fs/afs/fs_operation.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Fileserver-directed operation handling.
   3  *
   4  * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/fs.h>
  11 #include "internal.h"
  12
  13 static atomic_t afs_operation_debug_counter;
  14
  15 /*
  16  * Create an operation against a volume.
  17  */
  18 struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *volume)
  19 {
  20         struct afs_operation *op;
  21
  22         _enter("");
  23
  24         op = kzalloc(sizeof(*op), GFP_KERNEL);
  25         if (!op)
  26                 return ERR_PTR(-ENOMEM);
  27
  28         if (!key) {
  29                 key = afs_request_key(volume->cell);
  30                 if (IS_ERR(key)) {
  31                         kfree(op);
  32                         return ERR_CAST(key);
  33                 }
  34         } else {
  35                 key_get(key);
  36         }
  37
  38         op->key         = key;
  39         op->volume      = afs_get_volume(volume, afs_volume_trace_get_new_op);
  40         op->net         = volume->cell->net;
  41         op->cb_v_break  = volume->cb_v_break;
  42         op->debug_id    = atomic_inc_return(&afs_operation_debug_counter);
  43         op->error       = -EDESTADDRREQ;
  44         op->ac.error    = SHRT_MAX;
  45
  46         _leave(" = [op=%08x]", op->debug_id);
  47         return op;
  48 }
  49
  50 /*
  51  * Lock the vnode(s) being operated upon.
  52  */
  53 static bool afs_get_io_locks(struct afs_operation *op)
  54 {
  55         struct afs_vnode *vnode = op->file[0].vnode;
  56         struct afs_vnode *vnode2 = op->file[1].vnode;
  57
  58         _enter("");
  59
  60         if (op->flags & AFS_OPERATION_UNINTR) {
  61                 mutex_lock(&vnode->io_lock);
  62                 op->flags |= AFS_OPERATION_LOCK_0;
  63                 _leave(" = t [1]");
  64                 return true;
  65         }
  66
  67         if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2)
  68                 vnode2 = NULL;
  69
  70         if (vnode2 > vnode)
  71                 swap(vnode, vnode2);
  72
  73         if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
  74                 op->error = -ERESTARTSYS;
  75                 op->flags |= AFS_OPERATION_STOP;
  76                 _leave(" = f [I 0]");
  77                 return false;
  78         }
  79         op->flags |= AFS_OPERATION_LOCK_0;
  80
  81         if (vnode2) {
  82                 if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
  83                         op->error = -ERESTARTSYS;
  84                         op->flags |= AFS_OPERATION_STOP;
  85                         mutex_unlock(&vnode->io_lock);
  86                         op->flags &= ~AFS_OPERATION_LOCK_0;
  87                         _leave(" = f [I 1]");
  88                         return false;
  89                 }
  90                 op->flags |= AFS_OPERATION_LOCK_1;
  91         }
  92
  93         _leave(" = t [2]");
  94         return true;
  95 }
  96
  97 static void afs_drop_io_locks(struct afs_operation *op)
  98 {
  99         struct afs_vnode *vnode = op->file[0].vnode;
 100         struct afs_vnode *vnode2 = op->file[1].vnode;
 101
 102         _enter("");
 103
 104         if (op->flags & AFS_OPERATION_LOCK_1)
 105                 mutex_unlock(&vnode2->io_lock);
 106         if (op->flags & AFS_OPERATION_LOCK_0)
 107                 mutex_unlock(&vnode->io_lock);
 108 }
 109
 110 static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp,
 111                               unsigned int index)
 112 {
 113         struct afs_vnode *vnode = vp->vnode;
 114
 115         if (vnode) {
 116                 vp->fid                 = vnode->fid;
 117                 vp->dv_before           = vnode->status.data_version;
 118                 vp->cb_break_before     = afs_calc_vnode_cb_break(vnode);
 119                 if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
 120                         op->flags       |= AFS_OPERATION_CUR_ONLY;
 121         }
 122
 123         if (vp->fid.vnode)
 124                 _debug("PREP[%u] {%llx:%llu.%u}",
 125                        index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
 126 }
 127
 128 /*
 129  * Begin an operation on the fileserver.
 130  *
 131  * Fileserver operations are serialised on the server by vnode, so we serialise
 132  * them here also using the io_lock.
 133  */
 134 bool afs_begin_vnode_operation(struct afs_operation *op)
 135 {
 136         struct afs_vnode *vnode = op->file[0].vnode;
 137
 138         ASSERT(vnode);
 139
 140         _enter("");
 141
 142         if (op->file[0].need_io_lock)
 143                 if (!afs_get_io_locks(op))
 144                         return false;
 145
 146         afs_prepare_vnode(op, &op->file[0], 0);
 147         afs_prepare_vnode(op, &op->file[1], 1);
 148         op->cb_v_break = op->volume->cb_v_break;
 149         _leave(" = true");
 150         return true;
 151 }
 152
 153 /*
 154  * Tidy up a filesystem cursor and unlock the vnode.
 155  */
 156 static void afs_end_vnode_operation(struct afs_operation *op)
 157 {
 158         _enter("");
 159
 160         if (op->error == -EDESTADDRREQ ||
 161             op->error == -EADDRNOTAVAIL ||
 162             op->error == -ENETUNREACH ||
 163             op->error == -EHOSTUNREACH)
 164                 afs_dump_edestaddrreq(op);
 165
 166         afs_drop_io_locks(op);
 167
 168         if (op->error == -ECONNABORTED)
 169                 op->error = afs_abort_to_error(op->ac.abort_code);
 170 }
 171
 172 /*
 173  * Wait for an in-progress operation to complete.
 174  */
 175 void afs_wait_for_operation(struct afs_operation *op)
 176 {
 177         _enter("");
 178
 179         while (afs_select_fileserver(op)) {
 180                 op->cb_s_break = op->server->cb_s_break;
 181                 if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags) &&
 182                     op->ops->issue_yfs_rpc)
 183                         op->ops->issue_yfs_rpc(op);
 184                 else
 185                         op->ops->issue_afs_rpc(op);
 186
 187                 op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
 188         }
 189
 190         switch (op->error) {
 191         case 0:
 192                 _debug("success");
 193                 op->ops->success(op);
 194                 break;
 195         case -ECONNABORTED:
 196                 if (op->ops->aborted)
 197                         op->ops->aborted(op);
 198                 break;
 199         default:
 200                 break;
 201         }
 202
 203         afs_end_vnode_operation(op);
 204
 205         if (op->error == 0 && op->ops->edit_dir) {
 206                 _debug("edit_dir");
 207                 op->ops->edit_dir(op);
 208         }
 209         _leave("");
 210 }
 211
 212 /*
 213  * Dispose of an operation.
 214  */
 215 int afs_put_operation(struct afs_operation *op)
 216 {
 217         int i, ret = op->error;
 218
 219         _enter("op=%08x,%d", op->debug_id, ret);
 220
 221         if (op->ops && op->ops->put)
 222                 op->ops->put(op);
 223         if (op->file[0].put_vnode)
 224                 iput(&op->file[0].vnode->vfs_inode);
 225         if (op->file[1].put_vnode)
 226                 iput(&op->file[1].vnode->vfs_inode);
 227
 228         if (op->more_files) {
 229                 for (i = 0; i < op->nr_files - 2; i++)
 230                         if (op->more_files[i].put_vnode)
 231                                 iput(&op->more_files[i].vnode->vfs_inode);
 232                 kfree(op->more_files);
 233         }
 234
 235         afs_end_cursor(&op->ac);
 236         afs_put_serverlist(op->net, op->server_list);
 237         afs_put_volume(op->net, op->volume, afs_volume_trace_put_put_op);
 238         key_put(op->key);
 239         kfree(op);
 240         return ret;
 241 }
 242
 243 int afs_do_sync_operation(struct afs_operation *op)
 244 {
 245         afs_begin_vnode_operation(op);
 246         afs_wait_for_operation(op);
 247         return afs_put_operation(op);
 248 }