ext4: Allow reading files with non-zero offset, clamp read len
Support was already implemented, but not hooked up. This fixes several
fails in the test cases.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 3078737..7187dcf 100644
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -65,8 +65,8 @@
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 @@
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 @@
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 @@
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)