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 */ 114af3c9ccSAlexey Dobriyan #include <linux/backing-dev.h> 1231143d5dSDavid Howells #include <linux/slab.h> 1331143d5dSDavid Howells #include <linux/fs.h> 1431143d5dSDavid Howells #include <linux/pagemap.h> 1531143d5dSDavid Howells #include <linux/writeback.h> 1631143d5dSDavid Howells #include <linux/pagevec.h> 1731143d5dSDavid Howells #include "internal.h" 1831143d5dSDavid Howells 1931143d5dSDavid Howells static int afs_write_back_from_locked_page(struct afs_writeback *wb, 2031143d5dSDavid Howells struct page *page); 2131143d5dSDavid Howells 2231143d5dSDavid Howells /* 2331143d5dSDavid Howells * mark a page as having been made dirty and thus needing writeback 2431143d5dSDavid Howells */ 2531143d5dSDavid Howells int afs_set_page_dirty(struct page *page) 2631143d5dSDavid Howells { 2731143d5dSDavid Howells _enter(""); 2831143d5dSDavid Howells return __set_page_dirty_nobuffers(page); 2931143d5dSDavid Howells } 3031143d5dSDavid Howells 3131143d5dSDavid Howells /* 3231143d5dSDavid Howells * unlink a writeback record because its usage has reached zero 3331143d5dSDavid Howells * - must be called with the wb->vnode->writeback_lock held 3431143d5dSDavid Howells */ 3531143d5dSDavid Howells static void afs_unlink_writeback(struct afs_writeback *wb) 3631143d5dSDavid Howells { 3731143d5dSDavid Howells struct afs_writeback *front; 3831143d5dSDavid Howells struct afs_vnode *vnode = wb->vnode; 3931143d5dSDavid Howells 4031143d5dSDavid Howells list_del_init(&wb->link); 4131143d5dSDavid Howells if (!list_empty(&vnode->writebacks)) { 4231143d5dSDavid Howells /* if an fsync rises to the front of the queue then wake it 4331143d5dSDavid Howells * up */ 4431143d5dSDavid Howells front = list_entry(vnode->writebacks.next, 4531143d5dSDavid Howells struct afs_writeback, link); 4631143d5dSDavid Howells if (front->state == AFS_WBACK_SYNCING) { 4731143d5dSDavid Howells _debug("wake up sync"); 4831143d5dSDavid Howells front->state = AFS_WBACK_COMPLETE; 4931143d5dSDavid Howells wake_up(&front->waitq); 5031143d5dSDavid Howells } 5131143d5dSDavid Howells } 5231143d5dSDavid Howells } 5331143d5dSDavid Howells 5431143d5dSDavid Howells /* 5531143d5dSDavid Howells * free a writeback record 5631143d5dSDavid Howells */ 5731143d5dSDavid Howells static void afs_free_writeback(struct afs_writeback *wb) 5831143d5dSDavid Howells { 5931143d5dSDavid Howells _enter(""); 6031143d5dSDavid Howells key_put(wb->key); 6131143d5dSDavid Howells kfree(wb); 6231143d5dSDavid Howells } 6331143d5dSDavid Howells 6431143d5dSDavid Howells /* 6531143d5dSDavid Howells * dispose of a reference to a writeback record 6631143d5dSDavid Howells */ 6731143d5dSDavid Howells void afs_put_writeback(struct afs_writeback *wb) 6831143d5dSDavid Howells { 6931143d5dSDavid Howells struct afs_vnode *vnode = wb->vnode; 7031143d5dSDavid Howells 7131143d5dSDavid Howells _enter("{%d}", wb->usage); 7231143d5dSDavid Howells 7331143d5dSDavid Howells spin_lock(&vnode->writeback_lock); 7431143d5dSDavid Howells if (--wb->usage == 0) 7531143d5dSDavid Howells afs_unlink_writeback(wb); 7631143d5dSDavid Howells else 7731143d5dSDavid Howells wb = NULL; 7831143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 7931143d5dSDavid Howells if (wb) 8031143d5dSDavid Howells afs_free_writeback(wb); 8131143d5dSDavid Howells } 8231143d5dSDavid Howells 8331143d5dSDavid Howells /* 8431143d5dSDavid Howells * partly or wholly fill a page that's under preparation for writing 8531143d5dSDavid Howells */ 8631143d5dSDavid Howells static int afs_fill_page(struct afs_vnode *vnode, struct key *key, 8715b4650eSNick Piggin loff_t pos, unsigned len, struct page *page) 8831143d5dSDavid Howells { 8915b4650eSNick Piggin loff_t i_size; 9015b4650eSNick Piggin unsigned eof; 9131143d5dSDavid Howells int ret; 9231143d5dSDavid Howells 9315b4650eSNick Piggin _enter(",,%llu,%u", (unsigned long long)pos, len); 9431143d5dSDavid Howells 9515b4650eSNick Piggin ASSERTCMP(len, <=, PAGE_CACHE_SIZE); 9631143d5dSDavid Howells 9715b4650eSNick Piggin i_size = i_size_read(&vnode->vfs_inode); 9815b4650eSNick Piggin if (pos + len > i_size) 9915b4650eSNick Piggin eof = i_size; 10015b4650eSNick Piggin else 10115b4650eSNick Piggin eof = PAGE_CACHE_SIZE; 10215b4650eSNick Piggin 10315b4650eSNick Piggin ret = afs_vnode_fetch_data(vnode, key, 0, eof, page); 10431143d5dSDavid Howells if (ret < 0) { 10531143d5dSDavid Howells if (ret == -ENOENT) { 10631143d5dSDavid Howells _debug("got NOENT from server" 10731143d5dSDavid Howells " - marking file deleted and stale"); 10831143d5dSDavid Howells set_bit(AFS_VNODE_DELETED, &vnode->flags); 10931143d5dSDavid Howells ret = -ESTALE; 11031143d5dSDavid Howells } 11131143d5dSDavid Howells } 11231143d5dSDavid Howells 11331143d5dSDavid Howells _leave(" = %d", ret); 11431143d5dSDavid Howells return ret; 11531143d5dSDavid Howells } 11631143d5dSDavid Howells 11731143d5dSDavid Howells /* 11831143d5dSDavid Howells * prepare to perform part of a write to a page 11931143d5dSDavid Howells */ 12015b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping, 12115b4650eSNick Piggin loff_t pos, unsigned len, unsigned flags, 12215b4650eSNick Piggin struct page **pagep, void **fsdata) 12331143d5dSDavid Howells { 12431143d5dSDavid Howells struct afs_writeback *candidate, *wb; 12531143d5dSDavid Howells struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); 12615b4650eSNick Piggin struct page *page; 12731143d5dSDavid Howells struct key *key = file->private_data; 12815b4650eSNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 12915b4650eSNick Piggin unsigned to = from + len; 13015b4650eSNick Piggin pgoff_t index = pos >> PAGE_CACHE_SHIFT; 13131143d5dSDavid Howells int ret; 13231143d5dSDavid Howells 13331143d5dSDavid Howells _enter("{%x:%u},{%lx},%u,%u", 13415b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, index, from, to); 13531143d5dSDavid Howells 13631143d5dSDavid Howells candidate = kzalloc(sizeof(*candidate), GFP_KERNEL); 13731143d5dSDavid Howells if (!candidate) 13831143d5dSDavid Howells return -ENOMEM; 13931143d5dSDavid Howells candidate->vnode = vnode; 14015b4650eSNick Piggin candidate->first = candidate->last = index; 14115b4650eSNick Piggin candidate->offset_first = from; 14231143d5dSDavid Howells candidate->to_last = to; 14331143d5dSDavid Howells candidate->usage = 1; 14431143d5dSDavid Howells candidate->state = AFS_WBACK_PENDING; 14531143d5dSDavid Howells init_waitqueue_head(&candidate->waitq); 14631143d5dSDavid Howells 14754566b2cSNick Piggin page = grab_cache_page_write_begin(mapping, index, flags); 14815b4650eSNick Piggin if (!page) { 14915b4650eSNick Piggin kfree(candidate); 15015b4650eSNick Piggin return -ENOMEM; 15115b4650eSNick Piggin } 15215b4650eSNick Piggin *pagep = page; 15315b4650eSNick Piggin /* page won't leak in error case: it eventually gets cleaned off LRU */ 15415b4650eSNick Piggin 15531143d5dSDavid Howells if (!PageUptodate(page)) { 15631143d5dSDavid Howells _debug("not up to date"); 15715b4650eSNick Piggin ret = afs_fill_page(vnode, key, pos, len, page); 15831143d5dSDavid Howells if (ret < 0) { 15931143d5dSDavid Howells kfree(candidate); 16031143d5dSDavid Howells _leave(" = %d [prep]", ret); 16131143d5dSDavid Howells return ret; 16231143d5dSDavid Howells } 16315b4650eSNick Piggin SetPageUptodate(page); 16431143d5dSDavid Howells } 16531143d5dSDavid Howells 16631143d5dSDavid Howells try_again: 16731143d5dSDavid Howells spin_lock(&vnode->writeback_lock); 16831143d5dSDavid Howells 16931143d5dSDavid Howells /* see if this page is already pending a writeback under a suitable key 17031143d5dSDavid Howells * - if so we can just join onto that one */ 17131143d5dSDavid Howells wb = (struct afs_writeback *) page_private(page); 17231143d5dSDavid Howells if (wb) { 17331143d5dSDavid Howells if (wb->key == key && wb->state == AFS_WBACK_PENDING) 17431143d5dSDavid Howells goto subsume_in_current_wb; 17531143d5dSDavid Howells goto flush_conflicting_wb; 17631143d5dSDavid Howells } 17731143d5dSDavid Howells 17831143d5dSDavid Howells if (index > 0) { 17931143d5dSDavid Howells /* see if we can find an already pending writeback that we can 18031143d5dSDavid Howells * append this page to */ 18131143d5dSDavid Howells list_for_each_entry(wb, &vnode->writebacks, link) { 18231143d5dSDavid Howells if (wb->last == index - 1 && wb->key == key && 18331143d5dSDavid Howells wb->state == AFS_WBACK_PENDING) 18431143d5dSDavid Howells goto append_to_previous_wb; 18531143d5dSDavid Howells } 18631143d5dSDavid Howells } 18731143d5dSDavid Howells 18831143d5dSDavid Howells list_add_tail(&candidate->link, &vnode->writebacks); 18931143d5dSDavid Howells candidate->key = key_get(key); 19031143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 19131143d5dSDavid Howells SetPagePrivate(page); 19231143d5dSDavid Howells set_page_private(page, (unsigned long) candidate); 19331143d5dSDavid Howells _leave(" = 0 [new]"); 19431143d5dSDavid Howells return 0; 19531143d5dSDavid Howells 19631143d5dSDavid Howells subsume_in_current_wb: 19731143d5dSDavid Howells _debug("subsume"); 19831143d5dSDavid Howells ASSERTRANGE(wb->first, <=, index, <=, wb->last); 19915b4650eSNick Piggin if (index == wb->first && from < wb->offset_first) 20015b4650eSNick Piggin wb->offset_first = from; 20131143d5dSDavid Howells if (index == wb->last && to > wb->to_last) 20231143d5dSDavid Howells wb->to_last = to; 20331143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 20431143d5dSDavid Howells kfree(candidate); 20531143d5dSDavid Howells _leave(" = 0 [sub]"); 20631143d5dSDavid Howells return 0; 20731143d5dSDavid Howells 20831143d5dSDavid Howells append_to_previous_wb: 20931143d5dSDavid Howells _debug("append into %lx-%lx", wb->first, wb->last); 21031143d5dSDavid Howells wb->usage++; 21131143d5dSDavid Howells wb->last++; 21231143d5dSDavid Howells wb->to_last = to; 21331143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 21431143d5dSDavid Howells SetPagePrivate(page); 21531143d5dSDavid Howells set_page_private(page, (unsigned long) wb); 21631143d5dSDavid Howells kfree(candidate); 21731143d5dSDavid Howells _leave(" = 0 [app]"); 21831143d5dSDavid Howells return 0; 21931143d5dSDavid Howells 22031143d5dSDavid Howells /* the page is currently bound to another context, so if it's dirty we 22131143d5dSDavid Howells * need to flush it before we can use the new context */ 22231143d5dSDavid Howells flush_conflicting_wb: 22331143d5dSDavid Howells _debug("flush conflict"); 22431143d5dSDavid Howells if (wb->state == AFS_WBACK_PENDING) 22531143d5dSDavid Howells wb->state = AFS_WBACK_CONFLICTING; 22631143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 22731143d5dSDavid Howells if (PageDirty(page)) { 22831143d5dSDavid Howells ret = afs_write_back_from_locked_page(wb, page); 22931143d5dSDavid Howells if (ret < 0) { 23031143d5dSDavid Howells afs_put_writeback(candidate); 23131143d5dSDavid Howells _leave(" = %d", ret); 23231143d5dSDavid Howells return ret; 23331143d5dSDavid Howells } 23431143d5dSDavid Howells } 23531143d5dSDavid Howells 23631143d5dSDavid Howells /* the page holds a ref on the writeback record */ 23731143d5dSDavid Howells afs_put_writeback(wb); 23831143d5dSDavid Howells set_page_private(page, 0); 23931143d5dSDavid Howells ClearPagePrivate(page); 24031143d5dSDavid Howells goto try_again; 24131143d5dSDavid Howells } 24231143d5dSDavid Howells 24331143d5dSDavid Howells /* 24431143d5dSDavid Howells * finalise part of a write to a page 24531143d5dSDavid Howells */ 24615b4650eSNick Piggin int afs_write_end(struct file *file, struct address_space *mapping, 24715b4650eSNick Piggin loff_t pos, unsigned len, unsigned copied, 24815b4650eSNick Piggin struct page *page, void *fsdata) 24931143d5dSDavid Howells { 25031143d5dSDavid Howells struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); 25131143d5dSDavid Howells loff_t i_size, maybe_i_size; 25231143d5dSDavid Howells 25315b4650eSNick Piggin _enter("{%x:%u},{%lx}", 25415b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, page->index); 25531143d5dSDavid Howells 25615b4650eSNick Piggin maybe_i_size = pos + copied; 25731143d5dSDavid Howells 25831143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 25931143d5dSDavid Howells if (maybe_i_size > i_size) { 26031143d5dSDavid Howells spin_lock(&vnode->writeback_lock); 26131143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 26231143d5dSDavid Howells if (maybe_i_size > i_size) 26331143d5dSDavid Howells i_size_write(&vnode->vfs_inode, maybe_i_size); 26431143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 26531143d5dSDavid Howells } 26631143d5dSDavid Howells 26731143d5dSDavid Howells set_page_dirty(page); 26831143d5dSDavid Howells if (PageDirty(page)) 26931143d5dSDavid Howells _debug("dirtied"); 27015b4650eSNick Piggin unlock_page(page); 27115b4650eSNick Piggin page_cache_release(page); 27231143d5dSDavid Howells 27315b4650eSNick Piggin return copied; 27431143d5dSDavid Howells } 27531143d5dSDavid Howells 27631143d5dSDavid Howells /* 27731143d5dSDavid Howells * kill all the pages in the given range 27831143d5dSDavid Howells */ 27931143d5dSDavid Howells static void afs_kill_pages(struct afs_vnode *vnode, bool error, 28031143d5dSDavid Howells pgoff_t first, pgoff_t last) 28131143d5dSDavid Howells { 28231143d5dSDavid Howells struct pagevec pv; 28331143d5dSDavid Howells unsigned count, loop; 28431143d5dSDavid Howells 28531143d5dSDavid Howells _enter("{%x:%u},%lx-%lx", 28631143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 28731143d5dSDavid Howells 28831143d5dSDavid Howells pagevec_init(&pv, 0); 28931143d5dSDavid Howells 29031143d5dSDavid Howells do { 29131143d5dSDavid Howells _debug("kill %lx-%lx", first, last); 29231143d5dSDavid Howells 29331143d5dSDavid Howells count = last - first + 1; 29431143d5dSDavid Howells if (count > PAGEVEC_SIZE) 29531143d5dSDavid Howells count = PAGEVEC_SIZE; 29631143d5dSDavid Howells pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, 29731143d5dSDavid Howells first, count, pv.pages); 29831143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 29931143d5dSDavid Howells 30031143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 30131143d5dSDavid Howells ClearPageUptodate(pv.pages[loop]); 30231143d5dSDavid Howells if (error) 30331143d5dSDavid Howells SetPageError(pv.pages[loop]); 30431143d5dSDavid Howells end_page_writeback(pv.pages[loop]); 30531143d5dSDavid Howells } 30631143d5dSDavid Howells 30731143d5dSDavid Howells __pagevec_release(&pv); 30831143d5dSDavid Howells } while (first < last); 30931143d5dSDavid Howells 31031143d5dSDavid Howells _leave(""); 31131143d5dSDavid Howells } 31231143d5dSDavid Howells 31331143d5dSDavid Howells /* 31431143d5dSDavid Howells * synchronously write back the locked page and any subsequent non-locked dirty 31531143d5dSDavid Howells * pages also covered by the same writeback record 31631143d5dSDavid Howells */ 31731143d5dSDavid Howells static int afs_write_back_from_locked_page(struct afs_writeback *wb, 31831143d5dSDavid Howells struct page *primary_page) 31931143d5dSDavid Howells { 32031143d5dSDavid Howells struct page *pages[8], *page; 32131143d5dSDavid Howells unsigned long count; 32231143d5dSDavid Howells unsigned n, offset, to; 32331143d5dSDavid Howells pgoff_t start, first, last; 32431143d5dSDavid Howells int loop, ret; 32531143d5dSDavid Howells 32631143d5dSDavid Howells _enter(",%lx", primary_page->index); 32731143d5dSDavid Howells 32831143d5dSDavid Howells count = 1; 32931143d5dSDavid Howells if (!clear_page_dirty_for_io(primary_page)) 33031143d5dSDavid Howells BUG(); 33131143d5dSDavid Howells if (test_set_page_writeback(primary_page)) 33231143d5dSDavid Howells BUG(); 33331143d5dSDavid Howells 33431143d5dSDavid Howells /* find all consecutive lockable dirty pages, stopping when we find a 33531143d5dSDavid Howells * page that is not immediately lockable, is not dirty or is missing, 33631143d5dSDavid Howells * or we reach the end of the range */ 33731143d5dSDavid Howells start = primary_page->index; 33831143d5dSDavid Howells if (start >= wb->last) 33931143d5dSDavid Howells goto no_more; 34031143d5dSDavid Howells start++; 34131143d5dSDavid Howells do { 34231143d5dSDavid Howells _debug("more %lx [%lx]", start, count); 34331143d5dSDavid Howells n = wb->last - start + 1; 34431143d5dSDavid Howells if (n > ARRAY_SIZE(pages)) 34531143d5dSDavid Howells n = ARRAY_SIZE(pages); 34631143d5dSDavid Howells n = find_get_pages_contig(wb->vnode->vfs_inode.i_mapping, 34731143d5dSDavid Howells start, n, pages); 34831143d5dSDavid Howells _debug("fgpc %u", n); 34931143d5dSDavid Howells if (n == 0) 35031143d5dSDavid Howells goto no_more; 35131143d5dSDavid Howells if (pages[0]->index != start) { 3529d577b6aSDavid Howells do { 3539d577b6aSDavid Howells put_page(pages[--n]); 3549d577b6aSDavid Howells } while (n > 0); 35531143d5dSDavid Howells goto no_more; 35631143d5dSDavid Howells } 35731143d5dSDavid Howells 35831143d5dSDavid Howells for (loop = 0; loop < n; loop++) { 35931143d5dSDavid Howells page = pages[loop]; 36031143d5dSDavid Howells if (page->index > wb->last) 36131143d5dSDavid Howells break; 362529ae9aaSNick Piggin if (!trylock_page(page)) 36331143d5dSDavid Howells break; 36431143d5dSDavid Howells if (!PageDirty(page) || 36531143d5dSDavid Howells page_private(page) != (unsigned long) wb) { 36631143d5dSDavid Howells unlock_page(page); 36731143d5dSDavid Howells break; 36831143d5dSDavid Howells } 36931143d5dSDavid Howells if (!clear_page_dirty_for_io(page)) 37031143d5dSDavid Howells BUG(); 37131143d5dSDavid Howells if (test_set_page_writeback(page)) 37231143d5dSDavid Howells BUG(); 37331143d5dSDavid Howells unlock_page(page); 37431143d5dSDavid Howells put_page(page); 37531143d5dSDavid Howells } 37631143d5dSDavid Howells count += loop; 37731143d5dSDavid Howells if (loop < n) { 37831143d5dSDavid Howells for (; loop < n; loop++) 37931143d5dSDavid Howells put_page(pages[loop]); 38031143d5dSDavid Howells goto no_more; 38131143d5dSDavid Howells } 38231143d5dSDavid Howells 38331143d5dSDavid Howells start += loop; 38431143d5dSDavid Howells } while (start <= wb->last && count < 65536); 38531143d5dSDavid Howells 38631143d5dSDavid Howells no_more: 38731143d5dSDavid Howells /* we now have a contiguous set of dirty pages, each with writeback set 38831143d5dSDavid Howells * and the dirty mark cleared; the first page is locked and must remain 38931143d5dSDavid Howells * so, all the rest are unlocked */ 39031143d5dSDavid Howells first = primary_page->index; 39131143d5dSDavid Howells last = first + count - 1; 39231143d5dSDavid Howells 39331143d5dSDavid Howells offset = (first == wb->first) ? wb->offset_first : 0; 39431143d5dSDavid Howells to = (last == wb->last) ? wb->to_last : PAGE_SIZE; 39531143d5dSDavid Howells 39631143d5dSDavid Howells _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); 39731143d5dSDavid Howells 39831143d5dSDavid Howells ret = afs_vnode_store_data(wb, first, last, offset, to); 39931143d5dSDavid Howells if (ret < 0) { 40031143d5dSDavid Howells switch (ret) { 40131143d5dSDavid Howells case -EDQUOT: 40231143d5dSDavid Howells case -ENOSPC: 40331143d5dSDavid Howells set_bit(AS_ENOSPC, 40431143d5dSDavid Howells &wb->vnode->vfs_inode.i_mapping->flags); 40531143d5dSDavid Howells break; 40631143d5dSDavid Howells case -EROFS: 40731143d5dSDavid Howells case -EIO: 40831143d5dSDavid Howells case -EREMOTEIO: 40931143d5dSDavid Howells case -EFBIG: 41031143d5dSDavid Howells case -ENOENT: 41131143d5dSDavid Howells case -ENOMEDIUM: 41231143d5dSDavid Howells case -ENXIO: 41331143d5dSDavid Howells afs_kill_pages(wb->vnode, true, first, last); 41431143d5dSDavid Howells set_bit(AS_EIO, &wb->vnode->vfs_inode.i_mapping->flags); 41531143d5dSDavid Howells break; 41631143d5dSDavid Howells case -EACCES: 41731143d5dSDavid Howells case -EPERM: 41831143d5dSDavid Howells case -ENOKEY: 41931143d5dSDavid Howells case -EKEYEXPIRED: 42031143d5dSDavid Howells case -EKEYREJECTED: 42131143d5dSDavid Howells case -EKEYREVOKED: 42231143d5dSDavid Howells afs_kill_pages(wb->vnode, false, first, last); 42331143d5dSDavid Howells break; 42431143d5dSDavid Howells default: 42531143d5dSDavid Howells break; 42631143d5dSDavid Howells } 42731143d5dSDavid Howells } else { 42831143d5dSDavid Howells ret = count; 42931143d5dSDavid Howells } 43031143d5dSDavid Howells 43131143d5dSDavid Howells _leave(" = %d", ret); 43231143d5dSDavid Howells return ret; 43331143d5dSDavid Howells } 43431143d5dSDavid Howells 43531143d5dSDavid Howells /* 43631143d5dSDavid Howells * write a page back to the server 43731143d5dSDavid Howells * - the caller locked the page for us 43831143d5dSDavid Howells */ 43931143d5dSDavid Howells int afs_writepage(struct page *page, struct writeback_control *wbc) 44031143d5dSDavid Howells { 44131143d5dSDavid Howells struct backing_dev_info *bdi = page->mapping->backing_dev_info; 44231143d5dSDavid Howells struct afs_writeback *wb; 44331143d5dSDavid Howells int ret; 44431143d5dSDavid Howells 44531143d5dSDavid Howells _enter("{%lx},", page->index); 44631143d5dSDavid Howells 44731143d5dSDavid Howells wb = (struct afs_writeback *) page_private(page); 44831143d5dSDavid Howells ASSERT(wb != NULL); 44931143d5dSDavid Howells 45031143d5dSDavid Howells ret = afs_write_back_from_locked_page(wb, page); 45131143d5dSDavid Howells unlock_page(page); 45231143d5dSDavid Howells if (ret < 0) { 45331143d5dSDavid Howells _leave(" = %d", ret); 45431143d5dSDavid Howells return 0; 45531143d5dSDavid Howells } 45631143d5dSDavid Howells 45731143d5dSDavid Howells wbc->nr_to_write -= ret; 45831143d5dSDavid Howells if (wbc->nonblocking && bdi_write_congested(bdi)) 45931143d5dSDavid Howells wbc->encountered_congestion = 1; 46031143d5dSDavid Howells 46131143d5dSDavid Howells _leave(" = 0"); 46231143d5dSDavid Howells return 0; 46331143d5dSDavid Howells } 46431143d5dSDavid Howells 46531143d5dSDavid Howells /* 46631143d5dSDavid Howells * write a region of pages back to the server 46731143d5dSDavid Howells */ 468c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping, 46931143d5dSDavid Howells struct writeback_control *wbc, 47031143d5dSDavid Howells pgoff_t index, pgoff_t end, pgoff_t *_next) 47131143d5dSDavid Howells { 47231143d5dSDavid Howells struct backing_dev_info *bdi = mapping->backing_dev_info; 47331143d5dSDavid Howells struct afs_writeback *wb; 47431143d5dSDavid Howells struct page *page; 47531143d5dSDavid Howells int ret, n; 47631143d5dSDavid Howells 47731143d5dSDavid Howells _enter(",,%lx,%lx,", index, end); 47831143d5dSDavid Howells 47931143d5dSDavid Howells do { 48031143d5dSDavid Howells n = find_get_pages_tag(mapping, &index, PAGECACHE_TAG_DIRTY, 48131143d5dSDavid Howells 1, &page); 48231143d5dSDavid Howells if (!n) 48331143d5dSDavid Howells break; 48431143d5dSDavid Howells 48531143d5dSDavid Howells _debug("wback %lx", page->index); 48631143d5dSDavid Howells 48731143d5dSDavid Howells if (page->index > end) { 48831143d5dSDavid Howells *_next = index; 48931143d5dSDavid Howells page_cache_release(page); 49031143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 49131143d5dSDavid Howells return 0; 49231143d5dSDavid Howells } 49331143d5dSDavid Howells 49431143d5dSDavid Howells /* at this point we hold neither mapping->tree_lock nor lock on 49531143d5dSDavid Howells * the page itself: the page may be truncated or invalidated 49631143d5dSDavid Howells * (changing page->mapping to NULL), or even swizzled back from 49731143d5dSDavid Howells * swapper_space to tmpfs file mapping 49831143d5dSDavid Howells */ 49931143d5dSDavid Howells lock_page(page); 50031143d5dSDavid Howells 50131143d5dSDavid Howells if (page->mapping != mapping) { 50231143d5dSDavid Howells unlock_page(page); 50331143d5dSDavid Howells page_cache_release(page); 50431143d5dSDavid Howells continue; 50531143d5dSDavid Howells } 50631143d5dSDavid Howells 50731143d5dSDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) 50831143d5dSDavid Howells wait_on_page_writeback(page); 50931143d5dSDavid Howells 51031143d5dSDavid Howells if (PageWriteback(page) || !PageDirty(page)) { 51131143d5dSDavid Howells unlock_page(page); 51231143d5dSDavid Howells continue; 51331143d5dSDavid Howells } 51431143d5dSDavid Howells 51531143d5dSDavid Howells wb = (struct afs_writeback *) page_private(page); 51631143d5dSDavid Howells ASSERT(wb != NULL); 51731143d5dSDavid Howells 51831143d5dSDavid Howells spin_lock(&wb->vnode->writeback_lock); 51931143d5dSDavid Howells wb->state = AFS_WBACK_WRITING; 52031143d5dSDavid Howells spin_unlock(&wb->vnode->writeback_lock); 52131143d5dSDavid Howells 52231143d5dSDavid Howells ret = afs_write_back_from_locked_page(wb, page); 52331143d5dSDavid Howells unlock_page(page); 52431143d5dSDavid Howells page_cache_release(page); 52531143d5dSDavid Howells if (ret < 0) { 52631143d5dSDavid Howells _leave(" = %d", ret); 52731143d5dSDavid Howells return ret; 52831143d5dSDavid Howells } 52931143d5dSDavid Howells 53031143d5dSDavid Howells wbc->nr_to_write -= ret; 53131143d5dSDavid Howells 53231143d5dSDavid Howells if (wbc->nonblocking && bdi_write_congested(bdi)) { 53331143d5dSDavid Howells wbc->encountered_congestion = 1; 53431143d5dSDavid Howells break; 53531143d5dSDavid Howells } 53631143d5dSDavid Howells 53731143d5dSDavid Howells cond_resched(); 53831143d5dSDavid Howells } while (index < end && wbc->nr_to_write > 0); 53931143d5dSDavid Howells 54031143d5dSDavid Howells *_next = index; 54131143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 54231143d5dSDavid Howells return 0; 54331143d5dSDavid Howells } 54431143d5dSDavid Howells 54531143d5dSDavid Howells /* 54631143d5dSDavid Howells * write some of the pending data back to the server 54731143d5dSDavid Howells */ 54831143d5dSDavid Howells int afs_writepages(struct address_space *mapping, 54931143d5dSDavid Howells struct writeback_control *wbc) 55031143d5dSDavid Howells { 55131143d5dSDavid Howells struct backing_dev_info *bdi = mapping->backing_dev_info; 55231143d5dSDavid Howells pgoff_t start, end, next; 55331143d5dSDavid Howells int ret; 55431143d5dSDavid Howells 55531143d5dSDavid Howells _enter(""); 55631143d5dSDavid Howells 55731143d5dSDavid Howells if (wbc->nonblocking && bdi_write_congested(bdi)) { 55831143d5dSDavid Howells wbc->encountered_congestion = 1; 55931143d5dSDavid Howells _leave(" = 0 [congest]"); 56031143d5dSDavid Howells return 0; 56131143d5dSDavid Howells } 56231143d5dSDavid Howells 56331143d5dSDavid Howells if (wbc->range_cyclic) { 56431143d5dSDavid Howells start = mapping->writeback_index; 56531143d5dSDavid Howells end = -1; 56631143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 56731143d5dSDavid Howells if (start > 0 && wbc->nr_to_write > 0 && ret == 0 && 56831143d5dSDavid Howells !(wbc->nonblocking && wbc->encountered_congestion)) 56931143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, start, 57031143d5dSDavid Howells &next); 57131143d5dSDavid Howells mapping->writeback_index = next; 57231143d5dSDavid Howells } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { 57331143d5dSDavid Howells end = (pgoff_t)(LLONG_MAX >> PAGE_CACHE_SHIFT); 57431143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, end, &next); 57531143d5dSDavid Howells if (wbc->nr_to_write > 0) 57631143d5dSDavid Howells mapping->writeback_index = next; 57731143d5dSDavid Howells } else { 57831143d5dSDavid Howells start = wbc->range_start >> PAGE_CACHE_SHIFT; 57931143d5dSDavid Howells end = wbc->range_end >> PAGE_CACHE_SHIFT; 58031143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 58131143d5dSDavid Howells } 58231143d5dSDavid Howells 58331143d5dSDavid Howells _leave(" = %d", ret); 58431143d5dSDavid Howells return ret; 58531143d5dSDavid Howells } 58631143d5dSDavid Howells 58731143d5dSDavid Howells /* 58831143d5dSDavid Howells * completion of write to server 58931143d5dSDavid Howells */ 59031143d5dSDavid Howells void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call) 59131143d5dSDavid Howells { 59231143d5dSDavid Howells struct afs_writeback *wb = call->wb; 59331143d5dSDavid Howells struct pagevec pv; 59431143d5dSDavid Howells unsigned count, loop; 59531143d5dSDavid Howells pgoff_t first = call->first, last = call->last; 59631143d5dSDavid Howells bool free_wb; 59731143d5dSDavid Howells 59831143d5dSDavid Howells _enter("{%x:%u},{%lx-%lx}", 59931143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 60031143d5dSDavid Howells 60131143d5dSDavid Howells ASSERT(wb != NULL); 60231143d5dSDavid Howells 60331143d5dSDavid Howells pagevec_init(&pv, 0); 60431143d5dSDavid Howells 60531143d5dSDavid Howells do { 6065bbf5d39SDavid Howells _debug("done %lx-%lx", first, last); 60731143d5dSDavid Howells 60831143d5dSDavid Howells count = last - first + 1; 60931143d5dSDavid Howells if (count > PAGEVEC_SIZE) 61031143d5dSDavid Howells count = PAGEVEC_SIZE; 61131143d5dSDavid Howells pv.nr = find_get_pages_contig(call->mapping, first, count, 61231143d5dSDavid Howells pv.pages); 61331143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 61431143d5dSDavid Howells 61531143d5dSDavid Howells spin_lock(&vnode->writeback_lock); 61631143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 61731143d5dSDavid Howells struct page *page = pv.pages[loop]; 61831143d5dSDavid Howells end_page_writeback(page); 61931143d5dSDavid Howells if (page_private(page) == (unsigned long) wb) { 62031143d5dSDavid Howells set_page_private(page, 0); 62131143d5dSDavid Howells ClearPagePrivate(page); 62231143d5dSDavid Howells wb->usage--; 62331143d5dSDavid Howells } 62431143d5dSDavid Howells } 62531143d5dSDavid Howells free_wb = false; 62631143d5dSDavid Howells if (wb->usage == 0) { 62731143d5dSDavid Howells afs_unlink_writeback(wb); 62831143d5dSDavid Howells free_wb = true; 62931143d5dSDavid Howells } 63031143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 63131143d5dSDavid Howells first += count; 63231143d5dSDavid Howells if (free_wb) { 63331143d5dSDavid Howells afs_free_writeback(wb); 63431143d5dSDavid Howells wb = NULL; 63531143d5dSDavid Howells } 63631143d5dSDavid Howells 63731143d5dSDavid Howells __pagevec_release(&pv); 6385bbf5d39SDavid Howells } while (first <= last); 63931143d5dSDavid Howells 64031143d5dSDavid Howells _leave(""); 64131143d5dSDavid Howells } 64231143d5dSDavid Howells 64331143d5dSDavid Howells /* 64431143d5dSDavid Howells * write to an AFS file 64531143d5dSDavid Howells */ 64631143d5dSDavid Howells ssize_t afs_file_write(struct kiocb *iocb, const struct iovec *iov, 64731143d5dSDavid Howells unsigned long nr_segs, loff_t pos) 64831143d5dSDavid Howells { 64931143d5dSDavid Howells struct dentry *dentry = iocb->ki_filp->f_path.dentry; 65031143d5dSDavid Howells struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 65131143d5dSDavid Howells ssize_t result; 65231143d5dSDavid Howells size_t count = iov_length(iov, nr_segs); 65331143d5dSDavid Howells 65431143d5dSDavid Howells _enter("{%x.%u},{%zu},%lu,", 65531143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, count, nr_segs); 65631143d5dSDavid Howells 65731143d5dSDavid Howells if (IS_SWAPFILE(&vnode->vfs_inode)) { 65831143d5dSDavid Howells printk(KERN_INFO 65931143d5dSDavid Howells "AFS: Attempt to write to active swap file!\n"); 66031143d5dSDavid Howells return -EBUSY; 66131143d5dSDavid Howells } 66231143d5dSDavid Howells 66331143d5dSDavid Howells if (!count) 66431143d5dSDavid Howells return 0; 66531143d5dSDavid Howells 66631143d5dSDavid Howells result = generic_file_aio_write(iocb, iov, nr_segs, pos); 66731143d5dSDavid Howells if (IS_ERR_VALUE(result)) { 66831143d5dSDavid Howells _leave(" = %zd", result); 66931143d5dSDavid Howells return result; 67031143d5dSDavid Howells } 67131143d5dSDavid Howells 67231143d5dSDavid Howells _leave(" = %zd", result); 67331143d5dSDavid Howells return result; 67431143d5dSDavid Howells } 67531143d5dSDavid Howells 67631143d5dSDavid Howells /* 67731143d5dSDavid Howells * flush the vnode to the fileserver 67831143d5dSDavid Howells */ 67931143d5dSDavid Howells int afs_writeback_all(struct afs_vnode *vnode) 68031143d5dSDavid Howells { 68131143d5dSDavid Howells struct address_space *mapping = vnode->vfs_inode.i_mapping; 68231143d5dSDavid Howells struct writeback_control wbc = { 68331143d5dSDavid Howells .bdi = mapping->backing_dev_info, 68431143d5dSDavid Howells .sync_mode = WB_SYNC_ALL, 68531143d5dSDavid Howells .nr_to_write = LONG_MAX, 68631143d5dSDavid Howells .range_cyclic = 1, 68731143d5dSDavid Howells }; 68831143d5dSDavid Howells int ret; 68931143d5dSDavid Howells 69031143d5dSDavid Howells _enter(""); 69131143d5dSDavid Howells 69231143d5dSDavid Howells ret = mapping->a_ops->writepages(mapping, &wbc); 69331143d5dSDavid Howells __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); 69431143d5dSDavid Howells 69531143d5dSDavid Howells _leave(" = %d", ret); 69631143d5dSDavid Howells return ret; 69731143d5dSDavid Howells } 69831143d5dSDavid Howells 69931143d5dSDavid Howells /* 70031143d5dSDavid Howells * flush any dirty pages for this process, and check for write errors. 70131143d5dSDavid Howells * - the return status from this call provides a reliable indication of 70231143d5dSDavid Howells * whether any write errors occurred for this process. 70331143d5dSDavid Howells */ 7047ea80859SChristoph Hellwig int afs_fsync(struct file *file, int datasync) 70531143d5dSDavid Howells { 7067ea80859SChristoph Hellwig struct dentry *dentry = file->f_path.dentry; 70731143d5dSDavid Howells struct afs_writeback *wb, *xwb; 70831143d5dSDavid Howells struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 70931143d5dSDavid Howells int ret; 71031143d5dSDavid Howells 71131143d5dSDavid Howells _enter("{%x:%u},{n=%s},%d", 71231143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, 71331143d5dSDavid Howells datasync); 71431143d5dSDavid Howells 71531143d5dSDavid Howells /* use a writeback record as a marker in the queue - when this reaches 71631143d5dSDavid Howells * the front of the queue, all the outstanding writes are either 71731143d5dSDavid Howells * completed or rejected */ 71831143d5dSDavid Howells wb = kzalloc(sizeof(*wb), GFP_KERNEL); 71931143d5dSDavid Howells if (!wb) 72031143d5dSDavid Howells return -ENOMEM; 72131143d5dSDavid Howells wb->vnode = vnode; 72231143d5dSDavid Howells wb->first = 0; 72331143d5dSDavid Howells wb->last = -1; 72431143d5dSDavid Howells wb->offset_first = 0; 72531143d5dSDavid Howells wb->to_last = PAGE_SIZE; 72631143d5dSDavid Howells wb->usage = 1; 72731143d5dSDavid Howells wb->state = AFS_WBACK_SYNCING; 72831143d5dSDavid Howells init_waitqueue_head(&wb->waitq); 72931143d5dSDavid Howells 73031143d5dSDavid Howells spin_lock(&vnode->writeback_lock); 73131143d5dSDavid Howells list_for_each_entry(xwb, &vnode->writebacks, link) { 73231143d5dSDavid Howells if (xwb->state == AFS_WBACK_PENDING) 73331143d5dSDavid Howells xwb->state = AFS_WBACK_CONFLICTING; 73431143d5dSDavid Howells } 73531143d5dSDavid Howells list_add_tail(&wb->link, &vnode->writebacks); 73631143d5dSDavid Howells spin_unlock(&vnode->writeback_lock); 73731143d5dSDavid Howells 73831143d5dSDavid Howells /* push all the outstanding writebacks to the server */ 73931143d5dSDavid Howells ret = afs_writeback_all(vnode); 74031143d5dSDavid Howells if (ret < 0) { 74131143d5dSDavid Howells afs_put_writeback(wb); 74231143d5dSDavid Howells _leave(" = %d [wb]", ret); 74331143d5dSDavid Howells return ret; 74431143d5dSDavid Howells } 74531143d5dSDavid Howells 74631143d5dSDavid Howells /* wait for the preceding writes to actually complete */ 74731143d5dSDavid Howells ret = wait_event_interruptible(wb->waitq, 74831143d5dSDavid Howells wb->state == AFS_WBACK_COMPLETE || 74931143d5dSDavid Howells vnode->writebacks.next == &wb->link); 75031143d5dSDavid Howells afs_put_writeback(wb); 75131143d5dSDavid Howells _leave(" = %d", ret); 75231143d5dSDavid Howells return ret; 75331143d5dSDavid Howells } 7549b3f26c9SDavid Howells 7559b3f26c9SDavid Howells /* 7569b3f26c9SDavid Howells * notification that a previously read-only page is about to become writable 7579b3f26c9SDavid Howells * - if it returns an error, the caller will deliver a bus error signal 7589b3f26c9SDavid Howells */ 7599b3f26c9SDavid Howells int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page) 7609b3f26c9SDavid Howells { 7619b3f26c9SDavid Howells struct afs_vnode *vnode = AFS_FS_I(vma->vm_file->f_mapping->host); 7629b3f26c9SDavid Howells 7639b3f26c9SDavid Howells _enter("{{%x:%u}},{%lx}", 7649b3f26c9SDavid Howells vnode->fid.vid, vnode->fid.vnode, page->index); 7659b3f26c9SDavid Howells 7669b3f26c9SDavid Howells /* wait for the page to be written to the cache before we allow it to 7679b3f26c9SDavid Howells * be modified */ 7689b3f26c9SDavid Howells #ifdef CONFIG_AFS_FSCACHE 7699b3f26c9SDavid Howells fscache_wait_on_page_write(vnode->cache, page); 7709b3f26c9SDavid Howells #endif 7719b3f26c9SDavid Howells 7729b3f26c9SDavid Howells _leave(" = 0"); 7739b3f26c9SDavid Howells return 0; 7749b3f26c9SDavid Howells } 775