Re: [V9fs-developer] [PATCH 2/2] [9p] Introduce client side TFSYNC/RFSYNC for dotl.

["Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>]

On 9/27/2010 5:59 AM, Eric Van Hensbergen wrote:
> Remind me again why we need this?  Don't blank twstats provide the
> same functionality?

WSTAT is a dotu operation, and we are overloading it to accomplish the sync.
I think it is good idea to avoid overloading in dotl and especially if it is 
happening
through dotu protocol. Also, we are trying to get 1-to-1 correspondence (where 
ever is possible)
between Linux VFS and dotl.

Thanks,
JV

>           -eric
>
>
> On Fri, Sep 24, 2010 at 8:04 PM, Venkateswararao Jujjuri (JV)
> <jvrao@linux.vnet.ibm.com>  wrote:
>> SYNOPSIS
>>     size[4] Tfsync tag[2] fid[4]
>>
>>     size[4] Rfsync tag[2]
>>
>> DESCRIPTION
>>
>> The Tfsync transaction transfers ("flushes") all modified in-core data of
>> file identified by fid to the disk device (or other  permanent  storage
>> device)  where that  file  resides.
>>
>> Signed-off-by: Venkateswararao Jujjuri<jvrao@linux.vnet.ibm.com>
>> ---
>>   fs/9p/vfs_file.c        |   18 ++++++++++++++++--
>>   include/net/9p/9p.h     |    2 ++
>>   include/net/9p/client.h |    1 +
>>   net/9p/client.c         |   25 +++++++++++++++++++++++++
>>   4 files changed, 44 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
>> index 28db7fb..fdf3032 100644
>> --- a/fs/9p/vfs_file.c
>> +++ b/fs/9p/vfs_file.c
>> @@ -290,6 +290,20 @@ static int v9fs_file_fsync(struct file *filp, int datasync)
>>         return retval;
>>   }
>>
>> +static int v9fs_file_fsync_dotl(struct file *filp, int datasync)
>> +{
>> +       struct p9_fid *fid;
>> +       int retval;
>> +
>> +       P9_DPRINTK(P9_DEBUG_VFS, "v9fs_file_fsync_dotl: filp %p datasync %x\n",
>> +                       filp, datasync);
>> +
>> +       fid = filp->private_data;
>> +
>> +       retval = p9_client_fsync(fid);
>> +       return retval;
>> +}
>> +
>>   static const struct file_operations v9fs_cached_file_operations = {
>>         .llseek = generic_file_llseek,
>>         .read = do_sync_read,
>> @@ -311,7 +325,7 @@ static const struct file_operations v9fs_cached_file_operations_dotl = {
>>         .release = v9fs_dir_release,
>>         .lock = v9fs_file_lock,
>>         .mmap = generic_file_readonly_mmap,
>> -       .fsync = v9fs_file_fsync,
>> +       .fsync = v9fs_file_fsync_dotl,
>>   };
>>
>>   const struct file_operations v9fs_file_operations = {
>> @@ -333,5 +347,5 @@ const struct file_operations v9fs_file_operations_dotl = {
>>         .release = v9fs_dir_release,
>>         .lock = v9fs_file_lock,
>>         .mmap = generic_file_readonly_mmap,
>> -       .fsync = v9fs_file_fsync,
>> +       .fsync = v9fs_file_fsync_dotl,
>>   };
>> diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
>> index a4a1b04..55e9605 100644
>> --- a/include/net/9p/9p.h
>> +++ b/include/net/9p/9p.h
>> @@ -163,6 +163,8 @@ enum p9_msg_t {
>>         P9_RXATTRCREATE,
>>         P9_TREADDIR = 40,
>>         P9_RREADDIR,
>> +       P9_TFSYNC = 50,
>> +       P9_RFSYNC,
>>         P9_TLINK = 70,
>>         P9_RLINK,
>>         P9_TMKDIR = 72,
>> diff --git a/include/net/9p/client.h b/include/net/9p/client.h
>> index d1aa2cf..fbb23b4 100644
>> --- a/include/net/9p/client.h
>> +++ b/include/net/9p/client.h
>> @@ -232,6 +232,7 @@ int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid,
>>   int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
>>                 gid_t gid, struct p9_qid *qid);
>>   int p9_client_clunk(struct p9_fid *fid);
>> +int p9_client_fsync(struct p9_fid *fid);
>>   int p9_client_remove(struct p9_fid *fid);
>>   int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
>>                                                         u64 offset, u32 count);
>> diff --git a/net/9p/client.c b/net/9p/client.c
>> index 208efce..124241b 100644
>> --- a/net/9p/client.c
>> +++ b/net/9p/client.c
>> @@ -1211,6 +1211,31 @@ int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
>>   }
>>   EXPORT_SYMBOL(p9_client_link);
>>
>> +int p9_client_fsync(struct p9_fid *fid)
>> +{
>> +       int err;
>> +       struct p9_client *clnt;
>> +       struct p9_req_t *req;
>> +
>> +       P9_DPRINTK(P9_DEBUG_9P, ">>>  TFSYNC fid %d\n", fid->fid);
>> +       err = 0;
>> +       clnt = fid->clnt;
>> +
>> +       req = p9_client_rpc(clnt, P9_TFSYNC, "d", fid->fid);
>> +       if (IS_ERR(req)) {
>> +               err = PTR_ERR(req);
>> +               goto error;
>> +       }
>> +
>> +       P9_DPRINTK(P9_DEBUG_9P, "<<<  RFSYNC fid %d\n", fid->fid);
>> +
>> +       p9_free_req(clnt, req);
>> +
>> +error:
>> +       return err;
>> +}
>> +EXPORT_SYMBOL(p9_client_fsync);
>> +
>>   int p9_client_clunk(struct p9_fid *fid)
>>   {
>>         int err;
>> --
>> 1.6.5.2
>>
>>
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