From a9ab5e840669b19aca2974e2c771a77df2876434 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Nov 2013 08:50:34 -0800 Subject: [PATCH] nfs: page cache invalidation for dio Make sure to properly invalidate the pagecache before performing direct I/O, so that no stale pages are left around. This matches what the generic direct I/O code does. Also take the i_mutex over the direct write submission to avoid the lifelock vs truncate waiting for i_dio_count to decrease, and to avoid having the pagecache easily repopulated while direct I/O is in progrss. Again matching the generic direct I/O code. Signed-off-by: Christoph Hellwig Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 85e4e4b..b8797ae 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -939,9 +939,12 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, struct inode *inode = mapping->host; struct nfs_direct_req *dreq; struct nfs_lock_context *l_ctx; + loff_t end; size_t count; count = iov_length(iov, nr_segs); + end = (pos + count - 1) >> PAGE_CACHE_SHIFT; + nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n", @@ -958,16 +961,25 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, if (!count) goto out; + mutex_lock(&inode->i_mutex); + result = nfs_sync_mapping(mapping); if (result) - goto out; + goto out_unlock; + + if (mapping->nrpages) { + result = invalidate_inode_pages2_range(mapping, + pos >> PAGE_CACHE_SHIFT, end); + if (result) + goto out_unlock; + } task_io_account_write(count); result = -ENOMEM; dreq = nfs_direct_req_alloc(); if (!dreq) - goto out; + goto out_unlock; dreq->inode = inode; dreq->bytes_left = count; @@ -982,6 +994,14 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, dreq->iocb = iocb; result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio); + + if (mapping->nrpages) { + invalidate_inode_pages2_range(mapping, + pos >> PAGE_CACHE_SHIFT, end); + } + + mutex_unlock(&inode->i_mutex); + if (!result) { result = nfs_direct_wait(dreq); if (result > 0) { @@ -994,8 +1014,13 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, spin_unlock(&inode->i_lock); } } + nfs_direct_req_release(dreq); + return result; + out_release: nfs_direct_req_release(dreq); +out_unlock: + mutex_unlock(&inode->i_mutex); out: return result; } -- 2.7.4