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authorJing Xia <jing.xia@unisoc.com>2022-05-10 10:35:14 +0800
committerJan Kara <jack@suse.cz>2022-05-10 12:04:21 +0200
commit846a3351ddfe4a86eede4bb26a205c3f38ef84d3 (patch)
treefbf820bad4352c07bd24133d9e8bff82177a8475 /fs/fs-writeback.c
parentceaf69f8eadcafb323392be88e7a5248c415d423 (diff)
writeback: Avoid skipping inode writeback
We have run into an issue that a task gets stuck in balance_dirty_pages_ratelimited() when perform I/O stress testing. The reason we observed is that an I_DIRTY_PAGES inode with lots of dirty pages is in b_dirty_time list and standard background writeback cannot writeback the inode. After studing the relevant code, the following scenario may lead to the issue: task1 task2 ----- ----- fuse_flush write_inode_now //in b_dirty_time writeback_single_inode __writeback_single_inode fuse_write_end filemap_dirty_folio __xa_set_mark:PAGECACHE_TAG_DIRTY lock inode->i_lock if mapping tagged PAGECACHE_TAG_DIRTY inode->i_state |= I_DIRTY_PAGES unlock inode->i_lock __mark_inode_dirty:I_DIRTY_PAGES lock inode->i_lock -was dirty,inode stays in -b_dirty_time unlock inode->i_lock if(!(inode->i_state & I_DIRTY_All)) -not true,so nothing done This patch moves the dirty inode to b_dirty list when the inode currently is not queued in b_io or b_more_io list at the end of writeback_single_inode. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> CC: stable@vger.kernel.org Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") Signed-off-by: Jing Xia <jing.xia@unisoc.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220510023514.27399-1-jing.xia@unisoc.com
Diffstat (limited to 'fs/fs-writeback.c')
-rw-r--r--fs/fs-writeback.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 591fe9cf1659..1fae0196292a 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1712,6 +1712,10 @@ static int writeback_single_inode(struct inode *inode,
*/
if (!(inode->i_state & I_DIRTY_ALL))
inode_cgwb_move_to_attached(inode, wb);
+ else if (!(inode->i_state & I_SYNC_QUEUED) &&
+ (inode->i_state & I_DIRTY))
+ redirty_tail_locked(inode, wb);
+
spin_unlock(&wb->list_lock);
inode_sync_complete(inode);
out: