grub2/0202-grub-core-fs-hfs.c-grub_hfs_read_file-Avoid-divmod64.patch

82 lines
2.6 KiB
Diff
Raw Normal View History

2013-06-07 18:03:56 +00:00
From 816fd37ee87127911c61b5464dfdd25145b36e1c Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sun, 10 Mar 2013 18:27:53 +0100
Subject: [PATCH 202/482] * grub-core/fs/hfs.c (grub_hfs_read_file):
Avoid divmod64 since the maximum size is 4G - 1 on hfs
---
ChangeLog | 5 +++++
grub-core/fs/hfs.c | 15 ++++++++-------
2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index bc51ae9..931ae8e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
2013-03-10 Vladimir Serbinenko <phcoder@gmail.com>
+ * grub-core/fs/hfs.c (grub_hfs_read_file): Avoid divmod64 since the
+ maximum size is 4G - 1 on hfs
+
+2013-03-10 Vladimir Serbinenko <phcoder@gmail.com>
+
Avoid costly 64-bit division in grub_get_time_ms on most platforms.
2013-03-10 Vladimir Serbinenko <phcoder@gmail.com>
diff --git a/grub-core/fs/hfs.c b/grub-core/fs/hfs.c
index 73ac7f9..14520c0 100644
--- a/grub-core/fs/hfs.c
+++ b/grub-core/fs/hfs.c
@@ -244,15 +244,16 @@ grub_hfs_block (struct grub_hfs_data *data, grub_hfs_datarecord_t dat,
static grub_ssize_t
grub_hfs_read_file (struct grub_hfs_data *data,
grub_disk_read_hook_t read_hook, void *read_hook_data,
- grub_off_t pos, grub_size_t len, char *buf)
+ grub_uint32_t pos, grub_size_t len, char *buf)
{
grub_off_t i;
grub_off_t blockcnt;
- blockcnt = grub_divmod64 (((len + pos)
- + data->blksz - 1), data->blksz, 0);
+ /* Files are at most 2G/4G - 1 bytes on hfs. Avoid 64-bit division.
+ Moreover len > 0 as checked in upper layer. */
+ blockcnt = (len + pos - 1) / data->blksz + 1;
- for (i = grub_divmod64 (pos, data->blksz, 0); i < blockcnt; i++)
+ for (i = pos / data->blksz; i < blockcnt; i++)
{
grub_disk_addr_t blknr;
grub_off_t blockoff;
@@ -260,7 +261,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
int skipfirst = 0;
- grub_divmod64 (pos, data->blksz, &blockoff);
+ blockoff = pos % data->blksz;
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno)
@@ -269,7 +270,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
/* Last block. */
if (i == blockcnt - 1)
{
- grub_divmod64 ((len + pos), data->blksz, &blockend);
+ blockend = (len + pos) % data->blksz;
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (! blockend)
@@ -277,7 +278,7 @@ grub_hfs_read_file (struct grub_hfs_data *data,
}
/* First block. */
- if (i == grub_divmod64 (pos, data->blksz, 0))
+ if (i == pos / data->blksz)
{
skipfirst = blockoff;
blockend -= skipfirst;
--
2013-06-07 18:03:56 +00:00
1.8.2.1