vxfs_immed.c 2.6 KB

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  1. /*
  2. * Copyright (c) 2000-2001 Christoph Hellwig.
  3. * All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions, and the following disclaimer,
  10. * without modification.
  11. * 2. The name of the author may not be used to endorse or promote products
  12. * derived from this software without specific prior written permission.
  13. *
  14. * Alternatively, this software may be distributed under the terms of the
  15. * GNU General Public License ("GPL").
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21. * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27. * SUCH DAMAGE.
  28. */
  29. /*
  30. * Veritas filesystem driver - support for 'immed' inodes.
  31. */
  32. #include <linux/fs.h>
  33. #include <linux/pagemap.h>
  34. #include "vxfs.h"
  35. #include "vxfs_extern.h"
  36. #include "vxfs_inode.h"
  37. static int vxfs_immed_readpage(struct file *, struct page *);
  38. /*
  39. * Address space operations for immed files and directories.
  40. */
  41. const struct address_space_operations vxfs_immed_aops = {
  42. .readpage = vxfs_immed_readpage,
  43. };
  44. /**
  45. * vxfs_immed_readpage - read part of an immed inode into pagecache
  46. * @file: file context (unused)
  47. * @page: page frame to fill in.
  48. *
  49. * Description:
  50. * vxfs_immed_readpage reads a part of the immed area of the
  51. * file that hosts @pp into the pagecache.
  52. *
  53. * Returns:
  54. * Zero on success, else a negative error code.
  55. *
  56. * Locking status:
  57. * @page is locked and will be unlocked.
  58. */
  59. static int
  60. vxfs_immed_readpage(struct file *fp, struct page *pp)
  61. {
  62. struct vxfs_inode_info *vip = VXFS_INO(pp->mapping->host);
  63. u_int64_t offset = (u_int64_t)pp->index << PAGE_CACHE_SHIFT;
  64. caddr_t kaddr;
  65. kaddr = kmap(pp);
  66. memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_CACHE_SIZE);
  67. kunmap(pp);
  68. flush_dcache_page(pp);
  69. SetPageUptodate(pp);
  70. unlock_page(pp);
  71. return 0;
  72. }