From: Chris Mason reiserfs_invalidatepage will refuse to free pages if they have been logged in data=journal mode, or were pinned down by a data=ordered operation. For data=journal, this is fairly easy to trigger just with fsx-linux, and it results in a large number of pages hanging around on the LRUs with page->mapping == NULL. Calling try_to_free_buffers when reiserfs decides it is done with the page allows it to be freed earlier, and with much less VM thrashing. Lock ordering rules mean that reiserfs can't call lock_page when it is releasing the buffers, so TestSetPageLocked is used instead. Contention on these pages should be rare, so it should be sufficient most of the time. Signed-off-by: Chris Mason Cc: "Vladimir V. Saveliev" Cc: Jeff Mahoney Signed-off-by: Andrew Morton --- fs/reiserfs/journal.c | 42 ++++++++++++++++++++++++++++++---------- 1 file changed, 32 insertions(+), 10 deletions(-) diff -puN fs/reiserfs/journal.c~try-to-reap-reiserfs-pages-left-around-by-invalidatepage fs/reiserfs/journal.c --- a/fs/reiserfs/journal.c~try-to-reap-reiserfs-pages-left-around-by-invalidatepage +++ a/fs/reiserfs/journal.c @@ -615,6 +615,31 @@ static int journal_list_still_alive(stru return 0; } +/* + * If page->mapping was null, we failed to truncate this page for + * some reason. Most likely because it was truncated after being + * logged via data=journal. + * + * This does a check to see if the buffer belongs to one of these + * lost pages before doing the final put_bh. If page->mapping was + * null, it tries to free buffers on the page, which should make the + * final page_cache_release drop the page from the lru. + */ +static void release_buffer_page(struct buffer_head *bh) +{ + struct page *page = bh->b_page; + if (!page->mapping && !TestSetPageLocked(page)) { + page_cache_get(page); + put_bh(bh); + if (!page->mapping) + try_to_free_buffers(page); + unlock_page(page); + page_cache_release(page); + } else { + put_bh(bh); + } +} + static void reiserfs_end_buffer_io_sync(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; @@ -628,8 +653,9 @@ static void reiserfs_end_buffer_io_sync( set_buffer_uptodate(bh); else clear_buffer_uptodate(bh); + unlock_buffer(bh); - put_bh(bh); + release_buffer_page(bh); } static void reiserfs_end_ordered_io(struct buffer_head *bh, int uptodate) @@ -1547,9 +1573,10 @@ static int flush_journal_list(struct sup BUG_ON(!test_clear_buffer_journal_dirty (cn->bh)); - /* undo the inc from journal_mark_dirty */ + /* drop one ref for us */ put_bh(cn->bh); - brelse(cn->bh); + /* drop one ref for journal_mark_dirty */ + release_buffer_page(cn->bh); } cn = cn->next; } @@ -3709,13 +3736,8 @@ int journal_mark_freed(struct reiserfs_t } } - if (bh) { - put_bh(bh); /* get_hash grabs the buffer */ - if (atomic_read(&(bh->b_count)) < 0) { - reiserfs_warning(p_s_sb, - "journal-2165: bh->b_count < 0"); - } - } + if (bh) + release_buffer_page(bh); /* get_hash grabs the buffer */ return 0; } _