From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:60921 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751015AbdE3Qbn (ORCPT ); Tue, 30 May 2017 12:31:43 -0400 From: Benjamin Coddington To: Alexander Viro , Jeff Layton , bfields@fieldses.org Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH v2 3/3] fs/locks: Use fs-specific l_pid for remote locks Date: Tue, 30 May 2017 12:31:40 -0400 Message-Id: In-Reply-To: References: In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org List-ID: Now that we're setting fl_nspid at file_lock allocation, we need to handle the case where a remote filesystem directly sets fl_pid. If the filesystem implements the lock operation, set a flag to return the lock's fl_pid, rather than fl_nspid. Signed-off-by: Benjamin Coddington --- fs/locks.c | 25 +++++++++++++++++++------ include/linux/fs.h | 7 +++++++ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 0f5a461b8da6..c7a222a8eaa7 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2047,16 +2047,28 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) */ int vfs_test_lock(struct file *filp, struct file_lock *fl) { - if (filp->f_op->lock && is_remote_lock(filp)) + if (filp->f_op->lock && is_remote_lock(filp)) { + fl->fl_flags |= FL_PID_PRIV; return filp->f_op->lock(filp, F_GETLK, fl); + } posix_test_lock(filp, fl); return 0; } EXPORT_SYMBOL_GPL(vfs_test_lock); +static inline int flock_translate_pid(struct file_lock *fl) +{ + if (IS_OFDLCK(fl)) + return -1; + if (fl->fl_flags & FL_PID_PRIV) + return fl->fl_pid; + return pid_vnr(fl->fl_nspid); +} + + static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) { - flock->l_pid = IS_OFDLCK(fl) ? -1 : fl->fl_pid; + flock->l_pid = flock_translate_pid(fl); #if BITS_PER_LONG == 32 /* * Make sure we can represent the posix lock via @@ -2078,7 +2090,7 @@ static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) #if BITS_PER_LONG == 32 static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) { - flock->l_pid = IS_OFDLCK(fl) ? -1 : fl->fl_pid; + flock->l_pid = flock_translate_pid(fl); flock->l_start = fl->fl_start; flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : fl->fl_end - fl->fl_start + 1; @@ -2596,7 +2608,9 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, struct inode *inode = NULL; unsigned int fl_pid; - if (fl->fl_nspid) { + if (fl->fl_flags & FL_PID_PRIV) { + fl_pid = fl->fl_pid; + } else { struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; /* Don't let fl_pid change based on who is reading the file */ @@ -2609,8 +2623,7 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, */ if (fl_pid == 0) return; - } else - fl_pid = fl->fl_pid; + } if (fl->fl_file != NULL) inode = locks_inode(fl->fl_file); diff --git a/include/linux/fs.h b/include/linux/fs.h index aa4affb38c39..11794cbaaed0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -908,6 +908,7 @@ static inline struct file *get_file(struct file *f) #define FL_UNLOCK_PENDING 512 /* Lease is being broken */ #define FL_OFDLCK 1024 /* lock is "owned" by struct file */ #define FL_LAYOUT 2048 /* outstanding pNFS layout */ +#define FL_PID_PRIV 4096 /* F_GETLK should report fl_pid */ #define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE) @@ -973,6 +974,12 @@ int opens_in_grace(struct net *); * 3) lock range end * * Obviously, the last two criteria only matter for POSIX locks. + * + * fl_pid and fl_nspid appear redundant, but fl_pid is used to handle cases + * where a local F_GETLK returns a lock that was granted to a remote owner, + * as might exist with a remotely available filesystem like NFS. For that + * case, the lock manager should set fl_pid, and that value is returned to a + * local F_GETLK. */ struct file_lock { struct file_lock *fl_next; /* singly linked list for this inode */ -- 2.9.3