From ff96128fb020e26e7b32e12e887013956d840f08 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 22 Jul 2014 21:53:07 +0400 Subject: rbd: show the entire chain of parent images Make /sys/bus/rbd/devices//parent show the entire chain of parent images. While at it, kernel sprintf() doesn't return negative values, casting to unsigned long long is no longer necessary and there is no good reason to split into multiple sprintf() calls. Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder --- drivers/block/rbd.c | 56 ++++++++++++++++++++++------------------------------- 1 file changed, 23 insertions(+), 33 deletions(-) (limited to 'drivers/block/rbd.c') diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 703b728e05fa..7847fbb949ff 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3685,46 +3685,36 @@ static ssize_t rbd_snap_show(struct device *dev, } /* - * For an rbd v2 image, shows the pool id, image id, and snapshot id - * for the parent image. If there is no parent, simply shows - * "(no parent image)". + * For a v2 image, shows the chain of parent images, separated by empty + * lines. For v1 images or if there is no parent, shows "(no parent + * image)". */ static ssize_t rbd_parent_show(struct device *dev, - struct device_attribute *attr, - char *buf) + struct device_attribute *attr, + char *buf) { struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); - struct rbd_spec *spec = rbd_dev->parent_spec; - int count; - char *bufp = buf; + ssize_t count = 0; - if (!spec) + if (!rbd_dev->parent) return sprintf(buf, "(no parent image)\n"); - count = sprintf(bufp, "pool_id %llu\npool_name %s\n", - (unsigned long long) spec->pool_id, spec->pool_name); - if (count < 0) - return count; - bufp += count; - - count = sprintf(bufp, "image_id %s\nimage_name %s\n", spec->image_id, - spec->image_name ? spec->image_name : "(unknown)"); - if (count < 0) - return count; - bufp += count; - - count = sprintf(bufp, "snap_id %llu\nsnap_name %s\n", - (unsigned long long) spec->snap_id, spec->snap_name); - if (count < 0) - return count; - bufp += count; - - count = sprintf(bufp, "overlap %llu\n", rbd_dev->parent_overlap); - if (count < 0) - return count; - bufp += count; - - return (ssize_t) (bufp - buf); + for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) { + struct rbd_spec *spec = rbd_dev->parent_spec; + + count += sprintf(&buf[count], "%s" + "pool_id %llu\npool_name %s\n" + "image_id %s\nimage_name %s\n" + "snap_id %llu\nsnap_name %s\n" + "overlap %llu\n", + !count ? "" : "\n", /* first? */ + spec->pool_id, spec->pool_name, + spec->image_id, spec->image_name ?: "(unknown)", + spec->snap_id, spec->snap_name, + rbd_dev->parent_overlap); + } + + return count; } static ssize_t rbd_image_refresh(struct device *dev, -- cgit v1.2.3