From 23e5671a79be00b2f1c895aa93ff40fb75a4647e Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 16 Aug 2016 13:25:22 +0200 Subject: [PATCH] gfs2: Fix extended attribute readahead optimization Commit 39b0555f didn't check for a failing bio_add_page in gfs2_submit_bhs. This could cause I/O requests to get lost, and the affected buffer heads to stay locked forever. Fix that by submitting the current bio and allocating another one when bio_add_page fails. (It is guaranteed that we can at least add one page to a bio.) Signed-off-by: Andreas Gruenbacher Signed-off-by: Bob Peterson --- fs/gfs2/meta_io.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c index 950b8be68e41..373639a59782 100644 --- a/fs/gfs2/meta_io.c +++ b/fs/gfs2/meta_io.c @@ -216,23 +216,26 @@ static void gfs2_meta_read_endio(struct bio *bio) static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[], int num) { - struct buffer_head *bh = bhs[0]; - struct bio *bio; - int i; - - if (!num) - return; - - bio = bio_alloc(GFP_NOIO, num); - bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); - bio->bi_bdev = bh->b_bdev; - for (i = 0; i < num; i++) { - bh = bhs[i]; - bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh)); + while (num > 0) { + struct buffer_head *bh = *bhs; + struct bio *bio; + + bio = bio_alloc(GFP_NOIO, num); + bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); + bio->bi_bdev = bh->b_bdev; + while (num > 0) { + bh = *bhs; + if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) { + BUG_ON(bio->bi_iter.bi_size == 0); + break; + } + bhs++; + num--; + } + bio->bi_end_io = gfs2_meta_read_endio; + bio_set_op_attrs(bio, op, op_flags); + submit_bio(bio); } - bio->bi_end_io = gfs2_meta_read_endio; - bio_set_op_attrs(bio, op, op_flags); - submit_bio(bio); } /** -- 2.20.1