The current test in nfs_commit_unstable_pages does not handle the edge condition properly. When ncommit == 0, then that likely means that the kernel doesn't need to do anything more for the inode. The current test though will return true in that case, and the inode will end up being marked dirty. Fix this by not re-marking the inode dirty when ncommit == 0. Mike noticed this problem initially in RHEL5 (2.6.18-based kernel) which has a backported version of 420e3646. The inode cache there was growing very large, but calling sync() would essentially "fix" the problem. What I'm not clear on is how big a problem this is in mainline kernels as the writeback code there is very different. I think this basically means that the inode will remain dirty until there's a WB_SYNC_ALL flush. Either way, it seems incorrect to mark the inode dirty in this case. Also, another question I have here -- shouldn't we be holding the i_lock when doing this check? Reported-by: Mike McLean <mikem@xxxxxxxxxx> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- fs/nfs/write.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 17e20e4..6395e98 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1557,7 +1557,7 @@ static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_contr /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ - if (nfsi->ncommit <= (nfsi->npages >> 1)) + if (nfsi->ncommit && nfsi->ncommit <= (nfsi->npages >> 1)) goto out_mark_dirty; /* don't wait for the COMMIT response */ -- 1.7.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
