
You're right. I will change that.
> No strong objection against ext4_iomap_alloc, but
> maybe ext4_iomap_map_write sounds better?
> Either way is fine though.
I like 'ext4_iomap_alloc', because it's performing allocation in
preparation for a write being performed on behalf of iomap. :)
--<M>--
