This patch is intended for 2.6.39-stable kernels only and is needed to fix a regression introduced in 2.6.39. Prior to 2.6.39, when signing was enabled on a socket the client only sent single-page writes. This changed with commit ca83ce3, which made signed and unsigned connections use the same codepaths for write calls. This caused a regression when working with windows servers. Windows machines will reject writes larger than the MaxBufferSize when signing is active, but do not clear the CAP_LARGE_WRITE_X flag in the protocol negotiation. The upshot is that when signing is active, windows servers often reject large writes from the client in 2.6.39. Because 3.0 adds support for larger wsize values, simply cherry picking the upstream patches that fix the wsize negotiation isn't sufficient to fix this issue. We also need to alter the maximum and default values to something suitable for 2.6.39. Cc: <stable@xxxxxxxxxx> # .39.x: f7910cb: cifs: clean up wsize negotiation and allow for larger wsize Cc: <stable@xxxxxxxxxx> # .39.x: 1190f6a: cifs: fix wsize negotiation to respect max buffer size and active signing (try #4) Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- fs/cifs/connect.c | 20 ++++---------------- 1 files changed, 4 insertions(+), 16 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 599f485..8e78710 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2648,16 +2648,8 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, "mount option supported"); } -/* - * When the server supports very large writes via POSIX extensions, we can - * allow up to 2^24-1, minus the size of a 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. - */ -#define CIFS_MAX_WSIZE ((1<<24) - 1 - sizeof(WRITE_REQ) + 4) +/* Prior to 3.0, cifs couldn't handle writes larger than this */ +#define CIFS_MAX_WSIZE (PAGEVEC_SIZE * PAGE_CACHE_SIZE) /* * When the server doesn't allow large posix writes, only allow a wsize of @@ -2666,12 +2658,8 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, */ #define CIFS_MAX_RFC1002_WSIZE (128 * 1024 - sizeof(WRITE_REQ) + 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_WSIZE (1024 * 1024) +/* Make the default the same as the max */ +#define CIFS_DEFAULT_WSIZE CIFS_MAX_WSIZE static unsigned int cifs_negotiate_wsize(struct cifsTconInfo *tcon, struct smb_vol *pvolume_info) -- 1.7.6 -- 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
