[PATCH][SMB3] fallocate worker function

[Steve French]

>From 08c80cdc50e0d327234288cb0f628fdf5e80bc8d Mon Sep 17 00:00:00 2001
From: Steve French <sfrench at localhost.localdomain>
Date: Sat, 19 Jul 2014 21:44:58 -0500
Subject: [PATCH] [CIFS] Add worker function to set allocation size

Adds setinfo worker function for SMB2/SMB3 support of SET_ALLOCATION_INFORMATION

Attached is one approach for adding the worker function to extend
a file's allocation size over SMB2/SMB3 mounts.   It is a very
small change to add a parm to SMB2_set_eof and seems the
easiest way.   I have experimented with two ways
of using this patch - via the fallocate VFS interface (in which
we have to be careful and check that we are not going
to shrink the file so that we follow the Linux semantics) and
an cifs/smb3 specific ioctl.  Before adding the second patch
though, I am waiting for more information.  I have asked
for clarification from Microsoft and also from JRA on
the behavior on the two server types (since I may have found
a Samba server bug) when testing this.

Signed-off-by: Steve French <smfrench at gmail.com>
---
 fs/cifs/smb2inode.c |  2 +-
 fs/cifs/smb2ops.c   |  3 ++-
 fs/cifs/smb2pdu.c   | 10 +++++++---
 fs/cifs/smb2proto.h |  2 +-
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 84c012a..0150182 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -91,7 +91,7 @@ smb2_open_op_close(const unsigned int xid, struct
cifs_tcon *tcon,
  case SMB2_OP_SET_EOF:
  tmprc = SMB2_set_eof(xid, tcon, fid.persistent_fid,
      fid.volatile_fid, current->tgid,
-     (__le64 *)data);
+     (__le64 *)data, false);
  break;
  case SMB2_OP_SET_INFO:
  tmprc = SMB2_set_info(xid, tcon, fid.persistent_fid,
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 787844b..ae1bff3 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -19,6 +19,7 @@

 #include <linux/pagemap.h>
 #include <linux/vfs.h>
+#include <linux/falloc.h>
 #include "cifsglob.h"
 #include "smb2pdu.h"
 #include "smb2proto.h"
@@ -687,7 +688,7 @@ smb2_set_file_size(const unsigned int xid, struct
cifs_tcon *tcon,
 {
  __le64 eof = cpu_to_le64(size);
  return SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
-    cfile->fid.volatile_fid, cfile->pid, &eof);
+    cfile->fid.volatile_fid, cfile->pid, &eof, false);
 }

 static int
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b0b260d..49d14b6 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2325,7 +2325,7 @@ SMB2_set_hardlink(const unsigned int xid, struct
cifs_tcon *tcon,

 int
 SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon, u64
persistent_fid,
-     u64 volatile_fid, u32 pid, __le64 *eof)
+     u64 volatile_fid, u32 pid, __le64 *eof, bool is_falloc)
 {
  struct smb2_file_eof_info info;
  void *data;
@@ -2336,8 +2336,12 @@ SMB2_set_eof(const unsigned int xid, struct
cifs_tcon *tcon, u64 persistent_fid,
  data = &info;
  size = sizeof(struct smb2_file_eof_info);

- return send_set_info(xid, tcon, persistent_fid, volatile_fid, pid,
-     FILE_END_OF_FILE_INFORMATION, 1, &data, &size);
+ if (is_falloc)
+ return send_set_info(xid, tcon, persistent_fid, volatile_fid,
+ pid, FILE_ALLOCATION_INFORMATION, 1, &data, &size);
+ else
+ return send_set_info(xid, tcon, persistent_fid, volatile_fid,
+ pid, FILE_END_OF_FILE_INFORMATION, 1, &data, &size);
 }

 int
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 0ce48db..67e8ce8 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -139,7 +139,7 @@ extern int SMB2_set_hardlink(const unsigned int
xid, struct cifs_tcon *tcon,
      __le16 *target_file);
 extern int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon,
  u64 persistent_fid, u64 volatile_fid, u32 pid,
- __le64 *eof);
+ __le64 *eof, bool is_fallocate);
 extern int SMB2_set_info(const unsigned int xid, struct cifs_tcon *tcon,
  u64 persistent_fid, u64 volatile_fid,
  FILE_BASIC_INFO *buf);
-- 
1.9.3


-- 
Thanks,

Steve
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