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authorLukas Czerner <lczerner@redhat.com>2013-04-03 23:32:34 -0400
committerTheodore Ts'o <tytso@mit.edu>2013-04-03 23:32:34 -0400
commitbd86298e60b84b5e6d2da3e75c4ce2f6b70bdeed (patch)
tree8da632bbc3acfcc7e7416da820de87d56f2168a4 /fs/ext4
parent689110098c7df10fab8800d3bf8e727c21f426fb (diff)
downloadop-kernel-dev-bd86298e60b84b5e6d2da3e75c4ce2f6b70bdeed.zip
op-kernel-dev-bd86298e60b84b5e6d2da3e75c4ce2f6b70bdeed.tar.gz
ext4: introduce ext4_get_group_number()
Currently on many places in ext4 we're using ext4_get_group_no_and_offset() even though we're only interested in knowing the block group of the particular block, not the offset within the block group so we can use more efficient way to compute block group. This patch introduces ext4_get_group_number() which computes block group for a given block much more efficiently. Use this function instead of ext4_get_group_no_and_offset() everywhere where we're only interested in knowing the block group. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/balloc.c25
-rw-r--r--fs/ext4/ext4.h10
-rw-r--r--fs/ext4/mballoc.c6
-rw-r--r--fs/ext4/resize.c10
4 files changed, 33 insertions, 18 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index d6babf9..9e8d8ff 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -30,6 +30,23 @@ static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
*/
/*
+ * Calculate block group number for a given block number
+ */
+ext4_group_t ext4_get_group_number(struct super_block *sb,
+ ext4_fsblk_t block)
+{
+ ext4_group_t group;
+
+ if (test_opt2(sb, STD_GROUP_SIZE))
+ group = (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
+ block) >>
+ (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
+ else
+ ext4_get_group_no_and_offset(sb, block, &group, NULL);
+ return group;
+}
+
+/*
* Calculate the block group number and offset into the block/cluster
* allocation bitmap, given a block number
*/
@@ -59,13 +76,7 @@ static inline int ext4_block_in_group(struct super_block *sb,
{
ext4_group_t actual_group;
- if (test_opt2(sb, STD_GROUP_SIZE))
- actual_group =
- (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
- block) >>
- (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
- else
- ext4_get_group_no_and_offset(sb, block, &actual_group, NULL);
+ actual_group = ext4_get_group_number(sb, block);
return (actual_group == block_group) ? 1 : 0;
}
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index cc58aa8..a0637e5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1793,9 +1793,6 @@ ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
*/
#define ERR_BAD_DX_DIR -75000
-void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
- ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
-
/*
* Timeout and state flag for lazy initialization inode thread.
*/
@@ -1917,6 +1914,13 @@ int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
struct buffer_head *bh);
/* balloc.c */
+extern void ext4_get_group_no_and_offset(struct super_block *sb,
+ ext4_fsblk_t blocknr,
+ ext4_group_t *blockgrpp,
+ ext4_grpblk_t *offsetp);
+extern ext4_group_t ext4_get_group_number(struct super_block *sb,
+ ext4_fsblk_t block);
+
extern void ext4_validate_block_bitmap(struct super_block *sb,
struct ext4_group_desc *desc,
unsigned int block_group,
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 580aada..8c8d052 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3344,7 +3344,7 @@ static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
if (pa->pa_type == MB_GROUP_PA)
grp_blk--;
- ext4_get_group_no_and_offset(sb, grp_blk, &grp, NULL);
+ grp = ext4_get_group_number(sb, grp_blk);
/*
* possible race:
@@ -3809,7 +3809,7 @@ repeat:
list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
BUG_ON(pa->pa_type != MB_INODE_PA);
- ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
+ group = ext4_get_group_number(sb, pa->pa_pstart);
err = ext4_mb_load_buddy(sb, group, &e4b);
if (err) {
@@ -4071,7 +4071,7 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb,
list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
- ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
+ group = ext4_get_group_number(sb, pa->pa_pstart);
if (ext4_mb_load_buddy(sb, group, &e4b)) {
ext4_error(sb, "Error loading buddy information for %u",
group);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index c169477..e349853 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -272,7 +272,7 @@ next_group:
if (start_blk >= last_blk)
goto next_group;
group_data[bb_index].block_bitmap = start_blk++;
- ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
+ group = ext4_get_group_number(sb, start_blk - 1);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
if (flexbg_size > 1)
@@ -284,7 +284,7 @@ next_group:
if (start_blk >= last_blk)
goto next_group;
group_data[ib_index].inode_bitmap = start_blk++;
- ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
+ group = ext4_get_group_number(sb, start_blk - 1);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
if (flexbg_size > 1)
@@ -296,7 +296,7 @@ next_group:
if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
goto next_group;
group_data[it_index].inode_table = start_blk;
- ext4_get_group_no_and_offset(sb, start_blk, &group, NULL);
+ group = ext4_get_group_number(sb, start_blk - 1);
group -= group_data[0].group;
group_data[group].free_blocks_count -=
EXT4_SB(sb)->s_itb_per_group;
@@ -392,7 +392,7 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
ext4_group_t group;
int err;
- ext4_get_group_no_and_offset(sb, block, &group, NULL);
+ group = ext4_get_group_number(sb, block);
start = ext4_group_first_block_no(sb, group);
group -= flex_gd->groups[0].group;
@@ -1879,7 +1879,7 @@ retry:
/* Nothing need to do */
return 0;
- ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
+ n_group = ext4_get_group_number(sb, n_blocks_count - 1);
ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
n_desc_blocks = num_desc_blocks(sb, n_group + 1);
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