diff options
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 63 |
1 files changed, 52 insertions, 11 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index ac970b13b1f8..2dffd56a433c 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -352,6 +352,46 @@ xfs_quota_calc_throttle( } /* + * Determine if the previous extent's range of offsets is contiguous with + * @offset_fsb. If so, set @prev_contig to the number of blocks that are + * physically contiguous with that previous extent and return true. If there + * is no previous extent or there's a hole right before @offset_fsb, return + * false. + * + * Note that we don't care if the previous extents are written or not. + */ +static inline bool +xfs_iomap_prev_contiguous( + struct xfs_ifork *ifp, + struct xfs_iext_cursor *cur, + xfs_fileoff_t offset_fsb, + xfs_extlen_t *prev_contig) +{ + struct xfs_iext_cursor ncur = *cur; + struct xfs_bmbt_irec got, old; + + xfs_iext_prev(ifp, &ncur); + if (!xfs_iext_get_extent(ifp, &ncur, &old)) + return false; + if (old.br_startoff + old.br_blockcount < offset_fsb) + return false; + + *prev_contig = old.br_blockcount; + + xfs_iext_prev(ifp, &ncur); + while (xfs_iext_get_extent(ifp, &ncur, &got) && + got.br_blockcount + got.br_startoff == old.br_startoff && + got.br_blockcount + got.br_startblock == old.br_startblock && + *prev_contig <= MAXEXTLEN) { + *prev_contig += got.br_blockcount; + old = got; /* struct copy */ + xfs_iext_prev(ifp, &ncur); + } + + return true; +} + +/* * If we are doing a write at the end of the file and there are no allocations * past this one, then extend the allocation out to the file system's write * iosize. @@ -380,12 +420,12 @@ xfs_iomap_prealloc_size( struct xfs_mount *mp = ip->i_mount; struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); - struct xfs_bmbt_irec prev; int shift = 0; int64_t freesp; xfs_fsblock_t qblocks; int qshift = 0; xfs_fsblock_t alloc_blocks = 0; + xfs_extlen_t plen = 0; if (offset + count <= XFS_ISIZE(ip)) return 0; @@ -400,9 +440,9 @@ xfs_iomap_prealloc_size( */ if ((mp->m_flags & XFS_MOUNT_ALLOCSIZE) || XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) || - !xfs_iext_peek_prev_extent(ifp, icur, &prev) || - prev.br_startoff + prev.br_blockcount < offset_fsb) + !xfs_iomap_prev_contiguous(ifp, icur, offset_fsb, &plen)) { return mp->m_allocsize_blocks; + } /* * Determine the initial size of the preallocation. We are beyond the @@ -413,15 +453,16 @@ xfs_iomap_prealloc_size( * preallocation size. * * If the extent is a hole, then preallocation is essentially disabled. - * Otherwise we take the size of the preceding data extent as the basis - * for the preallocation size. If the size of the extent is greater than - * half the maximum extent length, then use the current offset as the - * basis. This ensures that for large files the preallocation size - * always extends to MAXEXTLEN rather than falling short due to things - * like stripe unit/width alignment of real extents. + * Otherwise we take the size of the contiguous preceding data extents + * as the basis for the preallocation size. If the size of the extent + * is greater than half the maximum extent length, then use the current + * offset as the basis. This ensures that for large files the + * preallocation size always extends to MAXEXTLEN rather than falling + * short due to things like stripe unit/width alignment of real + * extents. */ - if (prev.br_blockcount <= (MAXEXTLEN >> 1)) - alloc_blocks = prev.br_blockcount << 1; + if (plen <= (MAXEXTLEN >> 1)) + alloc_blocks = plen << 1; else alloc_blocks = XFS_B_TO_FSB(mp, offset); if (!alloc_blocks) |