[CIFS] Allow for 15 minute TZs (e.g. Nepal) and be more explicit about

not setting time on close

Signed-off-by: Guenter Kukkukk <linux@kukkukk.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

2 files changed, 25 insertions, 14 deletions

diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 50505422dbb4..6df9dadba647 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -409,6 +409,8 @@ typedef struct negotiate_req {
 
 /* Dialect index is 13 for LANMAN */
 
+#define MIN_TZ_ADJ (15 * 60) /* minimum grid for timezones in seconds */
+
 typedef struct lanman_neg_rsp {
         struct smb_hdr hdr;     /* wct = 13 */
         __le16 DialectIndex;
@@ -678,7 +680,7 @@ typedef union smb_com_tree_disconnect {	/* as an altetnative can use flag on
 typedef struct smb_com_close_req {
         struct smb_hdr hdr;     /* wct = 3 */
         __u16 FileID;
-        __u32 LastWriteTime;    /* should be zero */
+        __u32 LastWriteTime;    /* should be zero or -1 */
         __u16 ByteCount;        /* 0 */
 } __attribute__((packed)) CLOSE_REQ;
 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 75f060328e29..8d30a5c4f244 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -450,7 +450,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
         } else if((pSMBr->hdr.WordCount == 13)
                         && ((pSMBr->DialectIndex == LANMAN_PROT)
                                 || (pSMBr->DialectIndex == LANMAN2_PROT))) {
-                int tmp, adjust;
+                __s16 tmp;
                 struct lanman_neg_rsp * rsp = (struct lanman_neg_rsp *)pSMBr;
 
                 if((secFlags & CIFSSEC_MAY_LANMAN) || 
@@ -476,14 +476,16 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
                         server->maxRw = 0;/* we do not need to use raw anyway */
                         server->capabilities = CAP_MPX_MODE;
                 }
-                tmp = le16_to_cpu(rsp->ServerTimeZone);
-                if (tmp == (int)0xffff) {
+                tmp = (__s16)le16_to_cpu(rsp->ServerTimeZone);
+                if (tmp == 0xffff) {
                         /* OS/2 often does not set timezone therefore
                          * we must use server time to calc time zone.
-                         * Could deviate slightly from the right zone. Not easy
-                         * to adjust, since timezones are not always a multiple
-                         * of 60 (sometimes 30 minutes - are there smaller?)
+                         * Could deviate slightly from the right zone.
+                         * Smallest defined timezone difference is 15 minutes
+                         * (i.e. Nepal).  Rounding up/down is done to match
+                         * this requirement.
                          */
+                        int val, seconds, remain, result;
                         struct timespec ts, utc;
                         utc = CURRENT_TIME;
                         ts = cnvrtDosUnixTm(le16_to_cpu(rsp->SrvTime.Date),
@@ -491,12 +493,18 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
                         cFYI(1,("SrvTime: %d sec since 1970 (utc: %d) diff: %d",
                                 (int)ts.tv_sec, (int)utc.tv_sec, 
                                 (int)(utc.tv_sec - ts.tv_sec)));
-                        tmp = (int)(utc.tv_sec - ts.tv_sec);
-                        adjust = tmp < 0 ? -29 : 29;
-                        tmp = ((tmp + adjust) / 60) * 60;
-                        server->timeAdj = tmp;
+                        val = (int)(utc.tv_sec - ts.tv_sec);
+                        seconds = val < 0 ? -val : val;
+                        result = (seconds / IN_TZ_ADJ) * MIN_TZ_ADJ;
+                        remain = seconds % MIN_TZ_ADJ;
+                        if(remain >= (MIN_TZ_ADJ / 2))
+                                result += MIN_TZ_ADJ;
+                        if(val < 0)
+                                result = - result;
+                        server->timeAdj = result;
                 } else {
-                        server->timeAdj = tmp * 60; /* also in seconds */
+                        server->timeAdj = (int)tmp;
+                        server->timeAdj *= 60; /* also in seconds */
                 }
                 cFYI(1,("server->timeAdj: %d seconds", server->timeAdj));
 
@@ -559,7 +567,8 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
         cFYI(0, ("Max buf = %d", ses->server->maxBuf));
         GETU32(ses->server->sessid) = le32_to_cpu(pSMBr->SessionKey);
         server->capabilities = le32_to_cpu(pSMBr->Capabilities);
-        server->timeAdj = le16_to_cpu(pSMBr->ServerTimeZone) * 60;      
+        server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone);
+        server->timeAdj *= 60;
         if (pSMBr->EncryptionKeyLength == CIFS_CRYPTO_KEY_SIZE) {
                 memcpy(server->cryptKey, pSMBr->u.EncryptionKey,
                        CIFS_CRYPTO_KEY_SIZE);
@@ -1645,7 +1654,7 @@ CIFSSMBClose(const int xid, struct cifsTconInfo *tcon, int smb_file_id)
         pSMBr = (CLOSE_RSP *)pSMB; /* BB removeme BB */
 
         pSMB->FileID = (__u16) smb_file_id;
-        pSMB->LastWriteTime = 0;
+        pSMB->LastWriteTime = 0xFFFFFFFF;
         pSMB->ByteCount = 0;
         rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
                          (struct smb_hdr *) pSMBr, &bytes_returned, 0);