From 8f78fc5eb798426891f99390a61f752aaef9fc39 Mon Sep 17 00:00:00 2001 From: Kai Makisara Date: Thu, 18 Dec 2008 14:49:51 +0900 Subject: [PATCH] [SCSI] st: retry enlarge_buffer allocation Make enlarge_buffer() retry allocation if the previously chosen page order was too small. Really limit the page order to 6. Return error if the maximum order is not large enough for the request. Signed-off-by: Kai Makisara Signed-off-by: James Bottomley --- drivers/scsi/st.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index ddf2630b3479..c6f19ee8f2cb 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -3695,6 +3695,8 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg) /* Try to allocate enough space in the tape buffer */ +#define ST_MAX_ORDER 6 + static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma) { int segs, nbr, max_segs, b_size, order, got; @@ -3723,9 +3725,16 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm b_size = PAGE_SIZE << order; } else { for (b_size = PAGE_SIZE, order = 0; - order <= 6 && b_size < new_size; order++, b_size *= 2) + order < ST_MAX_ORDER && b_size < new_size; + order++, b_size *= 2) ; /* empty */ } + if (max_segs * (PAGE_SIZE << order) < new_size) { + if (order == ST_MAX_ORDER) + return 0; + normalize_buffer(STbuffer); + return enlarge_buffer(STbuffer, new_size, need_dma); + } for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size; segs < max_segs && got < new_size;) {