Commit ef1ff6b8 authored Sep 23, 2009 by From: Mel Gorman Committed by Linus Torvalds Sep 24, 2009

hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fix



Commit 6bfde05b ("hugetlbfs: allow the creation of files suitable for
MAP_PRIVATE on the vfs internal mount") altered can_do_hugetlb_shm() to
check if a file is being created for shared memory or mmap().  If this
returns false, we then unconditionally call user_shm_lock() triggering a
warning.  This block should never be entered for MAP_HUGETLB.  This
patch partially reverts the problem and fixes the check.

Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 2c6854fd

fs/hugetlbfs/inode.c

+3 −9

Original line number	Diff line number	Diff line
		@@ -936,15 +936,9 @@ static struct file_system_type hugetlbfs_fs_type = {

		static struct vfsmount *hugetlbfs_vfsmount;

		static int can_do_hugetlb_shm(int creat_flags)
		static int can_do_hugetlb_shm(void)
		{
		if (creat_flags != HUGETLB_SHMFS_INODE)
		return 0;
		if (capable(CAP_IPC_LOCK))
		return 1;
		if (in_group_p(sysctl_hugetlb_shm_group))
		return 1;
		return 0;
		return capable(CAP_IPC_LOCK) \|\| in_group_p(sysctl_hugetlb_shm_group);
		}

		struct file hugetlb_file_setup(const char name, size_t size, int acctflag,
		@@ -960,7 +954,7 @@ struct file hugetlb_file_setup(const char name, size_t size, int acctflag,
		if (!hugetlbfs_vfsmount)
		return ERR_PTR(-ENOENT);

		if (!can_do_hugetlb_shm(creat_flags)) {
		if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
		*user = current_user();
		if (user_shm_lock(size, *user)) {
		WARN_ONCE(1,

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