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Commit 7eb3aa65 authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBI: fix eraseblock picking criteria 



The 'find_wl_entry()' function expects the maximum difference as the second
argument, not the maximum absolute value. So the "unknown" eraseblock picking
was incorrect, as Shmulik Ladkani spotted. This patch fixes the issue.

Reported-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
Cc: stable@kernel.org
parent add8287e

drivers/mtd/ubi/wl.c

+4 −6
Original line number Diff line number Diff line
@@ -390,7 +390,7 @@ static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int diff) 
 */

int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)

{

	int err, medium_ec;

	int err;

	struct ubi_wl_entry *e, *first, *last;



	ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
@@ -428,7 +428,7 @@ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype) 
		 * For unknown data we pick a physical eraseblock with medium

		 * erase counter. But we by no means can pick a physical

		 * eraseblock with erase counter greater or equivalent than the

		 * lowest erase counter plus %WL_FREE_MAX_DIFF.

		 * lowest erase counter plus %WL_FREE_MAX_DIFF/2.

		 */

		first = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry,

					u.rb);
@@ -437,10 +437,8 @@ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype) 
		if (last->ec - first->ec < WL_FREE_MAX_DIFF)

			e = rb_entry(ubi->free.rb_node,

					struct ubi_wl_entry, u.rb);

		else {

			medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;

			e = find_wl_entry(&ubi->free, medium_ec);

		}

		else

			e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF/2);

		break;

	case UBI_SHORTTERM:

		/*