[PATCH RFC 5/8] fs: fat: rely on higher layer to get block aligned read range

[Qu Wenruo <wqu@suse.com>]

Just implement fat_get_blocksize() for fat, so that fat_read_file()
always get a block aligned read range.

Unfortunately I'm not experienced enough to cleanup the fat code, thus
further cleanup is appreciated.

Cc: Tom Rini <trini@konsulko.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/fat/fat.c  | 13 +++++++++++++
 fs/fs.c       |  2 +-
 include/fat.h |  1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index dcceccbcee0a..e13035e8e6d1 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -1299,6 +1299,19 @@ int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 	return ret;
 }
 
+int fat_get_blocksize(const char *filename)
+{
+	fsdata fsdata = {0};
+	int ret;
+
+	ret = get_fs_info(&fsdata);
+	if (ret)
+		return ret;
+
+	free(fsdata.fatbuf);
+	return fsdata.sect_size;
+}
+
 typedef struct {
 	struct fs_dir_stream parent;
 	struct fs_dirent dirent;
diff --git a/fs/fs.c b/fs/fs.c
index e69a0968bb6d..7e4ead9b790b 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -207,7 +207,7 @@ static struct fstype_info fstypes[] = {
 		.exists = fat_exists,
 		.size = fat_size,
 		.read = fat_read_file,
-		.get_blocksize = fs_get_blocksize_unsupported,
+		.get_blocksize = fat_get_blocksize,
 #if CONFIG_IS_ENABLED(FAT_WRITE)
 		.write = file_fat_write,
 		.unlink = fat_unlink,
diff --git a/include/fat.h b/include/fat.h
index a9756fb4cd1b..c03a2bebecef 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -201,6 +201,7 @@ int file_fat_detectfs(void);
 int fat_exists(const char *filename);
 int fat_size(const char *filename, loff_t *size);
 int file_fat_read(const char *filename, void *buffer, int maxsize);
+int fat_get_blocksize(const char *filename);
 int fat_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info);
 int fat_register_device(struct blk_desc *dev_desc, int part_no);
 
-- 
2.36.1