On Mon, Sep 09, 2019 at 08:27:18PM +0200, Christoph Hellwig wrote:
> Move xfs_file_iomap_begin_delay near the end of the file next to the
> other iomap functions to prepare for additional refactoring.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/xfs/xfs_iomap.c | 434 +++++++++++++++++++++++----------------------
> 1 file changed, 221 insertions(+), 213 deletions(-)
>
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index d0ed0cba9041..7ae55503ee27 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -530,219 +530,6 @@ xfs_iomap_prealloc_size(
> return alloc_blocks;
> }
>
> -static int
> -xfs_file_iomap_begin_delay(
> - struct inode *inode,
> - loff_t offset,
> - loff_t count,
> - unsigned flags,
> - struct iomap *iomap,
> - struct iomap *srcmap)
> -{
> - struct xfs_inode *ip = XFS_I(inode);
> - struct xfs_mount *mp = ip->i_mount;
> - xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
> - xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, count);
> - struct xfs_bmbt_irec imap, cmap;
> - struct xfs_iext_cursor icur, ccur;
> - xfs_fsblock_t prealloc_blocks = 0;
> - bool eof = false, cow_eof = false, shared = false;
> - int whichfork = XFS_DATA_FORK;
> - int error = 0;
> -
> - ASSERT(!XFS_IS_REALTIME_INODE(ip));
> - ASSERT(!xfs_get_extsz_hint(ip));
> -
> - xfs_ilock(ip, XFS_ILOCK_EXCL);
> -
> - if (unlikely(XFS_TEST_ERROR(
> - (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
> - XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
> - mp, XFS_ERRTAG_BMAPIFORMAT))) {
> - XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
> - error = -EFSCORRUPTED;
> - goto out_unlock;
> - }
> -
> - XFS_STATS_INC(mp, xs_blk_mapw);
> -
> - if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) {
> - error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
> - if (error)
> - goto out_unlock;
> - }
> -
> - /*
> - * Search the data fork fork first to look up our source mapping. We
> - * always need the data fork map, as we have to return it to the
> - * iomap code so that the higher level write code can read data in to
> - * perform read-modify-write cycles for unaligned writes.
> - */
> - eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap);
> - if (eof)
> - imap.br_startoff = end_fsb; /* fake hole until the end */
> -
> - /* We never need to allocate blocks for zeroing a hole. */
> - if ((flags & IOMAP_ZERO) && imap.br_startoff > offset_fsb) {
> - xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff);
> - goto out_unlock;
> - }
> -
> - /*
> - * Search the COW fork extent list even if we did not find a data fork
> - * extent. This serves two purposes: first this implements the
> - * speculative preallocation using cowextsize, so that we also unshare
> - * block adjacent to shared blocks instead of just the shared blocks
> - * themselves. Second the lookup in the extent list is generally faster
> - * than going out to the shared extent tree.
> - */
> - if (xfs_is_cow_inode(ip)) {
> - if (!ip->i_cowfp) {
> - ASSERT(!xfs_is_reflink_inode(ip));
> - xfs_ifork_init_cow(ip);
> - }
> - cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb,
> - &ccur, &cmap);
> - if (!cow_eof && cmap.br_startoff <= offset_fsb) {
> - trace_xfs_reflink_cow_found(ip, &cmap);
> - goto found_cow;
> - }
> - }
> -
> - if (imap.br_startoff <= offset_fsb) {
> - /*
> - * For reflink files we may need a delalloc reservation when
> - * overwriting shared extents. This includes zeroing of
> - * existing extents that contain data.
> - */
> - if (!xfs_is_cow_inode(ip) ||
> - ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {
> - trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
> - &imap);
> - goto found_imap;
> - }
> -
> - xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
> -
> - /* Trim the mapping to the nearest shared extent boundary. */
> - error = xfs_inode_need_cow(ip, &imap, &shared);
> - if (error)
> - goto out_unlock;
> -
> - /* Not shared? Just report the (potentially capped) extent. */
> - if (!shared) {
> - trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
> - &imap);
> - goto found_imap;
> - }
> -
> - /*
> - * Fork all the shared blocks from our write offset until the
> - * end of the extent.
> - */
> - whichfork = XFS_COW_FORK;
> - end_fsb = imap.br_startoff + imap.br_blockcount;
> - } else {
> - /*
> - * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
> - * pages to keep the chunks of work done where somewhat
> - * symmetric with the work writeback does. This is a completely
> - * arbitrary number pulled out of thin air.
> - *
> - * Note that the values needs to be less than 32-bits wide until
> - * the lower level functions are updated.
> - */
> - count = min_t(loff_t, count, 1024 * PAGE_SIZE);
> - end_fsb = xfs_iomap_end_fsb(mp, offset, count);
> -
> - if (xfs_is_always_cow_inode(ip))
> - whichfork = XFS_COW_FORK;
> - }
> -
> - error = xfs_qm_dqattach_locked(ip, false);
> - if (error)
> - goto out_unlock;
> -
> - if (eof) {
> - prealloc_blocks = xfs_iomap_prealloc_size(ip, whichfork, offset,
> - count, &icur);
> - if (prealloc_blocks) {
> - xfs_extlen_t align;
> - xfs_off_t end_offset;
> - xfs_fileoff_t p_end_fsb;
> -
> - end_offset = XFS_WRITEIO_ALIGN(mp, offset + count - 1);
> - p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
> - prealloc_blocks;
> -
> - align = xfs_eof_alignment(ip, 0);
> - if (align)
> - p_end_fsb = roundup_64(p_end_fsb, align);
> -
> - p_end_fsb = min(p_end_fsb,
> - XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> - ASSERT(p_end_fsb > offset_fsb);
> - prealloc_blocks = p_end_fsb - end_fsb;
> - }
> - }
> -
> -retry:
> - error = xfs_bmapi_reserve_delalloc(ip, whichfork, offset_fsb,
> - end_fsb - offset_fsb, prealloc_blocks,
> - whichfork == XFS_DATA_FORK ? &imap : &cmap,
> - whichfork == XFS_DATA_FORK ? &icur : &ccur,
> - whichfork == XFS_DATA_FORK ? eof : cow_eof);
> - switch (error) {
> - case 0:
> - break;
> - case -ENOSPC:
> - case -EDQUOT:
> - /* retry without any preallocation */
> - trace_xfs_delalloc_enospc(ip, offset, count);
> - if (prealloc_blocks) {
> - prealloc_blocks = 0;
> - goto retry;
> - }
> - /*FALLTHRU*/
> - default:
> - goto out_unlock;
> - }
> -
> - if (whichfork == XFS_COW_FORK) {
> - trace_xfs_iomap_alloc(ip, offset, count, whichfork, &cmap);
> - goto found_cow;
> - }
> -
> - /*
> - * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
> - * them out if the write happens to fail.
> - */
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> - trace_xfs_iomap_alloc(ip, offset, count, whichfork, &imap);
> - return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_NEW);
> -
> -found_imap:
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> - return xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
> -
> -found_cow:
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> - if (imap.br_startoff <= offset_fsb) {
> - error = xfs_bmbt_to_iomap(ip, srcmap, &imap, 0);
> - if (error)
> - return error;
> - } else {
> - xfs_trim_extent(&cmap, offset_fsb,
> - imap.br_startoff - offset_fsb);
> - }
> - return xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
> -
> -out_unlock:
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> - return error;
> -
> -}
> -
> int
> xfs_iomap_write_unwritten(
> xfs_inode_t *ip,
> @@ -931,6 +718,15 @@ xfs_ilock_for_iomap(
> return 0;
> }
>
> +static int
> +xfs_file_iomap_begin_delay(
> + struct inode *inode,
> + loff_t offset,
> + loff_t count,
> + unsigned flags,
> + struct iomap *iomap,
> + struct iomap *srcmap);
> +
> static int
> xfs_file_iomap_begin(
> struct inode *inode,
> @@ -1061,6 +857,218 @@ xfs_file_iomap_begin(
> return error;
> }
>
> +static int
> +xfs_file_iomap_begin_delay(
> + struct inode *inode,
> + loff_t offset,
> + loff_t count,
> + unsigned flags,
> + struct iomap *iomap,
> + struct iomap *srcmap)
> +{
> + struct xfs_inode *ip = XFS_I(inode);
> + struct xfs_mount *mp = ip->i_mount;
> + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
> + xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, count);
> + struct xfs_bmbt_irec imap, cmap;
> + struct xfs_iext_cursor icur, ccur;
> + xfs_fsblock_t prealloc_blocks = 0;
> + bool eof = false, cow_eof = false, shared = false;
> + int whichfork = XFS_DATA_FORK;
> + int error = 0;
> +
> + ASSERT(!XFS_IS_REALTIME_INODE(ip));
> + ASSERT(!xfs_get_extsz_hint(ip));
> +
> + xfs_ilock(ip, XFS_ILOCK_EXCL);
> +
> + if (unlikely(XFS_TEST_ERROR(
> + (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
> + XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
> + mp, XFS_ERRTAG_BMAPIFORMAT))) {
> + XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
> + error = -EFSCORRUPTED;
> + goto out_unlock;
> + }
> +
> + XFS_STATS_INC(mp, xs_blk_mapw);
> +
> + if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) {
> + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
> + if (error)
> + goto out_unlock;
> + }
> +
> + /*
> + * Search the data fork fork first to look up our source mapping. We
> + * always need the data fork map, as we have to return it to the
> + * iomap code so that the higher level write code can read data in to
> + * perform read-modify-write cycles for unaligned writes.
> + */
> + eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap);
> + if (eof)
> + imap.br_startoff = end_fsb; /* fake hole until the end */
> +
> + /* We never need to allocate blocks for zeroing a hole. */
> + if ((flags & IOMAP_ZERO) && imap.br_startoff > offset_fsb) {
> + xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff);
> + goto out_unlock;
> + }
> +
> + /*
> + * Search the COW fork extent list even if we did not find a data fork
> + * extent. This serves two purposes: first this implements the
> + * speculative preallocation using cowextsize, so that we also unshare
> + * block adjacent to shared blocks instead of just the shared blocks
> + * themselves. Second the lookup in the extent list is generally faster
> + * than going out to the shared extent tree.
> + */
> + if (xfs_is_cow_inode(ip)) {
> + if (!ip->i_cowfp) {
> + ASSERT(!xfs_is_reflink_inode(ip));
> + xfs_ifork_init_cow(ip);
> + }
> + cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb,
> + &ccur, &cmap);
> + if (!cow_eof && cmap.br_startoff <= offset_fsb) {
> + trace_xfs_reflink_cow_found(ip, &cmap);
> + goto found_cow;
> + }
> + }
> +
> + if (imap.br_startoff <= offset_fsb) {
> + /*
> + * For reflink files we may need a delalloc reservation when
> + * overwriting shared extents. This includes zeroing of
> + * existing extents that contain data.
> + */
> + if (!xfs_is_cow_inode(ip) ||
> + ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) {
> + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
> + &imap);
> + goto found_imap;
> + }
> +
> + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb);
> +
> + /* Trim the mapping to the nearest shared extent boundary. */
> + error = xfs_inode_need_cow(ip, &imap, &shared);
> + if (error)
> + goto out_unlock;
> +
> + /* Not shared? Just report the (potentially capped) extent. */
> + if (!shared) {
> + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK,
> + &imap);
> + goto found_imap;
> + }
> +
> + /*
> + * Fork all the shared blocks from our write offset until the
> + * end of the extent.
> + */
> + whichfork = XFS_COW_FORK;
> + end_fsb = imap.br_startoff + imap.br_blockcount;
> + } else {
> + /*
> + * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
> + * pages to keep the chunks of work done where somewhat
> + * symmetric with the work writeback does. This is a completely
> + * arbitrary number pulled out of thin air.
> + *
> + * Note that the values needs to be less than 32-bits wide until
> + * the lower level functions are updated.
> + */
> + count = min_t(loff_t, count, 1024 * PAGE_SIZE);
> + end_fsb = xfs_iomap_end_fsb(mp, offset, count);
> +
> + if (xfs_is_always_cow_inode(ip))
> + whichfork = XFS_COW_FORK;
> + }
> +
> + error = xfs_qm_dqattach_locked(ip, false);
> + if (error)
> + goto out_unlock;
> +
> + if (eof) {
> + prealloc_blocks = xfs_iomap_prealloc_size(ip, whichfork, offset,
> + count, &icur);
> + if (prealloc_blocks) {
> + xfs_extlen_t align;
> + xfs_off_t end_offset;
> + xfs_fileoff_t p_end_fsb;
> +
> + end_offset = XFS_WRITEIO_ALIGN(mp, offset + count - 1);
> + p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
> + prealloc_blocks;
> +
> + align = xfs_eof_alignment(ip, 0);
> + if (align)
> + p_end_fsb = roundup_64(p_end_fsb, align);
> +
> + p_end_fsb = min(p_end_fsb,
> + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
Might as well fix the indenting damage here?
With that fixed,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> + ASSERT(p_end_fsb > offset_fsb);
> + prealloc_blocks = p_end_fsb - end_fsb;
> + }
> + }
> +
> +retry:
> + error = xfs_bmapi_reserve_delalloc(ip, whichfork, offset_fsb,
> + end_fsb - offset_fsb, prealloc_blocks,
> + whichfork == XFS_DATA_FORK ? &imap : &cmap,
> + whichfork == XFS_DATA_FORK ? &icur : &ccur,
> + whichfork == XFS_DATA_FORK ? eof : cow_eof);
> + switch (error) {
> + case 0:
> + break;
> + case -ENOSPC:
> + case -EDQUOT:
> + /* retry without any preallocation */
> + trace_xfs_delalloc_enospc(ip, offset, count);
> + if (prealloc_blocks) {
> + prealloc_blocks = 0;
> + goto retry;
> + }
> + /*FALLTHRU*/
> + default:
> + goto out_unlock;
> + }
> +
> + if (whichfork == XFS_COW_FORK) {
> + trace_xfs_iomap_alloc(ip, offset, count, whichfork, &cmap);
> + goto found_cow;
> + }
> +
> + /*
> + * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
> + * them out if the write happens to fail.
> + */
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> + trace_xfs_iomap_alloc(ip, offset, count, whichfork, &imap);
> + return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_NEW);
> +
> +found_imap:
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> + return xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
> +
> +found_cow:
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> + if (imap.br_startoff <= offset_fsb) {
> + error = xfs_bmbt_to_iomap(ip, srcmap, &imap, 0);
> + if (error)
> + return error;
> + } else {
> + xfs_trim_extent(&cmap, offset_fsb,
> + imap.br_startoff - offset_fsb);
> + }
> + return xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
> +
> +out_unlock:
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> + return error;
> +}
> +
> static int
> xfs_file_iomap_end_delalloc(
> struct xfs_inode *ip,
> --
> 2.20.1
>
