nfs: stat(2) fails during cthon04 basic test5 on NFSv4.0

When running the Connectathon basic tests against a Solaris NFS
server over NFSv4.0, test5 reports that stat(2) returns a file size
of zero instead of 1MB.

On success, nfs_commit_inode() can return a positive result; see
other call sites such as nfs_file_fsync_commit() and
nfs_commit_unstable_pages().

The call site recently added in nfs_wb_all() does not prevent that
positive return value from leaking to its callers. If it leaks
through nfs_sync_inode() back to nfs_getattr(), that causes stat(2)
to return a positive return value to user space while also not
filling in the passed-in struct stat.

Additional clean up: the new logic in nfs_wb_all() is rewritten in
bfields-normal form.

Fixes: 5bb89b4702 ("NFSv4.1/pnfs: Separate out metadata . . .")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Chuck Lever 2015-05-06 18:26:58 -04:00 committed by Trond Myklebust
parent 030bbdbf4c
commit 6b19687563

View file

@ -1845,12 +1845,15 @@ int nfs_wb_all(struct inode *inode)
trace_nfs_writeback_inode_enter(inode);
ret = filemap_write_and_wait(inode->i_mapping);
if (!ret) {
ret = nfs_commit_inode(inode, FLUSH_SYNC);
if (!ret)
pnfs_sync_inode(inode, true);
}
if (ret)
goto out;
ret = nfs_commit_inode(inode, FLUSH_SYNC);
if (ret < 0)
goto out;
pnfs_sync_inode(inode, true);
ret = 0;
out:
trace_nfs_writeback_inode_exit(inode, ret);
return ret;
}