NFS: Reduce the stack footprint of nfs_lookup
[safe/jmp/linux-2.6] / fs / cifs / link.c
index eb2fbbe..c1a9d42 100644 (file)
@@ -20,6 +20,7 @@
  */
 #include <linux/fs.h>
 #include <linux/stat.h>
+#include <linux/slab.h>
 #include <linux/namei.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -107,48 +108,48 @@ void *
 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
 {
        struct inode *inode = direntry->d_inode;
-       int rc = -EACCES;
+       int rc = -ENOMEM;
        int xid;
        char *full_path = NULL;
-       char *target_path = ERR_PTR(-ENOMEM);
-       struct cifs_sb_info *cifs_sb;
-       struct cifsTconInfo *pTcon;
+       char *target_path = NULL;
+       struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+       struct cifsTconInfo *tcon = cifs_sb->tcon;
 
        xid = GetXid();
 
-       full_path = build_path_from_dentry(direntry);
+       /*
+        * For now, we just handle symlinks with unix extensions enabled.
+        * Eventually we should handle NTFS reparse points, and MacOS
+        * symlink support. For instance...
+        *
+        * rc = CIFSSMBQueryReparseLinkInfo(...)
+        *
+        * For now, just return -EACCES when the server doesn't support posix
+        * extensions. Note that we still allow querying symlinks when posix
+        * extensions are manually disabled. We could disable these as well
+        * but there doesn't seem to be any harm in allowing the client to
+        * read them.
+        */
+       if (!(tcon->ses->capabilities & CAP_UNIX)) {
+               rc = -EACCES;
+               goto out;
+       }
 
+       full_path = build_path_from_dentry(direntry);
        if (!full_path)
                goto out;
 
        cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
-       cifs_sb = CIFS_SB(inode->i_sb);
-       pTcon = cifs_sb->tcon;
-
-       /* We could change this to:
-               if (pTcon->unix_ext)
-          but there does not seem any point in refusing to
-          get symlink info if we can, even if unix extensions
-          turned off for this mount */
-
-       if (pTcon->ses->capabilities & CAP_UNIX)
-               rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
-                                            &target_path,
-                                            cifs_sb->local_nls);
-       else {
-               /* BB add read reparse point symlink code here */
-               /* rc = CIFSSMBQueryReparseLinkInfo */
-               /* BB Add code to Query ReparsePoint info */
-               /* BB Add MAC style xsymlink check here if enabled */
-       }
 
+       rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
+                                    cifs_sb->local_nls);
+       kfree(full_path);
+out:
        if (rc != 0) {
                kfree(target_path);
                target_path = ERR_PTR(rc);
        }
 
-       kfree(full_path);
-out:
        FreeXid(xid);
        nd_set_link(nd, target_path);
        return NULL;
@@ -172,8 +173,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
        full_path = build_path_from_dentry(direntry);
 
        if (full_path == NULL) {
+               rc = -ENOMEM;
                FreeXid(xid);
-               return -ENOMEM;
+               return rc;
        }
 
        cFYI(1, ("Full path: %s", full_path));
@@ -212,93 +214,6 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
        return rc;
 }
 
-int
-cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
-{
-       struct inode *inode = direntry->d_inode;
-       int rc = -EACCES;
-       int xid;
-       int oplock = 0;
-       struct cifs_sb_info *cifs_sb;
-       struct cifsTconInfo *pTcon;
-       char *full_path = NULL;
-       char *tmpbuffer;
-       int len;
-       __u16 fid;
-
-       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? */
-/*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
-       full_path = build_path_from_dentry(direntry);
-/*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/
-
-       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));
-       if (buflen > PATH_MAX)
-               len = PATH_MAX;
-       else
-               len = buflen;
-       tmpbuffer = kmalloc(len, GFP_KERNEL);
-       if (tmpbuffer == NULL) {
-               kfree(full_path);
-               FreeXid(xid);
-               return -ENOMEM;
-       }
-
-/* BB add read reparse point symlink code and
-       Unix extensions symlink code here BB */
-
-       if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
-               cERROR(1, ("SFU style symlinks not implemented yet"));
-               /* add open and read as in fs/cifs/inode.c */
-       } else {
-               rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
-                               OPEN_REPARSE_POINT, &fid, &oplock, NULL,
-                               cifs_sb->local_nls,
-                               cifs_sb->mnt_cifs_flags &
-                                       CIFS_MOUNT_MAP_SPECIAL_CHR);
-               if (!rc) {
-                       rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
-                               tmpbuffer,
-                               len - 1,
-                               fid,
-                               cifs_sb->local_nls);
-                       if (CIFSSMBClose(xid, pTcon, fid)) {
-                               cFYI(1, ("Error closing junction point "
-                                        "(open for ioctl)"));
-                       }
-                       /* If it is a DFS junction earlier we would have gotten
-                          PATH_NOT_COVERED returned from server so we do
-                          not need to request the DFS info here */
-               }
-       }
-       /* BB Anything else to do to handle recursive links? */
-       /* BB Should we be using page ops here? */
-
-       /* BB null terminate returned string in pBuffer? BB */
-       if (rc == 0) {
-               rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
-               cFYI(1,
-                    ("vfs_readlink called from cifs_readlink returned %d",
-                     rc));
-       }
-
-       kfree(tmpbuffer);
-       kfree(full_path);
-       FreeXid(xid);
-       return rc;
-}
-
 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
 {
        char *p = nd_get_link(nd);