path: root/drivers/mtd
diff options
authorTim Chen <>2011-07-19 09:32:38 -0700
committerAl Viro <>2011-07-24 10:08:32 -0400
commit423e0ab086ad8b33626e45fa94ac7613146b7ffa (patch)
tree249c9337a02254fe5dbede7436f78dfcc1ec508f /drivers/mtd
parentbbd9d6f7fbb0305c9a592bf05a32e87eb364a4ff (diff)
VFS : mount lock scalability for internal mounts
For a number of file systems that don't have a mount point (e.g. sockfs and pipefs), they are not marked as long term. Therefore in mntput_no_expire, all locks in vfs_mount lock are taken instead of just local cpu's lock to aggregate reference counts when we release reference to file objects. In fact, only local lock need to have been taken to update ref counts as these file systems are in no danger of going away until we are ready to unregister them. The attached patch marks file systems using kern_mount without mount point as long term. The contentions of vfs_mount lock is now eliminated. Before un-registering such file system, kern_unmount should be called to remove the long term flag and make the mount point ready to be freed. Signed-off-by: Tim Chen <> Signed-off-by: Al Viro <>
Diffstat (limited to 'drivers/mtd')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 3f92731a5b9e..f1af2228a1b1 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1192,7 +1192,7 @@ err_unregister_chdev:
static void __exit cleanup_mtdchar(void)
- mntput(mtd_inode_mnt);
+ kern_unmount(mtd_inode_mnt);
__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");