diff options
Diffstat (limited to 'fs/afs/fs_operation.c')
| -rw-r--r-- | fs/afs/fs_operation.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/fs/afs/fs_operation.c b/fs/afs/fs_operation.c new file mode 100644 index 000000000000..f7a768d12141 --- /dev/null +++ b/fs/afs/fs_operation.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Fileserver-directed operation handling. + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include "internal.h" + +static atomic_t afs_operation_debug_counter; + +/* + * Create an operation against a volume. + */ +struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *volume) +{ + struct afs_operation *op; + + _enter(""); + + op = kzalloc(sizeof(*op), GFP_KERNEL); + if (!op) + return ERR_PTR(-ENOMEM); + + if (!key) { + key = afs_request_key(volume->cell); + if (IS_ERR(key)) { + kfree(op); + return ERR_CAST(key); + } + } else { + key_get(key); + } + + op->key = key; + op->volume = afs_get_volume(volume); + op->net = volume->cell->net; + op->cb_v_break = volume->cb_v_break; + op->debug_id = atomic_inc_return(&afs_operation_debug_counter); + op->error = -EDESTADDRREQ; + op->ac.error = SHRT_MAX; + + _leave(" = [op=%08x]", op->debug_id); + return op; +} + +/* + * Lock the vnode(s) being operated upon. + */ +static bool afs_get_io_locks(struct afs_operation *op) +{ + struct afs_vnode *vnode = op->file[0].vnode; + struct afs_vnode *vnode2 = op->file[1].vnode; + + _enter(""); + + if (op->flags & AFS_OPERATION_UNINTR) { + mutex_lock(&vnode->io_lock); + op->flags |= AFS_OPERATION_LOCK_0; + _leave(" = t [1]"); + return true; + } + + if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2) + vnode2 = NULL; + + if (vnode2 > vnode) + swap(vnode, vnode2); + + if (mutex_lock_interruptible(&vnode->io_lock) < 0) { + op->error = -EINTR; + op->flags |= AFS_OPERATION_STOP; + _leave(" = f [I 0]"); + return false; + } + op->flags |= AFS_OPERATION_LOCK_0; + + if (vnode2) { + if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) { + op->error = -EINTR; + op->flags |= AFS_OPERATION_STOP; + mutex_unlock(&vnode->io_lock); + op->flags &= ~AFS_OPERATION_LOCK_0; + _leave(" = f [I 1]"); + return false; + } + op->flags |= AFS_OPERATION_LOCK_1; + } + + _leave(" = t [2]"); + return true; +} + +static void afs_drop_io_locks(struct afs_operation *op) +{ + struct afs_vnode *vnode = op->file[0].vnode; + struct afs_vnode *vnode2 = op->file[1].vnode; + + _enter(""); + + if (op->flags & AFS_OPERATION_LOCK_1) + mutex_unlock(&vnode2->io_lock); + if (op->flags & AFS_OPERATION_LOCK_0) + mutex_unlock(&vnode->io_lock); +} + +static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp, + unsigned int index) +{ + struct afs_vnode *vnode = vp->vnode; + + if (vnode) { + vp->fid = vnode->fid; + vp->dv_before = vnode->status.data_version; + vp->cb_break_before = afs_calc_vnode_cb_break(vnode); + if (vnode->lock_state != AFS_VNODE_LOCK_NONE) + op->flags |= AFS_OPERATION_CUR_ONLY; + } + + if (vp->fid.vnode) + _debug("PREP[%u] {%llx:%llu.%u}", + index, vp->fid.vid, vp->fid.vnode, vp->fid.unique); +} + +/* + * Begin an operation on the fileserver. + * + * Fileserver operations are serialised on the server by vnode, so we serialise + * them here also using the io_lock. + */ +bool afs_begin_vnode_operation(struct afs_operation *op) +{ + struct afs_vnode *vnode = op->file[0].vnode; + + ASSERT(vnode); + + _enter(""); + + if (op->file[0].need_io_lock) + if (!afs_get_io_locks(op)) + return false; + + read_seqlock_excl(&vnode->cb_lock); + op->cbi = afs_get_cb_interest( + rcu_dereference_protected(vnode->cb_interest, + lockdep_is_held(&vnode->cb_lock.lock))); + read_sequnlock_excl(&vnode->cb_lock); + + afs_prepare_vnode(op, &op->file[0], 0); + afs_prepare_vnode(op, &op->file[1], 1); + op->cb_v_break = op->volume->cb_v_break; + _leave(" = true"); + return true; +} + +/* + * Tidy up a filesystem cursor and unlock the vnode. + */ +static void afs_end_vnode_operation(struct afs_operation *op) +{ + _enter(""); + + if (op->error == -EDESTADDRREQ || + op->error == -EADDRNOTAVAIL || + op->error == -ENETUNREACH || + op->error == -EHOSTUNREACH) + afs_dump_edestaddrreq(op); + + afs_drop_io_locks(op); + + if (op->error == -ECONNABORTED) + op->error = afs_abort_to_error(op->ac.abort_code); +} + +/* + * Wait for an in-progress operation to complete. + */ +void afs_wait_for_operation(struct afs_operation *op) +{ + _enter(""); + + while (afs_select_fileserver(op)) { + op->cb_s_break = op->cbi->server->cb_s_break; + if (test_bit(AFS_SERVER_FL_IS_YFS, &op->cbi->server->flags) && + op->ops->issue_yfs_rpc) + op->ops->issue_yfs_rpc(op); + else + op->ops->issue_afs_rpc(op); + + op->error = afs_wait_for_call_to_complete(op->call, &op->ac); + } + + if (op->error == 0) { + _debug("success"); + op->ops->success(op); + } + + afs_end_vnode_operation(op); + + if (op->error == 0 && op->ops->edit_dir) { + _debug("edit_dir"); + op->ops->edit_dir(op); + } + _leave(""); +} + +/* + * Dispose of an operation. + */ +int afs_put_operation(struct afs_operation *op) +{ + int i, ret = op->error; + + _enter("op=%08x,%d", op->debug_id, ret); + + if (op->ops && op->ops->put) + op->ops->put(op); + if (op->file[0].put_vnode) + iput(&op->file[0].vnode->vfs_inode); + if (op->file[1].put_vnode) + iput(&op->file[1].vnode->vfs_inode); + + if (op->more_files) { + for (i = 0; i < op->nr_files - 2; i++) + if (op->more_files[i].put_vnode) + iput(&op->more_files[i].vnode->vfs_inode); + kfree(op->more_files); + } + + afs_end_cursor(&op->ac); + afs_put_cb_interest(op->net, op->cbi); + afs_put_serverlist(op->net, op->server_list); + afs_put_volume(op->net, op->volume); + kfree(op); + return ret; +} + +int afs_do_sync_operation(struct afs_operation *op) +{ + afs_begin_vnode_operation(op); + afs_wait_for_operation(op); + return afs_put_operation(op); +} |