From 387a8271207b4e921258194cf359039babbc33b9 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Thu, 13 Nov 2008 19:40:24 +0100 Subject: [PATCH] volume_id: fat - accept empty FAT32 fsinfo signature --- extras/volume_id/lib/fat.c | 14 ++++++++++---- extras/volume_id/lib/volume_id.c | 2 +- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/extras/volume_id/lib/fat.c b/extras/volume_id/lib/fat.c index 2d98b65b5..c0cfed82c 100644 --- a/extras/volume_id/lib/fat.c +++ b/extras/volume_id/lib/fat.c @@ -411,7 +411,11 @@ magic: fat32: info("looking for FAT32\n"); - /* FAT32 should have a valid signature in the fsinfo block */ + /* + * FAT32 should have a valid signature in the fsinfo block, + * but also allow all bytes set to '\0', because some volumes + * do not set the signature at all. + */ fsinfo_sect = le16_to_cpu(vs->type.fat32.fsinfo_sector); buf = volume_id_get_buffer(id, off + (fsinfo_sect * sector_size), 0x200); if (buf == NULL) @@ -423,11 +427,13 @@ fat32: info("signature2: 0x%02x%02x%02x%02x\n", fsinfo->signature2[0], fsinfo->signature2[1], fsinfo->signature2[2], fsinfo->signature2[3]); - if (memcmp(fsinfo->signature1, "\x52\x52\x61\x41", 4) != 0) + if (memcmp(fsinfo->signature1, "\x52\x52\x61\x41", 4) != 0 && + memcmp(fsinfo->signature1, "\x00\x00\x00\x00", 4) != 0) return -1; - if (memcmp(fsinfo->signature2, "\x72\x72\x41\x61", 4) != 0) + if (memcmp(fsinfo->signature2, "\x72\x72\x41\x61", 4) != 0 && + memcmp(fsinfo->signature2, "\x00\x00\x00\x00", 4) != 0) return -1 ; - info("FAT32 signatures match\n"); + info("FAT32 signatures ok\n"); vs = (struct vfat_super_block *) volume_id_get_buffer(id, off, 0x200); if (vs == NULL) diff --git a/extras/volume_id/lib/volume_id.c b/extras/volume_id/lib/volume_id.c index e4d2ed4cf..aaaab7ed7 100644 --- a/extras/volume_id/lib/volume_id.c +++ b/extras/volume_id/lib/volume_id.c @@ -418,7 +418,7 @@ int volume_id_probe_filesystem(struct volume_id *id, uint64_t off, uint64_t size * to make the filesystem detection successful. * * We do not want to read that many bytes from probed floppies, skip volumes - * smaller than a usual floppy disk + * smaller than a usual floppy disk. */ if (size > 1440 * 1024) { int found = 0; -- 2.30.2