1 files changed, 142 insertions, 0 deletions

diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
index 17fa3ff7b..e5371dacd 100644
--- a/include/linux/vfs_compat.h
+++ b/include/linux/vfs_compat.h
@@ -174,4 +174,146 @@ lseek_execute(struct file *filp, struct inode *inode,
 }
 #endif /* SEEK_HOLE && SEEK_DATA && !HAVE_LSEEK_EXECUTE */
 
+/*
+ * These functions safely approximates the behavior of posix_acl_release()
+ * which cannot be used because it calls the GPL-only symbol kfree_rcu().
+ * The in-kernel version, which can access the RCU, frees the ACLs after
+ * the grace period expires.  Because we're unsure how long that grace
+ * period may be this implementation conservatively delays for 60 seconds.
+ * This is several orders of magnitude larger than expected grace period.
+ * At 60 seconds the kernel will also begin issuing RCU stall warnings.
+ */
+#include <linux/posix_acl.h>
+#ifndef HAVE_POSIX_ACL_CACHING
+#define ACL_NOT_CACHED ((void *)(-1))
+#endif /* HAVE_POSIX_ACL_CACHING */
+
+#if defined(HAVE_POSIX_ACL_RELEASE) && !defined(HAVE_POSIX_ACL_RELEASE_GPL_ONLY)
+
+#define	zpl_posix_acl_release(arg)		posix_acl_release(arg)
+#define	zpl_set_cached_acl(ip, ty, n)		set_cached_acl(ip, ty, n)
+#define	zpl_forget_cached_acl(ip, ty)		forget_cached_acl(ip, ty)
+
+#else
+
+static inline void
+zpl_posix_acl_free(void *arg) {
+	kfree(arg);
+}
+
+static inline void
+zpl_posix_acl_release(struct posix_acl *acl)
+{
+	if ((acl == NULL) || (acl == ACL_NOT_CACHED))
+		return;
+
+	if (atomic_dec_and_test(&acl->a_refcount)) {
+		taskq_dispatch_delay(system_taskq, zpl_posix_acl_free, acl,
+		    TQ_SLEEP, ddi_get_lbolt() + 60*HZ);
+	}
+}
+
+static inline void
+zpl_set_cached_acl(struct inode *ip, int type, struct posix_acl *newer) {
+#ifdef HAVE_POSIX_ACL_CACHING
+	struct posix_acl *older = NULL;
+
+	spin_lock(&ip->i_lock);
+
+	if ((newer != ACL_NOT_CACHED) && (newer != NULL))
+		posix_acl_dup(newer);
+
+	switch(type) {
+	case ACL_TYPE_ACCESS:
+		older = ip->i_acl;
+		rcu_assign_pointer(ip->i_acl,newer);
+		break;
+	case ACL_TYPE_DEFAULT:
+		older = ip->i_default_acl;
+		rcu_assign_pointer(ip->i_default_acl,newer);
+		break;
+	}
+
+	spin_unlock(&ip->i_lock);
+
+	zpl_posix_acl_release(older);
+#endif /* HAVE_POSIX_ACL_CACHING */
+}
+
+static inline void
+zpl_forget_cached_acl(struct inode *ip, int type) {
+	zpl_set_cached_acl(ip, type, (struct posix_acl *)ACL_NOT_CACHED);
+}
+#endif /* HAVE_POSIX_ACL_RELEASE */
+
+/*
+ * 2.6.38 API change,
+ * The is_owner_or_cap() function was renamed to inode_owner_or_capable().
+ */
+#ifdef HAVE_INODE_OWNER_OR_CAPABLE
+#define	zpl_inode_owner_or_capable(ip)		inode_owner_or_capable(ip)
+#else
+#define	zpl_inode_owner_or_capable(ip)		is_owner_or_cap(ip)
+#endif /* HAVE_INODE_OWNER_OR_CAPABLE */
+
+#ifndef HAVE_POSIX_ACL_CHMOD
+static inline int
+posix_acl_chmod(struct posix_acl **acl, int flags, umode_t umode) {
+	struct posix_acl *oldacl = *acl;
+	mode_t mode = umode;
+	int error;
+
+	*acl = posix_acl_clone(*acl, flags);
+	zpl_posix_acl_release(oldacl);
+
+	if (!(*acl))
+		return (-ENOMEM);
+
+	error = posix_acl_chmod_masq(*acl, mode);
+	if (error) {
+		zpl_posix_acl_release(*acl);
+		*acl = NULL;
+	}
+
+        return (error);
+}
+
+static inline int
+posix_acl_create(struct posix_acl** acl, int flags, umode_t* umodep) {
+	struct posix_acl *oldacl = *acl;
+	mode_t mode = *umodep;
+	int error;
+
+	*acl = posix_acl_clone(*acl, flags);
+	zpl_posix_acl_release(oldacl);
+
+	if (!(*acl))
+		return (-ENOMEM);
+
+	error = posix_acl_create_masq(*acl, &mode);
+	*umodep = mode;
+
+	if (error < 0) {
+		zpl_posix_acl_release(*acl);
+		*acl = NULL;
+	}
+
+	return (error);
+}
+#endif /* HAVE_POSIX_ACL_CHMOD */
+
+#ifndef HAVE_CURRENT_UMASK
+static inline int
+current_umask(void)
+{
+	return (current->fs->umask);
+}
+#endif /* HAVE_CURRENT_UMASK */
+
+#ifdef HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T
+typedef umode_t zpl_equivmode_t;
+#else
+typedef mode_t zpl_equivmode_t;
+#endif /* HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T */
+
 #endif /* _ZFS_VFS_H */