From: Zhang Yi After mpage_map_and_submit_extent() supports restarting handle if credits are insufficient during allocating blocks, it is more likely to exit the current mapping iteration and continue to process the current processing partially mapped folio again. The existing tracepoints are not sufficient to track this situation, so enhance the tracepoints to track the writeback position and the return value before and after submitting the folios. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/inode.c | 5 ++++- include/trace/events/ext4.h | 42 ++++++++++++++++++++++++++++++++----- 2 files changed, 41 insertions(+), 6 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 10d4f86a5c15..51effbad90e5 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2935,7 +2935,8 @@ static int ext4_do_writepages(struct mpage_da_data *mpd) } mpd->do_map = 1; - trace_ext4_da_write_pages(inode, mpd->start_pos, wbc); + trace_ext4_da_write_folios_start(inode, mpd->start_pos, + mpd->next_pos, wbc); ret = mpage_prepare_extent_to_map(mpd); if (!ret && mpd->map.m_len) ret = mpage_map_and_submit_extent(handle, mpd, @@ -2973,6 +2974,8 @@ static int ext4_do_writepages(struct mpage_da_data *mpd) } else ext4_put_io_end(mpd->io_submit.io_end); mpd->io_submit.io_end = NULL; + trace_ext4_da_write_folios_end(inode, mpd->start_pos, + mpd->next_pos, wbc, ret); if (ret == -ENOSPC && sbi->s_journal) { /* diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index 62d52997b5c6..845451077c41 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -482,16 +482,17 @@ TRACE_EVENT(ext4_writepages, (unsigned long) __entry->writeback_index) ); -TRACE_EVENT(ext4_da_write_pages, - TP_PROTO(struct inode *inode, loff_t start_pos, +TRACE_EVENT(ext4_da_write_folios_start, + TP_PROTO(struct inode *inode, loff_t start_pos, loff_t next_pos, struct writeback_control *wbc), - TP_ARGS(inode, start_pos, wbc), + TP_ARGS(inode, start_pos, next_pos, wbc), TP_STRUCT__entry( __field( dev_t, dev ) __field( ino_t, ino ) __field( loff_t, start_pos ) + __field( loff_t, next_pos ) __field( long, nr_to_write ) __field( int, sync_mode ) ), @@ -500,16 +501,47 @@ TRACE_EVENT(ext4_da_write_pages, __entry->dev = inode->i_sb->s_dev; __entry->ino = inode->i_ino; __entry->start_pos = start_pos; + __entry->next_pos = next_pos; __entry->nr_to_write = wbc->nr_to_write; __entry->sync_mode = wbc->sync_mode; ), - TP_printk("dev %d,%d ino %lu start_pos 0x%llx nr_to_write %ld sync_mode %d", + TP_printk("dev %d,%d ino %lu start_pos 0x%llx next_pos 0x%llx nr_to_write %ld sync_mode %d", MAJOR(__entry->dev), MINOR(__entry->dev), - (unsigned long) __entry->ino, __entry->start_pos, + (unsigned long) __entry->ino, __entry->start_pos, __entry->next_pos, __entry->nr_to_write, __entry->sync_mode) ); +TRACE_EVENT(ext4_da_write_folios_end, + TP_PROTO(struct inode *inode, loff_t start_pos, loff_t next_pos, + struct writeback_control *wbc, int ret), + + TP_ARGS(inode, start_pos, next_pos, wbc, ret), + + TP_STRUCT__entry( + __field( dev_t, dev ) + __field( ino_t, ino ) + __field( loff_t, start_pos ) + __field( loff_t, next_pos ) + __field( long, nr_to_write ) + __field( int, ret ) + ), + + TP_fast_assign( + __entry->dev = inode->i_sb->s_dev; + __entry->ino = inode->i_ino; + __entry->start_pos = start_pos; + __entry->next_pos = next_pos; + __entry->nr_to_write = wbc->nr_to_write; + __entry->ret = ret; + ), + + TP_printk("dev %d,%d ino %lu start_pos 0x%llx next_pos 0x%llx nr_to_write %ld ret %d", + MAJOR(__entry->dev), MINOR(__entry->dev), + (unsigned long) __entry->ino, __entry->start_pos, __entry->next_pos, + __entry->nr_to_write, __entry->ret) +); + TRACE_EVENT(ext4_da_write_pages_extent, TP_PROTO(struct inode *inode, struct ext4_map_blocks *map), -- 2.46.1