From 78f0cc9d55cbe75faccc0135371c45912a34e6ed Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 18 Feb 2019 09:38:46 -0800 Subject: xfs: don't use delalloc extents for COW on files with extsize hints While using delalloc for extsize hints is generally a good idea, the current code that does so only for COW doesn't help us much and creates a lot of special cases. Switch it to use real allocations like we do for direct I/O. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_iomap.c | 29 ++++++++++++++++++----------- fs/xfs/xfs_reflink.c | 10 +++++++++- fs/xfs/xfs_reflink.h | 3 ++- 3 files changed, 29 insertions(+), 13 deletions(-) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index df6eda336f17..be9d2a4b190a 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -918,22 +918,29 @@ xfs_file_iomap_begin( * been done up front, so we don't need to do them here. */ if (xfs_is_reflink_inode(ip)) { + struct xfs_bmbt_irec orig = imap; + /* if zeroing doesn't need COW allocation, then we are done. */ if ((flags & IOMAP_ZERO) && !needs_cow_for_zeroing(&imap, nimaps)) goto out_found; - if (flags & IOMAP_DIRECT) { - /* may drop and re-acquire the ilock */ - error = xfs_reflink_allocate_cow(ip, &imap, &shared, - &lockmode); - if (error) - goto out_unlock; - } else { - error = xfs_reflink_reserve_cow(ip, &imap); - if (error) - goto out_unlock; - } + /* may drop and re-acquire the ilock */ + error = xfs_reflink_allocate_cow(ip, &imap, &shared, &lockmode, + flags); + if (error) + goto out_unlock; + + /* + * For buffered writes we need to report the address of the + * previous block (if there was any) so that the higher level + * write code can perform read-modify-write operations. For + * direct I/O code, which must be block aligned we need to + * report the newly allocated address. + */ + if (!(flags & IOMAP_DIRECT) && + orig.br_startblock != HOLESTARTBLOCK) + imap = orig; end_fsb = imap.br_startoff + imap.br_blockcount; length = XFS_FSB_TO_B(mp, end_fsb) - offset; diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 2babc2cbe103..8a5353daf9ab 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -397,7 +397,8 @@ xfs_reflink_allocate_cow( struct xfs_inode *ip, struct xfs_bmbt_irec *imap, bool *shared, - uint *lockmode) + uint *lockmode, + unsigned iomap_flags) { struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb = imap->br_startoff; @@ -471,6 +472,13 @@ xfs_reflink_allocate_cow( if (nimaps == 0) return -ENOSPC; convert: + /* + * COW fork extents are supposed to remain unwritten until we're ready + * to initiate a disk write. For direct I/O we are going to write the + * data and need the conversion, but for buffered writes we're done. + */ + if (!(iomap_flags & IOMAP_DIRECT)) + return 0; return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb); out_unreserve: diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h index 6d73daef1f13..70d68a1a9b49 100644 --- a/fs/xfs/xfs_reflink.h +++ b/fs/xfs/xfs_reflink.h @@ -15,7 +15,8 @@ extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip, 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); + struct xfs_bmbt_irec *imap, bool *shared, uint *lockmode, + unsigned iomap_flags); extern int xfs_reflink_convert_cow(struct xfs_inode *ip, xfs_off_t offset, xfs_off_t count); -- cgit