The previous attempt to fix for metadata read-ahead during truncate was incorrect: for files with a height > 2 (1006989312 bytes with a block size of 4096 bytes), read-ahead requests were not being issued for some of the indirect blocks discovered while walking the metadata tree, leading to significant slow-downs when deleting large files. Fix that.

In addition, only issue read-ahead requests in the first pass through the meta-data tree, while deallocating data blocks.

Fixes: c3ce5aa9b0 ("gfs2: Fix metadata read-ahead during truncate") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Andreas Gruenbacher agruenba@redhat.com --- fs/gfs2/bmap.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 5f3ea07ef5e2..38d88fcb6988 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1908,10 +1908,16 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length) if (ret < 0) goto out;

- /* issue read-ahead on metadata */ - if (mp.mp_aheight > 1) { - for (; ret > 1; ret--) { - metapointer_range(&mp, mp.mp_aheight - ret, + /* On the first pass, issue read-ahead on metadata. */ + if (mp.mp_aheight > 1 && strip_h == ip->i_height - 1) { + unsigned int height = mp.mp_aheight - 1; + + /* No read-ahead for data blocks. */ + if (mp.mp_aheight - 1 == strip_h) + height--; + + for (; height >= mp.mp_aheight - ret; height--) { + metapointer_range(&mp, height, start_list, start_aligned, end_list, end_aligned, &start, &end);