diff options
| author | Jeff Layton <jlayton@redhat.com> | 2012-01-17 16:08:51 -0500 |
|---|---|---|
| committer | Steve French <smfrench@gmail.com> | 2012-01-17 22:39:37 -0600 |
| commit | ce91acb3acae26f4163c5a6f1f695d1a1e8d9009 (patch) | |
| tree | 99fb4bf5e536de370b6d3378199982ff4c829b69 /fs/cifs | |
| parent | f5fffcee27c09143ba80e5257dbd1f381d86342f (diff) | |
| download | lwn-ce91acb3acae26f4163c5a6f1f695d1a1e8d9009.tar.gz lwn-ce91acb3acae26f4163c5a6f1f695d1a1e8d9009.zip | |
cifs: lower default wsize when unix extensions are not used
We've had some reports of servers (namely, the Solaris in-kernel CIFS
server) that don't deal properly with writes that are "too large" even
though they set CAP_LARGE_WRITE_ANDX. Change the default to better
mirror what windows clients do.
Cc: stable@vger.kernel.org
Cc: Pavel Shilovsky <piastry@etersoft.ru>
Reported-by: Nick Davis <phireph0x@yahoo.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs')
| -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 5cc15856e4ad..a66dcb52988c 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2930,18 +2930,33 @@ 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)) |