spl: add squashfs support

Implement spl_load_image_sqfs() in spl code.

This will be used in MMC to read a file from a squashfs partition.

Also, loosen squashfs read checks on file size by not failing when a
bigger size than the actual file size is requested. (Just read the file)
This is needed for FIT loading, because the length is ALIGNed.

Signed-off-by: Richard Genoud <[email protected]>
Reviewed-by: Miquel Raynal <[email protected]>
Reviewed-by: João Marcos Costa <[email protected]>

1 files changed, 5 insertions, 7 deletions

diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index 9cb8b4afcdd..543db8c7e9e 100644
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -1490,13 +1490,11 @@ static int sqfs_read_nest(const char *filename, void *buf, loff_t offset,
 		goto out;
 	}
 
-	/* If the user specifies a length, check its sanity */
-	if (len) {
-		if (len > finfo.size) {
-			ret = -EINVAL;
-			goto out;
-		}
-
+	/*
+	 * For FIT loading, the len is ALIGN, so it may exceed the actual size.
+	 * Let's just read the max.
+	 */
+	if (len && len < finfo.size) {
 		finfo.size = len;
 	} else {
 		len = finfo.size;