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* grub-core/fs/ntfs.c: Eliminate useless divisions in favor of shifts.

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* grub-core/fs/ntfscomp.c: Likewise.
	* include/grub/ntfs.h (grub_ntfs_data): Replace spc with log_spc.
	(grub_ntfs_comp): Likewise.
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2013-01-05 17:36:04 +01:00
parent 21d1b9a029
commit 033d0b4b0b
4 changed files with 55 additions and 44 deletions
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47
grub-core/fs/ntfs.c
View file

@ -391,7 +391,7 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
grub_memset (&cc, 0, sizeof (cc));
ctx = &cc;
ctx->attr = at;
ctx->comp.spc = at->mft->data->spc;
ctx->comp.log_spc = at->mft->data->log_spc;
ctx->comp.disk = at->mft->data->disk;
if (pa[8] == 0)
@ -440,11 +440,11 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
at->save_pos = 1;
}
vcn = ctx->target_vcn = (ofs >> GRUB_NTFS_COM_LOG_LEN) * (GRUB_NTFS_COM_SEC / ctx->comp.spc);
vcn = ctx->target_vcn = (ofs >> GRUB_NTFS_COM_LOG_LEN) * (GRUB_NTFS_COM_SEC >> ctx->comp.log_spc);
ctx->target_vcn &= ~0xFULL;
}
else
vcn = ctx->target_vcn = grub_divmod64 (ofs >> GRUB_NTFS_BLK_SHR, ctx->comp.spc, 0);
vcn = ctx->target_vcn = ofs >> (GRUB_NTFS_BLK_SHR + ctx->comp.log_spc);
ctx->next_vcn = u32at (pa, 0x10);
ctx->curr_lcn = 0;
@ -459,17 +459,17 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
grub_disk_addr_t st0, st1;
grub_uint64_t m;
grub_divmod64 (ofs >> GRUB_NTFS_BLK_SHR, ctx->comp.spc, &m);
m = (ofs >> GRUB_NTFS_BLK_SHR) & ((1 << ctx->comp.log_spc) - 1);
st0 =
(ctx->target_vcn - ctx->curr_vcn + ctx->curr_lcn) * ctx->comp.spc + m;
((ctx->target_vcn - ctx->curr_vcn + ctx->curr_lcn) << ctx->comp.log_spc) + m;
st1 = st0 + 1;
if (st1 ==
(ctx->next_vcn - ctx->curr_vcn + ctx->curr_lcn) * ctx->comp.spc)
(ctx->next_vcn - ctx->curr_vcn + ctx->curr_lcn) << ctx->comp.log_spc)
{
if (grub_ntfs_read_run_list (ctx))
return grub_errno;
st1 = ctx->curr_lcn * ctx->comp.spc;
st1 = ctx->curr_lcn << ctx->comp.log_spc;
}
grub_set_unaligned32 (dest, grub_cpu_to_le32 (st0));
grub_set_unaligned32 (dest + 4, grub_cpu_to_le32 (st1));
@ -478,12 +478,10 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
if (!(ctx->flags & GRUB_NTFS_RF_COMP))
{
unsigned int pow;
if (!grub_fshelp_log2blksize (ctx->comp.spc, &pow))
grub_fshelp_read_file (ctx->comp.disk, (grub_fshelp_node_t) ctx,
read_hook, ofs, len, dest,
grub_ntfs_read_block, ofs + len, pow, 0);
grub_fshelp_read_file (ctx->comp.disk, (grub_fshelp_node_t) ctx,
read_hook, ofs, len, dest,
grub_ntfs_read_block, ofs + len,
ctx->comp.log_spc, 0);
return grub_errno;
}
@ -515,11 +513,11 @@ read_attr (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
/* If compression is possible make sure that we include possible
compressed block size. */
if (GRUB_NTFS_COM_SEC >= at->mft->data->spc)
if (GRUB_NTFS_LOG_COM_SEC >= at->mft->data->log_spc)
vcn = ((ofs >> GRUB_NTFS_COM_LOG_LEN)
* (GRUB_NTFS_COM_SEC / at->mft->data->spc)) & ~0xFULL;
<< (GRUB_NTFS_LOG_COM_SEC - at->mft->data->log_spc)) & ~0xFULL;
else
vcn = grub_divmod64 (ofs, at->mft->data->spc << GRUB_NTFS_BLK_SHR, 0);
vcn = ofs >> (at->mft->data->log_spc + GRUB_NTFS_BLK_SHR);
pa = at->attr_nxt + u16at (at->attr_nxt, 4);
while (pa < at->attr_end)
{
@ -934,6 +932,7 @@ grub_ntfs_mount (grub_disk_t disk)
{
struct grub_ntfs_bpb bpb;
struct grub_ntfs_data *data = 0;
grub_uint32_t spc;
if (!disk)
goto fail;
@ -955,23 +954,25 @@ grub_ntfs_mount (grub_disk_t disk)
|| (bpb.bytes_per_sector & (bpb.bytes_per_sector - 1)) != 0)
goto fail;
data->spc = (((grub_uint32_t) bpb.sectors_per_cluster
* (grub_uint32_t) grub_le_to_cpu16 (bpb.bytes_per_sector))
>> GRUB_NTFS_BLK_SHR);
if (!data->spc)
spc = (((grub_uint32_t) bpb.sectors_per_cluster
* (grub_uint32_t) grub_le_to_cpu16 (bpb.bytes_per_sector))
>> GRUB_NTFS_BLK_SHR);
if (spc == 0 || (spc & (spc - 1)))
goto fail;
for (data->log_spc = 0; (1U << data->log_spc) < spc; data->log_spc++);
if (bpb.clusters_per_mft > 0)
data->mft_size = data->spc * bpb.clusters_per_mft;
data->mft_size = bpb.clusters_per_mft << data->log_spc;
else
data->mft_size = 1 << (-bpb.clusters_per_mft - GRUB_NTFS_BLK_SHR);
if (bpb.clusters_per_index > 0)
data->idx_size = data->spc * bpb.clusters_per_index;
data->idx_size = bpb.clusters_per_index << data->log_spc;
else
data->idx_size = 1 << (-bpb.clusters_per_index - GRUB_NTFS_BLK_SHR);
data->mft_start = grub_le_to_cpu64 (bpb.mft_lcn) * data->spc;
data->mft_start = grub_le_to_cpu64 (bpb.mft_lcn) << data->log_spc;
if ((data->mft_size > GRUB_NTFS_MAX_MFT) || (data->idx_size > GRUB_NTFS_MAX_IDX))
goto fail;