On Wed, 13 Apr 2011 07:43:14 -0400 Jeff Layton <[email protected]> wrote:
> Now that we can handle larger wsizes in writepages, fix up the > negotiation of the wsize to allow for that. Make the code default to a > wsize of (128k - PAGE_CACHE_SIZE). That gives us a size that goes up to > the max frame size specified in RFC1001. > > If CAP_LARGE_WRITE_AND_X isn't set, then set that down to a the largest > size allowed by the protocol (2^16 - 1), or the specified wsize, > whichever is smaller. > > If a larger wsize is specified, then check to make sure the server > supports the POSIX extension that allows it to ignore the 128k limit. If > it doesn't then set it to the default value. > > Signed-off-by: Jeff Layton <[email protected]> > --- > fs/cifs/connect.c | 62 +++++++++++++++++++++++++++++++++++----------------- > 1 files changed, 42 insertions(+), 20 deletions(-) > > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 8f737d2..dc4de86 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -2600,23 +2600,6 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, > else /* default */ > cifs_sb->rsize = CIFSMaxBufSize; > > - if (pvolume_info->wsize > PAGEVEC_SIZE * PAGE_CACHE_SIZE) { > - cERROR(1, "wsize %d too large, using 4096 instead", > - pvolume_info->wsize); > - cifs_sb->wsize = 4096; > - } else if (pvolume_info->wsize) > - cifs_sb->wsize = pvolume_info->wsize; > - else > - cifs_sb->wsize = min_t(const int, > - PAGEVEC_SIZE * PAGE_CACHE_SIZE, > - 127*1024); > - /* old default of CIFSMaxBufSize was too small now > - that SMB Write2 can send multiple pages in kvec. > - RFC1001 does not describe what happens when frame > - bigger than 128K is sent so use that as max in > - conjunction with 52K kvec constraint on arch with 4K > - page size */ > - > if (cifs_sb->rsize < 2048) { > cifs_sb->rsize = 2048; > /* Windows ME may prefer this */ > @@ -2694,6 +2677,46 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, > "mount option supported"); > } > > +/* > + * default to a wsize of 128k - PAGE_CACHE_SIZE -- one page less than the > + * largest frame size described in RFC1001. This allows space for the header > + * without going over that by default. > + */ > +#define CIFS_MAX_RFC1001_WSIZE (128 * 1024 - PAGE_CACHE_SIZE) > + > +/* > + * It's possible to increase the wsize by setting the wsize parm directly > + * up to a hard limit of 2^24 - PAGE_CACHE_SIZE. That might make for > + * "interesting" allocation* problems during write however (as we have to > + * allocate an array of pointers for the pages). > + */ > +#define CIFS_MAX_WSIZE ((1<<24) - PAGE_CACHE_SIZE) > + > +/* If CAP_LARGE_WRITE_AND_X isn't set, then limit the wsize to 16 bits */ > +#define CIFS_MAX_SMALL_WRITEX_WSIZE (0xffff) > + > +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_MAX_RFC1001_WSIZE; > + > + /* no CAP_LARGE_WRITE_X? Limit it to 16 bits */ > + if (!(server->capabilities & CAP_LARGE_WRITE_X)) > + wsize = min_t(unsigned int, wsize, CIFS_MAX_SMALL_WRITEX_WSIZE); > + > + /* can server support 24-bit write sizes? (via UNIX extensions) */ > + if (tcon->unix_ext && !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP)) oops, logic bug here -- this should be: if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP)) ...I'll fix it in next version... > + wsize = min_t(unsigned int, wsize, CIFS_MAX_RFC1001_WSIZE); > + > + /* hard limit of CIFS_MAX_WSIZE */ > + wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE); > + > + return wsize; > +} > + > static int > is_path_accessible(int xid, struct cifs_tcon *tcon, > struct cifs_sb_info *cifs_sb, const char *full_path) > @@ -2884,13 +2907,12 @@ try_mount_again: > cifs_sb->rsize = 1024 * 127; > cFYI(DBG2, "no very large read support, rsize now 127K"); > } > - if (!(tcon->ses->capabilities & CAP_LARGE_WRITE_X)) > - cifs_sb->wsize = min(cifs_sb->wsize, > - (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)); > if (!(tcon->ses->capabilities & CAP_LARGE_READ_X)) > cifs_sb->rsize = min(cifs_sb->rsize, > (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)); > > + cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info); > + > remote_path_check: > /* check if a whole path (including prepath) is not remote */ > if (!rc && tcon) { -- Jeff Layton <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
