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authorCarmeli Tamir <carmeli.tamir@gmail.com>2019-01-03 15:27:49 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-04 13:13:47 -0800
commit9da22854761a76c45d78aa2ae2b4bbd504b4f171 (patch)
treee15b67745c16ba387b32e674494ca9b902de44c8
parentf93ca1ed9ba09fa54d372ab17649d781384e34f7 (diff)
downloadlinux-9da22854761a76c45d78aa2ae2b4bbd504b4f171.tar.bz2
include/uapi/linux/msdos_fs.h: use MSDOS_NAME for volume label size
The FAT file system volume label file stored in the root directory should match the volume label field in the FAT boot sector. As consequence, the max length of these fields ought to be the same. This patch replaces the magic '11' usef in the struct fat_boot_sector with MSDOS_NAME, which is used in struct msdos_dir_entry. Please check the following references: 1. Microsoft FAT specification 2005 (http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf). Search for 'volume label'. 2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification (https://staff.washington.edu/dittrich/misc/fatgen103.pdf). Search for 'volume label'. 3. User space code that creates FAT filesystem sometimes uses MSDOS_NAME for the label, sometimes not. Search for 'if (memcmp(label, NO_NAME, MSDOS_NAME))'. I consider to make the same patch there as well. https://github.com/dosfstools/dosfstools/blob/master/src/mkfs.fat.c Link: http://lkml.kernel.org/r/1543096879-82837-1-git-send-email-carmeli.tamir@gmail.com Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jens Axboe <axboe@kernel.dk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/uapi/linux/msdos_fs.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h
index fde753735aba..1216e6caf59b 100644
--- a/include/uapi/linux/msdos_fs.h
+++ b/include/uapi/linux/msdos_fs.h
@@ -135,7 +135,7 @@ struct fat_boot_sector {
for mount state. */
__u8 signature; /* extended boot signature */
__u8 vol_id[4]; /* volume ID */
- __u8 vol_label[11]; /* volume label */
+ __u8 vol_label[MSDOS_NAME]; /* volume label */
__u8 fs_type[8]; /* file system type */
/* other fields are not added here */
} fat16;
@@ -158,7 +158,7 @@ struct fat_boot_sector {
for mount state. */
__u8 signature; /* extended boot signature */
__u8 vol_id[4]; /* volume ID */
- __u8 vol_label[11]; /* volume label */
+ __u8 vol_label[MSDOS_NAME]; /* volume label */
__u8 fs_type[8]; /* file system type */
/* other fields are not added here */
} fat32;