[CIFS] Use posix open on file open when server supports it

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

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e4ecb1c..7bef4cc 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -124,6 +124,80 @@ static inline int cifs_get_disposition(unsigned int flags)
                return FILE_OPEN;
 }
 
+/* all arguments to this function must be checked for validity in caller */
+static inline int cifs_posix_open_inode_helper(struct inode *inode,
+                       struct file *file, struct cifsInodeInfo *pCifsInode,
+                       struct cifsFileInfo *pCifsFile, int oplock, u16 netfid)
+{
+       struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+/*     struct timespec temp; */   /* BB REMOVEME BB */
+
+       file->private_data = kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
+       if (file->private_data == NULL)
+               return -ENOMEM;
+       pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
+       write_lock(&GlobalSMBSeslock);
+       list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
+
+       pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
+       if (pCifsInode == NULL) {
+               write_unlock(&GlobalSMBSeslock);
+               return -EINVAL;
+       }
+
+       /* want handles we can use to read with first
+          in the list so we do not have to walk the
+          list to search for one in write_begin */
+       if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
+               list_add_tail(&pCifsFile->flist,
+                             &pCifsInode->openFileList);
+       } else {
+               list_add(&pCifsFile->flist,
+                        &pCifsInode->openFileList);
+       }
+
+       if (pCifsInode->clientCanCacheRead) {
+               /* we have the inode open somewhere else
+                  no need to discard cache data */
+               goto psx_client_can_cache;
+       }
+
+       /* BB FIXME need to fix this check to move it earlier into posix_open
+          BB  fIX following section BB FIXME */
+
+       /* if not oplocked, invalidate inode pages if mtime or file
+          size changed */
+/*     temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
+       if (timespec_equal(&file->f_path.dentry->d_inode->i_mtime, &temp) &&
+                          (file->f_path.dentry->d_inode->i_size ==
+                           (loff_t)le64_to_cpu(buf->EndOfFile))) {
+               cFYI(1, ("inode unchanged on server"));
+       } else {
+               if (file->f_path.dentry->d_inode->i_mapping) {
+                       rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping);
+                       if (rc != 0)
+                               CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc;
+               }
+               cFYI(1, ("invalidating remote inode since open detected it "
+                        "changed"));
+               invalidate_remote_inode(file->f_path.dentry->d_inode);
+       } */
+
+psx_client_can_cache:
+       if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
+               pCifsInode->clientCanCacheAll = true;
+               pCifsInode->clientCanCacheRead = true;
+               cFYI(1, ("Exclusive Oplock granted on inode %p",
+                        file->f_path.dentry->d_inode));
+       } else if ((oplock & 0xF) == OPLOCK_READ)
+               pCifsInode->clientCanCacheRead = true;
+
+       /* will have to change the unlock if we reenable the
+          filemap_fdatawrite (which does not seem necessary */
+       write_unlock(&GlobalSMBSeslock);
+       return 0;
+}
+
 /* all arguments to this function must be checked for validity in caller */
 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
        struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
@@ -195,7 +269,7 @@ int cifs_open(struct inode *inode, struct file *file)
        int rc = -EACCES;
        int xid, oplock;
        struct cifs_sb_info *cifs_sb;
-       struct cifsTconInfo *pTcon;
+       struct cifsTconInfo *tcon;
        struct cifsFileInfo *pCifsFile;
        struct cifsInodeInfo *pCifsInode;
        struct list_head *tmp;
@@ -208,7 +282,7 @@ int cifs_open(struct inode *inode, struct file *file)
        xid = GetXid();
 
        cifs_sb = CIFS_SB(inode->i_sb);
-       pTcon = cifs_sb->tcon;
+       tcon = cifs_sb->tcon;
 
        if (file->f_flags & O_CREAT) {
                /* search inode for this file and fill in file->private_data */
@@ -248,6 +322,35 @@ int cifs_open(struct inode *inode, struct file *file)
 
        cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
                 inode, file->f_flags, full_path));
+
+       if (oplockEnabled)
+               oplock = REQ_OPLOCK;
+       else
+               oplock = 0;
+
+       if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
+           (CIFS_UNIX_POSIX_PATH_OPS_CAP &
+                       le64_to_cpu(tcon->fsUnixInfo.Capability))) {
+               int oflags = (int) cifs_posix_convert_flags(file->f_flags);
+               /* can not refresh inode info since size could be stale */
+               rc = cifs_posix_open(full_path, &inode, inode->i_sb,
+                                    cifs_sb->mnt_file_mode /* ignored */,
+                                    oflags, &oplock, &netfid, xid);
+               if (rc == 0) {
+                       cFYI(1, ("posix open succeeded"));
+                       /* no need for special case handling of setting mode
+                          on read only files needed here */
+
+                       cifs_posix_open_inode_helper(inode, file, pCifsInode,
+                                                    pCifsFile, oplock, netfid);
+                       goto out;
+               } else if ((rc != -EIO) && (rc != -EREMOTE) &&
+                        (rc != -EOPNOTSUPP)) /* path not found or net err */
+                       goto out;
+               /* fallthrough to retry open the old way on operation
+                  not supported or DFS errors */
+       }
+
        desiredAccess = cifs_convert_flags(file->f_flags);
 
 /*********************************************************************
@@ -276,11 +379,6 @@ int cifs_open(struct inode *inode, struct file *file)
 
        disposition = cifs_get_disposition(file->f_flags);
 
-       if (oplockEnabled)
-               oplock = REQ_OPLOCK;
-       else
-               oplock = 0;
-
        /* BB pass O_SYNC flag through on file attributes .. BB */
 
        /* Also refresh inode by passing in file_info buf returned by SMBOpen
@@ -297,7 +395,7 @@ int cifs_open(struct inode *inode, struct file *file)
        }
 
        if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
-               rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
+               rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
                         desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
                         cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
                                 & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -306,7 +404,7 @@ int cifs_open(struct inode *inode, struct file *file)
 
        if (rc == -EIO) {
                /* Old server, try legacy style OpenX */
-               rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
+               rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
                        desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
                        cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
                                & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -323,12 +421,12 @@ int cifs_open(struct inode *inode, struct file *file)
        }
        pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
        write_lock(&GlobalSMBSeslock);
-       list_add(&pCifsFile->tlist, &pTcon->openFileList);
+       list_add(&pCifsFile->tlist, &tcon->openFileList);
 
        pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
        if (pCifsInode) {
                rc = cifs_open_inode_helper(inode, file, pCifsInode,
-                                           pCifsFile, pTcon,
+                                           pCifsFile, tcon,
                                            &oplock, buf, full_path, xid);
        } else {
                write_unlock(&GlobalSMBSeslock);
@@ -337,7 +435,7 @@ int cifs_open(struct inode *inode, struct file *file)
        if (oplock & CIFS_CREATE_ACTION) {
                /* time to set mode which we can not set earlier due to
                   problems creating new read-only files */
-               if (pTcon->unix_ext) {
+               if (tcon->unix_ext) {
                        struct cifs_unix_set_info_args args = {
                                .mode   = inode->i_mode,
                                .uid    = NO_CHANGE_64,
@@ -347,7 +445,7 @@ int cifs_open(struct inode *inode, struct file *file)
                                .mtime  = NO_CHANGE_64,
                                .device = 0,
                        };
-                       CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
+                       CIFSSMBUnixSetInfo(xid, tcon, full_path, &args,
                                            cifs_sb->local_nls,
                                            cifs_sb->mnt_cifs_flags &
                                                CIFS_MOUNT_MAP_SPECIAL_CHR);