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authorTejun Heo <tj@kernel.org>2019-08-28 15:05:53 -0700
committerJens Axboe <axboe@kernel.dk>2019-08-28 21:17:04 -0600
commit015d254cb02b6d8eec4b3366274bf4672f9e0b64 (patch)
treea0157e4d1ded778a3aefe989666bf7151aeb0a1b /block
parent86a5bba5c252e90d264c7460e29a0b9e633777e7 (diff)
blkcg: separate blkcg_conf_get_disk() out of blkg_conf_prep()
Separate out blkcg_conf_get_disk() so that it can be used by blkcg policy interface file input parsers before the policy is actually enabled. This doesn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c62
1 files changed, 43 insertions, 19 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 78ccbdcfe723..0e2619c1a422 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -755,6 +755,44 @@ static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg,
/**
* blkg_conf_prep - parse and prepare for per-blkg config update
+ * @inputp: input string pointer
+ *
+ * Parse the device node prefix part, MAJ:MIN, of per-blkg config update
+ * from @input and get and return the matching gendisk. *@inputp is
+ * updated to point past the device node prefix. Returns an ERR_PTR()
+ * value on error.
+ *
+ * Use this function iff blkg_conf_prep() can't be used for some reason.
+ */
+struct gendisk *blkcg_conf_get_disk(char **inputp)
+{
+ char *input = *inputp;
+ unsigned int major, minor;
+ struct gendisk *disk;
+ int key_len, part;
+
+ if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2)
+ return ERR_PTR(-EINVAL);
+
+ input += key_len;
+ if (!isspace(*input))
+ return ERR_PTR(-EINVAL);
+ input = skip_spaces(input);
+
+ disk = get_gendisk(MKDEV(major, minor), &part);
+ if (!disk)
+ return ERR_PTR(-ENODEV);
+ if (part) {
+ put_disk_and_module(disk);
+ return ERR_PTR(-ENODEV);
+ }
+
+ *inputp = input;
+ return disk;
+}
+
+/**
+ * blkg_conf_prep - parse and prepare for per-blkg config update
* @blkcg: target block cgroup
* @pol: target policy
* @input: input string
@@ -772,25 +810,11 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
struct gendisk *disk;
struct request_queue *q;
struct blkcg_gq *blkg;
- unsigned int major, minor;
- int key_len, part, ret;
- char *body;
-
- if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2)
- return -EINVAL;
-
- body = input + key_len;
- if (!isspace(*body))
- return -EINVAL;
- body = skip_spaces(body);
+ int ret;
- disk = get_gendisk(MKDEV(major, minor), &part);
- if (!disk)
- return -ENODEV;
- if (part) {
- ret = -ENODEV;
- goto fail;
- }
+ disk = blkcg_conf_get_disk(&input);
+ if (IS_ERR(disk))
+ return PTR_ERR(disk);
q = disk->queue;
@@ -856,7 +880,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
success:
ctx->disk = disk;
ctx->blkg = blkg;
- ctx->body = body;
+ ctx->body = input;
return 0;
fail_unlock:

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