xref: /openbmc/linux/fs/afs/write.c (revision f51375cd)
131143d5dSDavid Howells /* handling of writes to regular files and writing back to the server
231143d5dSDavid Howells  *
331143d5dSDavid Howells  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
431143d5dSDavid Howells  * Written by David Howells (dhowells@redhat.com)
531143d5dSDavid Howells  *
631143d5dSDavid Howells  * This program is free software; you can redistribute it and/or
731143d5dSDavid Howells  * modify it under the terms of the GNU General Public License
831143d5dSDavid Howells  * as published by the Free Software Foundation; either version
931143d5dSDavid Howells  * 2 of the License, or (at your option) any later version.
1031143d5dSDavid Howells  */
114343d008SDavid Howells 
124af3c9ccSAlexey Dobriyan #include <linux/backing-dev.h>
1331143d5dSDavid Howells #include <linux/slab.h>
1431143d5dSDavid Howells #include <linux/fs.h>
1531143d5dSDavid Howells #include <linux/pagemap.h>
1631143d5dSDavid Howells #include <linux/writeback.h>
1731143d5dSDavid Howells #include <linux/pagevec.h>
1831143d5dSDavid Howells #include "internal.h"
1931143d5dSDavid Howells 
2031143d5dSDavid Howells /*
2131143d5dSDavid Howells  * mark a page as having been made dirty and thus needing writeback
2231143d5dSDavid Howells  */
2331143d5dSDavid Howells int afs_set_page_dirty(struct page *page)
2431143d5dSDavid Howells {
2531143d5dSDavid Howells 	_enter("");
2631143d5dSDavid Howells 	return __set_page_dirty_nobuffers(page);
2731143d5dSDavid Howells }
2831143d5dSDavid Howells 
2931143d5dSDavid Howells /*
3031143d5dSDavid Howells  * partly or wholly fill a page that's under preparation for writing
3131143d5dSDavid Howells  */
3231143d5dSDavid Howells static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
33e8e581a8SDavid Howells 			 loff_t pos, unsigned int len, struct page *page)
3431143d5dSDavid Howells {
35196ee9cdSDavid Howells 	struct afs_read *req;
3631143d5dSDavid Howells 	int ret;
3731143d5dSDavid Howells 
385e7f2337SAnton Blanchard 	_enter(",,%llu", (unsigned long long)pos);
3931143d5dSDavid Howells 
40196ee9cdSDavid Howells 	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
41196ee9cdSDavid Howells 		      GFP_KERNEL);
42196ee9cdSDavid Howells 	if (!req)
43196ee9cdSDavid Howells 		return -ENOMEM;
44196ee9cdSDavid Howells 
45f3ddee8dSDavid Howells 	refcount_set(&req->usage, 1);
46196ee9cdSDavid Howells 	req->pos = pos;
47e8e581a8SDavid Howells 	req->len = len;
48196ee9cdSDavid Howells 	req->nr_pages = 1;
49f3ddee8dSDavid Howells 	req->pages = req->array;
50196ee9cdSDavid Howells 	req->pages[0] = page;
515611ef28SDavid Howells 	get_page(page);
52196ee9cdSDavid Howells 
53d2ddc776SDavid Howells 	ret = afs_fetch_data(vnode, key, req);
54196ee9cdSDavid Howells 	afs_put_read(req);
5531143d5dSDavid Howells 	if (ret < 0) {
5631143d5dSDavid Howells 		if (ret == -ENOENT) {
5731143d5dSDavid Howells 			_debug("got NOENT from server"
5831143d5dSDavid Howells 			       " - marking file deleted and stale");
5931143d5dSDavid Howells 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
6031143d5dSDavid Howells 			ret = -ESTALE;
6131143d5dSDavid Howells 		}
6231143d5dSDavid Howells 	}
6331143d5dSDavid Howells 
6431143d5dSDavid Howells 	_leave(" = %d", ret);
6531143d5dSDavid Howells 	return ret;
6631143d5dSDavid Howells }
6731143d5dSDavid Howells 
6831143d5dSDavid Howells /*
6931143d5dSDavid Howells  * prepare to perform part of a write to a page
7031143d5dSDavid Howells  */
7115b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping,
7215b4650eSNick Piggin 		    loff_t pos, unsigned len, unsigned flags,
7315b4650eSNick Piggin 		    struct page **pagep, void **fsdata)
7431143d5dSDavid Howells {
75496ad9aaSAl Viro 	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
7615b4650eSNick Piggin 	struct page *page;
77215804a9SDavid Howells 	struct key *key = afs_file_key(file);
784343d008SDavid Howells 	unsigned long priv;
794343d008SDavid Howells 	unsigned f, from = pos & (PAGE_SIZE - 1);
804343d008SDavid Howells 	unsigned t, to = from + len;
8109cbfeafSKirill A. Shutemov 	pgoff_t index = pos >> PAGE_SHIFT;
8231143d5dSDavid Howells 	int ret;
8331143d5dSDavid Howells 
8431143d5dSDavid Howells 	_enter("{%x:%u},{%lx},%u,%u",
8515b4650eSNick Piggin 	       vnode->fid.vid, vnode->fid.vnode, index, from, to);
8631143d5dSDavid Howells 
874343d008SDavid Howells 	/* We want to store information about how much of a page is altered in
884343d008SDavid Howells 	 * page->private.
894343d008SDavid Howells 	 */
904343d008SDavid Howells 	BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8);
9131143d5dSDavid Howells 
9254566b2cSNick Piggin 	page = grab_cache_page_write_begin(mapping, index, flags);
934343d008SDavid Howells 	if (!page)
9415b4650eSNick Piggin 		return -ENOMEM;
9515b4650eSNick Piggin 
9609cbfeafSKirill A. Shutemov 	if (!PageUptodate(page) && len != PAGE_SIZE) {
97e8e581a8SDavid Howells 		ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
9831143d5dSDavid Howells 		if (ret < 0) {
996d06b0d2SDavid Howells 			unlock_page(page);
1006d06b0d2SDavid Howells 			put_page(page);
10131143d5dSDavid Howells 			_leave(" = %d [prep]", ret);
10231143d5dSDavid Howells 			return ret;
10331143d5dSDavid Howells 		}
10415b4650eSNick Piggin 		SetPageUptodate(page);
10531143d5dSDavid Howells 	}
10631143d5dSDavid Howells 
1076d06b0d2SDavid Howells 	/* page won't leak in error case: it eventually gets cleaned off LRU */
1086d06b0d2SDavid Howells 	*pagep = page;
1096d06b0d2SDavid Howells 
11031143d5dSDavid Howells try_again:
1114343d008SDavid Howells 	/* See if this page is already partially written in a way that we can
1124343d008SDavid Howells 	 * merge the new write with.
1134343d008SDavid Howells 	 */
1144343d008SDavid Howells 	t = f = 0;
1154343d008SDavid Howells 	if (PagePrivate(page)) {
1164343d008SDavid Howells 		priv = page_private(page);
1174343d008SDavid Howells 		f = priv & AFS_PRIV_MAX;
1184343d008SDavid Howells 		t = priv >> AFS_PRIV_SHIFT;
1194343d008SDavid Howells 		ASSERTCMP(f, <=, t);
12031143d5dSDavid Howells 	}
12131143d5dSDavid Howells 
1224343d008SDavid Howells 	if (f != t) {
1235a039c32SDavid Howells 		if (PageWriteback(page)) {
1245a039c32SDavid Howells 			trace_afs_page_dirty(vnode, tracepoint_string("alrdy"),
1255a039c32SDavid Howells 					     page->index, priv);
1265a039c32SDavid Howells 			goto flush_conflicting_write;
1275a039c32SDavid Howells 		}
1285a813276SDavid Howells 		/* If the file is being filled locally, allow inter-write
1295a813276SDavid Howells 		 * spaces to be merged into writes.  If it's not, only write
1305a813276SDavid Howells 		 * back what the user gives us.
1315a813276SDavid Howells 		 */
1325a813276SDavid Howells 		if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
1335a813276SDavid Howells 		    (to < f || from > t))
1344343d008SDavid Howells 			goto flush_conflicting_write;
1354343d008SDavid Howells 		if (from < f)
1364343d008SDavid Howells 			f = from;
1374343d008SDavid Howells 		if (to > t)
1384343d008SDavid Howells 			t = to;
1394343d008SDavid Howells 	} else {
1404343d008SDavid Howells 		f = from;
1414343d008SDavid Howells 		t = to;
14231143d5dSDavid Howells 	}
14331143d5dSDavid Howells 
1444343d008SDavid Howells 	priv = (unsigned long)t << AFS_PRIV_SHIFT;
1454343d008SDavid Howells 	priv |= f;
14613524ab3SDavid Howells 	trace_afs_page_dirty(vnode, tracepoint_string("begin"),
14713524ab3SDavid Howells 			     page->index, priv);
14831143d5dSDavid Howells 	SetPagePrivate(page);
1494343d008SDavid Howells 	set_page_private(page, priv);
1504343d008SDavid Howells 	_leave(" = 0");
15131143d5dSDavid Howells 	return 0;
15231143d5dSDavid Howells 
1534343d008SDavid Howells 	/* The previous write and this write aren't adjacent or overlapping, so
1544343d008SDavid Howells 	 * flush the page out.
1554343d008SDavid Howells 	 */
1564343d008SDavid Howells flush_conflicting_write:
15731143d5dSDavid Howells 	_debug("flush conflict");
1584343d008SDavid Howells 	ret = write_one_page(page);
15931143d5dSDavid Howells 	if (ret < 0) {
16031143d5dSDavid Howells 		_leave(" = %d", ret);
16131143d5dSDavid Howells 		return ret;
16231143d5dSDavid Howells 	}
16331143d5dSDavid Howells 
1644343d008SDavid Howells 	ret = lock_page_killable(page);
1654343d008SDavid Howells 	if (ret < 0) {
1664343d008SDavid Howells 		_leave(" = %d", ret);
1674343d008SDavid Howells 		return ret;
1684343d008SDavid Howells 	}
16931143d5dSDavid Howells 	goto try_again;
17031143d5dSDavid Howells }
17131143d5dSDavid Howells 
17231143d5dSDavid Howells /*
17331143d5dSDavid Howells  * finalise part of a write to a page
17431143d5dSDavid Howells  */
17515b4650eSNick Piggin int afs_write_end(struct file *file, struct address_space *mapping,
17615b4650eSNick Piggin 		  loff_t pos, unsigned len, unsigned copied,
17715b4650eSNick Piggin 		  struct page *page, void *fsdata)
17831143d5dSDavid Howells {
179496ad9aaSAl Viro 	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
180215804a9SDavid Howells 	struct key *key = afs_file_key(file);
18131143d5dSDavid Howells 	loff_t i_size, maybe_i_size;
182e8e581a8SDavid Howells 	int ret;
18331143d5dSDavid Howells 
18415b4650eSNick Piggin 	_enter("{%x:%u},{%lx}",
18515b4650eSNick Piggin 	       vnode->fid.vid, vnode->fid.vnode, page->index);
18631143d5dSDavid Howells 
18715b4650eSNick Piggin 	maybe_i_size = pos + copied;
18831143d5dSDavid Howells 
18931143d5dSDavid Howells 	i_size = i_size_read(&vnode->vfs_inode);
19031143d5dSDavid Howells 	if (maybe_i_size > i_size) {
1914343d008SDavid Howells 		spin_lock(&vnode->wb_lock);
19231143d5dSDavid Howells 		i_size = i_size_read(&vnode->vfs_inode);
19331143d5dSDavid Howells 		if (maybe_i_size > i_size)
19431143d5dSDavid Howells 			i_size_write(&vnode->vfs_inode, maybe_i_size);
1954343d008SDavid Howells 		spin_unlock(&vnode->wb_lock);
19631143d5dSDavid Howells 	}
19731143d5dSDavid Howells 
198e8e581a8SDavid Howells 	if (!PageUptodate(page)) {
199e8e581a8SDavid Howells 		if (copied < len) {
200e8e581a8SDavid Howells 			/* Try and load any missing data from the server.  The
201e8e581a8SDavid Howells 			 * unmarshalling routine will take care of clearing any
202e8e581a8SDavid Howells 			 * bits that are beyond the EOF.
203e8e581a8SDavid Howells 			 */
204e8e581a8SDavid Howells 			ret = afs_fill_page(vnode, key, pos + copied,
205e8e581a8SDavid Howells 					    len - copied, page);
206e8e581a8SDavid Howells 			if (ret < 0)
207afae457dSDavid Howells 				goto out;
208e8e581a8SDavid Howells 		}
209e8e581a8SDavid Howells 		SetPageUptodate(page);
210e8e581a8SDavid Howells 	}
211e8e581a8SDavid Howells 
21231143d5dSDavid Howells 	set_page_dirty(page);
21331143d5dSDavid Howells 	if (PageDirty(page))
21431143d5dSDavid Howells 		_debug("dirtied");
215afae457dSDavid Howells 	ret = copied;
216afae457dSDavid Howells 
217afae457dSDavid Howells out:
21815b4650eSNick Piggin 	unlock_page(page);
21909cbfeafSKirill A. Shutemov 	put_page(page);
220afae457dSDavid Howells 	return ret;
22131143d5dSDavid Howells }
22231143d5dSDavid Howells 
22331143d5dSDavid Howells /*
22431143d5dSDavid Howells  * kill all the pages in the given range
22531143d5dSDavid Howells  */
2264343d008SDavid Howells static void afs_kill_pages(struct address_space *mapping,
22731143d5dSDavid Howells 			   pgoff_t first, pgoff_t last)
22831143d5dSDavid Howells {
2294343d008SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
23031143d5dSDavid Howells 	struct pagevec pv;
23131143d5dSDavid Howells 	unsigned count, loop;
23231143d5dSDavid Howells 
23331143d5dSDavid Howells 	_enter("{%x:%u},%lx-%lx",
23431143d5dSDavid Howells 	       vnode->fid.vid, vnode->fid.vnode, first, last);
23531143d5dSDavid Howells 
23686679820SMel Gorman 	pagevec_init(&pv);
23731143d5dSDavid Howells 
23831143d5dSDavid Howells 	do {
23931143d5dSDavid Howells 		_debug("kill %lx-%lx", first, last);
24031143d5dSDavid Howells 
24131143d5dSDavid Howells 		count = last - first + 1;
24231143d5dSDavid Howells 		if (count > PAGEVEC_SIZE)
24331143d5dSDavid Howells 			count = PAGEVEC_SIZE;
2444343d008SDavid Howells 		pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
24531143d5dSDavid Howells 		ASSERTCMP(pv.nr, ==, count);
24631143d5dSDavid Howells 
24731143d5dSDavid Howells 		for (loop = 0; loop < count; loop++) {
2487286a35eSDavid Howells 			struct page *page = pv.pages[loop];
2497286a35eSDavid Howells 			ClearPageUptodate(page);
2507286a35eSDavid Howells 			SetPageError(page);
2514343d008SDavid Howells 			end_page_writeback(page);
2524343d008SDavid Howells 			if (page->index >= first)
2534343d008SDavid Howells 				first = page->index + 1;
2544343d008SDavid Howells 			lock_page(page);
2554343d008SDavid Howells 			generic_error_remove_page(mapping, page);
2564343d008SDavid Howells 		}
2574343d008SDavid Howells 
2584343d008SDavid Howells 		__pagevec_release(&pv);
2594343d008SDavid Howells 	} while (first <= last);
2604343d008SDavid Howells 
2614343d008SDavid Howells 	_leave("");
2624343d008SDavid Howells }
2634343d008SDavid Howells 
2644343d008SDavid Howells /*
2654343d008SDavid Howells  * Redirty all the pages in a given range.
2664343d008SDavid Howells  */
2674343d008SDavid Howells static void afs_redirty_pages(struct writeback_control *wbc,
2684343d008SDavid Howells 			      struct address_space *mapping,
2694343d008SDavid Howells 			      pgoff_t first, pgoff_t last)
2704343d008SDavid Howells {
2714343d008SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
2724343d008SDavid Howells 	struct pagevec pv;
2734343d008SDavid Howells 	unsigned count, loop;
2744343d008SDavid Howells 
2754343d008SDavid Howells 	_enter("{%x:%u},%lx-%lx",
2764343d008SDavid Howells 	       vnode->fid.vid, vnode->fid.vnode, first, last);
2774343d008SDavid Howells 
278487e2c9fSLinus Torvalds 	pagevec_init(&pv);
2794343d008SDavid Howells 
2804343d008SDavid Howells 	do {
2814343d008SDavid Howells 		_debug("redirty %lx-%lx", first, last);
2824343d008SDavid Howells 
2834343d008SDavid Howells 		count = last - first + 1;
2844343d008SDavid Howells 		if (count > PAGEVEC_SIZE)
2854343d008SDavid Howells 			count = PAGEVEC_SIZE;
2864343d008SDavid Howells 		pv.nr = find_get_pages_contig(mapping, first, count, pv.pages);
2874343d008SDavid Howells 		ASSERTCMP(pv.nr, ==, count);
2884343d008SDavid Howells 
2894343d008SDavid Howells 		for (loop = 0; loop < count; loop++) {
2904343d008SDavid Howells 			struct page *page = pv.pages[loop];
2914343d008SDavid Howells 
2924343d008SDavid Howells 			redirty_page_for_writepage(wbc, page);
2937286a35eSDavid Howells 			end_page_writeback(page);
2947286a35eSDavid Howells 			if (page->index >= first)
2957286a35eSDavid Howells 				first = page->index + 1;
29631143d5dSDavid Howells 		}
29731143d5dSDavid Howells 
29831143d5dSDavid Howells 		__pagevec_release(&pv);
2994343d008SDavid Howells 	} while (first <= last);
30031143d5dSDavid Howells 
30131143d5dSDavid Howells 	_leave("");
30231143d5dSDavid Howells }
30331143d5dSDavid Howells 
30431143d5dSDavid Howells /*
305d2ddc776SDavid Howells  * write to a file
30631143d5dSDavid Howells  */
3074343d008SDavid Howells static int afs_store_data(struct address_space *mapping,
3084343d008SDavid Howells 			  pgoff_t first, pgoff_t last,
309d2ddc776SDavid Howells 			  unsigned offset, unsigned to)
31031143d5dSDavid Howells {
3114343d008SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
312d2ddc776SDavid Howells 	struct afs_fs_cursor fc;
3134343d008SDavid Howells 	struct afs_wb_key *wbk = NULL;
3144343d008SDavid Howells 	struct list_head *p;
3154343d008SDavid Howells 	int ret = -ENOKEY, ret2;
316d2ddc776SDavid Howells 
3174343d008SDavid Howells 	_enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
318d2ddc776SDavid Howells 	       vnode->volume->name,
319d2ddc776SDavid Howells 	       vnode->fid.vid,
320d2ddc776SDavid Howells 	       vnode->fid.vnode,
321d2ddc776SDavid Howells 	       vnode->fid.unique,
322d2ddc776SDavid Howells 	       first, last, offset, to);
323d2ddc776SDavid Howells 
3244343d008SDavid Howells 	spin_lock(&vnode->wb_lock);
3254343d008SDavid Howells 	p = vnode->wb_keys.next;
3264343d008SDavid Howells 
3274343d008SDavid Howells 	/* Iterate through the list looking for a valid key to use. */
3284343d008SDavid Howells try_next_key:
3294343d008SDavid Howells 	while (p != &vnode->wb_keys) {
3304343d008SDavid Howells 		wbk = list_entry(p, struct afs_wb_key, vnode_link);
3314343d008SDavid Howells 		_debug("wbk %u", key_serial(wbk->key));
3324343d008SDavid Howells 		ret2 = key_validate(wbk->key);
3334343d008SDavid Howells 		if (ret2 == 0)
3344343d008SDavid Howells 			goto found_key;
3354343d008SDavid Howells 		if (ret == -ENOKEY)
3364343d008SDavid Howells 			ret = ret2;
3374343d008SDavid Howells 		p = p->next;
3384343d008SDavid Howells 	}
3394343d008SDavid Howells 
3404343d008SDavid Howells 	spin_unlock(&vnode->wb_lock);
3414343d008SDavid Howells 	afs_put_wb_key(wbk);
3424343d008SDavid Howells 	_leave(" = %d [no keys]", ret);
3434343d008SDavid Howells 	return ret;
3444343d008SDavid Howells 
3454343d008SDavid Howells found_key:
3464343d008SDavid Howells 	refcount_inc(&wbk->usage);
3474343d008SDavid Howells 	spin_unlock(&vnode->wb_lock);
3484343d008SDavid Howells 
3494343d008SDavid Howells 	_debug("USE WB KEY %u", key_serial(wbk->key));
3504343d008SDavid Howells 
351d2ddc776SDavid Howells 	ret = -ERESTARTSYS;
3524343d008SDavid Howells 	if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
353d2ddc776SDavid Howells 		while (afs_select_fileserver(&fc)) {
35468251f0aSDavid Howells 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
3554343d008SDavid Howells 			afs_fs_store_data(&fc, mapping, first, last, offset, to);
356d2ddc776SDavid Howells 		}
357d2ddc776SDavid Howells 
358d2ddc776SDavid Howells 		afs_check_for_remote_deletion(&fc, fc.vnode);
359d2ddc776SDavid Howells 		afs_vnode_commit_status(&fc, vnode, fc.cb_break);
360d2ddc776SDavid Howells 		ret = afs_end_vnode_operation(&fc);
361d2ddc776SDavid Howells 	}
362d2ddc776SDavid Howells 
3634343d008SDavid Howells 	switch (ret) {
36476a5cb6fSDavid Howells 	case 0:
36576a5cb6fSDavid Howells 		afs_stat_v(vnode, n_stores);
36676a5cb6fSDavid Howells 		atomic_long_add((last * PAGE_SIZE + to) -
36776a5cb6fSDavid Howells 				(first * PAGE_SIZE + offset),
36876a5cb6fSDavid Howells 				&afs_v2net(vnode)->n_store_bytes);
36976a5cb6fSDavid Howells 		break;
3704343d008SDavid Howells 	case -EACCES:
3714343d008SDavid Howells 	case -EPERM:
3724343d008SDavid Howells 	case -ENOKEY:
3734343d008SDavid Howells 	case -EKEYEXPIRED:
3744343d008SDavid Howells 	case -EKEYREJECTED:
3754343d008SDavid Howells 	case -EKEYREVOKED:
3764343d008SDavid Howells 		_debug("next");
3774343d008SDavid Howells 		spin_lock(&vnode->wb_lock);
3784343d008SDavid Howells 		p = wbk->vnode_link.next;
3794343d008SDavid Howells 		afs_put_wb_key(wbk);
3804343d008SDavid Howells 		goto try_next_key;
3814343d008SDavid Howells 	}
3824343d008SDavid Howells 
3834343d008SDavid Howells 	afs_put_wb_key(wbk);
384d2ddc776SDavid Howells 	_leave(" = %d", ret);
385d2ddc776SDavid Howells 	return ret;
386d2ddc776SDavid Howells }
387d2ddc776SDavid Howells 
388d2ddc776SDavid Howells /*
3894343d008SDavid Howells  * Synchronously write back the locked page and any subsequent non-locked dirty
3904343d008SDavid Howells  * pages.
39131143d5dSDavid Howells  */
3924343d008SDavid Howells static int afs_write_back_from_locked_page(struct address_space *mapping,
3934343d008SDavid Howells 					   struct writeback_control *wbc,
3944343d008SDavid Howells 					   struct page *primary_page,
3954343d008SDavid Howells 					   pgoff_t final_page)
39631143d5dSDavid Howells {
39713524ab3SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
39831143d5dSDavid Howells 	struct page *pages[8], *page;
3994343d008SDavid Howells 	unsigned long count, priv;
4004343d008SDavid Howells 	unsigned n, offset, to, f, t;
40131143d5dSDavid Howells 	pgoff_t start, first, last;
40231143d5dSDavid Howells 	int loop, ret;
40331143d5dSDavid Howells 
40431143d5dSDavid Howells 	_enter(",%lx", primary_page->index);
40531143d5dSDavid Howells 
40631143d5dSDavid Howells 	count = 1;
40731143d5dSDavid Howells 	if (test_set_page_writeback(primary_page))
40831143d5dSDavid Howells 		BUG();
40931143d5dSDavid Howells 
4104343d008SDavid Howells 	/* Find all consecutive lockable dirty pages that have contiguous
4114343d008SDavid Howells 	 * written regions, stopping when we find a page that is not
4124343d008SDavid Howells 	 * immediately lockable, is not dirty or is missing, or we reach the
4134343d008SDavid Howells 	 * end of the range.
4144343d008SDavid Howells 	 */
41531143d5dSDavid Howells 	start = primary_page->index;
4164343d008SDavid Howells 	priv = page_private(primary_page);
4174343d008SDavid Howells 	offset = priv & AFS_PRIV_MAX;
4184343d008SDavid Howells 	to = priv >> AFS_PRIV_SHIFT;
41913524ab3SDavid Howells 	trace_afs_page_dirty(vnode, tracepoint_string("store"),
42013524ab3SDavid Howells 			     primary_page->index, priv);
4214343d008SDavid Howells 
4224343d008SDavid Howells 	WARN_ON(offset == to);
42313524ab3SDavid Howells 	if (offset == to)
42413524ab3SDavid Howells 		trace_afs_page_dirty(vnode, tracepoint_string("WARN"),
42513524ab3SDavid Howells 				     primary_page->index, priv);
4264343d008SDavid Howells 
4275a813276SDavid Howells 	if (start >= final_page ||
4285a813276SDavid Howells 	    (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
42931143d5dSDavid Howells 		goto no_more;
4304343d008SDavid Howells 
43131143d5dSDavid Howells 	start++;
43231143d5dSDavid Howells 	do {
43331143d5dSDavid Howells 		_debug("more %lx [%lx]", start, count);
4344343d008SDavid Howells 		n = final_page - start + 1;
43531143d5dSDavid Howells 		if (n > ARRAY_SIZE(pages))
43631143d5dSDavid Howells 			n = ARRAY_SIZE(pages);
4374343d008SDavid Howells 		n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages);
43831143d5dSDavid Howells 		_debug("fgpc %u", n);
43931143d5dSDavid Howells 		if (n == 0)
44031143d5dSDavid Howells 			goto no_more;
44131143d5dSDavid Howells 		if (pages[0]->index != start) {
4429d577b6aSDavid Howells 			do {
4439d577b6aSDavid Howells 				put_page(pages[--n]);
4449d577b6aSDavid Howells 			} while (n > 0);
44531143d5dSDavid Howells 			goto no_more;
44631143d5dSDavid Howells 		}
44731143d5dSDavid Howells 
44831143d5dSDavid Howells 		for (loop = 0; loop < n; loop++) {
44931143d5dSDavid Howells 			page = pages[loop];
4505a813276SDavid Howells 			if (to != PAGE_SIZE &&
4515a813276SDavid Howells 			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
4525a813276SDavid Howells 				break;
4534343d008SDavid Howells 			if (page->index > final_page)
45431143d5dSDavid Howells 				break;
455529ae9aaSNick Piggin 			if (!trylock_page(page))
45631143d5dSDavid Howells 				break;
4574343d008SDavid Howells 			if (!PageDirty(page) || PageWriteback(page)) {
45831143d5dSDavid Howells 				unlock_page(page);
45931143d5dSDavid Howells 				break;
46031143d5dSDavid Howells 			}
4614343d008SDavid Howells 
4624343d008SDavid Howells 			priv = page_private(page);
4634343d008SDavid Howells 			f = priv & AFS_PRIV_MAX;
4644343d008SDavid Howells 			t = priv >> AFS_PRIV_SHIFT;
4655a813276SDavid Howells 			if (f != 0 &&
4665a813276SDavid Howells 			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
4674343d008SDavid Howells 				unlock_page(page);
4684343d008SDavid Howells 				break;
4694343d008SDavid Howells 			}
4704343d008SDavid Howells 			to = t;
4714343d008SDavid Howells 
47213524ab3SDavid Howells 			trace_afs_page_dirty(vnode, tracepoint_string("store+"),
47313524ab3SDavid Howells 					     page->index, priv);
47413524ab3SDavid Howells 
47531143d5dSDavid Howells 			if (!clear_page_dirty_for_io(page))
47631143d5dSDavid Howells 				BUG();
47731143d5dSDavid Howells 			if (test_set_page_writeback(page))
47831143d5dSDavid Howells 				BUG();
47931143d5dSDavid Howells 			unlock_page(page);
48031143d5dSDavid Howells 			put_page(page);
48131143d5dSDavid Howells 		}
48231143d5dSDavid Howells 		count += loop;
48331143d5dSDavid Howells 		if (loop < n) {
48431143d5dSDavid Howells 			for (; loop < n; loop++)
48531143d5dSDavid Howells 				put_page(pages[loop]);
48631143d5dSDavid Howells 			goto no_more;
48731143d5dSDavid Howells 		}
48831143d5dSDavid Howells 
48931143d5dSDavid Howells 		start += loop;
4904343d008SDavid Howells 	} while (start <= final_page && count < 65536);
49131143d5dSDavid Howells 
49231143d5dSDavid Howells no_more:
4934343d008SDavid Howells 	/* We now have a contiguous set of dirty pages, each with writeback
4944343d008SDavid Howells 	 * set; the first page is still locked at this point, but all the rest
4954343d008SDavid Howells 	 * have been unlocked.
4964343d008SDavid Howells 	 */
4974343d008SDavid Howells 	unlock_page(primary_page);
4984343d008SDavid Howells 
49931143d5dSDavid Howells 	first = primary_page->index;
50031143d5dSDavid Howells 	last = first + count - 1;
50131143d5dSDavid Howells 
50231143d5dSDavid Howells 	_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
50331143d5dSDavid Howells 
5044343d008SDavid Howells 	ret = afs_store_data(mapping, first, last, offset, to);
50531143d5dSDavid Howells 	switch (ret) {
5064343d008SDavid Howells 	case 0:
5074343d008SDavid Howells 		ret = count;
5084343d008SDavid Howells 		break;
5094343d008SDavid Howells 
5104343d008SDavid Howells 	default:
5114343d008SDavid Howells 		pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
5124343d008SDavid Howells 		/* Fall through */
5134343d008SDavid Howells 	case -EACCES:
5144343d008SDavid Howells 	case -EPERM:
5154343d008SDavid Howells 	case -ENOKEY:
5164343d008SDavid Howells 	case -EKEYEXPIRED:
5174343d008SDavid Howells 	case -EKEYREJECTED:
5184343d008SDavid Howells 	case -EKEYREVOKED:
5194343d008SDavid Howells 		afs_redirty_pages(wbc, mapping, first, last);
5204343d008SDavid Howells 		mapping_set_error(mapping, ret);
5214343d008SDavid Howells 		break;
5224343d008SDavid Howells 
52331143d5dSDavid Howells 	case -EDQUOT:
52431143d5dSDavid Howells 	case -ENOSPC:
5254343d008SDavid Howells 		afs_redirty_pages(wbc, mapping, first, last);
5264343d008SDavid Howells 		mapping_set_error(mapping, -ENOSPC);
52731143d5dSDavid Howells 		break;
5284343d008SDavid Howells 
52931143d5dSDavid Howells 	case -EROFS:
53031143d5dSDavid Howells 	case -EIO:
53131143d5dSDavid Howells 	case -EREMOTEIO:
53231143d5dSDavid Howells 	case -EFBIG:
53331143d5dSDavid Howells 	case -ENOENT:
53431143d5dSDavid Howells 	case -ENOMEDIUM:
53531143d5dSDavid Howells 	case -ENXIO:
536f51375cdSDavid Howells 		trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
5374343d008SDavid Howells 		afs_kill_pages(mapping, first, last);
5384343d008SDavid Howells 		mapping_set_error(mapping, ret);
53931143d5dSDavid Howells 		break;
54031143d5dSDavid Howells 	}
54131143d5dSDavid Howells 
54231143d5dSDavid Howells 	_leave(" = %d", ret);
54331143d5dSDavid Howells 	return ret;
54431143d5dSDavid Howells }
54531143d5dSDavid Howells 
54631143d5dSDavid Howells /*
54731143d5dSDavid Howells  * write a page back to the server
54831143d5dSDavid Howells  * - the caller locked the page for us
54931143d5dSDavid Howells  */
55031143d5dSDavid Howells int afs_writepage(struct page *page, struct writeback_control *wbc)
55131143d5dSDavid Howells {
55231143d5dSDavid Howells 	int ret;
55331143d5dSDavid Howells 
55431143d5dSDavid Howells 	_enter("{%lx},", page->index);
55531143d5dSDavid Howells 
5564343d008SDavid Howells 	ret = afs_write_back_from_locked_page(page->mapping, wbc, page,
5574343d008SDavid Howells 					      wbc->range_end >> PAGE_SHIFT);
55831143d5dSDavid Howells 	if (ret < 0) {
55931143d5dSDavid Howells 		_leave(" = %d", ret);
56031143d5dSDavid Howells 		return 0;
56131143d5dSDavid Howells 	}
56231143d5dSDavid Howells 
56331143d5dSDavid Howells 	wbc->nr_to_write -= ret;
56431143d5dSDavid Howells 
56531143d5dSDavid Howells 	_leave(" = 0");
56631143d5dSDavid Howells 	return 0;
56731143d5dSDavid Howells }
56831143d5dSDavid Howells 
56931143d5dSDavid Howells /*
57031143d5dSDavid Howells  * write a region of pages back to the server
57131143d5dSDavid Howells  */
572c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping,
57331143d5dSDavid Howells 				 struct writeback_control *wbc,
57431143d5dSDavid Howells 				 pgoff_t index, pgoff_t end, pgoff_t *_next)
57531143d5dSDavid Howells {
57631143d5dSDavid Howells 	struct page *page;
57731143d5dSDavid Howells 	int ret, n;
57831143d5dSDavid Howells 
57931143d5dSDavid Howells 	_enter(",,%lx,%lx,", index, end);
58031143d5dSDavid Howells 
58131143d5dSDavid Howells 	do {
582aef6e415SJan Kara 		n = find_get_pages_range_tag(mapping, &index, end,
583aef6e415SJan Kara 					PAGECACHE_TAG_DIRTY, 1, &page);
58431143d5dSDavid Howells 		if (!n)
58531143d5dSDavid Howells 			break;
58631143d5dSDavid Howells 
58731143d5dSDavid Howells 		_debug("wback %lx", page->index);
58831143d5dSDavid Howells 
589b93b0163SMatthew Wilcox 		/*
590b93b0163SMatthew Wilcox 		 * at this point we hold neither the i_pages lock nor the
591b93b0163SMatthew Wilcox 		 * page lock: the page may be truncated or invalidated
592b93b0163SMatthew Wilcox 		 * (changing page->mapping to NULL), or even swizzled
593b93b0163SMatthew Wilcox 		 * back from swapper_space to tmpfs file mapping
59431143d5dSDavid Howells 		 */
5954343d008SDavid Howells 		ret = lock_page_killable(page);
5964343d008SDavid Howells 		if (ret < 0) {
5974343d008SDavid Howells 			put_page(page);
5984343d008SDavid Howells 			_leave(" = %d", ret);
5994343d008SDavid Howells 			return ret;
6004343d008SDavid Howells 		}
60131143d5dSDavid Howells 
602c5051c7bSDavid Howells 		if (page->mapping != mapping || !PageDirty(page)) {
60331143d5dSDavid Howells 			unlock_page(page);
60409cbfeafSKirill A. Shutemov 			put_page(page);
60531143d5dSDavid Howells 			continue;
60631143d5dSDavid Howells 		}
60731143d5dSDavid Howells 
608c5051c7bSDavid Howells 		if (PageWriteback(page)) {
609c5051c7bSDavid Howells 			unlock_page(page);
61031143d5dSDavid Howells 			if (wbc->sync_mode != WB_SYNC_NONE)
61131143d5dSDavid Howells 				wait_on_page_writeback(page);
61229c8bbbdSDavid Howells 			put_page(page);
61331143d5dSDavid Howells 			continue;
61431143d5dSDavid Howells 		}
61531143d5dSDavid Howells 
61665a15109SDavid Howells 		if (!clear_page_dirty_for_io(page))
61765a15109SDavid Howells 			BUG();
6184343d008SDavid Howells 		ret = afs_write_back_from_locked_page(mapping, wbc, page, end);
61909cbfeafSKirill A. Shutemov 		put_page(page);
62031143d5dSDavid Howells 		if (ret < 0) {
62131143d5dSDavid Howells 			_leave(" = %d", ret);
62231143d5dSDavid Howells 			return ret;
62331143d5dSDavid Howells 		}
62431143d5dSDavid Howells 
62531143d5dSDavid Howells 		wbc->nr_to_write -= ret;
62631143d5dSDavid Howells 
62731143d5dSDavid Howells 		cond_resched();
62831143d5dSDavid Howells 	} while (index < end && wbc->nr_to_write > 0);
62931143d5dSDavid Howells 
63031143d5dSDavid Howells 	*_next = index;
63131143d5dSDavid Howells 	_leave(" = 0 [%lx]", *_next);
63231143d5dSDavid Howells 	return 0;
63331143d5dSDavid Howells }
63431143d5dSDavid Howells 
63531143d5dSDavid Howells /*
63631143d5dSDavid Howells  * write some of the pending data back to the server
63731143d5dSDavid Howells  */
63831143d5dSDavid Howells int afs_writepages(struct address_space *mapping,
63931143d5dSDavid Howells 		   struct writeback_control *wbc)
64031143d5dSDavid Howells {
64131143d5dSDavid Howells 	pgoff_t start, end, next;
64231143d5dSDavid Howells 	int ret;
64331143d5dSDavid Howells 
64431143d5dSDavid Howells 	_enter("");
64531143d5dSDavid Howells 
64631143d5dSDavid Howells 	if (wbc->range_cyclic) {
64731143d5dSDavid Howells 		start = mapping->writeback_index;
64831143d5dSDavid Howells 		end = -1;
64931143d5dSDavid Howells 		ret = afs_writepages_region(mapping, wbc, start, end, &next);
6501b430beeSWu Fengguang 		if (start > 0 && wbc->nr_to_write > 0 && ret == 0)
65131143d5dSDavid Howells 			ret = afs_writepages_region(mapping, wbc, 0, start,
65231143d5dSDavid Howells 						    &next);
65331143d5dSDavid Howells 		mapping->writeback_index = next;
65431143d5dSDavid Howells 	} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
65509cbfeafSKirill A. Shutemov 		end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
65631143d5dSDavid Howells 		ret = afs_writepages_region(mapping, wbc, 0, end, &next);
65731143d5dSDavid Howells 		if (wbc->nr_to_write > 0)
65831143d5dSDavid Howells 			mapping->writeback_index = next;
65931143d5dSDavid Howells 	} else {
66009cbfeafSKirill A. Shutemov 		start = wbc->range_start >> PAGE_SHIFT;
66109cbfeafSKirill A. Shutemov 		end = wbc->range_end >> PAGE_SHIFT;
66231143d5dSDavid Howells 		ret = afs_writepages_region(mapping, wbc, start, end, &next);
66331143d5dSDavid Howells 	}
66431143d5dSDavid Howells 
66531143d5dSDavid Howells 	_leave(" = %d", ret);
66631143d5dSDavid Howells 	return ret;
66731143d5dSDavid Howells }
66831143d5dSDavid Howells 
66931143d5dSDavid Howells /*
67031143d5dSDavid Howells  * completion of write to server
67131143d5dSDavid Howells  */
67231143d5dSDavid Howells void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
67331143d5dSDavid Howells {
67431143d5dSDavid Howells 	struct pagevec pv;
67513524ab3SDavid Howells 	unsigned long priv;
67631143d5dSDavid Howells 	unsigned count, loop;
67731143d5dSDavid Howells 	pgoff_t first = call->first, last = call->last;
67831143d5dSDavid Howells 
67931143d5dSDavid Howells 	_enter("{%x:%u},{%lx-%lx}",
68031143d5dSDavid Howells 	       vnode->fid.vid, vnode->fid.vnode, first, last);
68131143d5dSDavid Howells 
68286679820SMel Gorman 	pagevec_init(&pv);
68331143d5dSDavid Howells 
68431143d5dSDavid Howells 	do {
6855bbf5d39SDavid Howells 		_debug("done %lx-%lx", first, last);
68631143d5dSDavid Howells 
68731143d5dSDavid Howells 		count = last - first + 1;
68831143d5dSDavid Howells 		if (count > PAGEVEC_SIZE)
68931143d5dSDavid Howells 			count = PAGEVEC_SIZE;
6904343d008SDavid Howells 		pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
6914343d008SDavid Howells 					      first, count, pv.pages);
69231143d5dSDavid Howells 		ASSERTCMP(pv.nr, ==, count);
69331143d5dSDavid Howells 
69431143d5dSDavid Howells 		for (loop = 0; loop < count; loop++) {
69513524ab3SDavid Howells 			priv = page_private(pv.pages[loop]);
69613524ab3SDavid Howells 			trace_afs_page_dirty(vnode, tracepoint_string("clear"),
69713524ab3SDavid Howells 					     pv.pages[loop]->index, priv);
6984343d008SDavid Howells 			set_page_private(pv.pages[loop], 0);
6994343d008SDavid Howells 			end_page_writeback(pv.pages[loop]);
70031143d5dSDavid Howells 		}
70131143d5dSDavid Howells 		first += count;
70231143d5dSDavid Howells 		__pagevec_release(&pv);
7035bbf5d39SDavid Howells 	} while (first <= last);
70431143d5dSDavid Howells 
7054343d008SDavid Howells 	afs_prune_wb_keys(vnode);
70631143d5dSDavid Howells 	_leave("");
70731143d5dSDavid Howells }
70831143d5dSDavid Howells 
70931143d5dSDavid Howells /*
71031143d5dSDavid Howells  * write to an AFS file
71131143d5dSDavid Howells  */
71250b5551dSAl Viro ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
71331143d5dSDavid Howells {
714496ad9aaSAl Viro 	struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
71531143d5dSDavid Howells 	ssize_t result;
71650b5551dSAl Viro 	size_t count = iov_iter_count(from);
71731143d5dSDavid Howells 
71850b5551dSAl Viro 	_enter("{%x.%u},{%zu},",
71950b5551dSAl Viro 	       vnode->fid.vid, vnode->fid.vnode, count);
72031143d5dSDavid Howells 
72131143d5dSDavid Howells 	if (IS_SWAPFILE(&vnode->vfs_inode)) {
72231143d5dSDavid Howells 		printk(KERN_INFO
72331143d5dSDavid Howells 		       "AFS: Attempt to write to active swap file!\n");
72431143d5dSDavid Howells 		return -EBUSY;
72531143d5dSDavid Howells 	}
72631143d5dSDavid Howells 
72731143d5dSDavid Howells 	if (!count)
72831143d5dSDavid Howells 		return 0;
72931143d5dSDavid Howells 
73050b5551dSAl Viro 	result = generic_file_write_iter(iocb, from);
73131143d5dSDavid Howells 
73231143d5dSDavid Howells 	_leave(" = %zd", result);
73331143d5dSDavid Howells 	return result;
73431143d5dSDavid Howells }
73531143d5dSDavid Howells 
73631143d5dSDavid Howells /*
73731143d5dSDavid Howells  * flush any dirty pages for this process, and check for write errors.
73831143d5dSDavid Howells  * - the return status from this call provides a reliable indication of
73931143d5dSDavid Howells  *   whether any write errors occurred for this process.
74031143d5dSDavid Howells  */
74102c24a82SJosef Bacik int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
74231143d5dSDavid Howells {
7433c981bfcSAl Viro 	struct inode *inode = file_inode(file);
7443c981bfcSAl Viro 	struct afs_vnode *vnode = AFS_FS_I(inode);
74531143d5dSDavid Howells 
7463c981bfcSAl Viro 	_enter("{%x:%u},{n=%pD},%d",
7473c981bfcSAl Viro 	       vnode->fid.vid, vnode->fid.vnode, file,
74831143d5dSDavid Howells 	       datasync);
74931143d5dSDavid Howells 
7504343d008SDavid Howells 	return file_write_and_wait_range(file, start, end);
75131143d5dSDavid Howells }
7529b3f26c9SDavid Howells 
7539b3f26c9SDavid Howells /*
7549b3f26c9SDavid Howells  * notification that a previously read-only page is about to become writable
7559b3f26c9SDavid Howells  * - if it returns an error, the caller will deliver a bus error signal
7569b3f26c9SDavid Howells  */
7570722f186SSouptick Joarder vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
7589b3f26c9SDavid Howells {
7591cf7a151SDavid Howells 	struct file *file = vmf->vma->vm_file;
7601cf7a151SDavid Howells 	struct inode *inode = file_inode(file);
7611cf7a151SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(inode);
7621cf7a151SDavid Howells 	unsigned long priv;
7639b3f26c9SDavid Howells 
7649b3f26c9SDavid Howells 	_enter("{{%x:%u}},{%lx}",
7651cf7a151SDavid Howells 	       vnode->fid.vid, vnode->fid.vnode, vmf->page->index);
7669b3f26c9SDavid Howells 
7671cf7a151SDavid Howells 	sb_start_pagefault(inode->i_sb);
7681cf7a151SDavid Howells 
7691cf7a151SDavid Howells 	/* Wait for the page to be written to the cache before we allow it to
7701cf7a151SDavid Howells 	 * be modified.  We then assume the entire page will need writing back.
7711cf7a151SDavid Howells 	 */
7729b3f26c9SDavid Howells #ifdef CONFIG_AFS_FSCACHE
7731cf7a151SDavid Howells 	fscache_wait_on_page_write(vnode->cache, vmf->page);
7749b3f26c9SDavid Howells #endif
7759b3f26c9SDavid Howells 
7761cf7a151SDavid Howells 	if (PageWriteback(vmf->page) &&
7771cf7a151SDavid Howells 	    wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
7781cf7a151SDavid Howells 		return VM_FAULT_RETRY;
7791cf7a151SDavid Howells 
7801cf7a151SDavid Howells 	if (lock_page_killable(vmf->page) < 0)
7811cf7a151SDavid Howells 		return VM_FAULT_RETRY;
7821cf7a151SDavid Howells 
7831cf7a151SDavid Howells 	/* We mustn't change page->private until writeback is complete as that
7841cf7a151SDavid Howells 	 * details the portion of the page we need to write back and we might
7851cf7a151SDavid Howells 	 * need to redirty the page if there's a problem.
7861cf7a151SDavid Howells 	 */
7871cf7a151SDavid Howells 	wait_on_page_writeback(vmf->page);
7881cf7a151SDavid Howells 
7891cf7a151SDavid Howells 	priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */
7901cf7a151SDavid Howells 	priv |= 0; /* From */
79113524ab3SDavid Howells 	trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"),
79213524ab3SDavid Howells 			     vmf->page->index, priv);
7931cf7a151SDavid Howells 	SetPagePrivate(vmf->page);
7941cf7a151SDavid Howells 	set_page_private(vmf->page, priv);
7951cf7a151SDavid Howells 
7961cf7a151SDavid Howells 	sb_end_pagefault(inode->i_sb);
7971cf7a151SDavid Howells 	return VM_FAULT_LOCKED;
7989b3f26c9SDavid Howells }
7994343d008SDavid Howells 
8004343d008SDavid Howells /*
8014343d008SDavid Howells  * Prune the keys cached for writeback.  The caller must hold vnode->wb_lock.
8024343d008SDavid Howells  */
8034343d008SDavid Howells void afs_prune_wb_keys(struct afs_vnode *vnode)
8044343d008SDavid Howells {
8054343d008SDavid Howells 	LIST_HEAD(graveyard);
8064343d008SDavid Howells 	struct afs_wb_key *wbk, *tmp;
8074343d008SDavid Howells 
8084343d008SDavid Howells 	/* Discard unused keys */
8094343d008SDavid Howells 	spin_lock(&vnode->wb_lock);
8104343d008SDavid Howells 
8114343d008SDavid Howells 	if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) &&
8124343d008SDavid Howells 	    !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) {
8134343d008SDavid Howells 		list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) {
8144343d008SDavid Howells 			if (refcount_read(&wbk->usage) == 1)
8154343d008SDavid Howells 				list_move(&wbk->vnode_link, &graveyard);
8164343d008SDavid Howells 		}
8174343d008SDavid Howells 	}
8184343d008SDavid Howells 
8194343d008SDavid Howells 	spin_unlock(&vnode->wb_lock);
8204343d008SDavid Howells 
8214343d008SDavid Howells 	while (!list_empty(&graveyard)) {
8224343d008SDavid Howells 		wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link);
8234343d008SDavid Howells 		list_del(&wbk->vnode_link);
8244343d008SDavid Howells 		afs_put_wb_key(wbk);
8254343d008SDavid Howells 	}
8264343d008SDavid Howells }
8274343d008SDavid Howells 
8284343d008SDavid Howells /*
8294343d008SDavid Howells  * Clean up a page during invalidation.
8304343d008SDavid Howells  */
8314343d008SDavid Howells int afs_launder_page(struct page *page)
8324343d008SDavid Howells {
8334343d008SDavid Howells 	struct address_space *mapping = page->mapping;
8344343d008SDavid Howells 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
8354343d008SDavid Howells 	unsigned long priv;
8364343d008SDavid Howells 	unsigned int f, t;
8374343d008SDavid Howells 	int ret = 0;
8384343d008SDavid Howells 
8394343d008SDavid Howells 	_enter("{%lx}", page->index);
8404343d008SDavid Howells 
8414343d008SDavid Howells 	priv = page_private(page);
8424343d008SDavid Howells 	if (clear_page_dirty_for_io(page)) {
8434343d008SDavid Howells 		f = 0;
8444343d008SDavid Howells 		t = PAGE_SIZE;
8454343d008SDavid Howells 		if (PagePrivate(page)) {
8464343d008SDavid Howells 			f = priv & AFS_PRIV_MAX;
8474343d008SDavid Howells 			t = priv >> AFS_PRIV_SHIFT;
8484343d008SDavid Howells 		}
8494343d008SDavid Howells 
85013524ab3SDavid Howells 		trace_afs_page_dirty(vnode, tracepoint_string("launder"),
85113524ab3SDavid Howells 				     page->index, priv);
8524343d008SDavid Howells 		ret = afs_store_data(mapping, page->index, page->index, t, f);
8534343d008SDavid Howells 	}
8544343d008SDavid Howells 
85513524ab3SDavid Howells 	trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
85613524ab3SDavid Howells 			     page->index, priv);
8574343d008SDavid Howells 	set_page_private(page, 0);
8584343d008SDavid Howells 	ClearPagePrivate(page);
8594343d008SDavid Howells 
8604343d008SDavid Howells #ifdef CONFIG_AFS_FSCACHE
8614343d008SDavid Howells 	if (PageFsCache(page)) {
8624343d008SDavid Howells 		fscache_wait_on_page_write(vnode->cache, page);
8634343d008SDavid Howells 		fscache_uncache_page(vnode->cache, page);
8644343d008SDavid Howells 	}
8654343d008SDavid Howells #endif
8664343d008SDavid Howells 	return ret;
86731143d5dSDavid Howells }
868