[CIFS] Avoid extra large buffer allocation (and memcpy) in cifs_readpages

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 32 insertions, 20 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index b67be3d8c019..c249b628fd1c 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -555,13 +555,13 @@ int cifs_closedir(struct inode *inode, struct file *file)
                 }
                 ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
                 if (ptmp) {
-   /* BB removeme BB */ cFYI(1, ("freeing smb buf in srch struct in closedir"));
+                        cFYI(1, ("closedir free smb buf in srch struct"));
                         pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
                         cifs_buf_release(ptmp);
                 }
                 ptmp = pCFileStruct->search_resume_name;
                 if (ptmp) {
-   /* BB removeme BB */ cFYI(1, ("freeing resume name in closedir"));
+                        cFYI(1, ("closedir free resume name"));
                         pCFileStruct->search_resume_name = NULL;
                         kfree(ptmp);
                 }
@@ -871,8 +871,8 @@ static ssize_t cifs_write(struct file *file, const char *write_data,
                                         break;
                         }
                         /* BB FIXME We can not sign across two buffers yet */
-                        if((experimEnabled) && ((pTcon->ses->server->secMode & 
-                         (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) == 0)) {
+                        if((pTcon->ses->server->secMode & 
+                         (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) == 0) {
                                 struct kvec iov[2];
                                 unsigned int len;
 
@@ -1424,6 +1424,7 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
                 rc = -EAGAIN;
                 smb_read_data = NULL;
                 while (rc == -EAGAIN) {
+                        int buf_type = CIFS_NO_BUFFER;
                         if ((open_file->invalidHandle) && 
                             (!open_file->closePend)) {
                                 rc = cifs_reopen_file(file->f_dentry->d_inode,
@@ -1432,20 +1433,22 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
                                         break;
                         }
                         rc = CIFSSMBRead(xid, pTcon,
-                                        open_file->netfid,
-                                        current_read_size, *poffset,
-                                        &bytes_read, &smb_read_data);
+                                         open_file->netfid,
+                                         current_read_size, *poffset,
+                                         &bytes_read, &smb_read_data,
+                                         &buf_type);
                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
                         if (copy_to_user(current_offset, 
                                          smb_read_data + 4 /* RFC1001 hdr */
                                          + le16_to_cpu(pSMBr->DataOffset), 
                                          bytes_read)) {
                                 rc = -EFAULT;
-                                FreeXid(xid);
-                                return rc;
-            }
+                        }
                         if (smb_read_data) {
-                                cifs_buf_release(smb_read_data);
+                                if(buf_type == CIFS_SMALL_BUFFER)
+                                        cifs_small_buf_release(smb_read_data);
+                                else if(buf_type == CIFS_LARGE_BUFFER)
+                                        cifs_buf_release(smb_read_data);
                                 smb_read_data = NULL;
                         }
                 }
@@ -1478,6 +1481,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
         int xid;
         char *current_offset;
         struct cifsFileInfo *open_file;
+        int buf_type = CIFS_NO_BUFFER;
 
         xid = GetXid();
         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
@@ -1514,9 +1518,10 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
                                         break;
                         }
                         rc = CIFSSMBRead(xid, pTcon,
-                                        open_file->netfid,
-                                        current_read_size, *poffset,
-                                        &bytes_read, &current_offset);
+                                         open_file->netfid,
+                                         current_read_size, *poffset,
+                                         &bytes_read, &current_offset,
+                                         &buf_type);
                 }
                 if (rc || (bytes_read == 0)) {
                         if (total_read) {
@@ -1614,6 +1619,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
         struct smb_com_read_rsp *pSMBr;
         struct pagevec lru_pvec;
         struct cifsFileInfo *open_file;
+        int buf_type = CIFS_NO_BUFFER;
 
         xid = GetXid();
         if (file->private_data == NULL) {
@@ -1670,14 +1676,17 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
                         }
 
                         rc = CIFSSMBRead(xid, pTcon,
-                                        open_file->netfid,
-                                        read_size, offset,
-                                        &bytes_read, &smb_read_data);
-
+                                         open_file->netfid,
+                                         read_size, offset,
+                                         &bytes_read, &smb_read_data,
+                                         &buf_type);
                         /* BB more RC checks ? */
                         if (rc== -EAGAIN) {
                                 if (smb_read_data) {
-                                        cifs_buf_release(smb_read_data);
+                                        if(buf_type == CIFS_SMALL_BUFFER)
+                                                cifs_small_buf_release(smb_read_data);
+                                        else if(buf_type == CIFS_LARGE_BUFFER)
+                                                cifs_buf_release(smb_read_data);
                                         smb_read_data = NULL;
                                 }
                         }
@@ -1734,7 +1743,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
                         break;
                 }
                 if (smb_read_data) {
-                        cifs_buf_release(smb_read_data);
+                        if(buf_type == CIFS_SMALL_BUFFER)
+                                cifs_small_buf_release(smb_read_data);
+                        else if(buf_type == CIFS_LARGE_BUFFER)
+                                cifs_buf_release(smb_read_data);
                         smb_read_data = NULL;
                 }
                 bytes_read = 0;