Merge branch 'percpu-for-linus' into percpu-for-next

Conflicts:
	arch/sparc/kernel/smp_64.c
	arch/x86/kernel/cpu/perf_counter.c
	arch/x86/kernel/setup_percpu.c
	drivers/cpufreq/cpufreq_ondemand.c
	mm/percpu.c

Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index c3d653ba5ca0..b847745394b4 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -757,6 +757,8 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 	si->is_empty = 0;
 
 	if (!ec_corr) {
+		int image_seq;
+
 		/* Make sure UBI version is OK */
 		if (ech->version != UBI_VERSION) {
 			ubi_err("this UBI version is %d, image version is %d",
@@ -778,6 +780,29 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 			ubi_dbg_dump_ec_hdr(ech);
 			return -EINVAL;
 		}
+
+		/*
+		 * Make sure that all PEBs have the same image sequence number.
+		 * This allows us to detect situations when users flash UBI
+		 * images incorrectly, so that the flash has the new UBI image
+		 * and leftovers from the old one. This feature was added
+		 * relatively recently, and the sequence number was always
+		 * zero, because old UBI implementations always set it to zero.
+		 * For this reasons, we do not panic if some PEBs have zero
+		 * sequence number, while other PEBs have non-zero sequence
+		 * number.
+		 */
+		image_seq = be32_to_cpu(ech->image_seq);
+		if (!si->image_seq_set) {
+			ubi->image_seq = image_seq;
+			si->image_seq_set = 1;
+		} else if (ubi->image_seq && ubi->image_seq != image_seq) {
+			ubi_err("bad image sequence number %d in PEB %d, "
+				"expected %d", image_seq, pnum, ubi->image_seq);
+			ubi_dbg_dump_ec_hdr(ech);
+			return -EINVAL;
+		}
+
 	}
 
 	/* OK, we've done with the EC header, let's look at the VID header */