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Date: Wed, 26 May 2021 16:43:33 +0800
From: Wang Jianchao <jianchao.wan9@...il.com>
To: Theodore Ts'o <tytso@....edu>,
Andreas Dilger <adilger.kernel@...ger.ca>
Cc: linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
lishujin@...ishou.com
Subject: [PATCH V2 4/7] ext4: add new helper interface ext4_insert_free_data
Split the codes that inserts and merges ext4_free_data structures
into a new interface ext4_insert_free_data. This is preparing for
following async background discard.
Signed-off-by: Wang Jianchao <wangjianchao@...ishou.com>
---
fs/ext4/mballoc.c | 96 +++++++++++++++++++++++++++++--------------------------
1 file changed, 51 insertions(+), 45 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 85418cf..16f06d2 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -350,6 +350,12 @@ static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
ext4_group_t group);
static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
+static inline struct ext4_free_data *efd_entry(struct rb_node *n)
+{
+ return rb_entry_safe(n, struct ext4_free_data, efd_node);
+}
+static int ext4_insert_free_data(struct ext4_sb_info *sbi,
+ struct rb_root *root, struct ext4_free_data *nfd);
/*
* The algorithm using this percpu seq counter goes below:
@@ -5069,28 +5075,53 @@ static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
kmem_cache_free(ext4_free_data_cachep, entry);
}
+static int ext4_insert_free_data(struct ext4_sb_info *sbi,
+ struct rb_root *root, struct ext4_free_data *nfd)
+{
+ struct rb_node **n = &root->rb_node;
+ struct rb_node *p = NULL;
+ struct ext4_free_data *fd;
+
+ while (*n) {
+ p = *n;
+ fd = rb_entry(p, struct ext4_free_data, efd_node);
+ if (nfd->efd_start_cluster < fd->efd_start_cluster)
+ n = &(*n)->rb_left;
+ else if (nfd->efd_start_cluster >=
+ (fd->efd_start_cluster + fd->efd_count))
+ n = &(*n)->rb_right;
+ else
+ return -EINVAL;
+ }
+
+ rb_link_node(&nfd->efd_node, p, n);
+ rb_insert_color(&nfd->efd_node, root);
+
+ /* Now try to see the extent can be merged to left and right */
+ fd = efd_entry(rb_prev(&nfd->efd_node));
+ if (fd)
+ ext4_try_merge_freed_extent(sbi, fd, nfd, root);
+
+ fd = efd_entry(rb_next(&nfd->efd_node));
+ if (fd)
+ ext4_try_merge_freed_extent(sbi, fd, nfd, root);
+
+ return 0;
+}
+
static noinline_for_stack int
ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
- struct ext4_free_data *new_entry)
+ struct ext4_free_data *nfd)
{
- ext4_group_t group = e4b->bd_group;
- ext4_grpblk_t cluster;
- ext4_grpblk_t clusters = new_entry->efd_count;
- struct ext4_free_data *entry;
struct ext4_group_info *db = e4b->bd_info;
struct super_block *sb = e4b->bd_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
- struct rb_node **n = &db->bb_free_root.rb_node, *node;
- struct rb_node *parent = NULL, *new_node;
BUG_ON(!ext4_handle_valid(handle));
BUG_ON(e4b->bd_bitmap_page == NULL);
BUG_ON(e4b->bd_buddy_page == NULL);
- new_node = &new_entry->efd_node;
- cluster = new_entry->efd_start_cluster;
-
- if (!*n) {
+ if (!db->bb_free_root.rb_node) {
/* first free block exent. We need to
protect buddy cache from being freed,
* otherwise we'll refresh it from
@@ -5099,44 +5130,19 @@ static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
get_page(e4b->bd_buddy_page);
get_page(e4b->bd_bitmap_page);
}
- while (*n) {
- parent = *n;
- entry = rb_entry(parent, struct ext4_free_data, efd_node);
- if (cluster < entry->efd_start_cluster)
- n = &(*n)->rb_left;
- else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
- n = &(*n)->rb_right;
- else {
- ext4_grp_locked_error(sb, group, 0,
- ext4_group_first_block_no(sb, group) +
- EXT4_C2B(sbi, cluster),
- "Block already on to-be-freed list");
- kmem_cache_free(ext4_free_data_cachep, new_entry);
- return 0;
- }
- }
-
- rb_link_node(new_node, parent, n);
- rb_insert_color(new_node, &db->bb_free_root);
-
- /* Now try to see the extent can be merged to left and right */
- node = rb_prev(new_node);
- if (node) {
- entry = rb_entry(node, struct ext4_free_data, efd_node);
- ext4_try_merge_freed_extent(sbi, entry, new_entry,
- &(db->bb_free_root));
- }
- node = rb_next(new_node);
- if (node) {
- entry = rb_entry(node, struct ext4_free_data, efd_node);
- ext4_try_merge_freed_extent(sbi, entry, new_entry,
- &(db->bb_free_root));
+ if (ext4_insert_free_data(sbi, &db->bb_free_root, nfd)) {
+ ext4_grp_locked_error(sb, e4b->bd_group, 0,
+ ext4_group_first_block_no(sb, e4b->bd_group) +
+ EXT4_C2B(sbi, nfd->efd_start_cluster),
+ "Block already on to-be-freed list");
+ kmem_cache_free(ext4_free_data_cachep, nfd);
+ return 0;
}
spin_lock(&sbi->s_md_lock);
- list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
- sbi->s_mb_free_pending += clusters;
+ list_add_tail(&nfd->efd_list, &sbi->s_freed_data_list);
+ sbi->s_mb_free_pending += nfd->efd_count;
spin_unlock(&sbi->s_md_lock);
return 0;
}
--
1.8.3.1
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