Revert "vfs: Don't evict inode under the inode lru traversing context"

This reverts commit 03880af.

Signed-off-by: Suraj Jitindar Singh <[email protected]>

Author: Suraj Jitindar Singh

fs/inode.c

@@ -453,39 +453,6 @@ static void inode_lru_list_del(struct inode *inode)
 		this_cpu_dec(nr_unused);
 }
 
-static void inode_pin_lru_isolating(struct inode *inode)
-{
-	lockdep_assert_held(&inode->i_lock);
-	WARN_ON(inode->i_state & (I_LRU_ISOLATING | I_FREEING | I_WILL_FREE));
-	inode->i_state |= I_LRU_ISOLATING;
-}
-
-static void inode_unpin_lru_isolating(struct inode *inode)
-{
-	spin_lock(&inode->i_lock);
-	WARN_ON(!(inode->i_state & I_LRU_ISOLATING));
-	inode->i_state &= ~I_LRU_ISOLATING;
-	smp_mb();
-	wake_up_bit(&inode->i_state, __I_LRU_ISOLATING);
-	spin_unlock(&inode->i_lock);
-}
-
-static void inode_wait_for_lru_isolating(struct inode *inode)
-{
-	spin_lock(&inode->i_lock);
-	if (inode->i_state & I_LRU_ISOLATING) {
-		DEFINE_WAIT_BIT(wq, &inode->i_state, __I_LRU_ISOLATING);
-		wait_queue_head_t *wqh;
-
-		wqh = bit_waitqueue(&inode->i_state, __I_LRU_ISOLATING);
-		spin_unlock(&inode->i_lock);
-		__wait_on_bit(wqh, &wq, bit_wait, TASK_UNINTERRUPTIBLE);
-		spin_lock(&inode->i_lock);
-		WARN_ON(inode->i_state & I_LRU_ISOLATING);
-	}
-	spin_unlock(&inode->i_lock);
-}
-
 /**
  * inode_sb_list_add - add inode to the superblock list of inodes
  * @inode: inode to add
@@ -598,8 +565,6 @@ static void evict(struct inode *inode)
 
 	inode_sb_list_del(inode);
 
-	inode_wait_for_lru_isolating(inode);
-
 	/*
 	 * Wait for flusher thread to be done with the inode so that filesystem
 	 * does not start destroying it while writeback is still running. Since
@@ -803,7 +768,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 	}
 
 	if (inode_has_buffers(inode) || inode->i_data.nrpages) {
-		inode_pin_lru_isolating(inode);
+		__iget(inode);
 		spin_unlock(&inode->i_lock);
 		spin_unlock(lru_lock);
 		if (remove_inode_buffers(inode)) {
@@ -816,7 +781,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 			if (current->reclaim_state)
 				current->reclaim_state->reclaimed_slab += reap;
 		}
-		inode_unpin_lru_isolating(inode);
+		iput(inode);
 		spin_lock(lru_lock);
 		return LRU_RETRY;
 	}

include/linux/fs.h

@@ -2286,9 +2286,6 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
  *			Used to detect that mark_inode_dirty() should not move
  * 			inode between dirty lists.
  *
- * I_LRU_ISOLATING	Inode is pinned being isolated from LRU without holding
- *			i_count.
- *
  * Q: What is the difference between I_WILL_FREE and I_FREEING?
  */
 #define I_DIRTY_SYNC		(1 << 0)
@@ -2311,8 +2308,6 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
 #define I_CREATING		(1 << 15)
 #define I_DONTCACHE		(1 << 16)
 #define I_SYNC_QUEUED		(1 << 17)
-#define __I_LRU_ISOLATING	19
-#define I_LRU_ISOLATING		(1 << __I_LRU_ISOLATING)
 
 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)