diff options
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 88203ae5b154..2a4507deb925 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1643,6 +1643,7 @@ struct mpage_da_data { */ struct ext4_map_blocks map; struct ext4_io_submit io_submit; /* IO submission data */ + unsigned int do_map:1; }; static void mpage_release_unused_pages(struct mpage_da_data *mpd, @@ -2179,6 +2180,9 @@ static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, /* First block in the extent? */ if (map->m_len == 0) { + /* We cannot map unless handle is started... */ + if (!mpd->do_map) + return false; map->m_lblk = lblk; map->m_len = 1; map->m_flags = bh->b_state & BH_FLAGS; @@ -2231,6 +2235,9 @@ static int mpage_process_page_bufs(struct mpage_da_data *mpd, /* Found extent to map? */ if (mpd->map.m_len) return 0; + /* Buffer needs mapping and handle is not started? */ + if (!mpd->do_map) + return 0; /* Everything mapped so far and we hit EOF */ break; } @@ -2747,6 +2754,29 @@ retry: tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page); done = false; blk_start_plug(&plug); + + /* + * First writeback pages that don't need mapping - we can avoid + * starting a transaction unnecessarily and also avoid being blocked + * in the block layer on device congestion while having transaction + * started. + */ + mpd.do_map = 0; + mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); + if (!mpd.io_submit.io_end) { + ret = -ENOMEM; + goto unplug; + } + ret = mpage_prepare_extent_to_map(&mpd); + /* Submit prepared bio */ + ext4_io_submit(&mpd.io_submit); + ext4_put_io_end_defer(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; + /* Unlock pages we didn't use */ + mpage_release_unused_pages(&mpd, false); + if (ret < 0) + goto unplug; + while (!done && mpd.first_page <= mpd.last_page) { /* For each extent of pages we use new io_end */ mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); @@ -2775,8 +2805,10 @@ retry: wbc->nr_to_write, inode->i_ino, ret); /* Release allocated io_end */ ext4_put_io_end(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; break; } + mpd.do_map = 1; trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc); ret = mpage_prepare_extent_to_map(&mpd); @@ -2807,6 +2839,7 @@ retry: if (!ext4_handle_valid(handle) || handle->h_sync == 0) { ext4_journal_stop(handle); handle = NULL; + mpd.do_map = 0; } /* Submit prepared bio */ ext4_io_submit(&mpd.io_submit); @@ -2824,6 +2857,7 @@ retry: ext4_journal_stop(handle); } else ext4_put_io_end(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; if (ret == -ENOSPC && sbi->s_journal) { /* @@ -2839,6 +2873,7 @@ retry: if (ret) break; } +unplug: blk_finish_plug(&plug); if (!ret && !cycled && wbc->nr_to_write > 0) { cycled = 1; |