4.18-stable review patch. If anyone has any objections, please let me know.
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From: Andreas Gruenbacher agruenba@redhat.com
commit e7445ceddfc220c1aede6d42758a5acb8844e9c3 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/gfs2/bmap.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1652,10 +1652,16 @@ static int punch_hole(struct gfs2_inode 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);