ext4: Allow reading files with non-zero offset, clamp read len

[u-boot] / fs / ext4 / ext4fs.c

diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 30787377708cb11db671a1342440faab16dcc662..7187dcfb0565566f0f778bd2191df7093a19a2e1 100644 (file)
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -65,8 +65,8 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
        short status;
 
        /* Adjust len so it we can't read past the end of the file. */
-       if (len > filesize)
-               len = filesize;
+       if (len + pos > filesize)
+               len = (filesize - pos);
 
        blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
 
@@ -190,12 +190,12 @@ int ext4fs_size(const char *filename, loff_t *size)
        return ext4fs_open(filename, size);
 }
 
-int ext4fs_read(char *buf, loff_t len, loff_t *actread)
+int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 {
        if (ext4fs_root == NULL || ext4fs_file == NULL)
-               return 0;
+               return -1;
 
-       return ext4fs_read_file(ext4fs_file, 0, len, buf, actread);
+       return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 }
 
 int ext4fs_probe(struct blk_desc *fs_dev_desc,
@@ -217,11 +217,6 @@ int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
        loff_t file_len;
        int ret;
 
-       if (offset != 0) {
-               printf("** Cannot support non-zero offset **\n");
-               return -1;
-       }
-
        ret = ext4fs_open(filename, &file_len);
        if (ret < 0) {
                printf("** File not found %s **\n", filename);
@@ -231,7 +226,7 @@ int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
        if (len == 0)
                len = file_len;
 
-       return ext4fs_read(buf, len, len_read);
+       return ext4fs_read(buf, offset, len, len_read);
 }
 
 int ext4fs_uuid(char *uuid_str)