f2fs: trace checkpoint reason in fsync()

This patch slightly changes need_do_checkpoint to return the detail
info that indicates why we need do checkpoint, then caller could print
it with trace message.

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

3 files changed, 48 insertions, 22 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index cc46c22192ee..5c379a8ea075 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -913,6 +913,18 @@ enum need_lock_type {
         LOCK_RETRY,
 };
 
+enum cp_reason_type {
+        CP_NO_NEEDED,
+        CP_NON_REGULAR,
+        CP_HARDLINK,
+        CP_SB_NEED_CP,
+        CP_WRONG_PINO,
+        CP_NO_SPC_ROLL,
+        CP_NODE_NEED_CP,
+        CP_FASTBOOT_MODE,
+        CP_SPEC_LOG_NUM,
+};
+
 enum iostat_type {
         APP_DIRECT_IO,                  /* app direct IOs */
         APP_BUFFERED_IO,                /* app buffered IOs */
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 847e933e4a84..8742c028acc6 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -144,27 +144,29 @@ static int get_parent_ino(struct inode *inode, nid_t *pino)
         return 1;
 }
 
-static inline bool need_do_checkpoint(struct inode *inode)
+static inline enum cp_reason_type need_do_checkpoint(struct inode *inode)
 {
         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-        bool need_cp = false;
+        enum cp_reason_type cp_reason = CP_NO_NEEDED;
 
-        if (!S_ISREG(inode->i_mode) || inode->i_nlink != 1)
-                need_cp = true;
+        if (!S_ISREG(inode->i_mode))
+                cp_reason = CP_NON_REGULAR;
+        else if (inode->i_nlink != 1)
+                cp_reason = CP_HARDLINK;
         else if (is_sbi_flag_set(sbi, SBI_NEED_CP))
-                need_cp = true;
+                cp_reason = CP_SB_NEED_CP;
         else if (file_wrong_pino(inode))
-                need_cp = true;
+                cp_reason = CP_WRONG_PINO;
         else if (!space_for_roll_forward(sbi))
-                need_cp = true;
+                cp_reason = CP_NO_SPC_ROLL;
         else if (!is_checkpointed_node(sbi, F2FS_I(inode)->i_pino))
-                need_cp = true;
+                cp_reason = CP_NODE_NEED_CP;
         else if (test_opt(sbi, FASTBOOT))
-                need_cp = true;
+                cp_reason = CP_FASTBOOT_MODE;
         else if (sbi->active_logs == 2)
-                need_cp = true;
+                cp_reason = CP_SPEC_LOG_NUM;
 
-        return need_cp;
+        return cp_reason;
 }
 
 static bool need_inode_page_update(struct f2fs_sb_info *sbi, nid_t ino)
@@ -199,7 +201,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
         nid_t ino = inode->i_ino;
         int ret = 0;
-        bool need_cp = false;
+        enum cp_reason_type cp_reason = 0;
         struct writeback_control wbc = {
                 .sync_mode = WB_SYNC_ALL,
                 .nr_to_write = LONG_MAX,
@@ -218,7 +220,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
         clear_inode_flag(inode, FI_NEED_IPU);
 
         if (ret) {
-                trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
+                trace_f2fs_sync_file_exit(inode, cp_reason, datasync, ret);
                 return ret;
         }
 
@@ -249,10 +251,10 @@ go_write:
          * sudden-power-off.
          */
         down_read(&F2FS_I(inode)->i_sem);
-        need_cp = need_do_checkpoint(inode);
+        cp_reason = need_do_checkpoint(inode);
         up_read(&F2FS_I(inode)->i_sem);
 
-        if (need_cp) {
+        if (cp_reason) {
                 /* all the dirty node pages should be flushed for POR */
                 ret = f2fs_sync_fs(inode->i_sb, 1);
 
@@ -309,7 +311,7 @@ flush_out:
         }
         f2fs_update_time(sbi, REQ_TIME);
 out:
-        trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
+        trace_f2fs_sync_file_exit(inode, cp_reason, datasync, ret);
         f2fs_trace_ios(NULL, 1);
         return ret;
 }
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 009745564214..30d30399db02 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -136,6 +136,18 @@ TRACE_DEFINE_ENUM(CP_TRIMMED);
                 { CP_UMOUNT,    "Umount" },                             \
                 { CP_TRIMMED,   "Trimmed" })
 
+#define show_fsync_cpreason(type)                                       \
+        __print_symbolic(type,                                          \
+                { CP_NO_NEEDED,         "no needed" },                  \
+                { CP_NON_REGULAR,       "non regular" },                \
+                { CP_HARDLINK,          "hardlink" },                   \
+                { CP_SB_NEED_CP,        "sb needs cp" },                \
+                { CP_WRONG_PINO,        "wrong pino" },                 \
+                { CP_NO_SPC_ROLL,       "no space roll forward" },      \
+                { CP_NODE_NEED_CP,      "node needs cp" },              \
+                { CP_FASTBOOT_MODE,     "fastboot mode" },              \
+                { CP_SPEC_LOG_NUM,      "log type is 2" })
+
 struct victim_sel_policy;
 struct f2fs_map_blocks;
 
@@ -210,14 +222,14 @@ DEFINE_EVENT(f2fs__inode, f2fs_sync_file_enter,
 
 TRACE_EVENT(f2fs_sync_file_exit,
 
-        TP_PROTO(struct inode *inode, int need_cp, int datasync, int ret),
+        TP_PROTO(struct inode *inode, int cp_reason, int datasync, int ret),
 
-        TP_ARGS(inode, need_cp, datasync, ret),
+        TP_ARGS(inode, cp_reason, datasync, ret),
 
         TP_STRUCT__entry(
                 __field(dev_t,  dev)
                 __field(ino_t,  ino)
-                __field(int,    need_cp)
+                __field(int,    cp_reason)
                 __field(int,    datasync)
                 __field(int,    ret)
         ),
@@ -225,15 +237,15 @@ TRACE_EVENT(f2fs_sync_file_exit,
         TP_fast_assign(
                 __entry->dev            = inode->i_sb->s_dev;
                 __entry->ino            = inode->i_ino;
-                __entry->need_cp        = need_cp;
+                __entry->cp_reason      = cp_reason;
                 __entry->datasync       = datasync;
                 __entry->ret            = ret;
         ),
 
-        TP_printk("dev = (%d,%d), ino = %lu, checkpoint is %s, "
+        TP_printk("dev = (%d,%d), ino = %lu, cp_reason: %s, "
                 "datasync = %d, ret = %d",
                 show_dev_ino(__entry),
-                __entry->need_cp ? "needed" : "not needed",
+                show_fsync_cpreason(__entry->cp_reason),
                 __entry->datasync,
                 __entry->ret)
 );