From: Andreas Gruenbacher <agruenba@xxxxxxxxxx> In iomap_to_bh, not only mark buffer heads in IOMAP_UNWRITTEN maps as new, but also buffer heads in IOMAP_MAPPED maps with the IOMAP_F_NEW flag set. This will be used by filesystems like gfs2, which allocate blocks in iomap->begin. Minor corrections to the comment for IOMAP_UNWRITTEN maps. Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- fs/buffer.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index aba2a948b235..c8c2b7d8b8d6 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1900,15 +1900,16 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh, break; case IOMAP_UNWRITTEN: /* - * For unwritten regions, we always need to ensure that - * sub-block writes cause the regions in the block we are not - * writing to are zeroed. Set the buffer as new to ensure this. + * For unwritten regions, we always need to ensure that regions + * in the block we are not writing to are zeroed. Mark the + * buffer as new to ensure this. */ set_buffer_new(bh); set_buffer_unwritten(bh); /* FALLTHRU */ case IOMAP_MAPPED: - if (offset >= i_size_read(inode)) + if ((iomap->flags & IOMAP_F_NEW) || + offset >= i_size_read(inode)) set_buffer_new(bh); bh->b_blocknr = (iomap->addr + offset - iomap->offset) >> inode->i_blkbits; -- 2.14.2