Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754148Ab1FSOUV (ORCPT ); Sun, 19 Jun 2011 10:20:21 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:33292 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754052Ab1FSOUR (ORCPT ); Sun, 19 Jun 2011 10:20:17 -0400 X-Authority-Analysis: v=1.1 cv=PfPQ8rIoTcZsncbPZjVSZ7K0hy8Zc4hmL68r4VPNpKE= c=1 sm=0 a=wom5GMh1gUkA:10 a=GEPW4q0ZuoIA:10 a=Rj1_iGo3bfgA:10 a=kj9zAlcOel0A:10 a=g3F5VGk0NOMZWSIEWMgijA==:17 a=PtDNVHqPAAAA:8 a=hBqU3vQJAAAA:8 a=vQgLKLE2k9J-kVW9TckA:9 a=NsZA2_Rz0CG542eln4kA:7 a=CjuIK1q_8ugA:10 a=wYE_KDyynt4A:10 a=4gZ4WExUoD4A:10 a=7HssHgY2OuPQguJh:21 a=t8d2NfIxdw4J_3ZD:21 a=g3F5VGk0NOMZWSIEWMgijA==:117 X-Cloudmark-Score: 0 X-Originating-IP: 70.123.158.191 Date: Sun, 19 Jun 2011 09:20:14 -0500 From: "Serge E. Hallyn" To: "Eric W. Biederman" Cc: Linux Containers , Alexey Dobriyan , netdev@vger.kernel.org, David Lamparter , linux-kernel@vger.kernel.org, "Serge E. Hallyn" Subject: Re: [PATCH 1/2] proc: Generalize proc inode allocation Message-ID: <20110619142014.GA4694@mail.hallyn.com> References: <20110521093936.GA3015@p183> <20110521223054.GA3198@p183> <20110523014303.GA2351982@jupiter.n2.diac24.net> <20110523014751.GB2351982@jupiter.n2.diac24.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 3862 Lines: 131 Quoting Eric W. Biederman (ebiederm@xmission.com): > > Generalize the proc inode allocation so that it can be > used without having to having to create a proc_dir_entry. > > This will allow namespace file descriptors to remain light > weight entitities but still have the same inode number > when the backing namespace is the same. > > Signed-off-by: Eric W. Biederman Acked-by: Serge Hallyn > --- > > Baring problems in review I plan to merge these patches > via my linux-2.6-nsfd tree. > > fs/proc/generic.c | 26 +++++++++++++------------- > include/linux/proc_fs.h | 10 ++++++++++ > 2 files changed, 23 insertions(+), 13 deletions(-) > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > index f1637f1..65416a1 100644 > --- a/fs/proc/generic.c > +++ b/fs/proc/generic.c > @@ -350,14 +350,14 @@ static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */ > * Return an inode number between PROC_DYNAMIC_FIRST and > * 0xffffffff, or zero on failure. > */ > -static unsigned int get_inode_number(void) > +int proc_alloc_inum(unsigned int *inum) > { > unsigned int i; > int error; > > retry: > - if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0) > - return 0; > + if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL)) > + return -ENOMEM; > > spin_lock(&proc_inum_lock); > error = ida_get_new(&proc_inum_ida, &i); > @@ -365,18 +365,19 @@ retry: > if (error == -EAGAIN) > goto retry; > else if (error) > - return 0; > + return error; > > if (i > UINT_MAX - PROC_DYNAMIC_FIRST) { > spin_lock(&proc_inum_lock); > ida_remove(&proc_inum_ida, i); > spin_unlock(&proc_inum_lock); > - return 0; > + return -ENOSPC; > } > - return PROC_DYNAMIC_FIRST + i; > + *inum = PROC_DYNAMIC_FIRST + i; > + return 0; > } > > -static void release_inode_number(unsigned int inum) > +void proc_free_inum(unsigned int inum) > { > spin_lock(&proc_inum_lock); > ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST); > @@ -554,13 +555,12 @@ static const struct inode_operations proc_dir_inode_operations = { > > static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) > { > - unsigned int i; > struct proc_dir_entry *tmp; > + int ret; > > - i = get_inode_number(); > - if (i == 0) > - return -EAGAIN; > - dp->low_ino = i; > + ret = proc_alloc_inum(&dp->low_ino); > + if (ret) > + return ret; > > if (S_ISDIR(dp->mode)) { > if (dp->proc_iops == NULL) { > @@ -766,7 +766,7 @@ EXPORT_SYMBOL(proc_create_data); > > static void free_proc_entry(struct proc_dir_entry *de) > { > - release_inode_number(de->low_ino); > + proc_free_inum(de->low_ino); > > if (S_ISLNK(de->mode)) > kfree(de->data); > diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h > index e7576cf..3067b44 100644 > --- a/include/linux/proc_fs.h > +++ b/include/linux/proc_fs.h > @@ -175,6 +175,8 @@ extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, > > extern struct file *proc_ns_fget(int fd); > > +extern int proc_alloc_inum(unsigned int *pino); > +extern void proc_free_inum(unsigned int inum); > #else > > #define proc_net_fops_create(net, name, mode, fops) ({ (void)(mode), NULL; }) > @@ -229,6 +231,14 @@ static inline struct file *proc_ns_fget(int fd) > return ERR_PTR(-EINVAL); > } > > +static inline int proc_alloc_inum(unsigned int *inum) > +{ > + *inum = 1; > + return 0; > +} > +static inline void proc_free_inum(unsigned int inum) > +{ > +} > #endif /* CONFIG_PROC_FS */ > > #if !defined(CONFIG_PROC_KCORE) > -- > 1.7.5.1.217.g4e3aa > -- 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/