xfs: allocate direct I/O COW blocks in iomap_begin
Instead of preallocating all the required COW blocks in the high-level
write code do it inside the iomap code, like we do for all other I/O.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 9bba084..1f61877 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -382,74 +382,75 @@
}
/* Allocate all CoW reservations covering a range of blocks in a file. */
-static int
-__xfs_reflink_allocate_cow(
+int
+xfs_reflink_allocate_cow(
struct xfs_inode *ip,
- xfs_fileoff_t *offset_fsb,
- xfs_fileoff_t end_fsb)
+ struct xfs_bmbt_irec *imap,
+ bool *shared,
+ uint *lockmode)
{
struct xfs_mount *mp = ip->i_mount;
- struct xfs_bmbt_irec imap, got;
+ xfs_fileoff_t offset_fsb = imap->br_startoff;
+ xfs_filblks_t count_fsb = imap->br_blockcount;
+ struct xfs_bmbt_irec got;
struct xfs_defer_ops dfops;
- struct xfs_trans *tp;
+ struct xfs_trans *tp = NULL;
xfs_fsblock_t first_block;
- int nimaps, error, lockmode;
- bool shared, trimmed;
+ int nimaps, error = 0;
+ bool trimmed;
xfs_filblks_t resaligned;
- xfs_extlen_t resblks;
+ xfs_extlen_t resblks = 0;
xfs_extnum_t idx;
- resaligned = xfs_aligned_fsb_count(*offset_fsb, end_fsb - *offset_fsb,
- xfs_get_cowextsz_hint(ip));
- resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
-
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
- if (error)
- return error;
-
- lockmode = XFS_ILOCK_EXCL;
- xfs_ilock(ip, lockmode);
+retry:
+ ASSERT(xfs_is_reflink_inode(ip));
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
/*
* 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 (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &idx, &got) &&
+ got.br_startoff <= offset_fsb) {
+ *shared = true;
+
/* 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;
+ xfs_trim_extent(&got, offset_fsb, count_fsb);
+ *imap = got;
+ goto convert;
}
+
+ xfs_trim_extent(imap, got.br_startoff, got.br_blockcount);
} else {
- nimaps = 1;
- error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb,
- &imap, &nimaps, 0);
+ error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed);
+ if (error || !*shared)
+ goto out;
+ }
+
+ if (!tp) {
+ resaligned = xfs_aligned_fsb_count(imap->br_startoff,
+ imap->br_blockcount, xfs_get_cowextsz_hint(ip));
+ resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
+
+ xfs_iunlock(ip, *lockmode);
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+ *lockmode = XFS_ILOCK_EXCL;
+ xfs_ilock(ip, *lockmode);
+
if (error)
- goto out_trans_cancel;
- ASSERT(nimaps == 1);
+ return error;
- /* Trim the mapping to the nearest shared extent boundary. */
- error = xfs_reflink_trim_around_shared(ip, &imap, &shared,
- &trimmed);
+ error = xfs_qm_dqattach_locked(ip, 0);
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;
+ goto out;
+ goto retry;
}
error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
XFS_QMOPT_RES_REGBLKS);
if (error)
- goto out_trans_cancel;
+ goto out;
xfs_trans_ijoin(tp, ip, 0);
@@ -457,9 +458,9 @@
nimaps = 1;
/* Allocate the entire reservation as unwritten blocks. */
- error = xfs_bmapi_write(tp, ip, *offset_fsb, end_fsb - *offset_fsb,
+ error = xfs_bmapi_write(tp, ip, imap->br_startoff, imap->br_blockcount,
XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, &first_block,
- resblks, &imap, &nimaps, &dfops);
+ resblks, imap, &nimaps, &dfops);
if (error)
goto out_bmap_cancel;
@@ -470,57 +471,18 @@
error = xfs_trans_commit(tp);
if (error)
- goto out_unlock;
-
- *offset_fsb = imap.br_startoff + imap.br_blockcount;
-
-out_unlock:
- xfs_iunlock(ip, lockmode);
- return error;
-
+ return error;
+convert:
+ return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb,
+ &dfops);
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;
-}
-
-/* Allocate all CoW reservations covering a part of a file. */
-int
-xfs_reflink_allocate_cow_range(
- struct xfs_inode *ip,
- xfs_off_t offset,
- xfs_off_t count)
-{
- struct xfs_mount *mp = ip->i_mount;
- xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
- xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count);
- int error;
-
- ASSERT(xfs_is_reflink_inode(ip));
-
- trace_xfs_reflink_allocate_cow_range(ip, offset, count);
-
- /*
- * Make sure that the dquots are there.
- */
- error = xfs_qm_dqattach(ip, 0);
- if (error)
- return error;
-
- while (offset_fsb < end_fsb) {
- error = __xfs_reflink_allocate_cow(ip, &offset_fsb, end_fsb);
- if (error) {
- trace_xfs_reflink_allocate_cow_range_error(ip, error,
- _RET_IP_);
- return error;
- }
- }
-
- /* Convert the CoW extents to regular. */
- return xfs_reflink_convert_cow(ip, offset, count);
+out:
+ if (tp)
+ xfs_trans_cancel(tp);
+ return error;
}
/*