f2fs: return fs_trim if there is no candidate

If there is no candidate to submit discard command during f2fs_trim_fs, let's
return without checkpoint.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 917b5c5053aecaaf0a965834759f72ba94132213..ccea40763d9d8ffd4c70f4721783c0f99d989342 100644 (file)
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1249,6 +1249,11 @@ int write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
        /* this is the case of multiple fstrims without any changes */
        if (cpc->reason == CP_DISCARD) {
+               if (!exist_trim_candidates(sbi, cpc)) {
+                       unblock_operations(sbi);
+                       goto out;
+               }
+
                if (NM_I(sbi)->dirty_nat_cnt == 0 &&
                                SIT_I(sbi)->dirty_sentries == 0 &&
                                prefree_segments(sbi) == 0) {

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e0db895fd84c7c0429e152be602582b52c1b6886..a4e8e6278a17dd9f36387c12c88b8756383e6b91 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2119,6 +2119,7 @@ void release_discard_addrs(struct f2fs_sb_info *);
 int npages_for_summary_flush(struct f2fs_sb_info *, bool);
 void allocate_new_segments(struct f2fs_sb_info *);
 int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
+bool exist_trim_candidates(struct f2fs_sb_info *, struct cp_control *);
 struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
 void update_meta_page(struct f2fs_sb_info *, void *, block_t);
 void write_meta_page(struct f2fs_sb_info *, struct page *);

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 44d69f90be2a4392db5990f1f2b81e4037f85530..8b54b1fafa707742ebfb0d149269c5db7b5af1c9 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -834,7 +834,8 @@ done:
        SM_I(sbi)->nr_discards += end - start;
 }
 
-static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
+                                                       bool check_only)
 {
        int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
        int max_blocks = sbi->blocks_per_seg;
@@ -848,12 +849,12 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
        int i;
 
        if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
-               return;
+               return false;
 
        if (!force) {
                if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
                    SM_I(sbi)->nr_discards >= SM_I(sbi)->max_discards)
-                       return;
+                       return false;
        }
 
        /* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
@@ -871,8 +872,12 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
                                        && (end - start) < cpc->trim_minlen)
                        continue;
 
+               if (check_only)
+                       return true;
+
                __add_discard_entry(sbi, cpc, se, start, end);
        }
+       return false;
 }
 
 void release_discard_addrs(struct f2fs_sb_info *sbi)
@@ -1453,6 +1458,24 @@ static const struct segment_allocation default_salloc_ops = {
        .allocate_segment = allocate_segment_by_default,
 };
 
+bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+       __u64 trim_start = cpc->trim_start;
+       bool has_candidate = false;
+
+       mutex_lock(&SIT_I(sbi)->sentry_lock);
+       for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
+               if (add_discard_addrs(sbi, cpc, true)) {
+                       has_candidate = true;
+                       break;
+               }
+       }
+       mutex_unlock(&SIT_I(sbi)->sentry_lock);
+
+       cpc->trim_start = trim_start;
+       return has_candidate;
+}
+
 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
 {
        __u64 start = F2FS_BYTES_TO_BLK(range->start);
@@ -2249,7 +2272,7 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
                        /* add discard candidates */
                        if (cpc->reason != CP_DISCARD) {
                                cpc->trim_start = segno;
-                               add_discard_addrs(sbi, cpc);
+                               add_discard_addrs(sbi, cpc, false);
                        }
 
                        if (to_journal) {
@@ -2287,7 +2310,7 @@ out:
                __u64 trim_start = cpc->trim_start;
 
                for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
-                       add_discard_addrs(sbi, cpc);
+                       add_discard_addrs(sbi, cpc, false);
 
                cpc->trim_start = trim_start;
        }