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Date: Sat, 24 Jul 2021 15:41:21 +0800
From: Wang Jianchao <jianchao.wan9@...il.com>
To: linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: tytso@....edu, adilger.kernel@...ger.ca
Subject: [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
From: Wang Jianchao <wangjianchao@...ishou.com>
There is no functional change in this patch but just split the
codes, which serachs free block and does trim, into a new function
ext4_try_to_trim_range. This is preparing for the following async
backgroup discard.
Reviewed-by: Andreas Dilger <adilger@...ger.ca>
Signed-off-by: Wang Jianchao <wangjianchao@...ishou.com>
---
fs/ext4/mballoc.c | 102 ++++++++++++++++++++++++++--------------------
1 file changed, 57 insertions(+), 45 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 018d5d3c6eeb..e3844152a643 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -6218,6 +6218,54 @@ __acquires(bitlock)
return ret;
}
+static int ext4_try_to_trim_range(struct super_block *sb,
+ struct ext4_buddy *e4b, ext4_grpblk_t start,
+ ext4_grpblk_t max, ext4_grpblk_t minblocks)
+{
+ ext4_grpblk_t next, count, free_count;
+ void *bitmap;
+ int ret = 0;
+
+ bitmap = e4b->bd_bitmap;
+ start = (e4b->bd_info->bb_first_free > start) ?
+ e4b->bd_info->bb_first_free : start;
+ count = 0;
+ free_count = 0;
+
+ while (start <= max) {
+ start = mb_find_next_zero_bit(bitmap, max + 1, start);
+ if (start > max)
+ break;
+ next = mb_find_next_bit(bitmap, max + 1, start);
+
+ if ((next - start) >= minblocks) {
+ ret = ext4_trim_extent(sb, start, next - start, e4b);
+ if (ret && ret != -EOPNOTSUPP)
+ break;
+ ret = 0;
+ count += next - start;
+ }
+ free_count += next - start;
+ start = next + 1;
+
+ if (fatal_signal_pending(current)) {
+ count = -ERESTARTSYS;
+ break;
+ }
+
+ if (need_resched()) {
+ ext4_unlock_group(sb, e4b->bd_group);
+ cond_resched();
+ ext4_lock_group(sb, e4b->bd_group);
+ }
+
+ if ((e4b->bd_info->bb_free - free_count) < minblocks)
+ break;
+ }
+
+ return count;
+}
+
/**
* ext4_trim_all_free -- function to trim all free space in alloc. group
* @sb: super block for file system
@@ -6241,10 +6289,8 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
ext4_grpblk_t start, ext4_grpblk_t max,
ext4_grpblk_t minblocks)
{
- void *bitmap;
- ext4_grpblk_t next, count = 0, free_count = 0;
struct ext4_buddy e4b;
- int ret = 0;
+ int ret;
trace_ext4_trim_all_free(sb, group, start, max);
@@ -6254,57 +6300,23 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
ret, group);
return ret;
}
- bitmap = e4b.bd_bitmap;
ext4_lock_group(sb, group);
- if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
- minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
- goto out;
-
- start = (e4b.bd_info->bb_first_free > start) ?
- e4b.bd_info->bb_first_free : start;
- while (start <= max) {
- start = mb_find_next_zero_bit(bitmap, max + 1, start);
- if (start > max)
- break;
- next = mb_find_next_bit(bitmap, max + 1, start);
-
- if ((next - start) >= minblocks) {
- ret = ext4_trim_extent(sb, start, next - start, &e4b);
- if (ret && ret != -EOPNOTSUPP)
- break;
- ret = 0;
- count += next - start;
- }
- free_count += next - start;
- start = next + 1;
-
- if (fatal_signal_pending(current)) {
- count = -ERESTARTSYS;
- break;
- }
-
- if (need_resched()) {
- ext4_unlock_group(sb, group);
- cond_resched();
- ext4_lock_group(sb, group);
- }
-
- if ((e4b.bd_info->bb_free - free_count) < minblocks)
- break;
+ if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
+ minblocks < atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) {
+ ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks);
+ if (ret >= 0)
+ EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
+ } else {
+ ret = 0;
}
- if (!ret) {
- ret = count;
- EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
- }
-out:
ext4_unlock_group(sb, group);
ext4_mb_unload_buddy(&e4b);
ext4_debug("trimmed %d blocks in the group %d\n",
- count, group);
+ ret, group);
return ret;
}
--
2.17.1
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