Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753966Ab2KSSFL (ORCPT ); Mon, 19 Nov 2012 13:05:11 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47077 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752909Ab2KSSFK (ORCPT ); Mon, 19 Nov 2012 13:05:10 -0500 Date: Mon, 19 Nov 2012 12:04:58 -0600 From: Serge Hallyn To: "Eric W. Biederman" Cc: Linux Containers , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH review 14/16] proc: Generalize proc inode allocation Message-ID: <20121119180458.GD1883@serge-ThinkPad-X130e> References: <87lidx8wbo.fsf@xmission.com> <1353337961-12962-1-git-send-email-ebiederm@xmission.com> <1353337961-12962-14-git-send-email-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1353337961-12962-14-git-send-email-ebiederm@xmission.com> 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: 4041 Lines: 132 Quoting Eric W. Biederman (ebiederm@xmission.com): > From: "Eric W. Biederman" > > 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 E. Hallyn > --- > 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 0d80cef..7b3ae3c 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) { > @@ -764,7 +764,7 @@ 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 3144781..bf1d000 100644 > --- a/include/linux/proc_fs.h > +++ b/include/linux/proc_fs.h > @@ -176,6 +176,8 @@ extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, > extern struct file *proc_ns_fget(int fd); > extern bool proc_ns_inode(struct inode *inode); > > +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; }) > @@ -235,6 +237,14 @@ static inline bool proc_ns_inode(struct inode *inode) > return false; > } > > +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) > -- > 1.7.5.4 > > _______________________________________________ > 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/