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 9 #include <linux/time.h> 10 #include <linux/unistd.h> 11 #include <linux/string.h> 12 #include <linux/slab.h> 13 14 #include <linux/sunrpc/clnt.h> 15 #include <linux/sunrpc/svc.h> 16 #include <linux/lockd/lockd.h> 17 #include <linux/lockd/share.h> 18 19 static inline int 20 nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh) 21 { 22 return share->s_owner.len == oh->len 23 && !memcmp(share->s_owner.data, oh->data, oh->len); 24 } 25 26 __be32 27 nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file, 28 struct nlm_args *argp) 29 { 30 struct nlm_share *share; 31 struct xdr_netobj *oh = &argp->lock.oh; 32 u8 *ohdata; 33 34 for (share = file->f_shares; share; share = share->s_next) { 35 if (share->s_host == host && nlm_cmp_owner(share, oh)) 36 goto update; 37 if ((argp->fsm_access & share->s_mode) 38 || (argp->fsm_mode & share->s_access )) 39 return nlm_lck_denied; 40 } 41 42 share = kmalloc(sizeof(*share) + oh->len, 43 GFP_KERNEL); 44 if (share == NULL) 45 return nlm_lck_denied_nolocks; 46 47 /* Copy owner handle */ 48 ohdata = (u8 *) (share + 1); 49 memcpy(ohdata, oh->data, oh->len); 50 51 share->s_file = file; 52 share->s_host = host; 53 share->s_owner.data = ohdata; 54 share->s_owner.len = oh->len; 55 share->s_next = file->f_shares; 56 file->f_shares = share; 57 58 update: 59 share->s_access = argp->fsm_access; 60 share->s_mode = argp->fsm_mode; 61 return nlm_granted; 62 } 63 64 /* 65 * Delete a share. 66 */ 67 __be32 68 nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file, 69 struct nlm_args *argp) 70 { 71 struct nlm_share *share, **shpp; 72 struct xdr_netobj *oh = &argp->lock.oh; 73 74 for (shpp = &file->f_shares; (share = *shpp) != NULL; 75 shpp = &share->s_next) { 76 if (share->s_host == host && nlm_cmp_owner(share, oh)) { 77 *shpp = share->s_next; 78 kfree(share); 79 return nlm_granted; 80 } 81 } 82 83 /* X/Open spec says return success even if there was no 84 * corresponding share. */ 85 return nlm_granted; 86 } 87 88 /* 89 * Traverse all shares for a given file, and delete 90 * those owned by the given (type of) host 91 */ 92 void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file, 93 nlm_host_match_fn_t match) 94 { 95 struct nlm_share *share, **shpp; 96 97 shpp = &file->f_shares; 98 while ((share = *shpp) != NULL) { 99 if (match(share->s_host, host)) { 100 *shpp = share->s_next; 101 kfree(share); 102 continue; 103 } 104 shpp = &share->s_next; 105 } 106 } 107