[PATCH 1/4] f2fs: avoid very large discard command

[Jaegeuk Kim]

This patch adds MAX_DISCARD_BLOCKS() to avoid issuing too much large single
discard command.

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
 fs/f2fs/f2fs.h    | 3 ++-
 fs/f2fs/segment.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d076b94530bc..5f3fe97df055 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -133,7 +133,8 @@ enum {
                (SM_I(sbi)->trim_sections * (sbi)->segs_per_sec)
 #define BATCHED_TRIM_BLOCKS(sbi)       \
                (BATCHED_TRIM_SEGMENTS(sbi) << (sbi)->log_blocks_per_seg)
-
+#define MAX_DISCARD_BLOCKS(sbi)                                                
\
+               ((1 << (sbi)->log_blocks_per_seg) * (sbi)->segs_per_sec)
 #define DISCARD_ISSUE_RATE     8
 #define DEF_CP_INTERVAL                        60      /* 60 secs */
 #define DEF_IDLE_INTERVAL              5       /* 5 secs */
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index fe434cd872b4..567019940e9b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -886,7 +886,8 @@ static void __add_discard_entry(struct f2fs_sb_info *sbi,
        if (!list_empty(head)) {
                last = list_last_entry(head, struct discard_entry, list);
                if (START_BLOCK(sbi, cpc->trim_start) + start ==
-                                               last->blkaddr + last->len) {
+                               last->blkaddr + last->len &&
+                               last->len < MAX_DISCARD_BLOCKS(sbi)) {
                        last->len += end - start;
                        goto done;
                }
-- 
2.11.0