Make sure that all callers of remount hold s_umount exclusive

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2009-05-05 23:48:50 -04:00
parent 5af7926ff3
commit 443b94baaa

View File

@ -579,7 +579,7 @@ static void do_emergency_remount(struct work_struct *work)
list_for_each_entry(sb, &super_blocks, s_list) { list_for_each_entry(sb, &super_blocks, s_list) {
sb->s_count++; sb->s_count++;
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
down_read(&sb->s_umount); down_write(&sb->s_umount);
if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) { if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
/* /*
* ->remount_fs needs lock_kernel(). * ->remount_fs needs lock_kernel().
@ -590,7 +590,8 @@ static void do_emergency_remount(struct work_struct *work)
do_remount_sb(sb, MS_RDONLY, NULL, 1); do_remount_sb(sb, MS_RDONLY, NULL, 1);
unlock_kernel(); unlock_kernel();
} }
drop_super(sb); up_write(&sb->s_umount);
put_super(sb);
spin_lock(&sb_lock); spin_lock(&sb_lock);
} }
spin_unlock(&sb_lock); spin_unlock(&sb_lock);