From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Thu, 26 Nov 2020 15:10:01 +0000 (+0100)
Subject: fs: fat: search file should not allocate cluster
X-Git-Tag: v2021.10~377^2~6^2~14
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1e51c8d64a945946af72099dd469a3320ce02e7c;p=platform%2Fkernel%2Fu-boot.git

fs: fat: search file should not allocate cluster

Searching for a file is not a write operation. So it should not lead to the
allocation of a new cluster to the directory.

If we reuse deleted entries, we might not even use the new cluster and due
to not flushing it the directory could be corrupted.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index a029ef8..56ea285 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -1154,10 +1154,12 @@ static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
 	memcpy(dentptr->name, shortname, SHORT_NAME_SIZE);
 }
 
-/*
- * Find a directory entry based on filename or start cluster number
- * If the directory entry is not found,
- * the new position for writing a directory entry will be returned
+/**
+ * find_directory_entry() - find a directory entry by filename
+ *
+ * @itr:	directory iterator
+ * @filename:	name of file to find
+ * Return:	directory entry or NULL
  */
 static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
 {
@@ -1180,13 +1182,6 @@ static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
 			return itr->dent;
 	}
 
-	/* allocate a cluster for more entries */
-	if (!itr->dent &&
-	    (!itr->is_root || itr->fsdata->fatsize == 32) &&
-	    new_dir_table(itr))
-		/* indicate that allocating dent failed */
-		itr->dent = NULL;
-
 	return NULL;
 }
 
@@ -1348,12 +1343,6 @@ int file_fat_write_at(const char *filename, loff_t pos, void *buffer,
 			}
 		}
 
-		if (!itr->dent) {
-			printf("Error: allocating new dir entry\n");
-			ret = -EIO;
-			goto exit;
-		}
-
 		if (pos) {
 			/* No hole allowed */
 			ret = -EINVAL;
@@ -1622,12 +1611,6 @@ int fat_mkdir(const char *new_dirname)
 			}
 		}
 
-		if (!itr->dent) {
-			printf("Error: allocating new dir entry\n");
-			ret = -EIO;
-			goto exit;
-		}
-
 		/* Check if long name is needed */
 		ndent = set_name(itr, dirname, shortname);
 		if (ndent < 0) {