[PATCH][4/7] cifs: file.c cleanups in incremental bits - newcifs_open_inode_helper helper function

[Jesper Juhl]

This (attached) patch adds a new helper function to fs/cifs/file.c called 
cifs_open_inode_helper and convers cifs_open to use it.
The point of the patch is to a) reduce nesting, and b) shorten the very 
long cifs_open function.

Signed-off-by: Jesper Juhl <juhl-lkml@xxxxxx>


-- 
Jesper Juhl

diff -up linux-2.6.11-mm3/fs/cifs/file.c.with_patch_4 linux-2.6.11-mm3/fs/cifs/file.c
--- linux-2.6.11-mm3/fs/cifs/file.c.with_patch_4	2005-03-16 00:29:37.000000000 +0100
+++ linux-2.6.11-mm3/fs/cifs/file.c	2005-03-16 00:49:33.000000000 +0100
@@ -51,6 +51,72 @@ static inline struct cifsFileInfo *cifs_
 	return private_data;
 }
 
+/* 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,
+	struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
+	char *full_path, int xid)
+{
+	struct timespec temp;
+	int rc;
+
+	/* 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 prepare_write */
+	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
+		list_add_tail(&pCifsFile->flist, 
+			      &pCifsInode->openFileList);
+	} else {
+		list_add(&pCifsFile->flist,
+			 &pCifsInode->openFileList);
+	}
+	write_unlock(&GlobalSMBSeslock);
+	write_unlock(&file->f_owner.lock);
+	if (pCifsInode->clientCanCacheRead) {
+		/* we have the inode open somewhere else
+		   no need to discard cache data */
+		goto client_can_cache;
+	}
+
+	/* BB need same check in cifs_create too? */
+	/* 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_dentry->d_inode->i_mtime, &temp) && 
+			   (file->f_dentry->d_inode->i_size == 
+			    (loff_t)le64_to_cpu(buf->EndOfFile))) {
+		cFYI(1, ("inode unchanged on server"));
+	} else {
+		if (file->f_dentry->d_inode->i_mapping) {
+		/* BB no need to lock inode until after invalidate
+		   since namei code should already have it locked? */
+			filemap_fdatawrite(file->f_dentry->d_inode->i_mapping);
+			filemap_fdatawait(file->f_dentry->d_inode->i_mapping);
+		}
+		cFYI(1, ("invalidating remote inode since open detected it "
+			 "changed"));
+		invalidate_remote_inode(file->f_dentry->d_inode);
+	}
+
+client_can_cache:
+	if (pTcon->ses->capabilities & CAP_UNIX)
+		rc = cifs_get_inode_info_unix(&file->f_dentry->d_inode,
+			full_path, inode->i_sb, xid);
+	else
+		rc = cifs_get_inode_info(&file->f_dentry->d_inode,
+			full_path, buf, inode->i_sb, xid);
+
+	if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
+		pCifsInode->clientCanCacheAll = TRUE;
+		pCifsInode->clientCanCacheRead = TRUE;
+		cFYI(1, ("Exclusive Oplock granted on inode %p",
+			 file->f_dentry->d_inode));
+	} else if ((*oplock & 0xF) == OPLOCK_READ)
+		pCifsInode->clientCanCacheRead = TRUE;
+
+	return rc;
+}
+
 int cifs_open(struct inode *inode, struct file *file)
 {
 	int rc = -EACCES;
@@ -175,11 +241,13 @@ int cifs_open(struct inode *inode, struc
 		rc = -ENOMEM;
 		goto out;
 	}
+
 	tmppriv = kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 	if (!tmppriv) {
 		rc = -ENOMEM;
 		goto out;
 	}
+
 	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
 			 CREATE_NOT_DIR, &netfid, &oplock, buf,
 			 cifs_sb->local_nls);
@@ -195,61 +263,16 @@ int cifs_open(struct inode *inode, struc
 	write_lock(&GlobalSMBSeslock);
 	list_add(&pCifsFile->tlist, &pTcon->openFileList);
 
-			pCifsInode = CIFS_I(file->f_dentry->d_inode);
-			if (pCifsInode) {
-				/* 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 prepare_write */
-				if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
-					list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList);
-				} else {
-					list_add(&pCifsFile->flist, &pCifsInode->openFileList);
-				}
-				write_unlock(&GlobalSMBSeslock);
-				write_unlock(&file->f_owner.lock);
-				if (pCifsInode->clientCanCacheRead) {
-					/* we have the inode open somewhere else
-					   no need to discard cache data */
-				} else {
-					if (buf) {
-					/* BB need same check in cifs_create too? */
-
-					/* if not oplocked, invalidate inode pages if mtime 
-					   or file size changed */
-						struct timespec temp;
-						temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
-						if (timespec_equal(&file->f_dentry->d_inode->i_mtime, &temp) && 
-							(file->f_dentry->d_inode->i_size == (loff_t)le64_to_cpu(buf->EndOfFile))) {
-							cFYI(1, ("inode unchanged on server"));
-						} else {
-							if (file->f_dentry->d_inode->i_mapping) {
-							/* BB no need to lock inode until after invalidate*/
-							/* since namei code should already have it locked?*/
-								filemap_fdatawrite(file->f_dentry->d_inode->i_mapping);
-								filemap_fdatawait(file->f_dentry->d_inode->i_mapping);
-							}
-							cFYI(1, ("invalidating remote inode since open detected it changed"));
-							invalidate_remote_inode(file->f_dentry->d_inode);
-						}
-					}
-				}
-				if (pTcon->ses->capabilities & CAP_UNIX)
-					rc = cifs_get_inode_info_unix(&file->f_dentry->d_inode,
-						full_path, inode->i_sb, xid);
-				else
-					rc = cifs_get_inode_info(&file->f_dentry->d_inode,
-						full_path, buf, inode->i_sb, xid);
+	pCifsInode = CIFS_I(file->f_dentry->d_inode);
+	if (pCifsInode) {
+		rc = cifs_open_inode_helper(inode, file, pCifsInode,
+					    pCifsFile, pTcon,
+					    &oplock, buf, full_path, xid);
+	} else {
+		write_unlock(&GlobalSMBSeslock);
+		write_unlock(&file->f_owner.lock);
+	}
 
-				if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
-					pCifsInode->clientCanCacheAll = TRUE;
-					pCifsInode->clientCanCacheRead = TRUE;
-					cFYI(1, ("Exclusive Oplock granted on inode %p", file->f_dentry->d_inode));
-				} else if ((oplock & 0xF) == OPLOCK_READ)
-					pCifsInode->clientCanCacheRead = TRUE;
-			} else {
-				write_unlock(&GlobalSMBSeslock);
-				write_unlock(&file->f_owner.lock);
-			}
 	if (oplock & CIFS_CREATE_ACTION) {           
 		/* time to set mode which we can not set earlier due to
 		   problems creating new read-only files */