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From:   Tetsuhiro Kohada <kohada.t2@gmail.com>
To:     kohada.t2@gmail.com
Cc:     kohada.tetsuhiro@dc.mitsubishielectric.co.jp,
        mori.takahiro@ab.mitsubishielectric.co.jp,
        motai.hirotaka@aj.mitsubishielectric.co.jp,
        Namjae Jeon <namjae.jeon@samsung.com>,
        Sungjong Seo <sj1557.seo@samsung.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] exfat: eliminate dead code in exfat_find()
Date:   Wed,  2 Sep 2020 16:53:06 +0900
Message-Id: <20200902075306.8439-1-kohada.t2@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The exfat_find_dir_entry() called by exfat_find() doesn't return -EEXIST.
Therefore, the root-dir information setting is never executed.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
---
 fs/exfat/dir.c   |   1 -
 fs/exfat/namei.c | 120 +++++++++++++++++++----------------------------
 2 files changed, 47 insertions(+), 74 deletions(-)

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 573659bfbc55..a9b13ae3f325 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -911,7 +911,6 @@ enum {
 /*
  * return values:
  *   >= 0	: return dir entiry position with the name in dir
- *   -EEXIST	: (root dir, ".") it is the root dir itself
  *   -ENOENT	: entry with the name does not exist
  *   -EIO	: I/O error
  */
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 0b12033e1577..b966b9120c9c 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -604,6 +604,8 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 	struct super_block *sb = dir->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(dir);
+	struct exfat_dentry *ep, *ep2;
+	struct exfat_entry_set_cache *es;
 
 	if (qname->len == 0)
 		return -ENOENT;
@@ -629,91 +631,63 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
 			num_entries, TYPE_ALL);
 
-	if ((dentry < 0) && (dentry != -EEXIST))
+	if (dentry < 0)
 		return dentry; /* -error value */
 
 	memcpy(&info->dir, &cdir.dir, sizeof(struct exfat_chain));
 	info->entry = dentry;
 	info->num_subdirs = 0;
 
-	/* root directory itself */
-	if (unlikely(dentry == -EEXIST)) {
-		int num_clu = 0;
+	es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
+	if (!es)
+		return -EIO;
+	ep = exfat_get_dentry_cached(es, 0);
+	ep2 = exfat_get_dentry_cached(es, 1);
+
+	info->type = exfat_get_entry_type(ep);
+	info->attr = le16_to_cpu(ep->dentry.file.attr);
+	info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
+	if ((info->type == TYPE_FILE) && (info->size == 0)) {
+		info->flags = ALLOC_NO_FAT_CHAIN;
+		info->start_clu = EXFAT_EOF_CLUSTER;
+	} else {
+		info->flags = ep2->dentry.stream.flags;
+		info->start_clu =
+			le32_to_cpu(ep2->dentry.stream.start_clu);
+	}
 
-		info->type = TYPE_DIR;
-		info->attr = ATTR_SUBDIR;
-		info->flags = ALLOC_FAT_CHAIN;
-		info->start_clu = sbi->root_dir;
-		memset(&info->crtime, 0, sizeof(info->crtime));
-		memset(&info->mtime, 0, sizeof(info->mtime));
-		memset(&info->atime, 0, sizeof(info->atime));
-
-		exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
-		if (exfat_count_num_clusters(sb, &cdir, &num_clu))
-			return -EIO;
-		info->size = num_clu << sbi->cluster_size_bits;
+	exfat_get_entry_time(sbi, &info->crtime,
+			     ep->dentry.file.create_tz,
+			     ep->dentry.file.create_time,
+			     ep->dentry.file.create_date,
+			     ep->dentry.file.create_time_cs);
+	exfat_get_entry_time(sbi, &info->mtime,
+			     ep->dentry.file.modify_tz,
+			     ep->dentry.file.modify_time,
+			     ep->dentry.file.modify_date,
+			     ep->dentry.file.modify_time_cs);
+	exfat_get_entry_time(sbi, &info->atime,
+			     ep->dentry.file.access_tz,
+			     ep->dentry.file.access_time,
+			     ep->dentry.file.access_date,
+			     0);
+	exfat_free_dentry_set(es, false);
+
+	if (ei->start_clu == EXFAT_FREE_CLUSTER) {
+		exfat_fs_error(sb,
+			       "non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
+			       i_size_read(dir), ei->dir.dir, ei->entry);
+		return -EIO;
+	}
 
+	if (info->type == TYPE_DIR) {
+		exfat_chain_set(&cdir, info->start_clu,
+				EXFAT_B_TO_CLU(info->size, sbi), info->flags);
 		count = exfat_count_dir_entries(sb, &cdir);
 		if (count < 0)
 			return -EIO;
 
-		info->num_subdirs = count;
-	} else {
-		struct exfat_dentry *ep, *ep2;
-		struct exfat_entry_set_cache *es;
-
-		es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
-		if (!es)
-			return -EIO;
-		ep = exfat_get_dentry_cached(es, 0);
-		ep2 = exfat_get_dentry_cached(es, 1);
-
-		info->type = exfat_get_entry_type(ep);
-		info->attr = le16_to_cpu(ep->dentry.file.attr);
-		info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
-		if ((info->type == TYPE_FILE) && (info->size == 0)) {
-			info->flags = ALLOC_NO_FAT_CHAIN;
-			info->start_clu = EXFAT_EOF_CLUSTER;
-		} else {
-			info->flags = ep2->dentry.stream.flags;
-			info->start_clu =
-				le32_to_cpu(ep2->dentry.stream.start_clu);
-		}
-
-		if (ei->start_clu == EXFAT_FREE_CLUSTER) {
-			exfat_fs_error(sb,
-				"non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
-				i_size_read(dir), ei->dir.dir, ei->entry);
-			exfat_free_dentry_set(es, false);
-			return -EIO;
-		}
-
-		exfat_get_entry_time(sbi, &info->crtime,
-				ep->dentry.file.create_tz,
-				ep->dentry.file.create_time,
-				ep->dentry.file.create_date,
-				ep->dentry.file.create_time_cs);
-		exfat_get_entry_time(sbi, &info->mtime,
-				ep->dentry.file.modify_tz,
-				ep->dentry.file.modify_time,
-				ep->dentry.file.modify_date,
-				ep->dentry.file.modify_time_cs);
-		exfat_get_entry_time(sbi, &info->atime,
-				ep->dentry.file.access_tz,
-				ep->dentry.file.access_time,
-				ep->dentry.file.access_date,
-				0);
-		exfat_free_dentry_set(es, false);
-
-		if (info->type == TYPE_DIR) {
-			exfat_chain_set(&cdir, info->start_clu,
-				EXFAT_B_TO_CLU(info->size, sbi), info->flags);
-			count = exfat_count_dir_entries(sb, &cdir);
-			if (count < 0)
-				return -EIO;
-
-			info->num_subdirs = count + EXFAT_MIN_SUBDIR;
-		}
+		info->num_subdirs = count + EXFAT_MIN_SUBDIR;
 	}
 	return 0;
 }
-- 
2.25.1