NFSv4.1: Free the pnfs_layout_hdr outside the inode->i_lock

None of the existing pNFS layout drivers seem to require the inode
to be locked while they free the layout header.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 7ac5be3..0866314 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -213,7 +213,7 @@ pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 }
 
 static void
-destroy_layout_hdr(struct pnfs_layout_hdr *lo)
+pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 {
        struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
        dprintk("%s: freeing layout cache %p\n", __func__, lo);
@@ -222,14 +222,6 @@ destroy_layout_hdr(struct pnfs_layout_hdr *lo)
        /* Reset MDS Threshold I/O counters */
        nfsi->write_io = 0;
        nfsi->read_io = 0;
-       pnfs_free_layout_hdr(lo);
-}
-
-static void
-pnfs_put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
-{
-       if (atomic_dec_and_test(&lo->plh_refcount))
-               destroy_layout_hdr(lo);
 }
 
 void
@@ -238,8 +230,9 @@ pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
        struct inode *inode = lo->plh_inode;
 
        if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
-               destroy_layout_hdr(lo);
+               pnfs_detach_layout_hdr(lo);
                spin_unlock(&inode->i_lock);
+               pnfs_free_layout_hdr(lo);
        }
 }
 
@@ -792,8 +785,12 @@ void pnfs_roc_release(struct inode *ino)
        spin_lock(&ino->i_lock);
        lo = NFS_I(ino)->layout;
        lo->plh_block_lgets--;
-       pnfs_put_layout_hdr_locked(lo);
-       spin_unlock(&ino->i_lock);
+       if (atomic_dec_and_test(&lo->plh_refcount)) {
+               pnfs_detach_layout_hdr(lo);
+               spin_unlock(&ino->i_lock);
+               pnfs_free_layout_hdr(lo);
+       } else
+               spin_unlock(&ino->i_lock);
 }
 
 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)