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From:   Zheng Bin <zhengbin13@huawei.com>
To:     <trond.myklebust@hammerspace.com>, <anna.schumaker@netapp.com>,
        <linux-nfs@vger.kernel.org>
CC:     <yi.zhang@huawei.com>, <zhangxiaoxu5@huawei.com>,
        <zhengbin13@huawei.com>
Subject: [PATCH] nfs: set invalid blocks after NFSv4 writes
Date:   Wed, 20 May 2020 09:30:36 +0800
Message-ID: <20200520013037.113612-1-zhengbin13@huawei.com>
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Sender: linux-nfs-owner@vger.kernel.org
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Use the following command to test nfsv4(size of file1M is 1MB):
mount -t nfs -o vers=4.0,actimeo=60 127.0.0.1/dir1 /mnt
cp file1M /mnt
du -h /mnt/file1M  -->0 within 60s, then 1M

When write is done(cp file1M /mnt), will call this:
nfs_writeback_done
  nfs4_write_done
    nfs4_write_done_cb
      nfs_writeback_update_inode
        nfs_post_op_update_inode_force_wcc_locked(change, ctime, mtime
nfs_post_op_update_inode_force_wcc_locked
   nfs_set_cache_invalid
   nfs_refresh_inode_locked
     nfs_update_inode

nfsd write response contains change, ctime, mtime, the flag will be
clear after nfs_update_inode. Howerver, write response does not contain
space_used, previous open response contains space_used whose value is 0,
so inode->i_blocks is still 0.

nfs_getattr  -->called by "du -h"
  do_update |= force_sync || nfs_attribute_cache_expired -->false in 60s
  cache_validity = READ_ONCE(NFS_I(inode)->cache_validity)
  do_update |= cache_validity & (NFS_INO_INVALID_ATTR    -->false
  if (do_update) {
        __nfs_revalidate_inode
  }

Within 60s, does not send getattr request to nfsd, thus "du -h /mnt/file1M"
is 0.

Add a NFS_INO_INVALID_BLOCKS flag, set it when nfsv4 write is done.

Fixes: 16e143751727 ("NFS: More fine grained attribute tracking")
Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
---
 fs/nfs/inode.c         | 9 +++++++--
 include/linux/nfs_fs.h | 6 ++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index b9d0921cb4fe..2d743e42fee1 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1764,7 +1764,8 @@ int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fa
 	status = nfs_post_op_update_inode_locked(inode, fattr,
 			NFS_INO_INVALID_CHANGE
 			| NFS_INO_INVALID_CTIME
-			| NFS_INO_INVALID_MTIME);
+			| NFS_INO_INVALID_MTIME
+			| NFS_INO_INVALID_BLOCKS);
 	return status;
 }

@@ -2033,8 +2034,12 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
 	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
 		inode->i_blocks = fattr->du.nfs2.blocks;
-	else
+	else {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_BLOCKS
+				| NFS_INO_REVAL_FORCED);
 		cache_revalidated = false;
+	}

 	/* Update attrtimeo value if we're out of the unstable period */
 	if (attr_changed) {
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 73eda45f1cfd..77efdca12cab 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -227,14 +227,16 @@ struct nfs4_copy_state {
 #define NFS_INO_INVALID_CTIME	BIT(9)		/* cached ctime is invalid */
 #define NFS_INO_INVALID_MTIME	BIT(10)		/* cached mtime is invalid */
 #define NFS_INO_INVALID_SIZE	BIT(11)		/* cached size is invalid */
-#define NFS_INO_INVALID_OTHER	BIT(12)		/* other attrs are invalid */
+#define NFS_INO_INVALID_BLOCKS	BIT(12)         /* cached blocks are invalid */
+#define NFS_INO_INVALID_OTHER	BIT(13)		/* other attrs are invalid */
 #define NFS_INO_DATA_INVAL_DEFER	\
-				BIT(13)		/* Deferred cache invalidation */
+				BIT(14)		/* Deferred cache invalidation */

 #define NFS_INO_INVALID_ATTR	(NFS_INO_INVALID_CHANGE \
 		| NFS_INO_INVALID_CTIME \
 		| NFS_INO_INVALID_MTIME \
 		| NFS_INO_INVALID_SIZE \
+		| NFS_INO_INVALID_BLOCKS \
 		| NFS_INO_INVALID_OTHER)	/* inode metadata is invalid */

 /*
--
2.26.0.106.g9fadedd