f2fs: factor out victim_entry usage from general rb_tree use

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: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 28b1255..d1aa460 100644 (file)
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -204,29 +204,6 @@ 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,
@@ -335,7 +312,7 @@ lookup_neighbors:
 }
 
 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;
@@ -352,23 +329,12 @@ 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

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9c3ddeb..9396549 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -630,13 +630,8 @@ 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 {
@@ -4139,10 +4134,6 @@ void f2fs_leave_shrinker(struct f2fs_sb_info *sbi);
 bool sanity_check_extent_cache(struct inode *inode);
 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,
@@ -4153,7 +4144,7 @@ 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);

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 292a17d..2996d38 100644 (file)
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -390,40 +390,95 @@ 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,
@@ -459,19 +514,7 @@ 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,
@@ -481,7 +524,6 @@ 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;
@@ -508,12 +550,10 @@ 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;
 
@@ -555,8 +595,6 @@ 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;
@@ -566,25 +604,22 @@ 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;
 
@@ -610,24 +645,20 @@ next_node:
        }
 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);

diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 15bd1d6..5ad6ac6 100644 (file)
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -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;
 };
 

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 227e258..e98a12e 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1478,7 +1478,7 @@ retry:
                        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);
@@ -2965,7 +2965,7 @@ next:
        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,