Adrian Hunter wrote:
From 328a858c01be1e0d08f4a4b1f43d9fd117a295e5 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Thu, 3 Jun 2010 10:46:04 +0300
Subject: [PATCH 1/4] block: Allow drivers to implement BLKDISCARD and add BLKSECDISCARD
SD/MMC cards provide an erase operation that is too inefficient to
allow file systems to use it, however it is still useful for
userspace tools because it is still 10 - 100 times faster than
writing zeroes. Allow the MMC block driver to provide its own
BLKDISCARD implementation for this purpose.
In addition, eMMC v4.4 cards can provide a secure erase operation
which guarantees that all copies of the discarded sectors (for
example created by garbage collection) will also be erased. For
this a new ioctl BLKSECDISCARD is added.
Ping?
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
block/compat_ioctl.c | 1 +
block/ioctl.c | 9 +++++++++
include/linux/fs.h | 1 +
3 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index f26051f..24a146d 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -753,6 +753,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
case BLKFLSBUF:
case BLKROSET:
case BLKDISCARD:
+ case BLKSECDISCARD:
/*
* the ones below are implemented in blkdev_locked_ioctl,
* but we call blkdev_ioctl, which gets the lock for us
diff --git a/block/ioctl.c b/block/ioctl.c
index e8eb679..985aa88 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -232,12 +232,21 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
if (!(mode & FMODE_WRITE))
return -EBADF;
+ ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ if (ret != -ENOTTY)
+ return ret;
+
if (copy_from_user(range, (void __user *)arg, sizeof(range)))
return -EFAULT;
return blk_ioctl_discard(bdev, range[0], range[1]);
}
+ case BLKSECDISCARD:
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+ return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+
case HDIO_GETGEO: {
struct hd_geometry geo;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3428393..25a6058 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -309,6 +309,7 @@ struct inodes_stat_t {
#define BLKALIGNOFF _IO(0x12,122)
#define BLKPBSZGET _IO(0x12,123)
#define BLKDISCARDZEROES _IO(0x12,124)
+#define BLKSECDISCARD _IO(0x12,125)
#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
#define FIBMAP _IO(0x00,1) /* bmap access */
--
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