Commit 1739da40 authored Jun 09, 2010 by Tao Ma Committed by Joel Becker Jun 15, 2010

ocfs2: Limit default local alloc size within bitmap range.

In commit 6b82021b, we increase
our local alloc size and calculate how much megabytes we can
get according to group size and volume size.
But we also need to check the maximum bits a local alloc block
bitmap can have. With a bs=512, cs=32K, local volume with 160G,
it calculate 96MB while the maximum local alloc size is only
76M. So the bitmap will overflow and corrupt the system truncate
log file. See bug
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1262



Signed-off-by: Tao Ma <tao.ma@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

parent 40f165f4

fs/ocfs2/localalloc.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -118,6 +118,7 @@ unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
		{
		unsigned int la_mb;
		unsigned int gd_mb;
		unsigned int la_max_mb;
		unsigned int megs_per_slot;
		struct super_block *sb = osb->sb;

		@@ -182,6 +183,12 @@ unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
		if (megs_per_slot < la_mb)
		la_mb = megs_per_slot;

		/* We can't store more bits than we can in a block. */
		la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
		ocfs2_local_alloc_size(sb) * 8);
		if (la_mb > la_max_mb)
		la_mb = la_max_mb;

		return la_mb;
		}

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