On Tue, Sep 28, 2021 at 02:23:10PM +0800, Shiyang Ruan wrote:
> In fsdax mode, WRITE and ZERO on a shared extent need CoW performed.
> After that, new allocated extents needs to be remapped to the file.
> So, add a CoW identification in ->iomap_begin(), and implement
> ->iomap_end() to do the remapping work.
>
> Signed-off-by: Shiyang Ruan <ruansy.f...@fujitsu.com>
I think this patch looks good, so:
Reviewed-by: Darrick J. Wong <djw...@kernel.org>
A big thank you to Shiyang for persisting in getting this series
finished! :)
Judging from the conversation Christoph and I had the last time this
patchset was submitted, I gather the last big remaining issue is the use
of page->mapping for hw poison. So I'll go take a look at "fsdax:
introduce FS query interface to support reflink" now.
--D
> ---
> fs/xfs/xfs_bmap_util.c | 3 +--
> fs/xfs/xfs_file.c | 7 ++-----
> fs/xfs/xfs_iomap.c | 30 +++++++++++++++++++++++++++-
> fs/xfs/xfs_iomap.h | 44 ++++++++++++++++++++++++++++++++++++++++++
> fs/xfs/xfs_iops.c | 7 +++----
> fs/xfs/xfs_reflink.c | 3 +--
> 6 files changed, 80 insertions(+), 14 deletions(-)
>
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index 73a36b7be3bd..0681250e0a5d 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -1009,8 +1009,7 @@ xfs_free_file_space(
> return 0;
> if (offset + len > XFS_ISIZE(ip))
> len = XFS_ISIZE(ip) - offset;
> - error = iomap_zero_range(VFS_I(ip), offset, len, NULL,
> - &xfs_buffered_write_iomap_ops);
> + error = xfs_iomap_zero_range(ip, offset, len, NULL);
> if (error)
> return error;
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7aa943edfc02..afde4fbefb6f 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -704,7 +704,7 @@ xfs_file_dax_write(
> pos = iocb->ki_pos;
>
> trace_xfs_file_dax_write(iocb, from);
> - ret = dax_iomap_rw(iocb, from, &xfs_direct_write_iomap_ops);
> + ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops);
> if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
> i_size_write(inode, iocb->ki_pos);
> error = xfs_setfilesize(ip, pos, ret);
> @@ -1327,10 +1327,7 @@ __xfs_filemap_fault(
> pfn_t pfn;
>
> xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
> - ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL,
> - (write_fault && !vmf->cow_page) ?
> - &xfs_direct_write_iomap_ops :
> - &xfs_read_iomap_ops);
> + ret = xfs_dax_iomap_fault(vmf, pe_size, write_fault, &pfn);
> if (ret & VM_FAULT_NEEDDSYNC)
> ret = dax_finish_sync_fault(vmf, pe_size, pfn);
> xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 093758440ad5..51cb5b713521 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -761,7 +761,8 @@ xfs_direct_write_iomap_begin(
>
> /* may drop and re-acquire the ilock */
> error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
> - &lockmode, flags & IOMAP_DIRECT);
> + &lockmode,
> + (flags & IOMAP_DIRECT) || IS_DAX(inode));
> if (error)
> goto out_unlock;
> if (shared)
> @@ -854,6 +855,33 @@ const struct iomap_ops xfs_direct_write_iomap_ops = {
> .iomap_begin = xfs_direct_write_iomap_begin,
> };
>
> +static int
> +xfs_dax_write_iomap_end(
> + struct inode *inode,
> + loff_t pos,
> + loff_t length,
> + ssize_t written,
> + unsigned flags,
> + struct iomap *iomap)
> +{
> + struct xfs_inode *ip = XFS_I(inode);
> +
> + if (!xfs_is_cow_inode(ip))
> + return 0;
> +
> + if (!written) {
> + xfs_reflink_cancel_cow_range(ip, pos, length, true);
> + return 0;
> + }
> +
> + return xfs_reflink_end_cow(ip, pos, written);
> +}
> +
> +const struct iomap_ops xfs_dax_write_iomap_ops = {
> + .iomap_begin = xfs_direct_write_iomap_begin,
> + .iomap_end = xfs_dax_write_iomap_end,
> +};
> +
> static int
> xfs_buffered_write_iomap_begin(
> struct inode *inode,
> diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h
> index 7d3703556d0e..81726bfbf890 100644
> --- a/fs/xfs/xfs_iomap.h
> +++ b/fs/xfs/xfs_iomap.h
> @@ -7,6 +7,7 @@
> #define __XFS_IOMAP_H__
>
> #include <linux/iomap.h>
> +#include <linux/dax.h>
>
> struct xfs_inode;
> struct xfs_bmbt_irec;
> @@ -45,5 +46,48 @@ extern const struct iomap_ops xfs_direct_write_iomap_ops;
> extern const struct iomap_ops xfs_read_iomap_ops;
> extern const struct iomap_ops xfs_seek_iomap_ops;
> extern const struct iomap_ops xfs_xattr_iomap_ops;
> +extern const struct iomap_ops xfs_dax_write_iomap_ops;
> +
> +static inline int
> +xfs_iomap_zero_range(
> + struct xfs_inode *ip,
> + loff_t pos,
> + loff_t len,
> + bool *did_zero)
> +{
> + struct inode *inode = VFS_I(ip);
> +
> + return iomap_zero_range(inode, pos, len, did_zero,
> + IS_DAX(inode) ?
> + &xfs_dax_write_iomap_ops :
> + &xfs_buffered_write_iomap_ops);
> +}
> +
> +static inline int
> +xfs_iomap_truncate_page(
> + struct xfs_inode *ip,
> + loff_t pos,
> + bool *did_zero)
> +{
> + struct inode *inode = VFS_I(ip);
> +
> + return iomap_truncate_page(inode, pos, did_zero,
> + IS_DAX(inode) ?
> + &xfs_dax_write_iomap_ops :
> + &xfs_buffered_write_iomap_ops);
> +}
> +
> +static inline int
> +xfs_dax_iomap_fault(
> + struct vm_fault *vmf,
> + enum page_entry_size pe_size,
> + bool write_fault,
> + pfn_t *pfn)
> +{
> + return dax_iomap_fault(vmf, pe_size, pfn, NULL,
> + (write_fault && !vmf->cow_page) ?
> + &xfs_dax_write_iomap_ops :
> + &xfs_read_iomap_ops);
> +}
>
> #endif /* __XFS_IOMAP_H__*/
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index a607d6aca5c4..332e6208dffd 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -911,8 +911,8 @@ xfs_setattr_size(
> */
> if (newsize > oldsize) {
> trace_xfs_zero_eof(ip, oldsize, newsize - oldsize);
> - error = iomap_zero_range(inode, oldsize, newsize - oldsize,
> - &did_zeroing, &xfs_buffered_write_iomap_ops);
> + error = xfs_iomap_zero_range(ip, oldsize, newsize - oldsize,
> + &did_zeroing);
> } else {
> /*
> * iomap won't detect a dirty page over an unwritten block (or a
> @@ -924,8 +924,7 @@ xfs_setattr_size(
> newsize);
> if (error)
> return error;
> - error = iomap_truncate_page(inode, newsize, &did_zeroing,
> - &xfs_buffered_write_iomap_ops);
> + error = xfs_iomap_truncate_page(ip, newsize, &did_zeroing);
> }
>
> if (error)
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index 7ecea0311e88..9d876e268734 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1269,8 +1269,7 @@ xfs_reflink_zero_posteof(
> return 0;
>
> trace_xfs_zero_eof(ip, isize, pos - isize);
> - return iomap_zero_range(VFS_I(ip), isize, pos - isize, NULL,
> - &xfs_buffered_write_iomap_ops);
> + return xfs_iomap_zero_range(ip, isize, pos - isize, NULL);
> }
>
> /*
> --
> 2.33.0
>
>
>
