1 files changed, 113 insertions, 22 deletions

diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 7503899c0a1b..d7d9402ff718 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -10,6 +10,100 @@
 #include <linux/dns_resolver.h>
 #include "internal.h"
 
+static atomic_t afs_autocell_ino;
+
+/*
+ * iget5() comparator for inode created by autocell operations
+ *
+ * These pseudo inodes don't match anything.
+ */
+static int afs_iget5_pseudo_test(struct inode *inode, void *opaque)
+{
+	return 0;
+}
+
+/*
+ * iget5() inode initialiser
+ */
+static int afs_iget5_pseudo_set(struct inode *inode, void *opaque)
+{
+	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
+	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct afs_fid *fid = opaque;
+
+	vnode->volume		= as->volume;
+	vnode->fid		= *fid;
+	inode->i_ino		= fid->vnode;
+	inode->i_generation	= fid->unique;
+	return 0;
+}
+
+/*
+ * Create an inode for a dynamic root directory or an autocell dynamic
+ * automount dir.
+ */
+struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
+{
+	struct afs_super_info *as = AFS_FS_S(sb);
+	struct afs_vnode *vnode;
+	struct inode *inode;
+	struct afs_fid fid = {};
+
+	_enter("");
+
+	if (as->volume)
+		fid.vid = as->volume->vid;
+	if (root) {
+		fid.vnode = 1;
+		fid.unique = 1;
+	} else {
+		fid.vnode = atomic_inc_return(&afs_autocell_ino);
+		fid.unique = 0;
+	}
+
+	inode = iget5_locked(sb, fid.vnode,
+			     afs_iget5_pseudo_test, afs_iget5_pseudo_set, &fid);
+	if (!inode) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	_debug("GOT INODE %p { ino=%lu, vl=%llx, vn=%llx, u=%x }",
+	       inode, inode->i_ino, fid.vid, fid.vnode, fid.unique);
+
+	vnode = AFS_FS_I(inode);
+
+	/* there shouldn't be an existing inode */
+	BUG_ON(!(inode->i_state & I_NEW));
+
+	netfs_inode_init(&vnode->netfs, NULL);
+	inode->i_size		= 0;
+	inode->i_mode		= S_IFDIR | S_IRUGO | S_IXUGO;
+	if (root) {
+		inode->i_op	= &afs_dynroot_inode_operations;
+		inode->i_fop	= &simple_dir_operations;
+	} else {
+		inode->i_op	= &afs_autocell_inode_operations;
+	}
+	set_nlink(inode, 2);
+	inode->i_uid		= GLOBAL_ROOT_UID;
+	inode->i_gid		= GLOBAL_ROOT_GID;
+	inode->i_ctime = inode->i_atime = inode->i_mtime = current_time(inode);
+	inode->i_blocks		= 0;
+	inode->i_generation	= 0;
+
+	set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
+	if (!root) {
+		set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+		inode->i_flags |= S_AUTOMOUNT;
+	}
+
+	inode->i_flags |= S_NOATIME;
+	unlock_new_inode(inode);
+	_leave(" = %p", inode);
+	return inode;
+}
+
 /*
  * Probe to see if a cell may exist.  This prevents positive dentries from
  * being created unnecessarily.
@@ -30,9 +124,9 @@ static int afs_probe_cell_name(struct dentry *dentry)
 		len--;
 	}
 
-	cell = afs_lookup_cell_rcu(net, name, len);
+	cell = afs_find_cell(net, name, len, afs_cell_trace_use_probe);
 	if (!IS_ERR(cell)) {
-		afs_put_cell(net, cell);
+		afs_unuse_cell(net, cell, afs_cell_trace_unuse_probe);
 		return 0;
 	}
 
@@ -86,7 +180,6 @@ static struct dentry *afs_lookup_atcell(struct dentry *dentry)
 	struct afs_cell *cell;
 	struct afs_net *net = afs_d2net(dentry);
 	struct dentry *ret;
-	unsigned int seq = 0;
 	char *name;
 	int len;
 
@@ -98,17 +191,13 @@ static struct dentry *afs_lookup_atcell(struct dentry *dentry)
 	if (!name)
 		goto out_p;
 
-	rcu_read_lock();
-	do {
-		read_seqbegin_or_lock(&net->cells_lock, &seq);
-		cell = rcu_dereference_raw(net->ws_cell);
-		if (cell) {
-			len = cell->name_len;
-			memcpy(name, cell->name, len + 1);
-		}
-	} while (need_seqretry(&net->cells_lock, seq));
-	done_seqretry(&net->cells_lock, seq);
-	rcu_read_unlock();
+	down_read(&net->cells_lock);
+	cell = net->ws_cell;
+	if (cell) {
+		len = cell->name_len;
+		memcpy(name, cell->name, len + 1);
+	}
+	up_read(&net->cells_lock);
 
 	ret = ERR_PTR(-ENOENT);
 	if (!cell)
@@ -289,15 +378,17 @@ void afs_dynroot_depopulate(struct super_block *sb)
 		net->dynroot_sb = NULL;
 	mutex_unlock(&net->proc_cells_lock);
 
-	inode_lock(root->d_inode);
+	if (root) {
+		inode_lock(root->d_inode);
 
-	/* Remove all the pins for dirs created for manually added cells */
-	list_for_each_entry_safe(subdir, tmp, &root->d_subdirs, d_child) {
-		if (subdir->d_fsdata) {
-			subdir->d_fsdata = NULL;
-			dput(subdir);
+		/* Remove all the pins for dirs created for manually added cells */
+		list_for_each_entry_safe(subdir, tmp, &root->d_subdirs, d_child) {
+			if (subdir->d_fsdata) {
+				subdir->d_fsdata = NULL;
+				dput(subdir);
+			}
 		}
-	}
 
-	inode_unlock(root->d_inode);
+		inode_unlock(root->d_inode);
+	}
 }