Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / udf / symlink.c

diff --git a/kernel/fs/udf/symlink.c b/kernel/fs/udf/symlink.c
new file mode 100644 (file)
index 0000000..8dfbc40
--- /dev/null
+++ b/kernel/fs/udf/symlink.c
@@ -0,0 +1,159 @@
+/*
+ * symlink.c
+ *
+ * PURPOSE
+ *     Symlink handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * COPYRIGHT
+ *     This file is distributed under the terms of the GNU General Public
+ *     License (GPL). Copies of the GPL can be obtained from:
+ *             ftp://prep.ai.mit.edu/pub/gnu/GPL
+ *     Each contributing author retains all rights to their own work.
+ *
+ *  (C) 1998-2001 Ben Fennema
+ *  (C) 1999 Stelias Computing Inc
+ *
+ * HISTORY
+ *
+ *  04/16/99 blf  Created.
+ *
+ */
+
+#include "udfdecl.h"
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/stat.h>
+#include <linux/pagemap.h>
+#include "udf_i.h"
+
+static int udf_pc_to_char(struct super_block *sb, unsigned char *from,
+                         int fromlen, unsigned char *to, int tolen)
+{
+       struct pathComponent *pc;
+       int elen = 0;
+       int comp_len;
+       unsigned char *p = to;
+
+       /* Reserve one byte for terminating \0 */
+       tolen--;
+       while (elen < fromlen) {
+               pc = (struct pathComponent *)(from + elen);
+               elen += sizeof(struct pathComponent);
+               switch (pc->componentType) {
+               case 1:
+                       /*
+                        * Symlink points to some place which should be agreed
+                        * upon between originator and receiver of the media. Ignore.
+                        */
+                       if (pc->lengthComponentIdent > 0) {
+                               elen += pc->lengthComponentIdent;
+                               break;
+                       }
+                       /* Fall through */
+               case 2:
+                       if (tolen == 0)
+                               return -ENAMETOOLONG;
+                       p = to;
+                       *p++ = '/';
+                       tolen--;
+                       break;
+               case 3:
+                       if (tolen < 3)
+                               return -ENAMETOOLONG;
+                       memcpy(p, "../", 3);
+                       p += 3;
+                       tolen -= 3;
+                       break;
+               case 4:
+                       if (tolen < 2)
+                               return -ENAMETOOLONG;
+                       memcpy(p, "./", 2);
+                       p += 2;
+                       tolen -= 2;
+                       /* that would be . - just ignore */
+                       break;
+               case 5:
+                       elen += pc->lengthComponentIdent;
+                       if (elen > fromlen)
+                               return -EIO;
+                       comp_len = udf_get_filename(sb, pc->componentIdent,
+                                                   pc->lengthComponentIdent,
+                                                   p, tolen);
+                       p += comp_len;
+                       tolen -= comp_len;
+                       if (tolen == 0)
+                               return -ENAMETOOLONG;
+                       *p++ = '/';
+                       tolen--;
+                       break;
+               }
+       }
+       if (p > to + 1)
+               p[-1] = '\0';
+       else
+               p[0] = '\0';
+       return 0;
+}
+
+static int udf_symlink_filler(struct file *file, struct page *page)
+{
+       struct inode *inode = page->mapping->host;
+       struct buffer_head *bh = NULL;
+       unsigned char *symlink;
+       int err;
+       unsigned char *p = kmap(page);
+       struct udf_inode_info *iinfo;
+       uint32_t pos;
+
+       /* We don't support symlinks longer than one block */
+       if (inode->i_size > inode->i_sb->s_blocksize) {
+               err = -ENAMETOOLONG;
+               goto out_unmap;
+       }
+
+       iinfo = UDF_I(inode);
+       pos = udf_block_map(inode, 0);
+
+       down_read(&iinfo->i_data_sem);
+       if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
+               symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
+       } else {
+               bh = sb_bread(inode->i_sb, pos);
+
+               if (!bh) {
+                       err = -EIO;
+                       goto out_unlock_inode;
+               }
+
+               symlink = bh->b_data;
+       }
+
+       err = udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p, PAGE_SIZE);
+       brelse(bh);
+       if (err)
+               goto out_unlock_inode;
+
+       up_read(&iinfo->i_data_sem);
+       SetPageUptodate(page);
+       kunmap(page);
+       unlock_page(page);
+       return 0;
+
+out_unlock_inode:
+       up_read(&iinfo->i_data_sem);
+       SetPageError(page);
+out_unmap:
+       kunmap(page);
+       unlock_page(page);
+       return err;
+}
+
+/*
+ * symlinks can't do much...
+ */
+const struct address_space_operations udf_symlink_aops = {
+       .readpage               = udf_symlink_filler,
+};