On 22/12/02 07:39PM, Jan Kara wrote: > Hello, > > this patch series modifies ext4 so that we stop using ext4_writepage() for > writeout of ordered data during transaction commit (through > generic_writepages() from jbd2_journal_submit_inode_data_buffers()). Instead we > directly call ext4_writepages() from the > ext4_journal_submit_inode_data_buffers(). This is part of Christoph's effort > to get rid of the .writepage() callback in all filesystems. > > I have also modified ext4_writepages() to use write_cache_pages() instead of > generic_writepages() so now we don't expose .writepage hook at all. We still > keep ext4_writepage() as a callback for write_cache_pages(). We should refactor > that path as well and get rid of ext4_writepage() completely but that is for a > separate cleanup. Also note that jbd2 still uses generic_writepages() in its > jbd2_journal_submit_inode_data_buffers() helper because it is still used from > OCFS2. Again, something to be dealt with in a separate patchset. > > Changes since v1: > * Added Reviewed-by tags from Ritesh > * Added patch to get rid of generic_writepages() in ext4_writepages() > * Added patch to get rid of .writepage hook Oh! And what about the WARN_ON_ONCE in ext4_writepages() while loop, which we were discussing here [1]. Do you think that will help in catching anything nasty? [1]: https://lore.kernel.org/linux-ext4/20221201115500.kbxtteft3v4pzqqx@quack3/T/#mcf7b6cc301062e52a3600194b03a9fd872ba52c5 One thing I guess I missed in my previous review is the fast commit path. In my overnight testing of previous patch series I observed this warning. WARNING: CPU: 1 PID: 1746936 at fs/ext4/inode.c:1994 ext4_writepage+0x4e6/0x5e0 RIP: 0010:ext4_writepage+0x4e6/0x5e0 Call Trace: <TASK> __writepage+0x17/0x70 write_cache_pages+0x166/0x3c0 ? dirty_background_bytes_handler+0x30/0x30 ? finish_task_switch.isra.0+0x8e/0x260 ? _raw_spin_lock_irqsave+0x19/0x50 ? finish_wait+0x34/0x70 ? _raw_spin_unlock_irqrestore+0x1e/0x40 generic_writepages+0x4f/0x80 jbd2_journal_submit_inode_data_buffers+0x64/0x90 ext4_fc_commit+0x2e0/0x830 ? file_check_and_advance_wb_err+0x2e/0xd0 ? preempt_count_add+0x70/0xa0 ext4_sync_file+0x15c/0x380 __do_sys_msync+0x1c1/0x2a0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -ritesh > > Honza > Previous versions: > Link: http://lore.kernel.org/r/20221130162435.2324-1-jack@xxxxxxx # v1
