On Mon, Jul 19, 2021 at 12:35:16PM +0200, Christoph Hellwig wrote:
> Instead of another internal flags namespace inside of buffered-io.c,
> just pass a UNSHARE hint in the main iomap flags field.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/iomap/buffered-io.c | 23 +++++++++--------------
> include/linux/iomap.h | 1 +
> 2 files changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index daabbe8d7edfb5..eb5d742b5bf8b7 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -511,10 +511,6 @@ iomap_migrate_page(struct address_space *mapping, struct page *newpage,
> EXPORT_SYMBOL_GPL(iomap_migrate_page);
> #endif /* CONFIG_MIGRATION */
>
> -enum {
> - IOMAP_WRITE_F_UNSHARE = (1 << 0),
> -};
Oh good, this finally dies.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> -
> static void
> iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
> {
> @@ -544,7 +540,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff,
> }
>
> static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,
> - unsigned len, int flags, struct page *page)
> + unsigned len, struct page *page)
> {
> struct iomap *srcmap = iomap_iter_srcmap(iter);
> struct iomap_page *iop = iomap_page_create(iter->inode, page);
> @@ -563,13 +559,13 @@ static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,
> if (plen == 0)
> break;
>
> - if (!(flags & IOMAP_WRITE_F_UNSHARE) &&
> + if (!(iter->flags & IOMAP_UNSHARE) &&
> (from <= poff || from >= poff + plen) &&
> (to <= poff || to >= poff + plen))
> continue;
>
> if (iomap_block_needs_zeroing(iter, block_start)) {
> - if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE))
> + if (WARN_ON_ONCE(iter->flags & IOMAP_UNSHARE))
> return -EIO;
> zero_user_segments(page, poff, from, to, poff + plen);
> } else {
> @@ -585,7 +581,7 @@ static int __iomap_write_begin(struct iomap_iter *iter, loff_t pos,
> }
>
> static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len,
> - unsigned flags, struct page **pagep)
> + struct page **pagep)
> {
> const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
> struct iomap *srcmap = iomap_iter_srcmap(iter);
> @@ -617,7 +613,7 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, unsigned len,
> else if (iter->iomap.flags & IOMAP_F_BUFFER_HEAD)
> status = __block_write_begin_int(page, pos, len, NULL, srcmap);
> else
> - status = __iomap_write_begin(iter, pos, len, flags, page);
> + status = __iomap_write_begin(iter, pos, len, page);
>
> if (unlikely(status))
> goto out_unlock;
> @@ -748,7 +744,7 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i)
> break;
> }
>
> - status = iomap_write_begin(iter, pos, bytes, 0, &page);
> + status = iomap_write_begin(iter, pos, bytes, &page);
> if (unlikely(status))
> break;
>
> @@ -825,8 +821,7 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)
> unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length);
> struct page *page;
>
> - status = iomap_write_begin(iter, pos, bytes,
> - IOMAP_WRITE_F_UNSHARE, &page);
> + status = iomap_write_begin(iter, pos, bytes, &page);
> if (unlikely(status))
> return status;
>
> @@ -854,7 +849,7 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
> .inode = inode,
> .pos = pos,
> .len = len,
> - .flags = IOMAP_WRITE,
> + .flags = IOMAP_WRITE | IOMAP_UNSHARE,
> };
> int ret;
>
> @@ -871,7 +866,7 @@ static s64 __iomap_zero_iter(struct iomap_iter *iter, loff_t pos, u64 length)
> unsigned offset = offset_in_page(pos);
> unsigned bytes = min_t(u64, PAGE_SIZE - offset, length);
>
> - status = iomap_write_begin(iter, pos, bytes, 0, &page);
> + status = iomap_write_begin(iter, pos, bytes, &page);
> if (status)
> return status;
>
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 2f13e34c2c0b0b..719798814bdfdb 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -122,6 +122,7 @@ struct iomap_page_ops {
> #define IOMAP_DIRECT (1 << 4) /* direct I/O */
> #define IOMAP_NOWAIT (1 << 5) /* do not block */
> #define IOMAP_OVERWRITE_ONLY (1 << 6) /* only pure overwrites allowed */
> +#define IOMAP_UNSHARE (1 << 7) /* unshare_file_range */
>
> struct iomap_ops {
> /*
> --
> 2.30.2
>
