svcshare.c 2.4 KB

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  1. /*
  2. * linux/fs/lockd/svcshare.c
  3. *
  4. * Management of DOS shares.
  5. *
  6. * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
  7. */
  8. #include <linux/time.h>
  9. #include <linux/unistd.h>
  10. #include <linux/string.h>
  11. #include <linux/slab.h>
  12. #include <linux/sunrpc/clnt.h>
  13. #include <linux/sunrpc/svc.h>
  14. #include <linux/lockd/lockd.h>
  15. #include <linux/lockd/share.h>
  16. static inline int
  17. nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
  18. {
  19. return share->s_owner.len == oh->len
  20. && !memcmp(share->s_owner.data, oh->data, oh->len);
  21. }
  22. __be32
  23. nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
  24. struct nlm_args *argp)
  25. {
  26. struct nlm_share *share;
  27. struct xdr_netobj *oh = &argp->lock.oh;
  28. u8 *ohdata;
  29. for (share = file->f_shares; share; share = share->s_next) {
  30. if (share->s_host == host && nlm_cmp_owner(share, oh))
  31. goto update;
  32. if ((argp->fsm_access & share->s_mode)
  33. || (argp->fsm_mode & share->s_access ))
  34. return nlm_lck_denied;
  35. }
  36. share = kmalloc(sizeof(*share) + oh->len,
  37. GFP_KERNEL);
  38. if (share == NULL)
  39. return nlm_lck_denied_nolocks;
  40. /* Copy owner handle */
  41. ohdata = (u8 *) (share + 1);
  42. memcpy(ohdata, oh->data, oh->len);
  43. share->s_file = file;
  44. share->s_host = host;
  45. share->s_owner.data = ohdata;
  46. share->s_owner.len = oh->len;
  47. share->s_next = file->f_shares;
  48. file->f_shares = share;
  49. update:
  50. share->s_access = argp->fsm_access;
  51. share->s_mode = argp->fsm_mode;
  52. return nlm_granted;
  53. }
  54. /*
  55. * Delete a share.
  56. */
  57. __be32
  58. nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
  59. struct nlm_args *argp)
  60. {
  61. struct nlm_share *share, **shpp;
  62. struct xdr_netobj *oh = &argp->lock.oh;
  63. for (shpp = &file->f_shares; (share = *shpp) != 0; shpp = &share->s_next) {
  64. if (share->s_host == host && nlm_cmp_owner(share, oh)) {
  65. *shpp = share->s_next;
  66. kfree(share);
  67. return nlm_granted;
  68. }
  69. }
  70. /* X/Open spec says return success even if there was no
  71. * corresponding share. */
  72. return nlm_granted;
  73. }
  74. /*
  75. * Traverse all shares for a given file, and delete
  76. * those owned by the given (type of) host
  77. */
  78. void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
  79. nlm_host_match_fn_t match)
  80. {
  81. struct nlm_share *share, **shpp;
  82. shpp = &file->f_shares;
  83. while ((share = *shpp) != NULL) {
  84. if (match(share->s_host, host)) {
  85. *shpp = share->s_next;
  86. kfree(share);
  87. continue;
  88. }
  89. shpp = &share->s_next;
  90. }
  91. }