From a3a447848a153d0dae63d02ceb94b02fb43ec899 Mon Sep 17 00:00:00 2001 From: Sean Young Date: Sat, 7 Aug 2021 22:45:35 +0100 Subject: mtd: rfd_ftl: add discard support I proposed this change 16 years ago before discard was a feature in the block layer: https://lwn.net/Articles/162776/ Now that the block layer has discard, we can finally merge this change. Discard is also known as trim. By implementing discard, both fstrim and the discard filesystem option can be used. Implementing discard in the ftl means that when files are removed, there is less data in the ftl mapping. This means less stuff to move around for erasing and also less erasing to do; this means improved wear levelling and improved performance. Signed-off-by: Sean Young Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210807214538.14484-3-sean@mess.org --- drivers/mtd/rfd_ftl.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'drivers/mtd') diff --git a/drivers/mtd/rfd_ftl.c b/drivers/mtd/rfd_ftl.c index 7b243f2b2fa3..7f5f6d247cae 100644 --- a/drivers/mtd/rfd_ftl.c +++ b/drivers/mtd/rfd_ftl.c @@ -705,6 +705,34 @@ err: return rc; } +static int rfd_ftl_discardsect(struct mtd_blktrans_dev *dev, + unsigned long sector, unsigned int nr_sects) +{ + struct partition *part = (struct partition *)dev; + u_long addr; + int rc; + + while (nr_sects) { + if (sector >= part->sector_count) + return -EIO; + + addr = part->sector_map[sector]; + + if (addr != -1) { + rc = mark_sector_deleted(part, addr); + if (rc) + return rc; + + part->sector_map[sector] = -1; + } + + sector++; + nr_sects--; + } + + return 0; +} + static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) { struct partition *part = (struct partition*)dev; @@ -786,6 +814,7 @@ static struct mtd_blktrans_ops rfd_ftl_tr = { .readsect = rfd_ftl_readsect, .writesect = rfd_ftl_writesect, + .discard = rfd_ftl_discardsect, .getgeo = rfd_ftl_getgeo, .add_mtd = rfd_ftl_add_mtd, .remove_dev = rfd_ftl_remove_dev, -- cgit v1.2.3-58-ga151