Re: [PATCH 2/3 v2] f2fs: factor out discard_cmd usage from general rb_tree use

This is a second part to remove the mixed use of rb_tree in discard_cmd from extent_cache.

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

[struct discard_cmd] [struct rb_entry] [0] struct rb_node rb_node; [0] struct rb_node rb_node; union { union { struct { struct { [16] block_t lstart; [12] unsigned int ofs; block_t len; unsigned int len; }; unsigned long long key; } __packed;

Cc: stable@vger.kernel.org Fixes: 004b68621897 ("f2fs: use rb-tree to track pending discard commands") Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org ---

Change log from v1: - fix a bug when spliting/merging discard commands

fs/f2fs/extent_cache.c | 36 +----- fs/f2fs/f2fs.h | 23 +--- fs/f2fs/segment.c | 249 +++++++++++++++++++++++++++-------------- 3 files changed, 169 insertions(+), 139 deletions(-)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index d1aa4609ca6b..5c206f941aac 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -192,7 +192,7 @@ static struct rb_entry *__lookup_rb_tree_slow(struct rb_root_cached *root, return NULL; }

-struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root, +static struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root, struct rb_entry *cached_re, unsigned int ofs) { struct rb_entry *re; @@ -204,7 +204,7 @@ struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root, return re; }

-struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi, +static struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi, struct rb_root_cached *root, struct rb_node **parent, unsigned int ofs, bool *leftmost) @@ -238,7 +238,7 @@ struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi, * in order to simplify the insertion after. * tree must stay unchanged between lookup and insertion. */ -struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root, +static struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root, struct rb_entry *cached_re, unsigned int ofs, struct rb_entry **prev_entry, @@ -311,36 +311,6 @@ struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root, return re; }

-bool f2fs_check_rb_tree_consistence(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 rb_entry *cur_re, *next_re; - - if (!cur) - return true; - - while (cur) { - next = rb_next(cur); - if (!next) - return true; - - cur_re = rb_entry(cur, struct rb_entry, rb_node); - next_re = rb_entry(next, struct rb_entry, rb_node); - - 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; - } - cur = next; - } -#endif - return true; -} - static struct kmem_cache *extent_tree_slab; static struct kmem_cache *extent_node_slab;

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9396549e112d..6e04fea9c34f 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -353,15 +353,7 @@ struct discard_info {

struct discard_cmd { struct rb_node rb_node; /* rb node located in rb-tree */ - union { - struct { - block_t lstart; /* logical start address */ - block_t len; /* length */ - block_t start; /* actual start address in dev */ - }; - struct discard_info di; /* discard info */ - - }; + struct discard_info di; /* discard info */ struct list_head list; /* command list */ struct completion wait; /* compleation */ struct block_device *bdev; /* bdev */ @@ -4132,19 +4124,6 @@ void f2fs_leave_shrinker(struct f2fs_sb_info *sbi); * extent_cache.c */ 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_for_insert(struct f2fs_sb_info *sbi, - struct rb_root_cached *root, - struct rb_node **parent, - unsigned int ofs, bool *leftmost); -struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root, - struct rb_entry *cached_re, unsigned int ofs, - struct rb_entry **prev_entry, struct rb_entry **next_entry, - 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); 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/segment.c b/fs/f2fs/segment.c index e98a12e8dca1..d135046108ef 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -933,9 +933,9 @@ static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi, dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS, true, NULL); INIT_LIST_HEAD(&dc->list); dc->bdev = bdev; - dc->lstart = lstart; - dc->start = start; - dc->len = len; + dc->di.lstart = lstart; + dc->di.start = start; + dc->di.len = len; dc->ref = 0; dc->state = D_PREP; dc->queued = 0; @@ -950,20 +950,108 @@ static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi, return dc; }

-static struct discard_cmd *__attach_discard_cmd(struct f2fs_sb_info *sbi, - struct block_device *bdev, block_t lstart, - block_t start, block_t len, - struct rb_node *parent, struct rb_node **p, - bool leftmost) +static bool f2fs_check_discard_tree(struct f2fs_sb_info *sbi) +{ +#ifdef CONFIG_F2FS_CHECK_FS + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; + struct rb_node *cur = rb_first_cached(&dcc->root), *next; + struct discard_cmd *cur_dc, *next_dc; + + while (cur) { + next = rb_next(cur); + if (!next) + return true; + + cur_dc = rb_entry(cur, struct discard_cmd, rb_node); + next_dc = rb_entry(next, struct discard_cmd, rb_node); + + if (cur_dc->di.lstart + cur_dc->di.len > next_dc->di.lstart) { + f2fs_info(sbi, "broken discard_rbtree, " + "cur(%u, %u) next(%u, %u)", + cur_dc->di.lstart, cur_dc->di.len, + next_dc->di.lstart, next_dc->di.len); + return false; + } + cur = next; + } +#endif + return true; +} + +static struct discard_cmd *__lookup_discard_cmd(struct f2fs_sb_info *sbi, + block_t blkaddr) { struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; + struct rb_node *node = dcc->root.rb_root.rb_node; struct discard_cmd *dc;

- dc = __create_discard_cmd(sbi, bdev, lstart, start, len); + while (node) { + dc = rb_entry(node, struct discard_cmd, rb_node);

- rb_link_node(&dc->rb_node, parent, p); - rb_insert_color_cached(&dc->rb_node, &dcc->root, leftmost); + if (blkaddr < dc->di.lstart) + node = node->rb_left; + else if (blkaddr >= dc->di.lstart + dc->di.len) + node = node->rb_right; + else + return dc; + } + return NULL; +} + +static struct discard_cmd *__lookup_discard_cmd_ret(struct rb_root_cached *root, + block_t blkaddr, + struct discard_cmd **prev_entry, + struct discard_cmd **next_entry, + struct rb_node ***insert_p, + struct rb_node **insert_parent) +{ + struct rb_node **pnode = &root->rb_root.rb_node; + struct rb_node *parent = NULL, *tmp_node; + struct discard_cmd *dc; + + *insert_p = NULL; + *insert_parent = NULL; + *prev_entry = NULL; + *next_entry = NULL; + + if (RB_EMPTY_ROOT(&root->rb_root)) + return NULL; + + while (*pnode) { + parent = *pnode; + dc = rb_entry(*pnode, struct discard_cmd, rb_node); + + if (blkaddr < dc->di.lstart) + pnode = &(*pnode)->rb_left; + else if (blkaddr >= dc->di.lstart + dc->di.len) + pnode = &(*pnode)->rb_right; + else + goto lookup_neighbors; + } + + *insert_p = pnode; + *insert_parent = parent; + + dc = rb_entry(parent, struct discard_cmd, rb_node); + tmp_node = parent; + if (parent && blkaddr > dc->di.lstart) + tmp_node = rb_next(parent); + *next_entry = rb_entry_safe(tmp_node, struct discard_cmd, rb_node); + + tmp_node = parent; + if (parent && blkaddr < dc->di.lstart) + tmp_node = rb_prev(parent); + *prev_entry = rb_entry_safe(tmp_node, struct discard_cmd, rb_node); + return NULL; + +lookup_neighbors: + /* lookup prev node for merging backward later */ + tmp_node = rb_prev(&dc->rb_node); + *prev_entry = rb_entry_safe(tmp_node, struct discard_cmd, rb_node);

+ /* lookup next node for merging frontward later */ + tmp_node = rb_next(&dc->rb_node); + *next_entry = rb_entry_safe(tmp_node, struct discard_cmd, rb_node); return dc; }

@@ -975,7 +1063,7 @@ static void __detach_discard_cmd(struct discard_cmd_control *dcc,

list_del(&dc->list); rb_erase_cached(&dc->rb_node, &dcc->root); - dcc->undiscard_blks -= dc->len; + dcc->undiscard_blks -= dc->di.len;

kmem_cache_free(discard_cmd_slab, dc);

@@ -988,7 +1076,7 @@ static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; unsigned long flags;

- trace_f2fs_remove_discard(dc->bdev, dc->start, dc->len); + trace_f2fs_remove_discard(dc->bdev, dc->di.start, dc->di.len);

spin_lock_irqsave(&dc->lock, flags); if (dc->bio_ref) { @@ -1006,7 +1094,7 @@ static void __remove_discard_cmd(struct f2fs_sb_info *sbi, printk_ratelimited( "%sF2FS-fs (%s): Issue discard(%u, %u, %u) failed, ret: %d", KERN_INFO, sbi->sb->s_id, - dc->lstart, dc->start, dc->len, dc->error); + dc->di.lstart, dc->di.start, dc->di.len, dc->error); __detach_discard_cmd(dcc, dc); }

@@ -1122,14 +1210,14 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi, if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) return 0;

- trace_f2fs_issue_discard(bdev, dc->start, dc->len); + trace_f2fs_issue_discard(bdev, dc->di.start, dc->di.len);

- lstart = dc->lstart; - start = dc->start; - len = dc->len; + lstart = dc->di.lstart; + start = dc->di.start; + len = dc->di.len; total_len = len;

- dc->len = 0; + dc->di.len = 0;

while (total_len && *issued < dpolicy->max_requests && !err) { struct bio *bio = NULL; @@ -1145,7 +1233,7 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi, if (*issued == dpolicy->max_requests) last = true;

- dc->len += len; + dc->di.len += len;

if (time_to_inject(sbi, FAULT_DISCARD)) { err = -EIO; @@ -1207,34 +1295,41 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi, return err; }

-static void __insert_discard_tree(struct f2fs_sb_info *sbi, +static void __insert_discard_cmd(struct f2fs_sb_info *sbi, struct block_device *bdev, block_t lstart, - block_t start, block_t len, - struct rb_node **insert_p, - struct rb_node *insert_parent) + block_t start, block_t len) { struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; - struct rb_node **p; + struct rb_node **p = &dcc->root.rb_root.rb_node; struct rb_node *parent = NULL; + struct discard_cmd *dc; bool leftmost = true;

- if (insert_p && insert_parent) { - parent = insert_parent; - p = insert_p; - goto do_insert; + /* look up rb tree to find parent node */ + while (*p) { + parent = *p; + dc = rb_entry(parent, struct discard_cmd, rb_node); + + if (lstart < dc->di.lstart) { + p = &(*p)->rb_left; + } else if (lstart >= dc->di.lstart + dc->di.len) { + p = &(*p)->rb_right; + leftmost = false; + } else { + f2fs_bug_on(sbi, 1); + } }

- p = f2fs_lookup_rb_tree_for_insert(sbi, &dcc->root, &parent, - lstart, &leftmost); -do_insert: - __attach_discard_cmd(sbi, bdev, lstart, start, len, parent, - p, leftmost); + dc = __create_discard_cmd(sbi, bdev, lstart, start, len); + + rb_link_node(&dc->rb_node, parent, p); + rb_insert_color_cached(&dc->rb_node, &dcc->root, leftmost); }

static void __relocate_discard_cmd(struct discard_cmd_control *dcc, struct discard_cmd *dc) { - list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->len)]); + list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->di.len)]); }

static void __punch_discard_cmd(struct f2fs_sb_info *sbi, @@ -1244,7 +1339,7 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi, struct discard_info di = dc->di; bool modified = false;

- if (dc->state == D_DONE || dc->len == 1) { + if (dc->state == D_DONE || dc->di.len == 1) { __remove_discard_cmd(sbi, dc); return; } @@ -1252,23 +1347,22 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi, dcc->undiscard_blks -= di.len;

if (blkaddr > di.lstart) { - dc->len = blkaddr - dc->lstart; - dcc->undiscard_blks += dc->len; + dc->di.len = blkaddr - dc->di.lstart; + dcc->undiscard_blks += dc->di.len; __relocate_discard_cmd(dcc, dc); modified = true; }

if (blkaddr < di.lstart + di.len - 1) { if (modified) { - __insert_discard_tree(sbi, dc->bdev, blkaddr + 1, + __insert_discard_cmd(sbi, dc->bdev, blkaddr + 1, di.start + blkaddr + 1 - di.lstart, - di.lstart + di.len - 1 - blkaddr, - NULL, NULL); + di.lstart + di.len - 1 - blkaddr); } else { - dc->lstart++; - dc->len--; - dc->start++; - dcc->undiscard_blks += dc->len; + dc->di.lstart++; + dc->di.len--; + dc->di.start++; + dcc->undiscard_blks += dc->di.len; __relocate_discard_cmd(dcc, dc); } } @@ -1287,17 +1381,14 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, SECTOR_TO_BLOCK(bdev_max_discard_sectors(bdev)); block_t end = lstart + len;

- dc = (struct discard_cmd *)f2fs_lookup_rb_tree_ret(&dcc->root, - NULL, lstart, - (struct rb_entry **)&prev_dc, - (struct rb_entry **)&next_dc, - &insert_p, &insert_parent, true, NULL); + dc = __lookup_discard_cmd_ret(&dcc->root, lstart, + &prev_dc, &next_dc, &insert_p, &insert_parent); if (dc) prev_dc = dc;

if (!prev_dc) { di.lstart = lstart; - di.len = next_dc ? next_dc->lstart - lstart : len; + di.len = next_dc ? next_dc->di.lstart - lstart : len; di.len = min(di.len, len); di.start = start; } @@ -1308,16 +1399,16 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, struct discard_cmd *tdc = NULL;

if (prev_dc) { - di.lstart = prev_dc->lstart + prev_dc->len; + di.lstart = prev_dc->di.lstart + prev_dc->di.len; if (di.lstart < lstart) di.lstart = lstart; if (di.lstart >= end) break;

- if (!next_dc || next_dc->lstart > end) + if (!next_dc || next_dc->di.lstart > end) di.len = end - di.lstart; else - di.len = next_dc->lstart - di.lstart; + di.len = next_dc->di.lstart - di.lstart; di.start = start + di.lstart - lstart; }

@@ -1350,10 +1441,9 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi, merged = true; }

- if (!merged) { - __insert_discard_tree(sbi, bdev, di.lstart, di.start, - di.len, NULL, NULL); - } + if (!merged) + __insert_discard_cmd(sbi, bdev, + di.lstart, di.start, di.len); next: prev_dc = next_dc; if (!prev_dc) @@ -1392,15 +1482,11 @@ static void __issue_discard_cmd_orderly(struct f2fs_sb_info *sbi, struct rb_node **insert_p = NULL, *insert_parent = NULL; struct discard_cmd *dc; struct blk_plug plug; - unsigned int pos = dcc->next_pos; bool io_interrupted = false;

mutex_lock(&dcc->cmd_lock); - dc = (struct discard_cmd *)f2fs_lookup_rb_tree_ret(&dcc->root, - NULL, pos, - (struct rb_entry **)&prev_dc, - (struct rb_entry **)&next_dc, - &insert_p, &insert_parent, true, NULL); + dc = __lookup_discard_cmd_ret(&dcc->root, dcc->next_pos, + &prev_dc, &next_dc, &insert_p, &insert_parent); if (!dc) dc = next_dc;

@@ -1418,7 +1504,7 @@ static void __issue_discard_cmd_orderly(struct f2fs_sb_info *sbi, break; }

- dcc->next_pos = dc->lstart + dc->len; + dcc->next_pos = dc->di.lstart + dc->di.len; err = __submit_discard_cmd(sbi, dpolicy, dc, issued);

if (*issued >= dpolicy->max_requests) @@ -1477,8 +1563,7 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, if (list_empty(pend_list)) goto next; if (unlikely(dcc->rbtree_check)) - f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi, - &dcc->root)); + f2fs_bug_on(sbi, !f2fs_check_discard_tree(sbi)); blk_start_plug(&plug); list_for_each_entry_safe(dc, tmp, pend_list, list) { f2fs_bug_on(sbi, dc->state != D_PREP); @@ -1556,7 +1641,7 @@ static unsigned int __wait_one_discard_bio(struct f2fs_sb_info *sbi, dc->ref--; if (!dc->ref) { if (!dc->error) - len = dc->len; + len = dc->di.len; __remove_discard_cmd(sbi, dc); } mutex_unlock(&dcc->cmd_lock); @@ -1579,14 +1664,15 @@ static unsigned int __wait_discard_cmd_range(struct f2fs_sb_info *sbi,

mutex_lock(&dcc->cmd_lock); list_for_each_entry_safe(iter, tmp, wait_list, list) { - if (iter->lstart + iter->len <= start || end <= iter->lstart) + if (iter->di.lstart + iter->di.len <= start || + end <= iter->di.lstart) continue; - if (iter->len < dpolicy->granularity) + if (iter->di.len < dpolicy->granularity) continue; if (iter->state == D_DONE && !iter->ref) { wait_for_completion_io(&iter->wait); if (!iter->error) - trimmed += iter->len; + trimmed += iter->di.len; __remove_discard_cmd(sbi, iter); } else { iter->ref++; @@ -1630,8 +1716,7 @@ static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr) bool need_wait = false;

mutex_lock(&dcc->cmd_lock); - dc = (struct discard_cmd *)f2fs_lookup_rb_tree(&dcc->root, - NULL, blkaddr); + dc = __lookup_discard_cmd(sbi, blkaddr); if (dc) { if (dc->state == D_PREP) { __punch_discard_cmd(sbi, dc, blkaddr); @@ -2964,24 +3049,20 @@ 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)); - - dc = (struct discard_cmd *)f2fs_lookup_rb_tree_ret(&dcc->root, - NULL, start, - (struct rb_entry **)&prev_dc, - (struct rb_entry **)&next_dc, - &insert_p, &insert_parent, true, NULL); + f2fs_bug_on(sbi, !f2fs_check_discard_tree(sbi)); + + dc = __lookup_discard_cmd_ret(&dcc->root, start, + &prev_dc, &next_dc, &insert_p, &insert_parent); if (!dc) dc = next_dc;

blk_start_plug(&plug);

- while (dc && dc->lstart <= end) { + while (dc && dc->di.lstart <= end) { struct rb_node *node; int err = 0;

- if (dc->len < dpolicy->granularity) + if (dc->di.len < dpolicy->granularity) goto skip;

if (dc->state != D_PREP) { @@ -2992,7 +3073,7 @@ static unsigned int __issue_discard_cmd_range(struct f2fs_sb_info *sbi, err = __submit_discard_cmd(sbi, dpolicy, dc, &issued);

if (issued >= dpolicy->max_requests) { - start = dc->lstart + dc->len; + start = dc->di.lstart + dc->di.len;

if (err) __remove_discard_cmd(sbi, dc);