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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2018-07-25 06:11:56 +0300 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2018-08-21 09:13:42 +0300 |
| commit | 6f8d4455060dfb0e32dfb8e685b97caf4ed1be41 (patch) | |
| tree | a0fad8fa5e8f4efc35784e22f3427e65e751e2e8 /fs/f2fs/gc.c | |
| parent | 853137cef46ccc490e6fd4b160a1c252d6459842 (diff) | |
| download | linux-6f8d4455060dfb0e32dfb8e685b97caf4ed1be41.tar.xz | |
f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc
The f2fs_gc() called by f2fs_balance_fs() requires to be called outside of
fi->i_gc_rwsem[WRITE], since f2fs_gc() can try to grab it in a loop.
If it hits the miximum retrials in GC, let's give a chance to release
gc_mutex for a short time in order not to go into live lock in the worst
case.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/gc.c')
| -rw-r--r-- | fs/f2fs/gc.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 76a22b3773bc..c598ae5ecbfa 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -882,6 +882,7 @@ next_step: if (!down_write_trylock( &F2FS_I(inode)->i_gc_rwsem[WRITE])) { iput(inode); + sbi->skipped_gc_rwsem++; continue; } @@ -911,6 +912,7 @@ next_step: continue; if (!down_write_trylock( &fi->i_gc_rwsem[WRITE])) { + sbi->skipped_gc_rwsem++; up_write(&fi->i_gc_rwsem[READ]); continue; } @@ -1048,6 +1050,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS), }; unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC]; + unsigned long long first_skipped; unsigned int skipped_round = 0, round = 0; trace_f2fs_gc_begin(sbi->sb, sync, background, @@ -1060,6 +1063,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, prefree_segments(sbi)); cpc.reason = __get_cp_reason(sbi); + sbi->skipped_gc_rwsem = 0; + first_skipped = last_skipped; gc_more: if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) { ret = -EINVAL; @@ -1101,7 +1106,8 @@ gc_more: total_freed += seg_freed; if (gc_type == FG_GC) { - if (sbi->skipped_atomic_files[FG_GC] > last_skipped) + if (sbi->skipped_atomic_files[FG_GC] > last_skipped || + sbi->skipped_gc_rwsem) skipped_round++; last_skipped = sbi->skipped_atomic_files[FG_GC]; round++; @@ -1110,15 +1116,23 @@ gc_more: if (gc_type == FG_GC) sbi->cur_victim_sec = NULL_SEGNO; - if (!sync) { - if (has_not_enough_free_secs(sbi, sec_freed, 0)) { - if (skipped_round > MAX_SKIP_ATOMIC_COUNT && - skipped_round * 2 >= round) - f2fs_drop_inmem_pages_all(sbi, true); + if (sync) + goto stop; + + if (has_not_enough_free_secs(sbi, sec_freed, 0)) { + if (skipped_round <= MAX_SKIP_GC_COUNT || + skipped_round * 2 < round) { segno = NULL_SEGNO; goto gc_more; } + if (first_skipped < last_skipped && + (last_skipped - first_skipped) > + sbi->skipped_gc_rwsem) { + f2fs_drop_inmem_pages_all(sbi, true); + segno = NULL_SEGNO; + goto gc_more; + } if (gc_type == FG_GC) ret = f2fs_write_checkpoint(sbi, &cpc); } |