From: Alex Elder Date: Fri, 26 Apr 2013 04:15:08 +0000 (-0500) Subject: rbd: have rbd_dev_image_id() set format 1 image id X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=c0fba36880288afbeca872298c970fb4abb76464;p=deliverable%2Flinux.git rbd: have rbd_dev_image_id() set format 1 image id Currently, rbd_dev_probe() assumes that any error returned by rbd_dev_image_id() is most likely -ENOENT, and responds by calling the format 1 probe routine, rbd_dev_v1_probe(). Then, at the top of rbd_dev_v1_probe(), an empty string is allocated for the image id. This is sort of unbalanced. Fix this by having rbd_dev_image_id() look for -ENOENT from its "get_id" method call. If that is seen, have it allocate the empty string there rather than depending on rbd_dev_v1_probe() to do it. Given that this is effectively defining the format of the image, set rbd_dev->image_format inside rbd_dev_image_id() rather than in the format-specific probe routines. Also drop a redundant hunk of code in rbd_dev_image_id(). Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 1704a3b1e4cb..0ddcbe584a1f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4477,20 +4477,19 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev) size_t size; char *object_name; void *response; - void *p; - - /* If we already have it we don't need to look it up */ - - if (rbd_dev->spec->image_id) - return 0; + char *image_id; /* * When probing a parent image, the image id is already * known (and the image name likely is not). There's no - * need to fetch the image id again in this case. + * need to fetch the image id again in this case. We + * do still need to set the image format though. */ - if (rbd_dev->spec->image_id) + if (rbd_dev->spec->image_id) { + rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1; + return 0; + } /* * First, see if the format 2 image id file exists, and if @@ -4512,24 +4511,32 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev) goto out; } + /* If it doesn't exist we'll assume it's a format 1 image */ + ret = rbd_obj_method_sync(rbd_dev, object_name, "rbd", "get_id", NULL, 0, response, RBD_IMAGE_ID_LEN_MAX, NULL); dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret); - if (ret < 0) - goto out; - - p = response; - rbd_dev->spec->image_id = ceph_extract_encoded_string(&p, - p + ret, + if (ret == -ENOENT) { + image_id = kstrdup("", GFP_KERNEL); + ret = image_id ? 0 : -ENOMEM; + if (!ret) + rbd_dev->image_format = 1; + } else if (ret > sizeof (__le32)) { + void *p = response; + + image_id = ceph_extract_encoded_string(&p, p + ret, NULL, GFP_NOIO); - ret = 0; - - if (IS_ERR(rbd_dev->spec->image_id)) { - ret = PTR_ERR(rbd_dev->spec->image_id); - rbd_dev->spec->image_id = NULL; + ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0; + if (!ret) + rbd_dev->image_format = 2; } else { - dout("image_id is %s\n", rbd_dev->spec->image_id); + ret = -EINVAL; + } + + if (!ret) { + rbd_dev->spec->image_id = image_id; + dout("image_id is %s\n", image_id); } out: kfree(response); @@ -4543,12 +4550,6 @@ static int rbd_dev_v1_probe(struct rbd_device *rbd_dev) int ret; size_t size; - /* Version 1 images have no id; empty string is used */ - - rbd_dev->spec->image_id = kstrdup("", GFP_KERNEL); - if (!rbd_dev->spec->image_id) - return -ENOMEM; - /* Record the header object name for this rbd image. */ size = strlen(rbd_dev->spec->image_name) + sizeof (RBD_SUFFIX); @@ -4571,8 +4572,6 @@ static int rbd_dev_v1_probe(struct rbd_device *rbd_dev) rbd_dev->parent_spec = NULL; rbd_dev->parent_overlap = 0; - rbd_dev->image_format = 1; - dout("discovered version 1 image, header name is %s\n", rbd_dev->header_name); @@ -4651,8 +4650,6 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) goto out_err; rbd_dev->header.obj_version = ver; - rbd_dev->image_format = 2; - dout("discovered version 2 image, header name is %s\n", rbd_dev->header_name); @@ -4795,6 +4792,11 @@ static int rbd_dev_probe(struct rbd_device *rbd_dev) */ ret = rbd_dev_image_id(rbd_dev); if (ret) + return ret; + rbd_assert(rbd_dev->spec->image_id); + rbd_assert(rbd_image_format_valid(rbd_dev->image_format)); + + if (rbd_dev->image_format == 1) ret = rbd_dev_v1_probe(rbd_dev); else ret = rbd_dev_v2_probe(rbd_dev);