diff options
Diffstat (limited to 'drivers/md/bitmap.c')
| -rw-r--r-- | drivers/md/bitmap.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index c7784a98567..ac688fb54e1 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -1934,6 +1934,44 @@ location_store(struct mddev *mddev, const char *buf, size_t len) static struct md_sysfs_entry bitmap_location = __ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store); +/* 'bitmap/space' is the space available at 'location' for the + * bitmap. This allows the kernel to know when it is safe to + * resize the bitmap to match a resized array. + */ +static ssize_t +space_show(struct mddev *mddev, char *page) +{ + return sprintf(page, "%lu\n", mddev->bitmap_info.space); +} + +static ssize_t +space_store(struct mddev *mddev, const char *buf, size_t len) +{ + unsigned long sectors; + int rv; + + rv = kstrtoul(buf, 10, §ors); + if (rv) + return rv; + + if (sectors == 0) + return -EINVAL; + + if (mddev->bitmap && + sectors < ((mddev->bitmap->file_pages - 1) * PAGE_SIZE + + mddev->bitmap->last_page_size + 511) >> 9) + return -EFBIG; /* Bitmap is too big for this small space */ + + /* could make sure it isn't too big, but that isn't really + * needed - user-space should be careful. + */ + mddev->bitmap_info.space = sectors; + return len; +} + +static struct md_sysfs_entry bitmap_space = +__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store); + static ssize_t timeout_show(struct mddev *mddev, char *page) { @@ -2109,6 +2147,7 @@ __ATTR(max_backlog_used, S_IRUGO | S_IWUSR, static struct attribute *md_bitmap_attrs[] = { &bitmap_location.attr, + &bitmap_space.attr, &bitmap_timeout.attr, &bitmap_backlog.attr, &bitmap_chunksize.attr, |