ext4 journal commit callbacks access jbd2_inode fields such as i_transaction and i_dirty_start/end without holding journal->j_list_lock. Use READ_ONCE() for these reads to match the lockless access pattern. Convert the dirty range from PAGE_SIZE units back to byte offsets before passing it to writeback. Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Li Chen --- Changes since v1: - Convert the jinode dirty range from PAGE_SIZE units (pgoff_t) back to byte offsets before passing it to writeback. fs/ext4/inode.c | 12 ++++++++++-- fs/ext4/super.c | 19 ++++++++++++++----- 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d99296d7315f..5ec60580a2d0 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3033,11 +3033,19 @@ static int ext4_writepages(struct address_space *mapping, int ext4_normal_submit_inode_data_buffers(struct jbd2_inode *jinode) { + pgoff_t dirty_start = READ_ONCE(jinode->i_dirty_start); + pgoff_t dirty_end = READ_ONCE(jinode->i_dirty_end); + loff_t range_start, range_end; + + if (dirty_end == JBD2_INODE_DIRTY_RANGE_NONE) + return 0; + range_start = (loff_t)dirty_start << PAGE_SHIFT; + range_end = ((loff_t)dirty_end << PAGE_SHIFT) + PAGE_SIZE - 1; struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, - .range_start = jinode->i_dirty_start, - .range_end = jinode->i_dirty_end, + .range_start = range_start, + .range_end = range_end, }; struct mpage_da_data mpd = { .inode = jinode->i_vfs_inode, diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 69eb63dde983..27062c8ad60a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -521,6 +521,7 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, { struct buffer_head *bh, *head; struct journal_head *jh; + transaction_t *trans = READ_ONCE(jinode->i_transaction); bh = head = folio_buffers(folio); do { @@ -539,7 +540,7 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, */ jh = bh2jh(bh); if (buffer_dirty(bh) || - (jh && (jh->b_transaction != jinode->i_transaction || + (jh && (jh->b_transaction != trans || jh->b_next_transaction))) return true; } while ((bh = bh->b_this_page) != head); @@ -550,12 +551,20 @@ static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode, static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode) { struct address_space *mapping = jinode->i_vfs_inode->i_mapping; + pgoff_t dirty_start = READ_ONCE(jinode->i_dirty_start); + pgoff_t dirty_end = READ_ONCE(jinode->i_dirty_end); + loff_t range_start, range_end; + + if (dirty_end == JBD2_INODE_DIRTY_RANGE_NONE) + return 0; + range_start = (loff_t)dirty_start << PAGE_SHIFT; + range_end = ((loff_t)dirty_end << PAGE_SHIFT) + PAGE_SIZE - 1; struct writeback_control wbc = { - .sync_mode = WB_SYNC_ALL, + .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, - .range_start = jinode->i_dirty_start, - .range_end = jinode->i_dirty_end, - }; + .range_start = range_start, + .range_end = range_end, + }; struct folio *folio = NULL; int error; -- 2.52.0