afs: Fix unlink to handle YFS.RemoveFile2 better

Make use of the status update for the target file that the YFS.RemoveFile2
RPC op returns to correctly update the vnode as to whether the file was
actually deleted or just had nlink reduced.

Fixes: 30062bd13e36 ("afs: Implement YFS support in the fs client")
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 13 insertions, 23 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 338c2260b0a0..d1b3736a3bbd 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -1299,32 +1299,27 @@ error:
  * However, if we didn't have a callback promise outstanding, or it was
  * outstanding on a different server, then it won't break it either...
  */
-int afs_dir_remove_link(struct dentry *dentry, struct key *key,
-			unsigned long d_version_before,
-			unsigned long d_version_after)
+static int afs_dir_remove_link(struct afs_vnode *dvnode, struct dentry *dentry,
+			       struct key *key)
 {
-	bool dir_valid;
 	int ret = 0;
 
-	/* There were no intervening changes on the server if the version
-	 * number we got back was incremented by exactly 1.
-	 */
-	dir_valid = (d_version_after == d_version_before + 1);
-
 	if (d_really_is_positive(dentry)) {
 		struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 
 		if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 			/* Already done */
-		} else if (dir_valid) {
+		} else if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
+			write_seqlock(&vnode->cb_lock);
 			drop_nlink(&vnode->vfs_inode);
 			if (vnode->vfs_inode.i_nlink == 0) {
 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
-				clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+				__afs_break_callback(vnode);
 			}
+			write_sequnlock(&vnode->cb_lock);
 			ret = 0;
 		} else {
-			clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+			afs_break_callback(vnode);
 
 			if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 				kdebug("AFS_VNODE_DELETED");
@@ -1348,7 +1343,6 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
 	struct afs_status_cb *scb;
 	struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode = NULL;
 	struct key *key;
-	unsigned long d_version = (unsigned long)dentry->d_fsdata;
 	bool need_rehash = false;
 	int ret;
 
@@ -1395,20 +1389,16 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
 	ret = -ERESTARTSYS;
 	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		afs_dataversion_t data_version = dvnode->status.data_version + 1;
+		afs_dataversion_t data_version_2 = vnode->status.data_version;
 
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
+			fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
 
 			if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
 			    !test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
 				yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
 						    &scb[0], &scb[1]);
-				if (fc.ac.error == 0 &&
-				    scb[1].status.abort_code == VNOVNODE) {
-					set_bit(AFS_VNODE_DELETED, &vnode->flags);
-					afs_break_callback(vnode);
-				}
-
 				if (fc.ac.error != -ECONNABORTED ||
 				    fc.ac.abort_code != RXGEN_OPCODE)
 					continue;
@@ -1420,11 +1410,11 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
 
 		afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
 					&data_version, &scb[0]);
+		afs_vnode_commit_status(&fc, vnode, fc.cb_break_2,
+					&data_version_2, &scb[1]);
 		ret = afs_end_vnode_operation(&fc);
-		if (ret == 0)
-			ret = afs_dir_remove_link(
-				dentry, key, d_version,
-				(unsigned long)dvnode->status.data_version);
+		if (ret == 0 && !(scb[1].have_status || scb[1].have_error))
+			ret = afs_dir_remove_link(dvnode, dentry, key);
 		if (ret == 0 &&
 		    test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
 			afs_edit_dir_remove(dvnode, &dentry->d_name,