12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 231143d5dSDavid Howells /* handling of writes to regular files and writing back to the server 331143d5dSDavid Howells * 431143d5dSDavid Howells * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 531143d5dSDavid Howells * Written by David Howells (dhowells@redhat.com) 631143d5dSDavid Howells */ 74343d008SDavid Howells 84af3c9ccSAlexey Dobriyan #include <linux/backing-dev.h> 931143d5dSDavid Howells #include <linux/slab.h> 1031143d5dSDavid Howells #include <linux/fs.h> 1131143d5dSDavid Howells #include <linux/pagemap.h> 1231143d5dSDavid Howells #include <linux/writeback.h> 1331143d5dSDavid Howells #include <linux/pagevec.h> 1431143d5dSDavid Howells #include "internal.h" 1531143d5dSDavid Howells 1631143d5dSDavid Howells /* 1731143d5dSDavid Howells * mark a page as having been made dirty and thus needing writeback 1831143d5dSDavid Howells */ 1931143d5dSDavid Howells int afs_set_page_dirty(struct page *page) 2031143d5dSDavid Howells { 2131143d5dSDavid Howells _enter(""); 2231143d5dSDavid Howells return __set_page_dirty_nobuffers(page); 2331143d5dSDavid Howells } 2431143d5dSDavid Howells 2531143d5dSDavid Howells /* 2631143d5dSDavid Howells * partly or wholly fill a page that's under preparation for writing 2731143d5dSDavid Howells */ 2831143d5dSDavid Howells static int afs_fill_page(struct afs_vnode *vnode, struct key *key, 29e8e581a8SDavid Howells loff_t pos, unsigned int len, struct page *page) 3031143d5dSDavid Howells { 31196ee9cdSDavid Howells struct afs_read *req; 322a0b4f64SDavid Howells size_t p; 332a0b4f64SDavid Howells void *data; 3431143d5dSDavid Howells int ret; 3531143d5dSDavid Howells 365e7f2337SAnton Blanchard _enter(",,%llu", (unsigned long long)pos); 3731143d5dSDavid Howells 382a0b4f64SDavid Howells if (pos >= vnode->vfs_inode.i_size) { 392a0b4f64SDavid Howells p = pos & ~PAGE_MASK; 402a0b4f64SDavid Howells ASSERTCMP(p + len, <=, PAGE_SIZE); 412a0b4f64SDavid Howells data = kmap(page); 422a0b4f64SDavid Howells memset(data + p, 0, len); 432a0b4f64SDavid Howells kunmap(page); 442a0b4f64SDavid Howells return 0; 452a0b4f64SDavid Howells } 462a0b4f64SDavid Howells 47ee102584SZhengyuan Liu req = kzalloc(struct_size(req, array, 1), GFP_KERNEL); 48196ee9cdSDavid Howells if (!req) 49196ee9cdSDavid Howells return -ENOMEM; 50196ee9cdSDavid Howells 51f3ddee8dSDavid Howells refcount_set(&req->usage, 1); 52196ee9cdSDavid Howells req->pos = pos; 53e8e581a8SDavid Howells req->len = len; 54196ee9cdSDavid Howells req->nr_pages = 1; 55f3ddee8dSDavid Howells req->pages = req->array; 56196ee9cdSDavid Howells req->pages[0] = page; 575611ef28SDavid Howells get_page(page); 58196ee9cdSDavid Howells 59d2ddc776SDavid Howells ret = afs_fetch_data(vnode, key, req); 60196ee9cdSDavid Howells afs_put_read(req); 6131143d5dSDavid Howells if (ret < 0) { 6231143d5dSDavid Howells if (ret == -ENOENT) { 6331143d5dSDavid Howells _debug("got NOENT from server" 6431143d5dSDavid Howells " - marking file deleted and stale"); 6531143d5dSDavid Howells set_bit(AFS_VNODE_DELETED, &vnode->flags); 6631143d5dSDavid Howells ret = -ESTALE; 6731143d5dSDavid Howells } 6831143d5dSDavid Howells } 6931143d5dSDavid Howells 7031143d5dSDavid Howells _leave(" = %d", ret); 7131143d5dSDavid Howells return ret; 7231143d5dSDavid Howells } 7331143d5dSDavid Howells 7431143d5dSDavid Howells /* 7531143d5dSDavid Howells * prepare to perform part of a write to a page 7631143d5dSDavid Howells */ 7715b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping, 7815b4650eSNick Piggin loff_t pos, unsigned len, unsigned flags, 7921db2cdcSDavid Howells struct page **_page, void **fsdata) 8031143d5dSDavid Howells { 81496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 8215b4650eSNick Piggin struct page *page; 83215804a9SDavid Howells struct key *key = afs_file_key(file); 844343d008SDavid Howells unsigned long priv; 854343d008SDavid Howells unsigned f, from = pos & (PAGE_SIZE - 1); 864343d008SDavid Howells unsigned t, to = from + len; 8709cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT; 8831143d5dSDavid Howells int ret; 8931143d5dSDavid Howells 903b6492dfSDavid Howells _enter("{%llx:%llu},{%lx},%u,%u", 9115b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, index, from, to); 9231143d5dSDavid Howells 934343d008SDavid Howells /* We want to store information about how much of a page is altered in 944343d008SDavid Howells * page->private. 954343d008SDavid Howells */ 964343d008SDavid Howells BUILD_BUG_ON(PAGE_SIZE > 32768 && sizeof(page->private) < 8); 9731143d5dSDavid Howells 9854566b2cSNick Piggin page = grab_cache_page_write_begin(mapping, index, flags); 994343d008SDavid Howells if (!page) 10015b4650eSNick Piggin return -ENOMEM; 10115b4650eSNick Piggin 10209cbfeafSKirill A. Shutemov if (!PageUptodate(page) && len != PAGE_SIZE) { 103e8e581a8SDavid Howells ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page); 10431143d5dSDavid Howells if (ret < 0) { 1056d06b0d2SDavid Howells unlock_page(page); 1066d06b0d2SDavid Howells put_page(page); 10731143d5dSDavid Howells _leave(" = %d [prep]", ret); 10831143d5dSDavid Howells return ret; 10931143d5dSDavid Howells } 11015b4650eSNick Piggin SetPageUptodate(page); 11131143d5dSDavid Howells } 11231143d5dSDavid Howells 11331143d5dSDavid Howells try_again: 1144343d008SDavid Howells /* See if this page is already partially written in a way that we can 1154343d008SDavid Howells * merge the new write with. 1164343d008SDavid Howells */ 1174343d008SDavid Howells t = f = 0; 1184343d008SDavid Howells if (PagePrivate(page)) { 1194343d008SDavid Howells priv = page_private(page); 1204343d008SDavid Howells f = priv & AFS_PRIV_MAX; 1214343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 1224343d008SDavid Howells ASSERTCMP(f, <=, t); 12331143d5dSDavid Howells } 12431143d5dSDavid Howells 1254343d008SDavid Howells if (f != t) { 1265a039c32SDavid Howells if (PageWriteback(page)) { 1275a039c32SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("alrdy"), 1285a039c32SDavid Howells page->index, priv); 1295a039c32SDavid Howells goto flush_conflicting_write; 1305a039c32SDavid Howells } 1315a813276SDavid Howells /* If the file is being filled locally, allow inter-write 1325a813276SDavid Howells * spaces to be merged into writes. If it's not, only write 1335a813276SDavid Howells * back what the user gives us. 1345a813276SDavid Howells */ 1355a813276SDavid Howells if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) && 1365a813276SDavid Howells (to < f || from > t)) 1374343d008SDavid Howells goto flush_conflicting_write; 13831143d5dSDavid Howells } 13931143d5dSDavid Howells 14021db2cdcSDavid Howells *_page = page; 1414343d008SDavid Howells _leave(" = 0"); 14231143d5dSDavid Howells return 0; 14331143d5dSDavid Howells 1444343d008SDavid Howells /* The previous write and this write aren't adjacent or overlapping, so 1454343d008SDavid Howells * flush the page out. 1464343d008SDavid Howells */ 1474343d008SDavid Howells flush_conflicting_write: 14831143d5dSDavid Howells _debug("flush conflict"); 1494343d008SDavid Howells ret = write_one_page(page); 15021db2cdcSDavid Howells if (ret < 0) 15121db2cdcSDavid Howells goto error; 15231143d5dSDavid Howells 1534343d008SDavid Howells ret = lock_page_killable(page); 15421db2cdcSDavid Howells if (ret < 0) 15521db2cdcSDavid Howells goto error; 15621db2cdcSDavid Howells goto try_again; 15721db2cdcSDavid Howells 15821db2cdcSDavid Howells error: 15921db2cdcSDavid Howells put_page(page); 1604343d008SDavid Howells _leave(" = %d", ret); 1614343d008SDavid Howells return ret; 1624343d008SDavid Howells } 16331143d5dSDavid Howells 16431143d5dSDavid Howells /* 16531143d5dSDavid Howells * finalise part of a write to a page 16631143d5dSDavid Howells */ 16715b4650eSNick Piggin int afs_write_end(struct file *file, struct address_space *mapping, 16815b4650eSNick Piggin loff_t pos, unsigned len, unsigned copied, 16915b4650eSNick Piggin struct page *page, void *fsdata) 17031143d5dSDavid Howells { 171496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 172215804a9SDavid Howells struct key *key = afs_file_key(file); 173f792e3acSDavid Howells unsigned long priv; 174f792e3acSDavid Howells unsigned int f, from = pos & (PAGE_SIZE - 1); 175f792e3acSDavid Howells unsigned int t, to = from + copied; 17631143d5dSDavid Howells loff_t i_size, maybe_i_size; 177e8e581a8SDavid Howells int ret; 17831143d5dSDavid Howells 1793b6492dfSDavid Howells _enter("{%llx:%llu},{%lx}", 18015b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, page->index); 18131143d5dSDavid Howells 18215b4650eSNick Piggin maybe_i_size = pos + copied; 18331143d5dSDavid Howells 18431143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 18531143d5dSDavid Howells if (maybe_i_size > i_size) { 1861f32ef79SDavid Howells write_seqlock(&vnode->cb_lock); 18731143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 18831143d5dSDavid Howells if (maybe_i_size > i_size) 18931143d5dSDavid Howells i_size_write(&vnode->vfs_inode, maybe_i_size); 1901f32ef79SDavid Howells write_sequnlock(&vnode->cb_lock); 19131143d5dSDavid Howells } 19231143d5dSDavid Howells 193e8e581a8SDavid Howells if (!PageUptodate(page)) { 194e8e581a8SDavid Howells if (copied < len) { 195e8e581a8SDavid Howells /* Try and load any missing data from the server. The 196e8e581a8SDavid Howells * unmarshalling routine will take care of clearing any 197e8e581a8SDavid Howells * bits that are beyond the EOF. 198e8e581a8SDavid Howells */ 199e8e581a8SDavid Howells ret = afs_fill_page(vnode, key, pos + copied, 200e8e581a8SDavid Howells len - copied, page); 201e8e581a8SDavid Howells if (ret < 0) 202afae457dSDavid Howells goto out; 203e8e581a8SDavid Howells } 204e8e581a8SDavid Howells SetPageUptodate(page); 205e8e581a8SDavid Howells } 206e8e581a8SDavid Howells 207f792e3acSDavid Howells if (PagePrivate(page)) { 208f792e3acSDavid Howells priv = page_private(page); 209f792e3acSDavid Howells f = priv & AFS_PRIV_MAX; 210f792e3acSDavid Howells t = priv >> AFS_PRIV_SHIFT; 211f792e3acSDavid Howells if (from < f) 212f792e3acSDavid Howells f = from; 213f792e3acSDavid Howells if (to > t) 214f792e3acSDavid Howells t = to; 215f792e3acSDavid Howells priv = (unsigned long)t << AFS_PRIV_SHIFT; 216f792e3acSDavid Howells priv |= f; 217f792e3acSDavid Howells set_page_private(page, priv); 218f792e3acSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("dirty+"), 219f792e3acSDavid Howells page->index, priv); 220f792e3acSDavid Howells } else { 221f792e3acSDavid Howells f = from; 222f792e3acSDavid Howells t = to; 223f792e3acSDavid Howells priv = (unsigned long)t << AFS_PRIV_SHIFT; 224f792e3acSDavid Howells priv |= f; 225f792e3acSDavid Howells attach_page_private(page, (void *)priv); 226f792e3acSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("dirty"), 227f792e3acSDavid Howells page->index, priv); 228f792e3acSDavid Howells } 229f792e3acSDavid Howells 23031143d5dSDavid Howells set_page_dirty(page); 23131143d5dSDavid Howells if (PageDirty(page)) 23231143d5dSDavid Howells _debug("dirtied"); 233afae457dSDavid Howells ret = copied; 234afae457dSDavid Howells 235afae457dSDavid Howells out: 23615b4650eSNick Piggin unlock_page(page); 23709cbfeafSKirill A. Shutemov put_page(page); 238afae457dSDavid Howells return ret; 23931143d5dSDavid Howells } 24031143d5dSDavid Howells 24131143d5dSDavid Howells /* 24231143d5dSDavid Howells * kill all the pages in the given range 24331143d5dSDavid Howells */ 2444343d008SDavid Howells static void afs_kill_pages(struct address_space *mapping, 24531143d5dSDavid Howells pgoff_t first, pgoff_t last) 24631143d5dSDavid Howells { 2474343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 24831143d5dSDavid Howells struct pagevec pv; 24931143d5dSDavid Howells unsigned count, loop; 25031143d5dSDavid Howells 2513b6492dfSDavid Howells _enter("{%llx:%llu},%lx-%lx", 25231143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 25331143d5dSDavid Howells 25486679820SMel Gorman pagevec_init(&pv); 25531143d5dSDavid Howells 25631143d5dSDavid Howells do { 25731143d5dSDavid Howells _debug("kill %lx-%lx", first, last); 25831143d5dSDavid Howells 25931143d5dSDavid Howells count = last - first + 1; 26031143d5dSDavid Howells if (count > PAGEVEC_SIZE) 26131143d5dSDavid Howells count = PAGEVEC_SIZE; 2624343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 26331143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 26431143d5dSDavid Howells 26531143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 2667286a35eSDavid Howells struct page *page = pv.pages[loop]; 2677286a35eSDavid Howells ClearPageUptodate(page); 2687286a35eSDavid Howells SetPageError(page); 2694343d008SDavid Howells end_page_writeback(page); 2704343d008SDavid Howells if (page->index >= first) 2714343d008SDavid Howells first = page->index + 1; 2724343d008SDavid Howells lock_page(page); 2734343d008SDavid Howells generic_error_remove_page(mapping, page); 27421bd68f1SMarc Dionne unlock_page(page); 2754343d008SDavid Howells } 2764343d008SDavid Howells 2774343d008SDavid Howells __pagevec_release(&pv); 2784343d008SDavid Howells } while (first <= last); 2794343d008SDavid Howells 2804343d008SDavid Howells _leave(""); 2814343d008SDavid Howells } 2824343d008SDavid Howells 2834343d008SDavid Howells /* 2844343d008SDavid Howells * Redirty all the pages in a given range. 2854343d008SDavid Howells */ 2864343d008SDavid Howells static void afs_redirty_pages(struct writeback_control *wbc, 2874343d008SDavid Howells struct address_space *mapping, 2884343d008SDavid Howells pgoff_t first, pgoff_t last) 2894343d008SDavid Howells { 2904343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 2914343d008SDavid Howells struct pagevec pv; 2924343d008SDavid Howells unsigned count, loop; 2934343d008SDavid Howells 2943b6492dfSDavid Howells _enter("{%llx:%llu},%lx-%lx", 2954343d008SDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 2964343d008SDavid Howells 297487e2c9fSLinus Torvalds pagevec_init(&pv); 2984343d008SDavid Howells 2994343d008SDavid Howells do { 3004343d008SDavid Howells _debug("redirty %lx-%lx", first, last); 3014343d008SDavid Howells 3024343d008SDavid Howells count = last - first + 1; 3034343d008SDavid Howells if (count > PAGEVEC_SIZE) 3044343d008SDavid Howells count = PAGEVEC_SIZE; 3054343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 3064343d008SDavid Howells ASSERTCMP(pv.nr, ==, count); 3074343d008SDavid Howells 3084343d008SDavid Howells for (loop = 0; loop < count; loop++) { 3094343d008SDavid Howells struct page *page = pv.pages[loop]; 3104343d008SDavid Howells 3114343d008SDavid Howells redirty_page_for_writepage(wbc, page); 3127286a35eSDavid Howells end_page_writeback(page); 3137286a35eSDavid Howells if (page->index >= first) 3147286a35eSDavid Howells first = page->index + 1; 31531143d5dSDavid Howells } 31631143d5dSDavid Howells 31731143d5dSDavid Howells __pagevec_release(&pv); 3184343d008SDavid Howells } while (first <= last); 31931143d5dSDavid Howells 32031143d5dSDavid Howells _leave(""); 32131143d5dSDavid Howells } 32231143d5dSDavid Howells 32331143d5dSDavid Howells /* 324a58823acSDavid Howells * completion of write to server 325a58823acSDavid Howells */ 326a58823acSDavid Howells static void afs_pages_written_back(struct afs_vnode *vnode, 327a58823acSDavid Howells pgoff_t first, pgoff_t last) 328a58823acSDavid Howells { 329a58823acSDavid Howells struct pagevec pv; 330a58823acSDavid Howells unsigned long priv; 331a58823acSDavid Howells unsigned count, loop; 332a58823acSDavid Howells 333a58823acSDavid Howells _enter("{%llx:%llu},{%lx-%lx}", 334a58823acSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 335a58823acSDavid Howells 336a58823acSDavid Howells pagevec_init(&pv); 337a58823acSDavid Howells 338a58823acSDavid Howells do { 339a58823acSDavid Howells _debug("done %lx-%lx", first, last); 340a58823acSDavid Howells 341a58823acSDavid Howells count = last - first + 1; 342a58823acSDavid Howells if (count > PAGEVEC_SIZE) 343a58823acSDavid Howells count = PAGEVEC_SIZE; 344a58823acSDavid Howells pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, 345a58823acSDavid Howells first, count, pv.pages); 346a58823acSDavid Howells ASSERTCMP(pv.nr, ==, count); 347a58823acSDavid Howells 348a58823acSDavid Howells for (loop = 0; loop < count; loop++) { 349fa04a40bSDavid Howells priv = (unsigned long)detach_page_private(pv.pages[loop]); 350a58823acSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("clear"), 351a58823acSDavid Howells pv.pages[loop]->index, priv); 352a58823acSDavid Howells end_page_writeback(pv.pages[loop]); 353a58823acSDavid Howells } 354a58823acSDavid Howells first += count; 355a58823acSDavid Howells __pagevec_release(&pv); 356a58823acSDavid Howells } while (first <= last); 357a58823acSDavid Howells 358a58823acSDavid Howells afs_prune_wb_keys(vnode); 359a58823acSDavid Howells _leave(""); 360a58823acSDavid Howells } 361a58823acSDavid Howells 362a58823acSDavid Howells /* 363e49c7b2fSDavid Howells * Find a key to use for the writeback. We cached the keys used to author the 364e49c7b2fSDavid Howells * writes on the vnode. *_wbk will contain the last writeback key used or NULL 365e49c7b2fSDavid Howells * and we need to start from there if it's set. 366e49c7b2fSDavid Howells */ 367e49c7b2fSDavid Howells static int afs_get_writeback_key(struct afs_vnode *vnode, 368e49c7b2fSDavid Howells struct afs_wb_key **_wbk) 369e49c7b2fSDavid Howells { 370e49c7b2fSDavid Howells struct afs_wb_key *wbk = NULL; 371e49c7b2fSDavid Howells struct list_head *p; 372e49c7b2fSDavid Howells int ret = -ENOKEY, ret2; 373e49c7b2fSDavid Howells 374e49c7b2fSDavid Howells spin_lock(&vnode->wb_lock); 375e49c7b2fSDavid Howells if (*_wbk) 376e49c7b2fSDavid Howells p = (*_wbk)->vnode_link.next; 377e49c7b2fSDavid Howells else 378e49c7b2fSDavid Howells p = vnode->wb_keys.next; 379e49c7b2fSDavid Howells 380e49c7b2fSDavid Howells while (p != &vnode->wb_keys) { 381e49c7b2fSDavid Howells wbk = list_entry(p, struct afs_wb_key, vnode_link); 382e49c7b2fSDavid Howells _debug("wbk %u", key_serial(wbk->key)); 383e49c7b2fSDavid Howells ret2 = key_validate(wbk->key); 384e49c7b2fSDavid Howells if (ret2 == 0) { 385e49c7b2fSDavid Howells refcount_inc(&wbk->usage); 386e49c7b2fSDavid Howells _debug("USE WB KEY %u", key_serial(wbk->key)); 387e49c7b2fSDavid Howells break; 388e49c7b2fSDavid Howells } 389e49c7b2fSDavid Howells 390e49c7b2fSDavid Howells wbk = NULL; 391e49c7b2fSDavid Howells if (ret == -ENOKEY) 392e49c7b2fSDavid Howells ret = ret2; 393e49c7b2fSDavid Howells p = p->next; 394e49c7b2fSDavid Howells } 395e49c7b2fSDavid Howells 396e49c7b2fSDavid Howells spin_unlock(&vnode->wb_lock); 397e49c7b2fSDavid Howells if (*_wbk) 398e49c7b2fSDavid Howells afs_put_wb_key(*_wbk); 399e49c7b2fSDavid Howells *_wbk = wbk; 400e49c7b2fSDavid Howells return 0; 401e49c7b2fSDavid Howells } 402e49c7b2fSDavid Howells 403e49c7b2fSDavid Howells static void afs_store_data_success(struct afs_operation *op) 404e49c7b2fSDavid Howells { 405e49c7b2fSDavid Howells struct afs_vnode *vnode = op->file[0].vnode; 406e49c7b2fSDavid Howells 407da8d0755SDavid Howells op->ctime = op->file[0].scb.status.mtime_client; 408e49c7b2fSDavid Howells afs_vnode_commit_status(op, &op->file[0]); 409e49c7b2fSDavid Howells if (op->error == 0) { 410d383e346SDavid Howells if (!op->store.laundering) 411e49c7b2fSDavid Howells afs_pages_written_back(vnode, op->store.first, op->store.last); 412e49c7b2fSDavid Howells afs_stat_v(vnode, n_stores); 413e49c7b2fSDavid Howells atomic_long_add((op->store.last * PAGE_SIZE + op->store.last_to) - 414e49c7b2fSDavid Howells (op->store.first * PAGE_SIZE + op->store.first_offset), 415e49c7b2fSDavid Howells &afs_v2net(vnode)->n_store_bytes); 416e49c7b2fSDavid Howells } 417e49c7b2fSDavid Howells } 418e49c7b2fSDavid Howells 419e49c7b2fSDavid Howells static const struct afs_operation_ops afs_store_data_operation = { 420e49c7b2fSDavid Howells .issue_afs_rpc = afs_fs_store_data, 421e49c7b2fSDavid Howells .issue_yfs_rpc = yfs_fs_store_data, 422e49c7b2fSDavid Howells .success = afs_store_data_success, 423e49c7b2fSDavid Howells }; 424e49c7b2fSDavid Howells 425e49c7b2fSDavid Howells /* 426d2ddc776SDavid Howells * write to a file 42731143d5dSDavid Howells */ 4284343d008SDavid Howells static int afs_store_data(struct address_space *mapping, 4294343d008SDavid Howells pgoff_t first, pgoff_t last, 430d383e346SDavid Howells unsigned offset, unsigned to, bool laundering) 43131143d5dSDavid Howells { 4324343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 433e49c7b2fSDavid Howells struct afs_operation *op; 4344343d008SDavid Howells struct afs_wb_key *wbk = NULL; 435e49c7b2fSDavid Howells int ret; 436d2ddc776SDavid Howells 4373b6492dfSDavid Howells _enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x", 438d2ddc776SDavid Howells vnode->volume->name, 439d2ddc776SDavid Howells vnode->fid.vid, 440d2ddc776SDavid Howells vnode->fid.vnode, 441d2ddc776SDavid Howells vnode->fid.unique, 442d2ddc776SDavid Howells first, last, offset, to); 443d2ddc776SDavid Howells 444e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 445e49c7b2fSDavid Howells if (ret) { 4464343d008SDavid Howells _leave(" = %d [no keys]", ret); 4474343d008SDavid Howells return ret; 448d2ddc776SDavid Howells } 449d2ddc776SDavid Howells 450e49c7b2fSDavid Howells op = afs_alloc_operation(wbk->key, vnode->volume); 451e49c7b2fSDavid Howells if (IS_ERR(op)) { 452e49c7b2fSDavid Howells afs_put_wb_key(wbk); 453e49c7b2fSDavid Howells return -ENOMEM; 454d2ddc776SDavid Howells } 455d2ddc776SDavid Howells 456e49c7b2fSDavid Howells afs_op_set_vnode(op, 0, vnode); 457e49c7b2fSDavid Howells op->file[0].dv_delta = 1; 458e49c7b2fSDavid Howells op->store.mapping = mapping; 459e49c7b2fSDavid Howells op->store.first = first; 460e49c7b2fSDavid Howells op->store.last = last; 461e49c7b2fSDavid Howells op->store.first_offset = offset; 462e49c7b2fSDavid Howells op->store.last_to = to; 463d383e346SDavid Howells op->store.laundering = laundering; 464b3597945SDavid Howells op->mtime = vnode->vfs_inode.i_mtime; 465811f04baSDavid Howells op->flags |= AFS_OPERATION_UNINTR; 466e49c7b2fSDavid Howells op->ops = &afs_store_data_operation; 467e49c7b2fSDavid Howells 468e49c7b2fSDavid Howells try_next_key: 469e49c7b2fSDavid Howells afs_begin_vnode_operation(op); 470e49c7b2fSDavid Howells afs_wait_for_operation(op); 471e49c7b2fSDavid Howells 472e49c7b2fSDavid Howells switch (op->error) { 4734343d008SDavid Howells case -EACCES: 4744343d008SDavid Howells case -EPERM: 4754343d008SDavid Howells case -ENOKEY: 4764343d008SDavid Howells case -EKEYEXPIRED: 4774343d008SDavid Howells case -EKEYREJECTED: 4784343d008SDavid Howells case -EKEYREVOKED: 4794343d008SDavid Howells _debug("next"); 480e49c7b2fSDavid Howells 481e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 482e49c7b2fSDavid Howells if (ret == 0) { 483e49c7b2fSDavid Howells key_put(op->key); 484e49c7b2fSDavid Howells op->key = key_get(wbk->key); 4854343d008SDavid Howells goto try_next_key; 4864343d008SDavid Howells } 487e49c7b2fSDavid Howells break; 488e49c7b2fSDavid Howells } 4894343d008SDavid Howells 4904343d008SDavid Howells afs_put_wb_key(wbk); 491e49c7b2fSDavid Howells _leave(" = %d", op->error); 492e49c7b2fSDavid Howells return afs_put_operation(op); 493d2ddc776SDavid Howells } 494d2ddc776SDavid Howells 495d2ddc776SDavid Howells /* 4964343d008SDavid Howells * Synchronously write back the locked page and any subsequent non-locked dirty 4974343d008SDavid Howells * pages. 49831143d5dSDavid Howells */ 4994343d008SDavid Howells static int afs_write_back_from_locked_page(struct address_space *mapping, 5004343d008SDavid Howells struct writeback_control *wbc, 5014343d008SDavid Howells struct page *primary_page, 5024343d008SDavid Howells pgoff_t final_page) 50331143d5dSDavid Howells { 50413524ab3SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 50531143d5dSDavid Howells struct page *pages[8], *page; 5064343d008SDavid Howells unsigned long count, priv; 5074343d008SDavid Howells unsigned n, offset, to, f, t; 50831143d5dSDavid Howells pgoff_t start, first, last; 509793fe82eSDavid Howells loff_t i_size, end; 51031143d5dSDavid Howells int loop, ret; 51131143d5dSDavid Howells 51231143d5dSDavid Howells _enter(",%lx", primary_page->index); 51331143d5dSDavid Howells 51431143d5dSDavid Howells count = 1; 51531143d5dSDavid Howells if (test_set_page_writeback(primary_page)) 51631143d5dSDavid Howells BUG(); 51731143d5dSDavid Howells 5184343d008SDavid Howells /* Find all consecutive lockable dirty pages that have contiguous 5194343d008SDavid Howells * written regions, stopping when we find a page that is not 5204343d008SDavid Howells * immediately lockable, is not dirty or is missing, or we reach the 5214343d008SDavid Howells * end of the range. 5224343d008SDavid Howells */ 52331143d5dSDavid Howells start = primary_page->index; 5244343d008SDavid Howells priv = page_private(primary_page); 5254343d008SDavid Howells offset = priv & AFS_PRIV_MAX; 5264343d008SDavid Howells to = priv >> AFS_PRIV_SHIFT; 52713524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("store"), 52813524ab3SDavid Howells primary_page->index, priv); 5294343d008SDavid Howells 5304343d008SDavid Howells WARN_ON(offset == to); 53113524ab3SDavid Howells if (offset == to) 53213524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("WARN"), 53313524ab3SDavid Howells primary_page->index, priv); 5344343d008SDavid Howells 5355a813276SDavid Howells if (start >= final_page || 5365a813276SDavid Howells (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))) 53731143d5dSDavid Howells goto no_more; 5384343d008SDavid Howells 53931143d5dSDavid Howells start++; 54031143d5dSDavid Howells do { 54131143d5dSDavid Howells _debug("more %lx [%lx]", start, count); 5424343d008SDavid Howells n = final_page - start + 1; 54331143d5dSDavid Howells if (n > ARRAY_SIZE(pages)) 54431143d5dSDavid Howells n = ARRAY_SIZE(pages); 5454343d008SDavid Howells n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages); 54631143d5dSDavid Howells _debug("fgpc %u", n); 54731143d5dSDavid Howells if (n == 0) 54831143d5dSDavid Howells goto no_more; 54931143d5dSDavid Howells if (pages[0]->index != start) { 5509d577b6aSDavid Howells do { 5519d577b6aSDavid Howells put_page(pages[--n]); 5529d577b6aSDavid Howells } while (n > 0); 55331143d5dSDavid Howells goto no_more; 55431143d5dSDavid Howells } 55531143d5dSDavid Howells 55631143d5dSDavid Howells for (loop = 0; loop < n; loop++) { 55731143d5dSDavid Howells page = pages[loop]; 5585a813276SDavid Howells if (to != PAGE_SIZE && 5595a813276SDavid Howells !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) 5605a813276SDavid Howells break; 5614343d008SDavid Howells if (page->index > final_page) 56231143d5dSDavid Howells break; 563529ae9aaSNick Piggin if (!trylock_page(page)) 56431143d5dSDavid Howells break; 5654343d008SDavid Howells if (!PageDirty(page) || PageWriteback(page)) { 56631143d5dSDavid Howells unlock_page(page); 56731143d5dSDavid Howells break; 56831143d5dSDavid Howells } 5694343d008SDavid Howells 5704343d008SDavid Howells priv = page_private(page); 5714343d008SDavid Howells f = priv & AFS_PRIV_MAX; 5724343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 5735a813276SDavid Howells if (f != 0 && 5745a813276SDavid Howells !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) { 5754343d008SDavid Howells unlock_page(page); 5764343d008SDavid Howells break; 5774343d008SDavid Howells } 5784343d008SDavid Howells to = t; 5794343d008SDavid Howells 58013524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("store+"), 58113524ab3SDavid Howells page->index, priv); 58213524ab3SDavid Howells 58331143d5dSDavid Howells if (!clear_page_dirty_for_io(page)) 58431143d5dSDavid Howells BUG(); 58531143d5dSDavid Howells if (test_set_page_writeback(page)) 58631143d5dSDavid Howells BUG(); 58731143d5dSDavid Howells unlock_page(page); 58831143d5dSDavid Howells put_page(page); 58931143d5dSDavid Howells } 59031143d5dSDavid Howells count += loop; 59131143d5dSDavid Howells if (loop < n) { 59231143d5dSDavid Howells for (; loop < n; loop++) 59331143d5dSDavid Howells put_page(pages[loop]); 59431143d5dSDavid Howells goto no_more; 59531143d5dSDavid Howells } 59631143d5dSDavid Howells 59731143d5dSDavid Howells start += loop; 5984343d008SDavid Howells } while (start <= final_page && count < 65536); 59931143d5dSDavid Howells 60031143d5dSDavid Howells no_more: 6014343d008SDavid Howells /* We now have a contiguous set of dirty pages, each with writeback 6024343d008SDavid Howells * set; the first page is still locked at this point, but all the rest 6034343d008SDavid Howells * have been unlocked. 6044343d008SDavid Howells */ 6054343d008SDavid Howells unlock_page(primary_page); 6064343d008SDavid Howells 60731143d5dSDavid Howells first = primary_page->index; 60831143d5dSDavid Howells last = first + count - 1; 60931143d5dSDavid Howells 610793fe82eSDavid Howells end = (loff_t)last * PAGE_SIZE + to; 611793fe82eSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 612793fe82eSDavid Howells 61331143d5dSDavid Howells _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); 614793fe82eSDavid Howells if (end > i_size) 615793fe82eSDavid Howells to = i_size & ~PAGE_MASK; 61631143d5dSDavid Howells 617d383e346SDavid Howells ret = afs_store_data(mapping, first, last, offset, to, false); 61831143d5dSDavid Howells switch (ret) { 6194343d008SDavid Howells case 0: 6204343d008SDavid Howells ret = count; 6214343d008SDavid Howells break; 6224343d008SDavid Howells 6234343d008SDavid Howells default: 6244343d008SDavid Howells pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); 625df561f66SGustavo A. R. Silva fallthrough; 6264343d008SDavid Howells case -EACCES: 6274343d008SDavid Howells case -EPERM: 6284343d008SDavid Howells case -ENOKEY: 6294343d008SDavid Howells case -EKEYEXPIRED: 6304343d008SDavid Howells case -EKEYREJECTED: 6314343d008SDavid Howells case -EKEYREVOKED: 6324343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 6334343d008SDavid Howells mapping_set_error(mapping, ret); 6344343d008SDavid Howells break; 6354343d008SDavid Howells 63631143d5dSDavid Howells case -EDQUOT: 63731143d5dSDavid Howells case -ENOSPC: 6384343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 6394343d008SDavid Howells mapping_set_error(mapping, -ENOSPC); 64031143d5dSDavid Howells break; 6414343d008SDavid Howells 64231143d5dSDavid Howells case -EROFS: 64331143d5dSDavid Howells case -EIO: 64431143d5dSDavid Howells case -EREMOTEIO: 64531143d5dSDavid Howells case -EFBIG: 64631143d5dSDavid Howells case -ENOENT: 64731143d5dSDavid Howells case -ENOMEDIUM: 64831143d5dSDavid Howells case -ENXIO: 649f51375cdSDavid Howells trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail); 6504343d008SDavid Howells afs_kill_pages(mapping, first, last); 6514343d008SDavid Howells mapping_set_error(mapping, ret); 65231143d5dSDavid Howells break; 65331143d5dSDavid Howells } 65431143d5dSDavid Howells 65531143d5dSDavid Howells _leave(" = %d", ret); 65631143d5dSDavid Howells return ret; 65731143d5dSDavid Howells } 65831143d5dSDavid Howells 65931143d5dSDavid Howells /* 66031143d5dSDavid Howells * write a page back to the server 66131143d5dSDavid Howells * - the caller locked the page for us 66231143d5dSDavid Howells */ 66331143d5dSDavid Howells int afs_writepage(struct page *page, struct writeback_control *wbc) 66431143d5dSDavid Howells { 66531143d5dSDavid Howells int ret; 66631143d5dSDavid Howells 66731143d5dSDavid Howells _enter("{%lx},", page->index); 66831143d5dSDavid Howells 6694343d008SDavid Howells ret = afs_write_back_from_locked_page(page->mapping, wbc, page, 6704343d008SDavid Howells wbc->range_end >> PAGE_SHIFT); 67131143d5dSDavid Howells if (ret < 0) { 67231143d5dSDavid Howells _leave(" = %d", ret); 67331143d5dSDavid Howells return 0; 67431143d5dSDavid Howells } 67531143d5dSDavid Howells 67631143d5dSDavid Howells wbc->nr_to_write -= ret; 67731143d5dSDavid Howells 67831143d5dSDavid Howells _leave(" = 0"); 67931143d5dSDavid Howells return 0; 68031143d5dSDavid Howells } 68131143d5dSDavid Howells 68231143d5dSDavid Howells /* 68331143d5dSDavid Howells * write a region of pages back to the server 68431143d5dSDavid Howells */ 685c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping, 68631143d5dSDavid Howells struct writeback_control *wbc, 68731143d5dSDavid Howells pgoff_t index, pgoff_t end, pgoff_t *_next) 68831143d5dSDavid Howells { 68931143d5dSDavid Howells struct page *page; 69031143d5dSDavid Howells int ret, n; 69131143d5dSDavid Howells 69231143d5dSDavid Howells _enter(",,%lx,%lx,", index, end); 69331143d5dSDavid Howells 69431143d5dSDavid Howells do { 695aef6e415SJan Kara n = find_get_pages_range_tag(mapping, &index, end, 696aef6e415SJan Kara PAGECACHE_TAG_DIRTY, 1, &page); 69731143d5dSDavid Howells if (!n) 69831143d5dSDavid Howells break; 69931143d5dSDavid Howells 70031143d5dSDavid Howells _debug("wback %lx", page->index); 70131143d5dSDavid Howells 702b93b0163SMatthew Wilcox /* 703b93b0163SMatthew Wilcox * at this point we hold neither the i_pages lock nor the 704b93b0163SMatthew Wilcox * page lock: the page may be truncated or invalidated 705b93b0163SMatthew Wilcox * (changing page->mapping to NULL), or even swizzled 706b93b0163SMatthew Wilcox * back from swapper_space to tmpfs file mapping 70731143d5dSDavid Howells */ 7084343d008SDavid Howells ret = lock_page_killable(page); 7094343d008SDavid Howells if (ret < 0) { 7104343d008SDavid Howells put_page(page); 7114343d008SDavid Howells _leave(" = %d", ret); 7124343d008SDavid Howells return ret; 7134343d008SDavid Howells } 71431143d5dSDavid Howells 715c5051c7bSDavid Howells if (page->mapping != mapping || !PageDirty(page)) { 71631143d5dSDavid Howells unlock_page(page); 71709cbfeafSKirill A. Shutemov put_page(page); 71831143d5dSDavid Howells continue; 71931143d5dSDavid Howells } 72031143d5dSDavid Howells 721c5051c7bSDavid Howells if (PageWriteback(page)) { 722c5051c7bSDavid Howells unlock_page(page); 72331143d5dSDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) 72431143d5dSDavid Howells wait_on_page_writeback(page); 72529c8bbbdSDavid Howells put_page(page); 72631143d5dSDavid Howells continue; 72731143d5dSDavid Howells } 72831143d5dSDavid Howells 72965a15109SDavid Howells if (!clear_page_dirty_for_io(page)) 73065a15109SDavid Howells BUG(); 7314343d008SDavid Howells ret = afs_write_back_from_locked_page(mapping, wbc, page, end); 73209cbfeafSKirill A. Shutemov put_page(page); 73331143d5dSDavid Howells if (ret < 0) { 73431143d5dSDavid Howells _leave(" = %d", ret); 73531143d5dSDavid Howells return ret; 73631143d5dSDavid Howells } 73731143d5dSDavid Howells 73831143d5dSDavid Howells wbc->nr_to_write -= ret; 73931143d5dSDavid Howells 74031143d5dSDavid Howells cond_resched(); 74131143d5dSDavid Howells } while (index < end && wbc->nr_to_write > 0); 74231143d5dSDavid Howells 74331143d5dSDavid Howells *_next = index; 74431143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 74531143d5dSDavid Howells return 0; 74631143d5dSDavid Howells } 74731143d5dSDavid Howells 74831143d5dSDavid Howells /* 74931143d5dSDavid Howells * write some of the pending data back to the server 75031143d5dSDavid Howells */ 75131143d5dSDavid Howells int afs_writepages(struct address_space *mapping, 75231143d5dSDavid Howells struct writeback_control *wbc) 75331143d5dSDavid Howells { 754ec0fa0b6SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 75531143d5dSDavid Howells pgoff_t start, end, next; 75631143d5dSDavid Howells int ret; 75731143d5dSDavid Howells 75831143d5dSDavid Howells _enter(""); 75931143d5dSDavid Howells 760ec0fa0b6SDavid Howells /* We have to be careful as we can end up racing with setattr() 761ec0fa0b6SDavid Howells * truncating the pagecache since the caller doesn't take a lock here 762ec0fa0b6SDavid Howells * to prevent it. 763ec0fa0b6SDavid Howells */ 764ec0fa0b6SDavid Howells if (wbc->sync_mode == WB_SYNC_ALL) 765ec0fa0b6SDavid Howells down_read(&vnode->validate_lock); 766ec0fa0b6SDavid Howells else if (!down_read_trylock(&vnode->validate_lock)) 767ec0fa0b6SDavid Howells return 0; 768ec0fa0b6SDavid Howells 76931143d5dSDavid Howells if (wbc->range_cyclic) { 77031143d5dSDavid Howells start = mapping->writeback_index; 77131143d5dSDavid Howells end = -1; 77231143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 7731b430beeSWu Fengguang if (start > 0 && wbc->nr_to_write > 0 && ret == 0) 77431143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, start, 77531143d5dSDavid Howells &next); 77631143d5dSDavid Howells mapping->writeback_index = next; 77731143d5dSDavid Howells } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { 77809cbfeafSKirill A. Shutemov end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT); 77931143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, end, &next); 78031143d5dSDavid Howells if (wbc->nr_to_write > 0) 78131143d5dSDavid Howells mapping->writeback_index = next; 78231143d5dSDavid Howells } else { 78309cbfeafSKirill A. Shutemov start = wbc->range_start >> PAGE_SHIFT; 78409cbfeafSKirill A. Shutemov end = wbc->range_end >> PAGE_SHIFT; 78531143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 78631143d5dSDavid Howells } 78731143d5dSDavid Howells 788ec0fa0b6SDavid Howells up_read(&vnode->validate_lock); 78931143d5dSDavid Howells _leave(" = %d", ret); 79031143d5dSDavid Howells return ret; 79131143d5dSDavid Howells } 79231143d5dSDavid Howells 79331143d5dSDavid Howells /* 79431143d5dSDavid Howells * write to an AFS file 79531143d5dSDavid Howells */ 79650b5551dSAl Viro ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) 79731143d5dSDavid Howells { 798496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); 79931143d5dSDavid Howells ssize_t result; 80050b5551dSAl Viro size_t count = iov_iter_count(from); 80131143d5dSDavid Howells 8023b6492dfSDavid Howells _enter("{%llx:%llu},{%zu},", 80350b5551dSAl Viro vnode->fid.vid, vnode->fid.vnode, count); 80431143d5dSDavid Howells 80531143d5dSDavid Howells if (IS_SWAPFILE(&vnode->vfs_inode)) { 80631143d5dSDavid Howells printk(KERN_INFO 80731143d5dSDavid Howells "AFS: Attempt to write to active swap file!\n"); 80831143d5dSDavid Howells return -EBUSY; 80931143d5dSDavid Howells } 81031143d5dSDavid Howells 81131143d5dSDavid Howells if (!count) 81231143d5dSDavid Howells return 0; 81331143d5dSDavid Howells 81450b5551dSAl Viro result = generic_file_write_iter(iocb, from); 81531143d5dSDavid Howells 81631143d5dSDavid Howells _leave(" = %zd", result); 81731143d5dSDavid Howells return result; 81831143d5dSDavid Howells } 81931143d5dSDavid Howells 82031143d5dSDavid Howells /* 82131143d5dSDavid Howells * flush any dirty pages for this process, and check for write errors. 82231143d5dSDavid Howells * - the return status from this call provides a reliable indication of 82331143d5dSDavid Howells * whether any write errors occurred for this process. 82431143d5dSDavid Howells */ 82502c24a82SJosef Bacik int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 82631143d5dSDavid Howells { 8273c981bfcSAl Viro struct inode *inode = file_inode(file); 8283c981bfcSAl Viro struct afs_vnode *vnode = AFS_FS_I(inode); 82931143d5dSDavid Howells 8303b6492dfSDavid Howells _enter("{%llx:%llu},{n=%pD},%d", 8313c981bfcSAl Viro vnode->fid.vid, vnode->fid.vnode, file, 83231143d5dSDavid Howells datasync); 83331143d5dSDavid Howells 8344343d008SDavid Howells return file_write_and_wait_range(file, start, end); 83531143d5dSDavid Howells } 8369b3f26c9SDavid Howells 8379b3f26c9SDavid Howells /* 8389b3f26c9SDavid Howells * notification that a previously read-only page is about to become writable 8399b3f26c9SDavid Howells * - if it returns an error, the caller will deliver a bus error signal 8409b3f26c9SDavid Howells */ 8410722f186SSouptick Joarder vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) 8429b3f26c9SDavid Howells { 8431cf7a151SDavid Howells struct file *file = vmf->vma->vm_file; 8441cf7a151SDavid Howells struct inode *inode = file_inode(file); 8451cf7a151SDavid Howells struct afs_vnode *vnode = AFS_FS_I(inode); 8461cf7a151SDavid Howells unsigned long priv; 8479b3f26c9SDavid Howells 8483b6492dfSDavid Howells _enter("{{%llx:%llu}},{%lx}", 8491cf7a151SDavid Howells vnode->fid.vid, vnode->fid.vnode, vmf->page->index); 8509b3f26c9SDavid Howells 8511cf7a151SDavid Howells sb_start_pagefault(inode->i_sb); 8521cf7a151SDavid Howells 8531cf7a151SDavid Howells /* Wait for the page to be written to the cache before we allow it to 8541cf7a151SDavid Howells * be modified. We then assume the entire page will need writing back. 8551cf7a151SDavid Howells */ 8569b3f26c9SDavid Howells #ifdef CONFIG_AFS_FSCACHE 8571cf7a151SDavid Howells fscache_wait_on_page_write(vnode->cache, vmf->page); 8589b3f26c9SDavid Howells #endif 8599b3f26c9SDavid Howells 8601cf7a151SDavid Howells if (PageWriteback(vmf->page) && 8611cf7a151SDavid Howells wait_on_page_bit_killable(vmf->page, PG_writeback) < 0) 8621cf7a151SDavid Howells return VM_FAULT_RETRY; 8631cf7a151SDavid Howells 8641cf7a151SDavid Howells if (lock_page_killable(vmf->page) < 0) 8651cf7a151SDavid Howells return VM_FAULT_RETRY; 8661cf7a151SDavid Howells 8671cf7a151SDavid Howells /* We mustn't change page->private until writeback is complete as that 8681cf7a151SDavid Howells * details the portion of the page we need to write back and we might 8691cf7a151SDavid Howells * need to redirty the page if there's a problem. 8701cf7a151SDavid Howells */ 8711cf7a151SDavid Howells wait_on_page_writeback(vmf->page); 8721cf7a151SDavid Howells 8731cf7a151SDavid Howells priv = (unsigned long)PAGE_SIZE << AFS_PRIV_SHIFT; /* To */ 8741cf7a151SDavid Howells priv |= 0; /* From */ 87513524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"), 87613524ab3SDavid Howells vmf->page->index, priv); 877fa04a40bSDavid Howells if (PagePrivate(vmf->page)) 8781cf7a151SDavid Howells set_page_private(vmf->page, priv); 879fa04a40bSDavid Howells else 880fa04a40bSDavid Howells attach_page_private(vmf->page, (void *)priv); 881bb413489SDavid Howells file_update_time(file); 8821cf7a151SDavid Howells 8831cf7a151SDavid Howells sb_end_pagefault(inode->i_sb); 8841cf7a151SDavid Howells return VM_FAULT_LOCKED; 8859b3f26c9SDavid Howells } 8864343d008SDavid Howells 8874343d008SDavid Howells /* 8884343d008SDavid Howells * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. 8894343d008SDavid Howells */ 8904343d008SDavid Howells void afs_prune_wb_keys(struct afs_vnode *vnode) 8914343d008SDavid Howells { 8924343d008SDavid Howells LIST_HEAD(graveyard); 8934343d008SDavid Howells struct afs_wb_key *wbk, *tmp; 8944343d008SDavid Howells 8954343d008SDavid Howells /* Discard unused keys */ 8964343d008SDavid Howells spin_lock(&vnode->wb_lock); 8974343d008SDavid Howells 8984343d008SDavid Howells if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && 8994343d008SDavid Howells !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { 9004343d008SDavid Howells list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { 9014343d008SDavid Howells if (refcount_read(&wbk->usage) == 1) 9024343d008SDavid Howells list_move(&wbk->vnode_link, &graveyard); 9034343d008SDavid Howells } 9044343d008SDavid Howells } 9054343d008SDavid Howells 9064343d008SDavid Howells spin_unlock(&vnode->wb_lock); 9074343d008SDavid Howells 9084343d008SDavid Howells while (!list_empty(&graveyard)) { 9094343d008SDavid Howells wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); 9104343d008SDavid Howells list_del(&wbk->vnode_link); 9114343d008SDavid Howells afs_put_wb_key(wbk); 9124343d008SDavid Howells } 9134343d008SDavid Howells } 9144343d008SDavid Howells 9154343d008SDavid Howells /* 9164343d008SDavid Howells * Clean up a page during invalidation. 9174343d008SDavid Howells */ 9184343d008SDavid Howells int afs_launder_page(struct page *page) 9194343d008SDavid Howells { 9204343d008SDavid Howells struct address_space *mapping = page->mapping; 9214343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 9224343d008SDavid Howells unsigned long priv; 9234343d008SDavid Howells unsigned int f, t; 9244343d008SDavid Howells int ret = 0; 9254343d008SDavid Howells 9264343d008SDavid Howells _enter("{%lx}", page->index); 9274343d008SDavid Howells 9284343d008SDavid Howells priv = page_private(page); 9294343d008SDavid Howells if (clear_page_dirty_for_io(page)) { 9304343d008SDavid Howells f = 0; 9314343d008SDavid Howells t = PAGE_SIZE; 9324343d008SDavid Howells if (PagePrivate(page)) { 9334343d008SDavid Howells f = priv & AFS_PRIV_MAX; 9344343d008SDavid Howells t = priv >> AFS_PRIV_SHIFT; 9354343d008SDavid Howells } 9364343d008SDavid Howells 93713524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("launder"), 93813524ab3SDavid Howells page->index, priv); 939d383e346SDavid Howells ret = afs_store_data(mapping, page->index, page->index, t, f, true); 9404343d008SDavid Howells } 9414343d008SDavid Howells 942fa04a40bSDavid Howells priv = (unsigned long)detach_page_private(page); 94313524ab3SDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("laundered"), 94413524ab3SDavid Howells page->index, priv); 9454343d008SDavid Howells 9464343d008SDavid Howells #ifdef CONFIG_AFS_FSCACHE 9474343d008SDavid Howells if (PageFsCache(page)) { 9484343d008SDavid Howells fscache_wait_on_page_write(vnode->cache, page); 9494343d008SDavid Howells fscache_uncache_page(vnode->cache, page); 9504343d008SDavid Howells } 9514343d008SDavid Howells #endif 9524343d008SDavid Howells return ret; 95331143d5dSDavid Howells } 954