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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309// SPDX-License-Identifier: GPL-2.0-or-later/* handling of writes to regular files and writing back to the server * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */
#include <linux/backing-dev.h>#include <linux/slab.h>#include <linux/fs.h>#include <linux/pagemap.h>#include <linux/writeback.h>#include <linux/netfs.h>#include <trace/events/netfs.h>#include "internal.h"
/* * completion of write to server */static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsigned int len){ _enter("{%llx:%llu},{%x @%llx}", vnode->fid.vid, vnode->fid.vnode, len, start);
afs_prune_wb_keys(vnode); _leave("");}
/* * Find a key to use for the writeback. We cached the keys used to author the * writes on the vnode. wreq->netfs_priv2 will contain the last writeback key * record used or NULL and we need to start from there if it's set. * wreq->netfs_priv will be set to the key itself or NULL. */static void afs_get_writeback_key(struct netfs_io_request *wreq){ struct afs_wb_key *wbk, *old = wreq->netfs_priv2; struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
key_put(wreq->netfs_priv); wreq->netfs_priv = NULL; wreq->netfs_priv2 = NULL;
spin_lock(&vnode->wb_lock); if (old) wbk = list_next_entry(old, vnode_link); else wbk = list_first_entry(&vnode->wb_keys, struct afs_wb_key, vnode_link);
list_for_each_entry_from(wbk, &vnode->wb_keys, vnode_link) { _debug("wbk %u", key_serial(wbk->key)); if (key_validate(wbk->key) == 0) { refcount_inc(&wbk->usage); wreq->netfs_priv = key_get(wbk->key); wreq->netfs_priv2 = wbk; _debug("USE WB KEY %u", key_serial(wbk->key)); break; } }
spin_unlock(&vnode->wb_lock);
afs_put_wb_key(old);}
static void afs_store_data_success(struct afs_operation *op){ struct afs_vnode *vnode = op->file[0].vnode;
op->ctime = op->file[0].scb.status.mtime_client; afs_vnode_commit_status(op, &op->file[0]); if (!afs_op_error(op)) { afs_pages_written_back(vnode, op->store.pos, op->store.size); afs_stat_v(vnode, n_stores); atomic_long_add(op->store.size, &afs_v2net(vnode)->n_store_bytes); }}
static const struct afs_operation_ops afs_store_data_operation = { .issue_afs_rpc = afs_fs_store_data, .issue_yfs_rpc = yfs_fs_store_data, .success = afs_store_data_success,};
/* * Prepare a subrequest to write to the server. This sets the max_len * parameter. */void afs_prepare_write(struct netfs_io_subrequest *subreq){ struct netfs_io_stream *stream = &subreq->rreq->io_streams[subreq->stream_nr];
//if (test_bit(NETFS_SREQ_RETRYING, &subreq->flags)) // subreq->max_len = 512 * 1024; //else stream->sreq_max_len = 256 * 1024 * 1024;}
/* * Issue a subrequest to write to the server. */static void afs_issue_write_worker(struct work_struct *work){ struct netfs_io_subrequest *subreq = container_of(work, struct netfs_io_subrequest, work); struct netfs_io_request *wreq = subreq->rreq; struct afs_operation *op; struct afs_vnode *vnode = AFS_FS_I(wreq->inode); unsigned long long pos = subreq->start + subreq->transferred; size_t len = subreq->len - subreq->transferred; int ret = -ENOKEY;
_enter("R=%x[%x],%s{%llx:%llu.%u},%llx,%zx", wreq->debug_id, subreq->debug_index, vnode->volume->name, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique, pos, len);
#if 0 // Error injection if (subreq->debug_index == 3) return netfs_write_subrequest_terminated(subreq, -ENOANO);
if (!subreq->retry_count) { set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); return netfs_write_subrequest_terminated(subreq, -EAGAIN); }#endif
op = afs_alloc_operation(wreq->netfs_priv, vnode->volume); if (IS_ERR(op)) return netfs_write_subrequest_terminated(subreq, -EAGAIN);
afs_op_set_vnode(op, 0, vnode); op->file[0].dv_delta = 1; op->file[0].modification = true; op->store.pos = pos; op->store.size = len; op->flags |= AFS_OPERATION_UNINTR; op->ops = &afs_store_data_operation;
afs_begin_vnode_operation(op);
op->store.write_iter = &subreq->io_iter; op->store.i_size = umax(pos + len, netfs_read_remote_i_size(&vnode->netfs.inode)); op->mtime = inode_get_mtime(&vnode->netfs.inode);
afs_wait_for_operation(op); ret = afs_put_operation(op); switch (ret) { case 0: __set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); break; case -EACCES: case -EPERM: case -ENOKEY: case -EKEYEXPIRED: case -EKEYREJECTED: case -EKEYREVOKED: /* If there are more keys we can try, use the retry algorithm * to rotate the keys. */ if (wreq->netfs_priv2) set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); break; }
netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len);}
void afs_issue_write(struct netfs_io_subrequest *subreq){ subreq->work.func = afs_issue_write_worker; if (!queue_work(system_dfl_wq, &subreq->work)) WARN_ON_ONCE(1);}
/* * Writeback calls this when it finds a folio that needs uploading. This isn't * called if writeback only has copy-to-cache to deal with. */void afs_begin_writeback(struct netfs_io_request *wreq){ if (S_ISREG(wreq->inode->i_mode)) afs_get_writeback_key(wreq);}
/* * Prepare to retry the writes in request. Use this to try rotating the * available writeback keys. */void afs_retry_request(struct netfs_io_request *wreq, struct netfs_io_stream *stream){ struct netfs_io_subrequest *subreq = list_first_entry(&stream->subrequests, struct netfs_io_subrequest, rreq_link);
switch (wreq->origin) { case NETFS_READAHEAD: case NETFS_READPAGE: case NETFS_READ_GAPS: case NETFS_READ_SINGLE: case NETFS_READ_FOR_WRITE: case NETFS_UNBUFFERED_READ: case NETFS_DIO_READ: return; default: break; }
switch (subreq->error) { case -EACCES: case -EPERM: case -ENOKEY: case -EKEYEXPIRED: case -EKEYREJECTED: case -EKEYREVOKED: afs_get_writeback_key(wreq); if (!wreq->netfs_priv) stream->failed = true; break; }}
/* * write some of the pending data back to the server */int afs_writepages(struct address_space *mapping, struct writeback_control *wbc){ struct afs_vnode *vnode = AFS_FS_I(mapping->host); int ret;
/* We have to be careful as we can end up racing with setattr() * truncating the pagecache since the caller doesn't take a lock here * to prevent it. */ if (wbc->sync_mode == WB_SYNC_ALL) down_read(&vnode->validate_lock); else if (!down_read_trylock(&vnode->validate_lock)) return 0;
ret = netfs_writepages(mapping, wbc); up_read(&vnode->validate_lock); return ret;}
/* * flush any dirty pages for this process, and check for write errors. * - the return status from this call provides a reliable indication of * whether any write errors occurred for this process. */int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync){ struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); struct afs_file *af = file->private_data; int ret;
_enter("{%llx:%llu},{n=%pD},%d", vnode->fid.vid, vnode->fid.vnode, file, datasync);
ret = afs_validate(vnode, af->key); if (ret < 0) return ret;
return file_write_and_wait_range(file, start, end);}
/* * notification that a previously read-only page is about to become writable * - if it returns an error, the caller will deliver a bus error signal */vm_fault_t afs_page_mkwrite(struct vm_fault *vmf){ struct file *file = vmf->vma->vm_file;
if (afs_validate(AFS_FS_I(file_inode(file)), afs_file_key(file)) < 0) return VM_FAULT_SIGBUS; return netfs_page_mkwrite(vmf, NULL);}
/* * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. */void afs_prune_wb_keys(struct afs_vnode *vnode){ LIST_HEAD(graveyard); struct afs_wb_key *wbk, *tmp;
/* Discard unused keys */ spin_lock(&vnode->wb_lock);
if (!mapping_tagged(&vnode->netfs.inode.i_data, PAGECACHE_TAG_WRITEBACK) && !mapping_tagged(&vnode->netfs.inode.i_data, PAGECACHE_TAG_DIRTY)) { list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { if (refcount_read(&wbk->usage) == 1) list_move(&wbk->vnode_link, &graveyard); } }
spin_unlock(&vnode->wb_lock);
while (!list_empty(&graveyard)) { wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); list_del(&wbk->vnode_link); afs_put_wb_key(wbk); }}