Hi Chao, On 02/22, Chao Yu wrote: > On 2016/12/31 2:51, Jaegeuk Kim wrote: > > If there is no candidate to submit discard command during f2sf_trim_fs, let's > > return without checkpoint. > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > > Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx> > > Please see comments below. > > > --- > > fs/f2fs/checkpoint.c | 5 +++++ > > fs/f2fs/f2fs.h | 1 + > > fs/f2fs/segment.c | 28 +++++++++++++++++++++++----- > > 3 files changed, 29 insertions(+), 5 deletions(-) > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > index 917b5c5053ae..ccea40763d9d 100644 > > --- 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 f2f40fce9d31..04d113f0d6bf 100644 > > --- 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 9a38424c3c1f..82078734f379 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -836,7 +836,8 @@ static void __add_discard_entry(struct f2fs_sb_info *sbi, > > 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; > > @@ -850,12 +851,12 @@ 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) */ > > @@ -873,8 +874,12 @@ 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) > > @@ -1455,6 +1460,19 @@ 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 (; trim_start <= cpc->trim_end; trim_start++) > > + if (add_discard_addrs(sbi, cpc, true)) > > + break; > > for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) > if (add_discard_addrs(sbi, cpc, true)) { > has_candidate = true; > break; > } Why do we need to do like this in which needs additional variable with multiple assignment? Thanks, > > cpc->trim_start = trim_start; > > > + mutex_unlock(&SIT_I(sbi)->sentry_lock); > > + > > + return trim_start <= cpc->trim_end; > > return has_candidate; > > Thanks, > > > +} > > + > > int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range) > > { > > __u64 start = F2FS_BYTES_TO_BLK(range->start); > > @@ -2251,7 +2269,7 @@ 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) { > > @@ -2289,7 +2307,7 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > __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; > > } > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel