diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2019-02-21 16:36:17 -0800 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-02-25 09:26:18 -0800 |
| commit | 4f29e10d689f5678b947df978bd0c96e4d70686f (patch) | |
| tree | 3a137535469142da030a21d337b7aa9d7f69a49b /fs/xfs | |
| parent | affe250a085d8230fa44fee1a0b7929a986e7580 (diff) | |
xfs: rework breaking of shared extents in xfs_file_iomap_begin
Rework the data flow in xfs_file_iomap_begin where we decide if we have
to break shared extents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index fa6621448d5e..63d323916bba 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -982,7 +982,7 @@ xfs_file_iomap_begin( * been done up front, so we don't need to do them here. */ if (xfs_is_cow_inode(ip)) { - struct xfs_bmbt_irec orig = imap; + struct xfs_bmbt_irec cmap; bool directio = (flags & IOMAP_DIRECT); /* if zeroing doesn't need COW allocation, then we are done. */ @@ -991,7 +991,8 @@ xfs_file_iomap_begin( goto out_found; /* may drop and re-acquire the ilock */ - error = xfs_reflink_allocate_cow(ip, &imap, &shared, &lockmode, + cmap = imap; + error = xfs_reflink_allocate_cow(ip, &cmap, &shared, &lockmode, directio); if (error) goto out_unlock; @@ -1002,10 +1003,11 @@ xfs_file_iomap_begin( * write code can perform read-modify-write operations; we * won't need the CoW fork mapping until writeback. For direct * I/O, which must be block aligned, we need to report the - * newly allocated address. + * newly allocated address. If the data fork has a hole, copy + * the COW fork mapping to avoid allocating to the data fork. */ - if (!directio && orig.br_startblock != HOLESTARTBLOCK) - imap = orig; + if (directio || imap.br_startblock == HOLESTARTBLOCK) + imap = cmap; end_fsb = imap.br_startoff + imap.br_blockcount; length = XFS_FSB_TO_B(mp, end_fsb) - offset; |