From e153aa7990a09a8a12860fc1f79304b02a6bc03f Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 3 Oct 2016 09:11:49 -0700 Subject: [PATCH] xfs: set a default CoW extent size of 32 blocks If the admin doesn't set a CoW extent size or a regular extent size hint, default to creating CoW reservations 32 blocks long to reduce fragmentation. Signed-off-by: DarricK J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_inode.c | 10 ++++++---- fs/xfs/xfs_inode.h | 3 +++ 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 89e6441f963f..3332fb695cfd 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -80,7 +80,8 @@ xfs_get_extsz_hint( /* * Helper function to extract CoW extent size hint from inode. * Between the extent size hint and the CoW extent size hint, we - * return the greater of the two. + * return the greater of the two. If the value is zero (automatic), + * use the default size. */ xfs_extlen_t xfs_get_cowextsz_hint( @@ -93,9 +94,10 @@ xfs_get_cowextsz_hint( a = ip->i_d.di_cowextsize; b = xfs_get_extsz_hint(ip); - if (a > b) - return a; - return b; + a = max(a, b); + if (a == 0) + return XFS_DEFAULT_COWEXTSZ_HINT; + return a; } /* diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 6d63dc031127..f14c1de2549d 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -490,4 +490,7 @@ do { \ extern struct kmem_zone *xfs_inode_zone; +/* The default CoW extent size hint. */ +#define XFS_DEFAULT_COWEXTSZ_HINT 32 + #endif /* __XFS_INODE_H__ */