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Subject: [PATCH 53/67] afs: Invoke fscache_resize_cookie() when handling
 ATTR_SIZE for setattr
From:   David Howells <dhowells@redhat.com>
To:     linux-cachefs@redhat.com
Cc:     Marc Dionne <marc.dionne@auristor.com>,
        linux-afs@lists.infradead.org, dhowells@redhat.com,
        Trond Myklebust <trondmy@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        Steve French <sfrench@samba.org>,
        Dominique Martinet <asmadeus@codewreck.org>,
        Jeff Layton <jlayton@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Omar Sandoval <osandov@osandov.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org,
        linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
        v9fs-developer@lists.sourceforge.net,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Mon, 18 Oct 2021 16:04:08 +0100
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Invoke fscache_resize_cookie() to adjust the size of the backing cache
object when setattr is called with ATTR_SIZE.  This discards any data that
then lies beyond the revised EOF and frees up space.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
---

 fs/afs/inode.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 311df66c64d0..c4af4fda37dd 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -829,6 +829,9 @@ static void afs_setattr_edit_file(struct afs_operation *op)
 
 		if (size < i_size)
 			truncate_pagecache(inode, size);
+		if (size != i_size)
+			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
+					      vp->scb.status.size);
 	}
 }
 
@@ -872,6 +875,8 @@ int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 			attr->ia_valid &= ~ATTR_SIZE;
 	}
 
+	fscache_use_cookie(afs_vnode_cache(vnode), true);
+
 	/* flush any dirty data outstanding on a regular file */
 	if (S_ISREG(vnode->vfs_inode.i_mode))
 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
@@ -903,6 +908,7 @@ int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 
 out_unlock:
 	up_write(&vnode->validate_lock);
+	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
 	_leave(" = %d", ret);
 	return ret;
 }