This is a note to let you know that I've just added the patch titled jbd2: Fix unreclaimed pages after truncate in data=journal mode to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: jbd2-fix-unreclaimed-pages-after-truncate-in-data-journal-mode.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bc23f0c8d7ccd8d924c4e70ce311288cb3e61ea8 Mon Sep 17 00:00:00 2001 From: Jan Kara <jack@xxxxxxx> Date: Tue, 24 Nov 2015 15:34:35 -0500 Subject: jbd2: Fix unreclaimed pages after truncate in data=journal mode From: Jan Kara <jack@xxxxxxx> commit bc23f0c8d7ccd8d924c4e70ce311288cb3e61ea8 upstream. Ted and Namjae have reported that truncated pages don't get timely reclaimed after being truncated in data=journal mode. The following test triggers the issue easily: for (i = 0; i < 1000; i++) { pwrite(fd, buf, 1024*1024, 0); fsync(fd); fsync(fd); ftruncate(fd, 0); } The reason is that journal_unmap_buffer() finds that truncated buffers are not journalled (jh->b_transaction == NULL), they are part of checkpoint list of a transaction (jh->b_cp_transaction != NULL) and have been already written out (!buffer_dirty(bh)). We clean such buffers but we leave them in the checkpoint list. Since checkpoint transaction holds a reference to the journal head, these buffers cannot be released until the checkpoint transaction is cleaned up. And at that point we don't call release_buffer_page() anymore so pages detached from mapping are lingering in the system waiting for reclaim to find them and free them. Fix the problem by removing buffers from transaction checkpoint lists when journal_unmap_buffer() finds out they don't have to be there anymore. Reported-and-tested-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Fixes: de1b794130b130e77ffa975bb58cb843744f9ae5 Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/jbd2/transaction.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1936,6 +1936,7 @@ static int journal_unmap_buffer(journal_ if (!buffer_dirty(bh)) { /* bdflush has written it. We can drop it now */ + __jbd2_journal_remove_checkpoint(jh); goto zap_buffer; } @@ -1965,6 +1966,7 @@ static int journal_unmap_buffer(journal_ /* The orphan record's transaction has * committed. We can cleanse this buffer */ clear_buffer_jbddirty(bh); + __jbd2_journal_remove_checkpoint(jh); goto zap_buffer; } } Patches currently in stable-queue which might be from jack@xxxxxxx are queue-3.10/jbd2-fix-unreclaimed-pages-after-truncate-in-data-journal-mode.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html