[PATCH 10/14] readahead: state based method: protect against tiny size

[Fengguang Wu]

Move the tiny I/O size protection code from limit_rala() to
state_based_readahead().

limit_rala() is also called by context based readahead, which has its own
minimal readahead size.

Signed-off-by: Fengguang Wu <wfg@xxxxxxxxxxxxxxxx>
---
 mm/readahead.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- linux-2.6.21-rc3-mm2.orig/mm/readahead.c
+++ linux-2.6.21-rc3-mm2/mm/readahead.c
@@ -1031,13 +1031,6 @@ static void limit_rala(unsigned long ra_
 	unsigned long stream_shift;
 
 	/*
-	 * Protect against too small I/O sizes,
-	 * by mapping [0, 4*min] to [min, 4*min].
-	 */
-	if (*ra_size < 4 * MIN_RA_PAGES)
-		*ra_size = MIN_RA_PAGES + *ra_size * 3 / 4;
-
-	/*
 	 * Apply basic upper limits.
 	 */
 	if (*ra_size > ra_max)
@@ -1145,6 +1138,13 @@ state_based_readahead(struct address_spa
 	if (!adjust_rala(&ra_size, &la_size))
 		goto cancel_lookahead;
 
+	/*
+	 * Protect against too small I/O sizes,
+	 * by mapping [0, 4*min] to [min, 4*min].
+	 */
+	if (ra_size < 4 * MIN_RA_PAGES)
+		ra_size = MIN_RA_PAGES + ra_size * 3 / 4;
+
 	growth_limit = req_size;
 	growth_limit += ra_max / 16;
 	growth_limit += 2 * ra_old;

--
-
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