From 34b131849feb359f183907b467e9aa4d652b1baa Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 13 Jul 2012 20:35:12 -0500 Subject: [PATCH] rbd: add an rbd features field Record the features values for each rbd image and each of its snapshots. This is really something that only becomes meaningful for version 2 images, so this is just putting in place code that will form common infrastructure. It may be useful to expand the sysfs entries--and therefore the information we maintain--for the image and for each snapshot. But I'm going to hold off doing that until we start making active use of the feature bits. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- Documentation/ABI/testing/sysfs-bus-rbd | 7 ++++ drivers/block/rbd.c | 43 +++++++++++++++++++++++-- 2 files changed, 48 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-rbd b/Documentation/ABI/testing/sysfs-bus-rbd index 6fe4224cc5bd..1cf2adf46b11 100644 --- a/Documentation/ABI/testing/sysfs-bus-rbd +++ b/Documentation/ABI/testing/sysfs-bus-rbd @@ -25,6 +25,10 @@ client_id The ceph unique client id that was assigned for this specific session. +features + + A hexadecimal encoding of the feature bits for this image. + major The block device major number. @@ -78,4 +82,7 @@ snap_size The size of the image when this snapshot was taken. +snap_features + + A hexadecimal encoding of the feature bits for this snapshot. diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 8ac193ff4849..463f8b264c6f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -85,6 +85,7 @@ struct rbd_image_header { /* These four fields never change for a given rbd image */ char *object_prefix; + u64 features; __u8 obj_order; __u8 crypt_type; __u8 comp_type; @@ -148,12 +149,14 @@ struct rbd_snap { u64 size; struct list_head node; u64 id; + u64 features; }; struct rbd_mapping { char *snap_name; u64 snap_id; u64 size; + u64 features; bool snap_exists; bool read_only; }; @@ -590,6 +593,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->snap_sizes = NULL; } + header->features = 0; /* No features support in v1 images */ header->obj_order = ondisk->options.order; header->crypt_type = ondisk->options.crypt_type; header->comp_type = ondisk->options.comp_type; @@ -632,6 +636,7 @@ static int snap_by_name(struct rbd_device *rbd_dev, const char *snap_name) if (!strcmp(snap_name, snap->name)) { rbd_dev->mapping.snap_id = snap->id; rbd_dev->mapping.size = snap->size; + rbd_dev->mapping.features = snap->features; return 0; } @@ -648,6 +653,7 @@ static int rbd_dev_set_mapping(struct rbd_device *rbd_dev, char *snap_name) sizeof (RBD_SNAP_HEAD_NAME))) { rbd_dev->mapping.snap_id = CEPH_NOSNAP; rbd_dev->mapping.size = rbd_dev->header.image_size; + rbd_dev->mapping.features = rbd_dev->header.features; rbd_dev->mapping.snap_exists = false; rbd_dev->mapping.read_only = rbd_dev->rbd_opts.read_only; ret = 0; @@ -1835,6 +1841,19 @@ static ssize_t rbd_size_show(struct device *dev, return sprintf(buf, "%llu\n", (unsigned long long) size * SECTOR_SIZE); } +/* + * Note this shows the features for whatever's mapped, which is not + * necessarily the base image. + */ +static ssize_t rbd_features_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); + + return sprintf(buf, "0x%016llx\n", + (unsigned long long) rbd_dev->mapping.features); +} + static ssize_t rbd_major_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1884,6 +1903,10 @@ static ssize_t rbd_image_id_show(struct device *dev, return sprintf(buf, "%s\n", rbd_dev->image_id); } +/* + * Shows the name of the currently-mapped snapshot (or + * RBD_SNAP_HEAD_NAME for the base image). + */ static ssize_t rbd_snap_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -1907,6 +1930,7 @@ static ssize_t rbd_image_refresh(struct device *dev, } static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL); +static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL); static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL); static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL); static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL); @@ -1918,6 +1942,7 @@ static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL); static struct attribute *rbd_attrs[] = { &dev_attr_size.attr, + &dev_attr_features.attr, &dev_attr_major.attr, &dev_attr_client_id.attr, &dev_attr_pool.attr, @@ -1971,12 +1996,24 @@ static ssize_t rbd_snap_id_show(struct device *dev, return sprintf(buf, "%llu\n", (unsigned long long)snap->id); } +static ssize_t rbd_snap_features_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); + + return sprintf(buf, "0x%016llx\n", + (unsigned long long) snap->features); +} + static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL); static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL); +static DEVICE_ATTR(snap_features, S_IRUGO, rbd_snap_features_show, NULL); static struct attribute *rbd_snap_attrs[] = { &dev_attr_snap_size.attr, &dev_attr_snap_id.attr, + &dev_attr_snap_features.attr, NULL, }; @@ -2037,7 +2074,8 @@ static int rbd_register_snap_dev(struct rbd_snap *snap, static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev, const char *snap_name, - u64 snap_id, u64 snap_size) + u64 snap_id, u64 snap_size, + u64 snap_features) { struct rbd_snap *snap; int ret; @@ -2053,6 +2091,7 @@ static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev, snap->id = snap_id; snap->size = snap_size; + snap->features = snap_features; return snap; @@ -2123,7 +2162,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) /* We haven't seen this snapshot before */ new_snap = __rbd_add_snap_dev(rbd_dev, snap_name, - snap_id, header->snap_sizes[index]); + snap_id, header->snap_sizes[index], 0); if (IS_ERR(new_snap)) { int err = PTR_ERR(new_snap); -- 2.20.1