v4.19.13 snapshot.
diff --git a/fs/afs/write.c b/fs/afs/write.c
new file mode 100644
index 0000000..19c04ca
--- /dev/null
+++ b/fs/afs/write.c
@@ -0,0 +1,866 @@
+/* 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)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/backing-dev.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include "internal.h"
+
+/*
+ * mark a page as having been made dirty and thus needing writeback
+ */
+int afs_set_page_dirty(struct page *page)
+{
+ _enter("");
+ return __set_page_dirty_nobuffers(page);
+}
+
+/*
+ * partly or wholly fill a page that's under preparation for writing
+ */
+static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
+ loff_t pos, unsigned int len, struct page *page)
+{
+ struct afs_read *req;
+ int ret;
+
+ _enter(",,%llu", (unsigned long long)pos);
+
+ req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
+ GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ refcount_set(&req->usage, 1);
+ req->pos = pos;
+ req->len = len;
+ req->nr_pages = 1;
+ req->pages = req->array;
+ req->pages[0] = page;
+ get_page(page);
+
+ ret = afs_fetch_data(vnode, key, req);
+ afs_put_read(req);
+ if (ret < 0) {
+ if (ret == -ENOENT) {
+ _debug("got NOENT from server"
+ " - marking file deleted and stale");
+ set_bit(AFS_VNODE_DELETED, &vnode->flags);
+ ret = -ESTALE;
+ }
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * prepare to perform part of a write to a page
+ */
+int afs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+ struct page *page;
+ struct key *key = afs_file_key(file);
+ unsigned long priv;
+ unsigned f, from = pos & (PAGE_SIZE - 1);
+ unsigned t, to = from + len;
+ pgoff_t index = pos >> PAGE_SHIFT;
+ int ret;
+
+ _enter("{%x:%u},{%lx},%u,%u",
+ vnode->fid.vid, vnode->fid.vnode, index, from, to);
+
+ /* We want to store information about how much of a page is altered in
+ * page->private.
+ */
+ BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
+
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+
+ if (!PageUptodate(page) && len != PAGE_SIZE) {
+ ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
+ if (ret < 0) {
+ unlock_page(page);
+ put_page(page);
+ _leave(" = %d [prep]", ret);
+ return ret;
+ }
+ SetPageUptodate(page);
+ }
+
+ /* page won't leak in error case: it eventually gets cleaned off LRU */
+ *pagep = page;
+
+try_again:
+ /* See if this page is already partially written in a way that we can
+ * merge the new write with.
+ */
+ t = f = 0;
+ if (PagePrivate(page)) {
+ priv = page_private(page);
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ ASSERTCMP(f, <=, t);
+ }
+
+ if (f != t) {
+ if (PageWriteback(page)) {
+ trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
+ page->index, priv);
+ goto flush_conflicting_write;
+ }
+ /* If the file is being filled locally, allow inter-write
+ * spaces to be merged into writes. If it's not, only write
+ * back what the user gives us.
+ */
+ if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
+ (to < f || from > t))
+ goto flush_conflicting_write;
+ if (from < f)
+ f = from;
+ if (to > t)
+ t = to;
+ } else {
+ f = from;
+ t = to;
+ }
+
+ priv = (unsigned long)t << AFS_PRIV_SHIFT;
+ priv |= f;
+ trace_afs_page_dirty(vnode, tracepoint_string("begin"),
+ page->index, priv);
+ SetPagePrivate(page);
+ set_page_private(page, priv);
+ _leave(" = 0");
+ return 0;
+
+ /* The previous write and this write aren't adjacent or overlapping, so
+ * flush the page out.
+ */
+flush_conflicting_write:
+ _debug("flush conflict");
+ ret = write_one_page(page);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ ret = lock_page_killable(page);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return ret;
+ }
+ goto try_again;
+}
+
+/*
+ * finalise part of a write to a page
+ */
+int afs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+ struct key *key = afs_file_key(file);
+ loff_t i_size, maybe_i_size;
+ int ret;
+
+ _enter("{%x:%u},{%lx}",
+ vnode->fid.vid, vnode->fid.vnode, page->index);
+
+ maybe_i_size = pos + copied;
+
+ i_size = i_size_read(&vnode->vfs_inode);
+ if (maybe_i_size > i_size) {
+ spin_lock(&vnode->wb_lock);
+ i_size = i_size_read(&vnode->vfs_inode);
+ if (maybe_i_size > i_size)
+ i_size_write(&vnode->vfs_inode, maybe_i_size);
+ spin_unlock(&vnode->wb_lock);
+ }
+
+ if (!PageUptodate(page)) {
+ if (copied < len) {
+ /* Try and load any missing data from the server. The
+ * unmarshalling routine will take care of clearing any
+ * bits that are beyond the EOF.
+ */
+ ret = afs_fill_page(vnode, key, pos + copied,
+ len - copied, page);
+ if (ret < 0)
+ goto out;
+ }
+ SetPageUptodate(page);
+ }
+
+ set_page_dirty(page);
+ if (PageDirty(page))
+ _debug("dirtied");
+ ret = copied;
+
+out:
+ unlock_page(page);
+ put_page(page);
+ return ret;
+}
+
+/*
+ * kill all the pages in the given range
+ */
+static void afs_kill_pages(struct address_space *mapping,
+ pgoff_t first, pgoff_t last)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct pagevec pv;
+ unsigned count, loop;
+
+ _enter("{%x:%u},%lx-%lx",
+ vnode->fid.vid, vnode->fid.vnode, first, last);
+
+ pagevec_init(&pv);
+
+ do {
+ _debug("kill %lx-%lx", first, last);
+
+ count = last - first + 1;
+ if (count > PAGEVEC_SIZE)
+ count = PAGEVEC_SIZE;
+ pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
+ ASSERTCMP(pv.nr, ==, count);
+
+ for (loop = 0; loop < count; loop++) {
+ struct page *page = pv.pages[loop];
+ ClearPageUptodate(page);
+ SetPageError(page);
+ end_page_writeback(page);
+ if (page->index >= first)
+ first = page->index + 1;
+ lock_page(page);
+ generic_error_remove_page(mapping, page);
+ }
+
+ __pagevec_release(&pv);
+ } while (first <= last);
+
+ _leave("");
+}
+
+/*
+ * Redirty all the pages in a given range.
+ */
+static void afs_redirty_pages(struct writeback_control *wbc,
+ struct address_space *mapping,
+ pgoff_t first, pgoff_t last)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct pagevec pv;
+ unsigned count, loop;
+
+ _enter("{%x:%u},%lx-%lx",
+ vnode->fid.vid, vnode->fid.vnode, first, last);
+
+ pagevec_init(&pv);
+
+ do {
+ _debug("redirty %lx-%lx", first, last);
+
+ count = last - first + 1;
+ if (count > PAGEVEC_SIZE)
+ count = PAGEVEC_SIZE;
+ pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
+ ASSERTCMP(pv.nr, ==, count);
+
+ for (loop = 0; loop < count; loop++) {
+ struct page *page = pv.pages[loop];
+
+ redirty_page_for_writepage(wbc, page);
+ end_page_writeback(page);
+ if (page->index >= first)
+ first = page->index + 1;
+ }
+
+ __pagevec_release(&pv);
+ } while (first <= last);
+
+ _leave("");
+}
+
+/*
+ * write to a file
+ */
+static int afs_store_data(struct address_space *mapping,
+ pgoff_t first, pgoff_t last,
+ unsigned offset, unsigned to)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct afs_fs_cursor fc;
+ struct afs_wb_key *wbk = NULL;
+ struct list_head *p;
+ int ret = -ENOKEY, ret2;
+
+ _enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
+ vnode->volume->name,
+ vnode->fid.vid,
+ vnode->fid.vnode,
+ vnode->fid.unique,
+ first, last, offset, to);
+
+ spin_lock(&vnode->wb_lock);
+ p = vnode->wb_keys.next;
+
+ /* Iterate through the list looking for a valid key to use. */
+try_next_key:
+ while (p != &vnode->wb_keys) {
+ wbk = list_entry(p, struct afs_wb_key, vnode_link);
+ _debug("wbk %u", key_serial(wbk->key));
+ ret2 = key_validate(wbk->key);
+ if (ret2 == 0)
+ goto found_key;
+ if (ret == -ENOKEY)
+ ret = ret2;
+ p = p->next;
+ }
+
+ spin_unlock(&vnode->wb_lock);
+ afs_put_wb_key(wbk);
+ _leave(" = %d [no keys]", ret);
+ return ret;
+
+found_key:
+ refcount_inc(&wbk->usage);
+ spin_unlock(&vnode->wb_lock);
+
+ _debug("USE WB KEY %u", key_serial(wbk->key));
+
+ ret = -ERESTARTSYS;
+ if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = afs_calc_vnode_cb_break(vnode);
+ afs_fs_store_data(&fc, mapping, first, last, offset, to);
+ }
+
+ afs_check_for_remote_deletion(&fc, fc.vnode);
+ afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ }
+
+ switch (ret) {
+ case 0:
+ afs_stat_v(vnode, n_stores);
+ atomic_long_add((last * PAGE_SIZE + to) -
+ (first * PAGE_SIZE + offset),
+ &afs_v2net(vnode)->n_store_bytes);
+ break;
+ case -EACCES:
+ case -EPERM:
+ case -ENOKEY:
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EKEYREVOKED:
+ _debug("next");
+ spin_lock(&vnode->wb_lock);
+ p = wbk->vnode_link.next;
+ afs_put_wb_key(wbk);
+ goto try_next_key;
+ }
+
+ afs_put_wb_key(wbk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Synchronously write back the locked page and any subsequent non-locked dirty
+ * pages.
+ */
+static int afs_write_back_from_locked_page(struct address_space *mapping,
+ struct writeback_control *wbc,
+ struct page *primary_page,
+ pgoff_t final_page)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct page *pages[8], *page;
+ unsigned long count, priv;
+ unsigned n, offset, to, f, t;
+ pgoff_t start, first, last;
+ int loop, ret;
+
+ _enter(",%lx", primary_page->index);
+
+ count = 1;
+ if (test_set_page_writeback(primary_page))
+ BUG();
+
+ /* 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.
+ */
+ start = primary_page->index;
+ priv = page_private(primary_page);
+ offset = priv & AFS_PRIV_MAX;
+ to = priv >> AFS_PRIV_SHIFT;
+ trace_afs_page_dirty(vnode, tracepoint_string("store"),
+ primary_page->index, priv);
+
+ WARN_ON(offset == to);
+ if (offset == to)
+ trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
+ primary_page->index, priv);
+
+ if (start >= final_page ||
+ (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
+ goto no_more;
+
+ start++;
+ do {
+ _debug("more %lx [%lx]", start, count);
+ n = final_page - start + 1;
+ if (n > ARRAY_SIZE(pages))
+ n = ARRAY_SIZE(pages);
+ n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
+ _debug("fgpc %u", n);
+ if (n == 0)
+ goto no_more;
+ if (pages[0]->index != start) {
+ do {
+ put_page(pages[--n]);
+ } while (n > 0);
+ goto no_more;
+ }
+
+ for (loop = 0; loop < n; loop++) {
+ page = pages[loop];
+ if (to != PAGE_SIZE &&
+ !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
+ break;
+ if (page->index > final_page)
+ break;
+ if (!trylock_page(page))
+ break;
+ if (!PageDirty(page) || PageWriteback(page)) {
+ unlock_page(page);
+ break;
+ }
+
+ priv = page_private(page);
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ if (f != 0 &&
+ !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
+ unlock_page(page);
+ break;
+ }
+ to = t;
+
+ trace_afs_page_dirty(vnode, tracepoint_string("store+"),
+ page->index, priv);
+
+ if (!clear_page_dirty_for_io(page))
+ BUG();
+ if (test_set_page_writeback(page))
+ BUG();
+ unlock_page(page);
+ put_page(page);
+ }
+ count += loop;
+ if (loop < n) {
+ for (; loop < n; loop++)
+ put_page(pages[loop]);
+ goto no_more;
+ }
+
+ start += loop;
+ } while (start <= final_page && count < 65536);
+
+no_more:
+ /* 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.
+ */
+ unlock_page(primary_page);
+
+ first = primary_page->index;
+ last = first + count - 1;
+
+ _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
+
+ ret = afs_store_data(mapping, first, last, offset, to);
+ switch (ret) {
+ case 0:
+ ret = count;
+ break;
+
+ default:
+ pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
+ /* Fall through */
+ case -EACCES:
+ case -EPERM:
+ case -ENOKEY:
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EKEYREVOKED:
+ afs_redirty_pages(wbc, mapping, first, last);
+ mapping_set_error(mapping, ret);
+ break;
+
+ case -EDQUOT:
+ case -ENOSPC:
+ afs_redirty_pages(wbc, mapping, first, last);
+ mapping_set_error(mapping, -ENOSPC);
+ break;
+
+ case -EROFS:
+ case -EIO:
+ case -EREMOTEIO:
+ case -EFBIG:
+ case -ENOENT:
+ case -ENOMEDIUM:
+ case -ENXIO:
+ afs_kill_pages(mapping, first, last);
+ mapping_set_error(mapping, ret);
+ break;
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * write a page back to the server
+ * - the caller locked the page for us
+ */
+int afs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ int ret;
+
+ _enter("{%lx},", page->index);
+
+ ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
+ wbc->range_end >> PAGE_SHIFT);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return 0;
+ }
+
+ wbc->nr_to_write -= ret;
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * write a region of pages back to the server
+ */
+static int afs_writepages_region(struct address_space *mapping,
+ struct writeback_control *wbc,
+ pgoff_t index, pgoff_t end, pgoff_t *_next)
+{
+ struct page *page;
+ int ret, n;
+
+ _enter(",,%lx,%lx,", index, end);
+
+ do {
+ n = find_get_pages_range_tag(mapping, &index, end,
+ PAGECACHE_TAG_DIRTY, 1, &page);
+ if (!n)
+ break;
+
+ _debug("wback %lx", page->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
+ */
+ ret = lock_page_killable(page);
+ if (ret < 0) {
+ put_page(page);
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ if (page->mapping != mapping || !PageDirty(page)) {
+ unlock_page(page);
+ put_page(page);
+ continue;
+ }
+
+ if (PageWriteback(page)) {
+ unlock_page(page);
+ if (wbc->sync_mode != WB_SYNC_NONE)
+ wait_on_page_writeback(page);
+ put_page(page);
+ continue;
+ }
+
+ if (!clear_page_dirty_for_io(page))
+ BUG();
+ ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
+ put_page(page);
+ if (ret < 0) {
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ wbc->nr_to_write -= ret;
+
+ cond_resched();
+ } while (index < end && wbc->nr_to_write > 0);
+
+ *_next = index;
+ _leave(" = 0 [%lx]", *_next);
+ return 0;
+}
+
+/*
+ * write some of the pending data back to the server
+ */
+int afs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ pgoff_t start, end, next;
+ int ret;
+
+ _enter("");
+
+ if (wbc->range_cyclic) {
+ start = mapping->writeback_index;
+ end = -1;
+ ret = afs_writepages_region(mapping, wbc, start, end, &next);
+ if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
+ ret = afs_writepages_region(mapping, wbc, 0, start,
+ &next);
+ mapping->writeback_index = next;
+ } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
+ end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
+ ret = afs_writepages_region(mapping, wbc, 0, end, &next);
+ if (wbc->nr_to_write > 0)
+ mapping->writeback_index = next;
+ } else {
+ start = wbc->range_start >> PAGE_SHIFT;
+ end = wbc->range_end >> PAGE_SHIFT;
+ ret = afs_writepages_region(mapping, wbc, start, end, &next);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * completion of write to server
+ */
+void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
+{
+ struct pagevec pv;
+ unsigned long priv;
+ unsigned count, loop;
+ pgoff_t first = call->first, last = call->last;
+
+ _enter("{%x:%u},{%lx-%lx}",
+ vnode->fid.vid, vnode->fid.vnode, first, last);
+
+ pagevec_init(&pv);
+
+ do {
+ _debug("done %lx-%lx", first, last);
+
+ count = last - first + 1;
+ if (count > PAGEVEC_SIZE)
+ count = PAGEVEC_SIZE;
+ pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
+ first, count, pv.pages);
+ ASSERTCMP(pv.nr, ==, count);
+
+ for (loop = 0; loop < count; loop++) {
+ priv = page_private(pv.pages[loop]);
+ trace_afs_page_dirty(vnode, tracepoint_string("clear"),
+ pv.pages[loop]->index, priv);
+ set_page_private(pv.pages[loop], 0);
+ end_page_writeback(pv.pages[loop]);
+ }
+ first += count;
+ __pagevec_release(&pv);
+ } while (first <= last);
+
+ afs_prune_wb_keys(vnode);
+ _leave("");
+}
+
+/*
+ * write to an AFS file
+ */
+ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
+ ssize_t result;
+ size_t count = iov_iter_count(from);
+
+ _enter("{%x.%u},{%zu},",
+ vnode->fid.vid, vnode->fid.vnode, count);
+
+ if (IS_SWAPFILE(&vnode->vfs_inode)) {
+ printk(KERN_INFO
+ "AFS: Attempt to write to active swap file!\n");
+ return -EBUSY;
+ }
+
+ if (!count)
+ return 0;
+
+ result = generic_file_write_iter(iocb, from);
+
+ _leave(" = %zd", result);
+ return result;
+}
+
+/*
+ * 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 inode *inode = file_inode(file);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+
+ _enter("{%x:%u},{n=%pD},%d",
+ vnode->fid.vid, vnode->fid.vnode, file,
+ datasync);
+
+ 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;
+ struct inode *inode = file_inode(file);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ unsigned long priv;
+
+ _enter("{{%x:%u}},{%lx}",
+ vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
+
+ sb_start_pagefault(inode->i_sb);
+
+ /* Wait for the page to be written to the cache before we allow it to
+ * be modified. We then assume the entire page will need writing back.
+ */
+#ifdef CONFIG_AFS_FSCACHE
+ fscache_wait_on_page_write(vnode->cache, vmf->page);
+#endif
+
+ if (PageWriteback(vmf->page) &&
+ wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
+ return VM_FAULT_RETRY;
+
+ if (lock_page_killable(vmf->page) < 0)
+ return VM_FAULT_RETRY;
+
+ /* We mustn't change page->private until writeback is complete as that
+ * details the portion of the page we need to write back and we might
+ * need to redirty the page if there's a problem.
+ */
+ wait_on_page_writeback(vmf->page);
+
+ priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
+ priv |= 0; /* From */
+ trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
+ vmf->page->index, priv);
+ SetPagePrivate(vmf->page);
+ set_page_private(vmf->page, priv);
+
+ sb_end_pagefault(inode->i_sb);
+ return VM_FAULT_LOCKED;
+}
+
+/*
+ * 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->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
+ !mapping_tagged(&vnode->vfs_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);
+ }
+}
+
+/*
+ * Clean up a page during invalidation.
+ */
+int afs_launder_page(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ unsigned long priv;
+ unsigned int f, t;
+ int ret = 0;
+
+ _enter("{%lx}", page->index);
+
+ priv = page_private(page);
+ if (clear_page_dirty_for_io(page)) {
+ f = 0;
+ t = PAGE_SIZE;
+ if (PagePrivate(page)) {
+ f = priv & AFS_PRIV_MAX;
+ t = priv >> AFS_PRIV_SHIFT;
+ }
+
+ trace_afs_page_dirty(vnode, tracepoint_string("launder"),
+ page->index, priv);
+ ret = afs_store_data(mapping, page->index, page->index, t, f);
+ }
+
+ trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
+ page->index, priv);
+ set_page_private(page, 0);
+ ClearPagePrivate(page);
+
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page)) {
+ fscache_wait_on_page_write(vnode->cache, page);
+ fscache_uncache_page(vnode->cache, page);
+ }
+#endif
+ return ret;
+}