fs: protect inode->i_state with inode->i_lock

Protect inode state transitions and validity checks with the
inode->i_lock. This enables us to make inode state transitions
independently of the inode_lock and is the first step to peeling
away the inode_lock from the code.

This requires that __iget() is done atomically with i_state checks
during list traversals so that we don't race with another thread
marking the inode I_FREEING between the state check and grabbing the
reference.

Also remove the unlock_new_inode() memory barrier optimisation
required to avoid taking the inode_lock when clearing I_NEW.
Simplify the code by simply taking the inode->i_lock around the
state change and wakeup. Because the wakeup is no longer tricky,
remove the wake_up_inode() function and open code the wakeup where
necessary.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Dave Chinner
2011-03-22 22:23:36 +11:00
committed by Al Viro
parent 3dc8fe4dca
commit 250df6ed27
11 changed files with 176 additions and 76 deletions
+2
View File
@@ -56,9 +56,11 @@ static void bdev_inode_switch_bdi(struct inode *inode,
struct backing_dev_info *dst)
{
spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
inode->i_data.backing_dev_info = dst;
if (inode->i_state & I_DIRTY)
list_move(&inode->i_wb_list, &dst->wb.b_dirty);
spin_unlock(&inode->i_lock);
spin_unlock(&inode_lock);
}