[PATCH 2/3] f2fs: introduce FITRIM in f2fs_ioctl

From: Jaegeuk Kim
Date: Tue Sep 23 2014 - 00:53:23 EST


This patch introduces FITRIM in f2fs_ioctl.
In this case, f2fs will issue small discards and prefree discards as many as
possible for the given area.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 4 +-
fs/f2fs/f2fs.h | 9 +++-
fs/f2fs/file.c | 29 ++++++++++++
fs/f2fs/segment.c | 110 +++++++++++++++++++++++++++++++++++++++-----
fs/f2fs/super.c | 1 +
include/trace/events/f2fs.h | 3 +-
6 files changed, 141 insertions(+), 15 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index e401ffd..5d793ba 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -997,7 +997,7 @@ void write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)

mutex_lock(&sbi->cp_mutex);

- if (!sbi->s_dirty)
+ if (!sbi->s_dirty && cpc->reason != CP_DISCARD)
goto out;
if (unlikely(f2fs_cp_error(sbi)))
goto out;
@@ -1020,7 +1020,7 @@ void write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)

/* write cached NAT/SIT entries to NAT/SIT area */
flush_nat_entries(sbi);
- flush_sit_entries(sbi);
+ flush_sit_entries(sbi, cpc);

/* unlock all the fs_lock[] in do_checkpoint() */
do_checkpoint(sbi, cpc);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5298924..7b1e1d2 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -99,10 +99,15 @@ enum {
enum {
CP_UMOUNT,
CP_SYNC,
+ CP_DISCARD,
};

struct cp_control {
int reason;
+ __u64 trim_start;
+ __u64 trim_end;
+ __u64 trim_minlen;
+ __u64 trimmed;
};

/*
@@ -1276,9 +1281,11 @@ void destroy_flush_cmd_control(struct f2fs_sb_info *);
void invalidate_blocks(struct f2fs_sb_info *, block_t);
void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
void clear_prefree_segments(struct f2fs_sb_info *);
+void release_discard_addrs(struct f2fs_sb_info *);
void discard_next_dnode(struct f2fs_sb_info *, block_t);
int npages_for_summary_flush(struct f2fs_sb_info *);
void allocate_new_segments(struct f2fs_sb_info *);
+int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
void write_meta_page(struct f2fs_sb_info *, struct page *);
void write_node_page(struct f2fs_sb_info *, struct page *,
@@ -1295,7 +1302,7 @@ void write_data_summaries(struct f2fs_sb_info *, block_t);
void write_node_summaries(struct f2fs_sb_info *, block_t);
int lookup_journal_in_cursum(struct f2fs_summary_block *,
int, unsigned int, int);
-void flush_sit_entries(struct f2fs_sb_info *);
+void flush_sit_entries(struct f2fs_sb_info *, struct cp_control *);
int build_segment_manager(struct f2fs_sb_info *);
void destroy_segment_manager(struct f2fs_sb_info *);
int __init create_segment_manager_caches(void);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ac8c680..1184207 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -860,6 +860,35 @@ out:
mnt_drop_write_file(filp);
return ret;
}
+ case FITRIM:
+ {
+ struct super_block *sb = inode->i_sb;
+ struct request_queue *q = bdev_get_queue(sb->s_bdev);
+ struct fstrim_range range;
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!blk_queue_discard(q))
+ return -EOPNOTSUPP;
+
+ if (copy_from_user(&range, (struct fstrim_range __user *)arg,
+ sizeof(range)))
+ return -EFAULT;
+
+ range.minlen = max((unsigned int)range.minlen,
+ q->limits.discard_granularity);
+ ret = f2fs_trim_fs(F2FS_SB(sb), &range);
+ if (ret < 0)
+ return ret;
+
+ if (copy_to_user((struct fstrim_range __user *)arg, &range,
+ sizeof(range)))
+ return -EFAULT;
+
+ return 0;
+ }
default:
return -ENOTTY;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 3125a3d..b423005 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -386,45 +386,92 @@ void discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
}
}

-static void add_discard_addrs(struct f2fs_sb_info *sbi,
- unsigned int segno, struct seg_entry *se)
+static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
{
struct list_head *head = &SM_I(sbi)->discard_list;
struct discard_entry *new;
int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
int max_blocks = sbi->blocks_per_seg;
+ struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
- unsigned long dmap[entries];
+ unsigned long *dmap;
unsigned int start = 0, end = -1;
+ bool force = (cpc->reason == CP_DISCARD);
int i;

- if (!test_opt(sbi, DISCARD))
+ if (!force && !test_opt(sbi, DISCARD))
return;

+ if (force && !se->valid_blocks) {
+ struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+ /*
+ * if this segment is registered in the prefree list, then
+ * we should skip adding a discard candidate, and let the
+ * checkpoint do that later.
+ */
+ mutex_lock(&dirty_i->seglist_lock);
+ if (test_bit(cpc->trim_start, dirty_i->dirty_segmap[PRE])) {
+ mutex_unlock(&dirty_i->seglist_lock);
+ cpc->trimmed += sbi->blocks_per_seg;
+ return;
+ }
+ mutex_unlock(&dirty_i->seglist_lock);
+
+ new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
+ INIT_LIST_HEAD(&new->list);
+ new->blkaddr = START_BLOCK(sbi, cpc->trim_start);
+ new->len = sbi->blocks_per_seg;
+ list_add_tail(&new->list, head);
+ SM_I(sbi)->nr_discards += sbi->blocks_per_seg;
+ cpc->trimmed += sbi->blocks_per_seg;
+ return;
+ }
+
/* zero block will be discarded through the prefree list */
if (!se->valid_blocks || se->valid_blocks == max_blocks)
return;

+ dmap = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+ if (!dmap)
+ return;
+
/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
for (i = 0; i < entries; i++)
dmap[i] = (cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];

- while (SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
+ while (force || SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
start = __find_rev_next_bit(dmap, max_blocks, end + 1);
if (start >= max_blocks)
break;

end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);

+ if (end - start < cpc->trim_minlen)
+ continue;
+
new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
INIT_LIST_HEAD(&new->list);
- new->blkaddr = START_BLOCK(sbi, segno) + start;
+ new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
new->len = end - start;
+ cpc->trimmed += end - start;

list_add_tail(&new->list, head);
SM_I(sbi)->nr_discards += end - start;
}
+ kfree(dmap);
+}
+
+void release_discard_addrs(struct f2fs_sb_info *sbi)
+{
+ struct list_head *head = &(SM_I(sbi)->discard_list);
+ struct discard_entry *entry, *this;
+
+ /* drop caches */
+ list_for_each_entry_safe(entry, this, head, list) {
+ list_del(&entry->list);
+ kmem_cache_free(discard_entry_slab, entry);
+ }
}

/*
@@ -897,6 +944,40 @@ static const struct segment_allocation default_salloc_ops = {
.allocate_segment = allocate_segment_by_default,
};

+int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
+{
+ block_t start_addr = SM_I(sbi)->main_blkaddr;
+ __u64 start = range->start >> sbi->log_blocksize;
+ __u64 end = start + (range->len >> sbi->log_blocksize) - 1;
+ __u64 segment = 1 << (sbi->log_blocksize + sbi->log_blocks_per_seg);
+ unsigned int start_segno, end_segno;
+ struct cp_control cpc;
+
+ if (range->minlen > segment || start >= TOTAL_BLKS(sbi) ||
+ range->len < sbi->blocksize)
+ return -EINVAL;
+
+ if (end <= start_addr)
+ goto out;
+
+ /* start/end segment number in main_area */
+ start_segno = (start <= start_addr) ? 0 : GET_SEGNO(sbi, start);
+ end_segno = (end >= TOTAL_BLKS(sbi)) ? TOTAL_SEGS(sbi) - 1 :
+ GET_SEGNO(sbi, end);
+
+ cpc.reason = CP_DISCARD;
+ cpc.trim_start = start_segno;
+ cpc.trim_end = end_segno;
+ cpc.trim_minlen = range->minlen >> sbi->log_blocksize;
+ cpc.trimmed = 0;
+
+ /* do checkpoint to issue discard commands safely */
+ write_checkpoint(sbi, &cpc);
+out:
+ range->len = cpc.trimmed << sbi->log_blocksize;
+ return 0;
+}
+
static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
{
struct curseg_info *curseg = CURSEG_I(sbi, type);
@@ -1524,7 +1605,7 @@ static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
* CP calls this function, which flushes SIT entries including sit_journal,
* and moves prefree segs to free segs.
*/
-void flush_sit_entries(struct f2fs_sb_info *sbi)
+void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
{
struct sit_info *sit_i = SIT_I(sbi);
unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
@@ -1534,6 +1615,7 @@ void flush_sit_entries(struct f2fs_sb_info *sbi)
struct list_head *head = &SM_I(sbi)->sit_entry_set;
unsigned long nsegs = TOTAL_SEGS(sbi);
bool to_journal = true;
+ struct seg_entry *se;

mutex_lock(&curseg->curseg_mutex);
mutex_lock(&sit_i->sentry_lock);
@@ -1580,11 +1662,14 @@ void flush_sit_entries(struct f2fs_sb_info *sbi)
/* flush dirty sit entries in region of current sit set */
for_each_set_bit_from(segno, bitmap, end) {
int offset, sit_offset;
- struct seg_entry *se = get_seg_entry(sbi, segno);
+
+ se = get_seg_entry(sbi, segno);

/* add discard candidates */
- if (SM_I(sbi)->nr_discards < SM_I(sbi)->max_discards)
- add_discard_addrs(sbi, segno, se);
+ if (SM_I(sbi)->nr_discards < SM_I(sbi)->max_discards) {
+ cpc->trim_start = segno;
+ add_discard_addrs(sbi, cpc);
+ }

if (to_journal) {
offset = lookup_journal_in_cursum(sum,
@@ -1614,8 +1699,11 @@ void flush_sit_entries(struct f2fs_sb_info *sbi)

f2fs_bug_on(sbi, !list_empty(head));
f2fs_bug_on(sbi, sit_i->dirty_sentries);
-
out:
+ if (cpc->reason == CP_DISCARD) {
+ for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
+ add_discard_addrs(sbi, cpc);
+ }
mutex_unlock(&sit_i->sentry_lock);
mutex_unlock(&curseg->curseg_mutex);

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 128c420..bb6b568 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -446,6 +446,7 @@ static void f2fs_put_super(struct super_block *sb)
* In addition, EIO will skip do checkpoint, we need this as well.
*/
release_dirty_inode(sbi);
+ release_discard_addrs(sbi);

iput(sbi->node_inode);
iput(sbi->meta_inode);
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 66eaace..bbc4de9 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -72,7 +72,8 @@
#define show_cpreason(type) \
__print_symbolic(type, \
{ CP_UMOUNT, "Umount" }, \
- { CP_SYNC, "Sync" })
+ { CP_SYNC, "Sync" }, \
+ { CP_DISCARD, "Discard" })

struct victim_sel_policy;

--
1.8.5.2 (Apple Git-48)

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