xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

cgroup: replace cftype->write_string() with cftype->write()

Browse Source 
Convert all cftype->write_string() users to the new cftype->write()
which maps directly to kernfs write operation and has full access to
kernfs and cgroup contexts.  The conversions are mostly mechanical.

* @css and @cft are accessed using of_css() and of_cft() accessors
  respectively instead of being specified as arguments.

* Should return @nbytes on success instead of 0.

* @buf is not trimmed automatically.  Trim if necessary.  Note that
  blkcg and netprio don't need this as the parsers already handle
  whitespaces.

cftype->write_string() has no user left after the conversions and
removed.

While at it, remove unnecessary local variable @p in
cgroup_subtree_control_write() and stale comment about
CGROUP_LOCAL_BUFFER_SIZE in cgroup_freezer.c.

This patch doesn't introduce any visible behavior changes.

v2: netprio was missing from conversion.  Converted.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Aristeu Rozanski <arozansk@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
This commit is contained in:
Tejun Heo
2014-05-13 12:16:21 -04:00
parent b41686401e
commit 451af504df
11 changed files with 124 additions and 125 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/linux/cgroup.h
View File

@@ -453,8 +453,7 @@ struct cftype {
/*
* The maximum length of string, excluding trailing nul, that can
* be passed to write_string. If < PAGE_SIZE-1, PAGE_SIZE-1 is
* assumed.
* be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
*/
size_t max_write_len;
@@ -500,13 +499,6 @@ struct cftype {
int (*write_s64)(struct cgroup_subsys_state *css, struct cftype *cft,
s64 val);
/*
* write_string() is passed a nul-terminated kernelspace
* buffer of maximum length determined by max_write_len.
* Returns 0 or -ve error code.
*/
int (*write_string)(struct cgroup_subsys_state *css, struct cftype *cft,
char *buffer);
/*
* trigger() callback can be used to get some kick from the
* userspace, when the actual string written is not important