Commit 9c7e7e23 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Don't call iput() in nfs_access_cache_shrinker 



iput() can potentially attempt to allocate memory, so we should avoid
calling it in a memory shrinker. Instead, rely on the fact that iput() will
call nfs_access_zap_cache().

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 1a81bb8a

fs/nfs/dir.c

+4 −15
Original line number Diff line number Diff line
@@ -1716,22 +1716,14 @@ int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) 


	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)

		return (nr_to_scan == 0) ? 0 : -1;

restart:



	spin_lock(&nfs_access_lru_lock);

	list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) {

		struct rw_semaphore *s_umount;

		struct inode *inode;



		if (nr_to_scan-- == 0)

			break;

		s_umount = &nfsi->vfs_inode.i_sb->s_umount;

		if (!down_read_trylock(s_umount))

			continue;

		inode = igrab(&nfsi->vfs_inode);

		if (inode == NULL) {

			up_read(s_umount);

			continue;

		}

		inode = &nfsi->vfs_inode;

		spin_lock(&inode->i_lock);

		if (list_empty(&nfsi->access_cache_entry_lru))

			goto remove_lru_entry;
@@ -1745,13 +1737,10 @@ int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) 
		else {

remove_lru_entry:

			list_del_init(&nfsi->access_cache_inode_lru);

			smp_mb__before_clear_bit();

			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);

			smp_mb__after_clear_bit();

		}

		spin_unlock(&inode->i_lock);

		spin_unlock(&nfs_access_lru_lock);

		iput(inode);

		up_read(s_umount);

		goto restart;

	}

	spin_unlock(&nfs_access_lru_lock);

	nfs_access_free_list(&head);