cifs: untangle server->maxBuf and CIFSMaxBufSize

server->maxBuf is the maximum SMB size (including header) that the
server can handle. CIFSMaxBufSize is the maximum amount of data (sans
header) that the client can handle. Currently maxBuf is being capped at
CIFSMaxBufSize + the max headers size, and the two values are used
somewhat interchangeably in the code.

This makes little sense as these two values are not related at all.
Separate them and make sure the code uses the right values in the right
places.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index b7df4bff3aaa473c4d34501591746d3ea344c88e..602326fa4a4f5b3e35d6225be0f10387277a1638 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -453,8 +453,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses)
                }
                server->sec_mode = (__u8)le16_to_cpu(rsp->SecurityMode);
                server->maxReq = le16_to_cpu(rsp->MaxMpxCount);
-               server->maxBuf = min((__u32)le16_to_cpu(rsp->MaxBufSize),
-                               (__u32)CIFSMaxBufSize + MAX_CIFS_HDR_SIZE);
+               server->maxBuf = le16_to_cpu(rsp->MaxBufSize);
                server->max_vcs = le16_to_cpu(rsp->MaxNumberVcs);
                /* even though we do not use raw we might as well set this
                accurately, in case we ever find a need for it */
@@ -561,8 +560,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses)
           little endian */
        server->maxReq = le16_to_cpu(pSMBr->MaxMpxCount);
        /* probably no need to store and check maxvcs */
-       server->maxBuf = min(le32_to_cpu(pSMBr->MaxBufferSize),
-                       (__u32) CIFSMaxBufSize + MAX_CIFS_HDR_SIZE);
+       server->maxBuf = le32_to_cpu(pSMBr->MaxBufferSize);
        server->max_rw = le32_to_cpu(pSMBr->MaxRawSize);
        cFYI(DBG2, "Max buf = %d", ses->server->maxBuf);
        server->capabilities = le32_to_cpu(pSMBr->Capabilities);
@@ -2812,8 +2810,7 @@ CIFSSMBQueryReparseLinkInfo(const int xid, struct cifs_tcon *tcon,
        pSMB->TotalDataCount = 0;
        pSMB->MaxParameterCount = cpu_to_le32(2);
        /* BB find exact data count max from sess structure BB */
-       pSMB->MaxDataCount = cpu_to_le32((tcon->ses->server->maxBuf -
-                                         MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
+       pSMB->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00);
        pSMB->MaxSetupCount = 4;
        pSMB->Reserved = 0;
        pSMB->ParameterOffset = 0;
@@ -3306,8 +3303,7 @@ smb_init_nttransact(const __u16 sub_command, const int setup_count,
        pSMB->Reserved = 0;
        pSMB->TotalParameterCount = cpu_to_le32(parm_len);
        pSMB->TotalDataCount  = 0;
-       pSMB->MaxDataCount = cpu_to_le32((tcon->ses->server->maxBuf -
-                                         MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
+       pSMB->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00);
        pSMB->ParameterCount = pSMB->TotalParameterCount;
        pSMB->DataCount  = pSMB->TotalDataCount;
        temp_offset = offsetof(struct smb_com_ntransact_req, Parms) +
@@ -3977,8 +3973,7 @@ findFirstRetry:
        params = 12 + name_len /* includes null */ ;
        pSMB->TotalDataCount = 0;       /* no EAs */
        pSMB->MaxParameterCount = cpu_to_le16(10);
-       pSMB->MaxDataCount = cpu_to_le16((tcon->ses->server->maxBuf -
-                                         MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
+       pSMB->MaxDataCount = cpu_to_le16(CIFSMaxBufSize & 0xFFFFFF00);
        pSMB->MaxSetupCount = 0;
        pSMB->Reserved = 0;
        pSMB->Flags = 0;
@@ -4052,8 +4047,7 @@ findFirstRetry:
                        psrch_inf->index_of_last_entry = 2 /* skip . and .. */ +
                                psrch_inf->entries_in_buffer;
                        lnoff = le16_to_cpu(parms->LastNameOffset);
-                       if (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE <
-                             lnoff) {
+                       if (CIFSMaxBufSize < lnoff) {
                                cERROR(1, "ignoring corrupt resume name");
                                psrch_inf->last_entry = NULL;
                                return rc;
@@ -4097,9 +4091,7 @@ int CIFSFindNext(const int xid, struct cifs_tcon *tcon,
        byte_count = 0;
        pSMB->TotalDataCount = 0;       /* no EAs */
        pSMB->MaxParameterCount = cpu_to_le16(8);
-       pSMB->MaxDataCount =
-               cpu_to_le16((tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE) &
-                               0xFFFFFF00);
+       pSMB->MaxDataCount = cpu_to_le16(CIFSMaxBufSize & 0xFFFFFF00);
        pSMB->MaxSetupCount = 0;
        pSMB->Reserved = 0;
        pSMB->Flags = 0;
@@ -4181,8 +4173,7 @@ int CIFSFindNext(const int xid, struct cifs_tcon *tcon,
                        psrch_inf->index_of_last_entry +=
                                psrch_inf->entries_in_buffer;
                        lnoff = le16_to_cpu(parms->LastNameOffset);
-                       if (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE <
-                             lnoff) {
+                       if (CIFSMaxBufSize < lnoff) {
                                cERROR(1, "ignoring corrupt resume name");
                                psrch_inf->last_entry = NULL;
                                return rc;
@@ -6035,12 +6026,7 @@ int CIFSSMBNotify(const int xid, struct cifs_tcon *tcon,
        pSMB->TotalParameterCount = 0 ;
        pSMB->TotalDataCount = 0;
        pSMB->MaxParameterCount = cpu_to_le32(2);
-       /* BB find exact data count max from sess structure BB */
-       pSMB->MaxDataCount = 0; /* same in little endian or be */
-/* BB VERIFY verify which is correct for above BB */
-       pSMB->MaxDataCount = cpu_to_le32((tcon->ses->server->maxBuf -
-                                            MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
-
+       pSMB->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00);
        pSMB->MaxSetupCount = 4;
        pSMB->Reserved = 0;
        pSMB->ParameterOffset = 0;

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 71beb02019709933015a14449a4dcb37e959e12d..a0077a5e06691944a28738972160a8442c509a9e 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -181,7 +181,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
                -EINVAL = invalid transact2
 
  */
-static int check2ndT2(struct smb_hdr *pSMB, unsigned int maxBufSize)
+static int check2ndT2(struct smb_hdr *pSMB)
 {
        struct smb_t2_rsp *pSMBt;
        int remaining;
@@ -214,9 +214,9 @@ static int check2ndT2(struct smb_hdr *pSMB, unsigned int maxBufSize)
 
        cFYI(1, "missing %d bytes from transact2, check next response",
                remaining);
-       if (total_data_size > maxBufSize) {
+       if (total_data_size > CIFSMaxBufSize) {
                cERROR(1, "TotalDataSize %d is over maximum buffer %d",
-                       total_data_size, maxBufSize);
+                       total_data_size, CIFSMaxBufSize);
                return -EINVAL;
        }
        return remaining;
@@ -486,7 +486,7 @@ find_cifs_mid(struct TCP_Server_Info *server, struct smb_hdr *buf,
                    mid->command != buf->Command)
                        continue;
 
-               if (*length == 0 && check2ndT2(buf, server->maxBuf) > 0) {
+               if (*length == 0 && check2ndT2(buf) > 0) {
                        /* We have a multipart transact2 resp */
                        *is_multi_rsp = true;
                        if (mid->resp_buf) {
@@ -3130,8 +3130,7 @@ try_mount_again:
                cFYI(DBG2, "no very large read support, rsize now 127K");
        }
        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->rsize = min(cifs_sb->rsize, CIFSMaxBufSize);
 
        cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info);
 

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 9f41a10523a1bad91ba0a9e8581ed89f552785e2..fd57165f55fa0bedaf9d5450b4680833d89272e7 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1868,7 +1868,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
                if ((pTcon->ses) &&
                        !(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
                        current_read_size = min_t(const int, current_read_size,
-                                       pTcon->ses->server->maxBuf - 128);
+                                       CIFSMaxBufSize);
                }
                rc = -EAGAIN;
                while (rc == -EAGAIN) {

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index d3e619692ee0f0437e26d9d91d61545859f248bc..c7d80e24f24ea43eaafa7246a2658e0bb794b705 100644 (file)
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -124,7 +124,9 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, SESSION_SETUP_ANDX *pSMB)
        /*      that we use in next few lines                               */
        /* Note that header is initialized to zero in header_assemble */
        pSMB->req.AndXCommand = 0xFF;
-       pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);
+       pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
+                                       CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
+                                       USHRT_MAX));
        pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
        pSMB->req.VcNumber = get_next_vcnum(ses);