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f2fs: factor out victim_entry usage from general rb_tree use
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[ Upstream commit 043d2d0 ]

Let's reduce the complexity of mixed use of rb_tree in victim_entry from
extent_cache and discard_cmd.

This should fix arm32 memory alignment issue caused by shared rb_entry.

[struct victim_entry]              [struct rb_entry]
[0] struct rb_node rb_node;        [0] struct rb_node rb_node;
                                       union {
                                         struct {
                                           unsigned int ofs;
                                           unsigned int len;
                                         };
[16] unsigned long long mtime;     [12] unsigned long long key;
                                       } __packed;

Cc: <stable@vger.kernel.org>
Fixes: 093749e ("f2fs: support age threshold based garbage collection")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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@gregkh
Jaegeuk Kim authored and gregkh committed May 17, 2023
1 parent 4377b1d commit cba2856
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Showing 5 changed files with 93 additions and 115 deletions.
36 changes: 1 addition & 35 deletions fs/f2fs/extent_cache.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -149,29 +149,6 @@ struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root,
return re;
}

struct rb_node **f2fs_lookup_rb_tree_ext(struct f2fs_sb_info *sbi,
struct rb_root_cached *root,
struct rb_node **parent,
unsigned long long key, bool *leftmost)
{
struct rb_node **p = &root->rb_root.rb_node;
struct rb_entry *re;

while (*p) {
*parent = *p;
re = rb_entry(*parent, struct rb_entry, rb_node);

if (key < re->key) {
p = &(*p)->rb_left;
} else {
p = &(*p)->rb_right;
*leftmost = false;
}
}

return p;
}

struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
struct rb_root_cached *root,
struct rb_node **parent,
Expand Down Expand Up @@ -280,7 +257,7 @@ struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
}

bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
struct rb_root_cached *root, bool check_key)
struct rb_root_cached *root)
{
#ifdef CONFIG_F2FS_CHECK_FS
struct rb_node *cur = rb_first_cached(root), *next;
Expand All @@ -297,23 +274,12 @@ bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
cur_re = rb_entry(cur, struct rb_entry, rb_node);
next_re = rb_entry(next, struct rb_entry, rb_node);

if (check_key) {
if (cur_re->key > next_re->key) {
f2fs_info(sbi, "inconsistent rbtree, "
"cur(%llu) next(%llu)",
cur_re->key, next_re->key);
return false;
}
goto next;
}

if (cur_re->ofs + cur_re->len > next_re->ofs) {
f2fs_info(sbi, "inconsistent rbtree, cur(%u, %u) next(%u, %u)",
cur_re->ofs, cur_re->len,
next_re->ofs, next_re->len);
return false;
}
next:
cur = next;
}
#endif
Expand Down
15 changes: 3 additions & 12 deletions fs/f2fs/f2fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -612,13 +612,8 @@ enum extent_type {

struct rb_entry {
struct rb_node rb_node; /* rb node located in rb-tree */
union {
struct {
unsigned int ofs; /* start offset of the entry */
unsigned int len; /* length of the entry */
};
unsigned long long key; /* 64-bits key */
} __packed;
unsigned int ofs; /* start offset of the entry */
unsigned int len; /* length of the entry */
};

struct extent_info {
Expand Down Expand Up @@ -4132,10 +4127,6 @@ void f2fs_leave_shrinker(struct f2fs_sb_info *sbi);
*/
struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root,
struct rb_entry *cached_re, unsigned int ofs);
struct rb_node **f2fs_lookup_rb_tree_ext(struct f2fs_sb_info *sbi,
struct rb_root_cached *root,
struct rb_node **parent,
unsigned long long key, bool *left_most);
struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
struct rb_root_cached *root,
struct rb_node **parent,
Expand All @@ -4146,7 +4137,7 @@ struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
struct rb_node ***insert_p, struct rb_node **insert_parent,
bool force, bool *leftmost);
bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
struct rb_root_cached *root, bool check_key);
struct rb_root_cached *root);
void f2fs_init_extent_tree(struct inode *inode);
void f2fs_drop_extent_tree(struct inode *inode);
void f2fs_destroy_extent_node(struct inode *inode);
Expand Down
139 changes: 85 additions & 54 deletions fs/f2fs/gc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -389,40 +389,95 @@ static unsigned int count_bits(const unsigned long *addr,
return sum;
}

static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
unsigned long long mtime, unsigned int segno,
struct rb_node *parent, struct rb_node **p,
bool left_most)
static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
struct rb_root_cached *root)
{
#ifdef CONFIG_F2FS_CHECK_FS
struct rb_node *cur = rb_first_cached(root), *next;
struct victim_entry *cur_ve, *next_ve;

while (cur) {
next = rb_next(cur);
if (!next)
return true;

cur_ve = rb_entry(cur, struct victim_entry, rb_node);
next_ve = rb_entry(next, struct victim_entry, rb_node);

if (cur_ve->mtime > next_ve->mtime) {
f2fs_info(sbi, "broken victim_rbtree, "
"cur_mtime(%llu) next_mtime(%llu)",
cur_ve->mtime, next_ve->mtime);
return false;
}
cur = next;
}
#endif
return true;
}

static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
unsigned long long mtime)
{
struct atgc_management *am = &sbi->am;
struct rb_node *node = am->root.rb_root.rb_node;
struct victim_entry *ve = NULL;

while (node) {
ve = rb_entry(node, struct victim_entry, rb_node);

if (mtime < ve->mtime)
node = node->rb_left;
else
node = node->rb_right;
}
return ve;
}

static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
unsigned long long mtime, unsigned int segno)
{
struct atgc_management *am = &sbi->am;
struct victim_entry *ve;

ve = f2fs_kmem_cache_alloc(victim_entry_slab,
GFP_NOFS, true, NULL);
ve = f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS, true, NULL);

ve->mtime = mtime;
ve->segno = segno;

rb_link_node(&ve->rb_node, parent, p);
rb_insert_color_cached(&ve->rb_node, &am->root, left_most);

list_add_tail(&ve->list, &am->victim_list);

am->victim_count++;

return ve;
}

static void insert_victim_entry(struct f2fs_sb_info *sbi,
static void __insert_victim_entry(struct f2fs_sb_info *sbi,
unsigned long long mtime, unsigned int segno)
{
struct atgc_management *am = &sbi->am;
struct rb_node **p;
struct rb_root_cached *root = &am->root;
struct rb_node **p = &root->rb_root.rb_node;
struct rb_node *parent = NULL;
struct victim_entry *ve;
bool left_most = true;

p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
/* look up rb tree to find parent node */
while (*p) {
parent = *p;
ve = rb_entry(parent, struct victim_entry, rb_node);

if (mtime < ve->mtime) {
p = &(*p)->rb_left;
} else {
p = &(*p)->rb_right;
left_most = false;
}
}

ve = __create_victim_entry(sbi, mtime, segno);

rb_link_node(&ve->rb_node, parent, p);
rb_insert_color_cached(&ve->rb_node, root, left_most);
}

static void add_victim_entry(struct f2fs_sb_info *sbi,
Expand Down Expand Up @@ -458,19 +513,7 @@ static void add_victim_entry(struct f2fs_sb_info *sbi,
if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
return;

insert_victim_entry(sbi, mtime, segno);
}

static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
struct victim_sel_policy *p)
{
struct atgc_management *am = &sbi->am;
struct rb_node *parent = NULL;
bool left_most;

f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);

return parent;
__insert_victim_entry(sbi, mtime, segno);
}

static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
Expand All @@ -480,7 +523,6 @@ static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
struct atgc_management *am = &sbi->am;
struct rb_root_cached *root = &am->root;
struct rb_node *node;
struct rb_entry *re;
struct victim_entry *ve;
unsigned long long total_time;
unsigned long long age, u, accu;
Expand All @@ -507,12 +549,10 @@ static void atgc_lookup_victim(struct f2fs_sb_info *sbi,

node = rb_first_cached(root);
next:
re = rb_entry_safe(node, struct rb_entry, rb_node);
if (!re)
ve = rb_entry_safe(node, struct victim_entry, rb_node);
if (!ve)
return;

ve = (struct victim_entry *)re;

if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
goto skip;

Expand Down Expand Up @@ -554,8 +594,6 @@ static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
{
struct sit_info *sit_i = SIT_I(sbi);
struct atgc_management *am = &sbi->am;
struct rb_node *node;
struct rb_entry *re;
struct victim_entry *ve;
unsigned long long age;
unsigned long long max_mtime = sit_i->dirty_max_mtime;
Expand All @@ -565,25 +603,22 @@ static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
unsigned int dirty_threshold = max(am->max_candidate_count,
am->candidate_ratio *
am->victim_count / 100);
unsigned int cost;
unsigned int iter = 0;
unsigned int cost, iter;
int stage = 0;

if (max_mtime < min_mtime)
return;
max_mtime += 1;
next_stage:
node = lookup_central_victim(sbi, p);
iter = 0;
ve = __lookup_victim_entry(sbi, p->age);
next_node:
re = rb_entry_safe(node, struct rb_entry, rb_node);
if (!re) {
if (stage == 0)
goto skip_stage;
if (!ve) {
if (stage++ == 0)
goto next_stage;
return;
}

ve = (struct victim_entry *)re;

if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
goto skip_node;

Expand All @@ -609,24 +644,20 @@ static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
}
skip_node:
if (iter < dirty_threshold) {
if (stage == 0)
node = rb_prev(node);
else if (stage == 1)
node = rb_next(node);
ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
rb_next(&ve->rb_node),
struct victim_entry, rb_node);
goto next_node;
}
skip_stage:
if (stage < 1) {
stage++;
iter = 0;

if (stage++ == 0)
goto next_stage;
}
}

static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
struct victim_sel_policy *p)
{
f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
&sbi->am.root, true));
f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));

if (p->gc_mode == GC_AT)
atgc_lookup_victim(sbi, p);
Expand Down
14 changes: 2 additions & 12 deletions fs/f2fs/gc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -55,20 +55,10 @@ struct gc_inode_list {
struct radix_tree_root iroot;
};

struct victim_info {
unsigned long long mtime; /* mtime of section */
unsigned int segno; /* section No. */
};

struct victim_entry {
struct rb_node rb_node; /* rb node located in rb-tree */
union {
struct {
unsigned long long mtime; /* mtime of section */
unsigned int segno; /* segment No. */
};
struct victim_info vi; /* victim info */
};
unsigned long long mtime; /* mtime of section */
unsigned int segno; /* segment No. */
struct list_head list;
};

Expand Down
4 changes: 2 additions & 2 deletions fs/f2fs/segment.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1474,7 +1474,7 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
goto next;
if (unlikely(dcc->rbtree_check))
f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
&dcc->root, false));
&dcc->root));
blk_start_plug(&plug);
list_for_each_entry_safe(dc, tmp, pend_list, list) {
f2fs_bug_on(sbi, dc->state != D_PREP);
Expand Down Expand Up @@ -3002,7 +3002,7 @@ static unsigned int __issue_discard_cmd_range(struct f2fs_sb_info *sbi,
mutex_lock(&dcc->cmd_lock);
if (unlikely(dcc->rbtree_check))
f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
&dcc->root, false));
&dcc->root));

dc = (struct discard_cmd *)f2fs_lookup_rb_tree_ret(&dcc->root,
NULL, start,
Expand Down

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