On Wed, 9 Nov 2011 13:37:23 -0500 Jeff Layton <jlayton@xxxxxxxxxx> wrote: > 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: Pavel Shilovsky <piastry@xxxxxxxxxxx> > Reported-by: Nick Davis <phireph0x@xxxxxxxxx> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > --- > 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 d6a972d..bf82f88 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -2912,18 +2912,33 @@ 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)) I should also mention that I suspect that this will fix this bug without needing extra options: https://bugzilla.samba.org/show_bug.cgi?id=8559 If it looks acceptable, this might be suitable for stable too. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
