Patch "locks: don't check for race with close when setting OFD lock" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jan 11, 2018

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Stable branch VFS File locking (flock() and fcntl()/lockf())

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2018-01-11 14:04 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

locks: don't check for race with close when setting OFD lock

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
locks-don-t-check-for-race-with-close-when-setting-ofd-lock.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 0752ba807b04ccd69cb4bc8bbf829a80ee208a3c Mon Sep 17 00:00:00 2001

From: Jeff Layton <[email protected]>
Date: Fri, 8 Jan 2016 07:30:43 -0500
Subject: locks: don't check for race with close when setting OFD lock

From: Jeff Layton <[email protected]>

commit 0752ba807b04ccd69cb4bc8bbf829a80ee208a3c upstream.

We don't clean out OFD locks on close(), so there's no need to check for a race with them here. They'll get cleaned out at the same time that flock locks are.

Signed-off-by Jeff Layton <[email protected]>

Acked-by "J. Bruce Fields" <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

Signed-off-by Mel Gorman <[email protected]>

---
 fs/locks.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

fs/locks.c +10 -6

@@ -2220,10 +2220,12 @@ int fcntl_setlk(unsigned int fd, struct
 	error = do_lock_file_wait(filp, cmd, file_lock);
 
 	/*
-	 * Attempt to detect a close/fcntl race and recover by
-	 * releasing the lock that was just acquired.
+	 * Attempt to detect a close/fcntl race and recover by releasing the
+	 * lock that was just acquired. There is no need to do that when we're
+	 * unlocking though, or for OFD locks.
 	 */
-	if (!error && file_lock->fl_type != F_UNLCK) {
+	if (!error && file_lock->fl_type != F_UNLCK &&
+	    !(file_lock->fl_flags & FL_OFDLCK)) {
 		/*
 		 * We need that spin_lock here - it prevents reordering between
 		 * update of i_flctx->flc_posix and check for it done in

@@ -2362,10 +2364,12 @@ int fcntl_setlk64(unsigned int fd, struc
 	error = do_lock_file_wait(filp, cmd, file_lock);
 
 	/*
-	 * Attempt to detect a close/fcntl race and recover by
-	 * releasing the lock that was just acquired.
+	 * Attempt to detect a close/fcntl race and recover by releasing the
+	 * lock that was just acquired. There is no need to do that when we're
+	 * unlocking though, or for OFD locks.
 	 */
-	if (!error && file_lock->fl_type != F_UNLCK) {
+	if (!error && file_lock->fl_type != F_UNLCK &&
+	    !(file_lock->fl_flags & FL_OFDLCK)) {
 		/*
 		 * We need that spin_lock here - it prevents reordering between
 		 * update of i_flctx->flc_posix and check for it done in

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/locks-don-t-check-for-race-with-close-when-setting-ofd-lock.patch