From 51344a38ba2033be18a4ec23e318845caeccdc04 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Mon, 6 May 2013 07:40:30 -0500 Subject: [PATCH] rbd: always set read-only flag in rbd_add() Hold off setting the read-only flag in rbd_add() for an image being mapped until we have successfully probed the image. At that point we know whether it's a snapshot mapping or not, so we can set the read-only flag in that one place rather than doing so (for snapshots) in rbd_dev_mapping_set(). To do this, pass a flag to the image probe routine indicating whether we want a read-only mapping. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index a62e59a0aea7..b5cac7931ffc 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -359,7 +359,7 @@ static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count); static ssize_t rbd_remove(struct bus_type *bus, const char *buf, size_t count); -static int rbd_dev_image_probe(struct rbd_device *rbd_dev); +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool read_only); static struct bus_attribute rbd_bus_attrs[] = { __ATTR(add, S_IWUSR, NULL, rbd_add), @@ -951,11 +951,6 @@ static int rbd_dev_mapping_set(struct rbd_device *rbd_dev) rbd_dev->mapping.size = size; rbd_dev->mapping.features = features; - /* If we are mapping a snapshot it must be marked read-only */ - - if (snap_id != CEPH_NOSNAP) - rbd_dev->mapping.read_only = true; - return 0; } @@ -963,7 +958,6 @@ static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev) { rbd_dev->mapping.size = 0; rbd_dev->mapping.features = 0; - rbd_dev->mapping.read_only = true; } static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) @@ -4620,7 +4614,7 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev) if (!parent) goto out_err; - ret = rbd_dev_image_probe(parent); + ret = rbd_dev_image_probe(parent, true); if (ret < 0) goto out_err; rbd_dev->parent = parent; @@ -4743,7 +4737,7 @@ static void rbd_dev_image_release(struct rbd_device *rbd_dev) * device. For format 2 images this includes determining the image * id. */ -static int rbd_dev_image_probe(struct rbd_device *rbd_dev) +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool read_only) { int ret; int tmp; @@ -4778,6 +4772,12 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) if (ret) goto err_out_probe; + /* If we are mapping a snapshot it must be marked read-only */ + + if (rbd_dev->spec->snap_id != CEPH_NOSNAP) + read_only = true; + rbd_dev->mapping.read_only = read_only; + ret = rbd_dev_probe_parent(rbd_dev); if (!ret) return 0; @@ -4811,6 +4811,7 @@ static ssize_t rbd_add(struct bus_type *bus, struct rbd_spec *spec = NULL; struct rbd_client *rbdc; struct ceph_osd_client *osdc; + bool read_only; int rc = -ENOMEM; if (!try_module_get(THIS_MODULE)) @@ -4820,6 +4821,9 @@ static ssize_t rbd_add(struct bus_type *bus, rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec); if (rc < 0) goto err_out_module; + read_only = rbd_opts->read_only; + kfree(rbd_opts); + rbd_opts = NULL; /* done with this */ rbdc = rbd_get_client(ceph_opts); if (IS_ERR(rbdc)) { @@ -4850,11 +4854,7 @@ static ssize_t rbd_add(struct bus_type *bus, rbdc = NULL; /* rbd_dev now owns this */ spec = NULL; /* rbd_dev now owns this */ - rbd_dev->mapping.read_only = rbd_opts->read_only; - kfree(rbd_opts); - rbd_opts = NULL; /* done with this */ - - rc = rbd_dev_image_probe(rbd_dev); + rc = rbd_dev_image_probe(rbd_dev, read_only); if (rc < 0) goto err_out_rbd_dev; -- 2.20.1