From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 9196A7DF0 for ; Thu, 25 Aug 2016 18:36:26 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id 648A88F8033 for ; Thu, 25 Aug 2016 16:36:26 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69]) by cuda.sgi.com with ESMTP id EtWm0t9z9JBLTqgC (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 25 Aug 2016 16:36:24 -0700 (PDT) Subject: [PATCH 40/71] xfs: report shared extents through the iomap interface From: "Darrick J. Wong" Date: Thu, 25 Aug 2016 16:36:17 -0700 Message-ID: <147216817787.867.4276938642586853650.stgit@birch.djwong.org> In-Reply-To: <147216791538.867.12413509832420924168.stgit@birch.djwong.org> References: <147216791538.867.12413509832420924168.stgit@birch.djwong.org> MIME-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: david@fromorbit.com, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, xfs@oss.sgi.com Report shared extents through the iomap interface so that FIEMAP reports shared blocks accurately. Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_iomap.c | 19 ++++++++++++--- fs/xfs/xfs_iomap.h | 2 +- fs/xfs/xfs_pnfs.c | 2 +- fs/xfs/xfs_reflink.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_reflink.h | 3 ++ 5 files changed, 82 insertions(+), 6 deletions(-) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 6065bde..130010a 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -987,10 +987,13 @@ void xfs_bmbt_to_iomap( struct xfs_inode *ip, struct iomap *iomap, - struct xfs_bmbt_irec *imap) + struct xfs_bmbt_irec *imap, + bool is_shared) { struct xfs_mount *mp = ip->i_mount; + if (is_shared) + iomap->flags |= IOMAP_F_SHARED; if (imap->br_startblock == HOLESTARTBLOCK) { iomap->blkno = IOMAP_NULL_BLOCK; iomap->type = IOMAP_HOLE; @@ -1028,6 +1031,7 @@ xfs_file_iomap_begin( struct xfs_mount *mp = ip->i_mount; struct xfs_bmbt_irec imap; xfs_fileoff_t offset_fsb, end_fsb; + bool shared, trimmed; int nimaps = 1, error = 0; if (XFS_FORCED_SHUTDOWN(mp)) @@ -1053,7 +1057,14 @@ xfs_file_iomap_begin( } error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, - &nimaps, XFS_BMAPI_ENTIRE); + &nimaps, 0); + if (error) { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; + } + + /* Trim the mapping to the nearest shared extent boundary. */ + error = xfs_reflink_trim_around_shared(ip, &imap, &shared, &trimmed); if (error) { xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; @@ -1095,7 +1106,7 @@ xfs_file_iomap_begin( trace_xfs_iomap_found(ip, offset, length, 0, &imap); } - xfs_bmbt_to_iomap(ip, iomap, &imap); + xfs_bmbt_to_iomap(ip, iomap, &imap, shared); return 0; } @@ -1193,7 +1204,7 @@ out_unlock: if (!error) { ASSERT(nimaps); - xfs_bmbt_to_iomap(ip, iomap, &imap); + xfs_bmbt_to_iomap(ip, iomap, &imap, false); } return error; diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h index 52f9c99..c04bf99 100644 --- a/fs/xfs/xfs_iomap.h +++ b/fs/xfs/xfs_iomap.h @@ -34,7 +34,7 @@ int xfs_iomap_cow_delay(struct xfs_inode *, xfs_off_t, size_t, struct xfs_bmbt_irec *); void xfs_bmbt_to_iomap(struct xfs_inode *, struct iomap *, - struct xfs_bmbt_irec *); + struct xfs_bmbt_irec *, bool); extern struct iomap_ops xfs_iomap_ops; extern struct iomap_ops xfs_xattr_iomap_ops; diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c index 93a7aaf..5519e4b 100644 --- a/fs/xfs/xfs_pnfs.c +++ b/fs/xfs/xfs_pnfs.c @@ -188,7 +188,7 @@ xfs_fs_map_blocks( } xfs_iunlock(ip, XFS_IOLOCK_EXCL); - xfs_bmbt_to_iomap(ip, iomap, &imap); + xfs_bmbt_to_iomap(ip, iomap, &imap, false); *device_generation = mp->m_generation; return error; out_unlock: diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 82d66a4..885ec61 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -179,6 +179,68 @@ xfs_reflink_find_shared( return error; } +/* + * Trim the mapping to the next block where there's a change in the + * shared/unshared status. More specifically, this means that we + * find the lowest-numbered extent of shared blocks that coincides with + * the given block mapping. If the shared extent overlaps the start of + * the mapping, trim the mapping to the end of the shared extent. If + * the shared region intersects the mapping, trim the mapping to the + * start of the shared extent. If there are no shared regions that + * overlap, just return the original extent. + */ +int +xfs_reflink_trim_around_shared( + struct xfs_inode *ip, + struct xfs_bmbt_irec *irec, + bool *shared, + bool *trimmed) +{ + xfs_agnumber_t agno; + xfs_agblock_t agbno; + xfs_extlen_t aglen; + xfs_agblock_t fbno; + xfs_extlen_t flen; + int error = 0; + + /* Holes, unwritten, and delalloc extents cannot be shared */ + if (!xfs_is_reflink_inode(ip) || + ISUNWRITTEN(irec) || + irec->br_startblock == HOLESTARTBLOCK || + irec->br_startblock == DELAYSTARTBLOCK) { + *shared = false; + return 0; + } + + trace_xfs_reflink_trim_around_shared(ip, irec); + + agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock); + agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock); + aglen = irec->br_blockcount; + + error = xfs_reflink_find_shared(ip->i_mount, agno, agbno, + aglen, &fbno, &flen, true); + if (error) + return error; + + *shared = *trimmed = false; + if (flen == 0) { + /* No shared blocks at all. */ + return 0; + } else if (fbno == agbno) { + /* The start of this extent is shared. */ + irec->br_blockcount = flen; + *shared = true; + *trimmed = true; + return 0; + } else { + /* There's a shared extent midway through this extent. */ + irec->br_blockcount = fbno - agbno; + *trimmed = true; + return 0; + } +} + /* Find the shared ranges under an irec, and set up delalloc extents. */ static int xfs_reflink_reserve_cow_extent( diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h index 0ffabfb..e0bad68 100644 --- a/fs/xfs/xfs_reflink.h +++ b/fs/xfs/xfs_reflink.h @@ -23,6 +23,9 @@ extern int xfs_reflink_find_shared(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno, xfs_extlen_t *flen, bool find_maximal); +extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip, + struct xfs_bmbt_irec *irec, bool *shared, bool *trimmed); + extern int xfs_reflink_reserve_cow_range(struct xfs_inode *ip, xfs_fileoff_t offset_fsb, xfs_fileoff_t end_fsb); extern bool xfs_reflink_is_cow_pending(struct xfs_inode *ip, xfs_off_t offset); _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs