From 6e5b93ee55d401f1619092fb675b57c28c9ed7ec Mon Sep 17 00:00:00 2001 From: Mike Lockwood Date: Mon, 8 Jul 2013 16:00:46 -0700 Subject: fatfs: add FAT_IOCTL_GET_VOLUME_ID This patch, originally from Android kernel, adds vfat ioctl command FAT_IOCTL_GET_VOLUME_ID, with this command we can get the vfat volume ID using following code: ioctl(fd, FAT_IOCTL_GET_VOLUME_ID, &volume_ID) This patch is a modified version of the patch by Mike Lockwood, with changes from Dmitry Pervushin, who noticed the original patch makes some volume IDs abiguous with error returns: for example, if volume id is 0xFFFFFDAD, that matches -ENOIOCTLCMD, we get "FFFFFFFF" from the user space. So add a parameter to ioctl to get the correct volume ID. Android uses vfat volume ID to identify different sd card, when a new sd card is inserted to device, android can scan the media on it and pop up new contents. Signed-off-by: Bintian Wang Cc: dmitry pervushin Cc: Mike Lockwood Cc: Colin Cross Acked-by: OGAWA Hirofumi Cc: John Stultz Cc: Sean McNeil Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/fat.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/fat/fat.h') diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 21664fcf3616..4241e6f39e86 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -86,6 +86,7 @@ struct msdos_sb_info { const void *dir_ops; /* Opaque; default directory operations */ int dir_per_block; /* dir entries per block */ int dir_per_block_bits; /* log2(dir_per_block) */ + unsigned int vol_id; /*volume ID*/ int fatent_shift; struct fatent_operations *fatent_ops; -- cgit v1.2.3