From a08a8cd375db9769588257e7782f6b6b68561b88 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 26 Feb 2015 17:36:09 -0500 Subject: NFS: Add attribute update barriers to NFS writebacks Ensure that other operations that race with our write RPC calls cannot revert the file size updates that were made on the server. Signed-off-by: Trond Myklebust Tested-by: Chuck Lever --- fs/nfs/write.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 595d81e354d1..849ed784d6ac 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1377,6 +1377,36 @@ static int nfs_should_remove_suid(const struct inode *inode) return 0; } +static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr, + struct nfs_fattr *fattr) +{ + struct nfs_pgio_args *argp = &hdr->args; + struct nfs_pgio_res *resp = &hdr->res; + + if (!(fattr->valid & NFS_ATTR_FATTR_SIZE)) + return; + if (argp->offset + resp->count != fattr->size) + return; + if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) + return; + /* Set attribute barrier */ + nfs_fattr_set_barrier(fattr); +} + +void nfs_writeback_update_inode(struct nfs_pgio_header *hdr) +{ + struct nfs_fattr *fattr = hdr->res.fattr; + struct inode *inode = hdr->inode; + + if (fattr == NULL) + return; + spin_lock(&inode->i_lock); + nfs_writeback_check_extend(hdr, fattr); + nfs_post_op_update_inode_force_wcc_locked(inode, fattr); + spin_unlock(&inode->i_lock); +} +EXPORT_SYMBOL_GPL(nfs_writeback_update_inode); + /* * This function is called when the WRITE call is complete. */ -- cgit v1.2.3