fs/9p: add 9P2000.L unlinkat operation

unlinkat - Remove a directory entry

size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4]
size[4] Runlinkat tag[2]

older Tremove have the below request format

size[4] Tremove tag[2] fid[4]

The remove message is used to remove a directory entry either file or directory
The remove opreation is actually a directory opertation and should ideally have
dirfid, if not we cannot represent the fid on server with anything other than
name. We will have to derive the directory name from fid in the Tremove request.

NOTE: The operation doesn't clunk the unlink fid.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 3 insertions, 0 deletions

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 61156207c98c..342dcf13d039 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -183,6 +183,8 @@ enum p9_msg_t {
         P9_RMKDIR,
         P9_TRENAMEAT = 74,
         P9_RRENAMEAT,
+        P9_TUNLINKAT = 76,
+        P9_RUNLINKAT,
         P9_TVERSION = 100,
         P9_RVERSION,
         P9_TAUTH = 102,
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 62ceddf9994a..55ce72ce9861 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -234,6 +234,7 @@ int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_fsync(struct p9_fid *fid, int datasync);
 int p9_client_remove(struct p9_fid *fid);
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
 int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
                                                         u64 offset, u32 count);
 int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,