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 204343d008SDavid Howells /* 214343d008SDavid Howells * We use page->private to hold the amount of the page that we've written to, 224343d008SDavid Howells * splitting the field into two parts. However, we need to represent a range 234343d008SDavid Howells * 0...PAGE_SIZE inclusive, so we can't support 64K pages on a 32-bit system. 244343d008SDavid Howells */ 254343d008SDavid Howells #if PAGE_SIZE > 32768 264343d008SDavid Howells #define AFS_PRIV_MAX 0xffffffff 274343d008SDavid Howells #define AFS_PRIV_SHIFT 32 284343d008SDavid Howells #else 294343d008SDavid Howells #define AFS_PRIV_MAX 0xffff 304343d008SDavid Howells #define AFS_PRIV_SHIFT 16 314343d008SDavid Howells #endif 3231143d5dSDavid Howells 3331143d5dSDavid Howells /* 3431143d5dSDavid Howells * mark a page as having been made dirty and thus needing writeback 3531143d5dSDavid Howells */ 3631143d5dSDavid Howells int afs_set_page_dirty(struct page *page) 3731143d5dSDavid Howells { 3831143d5dSDavid Howells _enter(""); 3931143d5dSDavid Howells return __set_page_dirty_nobuffers(page); 4031143d5dSDavid Howells } 4131143d5dSDavid Howells 4231143d5dSDavid Howells /* 4331143d5dSDavid Howells * partly or wholly fill a page that's under preparation for writing 4431143d5dSDavid Howells */ 4531143d5dSDavid Howells static int afs_fill_page(struct afs_vnode *vnode, struct key *key, 46e8e581a8SDavid Howells loff_t pos, unsigned int len, struct page *page) 4731143d5dSDavid Howells { 48196ee9cdSDavid Howells struct afs_read *req; 4931143d5dSDavid Howells int ret; 5031143d5dSDavid Howells 515e7f2337SAnton Blanchard _enter(",,%llu", (unsigned long long)pos); 5231143d5dSDavid Howells 53196ee9cdSDavid Howells req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *), 54196ee9cdSDavid Howells GFP_KERNEL); 55196ee9cdSDavid Howells if (!req) 56196ee9cdSDavid Howells return -ENOMEM; 57196ee9cdSDavid Howells 58196ee9cdSDavid Howells atomic_set(&req->usage, 1); 59196ee9cdSDavid Howells req->pos = pos; 60e8e581a8SDavid Howells req->len = len; 61196ee9cdSDavid Howells req->nr_pages = 1; 62196ee9cdSDavid Howells req->pages[0] = page; 635611ef28SDavid Howells get_page(page); 64196ee9cdSDavid Howells 65d2ddc776SDavid Howells ret = afs_fetch_data(vnode, key, req); 66196ee9cdSDavid Howells afs_put_read(req); 6731143d5dSDavid Howells if (ret < 0) { 6831143d5dSDavid Howells if (ret == -ENOENT) { 6931143d5dSDavid Howells _debug("got NOENT from server" 7031143d5dSDavid Howells " - marking file deleted and stale"); 7131143d5dSDavid Howells set_bit(AFS_VNODE_DELETED, &vnode->flags); 7231143d5dSDavid Howells ret = -ESTALE; 7331143d5dSDavid Howells } 7431143d5dSDavid Howells } 7531143d5dSDavid Howells 7631143d5dSDavid Howells _leave(" = %d", ret); 7731143d5dSDavid Howells return ret; 7831143d5dSDavid Howells } 7931143d5dSDavid Howells 8031143d5dSDavid Howells /* 8131143d5dSDavid Howells * prepare to perform part of a write to a page 8231143d5dSDavid Howells */ 8315b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping, 8415b4650eSNick Piggin loff_t pos, unsigned len, unsigned flags, 8515b4650eSNick Piggin struct page **pagep, void **fsdata) 8631143d5dSDavid Howells { 87496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 8815b4650eSNick Piggin struct page *page; 89215804a9SDavid Howells struct key *key = afs_file_key(file); 904343d008SDavid Howells unsigned long priv; 914343d008SDavid Howells unsigned f, from = pos & (PAGE_SIZE - 1); 924343d008SDavid Howells unsigned t, to = from + len; 9309cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT; 9431143d5dSDavid Howells int ret; 9531143d5dSDavid Howells 9631143d5dSDavid Howells _enter("{%x:%u},{%lx},%u,%u", 9715b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, index, from, to); 9831143d5dSDavid Howells 994343d008SDavid Howells /* We want to store information about how much of a page is altered in 1004343d008SDavid Howells * page->private. 1014343d008SDavid Howells */ 1024343d008SDavid Howells BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8); 10331143d5dSDavid Howells 10454566b2cSNick Piggin page = grab_cache_page_write_begin(mapping, index, flags); 1054343d008SDavid Howells if (!page) 10615b4650eSNick Piggin return -ENOMEM; 10715b4650eSNick Piggin 10809cbfeafSKirill A. Shutemov if (!PageUptodate(page) && len != PAGE_SIZE) { 109e8e581a8SDavid Howells ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page); 11031143d5dSDavid Howells if (ret < 0) { 1116d06b0d2SDavid Howells unlock_page(page); 1126d06b0d2SDavid Howells put_page(page); 11331143d5dSDavid Howells _leave(" = %d [prep]", ret); 11431143d5dSDavid Howells return ret; 11531143d5dSDavid Howells } 11615b4650eSNick Piggin SetPageUptodate(page); 11731143d5dSDavid Howells } 11831143d5dSDavid Howells 1196d06b0d2SDavid Howells /* page won't leak in error case: it eventually gets cleaned off LRU */ 1206d06b0d2SDavid Howells *pagep = page; 1216d06b0d2SDavid Howells 12231143d5dSDavid Howells try_again: 1234343d008SDavid Howells /* See if this page is already partially written in a way that we can 1244343d008SDavid Howells * merge the new write with. 1254343d008SDavid Howells */ 1264343d008SDavid Howells t = f = 0; 1274343d008SDavid Howells if (PagePrivate(page)) { 1284343d008SDavid Howells priv = page_private(page); 1294343d008SDavid Howells f = priv & AFS_PRIV_MAX; 1304343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 1314343d008SDavid Howells ASSERTCMP(f, <=, t); 13231143d5dSDavid Howells } 13331143d5dSDavid Howells 1344343d008SDavid Howells if (f != t) { 1354343d008SDavid Howells if (to < f || from > t) 1364343d008SDavid Howells goto flush_conflicting_write; 1374343d008SDavid Howells if (from < f) 1384343d008SDavid Howells f = from; 1394343d008SDavid Howells if (to > t) 1404343d008SDavid Howells t = to; 1414343d008SDavid Howells } else { 1424343d008SDavid Howells f = from; 1434343d008SDavid Howells t = to; 14431143d5dSDavid Howells } 14531143d5dSDavid Howells 1464343d008SDavid Howells priv = (unsigned long)t << AFS_PRIV_SHIFT; 1474343d008SDavid Howells priv |= f; 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) 207e8e581a8SDavid Howells return ret; 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"); 21515b4650eSNick Piggin unlock_page(page); 21609cbfeafSKirill A. Shutemov put_page(page); 21731143d5dSDavid Howells 21815b4650eSNick Piggin return copied; 21931143d5dSDavid Howells } 22031143d5dSDavid Howells 22131143d5dSDavid Howells /* 22231143d5dSDavid Howells * kill all the pages in the given range 22331143d5dSDavid Howells */ 2244343d008SDavid Howells static void afs_kill_pages(struct address_space *mapping, 22531143d5dSDavid Howells pgoff_t first, pgoff_t last) 22631143d5dSDavid Howells { 2274343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 22831143d5dSDavid Howells struct pagevec pv; 22931143d5dSDavid Howells unsigned count, loop; 23031143d5dSDavid Howells 23131143d5dSDavid Howells _enter("{%x:%u},%lx-%lx", 23231143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 23331143d5dSDavid Howells 23431143d5dSDavid Howells pagevec_init(&pv, 0); 23531143d5dSDavid Howells 23631143d5dSDavid Howells do { 23731143d5dSDavid Howells _debug("kill %lx-%lx", first, last); 23831143d5dSDavid Howells 23931143d5dSDavid Howells count = last - first + 1; 24031143d5dSDavid Howells if (count > PAGEVEC_SIZE) 24131143d5dSDavid Howells count = PAGEVEC_SIZE; 2424343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 24331143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 24431143d5dSDavid Howells 24531143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 2467286a35eSDavid Howells struct page *page = pv.pages[loop]; 2477286a35eSDavid Howells ClearPageUptodate(page); 2487286a35eSDavid Howells SetPageError(page); 2494343d008SDavid Howells end_page_writeback(page); 2504343d008SDavid Howells if (page->index >= first) 2514343d008SDavid Howells first = page->index + 1; 2524343d008SDavid Howells lock_page(page); 2534343d008SDavid Howells generic_error_remove_page(mapping, page); 2544343d008SDavid Howells } 2554343d008SDavid Howells 2564343d008SDavid Howells __pagevec_release(&pv); 2574343d008SDavid Howells } while (first <= last); 2584343d008SDavid Howells 2594343d008SDavid Howells _leave(""); 2604343d008SDavid Howells } 2614343d008SDavid Howells 2624343d008SDavid Howells /* 2634343d008SDavid Howells * Redirty all the pages in a given range. 2644343d008SDavid Howells */ 2654343d008SDavid Howells static void afs_redirty_pages(struct writeback_control *wbc, 2664343d008SDavid Howells struct address_space *mapping, 2674343d008SDavid Howells pgoff_t first, pgoff_t last) 2684343d008SDavid Howells { 2694343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 2704343d008SDavid Howells struct pagevec pv; 2714343d008SDavid Howells unsigned count, loop; 2724343d008SDavid Howells 2734343d008SDavid Howells _enter("{%x:%u},%lx-%lx", 2744343d008SDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 2754343d008SDavid Howells 2764343d008SDavid Howells pagevec_init(&pv, 0); 2774343d008SDavid Howells 2784343d008SDavid Howells do { 2794343d008SDavid Howells _debug("redirty %lx-%lx", first, last); 2804343d008SDavid Howells 2814343d008SDavid Howells count = last - first + 1; 2824343d008SDavid Howells if (count > PAGEVEC_SIZE) 2834343d008SDavid Howells count = PAGEVEC_SIZE; 2844343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 2854343d008SDavid Howells ASSERTCMP(pv.nr, ==, count); 2864343d008SDavid Howells 2874343d008SDavid Howells for (loop = 0; loop < count; loop++) { 2884343d008SDavid Howells struct page *page = pv.pages[loop]; 2894343d008SDavid Howells 2904343d008SDavid Howells redirty_page_for_writepage(wbc, page); 2917286a35eSDavid Howells end_page_writeback(page); 2927286a35eSDavid Howells if (page->index >= first) 2937286a35eSDavid Howells first = page->index + 1; 29431143d5dSDavid Howells } 29531143d5dSDavid Howells 29631143d5dSDavid Howells __pagevec_release(&pv); 2974343d008SDavid Howells } while (first <= last); 29831143d5dSDavid Howells 29931143d5dSDavid Howells _leave(""); 30031143d5dSDavid Howells } 30131143d5dSDavid Howells 30231143d5dSDavid Howells /* 303d2ddc776SDavid Howells * write to a file 304d2ddc776SDavid Howells */ 3054343d008SDavid Howells static int afs_store_data(struct address_space *mapping, 3064343d008SDavid Howells pgoff_t first, pgoff_t last, 307d2ddc776SDavid Howells unsigned offset, unsigned to) 308d2ddc776SDavid Howells { 3094343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 310d2ddc776SDavid Howells struct afs_fs_cursor fc; 3114343d008SDavid Howells struct afs_wb_key *wbk = NULL; 3124343d008SDavid Howells struct list_head *p; 3134343d008SDavid Howells int ret = -ENOKEY, ret2; 314d2ddc776SDavid Howells 3154343d008SDavid Howells _enter("%s{%x:%u.%u},%lx,%lx,%x,%x", 316d2ddc776SDavid Howells vnode->volume->name, 317d2ddc776SDavid Howells vnode->fid.vid, 318d2ddc776SDavid Howells vnode->fid.vnode, 319d2ddc776SDavid Howells vnode->fid.unique, 320d2ddc776SDavid Howells first, last, offset, to); 321d2ddc776SDavid Howells 3224343d008SDavid Howells spin_lock(&vnode->wb_lock); 3234343d008SDavid Howells p = vnode->wb_keys.next; 3244343d008SDavid Howells 3254343d008SDavid Howells /* Iterate through the list looking for a valid key to use. */ 3264343d008SDavid Howells try_next_key: 3274343d008SDavid Howells while (p != &vnode->wb_keys) { 3284343d008SDavid Howells wbk = list_entry(p, struct afs_wb_key, vnode_link); 3294343d008SDavid Howells _debug("wbk %u", key_serial(wbk->key)); 3304343d008SDavid Howells ret2 = key_validate(wbk->key); 3314343d008SDavid Howells if (ret2 == 0) 3324343d008SDavid Howells goto found_key; 3334343d008SDavid Howells if (ret == -ENOKEY) 3344343d008SDavid Howells ret = ret2; 3354343d008SDavid Howells p = p->next; 3364343d008SDavid Howells } 3374343d008SDavid Howells 3384343d008SDavid Howells spin_unlock(&vnode->wb_lock); 3394343d008SDavid Howells afs_put_wb_key(wbk); 3404343d008SDavid Howells _leave(" = %d [no keys]", ret); 3414343d008SDavid Howells return ret; 3424343d008SDavid Howells 3434343d008SDavid Howells found_key: 3444343d008SDavid Howells refcount_inc(&wbk->usage); 3454343d008SDavid Howells spin_unlock(&vnode->wb_lock); 3464343d008SDavid Howells 3474343d008SDavid Howells _debug("USE WB KEY %u", key_serial(wbk->key)); 3484343d008SDavid Howells 349d2ddc776SDavid Howells ret = -ERESTARTSYS; 3504343d008SDavid Howells if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) { 351d2ddc776SDavid Howells while (afs_select_fileserver(&fc)) { 352d2ddc776SDavid Howells fc.cb_break = vnode->cb_break + vnode->cb_s_break; 3534343d008SDavid Howells afs_fs_store_data(&fc, mapping, first, last, offset, to); 354d2ddc776SDavid Howells } 355d2ddc776SDavid Howells 356d2ddc776SDavid Howells afs_check_for_remote_deletion(&fc, fc.vnode); 357d2ddc776SDavid Howells afs_vnode_commit_status(&fc, vnode, fc.cb_break); 358d2ddc776SDavid Howells ret = afs_end_vnode_operation(&fc); 359d2ddc776SDavid Howells } 360d2ddc776SDavid Howells 3614343d008SDavid Howells switch (ret) { 3624343d008SDavid Howells case -EACCES: 3634343d008SDavid Howells case -EPERM: 3644343d008SDavid Howells case -ENOKEY: 3654343d008SDavid Howells case -EKEYEXPIRED: 3664343d008SDavid Howells case -EKEYREJECTED: 3674343d008SDavid Howells case -EKEYREVOKED: 3684343d008SDavid Howells _debug("next"); 3694343d008SDavid Howells spin_lock(&vnode->wb_lock); 3704343d008SDavid Howells p = wbk->vnode_link.next; 3714343d008SDavid Howells afs_put_wb_key(wbk); 3724343d008SDavid Howells goto try_next_key; 3734343d008SDavid Howells } 3744343d008SDavid Howells 3754343d008SDavid Howells afs_put_wb_key(wbk); 376d2ddc776SDavid Howells _leave(" = %d", ret); 377d2ddc776SDavid Howells return ret; 378d2ddc776SDavid Howells } 379d2ddc776SDavid Howells 380d2ddc776SDavid Howells /* 3814343d008SDavid Howells * Synchronously write back the locked page and any subsequent non-locked dirty 3824343d008SDavid Howells * pages. 38331143d5dSDavid Howells */ 3844343d008SDavid Howells static int afs_write_back_from_locked_page(struct address_space *mapping, 3854343d008SDavid Howells struct writeback_control *wbc, 3864343d008SDavid Howells struct page *primary_page, 3874343d008SDavid Howells pgoff_t final_page) 38831143d5dSDavid Howells { 38931143d5dSDavid Howells struct page *pages[8], *page; 3904343d008SDavid Howells unsigned long count, priv; 3914343d008SDavid Howells unsigned n, offset, to, f, t; 39231143d5dSDavid Howells pgoff_t start, first, last; 39331143d5dSDavid Howells int loop, ret; 39431143d5dSDavid Howells 39531143d5dSDavid Howells _enter(",%lx", primary_page->index); 39631143d5dSDavid Howells 39731143d5dSDavid Howells count = 1; 39831143d5dSDavid Howells if (test_set_page_writeback(primary_page)) 39931143d5dSDavid Howells BUG(); 40031143d5dSDavid Howells 4014343d008SDavid Howells /* Find all consecutive lockable dirty pages that have contiguous 4024343d008SDavid Howells * written regions, stopping when we find a page that is not 4034343d008SDavid Howells * immediately lockable, is not dirty or is missing, or we reach the 4044343d008SDavid Howells * end of the range. 4054343d008SDavid Howells */ 40631143d5dSDavid Howells start = primary_page->index; 4074343d008SDavid Howells priv = page_private(primary_page); 4084343d008SDavid Howells offset = priv & AFS_PRIV_MAX; 4094343d008SDavid Howells to = priv >> AFS_PRIV_SHIFT; 4104343d008SDavid Howells 4114343d008SDavid Howells WARN_ON(offset == to); 4124343d008SDavid Howells 4134343d008SDavid Howells if (start >= final_page || to < PAGE_SIZE) 41431143d5dSDavid Howells goto no_more; 4154343d008SDavid Howells 41631143d5dSDavid Howells start++; 41731143d5dSDavid Howells do { 41831143d5dSDavid Howells _debug("more %lx [%lx]", start, count); 4194343d008SDavid Howells n = final_page - start + 1; 42031143d5dSDavid Howells if (n > ARRAY_SIZE(pages)) 42131143d5dSDavid Howells n = ARRAY_SIZE(pages); 4224343d008SDavid Howells n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages); 42331143d5dSDavid Howells _debug("fgpc %u", n); 42431143d5dSDavid Howells if (n == 0) 42531143d5dSDavid Howells goto no_more; 42631143d5dSDavid Howells if (pages[0]->index != start) { 4279d577b6aSDavid Howells do { 4289d577b6aSDavid Howells put_page(pages[--n]); 4299d577b6aSDavid Howells } while (n > 0); 43031143d5dSDavid Howells goto no_more; 43131143d5dSDavid Howells } 43231143d5dSDavid Howells 43331143d5dSDavid Howells for (loop = 0; loop < n; loop++) { 4344343d008SDavid Howells if (to != PAGE_SIZE) 4354343d008SDavid Howells break; 43631143d5dSDavid Howells page = pages[loop]; 4374343d008SDavid Howells if (page->index > final_page) 43831143d5dSDavid Howells break; 439529ae9aaSNick Piggin if (!trylock_page(page)) 44031143d5dSDavid Howells break; 4414343d008SDavid Howells if (!PageDirty(page) || PageWriteback(page)) { 44231143d5dSDavid Howells unlock_page(page); 44331143d5dSDavid Howells break; 44431143d5dSDavid Howells } 4454343d008SDavid Howells 4464343d008SDavid Howells priv = page_private(page); 4474343d008SDavid Howells f = priv & AFS_PRIV_MAX; 4484343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 4494343d008SDavid Howells if (f != 0) { 4504343d008SDavid Howells unlock_page(page); 4514343d008SDavid Howells break; 4524343d008SDavid Howells } 4534343d008SDavid Howells to = t; 4544343d008SDavid Howells 45531143d5dSDavid Howells if (!clear_page_dirty_for_io(page)) 45631143d5dSDavid Howells BUG(); 45731143d5dSDavid Howells if (test_set_page_writeback(page)) 45831143d5dSDavid Howells BUG(); 45931143d5dSDavid Howells unlock_page(page); 46031143d5dSDavid Howells put_page(page); 46131143d5dSDavid Howells } 46231143d5dSDavid Howells count += loop; 46331143d5dSDavid Howells if (loop < n) { 46431143d5dSDavid Howells for (; loop < n; loop++) 46531143d5dSDavid Howells put_page(pages[loop]); 46631143d5dSDavid Howells goto no_more; 46731143d5dSDavid Howells } 46831143d5dSDavid Howells 46931143d5dSDavid Howells start += loop; 4704343d008SDavid Howells } while (start <= final_page && count < 65536); 47131143d5dSDavid Howells 47231143d5dSDavid Howells no_more: 4734343d008SDavid Howells /* We now have a contiguous set of dirty pages, each with writeback 4744343d008SDavid Howells * set; the first page is still locked at this point, but all the rest 4754343d008SDavid Howells * have been unlocked. 4764343d008SDavid Howells */ 4774343d008SDavid Howells unlock_page(primary_page); 4784343d008SDavid Howells 47931143d5dSDavid Howells first = primary_page->index; 48031143d5dSDavid Howells last = first + count - 1; 48131143d5dSDavid Howells 48231143d5dSDavid Howells _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); 48331143d5dSDavid Howells 4844343d008SDavid Howells ret = afs_store_data(mapping, first, last, offset, to); 48531143d5dSDavid Howells switch (ret) { 4864343d008SDavid Howells case 0: 4874343d008SDavid Howells ret = count; 4884343d008SDavid Howells break; 4894343d008SDavid Howells 4904343d008SDavid Howells default: 4914343d008SDavid Howells pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); 4924343d008SDavid Howells /* Fall through */ 4934343d008SDavid Howells case -EACCES: 4944343d008SDavid Howells case -EPERM: 4954343d008SDavid Howells case -ENOKEY: 4964343d008SDavid Howells case -EKEYEXPIRED: 4974343d008SDavid Howells case -EKEYREJECTED: 4984343d008SDavid Howells case -EKEYREVOKED: 4994343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 5004343d008SDavid Howells mapping_set_error(mapping, ret); 5014343d008SDavid Howells break; 5024343d008SDavid Howells 50331143d5dSDavid Howells case -EDQUOT: 50431143d5dSDavid Howells case -ENOSPC: 5054343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 5064343d008SDavid Howells mapping_set_error(mapping, -ENOSPC); 50731143d5dSDavid Howells break; 5084343d008SDavid Howells 50931143d5dSDavid Howells case -EROFS: 51031143d5dSDavid Howells case -EIO: 51131143d5dSDavid Howells case -EREMOTEIO: 51231143d5dSDavid Howells case -EFBIG: 51331143d5dSDavid Howells case -ENOENT: 51431143d5dSDavid Howells case -ENOMEDIUM: 51531143d5dSDavid Howells case -ENXIO: 5164343d008SDavid Howells afs_kill_pages(mapping, first, last); 5174343d008SDavid Howells mapping_set_error(mapping, ret); 51831143d5dSDavid Howells break; 51931143d5dSDavid Howells } 52031143d5dSDavid Howells 52131143d5dSDavid Howells _leave(" = %d", ret); 52231143d5dSDavid Howells return ret; 52331143d5dSDavid Howells } 52431143d5dSDavid Howells 52531143d5dSDavid Howells /* 52631143d5dSDavid Howells * write a page back to the server 52731143d5dSDavid Howells * - the caller locked the page for us 52831143d5dSDavid Howells */ 52931143d5dSDavid Howells int afs_writepage(struct page *page, struct writeback_control *wbc) 53031143d5dSDavid Howells { 53131143d5dSDavid Howells int ret; 53231143d5dSDavid Howells 53331143d5dSDavid Howells _enter("{%lx},", page->index); 53431143d5dSDavid Howells 5354343d008SDavid Howells ret = afs_write_back_from_locked_page(page->mapping, wbc, page, 5364343d008SDavid Howells wbc->range_end >> PAGE_SHIFT); 53731143d5dSDavid Howells if (ret < 0) { 53831143d5dSDavid Howells _leave(" = %d", ret); 53931143d5dSDavid Howells return 0; 54031143d5dSDavid Howells } 54131143d5dSDavid Howells 54231143d5dSDavid Howells wbc->nr_to_write -= ret; 54331143d5dSDavid Howells 54431143d5dSDavid Howells _leave(" = 0"); 54531143d5dSDavid Howells return 0; 54631143d5dSDavid Howells } 54731143d5dSDavid Howells 54831143d5dSDavid Howells /* 54931143d5dSDavid Howells * write a region of pages back to the server 55031143d5dSDavid Howells */ 551c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping, 55231143d5dSDavid Howells struct writeback_control *wbc, 55331143d5dSDavid Howells pgoff_t index, pgoff_t end, pgoff_t *_next) 55431143d5dSDavid Howells { 55531143d5dSDavid Howells struct page *page; 55631143d5dSDavid Howells int ret, n; 55731143d5dSDavid Howells 55831143d5dSDavid Howells _enter(",,%lx,%lx,", index, end); 55931143d5dSDavid Howells 56031143d5dSDavid Howells do { 56131143d5dSDavid Howells n = find_get_pages_tag(mapping, &index, PAGECACHE_TAG_DIRTY, 56231143d5dSDavid Howells 1, &page); 56331143d5dSDavid Howells if (!n) 56431143d5dSDavid Howells break; 56531143d5dSDavid Howells 56631143d5dSDavid Howells _debug("wback %lx", page->index); 56731143d5dSDavid Howells 56831143d5dSDavid Howells if (page->index > end) { 56931143d5dSDavid Howells *_next = index; 57009cbfeafSKirill A. Shutemov put_page(page); 57131143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 57231143d5dSDavid Howells return 0; 57331143d5dSDavid Howells } 57431143d5dSDavid Howells 57531143d5dSDavid Howells /* at this point we hold neither mapping->tree_lock nor lock on 57631143d5dSDavid Howells * the page itself: the page may be truncated or invalidated 57731143d5dSDavid Howells * (changing page->mapping to NULL), or even swizzled back from 57831143d5dSDavid Howells * swapper_space to tmpfs file mapping 57931143d5dSDavid Howells */ 5804343d008SDavid Howells ret = lock_page_killable(page); 5814343d008SDavid Howells if (ret < 0) { 5824343d008SDavid Howells put_page(page); 5834343d008SDavid Howells _leave(" = %d", ret); 5844343d008SDavid Howells return ret; 5854343d008SDavid Howells } 58631143d5dSDavid Howells 587c5051c7bSDavid Howells if (page->mapping != mapping || !PageDirty(page)) { 58831143d5dSDavid Howells unlock_page(page); 58909cbfeafSKirill A. Shutemov put_page(page); 59031143d5dSDavid Howells continue; 59131143d5dSDavid Howells } 59231143d5dSDavid Howells 593c5051c7bSDavid Howells if (PageWriteback(page)) { 594c5051c7bSDavid Howells unlock_page(page); 59531143d5dSDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) 59631143d5dSDavid Howells wait_on_page_writeback(page); 59729c8bbbdSDavid Howells put_page(page); 59831143d5dSDavid Howells continue; 59931143d5dSDavid Howells } 60031143d5dSDavid Howells 60165a15109SDavid Howells if (!clear_page_dirty_for_io(page)) 60265a15109SDavid Howells BUG(); 6034343d008SDavid Howells ret = afs_write_back_from_locked_page(mapping, wbc, page, end); 60409cbfeafSKirill A. Shutemov put_page(page); 60531143d5dSDavid Howells if (ret < 0) { 60631143d5dSDavid Howells _leave(" = %d", ret); 60731143d5dSDavid Howells return ret; 60831143d5dSDavid Howells } 60931143d5dSDavid Howells 61031143d5dSDavid Howells wbc->nr_to_write -= ret; 61131143d5dSDavid Howells 61231143d5dSDavid Howells cond_resched(); 61331143d5dSDavid Howells } while (index < end && wbc->nr_to_write > 0); 61431143d5dSDavid Howells 61531143d5dSDavid Howells *_next = index; 61631143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 61731143d5dSDavid Howells return 0; 61831143d5dSDavid Howells } 61931143d5dSDavid Howells 62031143d5dSDavid Howells /* 62131143d5dSDavid Howells * write some of the pending data back to the server 62231143d5dSDavid Howells */ 62331143d5dSDavid Howells int afs_writepages(struct address_space *mapping, 62431143d5dSDavid Howells struct writeback_control *wbc) 62531143d5dSDavid Howells { 62631143d5dSDavid Howells pgoff_t start, end, next; 62731143d5dSDavid Howells int ret; 62831143d5dSDavid Howells 62931143d5dSDavid Howells _enter(""); 63031143d5dSDavid Howells 63131143d5dSDavid Howells if (wbc->range_cyclic) { 63231143d5dSDavid Howells start = mapping->writeback_index; 63331143d5dSDavid Howells end = -1; 63431143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 6351b430beeSWu Fengguang if (start > 0 && wbc->nr_to_write > 0 && ret == 0) 63631143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, start, 63731143d5dSDavid Howells &next); 63831143d5dSDavid Howells mapping->writeback_index = next; 63931143d5dSDavid Howells } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { 64009cbfeafSKirill A. Shutemov end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT); 64131143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, end, &next); 64231143d5dSDavid Howells if (wbc->nr_to_write > 0) 64331143d5dSDavid Howells mapping->writeback_index = next; 64431143d5dSDavid Howells } else { 64509cbfeafSKirill A. Shutemov start = wbc->range_start >> PAGE_SHIFT; 64609cbfeafSKirill A. Shutemov end = wbc->range_end >> PAGE_SHIFT; 64731143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 64831143d5dSDavid Howells } 64931143d5dSDavid Howells 65031143d5dSDavid Howells _leave(" = %d", ret); 65131143d5dSDavid Howells return ret; 65231143d5dSDavid Howells } 65331143d5dSDavid Howells 65431143d5dSDavid Howells /* 65531143d5dSDavid Howells * completion of write to server 65631143d5dSDavid Howells */ 65731143d5dSDavid Howells void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call) 65831143d5dSDavid Howells { 65931143d5dSDavid Howells struct pagevec pv; 66031143d5dSDavid Howells unsigned count, loop; 66131143d5dSDavid Howells pgoff_t first = call->first, last = call->last; 66231143d5dSDavid Howells 66331143d5dSDavid Howells _enter("{%x:%u},{%lx-%lx}", 66431143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 66531143d5dSDavid Howells 66631143d5dSDavid Howells pagevec_init(&pv, 0); 66731143d5dSDavid Howells 66831143d5dSDavid Howells do { 6695bbf5d39SDavid Howells _debug("done %lx-%lx", first, last); 67031143d5dSDavid Howells 67131143d5dSDavid Howells count = last - first + 1; 67231143d5dSDavid Howells if (count > PAGEVEC_SIZE) 67331143d5dSDavid Howells count = PAGEVEC_SIZE; 6744343d008SDavid Howells pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, 6754343d008SDavid Howells first, count, pv.pages); 67631143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 67731143d5dSDavid Howells 67831143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 6794343d008SDavid Howells set_page_private(pv.pages[loop], 0); 6804343d008SDavid Howells end_page_writeback(pv.pages[loop]); 68131143d5dSDavid Howells } 68231143d5dSDavid Howells first += count; 68331143d5dSDavid Howells __pagevec_release(&pv); 6845bbf5d39SDavid Howells } while (first <= last); 68531143d5dSDavid Howells 6864343d008SDavid Howells afs_prune_wb_keys(vnode); 68731143d5dSDavid Howells _leave(""); 68831143d5dSDavid Howells } 68931143d5dSDavid Howells 69031143d5dSDavid Howells /* 69131143d5dSDavid Howells * write to an AFS file 69231143d5dSDavid Howells */ 69350b5551dSAl Viro ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) 69431143d5dSDavid Howells { 695496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); 69631143d5dSDavid Howells ssize_t result; 69750b5551dSAl Viro size_t count = iov_iter_count(from); 69831143d5dSDavid Howells 69950b5551dSAl Viro _enter("{%x.%u},{%zu},", 70050b5551dSAl Viro vnode->fid.vid, vnode->fid.vnode, count); 70131143d5dSDavid Howells 70231143d5dSDavid Howells if (IS_SWAPFILE(&vnode->vfs_inode)) { 70331143d5dSDavid Howells printk(KERN_INFO 70431143d5dSDavid Howells "AFS: Attempt to write to active swap file!\n"); 70531143d5dSDavid Howells return -EBUSY; 70631143d5dSDavid Howells } 70731143d5dSDavid Howells 70831143d5dSDavid Howells if (!count) 70931143d5dSDavid Howells return 0; 71031143d5dSDavid Howells 71150b5551dSAl Viro result = generic_file_write_iter(iocb, from); 71231143d5dSDavid Howells 71331143d5dSDavid Howells _leave(" = %zd", result); 71431143d5dSDavid Howells return result; 71531143d5dSDavid Howells } 71631143d5dSDavid Howells 71731143d5dSDavid Howells /* 71831143d5dSDavid Howells * flush any dirty pages for this process, and check for write errors. 71931143d5dSDavid Howells * - the return status from this call provides a reliable indication of 72031143d5dSDavid Howells * whether any write errors occurred for this process. 72131143d5dSDavid Howells */ 72202c24a82SJosef Bacik int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 72331143d5dSDavid Howells { 7243c981bfcSAl Viro struct inode *inode = file_inode(file); 7253c981bfcSAl Viro struct afs_vnode *vnode = AFS_FS_I(inode); 72631143d5dSDavid Howells 7273c981bfcSAl Viro _enter("{%x:%u},{n=%pD},%d", 7283c981bfcSAl Viro vnode->fid.vid, vnode->fid.vnode, file, 72931143d5dSDavid Howells datasync); 73031143d5dSDavid Howells 7314343d008SDavid Howells return file_write_and_wait_range(file, start, end); 73231143d5dSDavid Howells } 7339b3f26c9SDavid Howells 7349b3f26c9SDavid Howells /* 73558fed94dSDavid Howells * Flush out all outstanding writes on a file opened for writing when it is 73658fed94dSDavid Howells * closed. 73758fed94dSDavid Howells */ 73858fed94dSDavid Howells int afs_flush(struct file *file, fl_owner_t id) 73958fed94dSDavid Howells { 74058fed94dSDavid Howells _enter(""); 74158fed94dSDavid Howells 74258fed94dSDavid Howells if ((file->f_mode & FMODE_WRITE) == 0) 74358fed94dSDavid Howells return 0; 74458fed94dSDavid Howells 74558fed94dSDavid Howells return vfs_fsync(file, 0); 74658fed94dSDavid Howells } 74758fed94dSDavid Howells 74858fed94dSDavid Howells /* 7499b3f26c9SDavid Howells * notification that a previously read-only page is about to become writable 7509b3f26c9SDavid Howells * - if it returns an error, the caller will deliver a bus error signal 7519b3f26c9SDavid Howells */ 7529b3f26c9SDavid Howells int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page) 7539b3f26c9SDavid Howells { 7549b3f26c9SDavid Howells struct afs_vnode *vnode = AFS_FS_I(vma->vm_file->f_mapping->host); 7559b3f26c9SDavid Howells 7569b3f26c9SDavid Howells _enter("{{%x:%u}},{%lx}", 7579b3f26c9SDavid Howells vnode->fid.vid, vnode->fid.vnode, page->index); 7589b3f26c9SDavid Howells 7599b3f26c9SDavid Howells /* wait for the page to be written to the cache before we allow it to 7609b3f26c9SDavid Howells * be modified */ 7619b3f26c9SDavid Howells #ifdef CONFIG_AFS_FSCACHE 7629b3f26c9SDavid Howells fscache_wait_on_page_write(vnode->cache, page); 7639b3f26c9SDavid Howells #endif 7649b3f26c9SDavid Howells 7659b3f26c9SDavid Howells _leave(" = 0"); 7669b3f26c9SDavid Howells return 0; 7679b3f26c9SDavid Howells } 7684343d008SDavid Howells 7694343d008SDavid Howells /* 7704343d008SDavid Howells * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. 7714343d008SDavid Howells */ 7724343d008SDavid Howells void afs_prune_wb_keys(struct afs_vnode *vnode) 7734343d008SDavid Howells { 7744343d008SDavid Howells LIST_HEAD(graveyard); 7754343d008SDavid Howells struct afs_wb_key *wbk, *tmp; 7764343d008SDavid Howells 7774343d008SDavid Howells /* Discard unused keys */ 7784343d008SDavid Howells spin_lock(&vnode->wb_lock); 7794343d008SDavid Howells 7804343d008SDavid Howells if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && 7814343d008SDavid Howells !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { 7824343d008SDavid Howells list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { 7834343d008SDavid Howells if (refcount_read(&wbk->usage) == 1) 7844343d008SDavid Howells list_move(&wbk->vnode_link, &graveyard); 7854343d008SDavid Howells } 7864343d008SDavid Howells } 7874343d008SDavid Howells 7884343d008SDavid Howells spin_unlock(&vnode->wb_lock); 7894343d008SDavid Howells 7904343d008SDavid Howells while (!list_empty(&graveyard)) { 7914343d008SDavid Howells wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); 7924343d008SDavid Howells list_del(&wbk->vnode_link); 7934343d008SDavid Howells afs_put_wb_key(wbk); 7944343d008SDavid Howells } 7954343d008SDavid Howells } 7964343d008SDavid Howells 7974343d008SDavid Howells /* 7984343d008SDavid Howells * Clean up a page during invalidation. 7994343d008SDavid Howells */ 8004343d008SDavid Howells int afs_launder_page(struct page *page) 8014343d008SDavid Howells { 8024343d008SDavid Howells struct address_space *mapping = page->mapping; 8034343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 8044343d008SDavid Howells unsigned long priv; 8054343d008SDavid Howells unsigned int f, t; 8064343d008SDavid Howells int ret = 0; 8074343d008SDavid Howells 8084343d008SDavid Howells _enter("{%lx}", page->index); 8094343d008SDavid Howells 8104343d008SDavid Howells priv = page_private(page); 8114343d008SDavid Howells if (clear_page_dirty_for_io(page)) { 8124343d008SDavid Howells f = 0; 8134343d008SDavid Howells t = PAGE_SIZE; 8144343d008SDavid Howells if (PagePrivate(page)) { 8154343d008SDavid Howells f = priv & AFS_PRIV_MAX; 8164343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 8174343d008SDavid Howells } 8184343d008SDavid Howells 8194343d008SDavid Howells ret = afs_store_data(mapping, page->index, page->index, t, f); 8204343d008SDavid Howells } 8214343d008SDavid Howells 8224343d008SDavid Howells set_page_private(page, 0); 8234343d008SDavid Howells ClearPagePrivate(page); 8244343d008SDavid Howells 8254343d008SDavid Howells #ifdef CONFIG_AFS_FSCACHE 8264343d008SDavid Howells if (PageFsCache(page)) { 8274343d008SDavid Howells fscache_wait_on_page_write(vnode->cache, page); 8284343d008SDavid Howells fscache_uncache_page(vnode->cache, page); 8294343d008SDavid Howells } 8304343d008SDavid Howells #endif 8314343d008SDavid Howells return ret; 8324343d008SDavid Howells } 833