Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f46.google.com ([209.85.216.46]:44155 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751576AbaHSSiq (ORCPT ); Tue, 19 Aug 2014 14:38:46 -0400 Received: by mail-qa0-f46.google.com with SMTP id v10so5935876qac.33 for ; Tue, 19 Aug 2014 11:38:41 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 3/5] nfsd: add a v4_end_grace file to /proc/fs/nfsd Date: Tue, 19 Aug 2014 14:38:27 -0400 Message-Id: <1408473509-14010-4-git-send-email-jlayton@primarydata.com> In-Reply-To: <1408473509-14010-1-git-send-email-jlayton@primarydata.com> References: <1408473509-14010-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Allow a privileged userland process to end the v4 grace period early. Any write to the file will cause the v4 grace period to be lifted. The basic idea with this will be to allow the userland client tracking program to lift the grace period once it knows that no more clients will be reclaiming state. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 2 +- fs/nfsd/nfsctl.c | 35 +++++++++++++++++++++++++++++++++++ fs/nfsd/state.h | 3 +++ 3 files changed, 39 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 2e80a59e7e91..711280e0e4ac 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4107,7 +4107,7 @@ out: return status; } -static void +void nfsd4_end_grace(struct nfsd_net *nn) { /* do nothing if grace period already ended */ diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 4e042105fb6e..99044e237861 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -49,6 +49,7 @@ enum { NFSD_Leasetime, NFSD_Gracetime, NFSD_RecoveryDir, + NFSD_V4EndGrace, #endif }; @@ -68,6 +69,7 @@ static ssize_t write_maxconn(struct file *file, char *buf, size_t size); static ssize_t write_leasetime(struct file *file, char *buf, size_t size); static ssize_t write_gracetime(struct file *file, char *buf, size_t size); static ssize_t write_recoverydir(struct file *file, char *buf, size_t size); +static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size); #endif static ssize_t (*write_op[])(struct file *, char *, size_t) = { @@ -84,6 +86,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = { [NFSD_Leasetime] = write_leasetime, [NFSD_Gracetime] = write_gracetime, [NFSD_RecoveryDir] = write_recoverydir, + [NFSD_V4EndGrace] = write_v4_end_grace, #endif }; @@ -1077,6 +1080,37 @@ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size) return rv; } +/** + * write_v4_end_grace - release grace period for nfsd's v4.x lock manager + * + * Input: + * buf: ignored + * size: zero + * OR + * + * Input: + * buf: any value + * size: non-zero length of C string in @buf + * Output: + * passed-in buffer filled with "Y" or "N" with a newline + * and NULL-terminated C string. This indicates whether + * the grace period has ended in the current net + * namespace. Return code is the size in bytes of the + * string. Writing to the file will end the grace period + * for nfsd's v4 lock manager. + */ +static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size) +{ + struct net *net = file->f_dentry->d_sb->s_fs_info; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + if (size > 0) + nfsd4_end_grace(nn); + + return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n", + nn->grace_ended ? 'Y' : 'N'); +} + #endif /*----------------------------------------------------------------------------*/ @@ -1110,6 +1144,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR}, + [NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO}, #endif /* last one */ {""} }; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 4a89e00d7461..ecf579904892 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -545,6 +545,9 @@ extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name, struct nfsd_net *nn); extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn); +/* grace period management */ +void nfsd4_end_grace(struct nfsd_net *nn); + /* nfs4recover operations */ extern int nfsd4_client_tracking_init(struct net *net); extern void nfsd4_client_tracking_exit(struct net *net); -- 1.9.3