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 /* 26*c4508464SDavid Howells * Handle completion of a read operation to fill a page. 27*c4508464SDavid Howells */ 28*c4508464SDavid Howells static void afs_fill_hole(struct afs_read *req) 29*c4508464SDavid Howells { 30*c4508464SDavid Howells if (iov_iter_count(req->iter) > 0) 31*c4508464SDavid Howells /* The read was short - clear the excess buffer. */ 32*c4508464SDavid Howells iov_iter_zero(iov_iter_count(req->iter), req->iter); 33*c4508464SDavid Howells } 34*c4508464SDavid Howells 35*c4508464SDavid Howells /* 3631143d5dSDavid Howells * partly or wholly fill a page that's under preparation for writing 3731143d5dSDavid Howells */ 38c69bf479SDavid Howells static int afs_fill_page(struct file *file, 39e8e581a8SDavid Howells loff_t pos, unsigned int len, struct page *page) 4031143d5dSDavid Howells { 41c69bf479SDavid Howells struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 42196ee9cdSDavid Howells struct afs_read *req; 432a0b4f64SDavid Howells size_t p; 442a0b4f64SDavid Howells void *data; 4531143d5dSDavid Howells int ret; 4631143d5dSDavid Howells 475e7f2337SAnton Blanchard _enter(",,%llu", (unsigned long long)pos); 4831143d5dSDavid Howells 492a0b4f64SDavid Howells if (pos >= vnode->vfs_inode.i_size) { 502a0b4f64SDavid Howells p = pos & ~PAGE_MASK; 512a0b4f64SDavid Howells ASSERTCMP(p + len, <=, PAGE_SIZE); 522a0b4f64SDavid Howells data = kmap(page); 532a0b4f64SDavid Howells memset(data + p, 0, len); 542a0b4f64SDavid Howells kunmap(page); 552a0b4f64SDavid Howells return 0; 562a0b4f64SDavid Howells } 572a0b4f64SDavid Howells 58*c4508464SDavid Howells req = kzalloc(sizeof(struct afs_read), GFP_KERNEL); 59196ee9cdSDavid Howells if (!req) 60196ee9cdSDavid Howells return -ENOMEM; 61196ee9cdSDavid Howells 62f3ddee8dSDavid Howells refcount_set(&req->usage, 1); 63*c4508464SDavid Howells req->vnode = vnode; 64*c4508464SDavid Howells req->done = afs_fill_hole; 65c69bf479SDavid Howells req->key = key_get(afs_file_key(file)); 66196ee9cdSDavid Howells req->pos = pos; 67e8e581a8SDavid Howells req->len = len; 68196ee9cdSDavid Howells req->nr_pages = 1; 69*c4508464SDavid Howells req->iter = &req->def_iter; 70*c4508464SDavid Howells iov_iter_xarray(&req->def_iter, READ, &file->f_mapping->i_pages, pos, len); 71196ee9cdSDavid Howells 72c69bf479SDavid Howells ret = afs_fetch_data(vnode, req); 73196ee9cdSDavid Howells afs_put_read(req); 7431143d5dSDavid Howells if (ret < 0) { 7531143d5dSDavid Howells if (ret == -ENOENT) { 7631143d5dSDavid Howells _debug("got NOENT from server" 7731143d5dSDavid Howells " - marking file deleted and stale"); 7831143d5dSDavid Howells set_bit(AFS_VNODE_DELETED, &vnode->flags); 7931143d5dSDavid Howells ret = -ESTALE; 8031143d5dSDavid Howells } 8131143d5dSDavid Howells } 8231143d5dSDavid Howells 8331143d5dSDavid Howells _leave(" = %d", ret); 8431143d5dSDavid Howells return ret; 8531143d5dSDavid Howells } 8631143d5dSDavid Howells 8731143d5dSDavid Howells /* 8831143d5dSDavid Howells * prepare to perform part of a write to a page 8931143d5dSDavid Howells */ 9015b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping, 9115b4650eSNick Piggin loff_t pos, unsigned len, unsigned flags, 9221db2cdcSDavid Howells struct page **_page, void **fsdata) 9331143d5dSDavid Howells { 94496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 9515b4650eSNick Piggin struct page *page; 964343d008SDavid Howells unsigned long priv; 974343d008SDavid Howells unsigned f, from = pos & (PAGE_SIZE - 1); 984343d008SDavid Howells unsigned t, to = from + len; 9909cbfeafSKirill A. Shutemov pgoff_t index = pos >> PAGE_SHIFT; 10031143d5dSDavid Howells int ret; 10131143d5dSDavid Howells 1023b6492dfSDavid Howells _enter("{%llx:%llu},{%lx},%u,%u", 10315b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, index, from, to); 10431143d5dSDavid Howells 10554566b2cSNick Piggin page = grab_cache_page_write_begin(mapping, index, flags); 1064343d008SDavid Howells if (!page) 10715b4650eSNick Piggin return -ENOMEM; 10815b4650eSNick Piggin 10909cbfeafSKirill A. Shutemov if (!PageUptodate(page) && len != PAGE_SIZE) { 110c69bf479SDavid Howells ret = afs_fill_page(file, pos & PAGE_MASK, PAGE_SIZE, page); 11131143d5dSDavid Howells if (ret < 0) { 1126d06b0d2SDavid Howells unlock_page(page); 1136d06b0d2SDavid Howells put_page(page); 11431143d5dSDavid Howells _leave(" = %d [prep]", ret); 11531143d5dSDavid Howells return ret; 11631143d5dSDavid Howells } 11715b4650eSNick Piggin SetPageUptodate(page); 11831143d5dSDavid Howells } 11931143d5dSDavid Howells 12031143d5dSDavid Howells try_again: 1214343d008SDavid Howells /* See if this page is already partially written in a way that we can 1224343d008SDavid Howells * merge the new write with. 1234343d008SDavid Howells */ 1244343d008SDavid Howells t = f = 0; 1254343d008SDavid Howells if (PagePrivate(page)) { 1264343d008SDavid Howells priv = page_private(page); 12767d78a6fSDavid Howells f = afs_page_dirty_from(page, priv); 12867d78a6fSDavid Howells t = afs_page_dirty_to(page, priv); 1294343d008SDavid Howells ASSERTCMP(f, <=, t); 13031143d5dSDavid Howells } 13131143d5dSDavid Howells 1324343d008SDavid Howells if (f != t) { 1335a039c32SDavid Howells if (PageWriteback(page)) { 13467d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("alrdy"), page); 1355a039c32SDavid Howells goto flush_conflicting_write; 1365a039c32SDavid Howells } 1375a813276SDavid Howells /* If the file is being filled locally, allow inter-write 1385a813276SDavid Howells * spaces to be merged into writes. If it's not, only write 1395a813276SDavid Howells * back what the user gives us. 1405a813276SDavid Howells */ 1415a813276SDavid Howells if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) && 1425a813276SDavid Howells (to < f || from > t)) 1434343d008SDavid Howells goto flush_conflicting_write; 14431143d5dSDavid Howells } 14531143d5dSDavid Howells 14621db2cdcSDavid Howells *_page = page; 1474343d008SDavid Howells _leave(" = 0"); 14831143d5dSDavid Howells return 0; 14931143d5dSDavid Howells 1504343d008SDavid Howells /* The previous write and this write aren't adjacent or overlapping, so 1514343d008SDavid Howells * flush the page out. 1524343d008SDavid Howells */ 1534343d008SDavid Howells flush_conflicting_write: 15431143d5dSDavid Howells _debug("flush conflict"); 1554343d008SDavid Howells ret = write_one_page(page); 15621db2cdcSDavid Howells if (ret < 0) 15721db2cdcSDavid Howells goto error; 15831143d5dSDavid Howells 1594343d008SDavid Howells ret = lock_page_killable(page); 16021db2cdcSDavid Howells if (ret < 0) 16121db2cdcSDavid Howells goto error; 16221db2cdcSDavid Howells goto try_again; 16321db2cdcSDavid Howells 16421db2cdcSDavid Howells error: 16521db2cdcSDavid Howells put_page(page); 1664343d008SDavid Howells _leave(" = %d", ret); 1674343d008SDavid Howells return ret; 1684343d008SDavid Howells } 16931143d5dSDavid Howells 17031143d5dSDavid Howells /* 17131143d5dSDavid Howells * finalise part of a write to a page 17231143d5dSDavid Howells */ 17315b4650eSNick Piggin int afs_write_end(struct file *file, struct address_space *mapping, 17415b4650eSNick Piggin loff_t pos, unsigned len, unsigned copied, 17515b4650eSNick Piggin struct page *page, void *fsdata) 17631143d5dSDavid Howells { 177496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 178f792e3acSDavid Howells unsigned long priv; 179f792e3acSDavid Howells unsigned int f, from = pos & (PAGE_SIZE - 1); 180f792e3acSDavid Howells unsigned int t, to = from + copied; 18131143d5dSDavid Howells loff_t i_size, maybe_i_size; 1823ad216eeSDavid Howells int ret = 0; 18331143d5dSDavid Howells 1843b6492dfSDavid Howells _enter("{%llx:%llu},{%lx}", 18515b4650eSNick Piggin vnode->fid.vid, vnode->fid.vnode, page->index); 18631143d5dSDavid Howells 1873ad216eeSDavid Howells if (copied == 0) 1883ad216eeSDavid Howells goto out; 1893ad216eeSDavid Howells 19015b4650eSNick Piggin maybe_i_size = pos + copied; 19131143d5dSDavid Howells 19231143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 19331143d5dSDavid Howells if (maybe_i_size > i_size) { 1941f32ef79SDavid Howells write_seqlock(&vnode->cb_lock); 19531143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 19631143d5dSDavid Howells if (maybe_i_size > i_size) 19731143d5dSDavid Howells i_size_write(&vnode->vfs_inode, maybe_i_size); 1981f32ef79SDavid Howells write_sequnlock(&vnode->cb_lock); 19931143d5dSDavid Howells } 20031143d5dSDavid Howells 201e8e581a8SDavid Howells if (!PageUptodate(page)) { 202e8e581a8SDavid Howells if (copied < len) { 203e8e581a8SDavid Howells /* Try and load any missing data from the server. The 204e8e581a8SDavid Howells * unmarshalling routine will take care of clearing any 205e8e581a8SDavid Howells * bits that are beyond the EOF. 206e8e581a8SDavid Howells */ 207c69bf479SDavid Howells ret = afs_fill_page(file, pos + copied, 208e8e581a8SDavid Howells len - copied, page); 209e8e581a8SDavid Howells if (ret < 0) 210afae457dSDavid Howells goto out; 211e8e581a8SDavid Howells } 212e8e581a8SDavid Howells SetPageUptodate(page); 213e8e581a8SDavid Howells } 214e8e581a8SDavid Howells 215f792e3acSDavid Howells if (PagePrivate(page)) { 216f792e3acSDavid Howells priv = page_private(page); 21767d78a6fSDavid Howells f = afs_page_dirty_from(page, priv); 21867d78a6fSDavid Howells t = afs_page_dirty_to(page, priv); 219f792e3acSDavid Howells if (from < f) 220f792e3acSDavid Howells f = from; 221f792e3acSDavid Howells if (to > t) 222f792e3acSDavid Howells t = to; 22367d78a6fSDavid Howells priv = afs_page_dirty(page, f, t); 224f792e3acSDavid Howells set_page_private(page, priv); 22567d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("dirty+"), page); 226f792e3acSDavid Howells } else { 22767d78a6fSDavid Howells priv = afs_page_dirty(page, from, to); 228f792e3acSDavid Howells attach_page_private(page, (void *)priv); 22967d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("dirty"), page); 230f792e3acSDavid Howells } 231f792e3acSDavid Howells 23231143d5dSDavid Howells set_page_dirty(page); 23331143d5dSDavid Howells if (PageDirty(page)) 23431143d5dSDavid Howells _debug("dirtied"); 235afae457dSDavid Howells ret = copied; 236afae457dSDavid Howells 237afae457dSDavid Howells out: 23815b4650eSNick Piggin unlock_page(page); 23909cbfeafSKirill A. Shutemov put_page(page); 240afae457dSDavid Howells return ret; 24131143d5dSDavid Howells } 24231143d5dSDavid Howells 24331143d5dSDavid Howells /* 24431143d5dSDavid Howells * kill all the pages in the given range 24531143d5dSDavid Howells */ 2464343d008SDavid Howells static void afs_kill_pages(struct address_space *mapping, 24731143d5dSDavid Howells pgoff_t first, pgoff_t last) 24831143d5dSDavid Howells { 2494343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 25031143d5dSDavid Howells struct pagevec pv; 25131143d5dSDavid Howells unsigned count, loop; 25231143d5dSDavid Howells 2533b6492dfSDavid Howells _enter("{%llx:%llu},%lx-%lx", 25431143d5dSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 25531143d5dSDavid Howells 25686679820SMel Gorman pagevec_init(&pv); 25731143d5dSDavid Howells 25831143d5dSDavid Howells do { 25931143d5dSDavid Howells _debug("kill %lx-%lx", first, last); 26031143d5dSDavid Howells 26131143d5dSDavid Howells count = last - first + 1; 26231143d5dSDavid Howells if (count > PAGEVEC_SIZE) 26331143d5dSDavid Howells count = PAGEVEC_SIZE; 2644343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 26531143d5dSDavid Howells ASSERTCMP(pv.nr, ==, count); 26631143d5dSDavid Howells 26731143d5dSDavid Howells for (loop = 0; loop < count; loop++) { 2687286a35eSDavid Howells struct page *page = pv.pages[loop]; 2697286a35eSDavid Howells ClearPageUptodate(page); 2707286a35eSDavid Howells SetPageError(page); 2714343d008SDavid Howells end_page_writeback(page); 2724343d008SDavid Howells if (page->index >= first) 2734343d008SDavid Howells first = page->index + 1; 2744343d008SDavid Howells lock_page(page); 2754343d008SDavid Howells generic_error_remove_page(mapping, page); 27621bd68f1SMarc Dionne unlock_page(page); 2774343d008SDavid Howells } 2784343d008SDavid Howells 2794343d008SDavid Howells __pagevec_release(&pv); 2804343d008SDavid Howells } while (first <= last); 2814343d008SDavid Howells 2824343d008SDavid Howells _leave(""); 2834343d008SDavid Howells } 2844343d008SDavid Howells 2854343d008SDavid Howells /* 2864343d008SDavid Howells * Redirty all the pages in a given range. 2874343d008SDavid Howells */ 2884343d008SDavid Howells static void afs_redirty_pages(struct writeback_control *wbc, 2894343d008SDavid Howells struct address_space *mapping, 2904343d008SDavid Howells pgoff_t first, pgoff_t last) 2914343d008SDavid Howells { 2924343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 2934343d008SDavid Howells struct pagevec pv; 2944343d008SDavid Howells unsigned count, loop; 2954343d008SDavid Howells 2963b6492dfSDavid Howells _enter("{%llx:%llu},%lx-%lx", 2974343d008SDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 2984343d008SDavid Howells 299487e2c9fSLinus Torvalds pagevec_init(&pv); 3004343d008SDavid Howells 3014343d008SDavid Howells do { 3024343d008SDavid Howells _debug("redirty %lx-%lx", first, last); 3034343d008SDavid Howells 3044343d008SDavid Howells count = last - first + 1; 3054343d008SDavid Howells if (count > PAGEVEC_SIZE) 3064343d008SDavid Howells count = PAGEVEC_SIZE; 3074343d008SDavid Howells pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); 3084343d008SDavid Howells ASSERTCMP(pv.nr, ==, count); 3094343d008SDavid Howells 3104343d008SDavid Howells for (loop = 0; loop < count; loop++) { 3114343d008SDavid Howells struct page *page = pv.pages[loop]; 3124343d008SDavid Howells 3134343d008SDavid Howells redirty_page_for_writepage(wbc, page); 3147286a35eSDavid Howells end_page_writeback(page); 3157286a35eSDavid Howells if (page->index >= first) 3167286a35eSDavid Howells first = page->index + 1; 31731143d5dSDavid Howells } 31831143d5dSDavid Howells 31931143d5dSDavid Howells __pagevec_release(&pv); 3204343d008SDavid Howells } while (first <= last); 32131143d5dSDavid Howells 32231143d5dSDavid Howells _leave(""); 32331143d5dSDavid Howells } 32431143d5dSDavid Howells 32531143d5dSDavid Howells /* 326a58823acSDavid Howells * completion of write to server 327a58823acSDavid Howells */ 328a58823acSDavid Howells static void afs_pages_written_back(struct afs_vnode *vnode, 329a58823acSDavid Howells pgoff_t first, pgoff_t last) 330a58823acSDavid Howells { 331a58823acSDavid Howells struct pagevec pv; 332a58823acSDavid Howells unsigned count, loop; 333a58823acSDavid Howells 334a58823acSDavid Howells _enter("{%llx:%llu},{%lx-%lx}", 335a58823acSDavid Howells vnode->fid.vid, vnode->fid.vnode, first, last); 336a58823acSDavid Howells 337a58823acSDavid Howells pagevec_init(&pv); 338a58823acSDavid Howells 339a58823acSDavid Howells do { 340a58823acSDavid Howells _debug("done %lx-%lx", first, last); 341a58823acSDavid Howells 342a58823acSDavid Howells count = last - first + 1; 343a58823acSDavid Howells if (count > PAGEVEC_SIZE) 344a58823acSDavid Howells count = PAGEVEC_SIZE; 345a58823acSDavid Howells pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, 346a58823acSDavid Howells first, count, pv.pages); 347a58823acSDavid Howells ASSERTCMP(pv.nr, ==, count); 348a58823acSDavid Howells 349a58823acSDavid Howells for (loop = 0; loop < count; loop++) { 35067d78a6fSDavid Howells detach_page_private(pv.pages[loop]); 351a58823acSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("clear"), 35267d78a6fSDavid Howells pv.pages[loop]); 353a58823acSDavid Howells end_page_writeback(pv.pages[loop]); 354a58823acSDavid Howells } 355a58823acSDavid Howells first += count; 356a58823acSDavid Howells __pagevec_release(&pv); 357a58823acSDavid Howells } while (first <= last); 358a58823acSDavid Howells 359a58823acSDavid Howells afs_prune_wb_keys(vnode); 360a58823acSDavid Howells _leave(""); 361a58823acSDavid Howells } 362a58823acSDavid Howells 363a58823acSDavid Howells /* 364e49c7b2fSDavid Howells * Find a key to use for the writeback. We cached the keys used to author the 365e49c7b2fSDavid Howells * writes on the vnode. *_wbk will contain the last writeback key used or NULL 366e49c7b2fSDavid Howells * and we need to start from there if it's set. 367e49c7b2fSDavid Howells */ 368e49c7b2fSDavid Howells static int afs_get_writeback_key(struct afs_vnode *vnode, 369e49c7b2fSDavid Howells struct afs_wb_key **_wbk) 370e49c7b2fSDavid Howells { 371e49c7b2fSDavid Howells struct afs_wb_key *wbk = NULL; 372e49c7b2fSDavid Howells struct list_head *p; 373e49c7b2fSDavid Howells int ret = -ENOKEY, ret2; 374e49c7b2fSDavid Howells 375e49c7b2fSDavid Howells spin_lock(&vnode->wb_lock); 376e49c7b2fSDavid Howells if (*_wbk) 377e49c7b2fSDavid Howells p = (*_wbk)->vnode_link.next; 378e49c7b2fSDavid Howells else 379e49c7b2fSDavid Howells p = vnode->wb_keys.next; 380e49c7b2fSDavid Howells 381e49c7b2fSDavid Howells while (p != &vnode->wb_keys) { 382e49c7b2fSDavid Howells wbk = list_entry(p, struct afs_wb_key, vnode_link); 383e49c7b2fSDavid Howells _debug("wbk %u", key_serial(wbk->key)); 384e49c7b2fSDavid Howells ret2 = key_validate(wbk->key); 385e49c7b2fSDavid Howells if (ret2 == 0) { 386e49c7b2fSDavid Howells refcount_inc(&wbk->usage); 387e49c7b2fSDavid Howells _debug("USE WB KEY %u", key_serial(wbk->key)); 388e49c7b2fSDavid Howells break; 389e49c7b2fSDavid Howells } 390e49c7b2fSDavid Howells 391e49c7b2fSDavid Howells wbk = NULL; 392e49c7b2fSDavid Howells if (ret == -ENOKEY) 393e49c7b2fSDavid Howells ret = ret2; 394e49c7b2fSDavid Howells p = p->next; 395e49c7b2fSDavid Howells } 396e49c7b2fSDavid Howells 397e49c7b2fSDavid Howells spin_unlock(&vnode->wb_lock); 398e49c7b2fSDavid Howells if (*_wbk) 399e49c7b2fSDavid Howells afs_put_wb_key(*_wbk); 400e49c7b2fSDavid Howells *_wbk = wbk; 401e49c7b2fSDavid Howells return 0; 402e49c7b2fSDavid Howells } 403e49c7b2fSDavid Howells 404e49c7b2fSDavid Howells static void afs_store_data_success(struct afs_operation *op) 405e49c7b2fSDavid Howells { 406e49c7b2fSDavid Howells struct afs_vnode *vnode = op->file[0].vnode; 407e49c7b2fSDavid Howells 408da8d0755SDavid Howells op->ctime = op->file[0].scb.status.mtime_client; 409e49c7b2fSDavid Howells afs_vnode_commit_status(op, &op->file[0]); 410e49c7b2fSDavid Howells if (op->error == 0) { 411d383e346SDavid Howells if (!op->store.laundering) 412e49c7b2fSDavid Howells afs_pages_written_back(vnode, op->store.first, op->store.last); 413e49c7b2fSDavid Howells afs_stat_v(vnode, n_stores); 414e49c7b2fSDavid Howells atomic_long_add((op->store.last * PAGE_SIZE + op->store.last_to) - 415e49c7b2fSDavid Howells (op->store.first * PAGE_SIZE + op->store.first_offset), 416e49c7b2fSDavid Howells &afs_v2net(vnode)->n_store_bytes); 417e49c7b2fSDavid Howells } 418e49c7b2fSDavid Howells } 419e49c7b2fSDavid Howells 420e49c7b2fSDavid Howells static const struct afs_operation_ops afs_store_data_operation = { 421e49c7b2fSDavid Howells .issue_afs_rpc = afs_fs_store_data, 422e49c7b2fSDavid Howells .issue_yfs_rpc = yfs_fs_store_data, 423e49c7b2fSDavid Howells .success = afs_store_data_success, 424e49c7b2fSDavid Howells }; 425e49c7b2fSDavid Howells 426e49c7b2fSDavid Howells /* 427d2ddc776SDavid Howells * write to a file 42831143d5dSDavid Howells */ 4294343d008SDavid Howells static int afs_store_data(struct address_space *mapping, 4304343d008SDavid Howells pgoff_t first, pgoff_t last, 431d383e346SDavid Howells unsigned offset, unsigned to, bool laundering) 43231143d5dSDavid Howells { 4334343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 434e49c7b2fSDavid Howells struct afs_operation *op; 4354343d008SDavid Howells struct afs_wb_key *wbk = NULL; 436e49c7b2fSDavid Howells int ret; 437d2ddc776SDavid Howells 4383b6492dfSDavid Howells _enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x", 439d2ddc776SDavid Howells vnode->volume->name, 440d2ddc776SDavid Howells vnode->fid.vid, 441d2ddc776SDavid Howells vnode->fid.vnode, 442d2ddc776SDavid Howells vnode->fid.unique, 443d2ddc776SDavid Howells first, last, offset, to); 444d2ddc776SDavid Howells 445e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 446e49c7b2fSDavid Howells if (ret) { 4474343d008SDavid Howells _leave(" = %d [no keys]", ret); 4484343d008SDavid Howells return ret; 449d2ddc776SDavid Howells } 450d2ddc776SDavid Howells 451e49c7b2fSDavid Howells op = afs_alloc_operation(wbk->key, vnode->volume); 452e49c7b2fSDavid Howells if (IS_ERR(op)) { 453e49c7b2fSDavid Howells afs_put_wb_key(wbk); 454e49c7b2fSDavid Howells return -ENOMEM; 455d2ddc776SDavid Howells } 456d2ddc776SDavid Howells 457e49c7b2fSDavid Howells afs_op_set_vnode(op, 0, vnode); 458e49c7b2fSDavid Howells op->file[0].dv_delta = 1; 459e49c7b2fSDavid Howells op->store.mapping = mapping; 460e49c7b2fSDavid Howells op->store.first = first; 461e49c7b2fSDavid Howells op->store.last = last; 462e49c7b2fSDavid Howells op->store.first_offset = offset; 463e49c7b2fSDavid Howells op->store.last_to = to; 464d383e346SDavid Howells op->store.laundering = laundering; 465b3597945SDavid Howells op->mtime = vnode->vfs_inode.i_mtime; 466811f04baSDavid Howells op->flags |= AFS_OPERATION_UNINTR; 467e49c7b2fSDavid Howells op->ops = &afs_store_data_operation; 468e49c7b2fSDavid Howells 469e49c7b2fSDavid Howells try_next_key: 470e49c7b2fSDavid Howells afs_begin_vnode_operation(op); 471e49c7b2fSDavid Howells afs_wait_for_operation(op); 472e49c7b2fSDavid Howells 473e49c7b2fSDavid Howells switch (op->error) { 4744343d008SDavid Howells case -EACCES: 4754343d008SDavid Howells case -EPERM: 4764343d008SDavid Howells case -ENOKEY: 4774343d008SDavid Howells case -EKEYEXPIRED: 4784343d008SDavid Howells case -EKEYREJECTED: 4794343d008SDavid Howells case -EKEYREVOKED: 4804343d008SDavid Howells _debug("next"); 481e49c7b2fSDavid Howells 482e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 483e49c7b2fSDavid Howells if (ret == 0) { 484e49c7b2fSDavid Howells key_put(op->key); 485e49c7b2fSDavid Howells op->key = key_get(wbk->key); 4864343d008SDavid Howells goto try_next_key; 4874343d008SDavid Howells } 488e49c7b2fSDavid Howells break; 489e49c7b2fSDavid Howells } 4904343d008SDavid Howells 4914343d008SDavid Howells afs_put_wb_key(wbk); 492e49c7b2fSDavid Howells _leave(" = %d", op->error); 493e49c7b2fSDavid Howells return afs_put_operation(op); 494d2ddc776SDavid Howells } 495d2ddc776SDavid Howells 496d2ddc776SDavid Howells /* 4974343d008SDavid Howells * Synchronously write back the locked page and any subsequent non-locked dirty 4984343d008SDavid Howells * pages. 49931143d5dSDavid Howells */ 5004343d008SDavid Howells static int afs_write_back_from_locked_page(struct address_space *mapping, 5014343d008SDavid Howells struct writeback_control *wbc, 5024343d008SDavid Howells struct page *primary_page, 5034343d008SDavid Howells pgoff_t final_page) 50431143d5dSDavid Howells { 50513524ab3SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 50631143d5dSDavid Howells struct page *pages[8], *page; 5074343d008SDavid Howells unsigned long count, priv; 5084343d008SDavid Howells unsigned n, offset, to, f, t; 50931143d5dSDavid Howells pgoff_t start, first, last; 510793fe82eSDavid Howells loff_t i_size, end; 51131143d5dSDavid Howells int loop, ret; 51231143d5dSDavid Howells 51331143d5dSDavid Howells _enter(",%lx", primary_page->index); 51431143d5dSDavid Howells 51531143d5dSDavid Howells count = 1; 51631143d5dSDavid Howells if (test_set_page_writeback(primary_page)) 51731143d5dSDavid Howells BUG(); 51831143d5dSDavid Howells 5194343d008SDavid Howells /* Find all consecutive lockable dirty pages that have contiguous 5204343d008SDavid Howells * written regions, stopping when we find a page that is not 5214343d008SDavid Howells * immediately lockable, is not dirty or is missing, or we reach the 5224343d008SDavid Howells * end of the range. 5234343d008SDavid Howells */ 52431143d5dSDavid Howells start = primary_page->index; 5254343d008SDavid Howells priv = page_private(primary_page); 52667d78a6fSDavid Howells offset = afs_page_dirty_from(primary_page, priv); 52767d78a6fSDavid Howells to = afs_page_dirty_to(primary_page, priv); 52867d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("store"), primary_page); 5294343d008SDavid Howells 5304343d008SDavid Howells WARN_ON(offset == to); 53113524ab3SDavid Howells if (offset == to) 53267d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("WARN"), primary_page); 5334343d008SDavid Howells 5345a813276SDavid Howells if (start >= final_page || 5355a813276SDavid Howells (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))) 53631143d5dSDavid Howells goto no_more; 5374343d008SDavid Howells 53831143d5dSDavid Howells start++; 53931143d5dSDavid Howells do { 54031143d5dSDavid Howells _debug("more %lx [%lx]", start, count); 5414343d008SDavid Howells n = final_page - start + 1; 54231143d5dSDavid Howells if (n > ARRAY_SIZE(pages)) 54331143d5dSDavid Howells n = ARRAY_SIZE(pages); 5444343d008SDavid Howells n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages); 54531143d5dSDavid Howells _debug("fgpc %u", n); 54631143d5dSDavid Howells if (n == 0) 54731143d5dSDavid Howells goto no_more; 54831143d5dSDavid Howells if (pages[0]->index != start) { 5499d577b6aSDavid Howells do { 5509d577b6aSDavid Howells put_page(pages[--n]); 5519d577b6aSDavid Howells } while (n > 0); 55231143d5dSDavid Howells goto no_more; 55331143d5dSDavid Howells } 55431143d5dSDavid Howells 55531143d5dSDavid Howells for (loop = 0; loop < n; loop++) { 55631143d5dSDavid Howells page = pages[loop]; 5575a813276SDavid Howells if (to != PAGE_SIZE && 5585a813276SDavid Howells !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) 5595a813276SDavid Howells break; 5604343d008SDavid Howells if (page->index > final_page) 56131143d5dSDavid Howells break; 562529ae9aaSNick Piggin if (!trylock_page(page)) 56331143d5dSDavid Howells break; 5644343d008SDavid Howells if (!PageDirty(page) || PageWriteback(page)) { 56531143d5dSDavid Howells unlock_page(page); 56631143d5dSDavid Howells break; 56731143d5dSDavid Howells } 5684343d008SDavid Howells 5694343d008SDavid Howells priv = page_private(page); 57067d78a6fSDavid Howells f = afs_page_dirty_from(page, priv); 57167d78a6fSDavid Howells t = afs_page_dirty_to(page, priv); 5725a813276SDavid Howells if (f != 0 && 5735a813276SDavid Howells !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) { 5744343d008SDavid Howells unlock_page(page); 5754343d008SDavid Howells break; 5764343d008SDavid Howells } 5774343d008SDavid Howells to = t; 5784343d008SDavid Howells 57967d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("store+"), page); 58013524ab3SDavid Howells 58131143d5dSDavid Howells if (!clear_page_dirty_for_io(page)) 58231143d5dSDavid Howells BUG(); 58331143d5dSDavid Howells if (test_set_page_writeback(page)) 58431143d5dSDavid Howells BUG(); 58531143d5dSDavid Howells unlock_page(page); 58631143d5dSDavid Howells put_page(page); 58731143d5dSDavid Howells } 58831143d5dSDavid Howells count += loop; 58931143d5dSDavid Howells if (loop < n) { 59031143d5dSDavid Howells for (; loop < n; loop++) 59131143d5dSDavid Howells put_page(pages[loop]); 59231143d5dSDavid Howells goto no_more; 59331143d5dSDavid Howells } 59431143d5dSDavid Howells 59531143d5dSDavid Howells start += loop; 5964343d008SDavid Howells } while (start <= final_page && count < 65536); 59731143d5dSDavid Howells 59831143d5dSDavid Howells no_more: 5994343d008SDavid Howells /* We now have a contiguous set of dirty pages, each with writeback 6004343d008SDavid Howells * set; the first page is still locked at this point, but all the rest 6014343d008SDavid Howells * have been unlocked. 6024343d008SDavid Howells */ 6034343d008SDavid Howells unlock_page(primary_page); 6044343d008SDavid Howells 60531143d5dSDavid Howells first = primary_page->index; 60631143d5dSDavid Howells last = first + count - 1; 60731143d5dSDavid Howells 608793fe82eSDavid Howells end = (loff_t)last * PAGE_SIZE + to; 609793fe82eSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 610793fe82eSDavid Howells 61131143d5dSDavid Howells _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); 612793fe82eSDavid Howells if (end > i_size) 613793fe82eSDavid Howells to = i_size & ~PAGE_MASK; 61431143d5dSDavid Howells 615d383e346SDavid Howells ret = afs_store_data(mapping, first, last, offset, to, false); 61631143d5dSDavid Howells switch (ret) { 6174343d008SDavid Howells case 0: 6184343d008SDavid Howells ret = count; 6194343d008SDavid Howells break; 6204343d008SDavid Howells 6214343d008SDavid Howells default: 6224343d008SDavid Howells pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); 623df561f66SGustavo A. R. Silva fallthrough; 6244343d008SDavid Howells case -EACCES: 6254343d008SDavid Howells case -EPERM: 6264343d008SDavid Howells case -ENOKEY: 6274343d008SDavid Howells case -EKEYEXPIRED: 6284343d008SDavid Howells case -EKEYREJECTED: 6294343d008SDavid Howells case -EKEYREVOKED: 6304343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 6314343d008SDavid Howells mapping_set_error(mapping, ret); 6324343d008SDavid Howells break; 6334343d008SDavid Howells 63431143d5dSDavid Howells case -EDQUOT: 63531143d5dSDavid Howells case -ENOSPC: 6364343d008SDavid Howells afs_redirty_pages(wbc, mapping, first, last); 6374343d008SDavid Howells mapping_set_error(mapping, -ENOSPC); 63831143d5dSDavid Howells break; 6394343d008SDavid Howells 64031143d5dSDavid Howells case -EROFS: 64131143d5dSDavid Howells case -EIO: 64231143d5dSDavid Howells case -EREMOTEIO: 64331143d5dSDavid Howells case -EFBIG: 64431143d5dSDavid Howells case -ENOENT: 64531143d5dSDavid Howells case -ENOMEDIUM: 64631143d5dSDavid Howells case -ENXIO: 647f51375cdSDavid Howells trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail); 6484343d008SDavid Howells afs_kill_pages(mapping, first, last); 6494343d008SDavid Howells mapping_set_error(mapping, ret); 65031143d5dSDavid Howells break; 65131143d5dSDavid Howells } 65231143d5dSDavid Howells 65331143d5dSDavid Howells _leave(" = %d", ret); 65431143d5dSDavid Howells return ret; 65531143d5dSDavid Howells } 65631143d5dSDavid Howells 65731143d5dSDavid Howells /* 65831143d5dSDavid Howells * write a page back to the server 65931143d5dSDavid Howells * - the caller locked the page for us 66031143d5dSDavid Howells */ 66131143d5dSDavid Howells int afs_writepage(struct page *page, struct writeback_control *wbc) 66231143d5dSDavid Howells { 66331143d5dSDavid Howells int ret; 66431143d5dSDavid Howells 66531143d5dSDavid Howells _enter("{%lx},", page->index); 66631143d5dSDavid Howells 6674343d008SDavid Howells ret = afs_write_back_from_locked_page(page->mapping, wbc, page, 6684343d008SDavid Howells wbc->range_end >> PAGE_SHIFT); 66931143d5dSDavid Howells if (ret < 0) { 67031143d5dSDavid Howells _leave(" = %d", ret); 67131143d5dSDavid Howells return 0; 67231143d5dSDavid Howells } 67331143d5dSDavid Howells 67431143d5dSDavid Howells wbc->nr_to_write -= ret; 67531143d5dSDavid Howells 67631143d5dSDavid Howells _leave(" = 0"); 67731143d5dSDavid Howells return 0; 67831143d5dSDavid Howells } 67931143d5dSDavid Howells 68031143d5dSDavid Howells /* 68131143d5dSDavid Howells * write a region of pages back to the server 68231143d5dSDavid Howells */ 683c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping, 68431143d5dSDavid Howells struct writeback_control *wbc, 68531143d5dSDavid Howells pgoff_t index, pgoff_t end, pgoff_t *_next) 68631143d5dSDavid Howells { 68731143d5dSDavid Howells struct page *page; 68831143d5dSDavid Howells int ret, n; 68931143d5dSDavid Howells 69031143d5dSDavid Howells _enter(",,%lx,%lx,", index, end); 69131143d5dSDavid Howells 69231143d5dSDavid Howells do { 693aef6e415SJan Kara n = find_get_pages_range_tag(mapping, &index, end, 694aef6e415SJan Kara PAGECACHE_TAG_DIRTY, 1, &page); 69531143d5dSDavid Howells if (!n) 69631143d5dSDavid Howells break; 69731143d5dSDavid Howells 69831143d5dSDavid Howells _debug("wback %lx", page->index); 69931143d5dSDavid Howells 700b93b0163SMatthew Wilcox /* 701b93b0163SMatthew Wilcox * at this point we hold neither the i_pages lock nor the 702b93b0163SMatthew Wilcox * page lock: the page may be truncated or invalidated 703b93b0163SMatthew Wilcox * (changing page->mapping to NULL), or even swizzled 704b93b0163SMatthew Wilcox * back from swapper_space to tmpfs file mapping 70531143d5dSDavid Howells */ 7064343d008SDavid Howells ret = lock_page_killable(page); 7074343d008SDavid Howells if (ret < 0) { 7084343d008SDavid Howells put_page(page); 7094343d008SDavid Howells _leave(" = %d", ret); 7104343d008SDavid Howells return ret; 7114343d008SDavid Howells } 71231143d5dSDavid Howells 713c5051c7bSDavid Howells if (page->mapping != mapping || !PageDirty(page)) { 71431143d5dSDavid Howells unlock_page(page); 71509cbfeafSKirill A. Shutemov put_page(page); 71631143d5dSDavid Howells continue; 71731143d5dSDavid Howells } 71831143d5dSDavid Howells 719c5051c7bSDavid Howells if (PageWriteback(page)) { 720c5051c7bSDavid Howells unlock_page(page); 72131143d5dSDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) 72231143d5dSDavid Howells wait_on_page_writeback(page); 72329c8bbbdSDavid Howells put_page(page); 72431143d5dSDavid Howells continue; 72531143d5dSDavid Howells } 72631143d5dSDavid Howells 72765a15109SDavid Howells if (!clear_page_dirty_for_io(page)) 72865a15109SDavid Howells BUG(); 7294343d008SDavid Howells ret = afs_write_back_from_locked_page(mapping, wbc, page, end); 73009cbfeafSKirill A. Shutemov put_page(page); 73131143d5dSDavid Howells if (ret < 0) { 73231143d5dSDavid Howells _leave(" = %d", ret); 73331143d5dSDavid Howells return ret; 73431143d5dSDavid Howells } 73531143d5dSDavid Howells 73631143d5dSDavid Howells wbc->nr_to_write -= ret; 73731143d5dSDavid Howells 73831143d5dSDavid Howells cond_resched(); 73931143d5dSDavid Howells } while (index < end && wbc->nr_to_write > 0); 74031143d5dSDavid Howells 74131143d5dSDavid Howells *_next = index; 74231143d5dSDavid Howells _leave(" = 0 [%lx]", *_next); 74331143d5dSDavid Howells return 0; 74431143d5dSDavid Howells } 74531143d5dSDavid Howells 74631143d5dSDavid Howells /* 74731143d5dSDavid Howells * write some of the pending data back to the server 74831143d5dSDavid Howells */ 74931143d5dSDavid Howells int afs_writepages(struct address_space *mapping, 75031143d5dSDavid Howells struct writeback_control *wbc) 75131143d5dSDavid Howells { 752ec0fa0b6SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 75331143d5dSDavid Howells pgoff_t start, end, next; 75431143d5dSDavid Howells int ret; 75531143d5dSDavid Howells 75631143d5dSDavid Howells _enter(""); 75731143d5dSDavid Howells 758ec0fa0b6SDavid Howells /* We have to be careful as we can end up racing with setattr() 759ec0fa0b6SDavid Howells * truncating the pagecache since the caller doesn't take a lock here 760ec0fa0b6SDavid Howells * to prevent it. 761ec0fa0b6SDavid Howells */ 762ec0fa0b6SDavid Howells if (wbc->sync_mode == WB_SYNC_ALL) 763ec0fa0b6SDavid Howells down_read(&vnode->validate_lock); 764ec0fa0b6SDavid Howells else if (!down_read_trylock(&vnode->validate_lock)) 765ec0fa0b6SDavid Howells return 0; 766ec0fa0b6SDavid Howells 76731143d5dSDavid Howells if (wbc->range_cyclic) { 76831143d5dSDavid Howells start = mapping->writeback_index; 76931143d5dSDavid Howells end = -1; 77031143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 7711b430beeSWu Fengguang if (start > 0 && wbc->nr_to_write > 0 && ret == 0) 77231143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, start, 77331143d5dSDavid Howells &next); 77431143d5dSDavid Howells mapping->writeback_index = next; 77531143d5dSDavid Howells } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { 77609cbfeafSKirill A. Shutemov end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT); 77731143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, 0, end, &next); 77831143d5dSDavid Howells if (wbc->nr_to_write > 0) 77931143d5dSDavid Howells mapping->writeback_index = next; 78031143d5dSDavid Howells } else { 78109cbfeafSKirill A. Shutemov start = wbc->range_start >> PAGE_SHIFT; 78209cbfeafSKirill A. Shutemov end = wbc->range_end >> PAGE_SHIFT; 78331143d5dSDavid Howells ret = afs_writepages_region(mapping, wbc, start, end, &next); 78431143d5dSDavid Howells } 78531143d5dSDavid Howells 786ec0fa0b6SDavid Howells up_read(&vnode->validate_lock); 78731143d5dSDavid Howells _leave(" = %d", ret); 78831143d5dSDavid Howells return ret; 78931143d5dSDavid Howells } 79031143d5dSDavid Howells 79131143d5dSDavid Howells /* 79231143d5dSDavid Howells * write to an AFS file 79331143d5dSDavid Howells */ 79450b5551dSAl Viro ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) 79531143d5dSDavid Howells { 796496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); 79731143d5dSDavid Howells ssize_t result; 79850b5551dSAl Viro size_t count = iov_iter_count(from); 79931143d5dSDavid Howells 8003b6492dfSDavid Howells _enter("{%llx:%llu},{%zu},", 80150b5551dSAl Viro vnode->fid.vid, vnode->fid.vnode, count); 80231143d5dSDavid Howells 80331143d5dSDavid Howells if (IS_SWAPFILE(&vnode->vfs_inode)) { 80431143d5dSDavid Howells printk(KERN_INFO 80531143d5dSDavid Howells "AFS: Attempt to write to active swap file!\n"); 80631143d5dSDavid Howells return -EBUSY; 80731143d5dSDavid Howells } 80831143d5dSDavid Howells 80931143d5dSDavid Howells if (!count) 81031143d5dSDavid Howells return 0; 81131143d5dSDavid Howells 81250b5551dSAl Viro result = generic_file_write_iter(iocb, from); 81331143d5dSDavid Howells 81431143d5dSDavid Howells _leave(" = %zd", result); 81531143d5dSDavid Howells return result; 81631143d5dSDavid Howells } 81731143d5dSDavid Howells 81831143d5dSDavid Howells /* 81931143d5dSDavid Howells * flush any dirty pages for this process, and check for write errors. 82031143d5dSDavid Howells * - the return status from this call provides a reliable indication of 82131143d5dSDavid Howells * whether any write errors occurred for this process. 82231143d5dSDavid Howells */ 82302c24a82SJosef Bacik int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 82431143d5dSDavid Howells { 8253c981bfcSAl Viro struct inode *inode = file_inode(file); 8263c981bfcSAl Viro struct afs_vnode *vnode = AFS_FS_I(inode); 82731143d5dSDavid Howells 8283b6492dfSDavid Howells _enter("{%llx:%llu},{n=%pD},%d", 8293c981bfcSAl Viro vnode->fid.vid, vnode->fid.vnode, file, 83031143d5dSDavid Howells datasync); 83131143d5dSDavid Howells 8324343d008SDavid Howells return file_write_and_wait_range(file, start, end); 83331143d5dSDavid Howells } 8349b3f26c9SDavid Howells 8359b3f26c9SDavid Howells /* 8369b3f26c9SDavid Howells * notification that a previously read-only page is about to become writable 8379b3f26c9SDavid Howells * - if it returns an error, the caller will deliver a bus error signal 8389b3f26c9SDavid Howells */ 8390722f186SSouptick Joarder vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) 8409b3f26c9SDavid Howells { 8411cf7a151SDavid Howells struct file *file = vmf->vma->vm_file; 8421cf7a151SDavid Howells struct inode *inode = file_inode(file); 8431cf7a151SDavid Howells struct afs_vnode *vnode = AFS_FS_I(inode); 8441cf7a151SDavid Howells unsigned long priv; 8459b3f26c9SDavid Howells 8463b6492dfSDavid Howells _enter("{{%llx:%llu}},{%lx}", 8471cf7a151SDavid Howells vnode->fid.vid, vnode->fid.vnode, vmf->page->index); 8489b3f26c9SDavid Howells 8491cf7a151SDavid Howells sb_start_pagefault(inode->i_sb); 8501cf7a151SDavid Howells 8511cf7a151SDavid Howells /* Wait for the page to be written to the cache before we allow it to 8521cf7a151SDavid Howells * be modified. We then assume the entire page will need writing back. 8531cf7a151SDavid Howells */ 8549b3f26c9SDavid Howells 85575b69799SMatthew Wilcox (Oracle) if (wait_on_page_writeback_killable(vmf->page)) 8561cf7a151SDavid Howells return VM_FAULT_RETRY; 8571cf7a151SDavid Howells 8581cf7a151SDavid Howells if (lock_page_killable(vmf->page) < 0) 8591cf7a151SDavid Howells return VM_FAULT_RETRY; 8601cf7a151SDavid Howells 8611cf7a151SDavid Howells /* We mustn't change page->private until writeback is complete as that 8621cf7a151SDavid Howells * details the portion of the page we need to write back and we might 8631cf7a151SDavid Howells * need to redirty the page if there's a problem. 8641cf7a151SDavid Howells */ 8651cf7a151SDavid Howells wait_on_page_writeback(vmf->page); 8661cf7a151SDavid Howells 86767d78a6fSDavid Howells priv = afs_page_dirty(vmf->page, 0, PAGE_SIZE); 868f86726a6SDavid Howells priv = afs_page_dirty_mmapped(priv); 869fa04a40bSDavid Howells if (PagePrivate(vmf->page)) 8701cf7a151SDavid Howells set_page_private(vmf->page, priv); 871fa04a40bSDavid Howells else 872fa04a40bSDavid Howells attach_page_private(vmf->page, (void *)priv); 87367d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"), vmf->page); 874bb413489SDavid Howells file_update_time(file); 8751cf7a151SDavid Howells 8761cf7a151SDavid Howells sb_end_pagefault(inode->i_sb); 8771cf7a151SDavid Howells return VM_FAULT_LOCKED; 8789b3f26c9SDavid Howells } 8794343d008SDavid Howells 8804343d008SDavid Howells /* 8814343d008SDavid Howells * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. 8824343d008SDavid Howells */ 8834343d008SDavid Howells void afs_prune_wb_keys(struct afs_vnode *vnode) 8844343d008SDavid Howells { 8854343d008SDavid Howells LIST_HEAD(graveyard); 8864343d008SDavid Howells struct afs_wb_key *wbk, *tmp; 8874343d008SDavid Howells 8884343d008SDavid Howells /* Discard unused keys */ 8894343d008SDavid Howells spin_lock(&vnode->wb_lock); 8904343d008SDavid Howells 8914343d008SDavid Howells if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && 8924343d008SDavid Howells !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { 8934343d008SDavid Howells list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { 8944343d008SDavid Howells if (refcount_read(&wbk->usage) == 1) 8954343d008SDavid Howells list_move(&wbk->vnode_link, &graveyard); 8964343d008SDavid Howells } 8974343d008SDavid Howells } 8984343d008SDavid Howells 8994343d008SDavid Howells spin_unlock(&vnode->wb_lock); 9004343d008SDavid Howells 9014343d008SDavid Howells while (!list_empty(&graveyard)) { 9024343d008SDavid Howells wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); 9034343d008SDavid Howells list_del(&wbk->vnode_link); 9044343d008SDavid Howells afs_put_wb_key(wbk); 9054343d008SDavid Howells } 9064343d008SDavid Howells } 9074343d008SDavid Howells 9084343d008SDavid Howells /* 9094343d008SDavid Howells * Clean up a page during invalidation. 9104343d008SDavid Howells */ 9114343d008SDavid Howells int afs_launder_page(struct page *page) 9124343d008SDavid Howells { 9134343d008SDavid Howells struct address_space *mapping = page->mapping; 9144343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 9154343d008SDavid Howells unsigned long priv; 9164343d008SDavid Howells unsigned int f, t; 9174343d008SDavid Howells int ret = 0; 9184343d008SDavid Howells 9194343d008SDavid Howells _enter("{%lx}", page->index); 9204343d008SDavid Howells 9214343d008SDavid Howells priv = page_private(page); 9224343d008SDavid Howells if (clear_page_dirty_for_io(page)) { 9234343d008SDavid Howells f = 0; 9244343d008SDavid Howells t = PAGE_SIZE; 9254343d008SDavid Howells if (PagePrivate(page)) { 92667d78a6fSDavid Howells f = afs_page_dirty_from(page, priv); 92767d78a6fSDavid Howells t = afs_page_dirty_to(page, priv); 9284343d008SDavid Howells } 9294343d008SDavid Howells 93067d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("launder"), page); 931d383e346SDavid Howells ret = afs_store_data(mapping, page->index, page->index, t, f, true); 9324343d008SDavid Howells } 9334343d008SDavid Howells 93467d78a6fSDavid Howells detach_page_private(page); 93567d78a6fSDavid Howells trace_afs_page_dirty(vnode, tracepoint_string("laundered"), page); 9364343d008SDavid Howells return ret; 93731143d5dSDavid Howells } 938