Commit 21ac19d4 authored Nov 28, 2010 by Sergey Vlasov Committed by Trond Myklebust Dec 07, 2010

NFS: Fix fcntl F_GETLK not reporting some conflicts

The commit 129a84de (locks: fix F_GETLK
regression (failure to find conflicts)) fixed the posix_test_lock()
function by itself, however, its usage in NFS changed by the commit
9d6a8c5c (locks: give posix_test_lock
same interface as ->lock) remained broken - subsequent NFS-specific
locking code received F_UNLCK instead of the user-specified lock type.
To fix the problem, fl->fl_type needs to be saved before the
posix_test_lock() call and restored if no local conflicts were reported.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=23892


Tested-by: Alexander Morozov <amorozov@etersoft.ru>
Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Cc: <stable@kernel.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

parent 08a22b39

fs/nfs/file.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -693,6 +693,7 @@ do_getlk(struct file filp, int cmd, struct file_lock fl, int is_local)
		{
		struct inode *inode = filp->f_mapping->host;
		int status = 0;
		unsigned int saved_type = fl->fl_type;

		/* Try local locking first */
		posix_test_lock(filp, fl);
		@@ -700,6 +701,7 @@ do_getlk(struct file filp, int cmd, struct file_lock fl, int is_local)
		/* found a conflict */
		goto out;
		}
		fl->fl_type = saved_type;

		if (nfs_have_delegation(inode, FMODE_READ))
		goto out_noconflict;

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