mtd: part: Remove partition overlap checks

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=3a434f66e6dab645d74a59c95651cdbe16497a50
Commit:     3a434f66e6dab645d74a59c95651cdbe16497a50
Parent:     a62c24d75529118d10c45350c3b75715d52ff574
Author:     Dan Ehrenberg <dehrenberg at chromium.org>
AuthorDate: Thu Apr 2 15:15:12 2015 -0700
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Sun Apr 5 17:44:03 2015 -0700

    mtd: part: Remove partition overlap checks
    
    This patch makes MTD dynamic partitioning more flexible by removing
    overlap checks for dynamic partitions. I don't see any  particular
    reason why overlapping dynamic partitions should be prohibited while
    static partitions are allowed to overlap freely.
    
    The checks previously had an off-by-one error, where 'end' should be
    one less than what it is currently set at, and adding partitions out of
    increasing order will fail. Disabling the checks resolves this issue.
    
    Signed-off-by: Dan Ehrenberg <dehrenberg at chromium.org>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/mtdpart.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index be80340..cafdb88 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -582,8 +582,7 @@ int mtd_add_partition(struct mtd_info *master, const char *name,
 		      long long offset, long long length)
 {
 	struct mtd_partition part;
-	struct mtd_part *p, *new;
-	uint64_t start, end;
+	struct mtd_part *new;
 	int ret = 0;
 
 	/* the direct offset is expected */
@@ -607,21 +606,7 @@ int mtd_add_partition(struct mtd_info *master, const char *name,
 	if (IS_ERR(new))
 		return PTR_ERR(new);
 
-	start = offset;
-	end = offset + length;
-
 	mutex_lock(&mtd_partitions_mutex);
-	list_for_each_entry(p, &mtd_partitions, list)
-		if (p->master == master) {
-			if ((start >= p->offset) &&
-			    (start < (p->offset + p->mtd.size)))
-				goto err_inv;
-
-			if ((end >= p->offset) &&
-			    (end < (p->offset + p->mtd.size)))
-				goto err_inv;
-		}
-
 	list_add(&new->list, &mtd_partitions);
 	mutex_unlock(&mtd_partitions_mutex);
 
@@ -630,10 +615,6 @@ int mtd_add_partition(struct mtd_info *master, const char *name,
 	mtd_add_partition_attrs(new);
 
 	return ret;
-err_inv:
-	mutex_unlock(&mtd_partitions_mutex);
-	free_partition(new);
-	return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(mtd_add_partition);