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xfs: optimize xfs_reflink_cancel_cow_blocks

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Rewrite xfs_reflink_cancel_cow_blocks so that we only do a search for
the first extent in the extent list and then iterate over the remaining
extents using the extent index, passing the extent we operate on
directly to xfs_bmap_del_extent_delay or xfs_bmap_del_extent_cow instead
of going through xfs_bunmapi and doing yet another extent list lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Christoph Hellwig 2016-10-20 15:54:31 +11:00 committed by Dave Chinner
parent fa5c836ca8
commit 3e0ee78f7a
1 changed files with 23 additions and 28 deletions
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51
fs/xfs/xfs_reflink.c
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@ -511,53 +511,49 @@ xfs_reflink_cancel_cow_blocks(
xfs_fileoff_t offset_fsb,
xfs_fileoff_t end_fsb)
{
struct xfs_bmbt_irec irec;
xfs_filblks_t count_fsb;
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
struct xfs_bmbt_irec got, prev, del;
xfs_extnum_t idx;
xfs_fsblock_t firstfsb;
struct xfs_defer_ops dfops;
int error = 0;
int nimaps;
int error = 0, eof = 0;
if (!xfs_is_reflink_inode(ip))
return 0;
/* Go find the old extent in the CoW fork. */
while (offset_fsb < end_fsb) {
nimaps = 1;
count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
error = xfs_bmapi_read(ip, offset_fsb, count_fsb, &irec,
&nimaps, XFS_BMAPI_COWFORK);
if (error)
break;
ASSERT(nimaps == 1);
xfs_bmap_search_extents(ip, offset_fsb, XFS_COW_FORK, &eof, &idx,
&got, &prev);
if (eof)
return 0;
trace_xfs_reflink_cancel_cow(ip, &irec);
while (got.br_startoff < end_fsb) {
del = got;
xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
trace_xfs_reflink_cancel_cow(ip, &del);
if (irec.br_startblock == DELAYSTARTBLOCK) {
/* Remove the mapping from the CoW fork. */
error = xfs_bunmapi_cow(ip, &irec);
if (isnullstartblock(del.br_startblock)) {
error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK,
&idx, &got, &del);
if (error)
break;
} else if (irec.br_startblock == HOLESTARTBLOCK) {
/* empty */
} else {
xfs_trans_ijoin(*tpp, ip, 0);
xfs_defer_init(&dfops, &firstfsb);
/* Free the CoW orphan record. */
error = xfs_refcount_free_cow_extent(ip->i_mount,
&dfops, irec.br_startblock,
irec.br_blockcount);
&dfops, del.br_startblock,
del.br_blockcount);
if (error)
break;
xfs_bmap_add_free(ip->i_mount, &dfops,
irec.br_startblock, irec.br_blockcount,
del.br_startblock, del.br_blockcount,
NULL);
/* Update quota accounting */
xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT,
-(long)irec.br_blockcount);
-(long)del.br_blockcount);
/* Roll the transaction */
error = xfs_defer_finish(tpp, &dfops, ip);
@ -567,13 +563,12 @@ xfs_reflink_cancel_cow_blocks(
}
/* Remove the mapping from the CoW fork. */
error = xfs_bunmapi_cow(ip, &irec);
if (error)
break;
xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
}
/* Roll on... */
offset_fsb = irec.br_startoff + irec.br_blockcount;
if (++idx >= ifp->if_bytes / sizeof(struct xfs_bmbt_rec))
return 0;
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got);
}
return error;