From 9630c075409a262424805411ed473178814b412c Mon Sep 17 00:00:00 2001
From: Michael Meffie <mmeffie@sinenomine.net>
Date: Sun, 18 May 2014 17:17:38 -0400
Subject: [PATCH] libafs: api to create and free vattrs

Add a pair of functions to allocate and free struct vattrs,
to avoid having struct vattrs on the stack.

Change-Id: Ia5a148ebcdf8a2f1e3a2aa9d8fd3c0e0cd0e25e9
Reviewed-on: http://gerrit.openafs.org/11169
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: D Brashear <shadow@your-file-system.com>
---
 src/afs/VNOPS/afs_vnop_attrs.c | 48 ++++++++++++++++++++++++++++++++++++++++++
 src/afs/afs_prototypes.h       |  2 ++
 2 files changed, 50 insertions(+)

diff --git a/src/afs/VNOPS/afs_vnop_attrs.c b/src/afs/VNOPS/afs_vnop_attrs.c
index 64797c2..798e2c1 100644
--- a/src/afs/VNOPS/afs_vnop_attrs.c
+++ b/src/afs/VNOPS/afs_vnop_attrs.c
@@ -17,6 +17,8 @@
  * afs_getattr
  * afs_VAttrToAS
  * afs_setattr
+ * afs_CreateAttr
+ * afs_DestroyAttr
  *
  */
 
@@ -654,3 +656,49 @@ afs_setattr(OSI_VC_DECL(avc), struct vattr *attrs,
     afs_DestroyReq(treq);
     return code;
 }
+
+/*!
+ * Allocate a vattr.
+ *
+ * \note The caller must free the allocated vattr with
+ *       afs_DestroyAttr() if this function returns successfully (zero).
+ *
+ * \note The GLOCK must be held on platforms which require the GLOCK
+ *       for osi_AllocSmallSpace() and osi_FreeSmallSpace().
+ *
+ * \param[out] out   address of the vattr pointer
+ * \return     0 on success
+ */
+int
+afs_CreateAttr(struct vattr **out)
+{
+    struct vattr *vattr = NULL;
+
+    if (!out) {
+	return EINVAL;
+    }
+    vattr = osi_AllocSmallSpace(sizeof(struct vattr));
+    if (!vattr) {
+	return ENOMEM;
+    }
+    memset(vattr, 0, sizeof(struct vattr));
+    *out = vattr;
+    return 0;
+}
+
+/*!
+ * Deallocate a vattr.
+ *
+ * \note The GLOCK must be held on platforms which require the GLOCK
+ *       for osi_FreeSmallSpace().
+ *
+ * \param[in]  vattr  pointer to the vattr to free; may be NULL
+ */
+void
+afs_DestroyAttr(struct vattr *vattr)
+{
+    if (vattr) {
+	osi_FreeSmallSpace(vattr);
+    }
+}
+
diff --git a/src/afs/afs_prototypes.h b/src/afs/afs_prototypes.h
index df056b0..6a1db16 100644
--- a/src/afs/afs_prototypes.h
+++ b/src/afs/afs_prototypes.h
@@ -1171,6 +1171,8 @@ extern int afs_setattr(OSI_VC_DECL(avc), struct vattr *attrs,
 extern int afs_setattr(OSI_VC_DECL(avc), struct vattr *attrs,
 		       afs_ucred_t *acred);
 #endif
+extern int afs_CreateAttr(struct vattr **out);
+extern void afs_DestroyAttr(struct vattr *vattr);
 
 /* VNOPS/afs_vnop_create.c */
 #ifdef AFS_SGI64_ENV
-- 
1.9.4