From: Zhang Yi <yi.zhang@xxxxxxxxxx> Changes since v1: - Make the write-back process supports writing a partial folio if it exits the mapping loop prematurely due to insufficient sapce or journal credits, it also fix the potential stale data and inconsistency issues. - Fix the same issue regarding the allocation of blocks in ext4_write_begin() and ext4_page_mkwrite() when delalloc is not enabled. This series addresses the issue that Jan pointed out regarding large folios support for ext4[1]. The problem is that the credits calculation may insufficient in ext4_meta_trans_blocks() when allocating blocks during write back a sufficiently large and discontinuous folio, it doesn't involve the credits for updating bitmap and group descriptor block. However, if we fix this issue, it may lead to significant overestimation on the some filesystems with a lot of block groups. The solution involves first ensure that the current journal transaction has enough credits when we mapping an extent during allocating blocks. Then if the credits reach the upper limit, exit the current mapping loop, submit the partial folio and restart a new transaction. Finally, fix the wrong credits calculation in ext4_meta_trans_blocks(). Please see the following patches for details. [1] https://lore.kernel.org/linux-ext4/ht54j6bvjmiqt62xmcveqlo7bmrunqs4ji7wikfteftdjijzek@7tz5gpejaoen/ Thanks, Yi. Zhang Yi (6): ext4: move the calculation of wbc->nr_to_write to mpage_folio_done() ext4: fix stale data if it bail out of the extents mapping loop ext4: restart handle if credits are insufficient during allocating blocks ext4: correct the reserved credits for extent conversion ext4/jbd2: reintroduce jbd2_journal_blocks_per_page() ext4: fix insufficient credits calculation in ext4_meta_trans_blocks() fs/ext4/ext4_jbd2.h | 7 +++ fs/ext4/inode.c | 118 ++++++++++++++++++++++++++++++++++++------- fs/jbd2/journal.c | 6 +++ include/linux/jbd2.h | 1 + 4 files changed, 113 insertions(+), 19 deletions(-) -- 2.46.1
