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netfs: Remove the old writeback code

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Remove the old writeback code.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
This commit is contained in:
David Howells 2024-03-08 12:36:05 +00:00
parent 2df86547b2
commit c245868524
4 changed files with 0 additions and 1180 deletions
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34
fs/9p/vfs_addr.c
View file

@ -60,40 +60,6 @@ static void v9fs_issue_write(struct netfs_io_subrequest *subreq)
netfs_write_subrequest_terminated(subreq, len ?: err, false);
}
#if 0 // TODO: Remove
static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq)
{
struct p9_fid *fid = subreq->rreq->netfs_priv;
int err, len;
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
netfs_write_subrequest_terminated(subreq, len ?: err, false);
}
static void v9fs_upload_to_server_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
v9fs_upload_to_server(subreq);
}
/*
* Set up write requests for a writeback slice. We need to add a write request
* for each write we want to make.
*/
static void v9fs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
{
struct netfs_io_subrequest *subreq;
subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
start, len, v9fs_upload_to_server_worker);
if (subreq)
netfs_queue_write_request(subreq);
}
#endif
/**
* v9fs_issue_read - Issue a read from 9P
* @subreq: The read to make

40
fs/afs/write.c
View file

@ -156,46 +156,6 @@ static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t
return afs_put_operation(op);
}
#if 0 // TODO: Remove
static void afs_upload_to_server(struct netfs_io_subrequest *subreq)
{
struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
ssize_t ret;
_enter("%x[%x],%zx",
subreq->rreq->debug_id, subreq->debug_index, subreq->io_iter.count);
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
ret = afs_store_data(vnode, &subreq->io_iter, subreq->start);
netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len,
false);
}
static void afs_upload_to_server_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
afs_upload_to_server(subreq);
}
/*
* Set up write requests for a writeback slice. We need to add a write request
* for each write we want to make.
*/
void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
{
struct netfs_io_subrequest *subreq;
_enter("%x,%llx-%llx", wreq->debug_id, start, start + len);
subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
start, len, afs_upload_to_server_worker);
if (subreq)
netfs_queue_write_request(subreq);
}
#endif
/*
* 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.

629
fs/netfs/buffered_write.c
View file

@ -573,632 +573,3 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
return ret;
}
EXPORT_SYMBOL(netfs_page_mkwrite);
#if 0 // TODO: Remove
/*
* Kill all the pages in the given range
*/
static void netfs_kill_pages(struct address_space *mapping,
loff_t start, loff_t len)
{
struct folio *folio;
pgoff_t index = start / PAGE_SIZE;
pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
_enter("%llx-%llx", start, start + len - 1);
do {
_debug("kill %lx (to %lx)", index, last);
folio = filemap_get_folio(mapping, index);
if (IS_ERR(folio)) {
next = index + 1;
continue;
}
next = folio_next_index(folio);
trace_netfs_folio(folio, netfs_folio_trace_kill);
folio_clear_uptodate(folio);
folio_end_writeback(folio);
folio_lock(folio);
generic_error_remove_folio(mapping, folio);
folio_unlock(folio);
folio_put(folio);
} while (index = next, index <= last);
_leave("");
}
/*
* Redirty all the pages in a given range.
*/
static void netfs_redirty_pages(struct address_space *mapping,
loff_t start, loff_t len)
{
struct folio *folio;
pgoff_t index = start / PAGE_SIZE;
pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
_enter("%llx-%llx", start, start + len - 1);
do {
_debug("redirty %llx @%llx", len, start);
folio = filemap_get_folio(mapping, index);
if (IS_ERR(folio)) {
next = index + 1;
continue;
}
next = folio_next_index(folio);
trace_netfs_folio(folio, netfs_folio_trace_redirty);
filemap_dirty_folio(mapping, folio);
folio_end_writeback(folio);
folio_put(folio);
} while (index = next, index <= last);
balance_dirty_pages_ratelimited(mapping);
_leave("");
}
/*
* Completion of write to server
*/
static void netfs_pages_written_back(struct netfs_io_request *wreq)
{
struct address_space *mapping = wreq->mapping;
struct netfs_folio *finfo;
struct netfs_group *group = NULL;
struct folio *folio;
pgoff_t last;
int gcount = 0;
XA_STATE(xas, &mapping->i_pages, wreq->start / PAGE_SIZE);
_enter("%llx-%llx", wreq->start, wreq->start + wreq->len);
rcu_read_lock();
last = (wreq->start + wreq->len - 1) / PAGE_SIZE;
xas_for_each(&xas, folio, last) {
WARN(!folio_test_writeback(folio),
"bad %llx @%llx page %lx %lx\n",
wreq->len, wreq->start, folio->index, last);
if ((finfo = netfs_folio_info(folio))) {
/* Streaming writes cannot be redirtied whilst under
* writeback, so discard the streaming record.
*/
folio_detach_private(folio);
group = finfo->netfs_group;
gcount++;
trace_netfs_folio(folio, netfs_folio_trace_clear_s);
kfree(finfo);
} else if ((group = netfs_folio_group(folio))) {
/* Need to detach the group pointer if the page didn't
* get redirtied. If it has been redirtied, then it
* must be within the same group.
*/
if (folio_test_dirty(folio)) {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
goto end_wb;
}
if (folio_trylock(folio)) {
if (!folio_test_dirty(folio)) {
folio_detach_private(folio);
gcount++;
if (group == NETFS_FOLIO_COPY_TO_CACHE)
trace_netfs_folio(folio,
netfs_folio_trace_end_copy);
else
trace_netfs_folio(folio, netfs_folio_trace_clear_g);
} else {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
}
folio_unlock(folio);
goto end_wb;
}
xas_pause(&xas);
rcu_read_unlock();
folio_lock(folio);
if (!folio_test_dirty(folio)) {
folio_detach_private(folio);
gcount++;
trace_netfs_folio(folio, netfs_folio_trace_clear_g);
} else {
trace_netfs_folio(folio, netfs_folio_trace_redirtied);
}
folio_unlock(folio);
rcu_read_lock();
} else {
trace_netfs_folio(folio, netfs_folio_trace_clear);
}
end_wb:
xas_advance(&xas, folio_next_index(folio) - 1);
folio_end_writeback(folio);
}
rcu_read_unlock();
netfs_put_group_many(group, gcount);
_leave("");
}
/*
* Deal with the disposition of the folios that are under writeback to close
* out the operation.
*/
static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq)
{
struct address_space *mapping = wreq->mapping;
_enter("");
switch (wreq->error) {
case 0:
netfs_pages_written_back(wreq);
break;
default:
pr_notice("R=%08x Unexpected error %d\n", wreq->debug_id, wreq->error);
fallthrough;
case -EACCES:
case -EPERM:
case -ENOKEY:
case -EKEYEXPIRED:
case -EKEYREJECTED:
case -EKEYREVOKED:
case -ENETRESET:
case -EDQUOT:
case -ENOSPC:
netfs_redirty_pages(mapping, wreq->start, wreq->len);
break;
case -EROFS:
case -EIO:
case -EREMOTEIO:
case -EFBIG:
case -ENOENT:
case -ENOMEDIUM:
case -ENXIO:
netfs_kill_pages(mapping, wreq->start, wreq->len);
break;
}
if (wreq->error)
mapping_set_error(mapping, wreq->error);
if (wreq->netfs_ops->done)
wreq->netfs_ops->done(wreq);
}
/*
* Extend the region to be written back to include subsequent contiguously
* dirty pages if possible, but don't sleep while doing so.
*
* If this page holds new content, then we can include filler zeros in the
* writeback.
*/
static void netfs_extend_writeback(struct address_space *mapping,
struct netfs_group *group,
struct xa_state *xas,
long *_count,
loff_t start,
loff_t max_len,
size_t *_len,
size_t *_top)
{
struct netfs_folio *finfo;
struct folio_batch fbatch;
struct folio *folio;
unsigned int i;
pgoff_t index = (start + *_len) / PAGE_SIZE;
size_t len;
void *priv;
bool stop = true;
folio_batch_init(&fbatch);
do {
/* Firstly, we gather up a batch of contiguous dirty pages
* under the RCU read lock - but we can't clear the dirty flags
* there if any of those pages are mapped.
*/
rcu_read_lock();
xas_for_each(xas, folio, ULONG_MAX) {
stop = true;
if (xas_retry(xas, folio))
continue;
if (xa_is_value(folio))
break;
if (folio->index != index) {
xas_reset(xas);
break;
}
if (!folio_try_get_rcu(folio)) {
xas_reset(xas);
continue;
}
/* Has the folio moved or been split? */
if (unlikely(folio != xas_reload(xas))) {
folio_put(folio);
xas_reset(xas);
break;
}
if (!folio_trylock(folio)) {
folio_put(folio);
xas_reset(xas);
break;
}
if (!folio_test_dirty(folio) ||
folio_test_writeback(folio)) {
folio_unlock(folio);
folio_put(folio);
xas_reset(xas);
break;
}
stop = false;
len = folio_size(folio);
priv = folio_get_private(folio);
if ((const struct netfs_group *)priv != group) {
stop = true;
finfo = netfs_folio_info(folio);
if (!finfo ||
finfo->netfs_group != group ||
finfo->dirty_offset > 0) {
folio_unlock(folio);
folio_put(folio);
xas_reset(xas);
break;
}
len = finfo->dirty_len;
}
*_top += folio_size(folio);
index += folio_nr_pages(folio);
*_count -= folio_nr_pages(folio);
*_len += len;
if (*_len >= max_len || *_count <= 0)
stop = true;
if (!folio_batch_add(&fbatch, folio))
break;
if (stop)
break;
}
xas_pause(xas);
rcu_read_unlock();
/* Now, if we obtained any folios, we can shift them to being
* writable and mark them for caching.
*/
if (!folio_batch_count(&fbatch))
break;
for (i = 0; i < folio_batch_count(&fbatch); i++) {
folio = fbatch.folios[i];
if (group == NETFS_FOLIO_COPY_TO_CACHE)
trace_netfs_folio(folio, netfs_folio_trace_copy_plus);
else
trace_netfs_folio(folio, netfs_folio_trace_store_plus);
if (!folio_clear_dirty_for_io(folio))
BUG();
folio_start_writeback(folio);
folio_unlock(folio);
}
folio_batch_release(&fbatch);
cond_resched();
} while (!stop);
}
/*
* Synchronously write back the locked page and any subsequent non-locked dirty
* pages.
*/
static ssize_t netfs_write_back_from_locked_folio(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
struct xa_state *xas,
struct folio *folio,
unsigned long long start,
unsigned long long end)
{
struct netfs_io_request *wreq;
struct netfs_folio *finfo;
struct netfs_inode *ctx = netfs_inode(mapping->host);
unsigned long long i_size = i_size_read(&ctx->inode);
size_t len, max_len;
long count = wbc->nr_to_write;
int ret;
_enter(",%lx,%llx-%llx", folio->index, start, end);
wreq = netfs_alloc_request(mapping, NULL, start, folio_size(folio),
group == NETFS_FOLIO_COPY_TO_CACHE ?
NETFS_COPY_TO_CACHE : NETFS_WRITEBACK);
if (IS_ERR(wreq)) {
folio_unlock(folio);
return PTR_ERR(wreq);
}
if (!folio_clear_dirty_for_io(folio))
BUG();
folio_start_writeback(folio);
count -= folio_nr_pages(folio);
/* Find all consecutive lockable dirty pages that have contiguous
* written regions, stopping when we find a page that is not
* immediately lockable, is not dirty or is missing, or we reach the
* end of the range.
*/
if (group == NETFS_FOLIO_COPY_TO_CACHE)
trace_netfs_folio(folio, netfs_folio_trace_copy);
else
trace_netfs_folio(folio, netfs_folio_trace_store);
len = wreq->len;
finfo = netfs_folio_info(folio);
if (finfo) {
start += finfo->dirty_offset;
if (finfo->dirty_offset + finfo->dirty_len != len) {
len = finfo->dirty_len;
goto cant_expand;
}
len = finfo->dirty_len;
}
if (start < i_size) {
/* Trim the write to the EOF; the extra data is ignored. Also
* put an upper limit on the size of a single storedata op.
*/
max_len = 65536 * 4096;
max_len = min_t(unsigned long long, max_len, end - start + 1);
max_len = min_t(unsigned long long, max_len, i_size - start);
if (len < max_len)
netfs_extend_writeback(mapping, group, xas, &count, start,
max_len, &len, &wreq->upper_len);
}
cant_expand:
len = min_t(unsigned long long, len, i_size - start);
/* We now have a contiguous set of dirty pages, each with writeback
* set; the first page is still locked at this point, but all the rest
* have been unlocked.
*/
folio_unlock(folio);
wreq->start = start;
wreq->len = len;
if (start < i_size) {
_debug("write back %zx @%llx [%llx]", len, start, i_size);
/* Speculatively write to the cache. We have to fix this up
* later if the store fails.
*/
wreq->cleanup = netfs_cleanup_buffered_write;
iov_iter_xarray(&wreq->iter, ITER_SOURCE, &mapping->i_pages, start,
wreq->upper_len);
if (group != NETFS_FOLIO_COPY_TO_CACHE) {
__set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
ret = netfs_begin_write(wreq, true, netfs_write_trace_writeback);
} else {
ret = netfs_begin_write(wreq, true, netfs_write_trace_copy_to_cache);
}
if (ret == 0 || ret == -EIOCBQUEUED)
wbc->nr_to_write -= len / PAGE_SIZE;
} else {
_debug("write discard %zx @%llx [%llx]", len, start, i_size);
/* The dirty region was entirely beyond the EOF. */
netfs_pages_written_back(wreq);
ret = 0;
}
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
_leave(" = 1");
return 1;
}
/*
* Write a region of pages back to the server
*/
static ssize_t netfs_writepages_begin(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
struct xa_state *xas,
unsigned long long *_start,
unsigned long long end)
{
const struct netfs_folio *finfo;
struct folio *folio;
unsigned long long start = *_start;
ssize_t ret;
void *priv;
int skips = 0;
_enter("%llx,%llx,", start, end);
search_again:
/* Find the first dirty page in the group. */
rcu_read_lock();
for (;;) {
folio = xas_find_marked(xas, end / PAGE_SIZE, PAGECACHE_TAG_DIRTY);
if (xas_retry(xas, folio) || xa_is_value(folio))
continue;
if (!folio)
break;
if (!folio_try_get_rcu(folio)) {
xas_reset(xas);
continue;
}
if (unlikely(folio != xas_reload(xas))) {
folio_put(folio);
xas_reset(xas);
continue;
}
/* Skip any dirty folio that's not in the group of interest. */
priv = folio_get_private(folio);
if ((const struct netfs_group *)priv == NETFS_FOLIO_COPY_TO_CACHE) {
group = NETFS_FOLIO_COPY_TO_CACHE;
} else if ((const struct netfs_group *)priv != group) {
finfo = __netfs_folio_info(priv);
if (!finfo || finfo->netfs_group != group) {
folio_put(folio);
continue;
}
}
xas_pause(xas);
break;
}
rcu_read_unlock();
if (!folio)
return 0;
start = folio_pos(folio); /* May regress with THPs */
_debug("wback %lx", folio->index);
/* At this point we hold neither the i_pages lock nor the page lock:
* the page may be truncated or invalidated (changing page->mapping to
* NULL), or even swizzled back from swapper_space to tmpfs file
* mapping
*/
lock_again:
if (wbc->sync_mode != WB_SYNC_NONE) {
ret = folio_lock_killable(folio);
if (ret < 0)
return ret;
} else {
if (!folio_trylock(folio))
goto search_again;
}
if (folio->mapping != mapping ||
!folio_test_dirty(folio)) {
start += folio_size(folio);
folio_unlock(folio);
goto search_again;
}
if (folio_test_writeback(folio)) {
folio_unlock(folio);
if (wbc->sync_mode != WB_SYNC_NONE) {
folio_wait_writeback(folio);
goto lock_again;
}
start += folio_size(folio);
if (wbc->sync_mode == WB_SYNC_NONE) {
if (skips >= 5 || need_resched()) {
ret = 0;
goto out;
}
skips++;
}
goto search_again;
}
ret = netfs_write_back_from_locked_folio(mapping, wbc, group, xas,
folio, start, end);
out:
if (ret > 0)
*_start = start + ret;
_leave(" = %zd [%llx]", ret, *_start);
return ret;
}
/*
* Write a region of pages back to the server
*/
static int netfs_writepages_region(struct address_space *mapping,
struct writeback_control *wbc,
struct netfs_group *group,
unsigned long long *_start,
unsigned long long end)
{
ssize_t ret;
XA_STATE(xas, &mapping->i_pages, *_start / PAGE_SIZE);
do {
ret = netfs_writepages_begin(mapping, wbc, group, &xas,
_start, end);
if (ret > 0 && wbc->nr_to_write > 0)
cond_resched();
} while (ret > 0 && wbc->nr_to_write > 0);
return ret > 0 ? 0 : ret;
}
/*
* write some of the pending data back to the server
*/
int netfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct netfs_group *group = NULL;
loff_t start, end;
int ret;
_enter("");
/* 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->range_cyclic && mapping->writeback_index) {
start = mapping->writeback_index * PAGE_SIZE;
ret = netfs_writepages_region(mapping, wbc, group,
&start, LLONG_MAX);
if (ret < 0)
goto out;
if (wbc->nr_to_write <= 0) {
mapping->writeback_index = start / PAGE_SIZE;
goto out;
}
start = 0;
end = mapping->writeback_index * PAGE_SIZE;
mapping->writeback_index = 0;
ret = netfs_writepages_region(mapping, wbc, group, &start, end);
if (ret == 0)
mapping->writeback_index = start / PAGE_SIZE;
} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
start = 0;
ret = netfs_writepages_region(mapping, wbc, group,
&start, LLONG_MAX);
if (wbc->nr_to_write > 0 && ret == 0)
mapping->writeback_index = start / PAGE_SIZE;
} else {
start = wbc->range_start;
ret = netfs_writepages_region(mapping, wbc, group,
&start, wbc->range_end);
}
out:
_leave(" = %d", ret);
return ret;
}
EXPORT_SYMBOL(netfs_writepages);
#endif

477
fs/netfs/output.c
View file

@ -1,477 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Network filesystem high-level write support.
*
* Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include "internal.h"
/**
* netfs_create_write_request - Create a write operation.
* @wreq: The write request this is storing from.
* @dest: The destination type
* @start: Start of the region this write will modify
* @len: Length of the modification
* @worker: The worker function to handle the write(s)
*
* Allocate a write operation, set it up and add it to the list on a write
* request.
*/
struct netfs_io_subrequest *netfs_create_write_request(struct netfs_io_request *wreq,
enum netfs_io_source dest,
loff_t start, size_t len,
work_func_t worker)
{
struct netfs_io_subrequest *subreq;
subreq = netfs_alloc_subrequest(wreq);
if (subreq) {
INIT_WORK(&subreq->work, worker);
subreq->source = dest;
subreq->start = start;
subreq->len = len;
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write);
break;
default:
BUG();
}
subreq->io_iter = wreq->io_iter;
iov_iter_advance(&subreq->io_iter, subreq->start - wreq->start);
iov_iter_truncate(&subreq->io_iter, subreq->len);
trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index,
refcount_read(&subreq->ref),
netfs_sreq_trace_new);
atomic_inc(&wreq->nr_outstanding);
list_add_tail(&subreq->rreq_link, &wreq->subrequests);
trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
}
return subreq;
}
EXPORT_SYMBOL(netfs_create_write_request);
/*
* Process a completed write request once all the component operations have
* been completed.
*/
static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async)
{
struct netfs_io_subrequest *subreq;
struct netfs_inode *ctx = netfs_inode(wreq->inode);
size_t transferred = 0;
_enter("R=%x[]", wreq->debug_id);
trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
if (subreq->error || subreq->transferred == 0)
break;
transferred += subreq->transferred;
if (subreq->transferred < subreq->len)
break;
}
wreq->transferred = transferred;
list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
if (!subreq->error)
continue;
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
/* Depending on the type of failure, this may prevent
* writeback completion unless we're in disconnected
* mode.
*/
if (!wreq->error)
wreq->error = subreq->error;
break;
case NETFS_WRITE_TO_CACHE:
/* Failure doesn't prevent writeback completion unless
* we're in disconnected mode.
*/
if (subreq->error != -ENOBUFS)
ctx->ops->invalidate_cache(wreq);
break;
default:
WARN_ON_ONCE(1);
if (!wreq->error)
wreq->error = -EIO;
return;
}
}
wreq->cleanup(wreq);
if (wreq->origin == NETFS_DIO_WRITE &&
wreq->mapping->nrpages) {
pgoff_t first = wreq->start >> PAGE_SHIFT;
pgoff_t last = (wreq->start + wreq->transferred - 1) >> PAGE_SHIFT;
invalidate_inode_pages2_range(wreq->mapping, first, last);
}
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_end(wreq->inode);
_debug("finished");
trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
if (wreq->iocb) {
wreq->iocb->ki_pos += transferred;
if (wreq->iocb->ki_complete)
wreq->iocb->ki_complete(
wreq->iocb, wreq->error ? wreq->error : transferred);
}
netfs_clear_subrequests(wreq, was_async);
netfs_put_request(wreq, was_async, netfs_rreq_trace_put_complete);
}
/*
* Deal with the completion of writing the data to the cache.
*/
void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
bool was_async)
{
struct netfs_io_subrequest *subreq = _op;
struct netfs_io_request *wreq = subreq->rreq;
unsigned int u;
_enter("%x[%x] %zd", wreq->debug_id, subreq->debug_index, transferred_or_error);
switch (subreq->source) {
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_done);
break;
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_done);
break;
case NETFS_INVALID_WRITE:
break;
default:
BUG();
}
if (IS_ERR_VALUE(transferred_or_error)) {
subreq->error = transferred_or_error;
trace_netfs_failure(wreq, subreq, transferred_or_error,
netfs_fail_write);
goto failed;
}
if (WARN(transferred_or_error > subreq->len - subreq->transferred,
"Subreq excess write: R%x[%x] %zd > %zu - %zu",
wreq->debug_id, subreq->debug_index,
transferred_or_error, subreq->len, subreq->transferred))
transferred_or_error = subreq->len - subreq->transferred;
subreq->error = 0;
subreq->transferred += transferred_or_error;
if (iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
pr_warn("R=%08x[%u] ITER POST-MISMATCH %zx != %zx-%zx %x\n",
wreq->debug_id, subreq->debug_index,
iov_iter_count(&subreq->io_iter), subreq->len,
subreq->transferred, subreq->io_iter.iter_type);
if (subreq->transferred < subreq->len)
goto incomplete;
__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
out:
trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
/* If we decrement nr_outstanding to 0, the ref belongs to us. */
u = atomic_dec_return(&wreq->nr_outstanding);
if (u == 0)
netfs_write_terminated(wreq, was_async);
else if (u == 1)
wake_up_var(&wreq->nr_outstanding);
netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
return;
incomplete:
if (transferred_or_error == 0) {
if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) {
subreq->error = -ENODATA;
goto failed;
}
} else {
__clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
}
__set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
goto out;
failed:
switch (subreq->source) {
case NETFS_WRITE_TO_CACHE:
netfs_stat(&netfs_n_wh_write_failed);
set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
break;
case NETFS_UPLOAD_TO_SERVER:
netfs_stat(&netfs_n_wh_upload_failed);
set_bit(NETFS_RREQ_FAILED, &wreq->flags);
wreq->error = subreq->error;
break;
default:
break;
}
goto out;
}
EXPORT_SYMBOL(netfs_write_subrequest_terminated);
static void netfs_write_to_cache_op(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *wreq = subreq->rreq;
struct netfs_cache_resources *cres = &wreq->cache_resources;
trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
cres->ops->write(cres, subreq->start, &subreq->io_iter,
netfs_write_subrequest_terminated, subreq);
}
static void netfs_write_to_cache_op_worker(struct work_struct *work)
{
struct netfs_io_subrequest *subreq =
container_of(work, struct netfs_io_subrequest, work);
netfs_write_to_cache_op(subreq);
}
/**
* netfs_queue_write_request - Queue a write request for attention
* @subreq: The write request to be queued
*
* Queue the specified write request for processing by a worker thread. We
* pass the caller's ref on the request to the worker thread.
*/
void netfs_queue_write_request(struct netfs_io_subrequest *subreq)
{
if (!queue_work(system_unbound_wq, &subreq->work))
netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_wip);
}
EXPORT_SYMBOL(netfs_queue_write_request);
/*
* Set up a op for writing to the cache.
*/
static void netfs_set_up_write_to_cache(struct netfs_io_request *wreq)
{
struct netfs_cache_resources *cres = &wreq->cache_resources;
struct netfs_io_subrequest *subreq;
struct netfs_inode *ctx = netfs_inode(wreq->inode);
struct fscache_cookie *cookie = netfs_i_cookie(ctx);
loff_t start = wreq->start;
size_t len = wreq->len;
int ret;
if (!fscache_cookie_enabled(cookie)) {
clear_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags);
return;
}
_debug("write to cache");
ret = fscache_begin_write_operation(cres, cookie);
if (ret < 0)
return;
ret = cres->ops->prepare_write(cres, &start, &len, wreq->upper_len,
i_size_read(wreq->inode), true);
if (ret < 0)
return;
subreq = netfs_create_write_request(wreq, NETFS_WRITE_TO_CACHE, start, len,
netfs_write_to_cache_op_worker);
if (!subreq)
return;
netfs_write_to_cache_op(subreq);
}
/*
* Begin the process of writing out a chunk of data.
*
* We are given a write request that holds a series of dirty regions and
* (partially) covers a sequence of folios, all of which are present. The
* pages must have been marked as writeback as appropriate.
*
* We need to perform the following steps:
*
* (1) If encrypting, create an output buffer and encrypt each block of the
* data into it, otherwise the output buffer will point to the original
* folios.
*
* (2) If the data is to be cached, set up a write op for the entire output
* buffer to the cache, if the cache wants to accept it.
*
* (3) If the data is to be uploaded (ie. not merely cached):
*
* (a) If the data is to be compressed, create a compression buffer and
* compress the data into it.
*
* (b) For each destination we want to upload to, set up write ops to write
* to that destination. We may need multiple writes if the data is not
* contiguous or the span exceeds wsize for a server.
*/
int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
enum netfs_write_trace what)
{
struct netfs_inode *ctx = netfs_inode(wreq->inode);
_enter("R=%x %llx-%llx f=%lx",
wreq->debug_id, wreq->start, wreq->start + wreq->len - 1,
wreq->flags);
trace_netfs_write(wreq, what);
if (wreq->len == 0 || wreq->iter.count == 0) {
pr_err("Zero-sized write [R=%x]\n", wreq->debug_id);
return -EIO;
}
if (wreq->origin == NETFS_DIO_WRITE)
inode_dio_begin(wreq->inode);
wreq->io_iter = wreq->iter;
/* ->outstanding > 0 carries a ref */
netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
atomic_set(&wreq->nr_outstanding, 1);
/* Start the encryption/compression going. We can do that in the
* background whilst we generate a list of write ops that we want to
* perform.
*/
// TODO: Encrypt or compress the region as appropriate
/* We need to write all of the region to the cache */
if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags))
netfs_set_up_write_to_cache(wreq);
/* However, we don't necessarily write all of the region to the server.
* Caching of reads is being managed this way also.
*/
if (test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
ctx->ops->create_write_requests(wreq, wreq->start, wreq->len);
if (atomic_dec_and_test(&wreq->nr_outstanding))
netfs_write_terminated(wreq, false);
if (!may_wait)
return -EIOCBQUEUED;
wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
return wreq->error;
}
/*
* Begin a write operation for writing through the pagecache.
*/
struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len)
{
struct netfs_io_request *wreq;
struct file *file = iocb->ki_filp;
wreq = netfs_alloc_request(file->f_mapping, file, iocb->ki_pos, len,
NETFS_WRITETHROUGH);
if (IS_ERR(wreq))
return wreq;
trace_netfs_write(wreq, netfs_write_trace_writethrough);
__set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
iov_iter_xarray(&wreq->iter, ITER_SOURCE, &wreq->mapping->i_pages, wreq->start, 0);
wreq->io_iter = wreq->iter;
/* ->outstanding > 0 carries a ref */
netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
atomic_set(&wreq->nr_outstanding, 1);
return wreq;
}
static void netfs_submit_writethrough(struct netfs_io_request *wreq, bool final)
{
struct netfs_inode *ictx = netfs_inode(wreq->inode);
unsigned long long start;
size_t len;
if (!test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
return;
start = wreq->start + wreq->submitted;
len = wreq->iter.count - wreq->submitted;
if (!final) {
len /= wreq->wsize; /* Round to number of maximum packets */
len *= wreq->wsize;
}
ictx->ops->create_write_requests(wreq, start, len);
wreq->submitted += len;
}
/*
* Advance the state of the write operation used when writing through the
* pagecache. Data has been copied into the pagecache that we need to append
* to the request. If we've added more than wsize then we need to create a new
* subrequest.
*/
int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end)
{
_enter("ic=%zu sb=%llu ws=%u cp=%zu tp=%u",
wreq->iter.count, wreq->submitted, wreq->wsize, copied, to_page_end);
wreq->iter.count += copied;
wreq->io_iter.count += copied;
if (to_page_end && wreq->io_iter.count - wreq->submitted >= wreq->wsize)
netfs_submit_writethrough(wreq, false);
return wreq->error;
}
/*
* End a write operation used when writing through the pagecache.
*/
int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb)
{
int ret = -EIOCBQUEUED;
_enter("ic=%zu sb=%llu ws=%u",
wreq->iter.count, wreq->submitted, wreq->wsize);
if (wreq->submitted < wreq->io_iter.count)
netfs_submit_writethrough(wreq, true);
if (atomic_dec_and_test(&wreq->nr_outstanding))
netfs_write_terminated(wreq, false);
if (is_sync_kiocb(iocb)) {
wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
TASK_UNINTERRUPTIBLE);
ret = wreq->error;
}
netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
return ret;
}