shm: fix the filename of hugetlb sysv shared memory

Some user space tools need to identify SYSV shared memory when examining
/proc/<pid>/maps.  To do so they look for a block device with major zero, a
dentry named SYSV<sysv key>, and having the minor of the internal sysv
shared memory kernel mount.

To help these tools and to make it easier for people just browsing
/proc/<pid>/maps this patch modifies hugetlb sysv shared memory to use the
SYSV<key> dentry naming convention.

User space tools will still have to be aware that hugetlb sysv shared
memory lives on a different internal kernel mount and so has a different
block device minor number from the rest of sysv shared memory.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Albert Cahalan <acahalan@gmail.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
index 047b823..0852f20 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -366,9 +366,10 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
 		return error;
 	}
 
+	sprintf (name, "SYSV%08x", key);
 	if (shmflg & SHM_HUGETLB) {
-		/* hugetlb_zero_setup takes care of mlock user accounting */
-		file = hugetlb_zero_setup(size);
+		/* hugetlb_file_setup takes care of mlock user accounting */
+		file = hugetlb_file_setup(name, size);
 		shp->mlock_user = current->user;
 	} else {
 		int acctflag = VM_ACCOUNT;
@@ -379,7 +380,6 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
 		if  ((shmflg & SHM_NORESERVE) &&
 				sysctl_overcommit_memory != OVERCOMMIT_NEVER)
 			acctflag = 0;
-		sprintf (name, "SYSV%08x", key);
 		file = shmem_file_setup(name, size, acctflag);
 	}
 	error = PTR_ERR(file);