Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754157Ab3DOA4r (ORCPT ); Sun, 14 Apr 2013 20:56:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:39582 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753865Ab3DOA4q (ORCPT ); Sun, 14 Apr 2013 20:56:46 -0400 Date: Sun, 14 Apr 2013 19:56:31 -0500 From: Serge Hallyn To: Tejun Heo Cc: lizefan@huawei.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, mhocko@suse.cz, vgoyal@redhat.com, cgroups@vger.kernel.org Subject: Re: [PATCH 1/4] cgroup: convert cgroupfs_root flag bits to masks and add CGRP_ prefix Message-ID: <20130415005631.GB8408@sergelap> References: <1365808259-31073-1-git-send-email-tj@kernel.org> <1365808259-31073-2-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1365808259-31073-2-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4040 Lines: 107 Quoting Tejun Heo (tj@kernel.org): > There's no reason to be using bitops, which tends to be more > cumbersome, to handle root flags. Convert them to masks. Also, as > they'll be moved to include/linux/cgroup.h and it's generally a good > idea, add CGRP_ prefix. > > Note that flags are assigned from (1 << 1). The first bit will be > used by a flag which will be added soon. > > Signed-off-by: Tejun Heo This *is* much nicer to read, thanks. Acked-by: Serge E. Hallyn > --- > kernel/cgroup.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) > > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index 678a22c..a372eaa 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -296,10 +296,10 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor) > } > EXPORT_SYMBOL_GPL(cgroup_is_descendant); > > -/* bits in struct cgroupfs_root flags field */ > +/* cgroupfs_root->flags */ > enum { > - ROOT_NOPREFIX, /* mounted subsystems have no named prefix */ > - ROOT_XATTR, /* supports extended attributes */ > + CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ > + CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ > }; > > static int cgroup_is_releasable(const struct cgroup *cgrp) > @@ -1137,9 +1137,9 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry) > mutex_lock(&cgroup_root_mutex); > for_each_subsys(root, ss) > seq_printf(seq, ",%s", ss->name); > - if (test_bit(ROOT_NOPREFIX, &root->flags)) > + if (root->flags & CGRP_ROOT_NOPREFIX) > seq_puts(seq, ",noprefix"); > - if (test_bit(ROOT_XATTR, &root->flags)) > + if (root->flags & CGRP_ROOT_XATTR) > seq_puts(seq, ",xattr"); > if (strlen(root->release_agent_path)) > seq_printf(seq, ",release_agent=%s", root->release_agent_path); > @@ -1202,7 +1202,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) > continue; > } > if (!strcmp(token, "noprefix")) { > - set_bit(ROOT_NOPREFIX, &opts->flags); > + opts->flags |= CGRP_ROOT_NOPREFIX; > continue; > } > if (!strcmp(token, "clone_children")) { > @@ -1210,7 +1210,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) > continue; > } > if (!strcmp(token, "xattr")) { > - set_bit(ROOT_XATTR, &opts->flags); > + opts->flags |= CGRP_ROOT_XATTR; > continue; > } > if (!strncmp(token, "release_agent=", 14)) { > @@ -1293,8 +1293,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) > * with the old cpuset, so we allow noprefix only if mounting just > * the cpuset subsystem. > */ > - if (test_bit(ROOT_NOPREFIX, &opts->flags) && > - (opts->subsys_mask & mask)) > + if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask)) > return -EINVAL; > > > @@ -2523,7 +2522,7 @@ static struct simple_xattrs *__d_xattrs(struct dentry *dentry) > static inline int xattr_enabled(struct dentry *dentry) > { > struct cgroupfs_root *root = dentry->d_sb->s_fs_info; > - return test_bit(ROOT_XATTR, &root->flags); > + return root->flags & CGRP_ROOT_XATTR; > } > > static bool is_valid_xattr(const char *name) > @@ -2695,7 +2694,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, > > simple_xattrs_init(&cft->xattrs); > > - if (subsys && !test_bit(ROOT_NOPREFIX, &cgrp->root->flags)) { > + if (subsys && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) { > strcpy(name, subsys->name); > strcat(name, "."); > } > -- > 1.8.1.4 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/