ore: fix BUG_ON, too few sgs when reading (361aba56) · Commits · 戴 / test

When reading RAID5 files, in rare cases, we calculated too few sg segments. There should be two extra for the beginning and end partial units. Also "too few sg segments" should not be a BUG_ON there is all the mechanics in place to handle it, as a short read. So just return -ENOMEM and the rest of the code will gracefully split the IO. [Bug in 3.2.0 Kernel] CC: Stable Tree <stable@kernel.org> Signed-off-by:

Boaz Harrosh <bharrosh@panasas.com>

fs/exofs/ore.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -266,7 +266,7 @@ int ore_get_rw_state(struct ore_layout layout, struct ore_components oc,

		/* first/last seg is split */
		num_raid_units += layout->group_width;
		sgs_per_dev = div_u64(num_raid_units, data_devs);
		sgs_per_dev = div_u64(num_raid_units, data_devs) + 2;
		} else {
		/* For Writes add parity pages array. */
		max_par_pages = num_raid_units * pages_in_unit *

fs/exofs/ore_raid.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -551,7 +551,11 @@ int _ore_add_parity_unit(struct ore_io_state *ios,
		unsigned cur_len)
		{
		if (ios->reading) {
		BUG_ON(per_dev->cur_sg >= ios->sgs_per_dev);
		if (per_dev->cur_sg >= ios->sgs_per_dev) {
		ORE_DBGMSG("cur_sg(%d) >= sgs_per_dev(%d)\n" ,
		per_dev->cur_sg, ios->sgs_per_dev);
		return -ENOMEM;
		}
		_ore_add_sg_seg(per_dev, cur_len, true);
		} else {
		struct __stripe_pages_2d *sp2d = ios->sp2d;

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