diff options
author | Christoph Hellwig <hch@lst.de> | 2019-02-18 20:38:47 +0300 |
---|---|---|
committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-02-21 18:55:07 +0300 |
commit | db46e604adf8c923214a63b46e87ca2411d3d580 (patch) | |
tree | ec4797241a36cc5dc9d2b0d8fb466d8bc98f1bc1 | |
parent | 12df89f28fa92e54bfb2ae01f9ee059e74e1acc0 (diff) | |
download | linux-db46e604adf8c923214a63b46e87ca2411d3d580.tar.xz |
xfs: merge COW handling into xfs_file_iomap_begin_delay
Besides simplifying the code a bit this allows to actually implement
the behavior of using COW preallocation for non-COW data mentioned
in the current comments.
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/xfs_iomap.c | 133 | ||||
-rw-r--r-- | fs/xfs/xfs_reflink.c | 67 | ||||
-rw-r--r-- | fs/xfs/xfs_reflink.h | 2 | ||||
-rw-r--r-- | fs/xfs/xfs_trace.h | 3 |
4 files changed, 94 insertions, 111 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index be9d2a4b190a..08c4d1d8f90e 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -534,15 +534,16 @@ xfs_file_iomap_begin_delay( { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); xfs_fileoff_t maxbytes_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); xfs_fileoff_t end_fsb; - int error = 0, eof = 0; - struct xfs_bmbt_irec got; - struct xfs_iext_cursor icur; + struct xfs_bmbt_irec imap, cmap; + struct xfs_iext_cursor icur, ccur; xfs_fsblock_t prealloc_blocks = 0; + bool eof = false, cow_eof = false, shared; + int whichfork = XFS_DATA_FORK; + int error = 0; ASSERT(!XFS_IS_REALTIME_INODE(ip)); ASSERT(!xfs_get_extsz_hint(ip)); @@ -560,7 +561,7 @@ xfs_file_iomap_begin_delay( XFS_STATS_INC(mp, xs_blk_mapw); - if (!(ifp->if_flags & XFS_IFEXTENTS)) { + if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) { error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); if (error) goto out_unlock; @@ -568,51 +569,92 @@ xfs_file_iomap_begin_delay( end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); - eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got); + /* + * Search the data fork fork first to look up our source mapping. We + * always need the data fork map, as we have to return it to the + * iomap code so that the higher level write code can read data in to + * perform read-modify-write cycles for unaligned writes. + */ + eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap); if (eof) - got.br_startoff = end_fsb; /* fake hole until the end */ + imap.br_startoff = end_fsb; /* fake hole until the end */ + + /* We never need to allocate blocks for zeroing a hole. */ + if ((flags & IOMAP_ZERO) && imap.br_startoff > offset_fsb) { + xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff); + goto out_unlock; + } + + /* + * Search the COW fork extent list even if we did not find a data fork + * extent. This serves two purposes: first this implements the + * speculative preallocation using cowextsize, so that we also unshare + * block adjacent to shared blocks instead of just the shared blocks + * themselves. Second the lookup in the extent list is generally faster + * than going out to the shared extent tree. + */ + if (xfs_is_reflink_inode(ip)) { + cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, + &ccur, &cmap); + if (!cow_eof && cmap.br_startoff <= offset_fsb) { + trace_xfs_reflink_cow_found(ip, &cmap); + whichfork = XFS_COW_FORK; + goto done; + } + } - if (got.br_startoff <= offset_fsb) { + if (imap.br_startoff <= offset_fsb) { /* * For reflink files we may need a delalloc reservation when * overwriting shared extents. This includes zeroing of * existing extents that contain data. */ - if (xfs_is_reflink_inode(ip) && - ((flags & IOMAP_WRITE) || - got.br_state != XFS_EXT_UNWRITTEN)) { - xfs_trim_extent(&got, offset_fsb, end_fsb - offset_fsb); - error = xfs_reflink_reserve_cow(ip, &got); - if (error) - goto out_unlock; + if (!xfs_is_reflink_inode(ip) || + ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) { + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK, + &imap); + goto done; } - trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK, &got); - goto done; - } + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); - if (flags & IOMAP_ZERO) { - xfs_hole_to_iomap(ip, iomap, offset_fsb, got.br_startoff); - goto out_unlock; + /* Trim the mapping to the nearest shared extent boundary. */ + error = xfs_reflink_trim_around_shared(ip, &imap, &shared); + if (error) + goto out_unlock; + + /* Not shared? Just report the (potentially capped) extent. */ + if (!shared) { + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK, + &imap); + goto done; + } + + /* + * Fork all the shared blocks from our write offset until the + * end of the extent. + */ + whichfork = XFS_COW_FORK; + end_fsb = imap.br_startoff + imap.br_blockcount; + } else { + /* + * We cap the maximum length we map here to MAX_WRITEBACK_PAGES + * pages to keep the chunks of work done where somewhat + * symmetric with the work writeback does. This is a completely + * arbitrary number pulled out of thin air. + * + * Note that the values needs to be less than 32-bits wide until + * the lower level functions are updated. + */ + count = min_t(loff_t, count, 1024 * PAGE_SIZE); + end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); } error = xfs_qm_dqattach_locked(ip, false); if (error) goto out_unlock; - /* - * We cap the maximum length we map here to MAX_WRITEBACK_PAGES pages - * to keep the chunks of work done where somewhat symmetric with the - * work writeback does. This is a completely arbitrary number pulled - * out of thin air as a best guess for initial testing. - * - * Note that the values needs to be less than 32-bits wide until - * the lower level functions are updated. - */ - count = min_t(loff_t, count, 1024 * PAGE_SIZE); - end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); - - if (eof) { + if (eof && whichfork == XFS_DATA_FORK) { prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, &icur); if (prealloc_blocks) { @@ -635,9 +677,11 @@ xfs_file_iomap_begin_delay( } retry: - error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb, - end_fsb - offset_fsb, prealloc_blocks, &got, &icur, - eof); + error = xfs_bmapi_reserve_delalloc(ip, whichfork, offset_fsb, + end_fsb - offset_fsb, prealloc_blocks, + whichfork == XFS_DATA_FORK ? &imap : &cmap, + whichfork == XFS_DATA_FORK ? &icur : &ccur, + whichfork == XFS_DATA_FORK ? eof : cow_eof); switch (error) { case 0: break; @@ -659,9 +703,20 @@ retry: * them out if the write happens to fail. */ iomap->flags |= IOMAP_F_NEW; - trace_xfs_iomap_alloc(ip, offset, count, XFS_DATA_FORK, &got); + trace_xfs_iomap_alloc(ip, offset, count, whichfork, + whichfork == XFS_DATA_FORK ? &imap : &cmap); done: - error = xfs_bmbt_to_iomap(ip, iomap, &got, false); + if (whichfork == XFS_COW_FORK) { + if (imap.br_startoff > offset_fsb) { + xfs_trim_extent(&cmap, offset_fsb, + imap.br_startoff - offset_fsb); + error = xfs_bmbt_to_iomap(ip, iomap, &cmap, false); + goto out_unlock; + } + /* ensure we only report blocks we have a reservation for */ + xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount); + } + error = xfs_bmbt_to_iomap(ip, iomap, &imap, false); out_unlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 8a5353daf9ab..9ef1f79cb3ae 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -234,73 +234,6 @@ xfs_reflink_trim_around_shared( } } -/* - * Trim the passed in imap to the next shared/unshared extent boundary, and - * if imap->br_startoff points to a shared extent reserve space for it in the - * COW fork. - * - * Note that imap will always contain the block numbers for the existing blocks - * in the data fork, as the upper layers need them for read-modify-write - * operations. - */ -int -xfs_reflink_reserve_cow( - struct xfs_inode *ip, - struct xfs_bmbt_irec *imap) -{ - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); - struct xfs_bmbt_irec got; - int error = 0; - bool eof = false; - struct xfs_iext_cursor icur; - bool shared; - - /* - * Search the COW fork extent list first. This serves two purposes: - * first this implement the speculative preallocation using cowextisze, - * so that we also unshared block adjacent to shared blocks instead - * of just the shared blocks themselves. Second the lookup in the - * extent list is generally faster than going out to the shared extent - * tree. - */ - - if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &icur, &got)) - eof = true; - if (!eof && got.br_startoff <= imap->br_startoff) { - trace_xfs_reflink_cow_found(ip, imap); - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); - return 0; - } - - /* Trim the mapping to the nearest shared extent boundary. */ - error = xfs_reflink_trim_around_shared(ip, imap, &shared); - if (error) - return error; - - /* Not shared? Just report the (potentially capped) extent. */ - if (!shared) - return 0; - - /* - * Fork all the shared blocks from our write offset until the end of - * the extent. - */ - error = xfs_qm_dqattach_locked(ip, false); - if (error) - return error; - - error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, - imap->br_blockcount, 0, &got, &icur, eof); - if (error == -ENOSPC || error == -EDQUOT) - trace_xfs_reflink_cow_enospc(ip, imap); - if (error) - return error; - - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); - trace_xfs_reflink_cow_alloc(ip, &got); - return 0; -} - /* Convert part of an unwritten CoW extent to a real one. */ STATIC int xfs_reflink_convert_cow_extent( diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h index 70d68a1a9b49..4a9e3cd4768a 100644 --- a/fs/xfs/xfs_reflink.h +++ b/fs/xfs/xfs_reflink.h @@ -12,8 +12,6 @@ extern int xfs_reflink_find_shared(struct xfs_mount *mp, struct xfs_trans *tp, extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip, struct xfs_bmbt_irec *irec, bool *shared); -extern int xfs_reflink_reserve_cow(struct xfs_inode *ip, - struct xfs_bmbt_irec *imap); extern int xfs_reflink_allocate_cow(struct xfs_inode *ip, struct xfs_bmbt_irec *imap, bool *shared, uint *lockmode, unsigned iomap_flags); diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index f1e18ae8a209..47fb07d86efd 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -3196,13 +3196,10 @@ DEFINE_INODE_ERROR_EVENT(xfs_reflink_unshare_error); /* copy on write */ DEFINE_INODE_IREC_EVENT(xfs_reflink_trim_around_shared); -DEFINE_INODE_IREC_EVENT(xfs_reflink_cow_alloc); DEFINE_INODE_IREC_EVENT(xfs_reflink_cow_found); DEFINE_INODE_IREC_EVENT(xfs_reflink_cow_enospc); DEFINE_INODE_IREC_EVENT(xfs_reflink_convert_cow); -DEFINE_RW_EVENT(xfs_reflink_reserve_cow); - DEFINE_SIMPLE_IO_EVENT(xfs_reflink_bounce_dio_write); DEFINE_SIMPLE_IO_EVENT(xfs_reflink_cancel_cow_range); |