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authorMiklos Szeredi <mszeredi@suse.cz>2011-11-21 12:11:30 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2012-01-06 23:20:12 -0500
commit39f7c4db1d2d9e2e2a90abdf34811783089d217d (patch)
treecbc3496ce21e26b5891bb4c4d4155853317ddfb3 /fs
parent34c80b1d93e6e20ca9dea0baf583a5b5510d92d4 (diff)
vfs: keep list of mounts for each superblock
Keep track of vfsmounts belonging to a superblock. List is protected by vfsmount_lock. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/mount.h1
-rw-r--r--fs/namespace.c7
-rw-r--r--fs/super.c2
3 files changed, 10 insertions, 0 deletions
diff --git a/fs/mount.h b/fs/mount.h
index 0921b51e27e..4ef36d93e5a 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -29,6 +29,7 @@ struct mount {
#endif
struct list_head mnt_mounts; /* list of children, anchored here */
struct list_head mnt_child; /* and going through their mnt_child */
+ struct list_head mnt_instance; /* mount instance on sb->s_mounts */
const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
struct list_head mnt_list;
struct list_head mnt_expire; /* link in fs-specific expiry list */
diff --git a/fs/namespace.c b/fs/namespace.c
index db65e2e4921..145217b088d 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -671,6 +671,9 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
mnt->mnt.mnt_sb = root->d_sb;
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
return &mnt->mnt;
}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
@@ -699,6 +702,9 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
mnt->mnt.mnt_root = dget(root);
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
if (flag & CL_SLAVE) {
list_add(&mnt->mnt_slave, &old->mnt_slave_list);
@@ -781,6 +787,7 @@ put_again:
acct_auto_close_mnt(&mnt->mnt);
goto put_again;
}
+ list_del(&mnt->mnt_instance);
br_write_unlock(vfsmount_lock);
mntfree(mnt);
}
diff --git a/fs/super.c b/fs/super.c
index 0413f51a9f0..993ca8f128d 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -142,6 +142,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
INIT_LIST_HEAD(&s->s_dentry_lru);
INIT_LIST_HEAD(&s->s_inode_lru);
spin_lock_init(&s->s_inode_lru_lock);
+ INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
mutex_init(&s->s_lock);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
@@ -200,6 +201,7 @@ static inline void destroy_super(struct super_block *s)
free_percpu(s->s_files);
#endif
security_sb_free(s);
+ WARN_ON(!list_empty(&s->s_mounts));
kfree(s->s_subtype);
kfree(s->s_options);
kfree(s);