diff options
| -rw-r--r-- | fs/cifs/connect.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index f3670cf72587..63e4be46eec4 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2914,18 +2914,33 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, #define CIFS_DEFAULT_IOSIZE (1024 * 1024) /* - * Windows only supports a max of 60k reads. Default to that when posix - * extensions aren't in force. + * 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) 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 = pvolume_info->wsize ? pvolume_info->wsize : - CIFS_DEFAULT_IOSIZE; + 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)) |