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authorMikulas Patocka2014-07-28 17:49:41 -0400
committerMike Snitzer2014-08-01 12:30:36 -0400
commit99eb1908e643609e83454c6fbcbb59f9055abf09 (patch)
treedd48bfd8f2521f35b75e839502727d76a91b6481 /drivers/md
parentb02465308f13f3266480275fd143747bfd441a2f (diff)
dm switch: factor out switch_region_table_read
Move code that reads the table to a switch_region_table_read. It will be needed for the next commit. No functional change. Tested-by: Jay Wang <jwang@nimblestorage.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-switch.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index 09a688b3d48c..c40e0954cec8 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -137,13 +137,23 @@ static void switch_get_position(struct switch_ctx *sctx, unsigned long region_nr
*bit *= sctx->region_table_entry_bits;
}
+static unsigned switch_region_table_read(struct switch_ctx *sctx, unsigned long region_nr)
+{
+ unsigned long region_index;
+ unsigned bit;
+
+ switch_get_position(sctx, region_nr, &region_index, &bit);
+
+ return (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
+ ((1 << sctx->region_table_entry_bits) - 1);
+}
+
/*
* Find which path to use at given offset.
*/
static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
{
- unsigned long region_index;
- unsigned bit, path_nr;
+ unsigned path_nr;
sector_t p;
p = offset;
@@ -152,9 +162,7 @@ static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
else
sector_div(p, sctx->region_size);
- switch_get_position(sctx, p, &region_index, &bit);
- path_nr = (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
- ((1 << sctx->region_table_entry_bits) - 1);
+ path_nr = switch_region_table_read(sctx, p);
/* This can only happen if the processor uses non-atomic stores. */
if (unlikely(path_nr >= sctx->nr_paths))