From e7fdf0040660c2fa184ef176c02907a98bb6f5f5 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 12 Dec 2017 16:47:20 +0100 Subject: gfs2: Remove minor gfs2_journaled_truncate inefficiencies First, this function truncates the file in chunks. When the original file size isn't block aligned, each chunk that is truncated will remain be misaligned. This is inefficient. Second, this function doesn't recognize where holes are, so it loops through them. For each chunk of a hole, it creates a new transaction. At least avoid creating another transactions whe the current one is still empty. (An better fix would be to skip large holes, of course.) Signed-off-by: Andreas Gruenbacher Signed-off-by: Bob Peterson --- fs/gfs2/bmap.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'fs/gfs2') diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 963117f704bf..de0c3e3c1374 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1003,11 +1003,24 @@ static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize int error; while (oldsize != newsize) { + struct gfs2_trans *tr; + unsigned int offs; + chunk = oldsize - newsize; if (chunk > max_chunk) chunk = max_chunk; + + offs = oldsize & ~PAGE_MASK; + if (offs && chunk > PAGE_SIZE) + chunk = offs + ((chunk - offs) & PAGE_MASK); + truncate_pagecache(inode, oldsize - chunk); oldsize -= chunk; + + tr = current->journal_info; + if (!test_bit(TR_TOUCHED, &tr->tr_flags)) + continue; + gfs2_trans_end(sdp); error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES); if (error) -- cgit v1.2.3