From: Eric Biggers <ebiggers3@gmail.com>
Date: Sun, 31 May 2015 15:43:49 +0000 (-0500)
Subject: ntfs-3g_apply.c: Do not use i_visited
X-Git-Tag: v1.8.2~78
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=26a90546f2a8ded51376d631e5a13f3d7a84f8dc

ntfs-3g_apply.c: Do not use i_visited

The number of inodes examined is limited by MAX_OPEN_FILES, and we can
make it faster in the common case by checking i_num_streams.
---

diff --git a/include/wimlib/inode.h b/include/wimlib/inode.h
index 07d1885f..2fd9f083 100644
--- a/include/wimlib/inode.h
+++ b/include/wimlib/inode.h
@@ -129,10 +129,8 @@ struct wim_inode {
 	/* Number of dentries that are aliases for this inode.  */
 	u32 i_nlink : 30;
 
-	/* Flag used to mark this inode as visited; this is used when visiting
-	 * all the inodes in a dentry tree exactly once.  It will be 0 by
-	 * default and must be cleared following the tree traversal, even in
-	 * error paths.  */
+	/* Flag used by some code to mark this inode as visited.  It will be 0
+	 * by default, and it always must be cleared after use.  */
 	u32 i_visited : 1;
 
 	/* Cached value  */
diff --git a/src/ntfs-3g_apply.c b/src/ntfs-3g_apply.c
index 3dcf8d53..8f077467 100644
--- a/src/ntfs-3g_apply.c
+++ b/src/ntfs-3g_apply.c
@@ -760,28 +760,29 @@ ntfs_3g_cleanup_blob_extract(struct ntfs_3g_apply_ctx *ctx)
 static ntfs_inode *
 ntfs_3g_open_inode(struct wim_inode *inode, struct ntfs_3g_apply_ctx *ctx)
 {
-	ntfs_inode *ni = NULL;
+	ntfs_inode *ni;
 
-	if (inode->i_visited) {
-		for (u32 i = 0; i < ctx->num_open_inodes; i++) {
+	/* If the same blob is being extracted to multiple streams of the same
+	 * inode, then we must only open the inode once.  */
+	if (unlikely(inode->i_num_streams > 1)) {
+		for (unsigned i = 0; i < ctx->num_open_inodes; i++) {
 			if (ctx->open_inodes[i]->mft_no == inode->i_mft_no) {
 				ni = ctx->open_inodes[i];
-				break;
+				goto have_inode;
 			}
 		}
 	}
-	if (!ni) {
-		ni = ntfs_inode_open(ctx->vol, inode->i_mft_no);
-		ctx->open_inodes[ctx->num_open_inodes++] = ni;
-		inode->i_visited = 1;
-	}
 
-	if (!ni) {
+	ni = ntfs_inode_open(ctx->vol, inode->i_mft_no);
+	if (unlikely(!ni)) {
 		ERROR_WITH_ERRNO("Can't open \"%s\" in NTFS volume",
 				 dentry_full_path(
 					inode_first_extraction_dentry(inode)));
 		return NULL;
 	}
+
+have_inode:
+	ctx->open_inodes[ctx->num_open_inodes++] = ni;
 	return ni;
 }
 
@@ -811,8 +812,6 @@ ntfs_3g_begin_extract_blob(struct blob_descriptor *blob, void *_ctx)
 out_cleanup:
 	ntfs_3g_cleanup_blob_extract(ctx);
 out:
-	for (u32 i = 0; i < blob->out_refcnt; i++)
-		targets[i].inode->i_visited = 0;
 	return ret;
 }