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: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 1c71fc2..ee9a179 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1716,22 +1716,14 @@
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 @@
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);
