The patch titled
Subject: include/uapi/linux/msdos_fs.h: use MSDOS_NAME for volume label size
has been added to the -mm tree. Its filename is
fat-replaced-11-magic-to-msdos_name-for-volume-label.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/fat-replaced-11-magic-to-msdos_name-for-volume-label.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/fat-replaced-11-magic-to-msdos_name-for-volume-label.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Carmeli Tamir <carmeli.tamir@xxxxxxxxx>
Subject: 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@xxxxxxxxx
Signed-off-by: Carmeli Tamir <carmeli.tamir@xxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/uapi/linux/msdos_fs.h~fat-replaced-11-magic-to-msdos_name-for-volume-label
+++ a/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;
_
Patches currently in -mm which might be from carmeli.tamir@xxxxxxxxx are
fat-replaced-11-magic-to-msdos_name-for-volume-label.patch
