/* * Unified UUID/GUID definition * * Copyright (C) 2009, 2016 Intel Corp. * Huang Ying * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation; * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include const u8 uuid_le_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; EXPORT_SYMBOL(uuid_le_index); const u8 uuid_be_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; EXPORT_SYMBOL(uuid_be_index); /*************************************************************** * Random UUID interface * * Used here for a Boot ID, but can be useful for other kernel * drivers. ***************************************************************/ /* * Generate random UUID */ void generate_random_uuid(unsigned char uuid[16]) { get_random_bytes(uuid, 16); /* Set UUID version to 4 --- truly random generation */ uuid[6] = (uuid[6] & 0x0F) | 0x40; /* Set the UUID variant to DCE */ uuid[8] = (uuid[8] & 0x3F) | 0x80; } EXPORT_SYMBOL(generate_random_uuid); static void __uuid_gen_common(__u8 b[16]) { prandom_bytes(b, 16); /* reversion 0b10 */ b[8] = (b[8] & 0x3F) | 0x80; } void uuid_le_gen(uuid_le *lu) { __uuid_gen_common(lu->b); /* version 4 : random generation */ lu->b[7] = (lu->b[7] & 0x0F) | 0x40; } EXPORT_SYMBOL_GPL(uuid_le_gen); void uuid_be_gen(uuid_be *bu) { __uuid_gen_common(bu->b); /* version 4 : random generation */ bu->b[6] = (bu->b[6] & 0x0F) | 0x40; } EXPORT_SYMBOL_GPL(uuid_be_gen); /** * uuid_is_valid - checks if UUID string valid * @uuid: UUID string to check * * Description: * It checks if the UUID string is following the format: * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx * where x is a hex digit. * * Return: true if input is valid UUID string. */ bool uuid_is_valid(const char *uuid) { unsigned int i; for (i = 0; i < UUID_STRING_LEN; i++) { if (i == 8 || i == 13 || i == 18 || i == 23) { if (uuid[i] != '-') return false; } else if (!isxdigit(uuid[i])) { return false; } } return true; } EXPORT_SYMBOL(uuid_is_valid); static int __uuid_to_bin(const char *uuid, __u8 b[16], const u8 ei[16]) { static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34}; unsigned int i; if (!uuid_is_valid(uuid)) return -EINVAL; for (i = 0; i < 16; i++) { int hi = hex_to_bin(uuid[si[i] + 0]); int lo = hex_to_bin(uuid[si[i] + 1]); b[ei[i]] = (hi << 4) | lo; } return 0; } int uuid_le_to_bin(const char *uuid, uuid_le *u) { return __uuid_to_bin(uuid, u->b, uuid_le_index); } EXPORT_SYMBOL(uuid_le_to_bin); int uuid_be_to_bin(const char *uuid, uuid_be *u) { return __uuid_to_bin(uuid, u->b, uuid_be_index); } EXPORT_SYMBOL(uuid_be_to_bin); linux/net-next.git/commit/include/pcmcia?h=nds-private-remove&id=f598f82e204ec0b17797caaf1b0311c52d43fb9a'>pcmcia
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authorColy Li <colyli@suse.de>2017-01-24 15:18:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-24 16:26:14 -0800
commitf598f82e204ec0b17797caaf1b0311c52d43fb9a (patch)
tree20e0109db50c168a36df14af76b484eaf9b71836 /include/pcmcia
parent4180c4c170a5a33b9987b314d248a9d572d89ab0 (diff)
romfs: use different way to generate fsid for BLOCK or MTD
Commit 8a59f5d25265 ("fs/romfs: return f_fsid for statfs(2)") generates a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev will triger an oops. Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y, both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined. Therefore when calling huge_encode_dev() to generate a 64bit id, I use the follow order to choose parameter, - CONFIG_ROMFS_ON_BLOCK defined use sb->s_bdev->bd_dev - CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined use sb->s_dev when, - both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined leave id as 0 When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index, otherwise sb->s_dev is 0. This is a try-best effort to generate a uniq file system ID, if all the above conditions are not meet, f_fsid of this romfs instance will be 0. Generally only one romfs can be built on single MTD block device, this method is enough to identify multiple romfs instances in a computer. Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de Signed-off-by: Coly Li <colyli@suse.de> Reported-by: Nong Li <nongli1031@gmail.com> Tested-by: Nong Li <nongli1031@gmail.com> Cc: Richard Weinberger <richard.weinberger@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/pcmcia')