Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1429822

[PATCH v2 2/3] partition/efi: use bdev_logical_block_count()

From Arnd Bergmann <arnd@arndb.de>
Newsgroups linux.kernel
Subject [PATCH v2 2/3] partition/efi: use bdev_logical_block_count()
Date 2016-06-23 15:30 +0200
Message-ID <rNcRI-27f-13@gated-at.bofh.it> (permalink)
References <rNcRH-27f-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Enabling CONFIG_UBSAN_SANITIZE_ALL on ARM caused a link error:

last_lba.part.0':
:(.text+0xc3440): undefined reference to `____ilog2_NaN'
:(.text+0xc3538): undefined reference to `__aeabi_uldivmod'
:(.text+0xc38e8): undefined reference to `__aeabi_uldivmod'

This is caused by gcc not behaving in the expected ways with __builtin_constant_p(),
but it also points to somewhat inefficient code based on a 64-bit
division.

I have introduced a better bdev_logical_block_count() now, so we
can use that here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 block/partitions/efi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index bcd86e5cd546..7b1a62073d34 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -149,8 +149,8 @@ static u64 last_lba(struct block_device *bdev)
 {
 	if (!bdev || !bdev->bd_inode)
 		return 0;
-	return div_u64(bdev->bd_inode->i_size,
-		       bdev_logical_block_size(bdev)) - 1ULL;
+
+	return bdev_logical_block_count(bdev) - 1;
 }
 
 static inline int pmbr_part_valid(gpt_mbr_record *part)
-- 
2.9.0

Back to linux.kernel | Previous | Next | Find similar | Unroll thread


Thread

[PATCH v2 2/3] partition/efi: use bdev_logical_block_count() Arnd Bergmann <arnd@arndb.de> - 2016-06-23 15:30 +0200

csiph-web