On 05/28, Chao Yu wrote: > On 2020/5/28 10:45, Chao Yu wrote: > > On 2020/5/27 10:20, Sahitya Tummala wrote: > >> In case a compressed file is getting overwritten, the current retry > >> logic doesn't include the current page to be retried now as it sets > >> the new start index as 0 and new end index as writeback_index - 1. > >> This causes the corresponding cluster to be uncompressed and written > >> as normal pages without compression. Fix this by allowing writeback to > >> be retried for the current page as well (in case of compressed page > >> getting retried due to index mismatch with cluster index). So that > >> this cluster can be written compressed in case of overwrite. > >> > >> Signed-off-by: Sahitya Tummala <stumm...@codeaurora.org> > >> --- > >> fs/f2fs/data.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > >> index 4af5fcd..bfd1df4 100644 > >> --- a/fs/f2fs/data.c > >> +++ b/fs/f2fs/data.c > >> @@ -3024,7 +3024,7 @@ static int f2fs_write_cache_pages(struct > >> address_space *mapping, > >> if ((!cycled && !done) || retry) { > > > > IMO, we add retry logic in wrong place, you can see that cycled value is > > zero only if wbc->range_cyclic is true, in that case writeback_index is > > valid. > > > > However if retry is true and wbc->range_cyclic is false, then > > writeback_index > > would be uninitialized variable. > > > > Thoughts? > > > > Thanks, > > > >> cycled = 1; > >> index = 0; > >> - end = writeback_index - 1; > > BTW, I notice that range_cyclic writeback flow was refactored in below commit, > and skeleton of f2fs.writepages was copied from > mm/page-writeback.c::write_cache_pages(), > I guess we need follow that change. > > 64081362e8ff ("mm/page-writeback.c: fix range_cyclic writeback vs writepages > deadlock")
Is that something like this? --- fs/f2fs/data.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 48a622b95b76e..28fcdf0d4dcb9 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2861,7 +2861,6 @@ static int f2fs_write_cache_pages(struct address_space *mapping, pgoff_t index; pgoff_t end; /* Inclusive */ pgoff_t done_index; - int cycled; int range_whole = 0; xa_mark_t tag; int nwritten = 0; @@ -2879,17 +2878,12 @@ static int f2fs_write_cache_pages(struct address_space *mapping, if (wbc->range_cyclic) { writeback_index = mapping->writeback_index; /* prev offset */ index = writeback_index; - if (index == 0) - cycled = 1; - else - cycled = 0; end = -1; } else { index = wbc->range_start >> PAGE_SHIFT; end = wbc->range_end >> PAGE_SHIFT; if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; - cycled = 1; /* ignore range_cyclic tests */ } if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) tag = PAGECACHE_TAG_TOWRITE; @@ -3054,10 +3048,9 @@ static int f2fs_write_cache_pages(struct address_space *mapping, } } #endif - if ((!cycled && !done) || retry) { - cycled = 1; + if (retry) { index = 0; - end = writeback_index - 1; + end = -1; goto retry; } if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) -- 2.27.0.rc0.183.gde8f92d652-goog _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel