[AFS]: Add "directory write" support.

Add support for the create, link, symlink, unlink, mkdir, rmdir and
rename VFS operations to the in-kernel AFS filesystem.

Also:

 (1) Fix dentry and inode revalidation.  d_revalidate should only look at
     state of the dentry.  Revalidation of the contents of an inode pointed to
     by a dentry is now separate.

 (2) Fix afs_lookup() to hash negative dentries as well as positive ones.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 105 insertions, 10 deletions

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 22733622829..56ca8581b37 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -33,7 +33,7 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 {
         struct inode *inode = AFS_VNODE_TO_I(vnode);
 
-        _debug("FS: ft=%d lk=%d sz=%Zu ver=%Lu mod=%hu",
+        _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
                vnode->status.type,
                vnode->status.nlink,
                vnode->status.size,
@@ -115,8 +115,9 @@ static int afs_iget5_set(struct inode *inode, void *opaque)
 /*
  * inode retrieval
  */
-inline struct inode *afs_iget(struct super_block *sb, struct key *key,
-                              struct afs_fid *fid)
+struct inode *afs_iget(struct super_block *sb, struct key *key,
+                       struct afs_fid *fid, struct afs_file_status *status,
+                       struct afs_callback *cb)
 {
         struct afs_iget_data data = { .fid = *fid };
         struct afs_super_info *as;
@@ -156,16 +157,37 @@ inline struct inode *afs_iget(struct super_block *sb, struct key *key,
                                &vnode->cache);
 #endif
 
-        /* okay... it's a new inode */
-        set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
-        ret = afs_vnode_fetch_status(vnode, NULL, key);
-        if (ret < 0)
-                goto bad_inode;
+        if (!status) {
+                /* it's a remotely extant inode */
+                set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
+                ret = afs_vnode_fetch_status(vnode, NULL, key);
+                if (ret < 0)
+                        goto bad_inode;
+        } else {
+                /* it's an inode we just created */
+                memcpy(&vnode->status, status, sizeof(vnode->status));
+
+                if (!cb) {
+                        /* it's a symlink we just created (the fileserver
+                         * didn't give us a callback) */
+                        vnode->cb_version = 0;
+                        vnode->cb_expiry = 0;
+                        vnode->cb_type = 0;
+                        vnode->cb_expires = get_seconds();
+                } else {
+                        vnode->cb_version = cb->version;
+                        vnode->cb_expiry = cb->expiry;
+                        vnode->cb_type = cb->type;
+                        vnode->cb_expires = vnode->cb_expiry + get_seconds();
+                }
+        }
+
         ret = afs_inode_map_status(vnode, key);
         if (ret < 0)
                 goto bad_inode;
 
         /* success */
+        clear_bit(AFS_VNODE_UNSET, &vnode->flags);
         inode->i_flags |= S_NOATIME;
         unlock_new_inode(inode);
         _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
@@ -182,6 +204,78 @@ bad_inode:
 }
 
 /*
+ * validate a vnode/inode
+ * - there are several things we need to check
+ *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
+ *     symlink)
+ *   - parent dir metadata changed (security changes)
+ *   - dentry data changed (write, truncate)
+ *   - dentry metadata changed (security changes)
+ */
+int afs_validate(struct afs_vnode *vnode, struct key *key)
+{
+        int ret;
+
+        _enter("{v={%x:%u} fl=%lx},%x",
+               vnode->fid.vid, vnode->fid.vnode, vnode->flags,
+               key_serial(key));
+
+        if (vnode->cb_promised &&
+            !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
+            !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
+            !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
+                if (vnode->cb_expires < get_seconds() + 10) {
+                        _debug("callback expired");
+                        set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
+                } else {
+                        goto valid;
+                }
+        }
+
+        if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
+                goto valid;
+
+        mutex_lock(&vnode->validate_lock);
+
+        /* if the promise has expired, we need to check the server again to get
+         * a new promise - note that if the (parent) directory's metadata was
+         * changed then the security may be different and we may no longer have
+         * access */
+        if (!vnode->cb_promised ||
+            test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
+                _debug("not promised");
+                ret = afs_vnode_fetch_status(vnode, NULL, key);
+                if (ret < 0)
+                        goto error_unlock;
+                _debug("new promise [fl=%lx]", vnode->flags);
+        }
+
+        if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
+                _debug("file already deleted");
+                ret = -ESTALE;
+                goto error_unlock;
+        }
+
+        /* if the vnode's data version number changed then its contents are
+         * different */
+        if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
+                _debug("zap data {%x:%d}", vnode->fid.vid, vnode->fid.vnode);
+                invalidate_remote_inode(&vnode->vfs_inode);
+        }
+
+        clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
+        mutex_unlock(&vnode->validate_lock);
+valid:
+        _leave(" = 0");
+        return 0;
+
+error_unlock:
+        mutex_unlock(&vnode->validate_lock);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
  * read the attributes of an inode
  */
 int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
@@ -207,9 +301,10 @@ void afs_clear_inode(struct inode *inode)
 
         vnode = AFS_FS_I(inode);
 
-        _enter("ino=%lu { vn=%08x v=%u x=%u t=%u }",
-               inode->i_ino,
+        _enter("{%x:%d.%d} v=%u x=%u t=%u }",
+               vnode->fid.vid,
                vnode->fid.vnode,
+               vnode->fid.unique,
                vnode->cb_version,
                vnode->cb_expiry,
                vnode->cb_type);