| .. | .. |
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| 21 | 21 | #include "internal.h" |
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| 22 | 22 | |
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| 23 | 23 | /* |
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| 24 | | - * Create volume and callback interests on a server. |
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| 25 | | - */ |
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| 26 | | -static struct afs_cb_interest *afs_create_interest(struct afs_server *server, |
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| 27 | | - struct afs_vnode *vnode) |
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| 28 | | -{ |
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| 29 | | - struct afs_vol_interest *new_vi, *vi; |
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| 30 | | - struct afs_cb_interest *new; |
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| 31 | | - struct hlist_node **pp; |
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| 32 | | - |
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| 33 | | - new_vi = kzalloc(sizeof(struct afs_vol_interest), GFP_KERNEL); |
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| 34 | | - if (!new_vi) |
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| 35 | | - return NULL; |
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| 36 | | - |
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| 37 | | - new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL); |
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| 38 | | - if (!new) { |
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| 39 | | - kfree(new_vi); |
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| 40 | | - return NULL; |
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| 41 | | - } |
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| 42 | | - |
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| 43 | | - new_vi->usage = 1; |
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| 44 | | - new_vi->vid = vnode->volume->vid; |
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| 45 | | - INIT_HLIST_NODE(&new_vi->srv_link); |
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| 46 | | - INIT_HLIST_HEAD(&new_vi->cb_interests); |
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| 47 | | - |
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| 48 | | - refcount_set(&new->usage, 1); |
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| 49 | | - new->sb = vnode->vfs_inode.i_sb; |
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| 50 | | - new->vid = vnode->volume->vid; |
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| 51 | | - new->server = afs_get_server(server); |
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| 52 | | - INIT_HLIST_NODE(&new->cb_vlink); |
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| 53 | | - |
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| 54 | | - write_lock(&server->cb_break_lock); |
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| 55 | | - |
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| 56 | | - for (pp = &server->cb_volumes.first; *pp; pp = &(*pp)->next) { |
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| 57 | | - vi = hlist_entry(*pp, struct afs_vol_interest, srv_link); |
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| 58 | | - if (vi->vid < new_vi->vid) |
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| 59 | | - continue; |
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| 60 | | - if (vi->vid > new_vi->vid) |
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| 61 | | - break; |
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| 62 | | - vi->usage++; |
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| 63 | | - goto found_vi; |
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| 64 | | - } |
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| 65 | | - |
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| 66 | | - new_vi->srv_link.pprev = pp; |
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| 67 | | - new_vi->srv_link.next = *pp; |
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| 68 | | - if (*pp) |
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| 69 | | - (*pp)->pprev = &new_vi->srv_link.next; |
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| 70 | | - *pp = &new_vi->srv_link; |
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| 71 | | - vi = new_vi; |
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| 72 | | - new_vi = NULL; |
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| 73 | | -found_vi: |
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| 74 | | - |
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| 75 | | - new->vol_interest = vi; |
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| 76 | | - hlist_add_head(&new->cb_vlink, &vi->cb_interests); |
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| 77 | | - |
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| 78 | | - write_unlock(&server->cb_break_lock); |
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| 79 | | - kfree(new_vi); |
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| 80 | | - return new; |
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| 81 | | -} |
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| 82 | | - |
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| 83 | | -/* |
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| 84 | | - * Set up an interest-in-callbacks record for a volume on a server and |
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| 85 | | - * register it with the server. |
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| 86 | | - * - Called with vnode->io_lock held. |
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| 87 | | - */ |
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| 88 | | -int afs_register_server_cb_interest(struct afs_vnode *vnode, |
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| 89 | | - struct afs_server_list *slist, |
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| 90 | | - unsigned int index) |
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| 91 | | -{ |
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| 92 | | - struct afs_server_entry *entry = &slist->servers[index]; |
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| 93 | | - struct afs_cb_interest *cbi, *vcbi, *new, *old; |
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| 94 | | - struct afs_server *server = entry->server; |
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| 95 | | - |
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| 96 | | -again: |
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| 97 | | - if (vnode->cb_interest && |
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| 98 | | - likely(vnode->cb_interest == entry->cb_interest)) |
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| 99 | | - return 0; |
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| 100 | | - |
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| 101 | | - read_lock(&slist->lock); |
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| 102 | | - cbi = afs_get_cb_interest(entry->cb_interest); |
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| 103 | | - read_unlock(&slist->lock); |
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| 104 | | - |
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| 105 | | - vcbi = vnode->cb_interest; |
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| 106 | | - if (vcbi) { |
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| 107 | | - if (vcbi == cbi) { |
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| 108 | | - afs_put_cb_interest(afs_v2net(vnode), cbi); |
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| 109 | | - return 0; |
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| 110 | | - } |
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| 111 | | - |
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| 112 | | - /* Use a new interest in the server list for the same server |
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| 113 | | - * rather than an old one that's still attached to a vnode. |
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| 114 | | - */ |
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| 115 | | - if (cbi && vcbi->server == cbi->server) { |
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| 116 | | - write_seqlock(&vnode->cb_lock); |
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| 117 | | - old = vnode->cb_interest; |
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| 118 | | - vnode->cb_interest = cbi; |
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| 119 | | - write_sequnlock(&vnode->cb_lock); |
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| 120 | | - afs_put_cb_interest(afs_v2net(vnode), old); |
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| 121 | | - return 0; |
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| 122 | | - } |
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| 123 | | - |
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| 124 | | - /* Re-use the one attached to the vnode. */ |
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| 125 | | - if (!cbi && vcbi->server == server) { |
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| 126 | | - write_lock(&slist->lock); |
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| 127 | | - if (entry->cb_interest) { |
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| 128 | | - write_unlock(&slist->lock); |
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| 129 | | - afs_put_cb_interest(afs_v2net(vnode), cbi); |
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| 130 | | - goto again; |
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| 131 | | - } |
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| 132 | | - |
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| 133 | | - entry->cb_interest = cbi; |
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| 134 | | - write_unlock(&slist->lock); |
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| 135 | | - return 0; |
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| 136 | | - } |
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| 137 | | - } |
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| 138 | | - |
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| 139 | | - if (!cbi) { |
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| 140 | | - new = afs_create_interest(server, vnode); |
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| 141 | | - if (!new) |
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| 142 | | - return -ENOMEM; |
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| 143 | | - |
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| 144 | | - write_lock(&slist->lock); |
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| 145 | | - if (!entry->cb_interest) { |
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| 146 | | - entry->cb_interest = afs_get_cb_interest(new); |
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| 147 | | - cbi = new; |
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| 148 | | - new = NULL; |
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| 149 | | - } else { |
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| 150 | | - cbi = afs_get_cb_interest(entry->cb_interest); |
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| 151 | | - } |
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| 152 | | - write_unlock(&slist->lock); |
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| 153 | | - afs_put_cb_interest(afs_v2net(vnode), new); |
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| 154 | | - } |
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| 155 | | - |
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| 156 | | - ASSERT(cbi); |
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| 157 | | - |
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| 158 | | - /* Change the server the vnode is using. This entails scrubbing any |
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| 159 | | - * interest the vnode had in the previous server it was using. |
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| 160 | | - */ |
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| 161 | | - write_seqlock(&vnode->cb_lock); |
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| 162 | | - |
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| 163 | | - old = vnode->cb_interest; |
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| 164 | | - vnode->cb_interest = cbi; |
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| 165 | | - vnode->cb_s_break = cbi->server->cb_s_break; |
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| 166 | | - vnode->cb_v_break = vnode->volume->cb_v_break; |
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| 167 | | - clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); |
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| 168 | | - |
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| 169 | | - write_sequnlock(&vnode->cb_lock); |
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| 170 | | - afs_put_cb_interest(afs_v2net(vnode), old); |
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| 171 | | - return 0; |
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| 172 | | -} |
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| 173 | | - |
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| 174 | | -/* |
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| 175 | | - * Remove an interest on a server. |
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| 176 | | - */ |
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| 177 | | -void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi) |
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| 178 | | -{ |
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| 179 | | - struct afs_vol_interest *vi; |
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| 180 | | - |
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| 181 | | - if (cbi && refcount_dec_and_test(&cbi->usage)) { |
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| 182 | | - if (!hlist_unhashed(&cbi->cb_vlink)) { |
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| 183 | | - write_lock(&cbi->server->cb_break_lock); |
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| 184 | | - |
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| 185 | | - hlist_del_init(&cbi->cb_vlink); |
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| 186 | | - vi = cbi->vol_interest; |
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| 187 | | - cbi->vol_interest = NULL; |
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| 188 | | - if (--vi->usage == 0) |
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| 189 | | - hlist_del(&vi->srv_link); |
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| 190 | | - else |
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| 191 | | - vi = NULL; |
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| 192 | | - |
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| 193 | | - write_unlock(&cbi->server->cb_break_lock); |
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| 194 | | - kfree(vi); |
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| 195 | | - afs_put_server(net, cbi->server); |
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| 196 | | - } |
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| 197 | | - kfree(cbi); |
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| 198 | | - } |
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| 199 | | -} |
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| 200 | | - |
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| 201 | | -/* |
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| 202 | | - * allow the fileserver to request callback state (re-)initialisation |
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| 24 | + * Allow the fileserver to request callback state (re-)initialisation. |
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| 25 | + * Unfortunately, UUIDs are not guaranteed unique. |
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| 203 | 26 | */ |
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| 204 | 27 | void afs_init_callback_state(struct afs_server *server) |
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| 205 | 28 | { |
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| 206 | | - if (!test_and_clear_bit(AFS_SERVER_FL_NEW, &server->flags)) |
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| 29 | + rcu_read_lock(); |
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| 30 | + do { |
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| 207 | 31 | server->cb_s_break++; |
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| 32 | + server = rcu_dereference(server->uuid_next); |
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| 33 | + } while (0); |
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| 34 | + rcu_read_unlock(); |
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| 208 | 35 | } |
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| 209 | 36 | |
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| 210 | 37 | /* |
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| 211 | 38 | * actually break a callback |
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| 212 | 39 | */ |
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| 213 | | -void afs_break_callback(struct afs_vnode *vnode) |
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| 40 | +void __afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason) |
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| 214 | 41 | { |
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| 215 | 42 | _enter(""); |
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| 216 | | - |
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| 217 | | - write_seqlock(&vnode->cb_lock); |
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| 218 | 43 | |
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| 219 | 44 | clear_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); |
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| 220 | 45 | if (test_and_clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { |
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| .. | .. |
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| 223 | 48 | |
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| 224 | 49 | if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB) |
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| 225 | 50 | afs_lock_may_be_available(vnode); |
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| 226 | | - } |
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| 227 | 51 | |
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| 52 | + trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, true); |
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| 53 | + } else { |
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| 54 | + trace_afs_cb_break(&vnode->fid, vnode->cb_break, reason, false); |
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| 55 | + } |
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| 56 | +} |
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| 57 | + |
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| 58 | +void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason) |
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| 59 | +{ |
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| 60 | + write_seqlock(&vnode->cb_lock); |
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| 61 | + __afs_break_callback(vnode, reason); |
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| 228 | 62 | write_sequnlock(&vnode->cb_lock); |
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| 63 | +} |
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| 64 | + |
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| 65 | +/* |
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| 66 | + * Look up a volume by volume ID under RCU conditions. |
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| 67 | + */ |
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| 68 | +static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell, |
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| 69 | + afs_volid_t vid) |
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| 70 | +{ |
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| 71 | + struct afs_volume *volume = NULL; |
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| 72 | + struct rb_node *p; |
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| 73 | + int seq = 0; |
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| 74 | + |
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| 75 | + do { |
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| 76 | + /* Unfortunately, rbtree walking doesn't give reliable results |
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| 77 | + * under just the RCU read lock, so we have to check for |
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| 78 | + * changes. |
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| 79 | + */ |
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| 80 | + read_seqbegin_or_lock(&cell->volume_lock, &seq); |
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| 81 | + |
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| 82 | + p = rcu_dereference_raw(cell->volumes.rb_node); |
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| 83 | + while (p) { |
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| 84 | + volume = rb_entry(p, struct afs_volume, cell_node); |
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| 85 | + |
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| 86 | + if (volume->vid < vid) |
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| 87 | + p = rcu_dereference_raw(p->rb_left); |
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| 88 | + else if (volume->vid > vid) |
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| 89 | + p = rcu_dereference_raw(p->rb_right); |
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| 90 | + else |
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| 91 | + break; |
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| 92 | + volume = NULL; |
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| 93 | + } |
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| 94 | + |
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| 95 | + } while (need_seqretry(&cell->volume_lock, seq)); |
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| 96 | + |
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| 97 | + done_seqretry(&cell->volume_lock, seq); |
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| 98 | + return volume; |
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| 229 | 99 | } |
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| 230 | 100 | |
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| 231 | 101 | /* |
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| .. | .. |
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| 234 | 104 | * - the backing file is changed |
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| 235 | 105 | * - a lock is released |
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| 236 | 106 | */ |
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| 237 | | -static void afs_break_one_callback(struct afs_server *server, |
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| 107 | +static void afs_break_one_callback(struct afs_volume *volume, |
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| 238 | 108 | struct afs_fid *fid) |
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| 239 | 109 | { |
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| 240 | | - struct afs_vol_interest *vi; |
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| 241 | | - struct afs_cb_interest *cbi; |
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| 242 | | - struct afs_iget_data data; |
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| 110 | + struct super_block *sb; |
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| 243 | 111 | struct afs_vnode *vnode; |
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| 244 | 112 | struct inode *inode; |
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| 245 | 113 | |
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| 246 | | - read_lock(&server->cb_break_lock); |
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| 247 | | - hlist_for_each_entry(vi, &server->cb_volumes, srv_link) { |
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| 248 | | - if (vi->vid < fid->vid) |
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| 249 | | - continue; |
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| 250 | | - if (vi->vid > fid->vid) { |
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| 251 | | - vi = NULL; |
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| 252 | | - break; |
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| 253 | | - } |
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| 254 | | - //atomic_inc(&vi->usage); |
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| 255 | | - break; |
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| 114 | + if (fid->vnode == 0 && fid->unique == 0) { |
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| 115 | + /* The callback break applies to an entire volume. */ |
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| 116 | + write_lock(&volume->cb_v_break_lock); |
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| 117 | + volume->cb_v_break++; |
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| 118 | + trace_afs_cb_break(fid, volume->cb_v_break, |
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| 119 | + afs_cb_break_for_volume_callback, false); |
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| 120 | + write_unlock(&volume->cb_v_break_lock); |
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| 121 | + return; |
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| 256 | 122 | } |
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| 123 | + |
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| 124 | + /* See if we can find a matching inode - even an I_NEW inode needs to |
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| 125 | + * be marked as it can have its callback broken before we finish |
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| 126 | + * setting up the local inode. |
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| 127 | + */ |
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| 128 | + sb = rcu_dereference(volume->sb); |
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| 129 | + if (!sb) |
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| 130 | + return; |
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| 131 | + |
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| 132 | + inode = find_inode_rcu(sb, fid->vnode, afs_ilookup5_test_by_fid, fid); |
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| 133 | + if (inode) { |
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| 134 | + vnode = AFS_FS_I(inode); |
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| 135 | + afs_break_callback(vnode, afs_cb_break_for_callback); |
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| 136 | + } else { |
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| 137 | + trace_afs_cb_miss(fid, afs_cb_break_for_callback); |
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| 138 | + } |
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| 139 | +} |
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| 140 | + |
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| 141 | +static void afs_break_some_callbacks(struct afs_server *server, |
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| 142 | + struct afs_callback_break *cbb, |
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| 143 | + size_t *_count) |
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| 144 | +{ |
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| 145 | + struct afs_callback_break *residue = cbb; |
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| 146 | + struct afs_volume *volume; |
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| 147 | + afs_volid_t vid = cbb->fid.vid; |
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| 148 | + size_t i; |
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| 149 | + |
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| 150 | + volume = afs_lookup_volume_rcu(server->cell, vid); |
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| 257 | 151 | |
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| 258 | 152 | /* TODO: Find all matching volumes if we couldn't match the server and |
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| 259 | 153 | * break them anyway. |
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| 260 | 154 | */ |
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| 261 | | - if (!vi) |
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| 262 | | - goto out; |
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| 263 | 155 | |
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| 264 | | - /* Step through all interested superblocks. There may be more than one |
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| 265 | | - * because of cell aliasing. |
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| 266 | | - */ |
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| 267 | | - hlist_for_each_entry(cbi, &vi->cb_interests, cb_vlink) { |
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| 268 | | - if (fid->vnode == 0 && fid->unique == 0) { |
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| 269 | | - /* The callback break applies to an entire volume. */ |
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| 270 | | - struct afs_super_info *as = AFS_FS_S(cbi->sb); |
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| 271 | | - struct afs_volume *volume = as->volume; |
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| 272 | | - |
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| 273 | | - write_lock(&volume->cb_v_break_lock); |
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| 274 | | - volume->cb_v_break++; |
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| 275 | | - write_unlock(&volume->cb_v_break_lock); |
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| 156 | + for (i = *_count; i > 0; cbb++, i--) { |
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| 157 | + if (cbb->fid.vid == vid) { |
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| 158 | + _debug("- Fid { vl=%08llx n=%llu u=%u }", |
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| 159 | + cbb->fid.vid, |
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| 160 | + cbb->fid.vnode, |
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| 161 | + cbb->fid.unique); |
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| 162 | + --*_count; |
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| 163 | + if (volume) |
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| 164 | + afs_break_one_callback(volume, &cbb->fid); |
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| 276 | 165 | } else { |
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| 277 | | - data.volume = NULL; |
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| 278 | | - data.fid = *fid; |
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| 279 | | - inode = ilookup5_nowait(cbi->sb, fid->vnode, |
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| 280 | | - afs_iget5_test, &data); |
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| 281 | | - if (inode) { |
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| 282 | | - vnode = AFS_FS_I(inode); |
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| 283 | | - afs_break_callback(vnode); |
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| 284 | | - iput(inode); |
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| 285 | | - } |
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| 166 | + *residue++ = *cbb; |
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| 286 | 167 | } |
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| 287 | 168 | } |
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| 288 | | - |
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| 289 | | -out: |
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| 290 | | - read_unlock(&server->cb_break_lock); |
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| 291 | 169 | } |
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| 292 | 170 | |
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| 293 | 171 | /* |
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| .. | .. |
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| 299 | 177 | _enter("%p,%zu,", server, count); |
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| 300 | 178 | |
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| 301 | 179 | ASSERT(server != NULL); |
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| 302 | | - ASSERTCMP(count, <=, AFSCBMAX); |
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| 303 | 180 | |
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| 304 | | - /* TODO: Sort the callback break list by volume ID */ |
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| 181 | + rcu_read_lock(); |
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| 305 | 182 | |
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| 306 | | - for (; count > 0; callbacks++, count--) { |
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| 307 | | - _debug("- Fid { vl=%08x n=%u u=%u } CB { v=%u x=%u t=%u }", |
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| 308 | | - callbacks->fid.vid, |
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| 309 | | - callbacks->fid.vnode, |
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| 310 | | - callbacks->fid.unique, |
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| 311 | | - callbacks->cb.version, |
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| 312 | | - callbacks->cb.expiry, |
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| 313 | | - callbacks->cb.type |
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| 314 | | - ); |
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| 315 | | - afs_break_one_callback(server, &callbacks->fid); |
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| 316 | | - } |
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| 183 | + while (count > 0) |
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| 184 | + afs_break_some_callbacks(server, callbacks, &count); |
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| 317 | 185 | |
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| 318 | | - _leave(""); |
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| 186 | + rcu_read_unlock(); |
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| 319 | 187 | return; |
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| 320 | | -} |
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| 321 | | - |
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| 322 | | -/* |
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| 323 | | - * Clear the callback interests in a server list. |
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| 324 | | - */ |
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| 325 | | -void afs_clear_callback_interests(struct afs_net *net, struct afs_server_list *slist) |
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| 326 | | -{ |
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| 327 | | - int i; |
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| 328 | | - |
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| 329 | | - for (i = 0; i < slist->nr_servers; i++) { |
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| 330 | | - afs_put_cb_interest(net, slist->servers[i].cb_interest); |
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| 331 | | - slist->servers[i].cb_interest = NULL; |
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| 332 | | - } |
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| 333 | 188 | } |
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