From c2aecda79cd872679b9b11f9e59d797fb4c7d677 Mon Sep 17 00:00:00 2001 From: Joakim Tjernlund Date: Tue, 27 Mar 2007 13:32:09 +0200 Subject: [JFFS2] Speed up mount for directly-mapped NOR flash Remove excessive scanning of empty flash after a clean marker for users of the point/unpoint method. cfi_cmdset_0001 uses point/unpoint by default iff flash mapping is linear. The speedup is several orders of magnitude if FS is less than half full. Signed-off-by: Joakim Tjernlund Signed-off-by: David Woodhouse --- fs/jffs2/scan.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'fs/jffs2') diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c index a5103df5242e..7a46a436edfc 100644 --- a/fs/jffs2/scan.c +++ b/fs/jffs2/scan.c @@ -636,16 +636,17 @@ scan_more: if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { uint32_t inbuf_ofs; - uint32_t empty_start; + uint32_t empty_start, scan_end; empty_start = ofs; ofs += 4; + scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len); D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs)); more_empty: inbuf_ofs = ofs - buf_ofs; - while (inbuf_ofs < buf_len) { - if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) { + while (inbuf_ofs < scan_end) { + if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) { printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", empty_start, ofs); if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start))) @@ -666,7 +667,11 @@ scan_more: D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size))); return BLK_STATE_CLEANMARKER; } - + if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */ + scan_end = buf_len; + goto more_empty; + } + /* See how much more there is to read in this eraseblock... */ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); if (!buf_len) { @@ -676,6 +681,8 @@ scan_more: empty_start)); break; } + /* point never reaches here */ + scan_end = buf_len; D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs)); err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); if (err) -- cgit v1.2.1