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author | Tejun Heo <tj@kernel.org> | 2015-08-18 14:55:31 -0700 |
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committer | Jens Axboe <axboe@fb.com> | 2015-08-18 15:49:18 -0700 |
commit | 36aa9e5f591e84d67aad2c5bff75e413d77660dd (patch) | |
tree | 228d8986be70359b086c30a453d1fc7ee77cfada /block/blk-cgroup.c | |
parent | 880f50e228f80626dff6327a6e281e40286f5228 (diff) | |
download | linux-36aa9e5f591e84d67aad2c5bff75e413d77660dd.tar.gz linux-36aa9e5f591e84d67aad2c5bff75e413d77660dd.tar.bz2 linux-36aa9e5f591e84d67aad2c5bff75e413d77660dd.zip |
blkcg: move body parsing from blkg_conf_prep() to its callers
Currently, blkg_conf_prep() expects input to be of the following form
MAJ:MIN NUM
and reads the NUM part into blkg_conf_ctx->v. This is quite
restrictive and gets in the way in implementing blkcg interface for
the unified hierarchy. This patch updates blkg_conf_prep() so that it
expects
MAJ:MIN BODY_STR
where BODY_STR is an arbitrary string. blkg_conf_ctx->v is replaced
with ->body which is a char pointer pointing to the start of BODY_STR.
Parsing of the body is moved to blkg_conf_prep()'s callers.
To allow using, for example, strsep() on blkg_conf_ctx->val, it is a
non-const pointer and to accommodate that const is dropped from @input
too.
This doesn't cause any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-cgroup.c')
-rw-r--r-- | block/blk-cgroup.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 429726bed560..8ee1ca4d4f2f 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -24,6 +24,7 @@ #include <linux/genhd.h> #include <linux/delay.h> #include <linux/atomic.h> +#include <linux/ctype.h> #include <linux/blk-cgroup.h> #include "blk.h" @@ -773,23 +774,28 @@ EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum); * @ctx: blkg_conf_ctx to be filled * * Parse per-blkg config update from @input and initialize @ctx with the - * result. @ctx->blkg points to the blkg to be updated and @ctx->v the new - * value. This function returns with RCU read lock and queue lock held and - * must be paired with blkg_conf_finish(). + * result. @ctx->blkg points to the blkg to be updated and @ctx->body the + * part of @input following MAJ:MIN. This function returns with RCU read + * lock and queue lock held and must be paired with blkg_conf_finish(). */ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, - const char *input, struct blkg_conf_ctx *ctx) + char *input, struct blkg_conf_ctx *ctx) __acquires(rcu) __acquires(disk->queue->queue_lock) { struct gendisk *disk; struct blkcg_gq *blkg; unsigned int major, minor; - unsigned long long v; - int part, ret; + int key_len, part, ret; + char *body; - if (sscanf(input, "%u:%u %llu", &major, &minor, &v) != 3) + 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); + disk = get_gendisk(MKDEV(major, minor), &part); if (!disk) return -ENODEV; @@ -826,7 +832,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, ctx->disk = disk; ctx->blkg = blkg; - ctx->v = v; + ctx->body = body; return 0; } EXPORT_SYMBOL_GPL(blkg_conf_prep); |