diff options
| author | Dave Chinner <dchinner@redhat.com> | 2010-06-09 10:37:18 +1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-06-08 18:12:44 -0700 |
| commit | 0b5649278e39a068aaf91399941bab1b4a4a3cc2 (patch) | |
| tree | 3fd2c782385137f5b135c07149de772e207fdaf8 /include | |
| parent | 8d7458daea2a6809d32418bf489b949d23de99ea (diff) | |
writeback: pay attention to wbc->nr_to_write in write_cache_pages
If a filesystem writes more than one page in ->writepage, write_cache_pages
fails to notice this and continues to attempt writeback when wbc->nr_to_write
has gone negative - this trace was captured from XFS:
wbc_writeback_start: towrt=1024
wbc_writepage: towrt=1024
wbc_writepage: towrt=0
wbc_writepage: towrt=-1
wbc_writepage: towrt=-5
wbc_writepage: towrt=-21
wbc_writepage: towrt=-85
This has adverse effects on filesystem writeback behaviour. write_cache_pages()
needs to terminate after a certain number of pages are written, not after a
certain number of calls to ->writepage are made. This is a regression
introduced by 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 ("vfs: Add
no_nrwrite_index_update writeback control flag"), but cannot be reverted
directly due to subsequent bug fixes that have gone in on top of it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/writeback.h | 9 | ||||
| -rw-r--r-- | include/trace/events/ext4.h | 5 |
2 files changed, 1 insertions, 13 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index f64134653a8..d63ef8f9609 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -56,15 +56,6 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned more_io:1; /* more io to be dispatched */ - /* - * write_cache_pages() won't update wbc->nr_to_write and - * mapping->writeback_index if no_nrwrite_index_update - * is set. write_cache_pages() may write more than we - * requested and we want to make sure nr_to_write and - * writeback_index are updated in a consistent manner - * so we use a single control to update them - */ - unsigned no_nrwrite_index_update:1; }; /* diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index f5b1ba90e95..f3865c7b416 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -306,7 +306,6 @@ TRACE_EVENT(ext4_da_writepages_result, __field( int, pages_written ) __field( long, pages_skipped ) __field( char, more_io ) - __field( char, no_nrwrite_index_update ) __field( pgoff_t, writeback_index ) ), @@ -317,16 +316,14 @@ TRACE_EVENT(ext4_da_writepages_result, __entry->pages_written = pages_written; __entry->pages_skipped = wbc->pages_skipped; __entry->more_io = wbc->more_io; - __entry->no_nrwrite_index_update = wbc->no_nrwrite_index_update; __entry->writeback_index = inode->i_mapping->writeback_index; ), - TP_printk("dev %s ino %lu ret %d pages_written %d pages_skipped %ld more_io %d no_nrwrite_index_update %d writeback_index %lu", + TP_printk("dev %s ino %lu ret %d pages_written %d pages_skipped %ld more_io %d writeback_index %lu", jbd2_dev_to_name(__entry->dev), (unsigned long) __entry->ino, __entry->ret, __entry->pages_written, __entry->pages_skipped, __entry->more_io, - __entry->no_nrwrite_index_update, (unsigned long) __entry->writeback_index) ); |