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author | 2017-02-06 10:50:49 -0800 | |
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committer | 2017-02-06 17:47:47 -0800 | |
commit | a14234c72bf41ac96bc8c98e96e2c84b6d4bd4f2 (patch) | |
tree | 711d321fd0656ef512522b0293a12b836d6afecd | |
parent | xfs: return the converted extent in __xfs_reflink_convert_cow (diff) | |
download | linux-a14234c72bf41ac96bc8c98e96e2c84b6d4bd4f2.tar.gz linux-a14234c72bf41ac96bc8c98e96e2c84b6d4bd4f2.tar.bz2 linux-a14234c72bf41ac96bc8c98e96e2c84b6d4bd4f2.zip |
xfs: go straight to real allocations for direct I/O COW writes
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@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 3 | ||||
-rw-r--r-- | fs/xfs/xfs_reflink.c | 94 |
2 files changed, 68 insertions, 29 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index dcffbb09444e..1cee514de19e 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -2895,13 +2895,14 @@ 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. diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 219bc96bfc71..9bba084c1436 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -389,62 +389,100 @@ __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_filblks_t resaligned; + xfs_extlen_t resblks; + xfs_extnum_t idx; - xfs_defer_init(&dfops, &first_block); + 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, 0, 0, - XFS_TRANS_RESERVE, &tp); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); if (error) return error; - xfs_ilock(ip, XFS_ILOCK_EXCL); + lockmode = XFS_ILOCK_EXCL; + xfs_ilock(ip, lockmode); - /* Read extent from the source file. */ - nimaps = 1; - error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb, - &imap, &nimaps, 0); - if (error) - goto out_unlock; - ASSERT(nimaps == 1); + /* + * 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; + } - /* Make sure there's a CoW reservation for it. */ - error = xfs_reflink_reserve_cow(ip, &imap, &shared); + *offset_fsb = imap.br_startoff; + end_fsb = imap.br_startoff + imap.br_blockcount; + } + + error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, + XFS_QMOPT_RES_REGBLKS); if (error) goto out_trans_cancel; - if (!shared) { - *offset_fsb = imap.br_startoff + imap.br_blockcount; - goto out_trans_cancel; - } + xfs_trans_ijoin(tp, ip, 0); + + xfs_defer_init(&dfops, &first_block); + nimaps = 1; /* Allocate the entire reservation as unwritten blocks. */ - xfs_trans_ijoin(tp, ip, 0); - error = xfs_bmapi_write(tp, ip, imap.br_startoff, imap.br_blockcount, + error = xfs_bmapi_write(tp, ip, *offset_fsb, end_fsb - *offset_fsb, XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, &first_block, - XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), - &imap, &nimaps, &dfops); + resblks, &imap, &nimaps, &dfops); if (error) - goto out_trans_cancel; + goto out_bmap_cancel; /* Finish up. */ 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; } |