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From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Jeremy Allison <jra-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
	samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org,
	linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Volker Lendecke
	<Volker.Lendecke-PS7XAnAlDA+VvDNblw4Uiw@public.gmane.org>,
	Casey Bodley <cbodley-vtMw8L3fJ9vSiEDVxGk4TQ@public.gmane.org>,
	"J. Bruce Fields"
	<bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: [PATCH 4/4] locks: setlease cleanup
Date: Fri, 19 Aug 2011 12:07:51 -0400	[thread overview]
Message-ID: <1313770071-353-4-git-send-email-bfields@redhat.com> (raw)
In-Reply-To: <20110819160416.GC30856-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>

There's an incorrect comment here.  Also clean up the logic: the
"rdlease" and "wrlease" locals are confusingly named, and don't really
add anything since we can make a decision as soon as we hit one of these
cases.

Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 fs/locks.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index c525aa4..9b8408e 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1368,7 +1368,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 	struct file_lock *fl, **before, **my_before = NULL, *lease;
 	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
-	int error, rdlease_count = 0, wrlease_count = 0;
+	int error;
 
 	lease = *flp;
 
@@ -1404,27 +1404,28 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 	 * then the file is not open by anyone (including us)
 	 * except for this filp.
 	 */
+	error = -EAGAIN;
 	for (before = &inode->i_flock;
 			((fl = *before) != NULL) && IS_LEASE(fl);
 			before = &fl->fl_next) {
-		if (fl->fl_file == filp)
+		if (fl->fl_file == filp) {
 			my_before = before;
-		else if (fl->fl_flags & FL_UNLOCK_PENDING)
-			/*
-			 * Someone is in the process of opening this
-			 * file for writing so we may not take an
-			 * exclusive lease on it.
-			 */
-			wrlease_count++;
-		else
-			rdlease_count++;
+			continue;
+		}
+		/*
+		 * No exclusive leases if someone else has a lease on
+		 * this file:
+		 */
+		if (arg == F_WRLCK)
+			goto out;
+		/*
+		 * Modifying our existing lease is OK, but no getting a
+		 * new lease if someone else is opening for write:
+		 */
+		if (fl->fl_flags & FL_UNLOCK_PENDING)
+			goto out;
 	}
 
-	error = -EAGAIN;
-	if ((arg == F_RDLCK && (wrlease_count > 0)) ||
-	    (arg == F_WRLCK && ((rdlease_count + wrlease_count) > 0)))
-		goto out;
-
 	if (my_before != NULL) {
 		error = lease->fl_lmops->lm_change(my_before, arg);
 		if (!error)
-- 
1.7.4.1

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  parent reply	other threads:[~2011-08-19 16:07 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-09 23:16 [PATCH] locks: breaking read lease should not block read open J. Bruce Fields
2011-06-10  7:56 ` Volker Lendecke
     [not found]   ` <E1QUwaT-00HRZw-74-dqLtpHMqGvUyWpdLl23E4A@public.gmane.org>
2011-06-10 13:48     ` J. Bruce Fields
     [not found]       ` <20110610134859.GA27837-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-07-21  0:07         ` J. Bruce Fields
2011-07-21  0:15           ` Jeremy Allison
2011-07-21 16:35             ` J. Bruce Fields
2011-07-29  2:27               ` J. Bruce Fields
2011-07-29  2:29                 ` [PATCH 1/3] locks: minor lease cleanup J. Bruce Fields
     [not found]                   ` <20110729022911.GA23194-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-07-29  2:29                     ` [PATCH 2/3] locks: move F_INPROGRESS from fl_type to fl_flags field J. Bruce Fields
     [not found]                       ` <20110729022941.GB23194-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-07-29  2:30                         ` [PATCH 3/3] locks: fix tracking of inprogress lease breaks J. Bruce Fields
2011-08-19 16:04                 ` [PATCH] locks: breaking read lease should not block read open J. Bruce Fields
     [not found]                   ` <20110819160416.GC30856-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-08-19 16:07                     ` [PATCH 1/4] locks: minor lease cleanup J. Bruce Fields
2011-08-19 16:07                     ` [PATCH 2/4] locks: move F_INPROGRESS from fl_type to fl_flags field J. Bruce Fields
2011-08-19 16:07                     ` J. Bruce Fields [this message]
2011-08-19 16:07                   ` [PATCH 3/4] locks: fix tracking of inprogress lease breaks J. Bruce Fields
     [not found]           ` <20110721000758.GD27871-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-08-19 19:08             ` [PATCH] locks: breaking read lease should not block read open Jamie Lokier
2011-08-21 16:50               ` J. Bruce Fields
     [not found]                 ` <20110821165029.GA9296-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-11-21 12:46                   ` Jamie Lokier
2011-11-22 21:44                     ` J. Bruce Fields
     [not found]                       ` <20111122214441.GB23243-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2011-11-23  0:30                         ` Jamie Lokier
2011-11-23 19:08                           ` J. Bruce Fields

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