exfat: add __exfat_get_dentry_set() helper

Since exfat_get_dentry_set() invokes the validate functions of
exfat_validate_entry(), it only supports getting a directory
entry set of an existing file, doesn't support getting an empty
entry set.

To remove the limitation, add this helper.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 9f9295847a4e6ecfd02fe3662b82e9f80479ada8..543b01a5479e9042a33aa2ed7c11f6af4065ea15 100644 (file)
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -775,7 +775,6 @@ struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
 }
 
 enum exfat_validate_dentry_mode {
-       ES_MODE_STARTED,
        ES_MODE_GET_FILE_ENTRY,
        ES_MODE_GET_STRM_ENTRY,
        ES_MODE_GET_NAME_ENTRY,
@@ -790,11 +789,6 @@ static bool exfat_validate_entry(unsigned int type,
                return false;
 
        switch (*mode) {
-       case ES_MODE_STARTED:
-               if  (type != TYPE_FILE && type != TYPE_DIR)
-                       return false;
-               *mode = ES_MODE_GET_FILE_ENTRY;
-               break;
        case ES_MODE_GET_FILE_ENTRY:
                if (type != TYPE_STREAM)
                        return false;
@@ -834,7 +828,7 @@ struct exfat_dentry *exfat_get_dentry_cached(
 }
 
 /*
- * Returns a set of dentries for a file or dir.
+ * Returns a set of dentries.
  *
  * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().
  * User should call exfat_get_dentry_set() after setting 'modified' to apply
@@ -842,22 +836,24 @@ struct exfat_dentry *exfat_get_dentry_cached(
  *
  * in:
  *   sb+p_dir+entry: indicates a file/dir
- *   type:  specifies how many dentries should be included.
+ *   num_entries: specifies how many dentries should be included.
+ *                It will be set to es->num_entries if it is not 0.
+ *                If num_entries is 0, es->num_entries will be obtained
+ *                from the first dentry.
+ * out:
+ *   es: pointer of entry set on success.
  * return:
- *   pointer of entry set on success,
- *   NULL on failure.
+ *   0 on success
+ *   -error code on failure
  */
-int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                struct super_block *sb, struct exfat_chain *p_dir, int entry,
-               unsigned int type)
+               unsigned int num_entries)
 {
        int ret, i, num_bh;
        unsigned int off;
        sector_t sec;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
-       struct exfat_dentry *ep;
-       int num_entries;
-       enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
        struct buffer_head *bh;
 
        if (p_dir->dir == DIR_DELETED) {
@@ -880,12 +876,18 @@ int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                return -EIO;
        es->bh[es->num_bh++] = bh;
 
-       ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
-       if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
-               goto put_es;
+       if (num_entries == ES_ALL_ENTRIES) {
+               struct exfat_dentry *ep;
+
+               ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
+               if (ep->type != EXFAT_FILE) {
+                       brelse(bh);
+                       return -EIO;
+               }
+
+               num_entries = ep->dentry.file.num_ext + 1;
+       }
 
-       num_entries = type == ES_ALL_ENTRIES ?
-               ep->dentry.file.num_ext + 1 : type;
        es->num_entries = num_entries;
 
        num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
@@ -918,8 +920,27 @@ int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                es->bh[es->num_bh++] = bh;
        }
 
+       return 0;
+
+put_es:
+       exfat_put_dentry_set(es, false);
+       return -EIO;
+}
+
+int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+               struct super_block *sb, struct exfat_chain *p_dir,
+               int entry, unsigned int num_entries)
+{
+       int ret, i;
+       struct exfat_dentry *ep;
+       enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY;
+
+       ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries);
+       if (ret < 0)
+               return ret;
+
        /* validate cached dentries */
-       for (i = ES_IDX_STREAM; i < num_entries; i++) {
+       for (i = ES_IDX_STREAM; i < es->num_entries; i++) {
                ep = exfat_get_dentry_cached(es, i);
                if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
                        goto put_es;

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 361595433480c46562765ad4d5c886a071005c25..037e8827a56fbc3fe71a71d7284bb2bacc16b971 100644 (file)
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -501,7 +501,7 @@ struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
                int num);
 int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                struct super_block *sb, struct exfat_chain *p_dir, int entry,
-               unsigned int type);
+               unsigned int num_entries);
 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync);
 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);