| Message ID | 20190909182722.16783-8-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/19] iomap: better document the IOMAP_F_* flags | expand |
On Mon, 2019-09-09 at 20:27 +0200, Christoph Hellwig wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > 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@suse.com> > [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] > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/dax.c | 9 ++++-- > fs/ext2/inode.c | 2 +- > fs/ext4/inode.c | 2 +- > fs/gfs2/bmap.c | 3 +- > fs/iomap/apply.c | 23 +++++++++++---- > 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, 79 insertions(+), 52 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index a237141d8787..8016be24bbd9 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 = { 0 }; > 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 = { 0 }; > 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 420fe3deed39..e2116e8228d2 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3453,7 +3453,7 @@ 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 79581b9bdebb..0bf8e8fa82bd 100644 > --- a/fs/gfs2/bmap.c > +++ b/fs/gfs2/bmap.c > @@ -1123,7 +1123,8 @@ static int gfs2_iomap_begin_write(struct inode > *inode, loff_t pos, > } > > 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..67efd86675e6 100644 > --- a/fs/iomap/apply.c > +++ b/fs/iomap/apply.c > @@ -24,7 +24,9 @@ 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 srcmap = { 0 }; > 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) > + end = min(end, srcmap.offset + srcmap.length); > + if (pos + length > end) > + length = end - pos; > Yes, that looks more correct. However, can we be smart and not bother setting the minimum of end and srcmap.offset + srcmap.length if it is not required? ie in situations where end coincides with block boundary. Or if srcmap.length falls short, until the last block boundary of iomap? I did think about this scenario. This case is specific to CoW and thought this is best handled by filesystem's iomap_begin(). If this goes in, the filesystems would have to "falsify" srcmap length information to maximize the amount of I/O that goes in one iteration.
On Tue, Sep 10, 2019 at 12:48:14PM +0000, Goldwyn Rodrigues wrote: > > + if (srcmap.type) > > + end = min(end, srcmap.offset + srcmap.length); > > + if (pos + length > end) > > + length = end - pos; > > > > > Yes, that looks more correct. However, can we be smart and not bother > setting the minimum of end and srcmap.offset + srcmap.length if it is > not required? ie in situations where end coincides with block boundary. > Or if srcmap.length falls short, until the last block boundary of > iomap? > > I did think about this scenario. This case is specific to CoW and > thought this is best handled by filesystem's iomap_begin(). If this > goes in, the filesystems would have to "falsify" srcmap length > information to maximize the amount of I/O that goes in one iteration. The problem is really that we can easily run over the srcmap (that's what happened to me with XFS..) One thing you've done in btrfs that I haven't done yet in XFS is to simply not bother with filling out the srcmap if we don't need to (that is if the iteration is fully page aligned in your patch set - the unshare op in this series will complicate things a little). With that optimization the only case where the shortening of the iteration that matters is if the start is unaligned and needs a read-modify-write cycle, but the end is aligned and beyond the end of the srcmap. Is that such an important case? > > -- > Goldwyn---end quoted text---
On Tue, Sep 10, 2019 at 04:39:59PM +0200, hch@lst.de wrote: > On Tue, Sep 10, 2019 at 12:48:14PM +0000, Goldwyn Rodrigues wrote: > > > + if (srcmap.type) > > > + end = min(end, srcmap.offset + srcmap.length); > > > + if (pos + length > end) > > > + length = end - pos; > > > > > > > > > Yes, that looks more correct. However, can we be smart and not bother > > setting the minimum of end and srcmap.offset + srcmap.length if it is > > not required? ie in situations where end coincides with block boundary. > > Or if srcmap.length falls short, until the last block boundary of > > iomap? > > > > I did think about this scenario. This case is specific to CoW and > > thought this is best handled by filesystem's iomap_begin(). If this > > goes in, the filesystems would have to "falsify" srcmap length > > information to maximize the amount of I/O that goes in one iteration. > > The problem is really that we can easily run over the srcmap (that's > what happened to me with XFS..) One thing you've done in btrfs that > I haven't done yet in XFS is to simply not bother with filling out > the srcmap if we don't need to (that is if the iteration is fully > page aligned in your patch set - the unshare op in this series will > complicate things a little). With that optimization the only case > where the shortening of the iteration that matters is if the start > is unaligned and needs a read-modify-write cycle, but the end is > aligned and beyond the end of the srcmap. Is that such an important > case? <shrug> You might as well, since it's still going to be a few weeks until I carve off a iomap work branch for 5.5... :) (He says stumbling in from vacation with half a brain) --D > > > > -- > > Goldwyn---end quoted text---
On Mon, Sep 09, 2019 at 08:27:10PM +0200, Christoph Hellwig wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > 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@suse.com> > [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] > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/dax.c | 9 ++++-- > fs/ext2/inode.c | 2 +- > fs/ext4/inode.c | 2 +- > fs/gfs2/bmap.c | 3 +- > fs/iomap/apply.c | 23 +++++++++++---- > 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, 79 insertions(+), 52 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index a237141d8787..8016be24bbd9 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 = { 0 }; > 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 = { 0 }; > 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 420fe3deed39..e2116e8228d2 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3453,7 +3453,7 @@ 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 79581b9bdebb..0bf8e8fa82bd 100644 > --- a/fs/gfs2/bmap.c > +++ b/fs/gfs2/bmap.c > @@ -1123,7 +1123,8 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, > } > > 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..67efd86675e6 100644 > --- a/fs/iomap/apply.c > +++ b/fs/iomap/apply.c > @@ -24,7 +24,9 @@ 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 srcmap = { 0 }; > 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) Do we need a "#define IOMAP_NULL 0" type to make this more explicit? Or at least a comment in iomap.h above the IOMAP_HOLE definition pointing out that type == 0 is valid for srcmap and not valid for iomap? Other than that the rest looks ok. --D (This reminds me that at some point I ought to work on iomap debugging checks for the mappings returned by ->iomap_begin ...) > + 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 ? &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 a421977a9496..58fb7a894ad4 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -219,7 +219,7 @@ 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; > @@ -367,7 +367,7 @@ 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; > @@ -387,7 +387,7 @@ 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; > @@ -567,7 +567,7 @@ 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); > @@ -590,7 +590,7 @@ __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); > @@ -599,7 +599,7 @@ __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); > @@ -609,13 +609,15 @@ __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; > @@ -633,13 +635,13 @@ 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; > @@ -725,16 +727,16 @@ 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 { > @@ -765,7 +767,7 @@ 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; > @@ -799,7 +801,8 @@ 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; > > @@ -810,8 +813,8 @@ 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; > @@ -864,7 +867,7 @@ 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; > @@ -873,7 +876,7 @@ 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 { > @@ -882,11 +885,12 @@ 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; > @@ -925,19 +929,19 @@ 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, > @@ -949,14 +953,14 @@ 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 { > @@ -968,7 +972,8 @@ 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; > > @@ -1018,7 +1023,7 @@ 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 d340db666c06..f1c3ff27c666 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 3a0f0975a57e..6d795924baa7 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 >
On Mon, Sep 16, 2019 at 11:42:37AM -0700, Darrick J. Wong wrote: > On Mon, Sep 09, 2019 at 08:27:10PM +0200, Christoph Hellwig wrote: <snip> > > diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c > > index 54c02aecf3cd..67efd86675e6 100644 > > --- a/fs/iomap/apply.c > > +++ b/fs/iomap/apply.c > > @@ -24,7 +24,9 @@ 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 srcmap = { 0 }; > > 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) > > Do we need a "#define IOMAP_NULL 0" type to make this more explicit? > > Or at least a comment in iomap.h above the IOMAP_HOLE definition > pointing out that type == 0 is valid for srcmap and not valid for iomap? > > Other than that the rest looks ok. FWIW, my opinions about this have evolved since two days ago; please see my reply to patch #12 about initializing @srcmap.type = IOMAP_HOLE and using "type == IOMAP_HOLE" to decide if we're going to use the srcmap for anything. --D > --D > > (This reminds me that at some point I ought to work on iomap debugging > checks for the mappings returned by ->iomap_begin ...) > > > + 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 ? &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 a421977a9496..58fb7a894ad4 100644 > > --- a/fs/iomap/buffered-io.c > > +++ b/fs/iomap/buffered-io.c > > @@ -219,7 +219,7 @@ 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; > > @@ -367,7 +367,7 @@ 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; > > @@ -387,7 +387,7 @@ 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; > > @@ -567,7 +567,7 @@ 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); > > @@ -590,7 +590,7 @@ __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); > > @@ -599,7 +599,7 @@ __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); > > @@ -609,13 +609,15 @@ __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; > > @@ -633,13 +635,13 @@ 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; > > @@ -725,16 +727,16 @@ 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 { > > @@ -765,7 +767,7 @@ 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; > > @@ -799,7 +801,8 @@ 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; > > > > @@ -810,8 +813,8 @@ 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; > > @@ -864,7 +867,7 @@ 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; > > @@ -873,7 +876,7 @@ 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 { > > @@ -882,11 +885,12 @@ 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; > > @@ -925,19 +929,19 @@ 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, > > @@ -949,14 +953,14 @@ 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 { > > @@ -968,7 +972,8 @@ 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; > > > > @@ -1018,7 +1023,7 @@ 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 d340db666c06..f1c3ff27c666 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 3a0f0975a57e..6d795924baa7 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 > >
diff --git a/fs/dax.c b/fs/dax.c index a237141d8787..8016be24bbd9 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 = { 0 }; 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 = { 0 }; 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 420fe3deed39..e2116e8228d2 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3453,7 +3453,7 @@ 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 79581b9bdebb..0bf8e8fa82bd 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1123,7 +1123,8 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, } 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..67efd86675e6 100644 --- a/fs/iomap/apply.c +++ b/fs/iomap/apply.c @@ -24,7 +24,9 @@ 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 srcmap = { 0 }; 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) + 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 ? &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 a421977a9496..58fb7a894ad4 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -219,7 +219,7 @@ 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; @@ -367,7 +367,7 @@ 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; @@ -387,7 +387,7 @@ 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; @@ -567,7 +567,7 @@ 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); @@ -590,7 +590,7 @@ __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); @@ -599,7 +599,7 @@ __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); @@ -609,13 +609,15 @@ __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; @@ -633,13 +635,13 @@ 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; @@ -725,16 +727,16 @@ 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 { @@ -765,7 +767,7 @@ 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; @@ -799,7 +801,8 @@ 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; @@ -810,8 +813,8 @@ 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; @@ -864,7 +867,7 @@ 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; @@ -873,7 +876,7 @@ 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 { @@ -882,11 +885,12 @@ 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; @@ -925,19 +929,19 @@ 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, @@ -949,14 +953,14 @@ 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 { @@ -968,7 +972,8 @@ 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; @@ -1018,7 +1023,7 @@ 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 d340db666c06..f1c3ff27c666 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 3a0f0975a57e..6d795924baa7 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,