From 9c0e3a7b4e97d30844ab8efbadd9ad7e9fefc82b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Pierre=20Andr=C3=A9?= <jpandre@users.sourceforge.net>
Date: Tue, 26 Oct 2010 08:59:51 +0200
Subject: [PATCH] Enabled use of fuse cacheing in lowntfs-3g under conditions

---
 include/ntfs-3g/param.h |  9 +++++++--
 src/lowntfs-3g.c        | 36 ++++++++++++++++++++++++++++++------
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/include/ntfs-3g/param.h b/include/ntfs-3g/param.h
index f21bd653..9edb9642 100644
--- a/include/ntfs-3g/param.h
+++ b/include/ntfs-3g/param.h
@@ -58,7 +58,8 @@ enum {
  *
  *	Stick to the recommended values unless you understand the consequences
  *	on protection and performances. Use of cacheing is good for
- *	performances, but bad on security.
+ *	performances, but bad on security with internal fuse or external
+ *	fuse older than 2.8
  *
  *	Possible values for high level :
  *		1 : no cache, kernel control (recommended)
@@ -67,7 +68,7 @@ enum {
  *
  *	Possible values for low level :
  *		2 : no cache, kernel control
- *		3 : use kernel/fuse cache, kernel control
+ *		3 : use kernel/fuse cache, kernel control (external fuse >= 2.8)
  *		5 : no cache, file system control (recommended)
  *		8 : no cache, kernel control for ACLs
  *
@@ -77,6 +78,10 @@ enum {
  */
 
 #define HPERMSCONFIG 1
+#if defined(FUSE_INTERNAL) || !defined(FUSE_VERSION) || (FUSE_VERSION < 28)
 #define LPERMSCONFIG 5
+#else
+#define LPERMSCONFIG 3
+#endif
 
 #endif /* defined _NTFS_PARAM_H */
diff --git a/src/lowntfs-3g.c b/src/lowntfs-3g.c
index 17105c73..6c580421 100644
--- a/src/lowntfs-3g.c
+++ b/src/lowntfs-3g.c
@@ -122,18 +122,17 @@
 #endif
 
 #if CACHEING & (KERNELACLS | !KERNELPERMS)
-#warning "Fuse cacheing is broken unless basic permissions checked by kernel"
+#warning "Fuse cacheing is only usable with basic permissions checked by kernel"
 #endif
 
 #if !CACHEING
-	/*
-	 * FUSE cacheing is broken except for basic permissions
-	 * checked by the kernel
-	 * So do not use cacheing until this is fixed
-	 */
 #define ATTR_TIMEOUT 0.0
 #define ENTRY_TIMEOUT 0.0
 #else
+	/*
+	 * FUSE cacheing is only usable with basic permissions
+	 * checked by the kernel with external fuse >= 2.8
+	 */
 #define ATTR_TIMEOUT (ctx->vol->secure_flags & (1 << SECURITY_DEFAULT) ? 1.0 : 0.0)
 #define ENTRY_TIMEOUT (ctx->vol->secure_flags & (1 << SECURITY_DEFAULT) ? 1.0 : 0.0)
 #endif
@@ -3028,6 +3027,18 @@ static void ntfs_fuse_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
 				set_fuse_error(&res);
 		} else
 			res = -errno;
+#endif
+#if CACHEING && !defined(FUSE_INTERNAL)
+		/*
+		 * Most of system xattr settings cause changes to some
+		 * file attribute (st_mode, st_nlink, st_mtime, etc.),
+		 * so we must invalidate cached data when cacheing is
+		 * in use (not possible with internal fuse or external
+		 * fuse before 2.8)
+		 */
+		if ((res >= 0)
+		    && fuse_lowlevel_notify_inval_inode(ctx->fc, ino, -1, 0))
+			res = -errno;
 #endif
 		if (res < 0)
 			fuse_reply_err(req, -res);
@@ -3231,6 +3242,19 @@ static void ntfs_fuse_removexattr(fuse_req_t req, fuse_ino_t ino, const char *na
 					set_fuse_error(&res);
 			} else
 				res = -errno;
+#endif
+#if CACHEING && !defined(FUSE_INTERNAL)
+		/*
+		 * Some allowed system xattr removals cause changes to
+		 * some file attribute (st_mode, st_nlink, etc.),
+		 * so we must invalidate cached data when cacheing is
+		 * in use (not possible with internal fuse or external
+		 * fuse before 2.8)
+		 */
+			if ((res >= 0)
+			    && fuse_lowlevel_notify_inval_inode(ctx->fc,
+						ino, -1, 0))
+				res = -errno;
 #endif
 			break;
 		}