When we allocate COW fork blocks for direct I/O writes we currently first
create a delayed allocation, and then convert it to a real allocation
once we've got the delayed one.
As there is no good reason for that this patch instead makes use call
xfs_bmapi_write from the COW allocation path. The only interesting bits
are a few tweaks the low-level allocator to allow for this, most notably
the need to remove the call to xfs_bmap_extsize_align for the cowextsize
in xfs_bmap_btalloc - for the existing convert case it's a no-op, but
for the direct allocation case it would blow up our block reservation
way beyond what we reserved for the transaction.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/libxfs/xfs_bmap.c | 9 ++---
fs/xfs/xfs_reflink.c | 101 ++++++++++++++++++++++++++++++++++-------------
2 files changed, 76 insertions(+), 34 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 6f28814..a4a4327 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -2893,13 +2893,14 @@ xfs_bmap_add_extent_hole_real(
ASSERT(!isnullstartblock(new->br_startblock));
ASSERT(!bma->cur ||
!(bma->cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
- ASSERT(whichfork != XFS_COW_FORK);
XFS_STATS_INC(mp, xs_add_exlist);
state = 0;
if (whichfork == XFS_ATTR_FORK)
state |= BMAP_ATTRFORK;
+ if (whichfork == XFS_COW_FORK)
+ state |= BMAP_COWFORK;
/*
* Check and set flags if this segment has a left neighbor.
@@ -3619,9 +3620,7 @@ xfs_bmap_btalloc(
else if (mp->m_dalign)
stripe_align = mp->m_dalign;
- if (ap->flags & XFS_BMAPI_COWFORK)
- align = xfs_get_cowextsz_hint(ap->ip);
- else if (xfs_alloc_is_userdata(ap->datatype))
+ if (xfs_alloc_is_userdata(ap->datatype))
align = xfs_get_extsz_hint(ap->ip);
if (unlikely(align)) {
error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
@@ -4608,8 +4607,6 @@ xfs_bmapi_write(
*/
if (flags & XFS_BMAPI_REMAP)
ASSERT(inhole);
- if (flags & XFS_BMAPI_COWFORK)
- ASSERT(!inhole);
/*
* First, deal with the hole before the allocated space
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 88fd03c..0a077e80 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -304,59 +304,104 @@ __xfs_reflink_allocate_cow(
xfs_fileoff_t end_fsb)
{
struct xfs_mount *mp = ip->i_mount;
- struct xfs_bmbt_irec imap;
+ struct xfs_bmbt_irec imap, got;
struct xfs_defer_ops dfops;
struct xfs_trans *tp;
xfs_fsblock_t first_block;
- int nimaps = 1, error;
- bool shared;
+ int nimaps, error, lockmode;
+ bool shared, trimmed;
+ xfs_extlen_t resblks, align;
+ xfs_extnum_t idx;
- xfs_defer_init(&dfops, &first_block);
+ align = xfs_eof_alignment(ip, xfs_get_cowextsz_hint(ip));
+ if (align)
+ end_fsb = roundup_64(end_fsb, align);
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
- XFS_TRANS_RESERVE, &tp);
+ resblks = XFS_DIOSTRAT_SPACE_RES(mp, end_fsb - *offset_fsb);
+
+ error = xfs_qm_dqattach(ip, 0);
if (error)
return error;
- xfs_ilock(ip, XFS_ILOCK_EXCL);
-
- /* Read extent from the source file. */
- nimaps = 1;
- error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb,
- &imap, &nimaps, 0);
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
if (error)
- goto out_unlock;
- ASSERT(nimaps == 1);
+ return error;
- error = xfs_reflink_reserve_cow(ip, &imap, &shared);
- if (error)
- goto out_trans_cancel;
+ lockmode = XFS_ILOCK_EXCL;
+ xfs_ilock(ip, lockmode);
- if (!shared) {
- *offset_fsb = imap.br_startoff + imap.br_blockcount;
- goto out_trans_cancel;
+ /*
+ * Even if the extent is not shared we might have a preallocation for
+ * it in the COW fork. If so use it.
+ */
+ if (xfs_iext_lookup_extent(ip, ip->i_cowfp, *offset_fsb, &idx, &got) &&
+ got.br_startoff <= *offset_fsb) {
+ /* If we have a real allocation in the COW fork we're done. */
+ if (!isnullstartblock(got.br_startblock)) {
+ xfs_trim_extent(&got, *offset_fsb,
+ end_fsb - *offset_fsb);
+ *offset_fsb = got.br_startoff + got.br_blockcount;
+ goto out_trans_cancel;
+ }
+ } else {
+ nimaps = 1;
+ error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb,
+ &imap, &nimaps, 0);
+ if (error)
+ goto out_trans_cancel;
+ ASSERT(nimaps == 1);
+
+ /* Trim the mapping to the nearest shared extent boundary. */
+ error = xfs_reflink_trim_around_shared(ip, &imap, &shared,
+ &trimmed);
+ if (error)
+ goto out_trans_cancel;
+
+ if (!shared) {
+ *offset_fsb = imap.br_startoff + imap.br_blockcount;
+ goto out_trans_cancel;
+ }
+
+ *offset_fsb = imap.br_startoff;
+ end_fsb = imap.br_startoff + imap.br_blockcount;
+ if (align)
+ end_fsb = roundup_64(end_fsb, align);
}
- xfs_trans_ijoin(tp, ip, 0);
- error = xfs_bmapi_write(tp, ip, imap.br_startoff, imap.br_blockcount,
- XFS_BMAPI_COWFORK, &first_block,
- XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK),
- &imap, &nimaps, &dfops);
+ error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
+ XFS_QMOPT_RES_REGBLKS);
if (error)
goto out_trans_cancel;
+ xfs_trans_ijoin(tp, ip, 0);
+
+ xfs_defer_init(&dfops, &first_block);
+ nimaps = 1;
+ error = xfs_bmapi_write(tp, ip, *offset_fsb, end_fsb - *offset_fsb,
+ XFS_BMAPI_COWFORK, &first_block, resblks, &imap,
+ &nimaps, &dfops);
+ if (error)
+ goto out_bmap_cancel;
+
error = xfs_defer_finish(&tp, &dfops, NULL);
if (error)
- goto out_trans_cancel;
+ goto out_bmap_cancel;
error = xfs_trans_commit(tp);
+ if (error)
+ goto out_unlock;
*offset_fsb = imap.br_startoff + imap.br_blockcount;
+
out_unlock:
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ xfs_iunlock(ip, lockmode);
return error;
-out_trans_cancel:
+
+out_bmap_cancel:
xfs_defer_cancel(&dfops);
+ xfs_trans_unreserve_quota_nblks(tp, ip, (long)resblks, 0,
+ XFS_QMOPT_RES_REGBLKS);
+out_trans_cancel:
xfs_trans_cancel(tp);
goto out_unlock;
}
--
2.1.4
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