vserver 1.9.3

[linux-2.6.git] / fs / cifs / link.c

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 8deba26..1455810 100644 (file)
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -20,6 +20,7 @@
  */
 #include <linux/fs.h>
 #include <linux/stat.h>
+#include <linux/namei.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
@@ -44,10 +45,18 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
        cifs_sb_target = CIFS_SB(inode->i_sb);
        pTcon = cifs_sb_target->tcon;
 
-/* No need to check for cross device links since server will do that - BB note DFS case in future though (when we may have to check) */
+/* No need to check for cross device links since server will do that
+   BB note DFS case in future though (when we may have to check) */
 
+       down(&inode->i_sb->s_vfs_rename_sem);
        fromName = build_path_from_dentry(old_file);
        toName = build_path_from_dentry(direntry);
+       up(&inode->i_sb->s_vfs_rename_sem);
+       if((fromName == NULL) || (toName == NULL)) {
+               rc = -ENOMEM;
+               goto cifs_hl_exit;
+       }
+
        if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
                rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
                                            cifs_sb_target->local_nls);
@@ -70,6 +79,7 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
        cifsInode = CIFS_I(old_file->d_inode);
        cifsInode->time = 0;    /* will force revalidate to go get info when needed */
 
+cifs_hl_exit:
        if (fromName)
                kfree(fromName);
        if (toName)
@@ -85,24 +95,27 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
        int rc = -EACCES;
        int xid;
        char *full_path = NULL;
-       char * target_path;
+       char * target_path = ERR_PTR(-ENOMEM);
        struct cifs_sb_info *cifs_sb;
        struct cifsTconInfo *pTcon;
 
        xid = GetXid();
+
+       down(&direntry->d_sb->s_vfs_rename_sem);
        full_path = build_path_from_dentry(direntry);
+       up(&direntry->d_sb->s_vfs_rename_sem);
+
+       if (!full_path)
+               goto out_no_free;
+
        cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
        cifs_sb = CIFS_SB(inode->i_sb);
        pTcon = cifs_sb->tcon;
        target_path = kmalloc(PATH_MAX, GFP_KERNEL);
-       if(target_path == NULL) {
-               if (full_path)
-                       kfree(full_path);
-               FreeXid(xid);
-               return -ENOMEM;
+       if (!target_path) {
+               target_path = ERR_PTR(-ENOMEM);
+               goto out;
        }
-       /* can not call the following line due to EFAULT in vfs_readlink which is presumably expecting a user space buffer */
-       /* length = cifs_readlink(direntry,target_path, sizeof(target_path) - 1);    */
 
 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
        if (pTcon->ses->capabilities & CAP_UNIX)
@@ -113,25 +126,25 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
        else {
                /* rc = CIFSSMBQueryReparseLinkInfo */
                /* BB Add code to Query ReparsePoint info */
+               /* BB Add MAC style xsymlink check here if enabled */
        }
-       /* BB Anything else to do to handle recursive links? */
-       /* BB Should we be using page symlink ops here? */
 
        if (rc == 0) {
 
 /* BB Add special case check for Samba DFS symlinks */
 
                target_path[PATH_MAX-1] = 0;
-               rc = vfs_follow_link(nd, target_path);
+       } else {
+               kfree(target_path);
+               target_path = ERR_PTR(rc);
        }
-       /* else EACCESS */
 
-       if (target_path)
-               kfree(target_path);
-       if (full_path)
-               kfree(full_path);
+out:
+       kfree(full_path);
+out_no_free:
        FreeXid(xid);
-       return rc;
+       nd_set_link(nd, target_path);
+       return 0;
 }
 
 int
@@ -149,7 +162,15 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
        cifs_sb = CIFS_SB(inode->i_sb);
        pTcon = cifs_sb->tcon;
 
+       down(&inode->i_sb->s_vfs_rename_sem);
        full_path = build_path_from_dentry(direntry);
+       up(&inode->i_sb->s_vfs_rename_sem);
+
+       if(full_path == NULL) {
+               FreeXid(xid);
+               return -ENOMEM;
+       }
+
        cFYI(1, ("Full path: %s ", full_path));
        cFYI(1, ("symname is %s", symname));
 
@@ -163,10 +184,10 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
        if (rc == 0) {
                if (pTcon->ses->capabilities & CAP_UNIX)
                        rc = cifs_get_inode_info_unix(&newinode, full_path,
-                                                     inode->i_sb);
+                                                     inode->i_sb,xid);
                else
                        rc = cifs_get_inode_info(&newinode, full_path, NULL,
-                                                inode->i_sb);
+                                                inode->i_sb,xid);
 
                if (rc != 0) {
                        cFYI(1,
@@ -185,7 +206,7 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 }
 
 int
-cifs_readlink(struct dentry *direntry, char *pBuffer, int buflen)
+cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
 {
        struct inode *inode = direntry->d_inode;
        int rc = -EACCES;
@@ -204,7 +225,18 @@ cifs_readlink(struct dentry *direntry, char *pBuffer, int buflen)
        xid = GetXid();
        cifs_sb = CIFS_SB(inode->i_sb);
        pTcon = cifs_sb->tcon;
+
+/* BB would it be safe against deadlock to grab this sem 
+      even though rename itself grabs the sem and calls lookup? */
+/*       down(&inode->i_sb->s_vfs_rename_sem);*/
        full_path = build_path_from_dentry(direntry);
+/*       up(&inode->i_sb->s_vfs_rename_sem);*/
+
+       if(full_path == NULL) {
+               FreeXid(xid);
+               return -ENOMEM;
+       }
+
        cFYI(1,
             ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
              full_path, inode, pBuffer, buflen));
@@ -261,10 +293,7 @@ cifs_readlink(struct dentry *direntry, char *pBuffer, int buflen)
                                        if(referrals)
                                                kfree(referrals);
                                        kfree(tmp_path);
-                                       if(referrals) {
-                                               kfree(referrals);
-                                       }
-                               }
+}
                                /* BB add code like else decode referrals then memcpy to
                                  tmpbuffer and free referrals string array BB */
                        }
@@ -290,3 +319,10 @@ cifs_readlink(struct dentry *direntry, char *pBuffer, int buflen)
        FreeXid(xid);
        return rc;
 }
+
+void cifs_put_link(struct dentry *direntry, struct nameidata *nd)
+{
+       char *p = nd_get_link(nd);
+       if (!IS_ERR(p))
+               kfree(p);
+}