From 83303b613d00718b07ec0a4dee7c99aa66629d96 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 6 Jan 2006 00:21:06 -0800 Subject: [PATCH] [PATCH] md: allow available size of component devices to be set via sysfs Signed-off-by: Neil Brown Acked-by: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/md.txt | 7 +++++++ drivers/md/md.c | 25 +++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/Documentation/md.txt b/Documentation/md.txt index 866a1a887547..7b3d471bb9f0 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -250,6 +250,13 @@ Each directory contains: the device before this offset us not touched, unless it is used for storing metadata (Formats 1.1 and 1.2). + size + The amount of the device, after the offset, that can be used + for storage of data. This will normally be the same as the + component_size. This can be written while assembling an + array. If a value less than the current component_size is + written, component_size will be reduced to this value. + An active md device will also contain and entry for each active device in the array. These are named diff --git a/drivers/md/md.c b/drivers/md/md.c index 27db100d8b12..40ac7fbab61f 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1686,12 +1686,37 @@ offset_store(mdk_rdev_t *rdev, const char *buf, size_t len) static struct rdev_sysfs_entry rdev_offset = __ATTR(offset, 0644, offset_show, offset_store); +static ssize_t +rdev_size_show(mdk_rdev_t *rdev, char *page) +{ + return sprintf(page, "%llu\n", (unsigned long long)rdev->size); +} + +static ssize_t +rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len) +{ + char *e; + unsigned long long size = simple_strtoull(buf, &e, 10); + if (e==buf || (*e && *e != '\n')) + return -EINVAL; + if (rdev->mddev->pers) + return -EBUSY; + rdev->size = size; + if (size < rdev->mddev->size || rdev->mddev->size == 0) + rdev->mddev->size = size; + return len; +} + +static struct rdev_sysfs_entry rdev_size = +__ATTR(size, 0644, rdev_size_show, rdev_size_store); + static struct attribute *rdev_default_attrs[] = { &rdev_state.attr, &rdev_super.attr, &rdev_errors.attr, &rdev_slot.attr, &rdev_offset.attr, + &rdev_size.attr, NULL, }; static ssize_t -- 2.30.2