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Date:   Thu, 30 Apr 2020 10:05:45 -0400
From:   "J. Bruce Fields" <bfields@fieldses.org>
To:     Achilles Gaikwad <agaikwad@redhat.com>
Cc:     linux-nfs@vger.kernel.org, steved@redhat.com, kdsouza@redhat.com
Subject: Re: [PATCH] nfs-utils: add new tool nfsd4-show to parse output from
 proc files
Message-ID: <20200430140545.GA28617@fieldses.org>
References: <20200428165142.GA1392654@nevermore.foobar.lan>
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Just one thing that jumped out at me:

On Tue, Apr 28, 2020 at 10:21:42PM +0530, Achilles Gaikwad wrote:
> +# this function converts the info file to a dictionary format, sorta. :)
> +def file_to_dict(path):
> +    client_info = {}
> +    with open(path) as f:
> +        for line in f:
> +            try:
> +                (key, val) = line.split(':')

A colon could appear in a string and this would give the wrong results.

These files are supposed to be legal json.  I think we want to use
python's builtin "json" module rather than try to parse them on our own.

--b.

> +                client_info[key] = val
> +    # FIXME: There has to be a better way of converting tscrews he info file to a dictionary.
> +            except ValueError:
> +                try:
> +                    (key, val) = line.split()
> +                    client_info[key] = val
> +                except:
> +                    pass
> +    return client_info
> +
> +# this functino gets the paths from /proc/fs/nfsd/clients/
> +# returns a list of paths for each client which has nfs-share mounted.
> +def getpaths():
> +    path = []
> +    try:
> +        dirs = os.listdir('/proc/fs/nfsd/clients/')
> +    except OSError as reason:
> +        exit('%s' % reason)
> +    if len(dirs) !=0:
> +	    for i in dirs:
> +		    path.append('/proc/fs/nfsd/clients/' + i + '/states')
> +	    return (path)
> +    else:
> +	    exit('Nothing to process')
> +
> +# A single function to rule them all, in this function we gather all the data
> +# from already populated data_list and client_info.
> +def printer(data_list, argument):
> +    client_info_path = data_list.pop()
> +    client_info = file_to_dict(client_info_path)
> +    for i in data_list:
> +        for key in i:
> +            inode = i[key]['superblock'].split(':')[-1]
> +            # get the ip address from client_info as 'address:' note the extra
> +            # ':' as a suffix to address. If there is a better way to convert
> +            # the file to dictionary, please change the following value too.
> +            client_ip = client_info['address:']
> +            # The ip address is quoted, so we dequote it.
> +            client_ip = client_ip[1:-1]
> +            try:
> +                # if the nfs-server reboots while the nfs-client holds the files open,
> +                # the nfs-server would print the filename as '/'. For such instaces we
> +                # print the output as disconnected dentry instead of '/'.
> +                if(i[key]['filename']=='/'):
> +                    fname = 'disconnected dentry'
> +                else:
> +                    fname = i[key]['filename'].split('/')[-1]
> +            except KeyError:
> +                # for older kernels which do not have the fname patch in kernel, they
> +                # won't be able to see the fname field. Therefore post it as N/A.
> +                fname = "N/A"
> +            otype = i[key]['type']
> +            try:
> +                access = i[key]['access']
> +            except:
> +                access = ''
> +            try:
> +                deny = i[key]['deny']
> +            except:
> +                deny = ''
> +            hostname = client_info['name'].split()[-1].split('"')[0]
> +            hostname =  hostname.split('.')[0]
> +            otype = i[key]['type']
> +            # if the hostname is too long, it messes up with the output being in columns,
> +            # therefore we truncate the hostname followed by two '..' as suffix.
> +            if len(hostname) > 20:
> +                hostname = hostname[0:20] + '..'
> +            clientid = client_info['clientid'].strip()
> +            minorversion = client_info['minor version'].rstrip().rsplit()[0]
> +            # since some fields do not have deny column, we drop those if -t is either
> +            # layout or lock.
> +            drop = ['layout', 'lock']
> +
> +            # Printing the output this way instead of a single string which is concatenated
> +            # this makes it better to quickly add more columns in future.
> +            if(otype == argument.type or  argument.type == 'all'):
> +                print('%-13s' %inode, end='| ')
> +                print('%-7s' %otype, end='| ')
> +                if (argument.type not in drop):
> +                    print('%-7s' %access, end='| ')
> +                if (argument.type not in drop and argument.type !='deleg'):
> +                    print('%-5s' %deny, end='| ')
> +                if (argument.hostname == True):
> +                    print('%-22s' %hostname, end='| ')
> +                else:
> +                   print('%-22s' %client_ip, end='| ')
> +                if (argument.clientinfo == True) :
> +                    print('%-20s' %clientid, end='| ')
> +                    print('4.%-3s' %minorversion, end='| ')
> +                print(fname)
> +
> +def opener(path):
> +    try:
> +        with open(path, 'r') as nfsdata:
> +            data = yaml.load(nfsdata, Loader = yaml.BaseLoader)
> +            if data is not None:
> +                clientinfo = path.rsplit('/', 1)[0] + '/info'
> +                data.append(clientinfo)
> +                return data
> +
> +    except OSError as reason:
> +        print('%s' % reason)
> +
> +def print_cols(argument):
> +    title_inode = 'Inode number'
> +    title_otype = 'Type'
> +    title_access = 'Access'
> +    title_deny = 'Deny'
> +    title_fname = 'Filename'
> +    title_clientID = 'Client ID'
> +    title_hostname = 'Hostname'
> +    title_ip = 'ip address'
> +    title_nfsvers = 'vers'
> +
> +    drop = ['lock', 'layout']
> +    print(BBOLD, end='')
> +    print('%-13s' %title_inode, end='| ')
> +    print('%-7s' %title_otype, end='| ')
> +    if (argument.type not in drop):
> +        print('%-7s' %title_access, end='| ')
> +    if (argument.type not in drop and argument.type !='deleg'):
> +        print('%-5s' %title_deny, end='| ')
> +    if (argument.hostname == True):
> +        print('%-22s' %title_hostname, end='| ')
> +    else:
> +        print('%-22s' %title_ip, end='| ')
> +    if (argument.clientinfo == True):
> +        print('%-20s' %title_clientID, end='| ')
> +        print('%-5s' %title_nfsvers, end='| ')
> +    print(title_fname, end='')
> +    print(ENDC)
> +
> +def nfsd4_show():
> +
> +    parser = argparse.ArgumentParser(description = 'Parse the nfsd states and clientinfo files.')
> +    parser.add_argument('-t', '--type', metavar = 'type', type = str, choices = ['open',
> +        'deleg', 'lock', 'layout', 'all'],
> +        default = 'all',
> +        help = 'Input the type that you want to be printed: open, lock, deleg, layout, all')
> +    parser.add_argument('--clientinfo', action = 'store_true',
> +        help = 'output clients information, --hostname is implied.')
> +    parser.add_argument('--hostname', action = 'store_true',
> +        help = 'print hostname of client instead of its ip address. Longer hostnames are truncated.')
> +    parser.add_argument('-q', '--quiet', action = 'store_true',
> +        help = 'don\'t print the header information')
> +
> +    args = parser.parse_args()
> +    paths = getpaths()
> +    p = mp.Pool(mp.cpu_count(), init_worker)
> +    try:
> +        result = p.map(opener, paths)
> +        p.close()
> +        p.join()
> +        if len(result) !=0 and not args.quiet and result[0] is not None:
> +            print_cols(args)
> +
> +        for i in result:
> +            if i is not None:
> +                printer(i, args)
> +
> +    except KeyboardInterrupt:
> +        print('Caught KeyboardInterrupt, terminating workers')
> +        p.terminate()
> +        p.join()
> +
> +if __name__ == "__main__":
> +    nfsd4_show()
> -- 
> 2.25.4