On 16:27 14/10, Darrick J. Wong wrote: > On Tue, Oct 08, 2019 at 09:15:15AM +0200, Christoph Hellwig wrote: > > From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> > > > > The srcmap is used to identify where the read is to be performed from. > > It is passed to ->iomap_begin, which can fill it in if we need to read > > data for partially written blocks from a different location than the > > write target. The srcmap is only supported for buffered writes so far. > > > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> > > Goldwyn, > > Since we've reworked your original patch quite extensively, could you > please have a look at (and if you approve, add an Acked-by) this new(er) > version so we can get this series moving for 5.5? > > Sorry, was on vacation until yesterday. Yes, I have used this version in my series and I can confirm it works correctly with btrfs. Thanks! > > [hch: merged two patches, removed the IOMAP_F_COW flag, use iomap as > > srcmap if not set, adjust length down to srcmap end as well] Acked-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > --- > > fs/dax.c | 9 ++++-- > > fs/ext2/inode.c | 2 +- > > fs/ext4/inode.c | 2 +- > > fs/gfs2/bmap.c | 3 +- > > fs/iomap/apply.c | 25 ++++++++++++---- > > fs/iomap/buffered-io.c | 65 +++++++++++++++++++++++------------------- > > fs/iomap/direct-io.c | 2 +- > > fs/iomap/fiemap.c | 4 +-- > > fs/iomap/seek.c | 4 +-- > > fs/iomap/swapfile.c | 3 +- > > fs/xfs/xfs_iomap.c | 9 ++++-- > > include/linux/iomap.h | 5 ++-- > > 12 files changed, 80 insertions(+), 53 deletions(-) > > > > diff --git a/fs/dax.c b/fs/dax.c > > index 6bf81f931de3..920105457c2c 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -1090,7 +1090,7 @@ EXPORT_SYMBOL_GPL(__dax_zero_page_range); > > > > static loff_t > > dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > - struct iomap *iomap) > > + struct iomap *iomap, struct iomap *srcmap) > > { > > struct block_device *bdev = iomap->bdev; > > struct dax_device *dax_dev = iomap->dax_dev; > > @@ -1248,6 +1248,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, > > unsigned long vaddr = vmf->address; > > loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; > > struct iomap iomap = { 0 }; > > + struct iomap srcmap = { .type = IOMAP_HOLE }; > > unsigned flags = IOMAP_FAULT; > > int error, major = 0; > > bool write = vmf->flags & FAULT_FLAG_WRITE; > > @@ -1292,7 +1293,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, > > * the file system block size to be equal the page size, which means > > * that we never have to deal with more than a single extent here. > > */ > > - error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap); > > + error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap, &srcmap); > > if (iomap_errp) > > *iomap_errp = error; > > if (error) { > > @@ -1472,6 +1473,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, > > struct inode *inode = mapping->host; > > vm_fault_t result = VM_FAULT_FALLBACK; > > struct iomap iomap = { 0 }; > > + struct iomap srcmap = { .type = IOMAP_HOLE }; > > pgoff_t max_pgoff; > > void *entry; > > loff_t pos; > > @@ -1546,7 +1548,8 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, > > * to look up our filesystem block. > > */ > > pos = (loff_t)xas.xa_index << PAGE_SHIFT; > > - error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap); > > + error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap, > > + &srcmap); > > if (error) > > goto unlock_entry; > > > > diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c > > index 7004ce581a32..467c13ff6b40 100644 > > --- a/fs/ext2/inode.c > > +++ b/fs/ext2/inode.c > > @@ -801,7 +801,7 @@ int ext2_get_block(struct inode *inode, sector_t iblock, > > > > #ifdef CONFIG_FS_DAX > > static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > - unsigned flags, struct iomap *iomap) > > + unsigned flags, struct iomap *iomap, struct iomap *srcmap) > > { > > unsigned int blkbits = inode->i_blkbits; > > unsigned long first_block = offset >> blkbits; > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > > index 516faa280ced..abaaf7d96ca4 100644 > > --- a/fs/ext4/inode.c > > +++ b/fs/ext4/inode.c > > @@ -3407,7 +3407,7 @@ static bool ext4_inode_datasync_dirty(struct inode *inode) > > } > > > > static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > - unsigned flags, struct iomap *iomap) > > + unsigned flags, struct iomap *iomap, struct iomap *srcmap) > > { > > struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); > > unsigned int blkbits = inode->i_blkbits; > > diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c > > index f63df54a08c6..516103248272 100644 > > --- a/fs/gfs2/bmap.c > > +++ b/fs/gfs2/bmap.c > > @@ -1149,7 +1149,8 @@ static inline bool gfs2_iomap_need_write_lock(unsigned flags) > > } > > > > static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length, > > - unsigned flags, struct iomap *iomap) > > + unsigned flags, struct iomap *iomap, > > + struct iomap *srcmap) > > { > > struct gfs2_inode *ip = GFS2_I(inode); > > struct metapath mp = { .mp_aheight = 1, }; > > diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c > > index 54c02aecf3cd..484dd8eda861 100644 > > --- a/fs/iomap/apply.c > > +++ b/fs/iomap/apply.c > > @@ -23,8 +23,10 @@ loff_t > > iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, > > const struct iomap_ops *ops, void *data, iomap_actor_t actor) > > { > > - struct iomap iomap = { 0 }; > > + struct iomap iomap = { .type = IOMAP_HOLE }; > > + struct iomap srcmap = { .type = IOMAP_HOLE }; > > loff_t written = 0, ret; > > + u64 end; > > > > /* > > * Need to map a range from start position for length bytes. This can > > @@ -38,7 +40,7 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, > > * expose transient stale data. If the reserve fails, we can safely > > * back out at this point as there is nothing to undo. > > */ > > - ret = ops->iomap_begin(inode, pos, length, flags, &iomap); > > + ret = ops->iomap_begin(inode, pos, length, flags, &iomap, &srcmap); > > if (ret) > > return ret; > > if (WARN_ON(iomap.offset > pos)) > > @@ -50,15 +52,26 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, > > * Cut down the length to the one actually provided by the filesystem, > > * as it might not be able to give us the whole size that we requested. > > */ > > - if (iomap.offset + iomap.length < pos + length) > > - length = iomap.offset + iomap.length - pos; > > + end = iomap.offset + iomap.length; > > + if (srcmap.type != IOMAP_HOLE) > > + end = min(end, srcmap.offset + srcmap.length); > > + if (pos + length > end) > > + length = end - pos; > > > > /* > > - * Now that we have guaranteed that the space allocation will succeed. > > + * Now that we have guaranteed that the space allocation will succeed, > > * we can do the copy-in page by page without having to worry about > > * failures exposing transient data. > > + * > > + * To support COW operations, we read in data for partially blocks from > > + * the srcmap if the file system filled it in. In that case we the > > + * length needs to be limited to the earlier of the ends of the iomaps. > > + * If the file system did not provide a srcmap we pass in the normal > > + * iomap into the actors so that they don't need to have special > > + * handling for the two cases. > > */ > > - written = actor(inode, pos, length, data, &iomap); > > + written = actor(inode, pos, length, data, &iomap, > > + srcmap.type != IOMAP_HOLE ? &srcmap : &iomap); > > > > /* > > * Now the data has been copied, commit the range we've copied. This > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > > index ac1bbed71a9b..eb2c6d73a837 100644 > > --- a/fs/iomap/buffered-io.c > > +++ b/fs/iomap/buffered-io.c > > @@ -234,7 +234,7 @@ static inline bool iomap_block_needs_zeroing(struct inode *inode, > > > > static loff_t > > iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > - struct iomap *iomap) > > + struct iomap *iomap, struct iomap *srcmap) > > { > > struct iomap_readpage_ctx *ctx = data; > > struct page *page = ctx->cur_page; > > @@ -382,7 +382,7 @@ iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos, > > > > static loff_t > > iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > struct iomap_readpage_ctx *ctx = data; > > loff_t done, ret; > > @@ -402,7 +402,7 @@ iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length, > > ctx->cur_page_in_bio = false; > > } > > ret = iomap_readpage_actor(inode, pos + done, length - done, > > - ctx, iomap); > > + ctx, iomap, srcmap); > > } > > > > return done; > > @@ -582,7 +582,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, > > > > static int > > __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > > - struct page *page, struct iomap *iomap) > > + struct page *page, struct iomap *srcmap) > > { > > struct iomap_page *iop = iomap_page_create(inode, page); > > loff_t block_size = i_blocksize(inode); > > @@ -605,7 +605,7 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > > (to <= poff || to >= poff + plen)) > > continue; > > > > - if (iomap_block_needs_zeroing(inode, iomap, block_start)) { > > + if (iomap_block_needs_zeroing(inode, srcmap, block_start)) { > > if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) > > return -EIO; > > zero_user_segments(page, poff, from, to, poff + plen); > > @@ -614,7 +614,7 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > > } > > > > status = iomap_read_page_sync(block_start, page, poff, plen, > > - iomap); > > + srcmap); > > if (status) > > return status; > > } while ((block_start += plen) < block_end); > > @@ -624,13 +624,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > > > > static int > > iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, > > - struct page **pagep, struct iomap *iomap) > > + struct page **pagep, struct iomap *iomap, struct iomap *srcmap) > > { > > const struct iomap_page_ops *page_ops = iomap->page_ops; > > struct page *page; > > int status = 0; > > > > BUG_ON(pos + len > iomap->offset + iomap->length); > > + if (srcmap != iomap) > > + BUG_ON(pos + len > srcmap->offset + srcmap->length); > > > > if (fatal_signal_pending(current)) > > return -EINTR; > > @@ -648,13 +650,13 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, > > goto out_no_page; > > } > > > > - if (iomap->type == IOMAP_INLINE) > > - iomap_read_inline_data(inode, page, iomap); > > + if (srcmap->type == IOMAP_INLINE) > > + iomap_read_inline_data(inode, page, srcmap); > > else if (iomap->flags & IOMAP_F_BUFFER_HEAD) > > - status = __block_write_begin_int(page, pos, len, NULL, iomap); > > + status = __block_write_begin_int(page, pos, len, NULL, srcmap); > > else > > status = __iomap_write_begin(inode, pos, len, flags, page, > > - iomap); > > + srcmap); > > > > if (unlikely(status)) > > goto out_unlock; > > @@ -740,16 +742,16 @@ iomap_write_end_inline(struct inode *inode, struct page *page, > > } > > > > static int > > -iomap_write_end(struct inode *inode, loff_t pos, unsigned len, > > - unsigned copied, struct page *page, struct iomap *iomap) > > +iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, > > + struct page *page, struct iomap *iomap, struct iomap *srcmap) > > { > > const struct iomap_page_ops *page_ops = iomap->page_ops; > > loff_t old_size = inode->i_size; > > int ret; > > > > - if (iomap->type == IOMAP_INLINE) { > > + if (srcmap->type == IOMAP_INLINE) { > > ret = iomap_write_end_inline(inode, page, iomap, pos, copied); > > - } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { > > + } else if (srcmap->flags & IOMAP_F_BUFFER_HEAD) { > > ret = block_write_end(NULL, inode->i_mapping, pos, len, copied, > > page, NULL); > > } else { > > @@ -780,7 +782,7 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, > > > > static loff_t > > iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > - struct iomap *iomap) > > + struct iomap *iomap, struct iomap *srcmap) > > { > > struct iov_iter *i = data; > > long status = 0; > > @@ -814,7 +816,8 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > break; > > } > > > > - status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap); > > + status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, > > + srcmap); > > if (unlikely(status)) > > break; > > > > @@ -825,8 +828,8 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > > > flush_dcache_page(page); > > > > - status = iomap_write_end(inode, pos, bytes, copied, page, > > - iomap); > > + status = iomap_write_end(inode, pos, bytes, copied, page, iomap, > > + srcmap); > > if (unlikely(status < 0)) > > break; > > copied = status; > > @@ -879,7 +882,7 @@ EXPORT_SYMBOL_GPL(iomap_file_buffered_write); > > > > static loff_t > > iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > - struct iomap *iomap) > > + struct iomap *iomap, struct iomap *srcmap) > > { > > long status = 0; > > ssize_t written = 0; > > @@ -888,7 +891,7 @@ iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > if (!(iomap->flags & IOMAP_F_SHARED)) > > return length; > > /* don't bother with holes or unwritten extents */ > > - if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN) > > + if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) > > return length; > > > > do { > > @@ -897,11 +900,12 @@ iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > struct page *page; > > > > status = iomap_write_begin(inode, pos, bytes, > > - IOMAP_WRITE_F_UNSHARE, &page, iomap); > > + IOMAP_WRITE_F_UNSHARE, &page, iomap, srcmap); > > if (unlikely(status)) > > return status; > > > > - status = iomap_write_end(inode, pos, bytes, bytes, page, iomap); > > + status = iomap_write_end(inode, pos, bytes, bytes, page, iomap, > > + srcmap); > > if (unlikely(status <= 0)) { > > if (WARN_ON_ONCE(status == 0)) > > return -EIO; > > @@ -940,19 +944,19 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, > > EXPORT_SYMBOL_GPL(iomap_file_unshare); > > > > static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, > > - unsigned bytes, struct iomap *iomap) > > + unsigned bytes, struct iomap *iomap, struct iomap *srcmap) > > { > > struct page *page; > > int status; > > > > - status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap); > > + status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap); > > if (status) > > return status; > > > > zero_user(page, offset, bytes); > > mark_page_accessed(page); > > > > - return iomap_write_end(inode, pos, bytes, bytes, page, iomap); > > + return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); > > } > > > > static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes, > > @@ -964,14 +968,14 @@ static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes, > > > > static loff_t > > iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > bool *did_zero = data; > > loff_t written = 0; > > int status; > > > > /* already zeroed? we're done. */ > > - if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN) > > + if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) > > return count; > > > > do { > > @@ -983,7 +987,8 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count, > > if (IS_DAX(inode)) > > status = iomap_dax_zero(pos, offset, bytes, iomap); > > else > > - status = iomap_zero(inode, pos, offset, bytes, iomap); > > + status = iomap_zero(inode, pos, offset, bytes, iomap, > > + srcmap); > > if (status < 0) > > return status; > > > > @@ -1033,7 +1038,7 @@ EXPORT_SYMBOL_GPL(iomap_truncate_page); > > > > static loff_t > > iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > struct page *page = data; > > int ret; > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > > index 1fc28c2da279..e3ccbf7daaae 100644 > > --- a/fs/iomap/direct-io.c > > +++ b/fs/iomap/direct-io.c > > @@ -358,7 +358,7 @@ iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length, > > > > static loff_t > > iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > struct iomap_dio *dio = data; > > > > diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c > > index f26fdd36e383..690ef2d7c6c8 100644 > > --- a/fs/iomap/fiemap.c > > +++ b/fs/iomap/fiemap.c > > @@ -44,7 +44,7 @@ static int iomap_to_fiemap(struct fiemap_extent_info *fi, > > > > static loff_t > > iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > > - struct iomap *iomap) > > + struct iomap *iomap, struct iomap *srcmap) > > { > > struct fiemap_ctx *ctx = data; > > loff_t ret = length; > > @@ -111,7 +111,7 @@ EXPORT_SYMBOL_GPL(iomap_fiemap); > > > > static loff_t > > iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > sector_t *bno = data, addr; > > > > diff --git a/fs/iomap/seek.c b/fs/iomap/seek.c > > index c04bad4b2b43..89f61d93c0bc 100644 > > --- a/fs/iomap/seek.c > > +++ b/fs/iomap/seek.c > > @@ -119,7 +119,7 @@ page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length, > > > > static loff_t > > iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > switch (iomap->type) { > > case IOMAP_UNWRITTEN: > > @@ -165,7 +165,7 @@ EXPORT_SYMBOL_GPL(iomap_seek_hole); > > > > static loff_t > > iomap_seek_data_actor(struct inode *inode, loff_t offset, loff_t length, > > - void *data, struct iomap *iomap) > > + void *data, struct iomap *iomap, struct iomap *srcmap) > > { > > switch (iomap->type) { > > case IOMAP_HOLE: > > diff --git a/fs/iomap/swapfile.c b/fs/iomap/swapfile.c > > index 152a230f668d..a648dbf6991e 100644 > > --- a/fs/iomap/swapfile.c > > +++ b/fs/iomap/swapfile.c > > @@ -76,7 +76,8 @@ static int iomap_swapfile_add_extent(struct iomap_swapfile_info *isi) > > * distinction between written and unwritten extents. > > */ > > static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos, > > - loff_t count, void *data, struct iomap *iomap) > > + loff_t count, void *data, struct iomap *iomap, > > + struct iomap *srcmap) > > { > > struct iomap_swapfile_info *isi = data; > > int error; > > diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c > > index c0a492353826..016adcd7dd66 100644 > > --- a/fs/xfs/xfs_iomap.c > > +++ b/fs/xfs/xfs_iomap.c > > @@ -928,7 +928,8 @@ xfs_file_iomap_begin( > > loff_t offset, > > loff_t length, > > unsigned flags, > > - struct iomap *iomap) > > + struct iomap *iomap, > > + struct iomap *srcmap) > > { > > struct xfs_inode *ip = XFS_I(inode); > > struct xfs_mount *mp = ip->i_mount; > > @@ -1154,7 +1155,8 @@ xfs_seek_iomap_begin( > > loff_t offset, > > loff_t length, > > unsigned flags, > > - struct iomap *iomap) > > + struct iomap *iomap, > > + struct iomap *srcmap) > > { > > struct xfs_inode *ip = XFS_I(inode); > > struct xfs_mount *mp = ip->i_mount; > > @@ -1240,7 +1242,8 @@ xfs_xattr_iomap_begin( > > loff_t offset, > > loff_t length, > > unsigned flags, > > - struct iomap *iomap) > > + struct iomap *iomap, > > + struct iomap *srcmap) > > { > > struct xfs_inode *ip = XFS_I(inode); > > struct xfs_mount *mp = ip->i_mount; > > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > > index 24c784e44274..37af5f9dc722 100644 > > --- a/include/linux/iomap.h > > +++ b/include/linux/iomap.h > > @@ -127,7 +127,8 @@ struct iomap_ops { > > * The actual length is returned in iomap->length. > > */ > > int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, > > - unsigned flags, struct iomap *iomap); > > + unsigned flags, struct iomap *iomap, > > + struct iomap *srcmap); > > > > /* > > * Commit and/or unreserve space previous allocated using iomap_begin. > > @@ -143,7 +144,7 @@ struct iomap_ops { > > * Main iomap iterator function. > > */ > > typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len, > > - void *data, struct iomap *iomap); > > + void *data, struct iomap *iomap, struct iomap *srcmap); > > > > loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, > > unsigned flags, const struct iomap_ops *ops, void *data, > > -- > > 2.20.1 > > > -- Goldwyn