[PATCH 15/18] fs: fat: search file should not allocate cluster

[Heinrich Schuchardt]

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.g...@gmx.de>
---
 fs/fat/fat_write.c | 29 ++++++-----------------------
 1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index a029ef8ed6..56ea28553b 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) {
--
2.29.2