cifs: pass instantiated filp back after open call
Jeff Layton [Wed, 16 Jun 2010 17:40:16 +0000 (13:40 -0400)]
The current scheme of sticking open files on a list and assuming that
cifs_open will scoop them off of it is broken and leads to "Busy
inodes after umount..." errors at unmount time.

The problem is that there is no guarantee that cifs_open will always
be called after a ->lookup or ->create operation. If there are
permissions or other problems, then it's quite likely that it *won't*
be called.

Fix this by fully instantiating the filp whenever the file is created
and pass that filp back to the VFS. If there is a problem, the VFS
can clean up the references.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>

fs/cifs/dir.c
fs/cifs/file.c

index f49afb9..e7ae78b 100644 (file)
@@ -25,6 +25,7 @@
 #include <linux/slab.h>
 #include <linux/namei.h>
 #include <linux/mount.h>
+#include <linux/file.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
@@ -184,6 +185,8 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
        }
        write_unlock(&GlobalSMBSeslock);
 
+       file->private_data = pCifsFile;
+
        return pCifsFile;
 }
 
@@ -463,14 +466,22 @@ cifs_create_set_dentry:
 
        if (newinode && nd && (nd->flags & LOOKUP_OPEN)) {
                struct cifsFileInfo *pfile_info;
-               /*
-                * cifs_fill_filedata() takes care of setting cifsFileInfo
-                * pointer to file->private_data.
-                */
-               pfile_info = cifs_new_fileinfo(newinode, fileHandle, NULL,
+               struct file *filp;
+
+               filp = lookup_instantiate_filp(nd, direntry, generic_file_open);
+               if (IS_ERR(filp)) {
+                       rc = PTR_ERR(filp);
+                       CIFSSMBClose(xid, tcon, fileHandle);
+                       goto cifs_create_out;
+               }
+
+               pfile_info = cifs_new_fileinfo(newinode, fileHandle, filp,
                                               nd->path.mnt, oflags);
-               if (pfile_info == NULL)
+               if (pfile_info == NULL) {
+                       fput(filp);
+                       CIFSSMBClose(xid, tcon, fileHandle);
                        rc = -ENOMEM;
+               }
        } else {
                CIFSSMBClose(xid, tcon, fileHandle);
        }
@@ -717,15 +728,23 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                        direntry->d_op = &cifs_dentry_ops;
                d_add(direntry, newInode);
                if (posix_open) {
-                       cfile = cifs_new_fileinfo(newInode, fileHandle, NULL,
+                       filp = lookup_instantiate_filp(nd, direntry,
+                                                      generic_file_open);
+                       if (IS_ERR(filp)) {
+                               rc = PTR_ERR(filp);
+                               CIFSSMBClose(xid, pTcon, fileHandle);
+                               goto lookup_out;
+                       }
+
+                       cfile = cifs_new_fileinfo(newInode, fileHandle, filp,
                                                  nd->path.mnt,
                                                  nd->intent.open.flags);
                        if (cfile == NULL) {
+                               fput(filp);
                                CIFSSMBClose(xid, pTcon, fileHandle);
                                rc = -ENOMEM;
                                goto lookup_out;
                        }
-                       filp = lookup_instantiate_filp(nd, direntry, NULL);
                }
                /* since paths are not looked up by component - the parent
                   directories are presumed to be good here */
index 542e0c8..9cbf0f0 100644 (file)
@@ -162,38 +162,6 @@ psx_client_can_cache:
        return 0;
 }
 
-static struct cifsFileInfo *
-cifs_fill_filedata(struct file *file)
-{
-       struct list_head *tmp;
-       struct cifsFileInfo *pCifsFile = NULL;
-       struct cifsInodeInfo *pCifsInode = NULL;
-
-       /* search inode for this file and fill in file->private_data */
-       pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
-       read_lock(&GlobalSMBSeslock);
-       list_for_each(tmp, &pCifsInode->openFileList) {
-               pCifsFile = list_entry(tmp, struct cifsFileInfo, flist);
-               if ((pCifsFile->pfile == NULL) &&
-                   (pCifsFile->pid == current->tgid)) {
-                       /* mode set in cifs_create */
-
-                       /* needed for writepage */
-                       pCifsFile->pfile = file;
-                       file->private_data = pCifsFile;
-                       break;
-               }
-       }
-       read_unlock(&GlobalSMBSeslock);
-
-       if (file->private_data != NULL) {
-               return pCifsFile;
-       } else if ((file->f_flags & O_CREAT) && (file->f_flags & O_EXCL))
-                       cERROR(1, "could not find file instance for "
-                                  "new file %p", file);
-       return NULL;
-}
-
 /* 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,
@@ -256,7 +224,7 @@ int cifs_open(struct inode *inode, struct file *file)
        __u32 oplock;
        struct cifs_sb_info *cifs_sb;
        struct cifsTconInfo *tcon;
-       struct cifsFileInfo *pCifsFile;
+       struct cifsFileInfo *pCifsFile = NULL;
        struct cifsInodeInfo *pCifsInode;
        char *full_path = NULL;
        int desiredAccess;
@@ -270,12 +238,6 @@ int cifs_open(struct inode *inode, struct file *file)
        tcon = cifs_sb->tcon;
 
        pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
-       pCifsFile = cifs_fill_filedata(file);
-       if (pCifsFile) {
-               rc = 0;
-               FreeXid(xid);
-               return rc;
-       }
 
        full_path = build_path_from_dentry(file->f_path.dentry);
        if (full_path == NULL) {
@@ -315,7 +277,6 @@ int cifs_open(struct inode *inode, struct file *file)
                                rc = -ENOMEM;
                                goto out;
                        }
-                       file->private_data = pCifsFile;
 
                        cifs_posix_open_inode_helper(inode, file, pCifsInode,
                                                     oplock, netfid);
@@ -401,8 +362,7 @@ int cifs_open(struct inode *inode, struct file *file)
 
        pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
                                        file->f_flags);
-       file->private_data = pCifsFile;
-       if (file->private_data == NULL) {
+       if (pCifsFile == NULL) {
                rc = -ENOMEM;
                goto out;
        }