CIFS: Move r/wsize negotiating to ops struct

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 6df6fa1..c31b30b 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3261,146 +3261,6 @@
 			   "mount option supported");
 }
 
-/*
- * When the server supports very large reads and writes via POSIX extensions,
- * we can allow up to 2^24-1, minus the size of a READ/WRITE_AND_X header, not
- * including the RFC1001 length.
- *
- * Note that this might make for "interesting" allocation problems during
- * writeback however as we have to allocate an array of pointers for the
- * pages. A 16M write means ~32kb page array with PAGE_CACHE_SIZE == 4096.
- *
- * For reads, there is a similar problem as we need to allocate an array
- * of kvecs to handle the receive, though that should only need to be done
- * once.
- */
-#define CIFS_MAX_WSIZE ((1<<24) - 1 - sizeof(WRITE_REQ) + 4)
-#define CIFS_MAX_RSIZE ((1<<24) - sizeof(READ_RSP) + 4)
-
-/*
- * When the server doesn't allow large posix writes, only allow a rsize/wsize
- * of 2^17-1 minus the size of the call header. That allows for a read or
- * write up to the maximum size described by RFC1002.
- */
-#define CIFS_MAX_RFC1002_WSIZE ((1<<17) - 1 - sizeof(WRITE_REQ) + 4)
-#define CIFS_MAX_RFC1002_RSIZE ((1<<17) - 1 - sizeof(READ_RSP) + 4)
-
-/*
- * The default wsize is 1M. find_get_pages seems to return a maximum of 256
- * pages in a single call. With PAGE_CACHE_SIZE == 4k, this means we can fill
- * a single wsize request with a single call.
- */
-#define CIFS_DEFAULT_IOSIZE (1024 * 1024)
-
-/*
- * Windows only supports a max of 60kb reads and 65535 byte writes. Default to
- * those values when posix extensions aren't in force. In actuality here, we
- * use 65536 to allow for a write that is a multiple of 4k. Most servers seem
- * to be ok with the extra byte even though Windows doesn't send writes that
- * are that large.
- *
- * Citation:
- *
- * http://blogs.msdn.com/b/openspecification/archive/2009/04/10/smb-maximum-transmit-buffer-size-and-performance-tuning.aspx
- */
-#define CIFS_DEFAULT_NON_POSIX_RSIZE (60 * 1024)
-#define CIFS_DEFAULT_NON_POSIX_WSIZE (65536)
-
-/*
- * On hosts with high memory, we can't currently support wsize/rsize that are
- * larger than we can kmap at once. Cap the rsize/wsize at
- * LAST_PKMAP * PAGE_SIZE. We'll never be able to fill a read or write request
- * larger than that anyway.
- */
-#ifdef CONFIG_HIGHMEM
-#define CIFS_KMAP_SIZE_LIMIT	(LAST_PKMAP * PAGE_CACHE_SIZE)
-#else /* CONFIG_HIGHMEM */
-#define CIFS_KMAP_SIZE_LIMIT	(1<<24)
-#endif /* CONFIG_HIGHMEM */
-
-static unsigned int
-cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
-{
-	__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
-	struct TCP_Server_Info *server = tcon->ses->server;
-	unsigned int wsize;
-
-	/* start with specified wsize, or default */
-	if (pvolume_info->wsize)
-		wsize = pvolume_info->wsize;
-	else if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
-		wsize = CIFS_DEFAULT_IOSIZE;
-	else
-		wsize = CIFS_DEFAULT_NON_POSIX_WSIZE;
-
-	/* can server support 24-bit write sizes? (via UNIX extensions) */
-	if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
-		wsize = min_t(unsigned int, wsize, CIFS_MAX_RFC1002_WSIZE);
-
-	/*
-	 * no CAP_LARGE_WRITE_X or is signing enabled without CAP_UNIX set?
-	 * Limit it to max buffer offered by the server, minus the size of the
-	 * WRITEX header, not including the 4 byte RFC1001 length.
-	 */
-	if (!(server->capabilities & CAP_LARGE_WRITE_X) ||
-	    (!(server->capabilities & CAP_UNIX) &&
-	     (server->sec_mode & (SECMODE_SIGN_ENABLED|SECMODE_SIGN_REQUIRED))))
-		wsize = min_t(unsigned int, wsize,
-				server->maxBuf - sizeof(WRITE_REQ) + 4);
-
-	/* limit to the amount that we can kmap at once */
-	wsize = min_t(unsigned int, wsize, CIFS_KMAP_SIZE_LIMIT);
-
-	/* hard limit of CIFS_MAX_WSIZE */
-	wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE);
-
-	return wsize;
-}
-
-static unsigned int
-cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
-{
-	__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
-	struct TCP_Server_Info *server = tcon->ses->server;
-	unsigned int rsize, defsize;
-
-	/*
-	 * Set default value...
-	 *
-	 * HACK alert! Ancient servers have very small buffers. Even though
-	 * MS-CIFS indicates that servers are only limited by the client's
-	 * bufsize for reads, testing against win98se shows that it throws
-	 * INVALID_PARAMETER errors if you try to request too large a read.
-	 * OS/2 just sends back short reads.
-	 *
-	 * If the server doesn't advertise CAP_LARGE_READ_X, then assume that
-	 * it can't handle a read request larger than its MaxBufferSize either.
-	 */
-	if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_READ_CAP))
-		defsize = CIFS_DEFAULT_IOSIZE;
-	else if (server->capabilities & CAP_LARGE_READ_X)
-		defsize = CIFS_DEFAULT_NON_POSIX_RSIZE;
-	else
-		defsize = server->maxBuf - sizeof(READ_RSP);
-
-	rsize = pvolume_info->rsize ? pvolume_info->rsize : defsize;
-
-	/*
-	 * no CAP_LARGE_READ_X? Then MS-CIFS states that we must limit this to
-	 * the client's MaxBufferSize.
-	 */
-	if (!(server->capabilities & CAP_LARGE_READ_X))
-		rsize = min_t(unsigned int, CIFSMaxBufSize, rsize);
-
-	/* limit to the amount that we can kmap at once */
-	rsize = min_t(unsigned int, rsize, CIFS_KMAP_SIZE_LIMIT);
-
-	/* hard limit of CIFS_MAX_RSIZE */
-	rsize = min_t(unsigned int, rsize, CIFS_MAX_RSIZE);
-
-	return rsize;
-}
-
 static void
 cleanup_volume_info_contents(struct smb_vol *volume_info)
 {
@@ -3651,8 +3511,8 @@
 	if (!tcon->ipc && server->ops->qfs_tcon)
 		server->ops->qfs_tcon(xid, tcon);
 
-	cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info);
-	cifs_sb->rsize = cifs_negotiate_rsize(tcon, volume_info);
+	cifs_sb->wsize = server->ops->negotiate_wsize(tcon, volume_info);
+	cifs_sb->rsize = server->ops->negotiate_rsize(tcon, volume_info);
 
 	/* tune readahead according to rsize */
 	cifs_sb->bdi.ra_pages = cifs_sb->rsize / PAGE_CACHE_SIZE;