GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-03-18 04:54:52 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

xfs: also truncate holes covered by COW blocks

Browse source 
This only matters if we want to write data through the COW fork that is
not actually an overwrite of existing data.  Reasons for that are
speculative COW fork allocations using the cowextsize, or a mode where
we always write through the COW fork.  Currently both can't actually
happen, but I plan to enable them.

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>
This commit is contained in:
Christoph Hellwig 2019-02-18 09:38:47 -08:00 • committed by Darrick J. Wong
parent 78f0cc9d55
commit 12df89f28f
1 changed files with 16 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
fs/xfs/xfs_aops.c
View file

@ -447,27 +447,28 @@ retry:
wpc->fork = XFS_DATA_FORK;
/* landed in a hole or beyond EOF? */
if (imap.br_startoff > offset_fsb) {
/* landed in a hole or beyond EOF */
imap.br_blockcount = imap.br_startoff - offset_fsb;
imap.br_startoff = offset_fsb;
imap.br_startblock = HOLESTARTBLOCK;
imap.br_state = XFS_EXT_NORM;
} else {
}
/*
* Truncate to the next COW extent if there is one. This is the
* only opportunity to do this because we can skip COW fork
* lookups for the subsequent blocks in the mapping; however,
* the requirement to treat the COW range separately remains.
* Truncate to the next COW extent if there is one. This is the only
* opportunity to do this because we can skip COW fork lookups for the
* subsequent blocks in the mapping; however, the requirement to treat
* the COW range separately remains.
*/
if (cow_fsb != NULLFILEOFF &&
cow_fsb < imap.br_startoff + imap.br_blockcount)
imap.br_blockcount = cow_fsb - imap.br_startoff;
/* got a delalloc extent? */
if (isnullstartblock(imap.br_startblock))
if (imap.br_startblock != HOLESTARTBLOCK &&
isnullstartblock(imap.br_startblock))
goto allocate_blocks;
}
wpc->imap = imap;
trace_xfs_map_blocks_found(ip, offset, count, wpc->fork, &imap);