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Message-Id: <20230629144007.1263510-7-shikemeng@huaweicloud.com>
Date: Thu, 29 Jun 2023 22:40:05 +0800
From: Kemeng Shi <shikemeng@...weicloud.com>
To: tytso@....edu, adilger.kernel@...ger.ca, ojaswin@...ux.ibm.com
Cc: linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
shikemeng@...weicloud.com
Subject: [PATCH v5 6/8] ext4: call ext4_mb_mark_group_bb in ext4_group_add_blocks
call ext4_mb_mark_group_bb in ext4_group_add_blocks to remove repeat code
to update block bitmap and group descriptor on disk.
Note: ext4_group_add_blocks will update buddy and bitmap in two critical
sections instead of update in the same critical.
Originally:
ext4_mb_load_buddy_gfp
ext4_lock_group
mb_clear_bits(bitmap_bh, ...)
mb_free_blocks/ext4_mb_free_metadata
ext4_unlock_group
ext4_mb_unload_buddy
Now:
ext4_mb_load_buddy_gfp
ext4_lock_group
mb_clear_bits(bitmap_bh, ...)
ext4_unlock_group
/* no ext4_mb_init_cache for the same group will be called as
ext4_mb_load_buddy_gfp will ensure buddy page is update-to-date */
ext4_lock_group
mb_free_blocks/ext4_mb_free_metadata
ext4_unlock_group
ext4_mb_unload_buddy
As buddy page for group is always update-to-date between
ext4_mb_load_buddy_gfp and ext4_mb_unload_buddy. Then no
ext4_mb_init_cache will be called for the same group concurrentlly when
we update bitmap and buddy page betwwen buddy load and unload.
Signed-off-by: Kemeng Shi <shikemeng@...weicloud.com>
---
fs/ext4/mballoc.c | 92 +++++++++--------------------------------------
1 file changed, 17 insertions(+), 75 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 57cc304b724e..54254f08ea0c 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -6587,23 +6587,23 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
ext4_fsblk_t block, unsigned long count)
{
- struct buffer_head *bitmap_bh = NULL;
- struct buffer_head *gd_bh;
+ struct ext4_mark_context mc = {
+ .handle = handle,
+ .sb = sb,
+ .state = 0,
+ };
ext4_group_t block_group;
ext4_grpblk_t bit;
- unsigned int i;
- struct ext4_group_desc *desc;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_buddy e4b;
- int err = 0, ret, free_clusters_count;
- ext4_grpblk_t clusters_freed;
+ int err = 0;
ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
unsigned long cluster_count = last_cluster - first_cluster + 1;
ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
- if (count == 0)
+ if (cluster_count == 0)
return 0;
ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
@@ -6618,19 +6618,6 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
goto error_return;
}
- bitmap_bh = ext4_read_block_bitmap(sb, block_group);
- if (IS_ERR(bitmap_bh)) {
- err = PTR_ERR(bitmap_bh);
- bitmap_bh = NULL;
- goto error_return;
- }
-
- desc = ext4_get_group_desc(sb, block_group, &gd_bh);
- if (!desc) {
- err = -EIO;
- goto error_return;
- }
-
if (!ext4_sb_block_valid(sb, NULL, block, count)) {
ext4_error(sb, "Adding blocks in system zones - "
"Block = %llu, count = %lu",
@@ -6639,75 +6626,30 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
goto error_return;
}
- BUFFER_TRACE(bitmap_bh, "getting write access");
- err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
- EXT4_JTR_NONE);
- if (err)
- goto error_return;
-
- /*
- * We are about to modify some metadata. Call the journal APIs
- * to unshare ->b_data if a currently-committing transaction is
- * using it
- */
- BUFFER_TRACE(gd_bh, "get_write_access");
- err = ext4_journal_get_write_access(handle, sb, gd_bh, EXT4_JTR_NONE);
+ err = ext4_mb_load_buddy(sb, block_group, &e4b);
if (err)
goto error_return;
- for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
- BUFFER_TRACE(bitmap_bh, "clear bit");
- if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
- ext4_error(sb, "bit already cleared for block %llu",
- (ext4_fsblk_t)(block + i));
- BUFFER_TRACE(bitmap_bh, "bit already cleared");
- } else {
- clusters_freed++;
- }
- }
+ err = ext4_mb_mark_group_bb(&mc, block_group, bit, cluster_count,
+ EXT4_MB_BITMAP_MARKED_CHECK);
- err = ext4_mb_load_buddy(sb, block_group, &e4b);
- if (err)
+ if (err && mc.changed == 0) {
+ ext4_mb_unload_buddy(&e4b);
goto error_return;
+ }
- /*
- * need to update group_info->bb_free and bitmap
- * with group lock held. generate_buddy look at
- * them with group lock_held
- */
+ if (mc.changed != cluster_count)
+ ext4_error(sb, "bit already cleared in group %u",
+ block_group);
ext4_lock_group(sb, block_group);
- mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
mb_free_blocks(NULL, &e4b, bit, cluster_count);
- free_clusters_count = clusters_freed +
- ext4_free_group_clusters(sb, desc);
- ext4_free_group_clusters_set(sb, desc, free_clusters_count);
- ext4_block_bitmap_csum_set(sb, desc, bitmap_bh);
- ext4_group_desc_csum_set(sb, block_group, desc);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter,
- clusters_freed);
-
- if (sbi->s_log_groups_per_flex) {
- ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
- atomic64_add(clusters_freed,
- &sbi_array_rcu_deref(sbi, s_flex_groups,
- flex_group)->free_clusters);
- }
+ mc.changed);
ext4_mb_unload_buddy(&e4b);
- /* We dirtied the bitmap block */
- BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
- err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
-
- /* And the group descriptor block */
- BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
- ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
- if (!err)
- err = ret;
-
error_return:
- brelse(bitmap_bh);
ext4_std_error(sb, err);
return err;
}
--
2.30.0
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