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> 143003bbd0SDavid Howells #include <linux/netfs.h> 153003bbd0SDavid Howells #include <linux/fscache.h> 1631143d5dSDavid Howells #include "internal.h" 1731143d5dSDavid Howells 1831143d5dSDavid Howells /* 1931143d5dSDavid Howells * mark a page as having been made dirty and thus needing writeback 2031143d5dSDavid Howells */ 2131143d5dSDavid Howells int afs_set_page_dirty(struct page *page) 2231143d5dSDavid Howells { 2331143d5dSDavid Howells _enter(""); 2431143d5dSDavid Howells return __set_page_dirty_nobuffers(page); 2531143d5dSDavid Howells } 2631143d5dSDavid Howells 2731143d5dSDavid Howells /* 2831143d5dSDavid Howells * prepare to perform part of a write to a page 2931143d5dSDavid Howells */ 3015b4650eSNick Piggin int afs_write_begin(struct file *file, struct address_space *mapping, 3115b4650eSNick Piggin loff_t pos, unsigned len, unsigned flags, 3221db2cdcSDavid Howells struct page **_page, void **fsdata) 3331143d5dSDavid Howells { 34496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 35*78525c74SDavid Howells struct folio *folio; 364343d008SDavid Howells unsigned long priv; 37e87b03f5SDavid Howells unsigned f, from; 38e87b03f5SDavid Howells unsigned t, to; 39e87b03f5SDavid Howells pgoff_t index; 4031143d5dSDavid Howells int ret; 4131143d5dSDavid Howells 42e87b03f5SDavid Howells _enter("{%llx:%llu},%llx,%x", 43e87b03f5SDavid Howells vnode->fid.vid, vnode->fid.vnode, pos, len); 4431143d5dSDavid Howells 453003bbd0SDavid Howells /* Prefetch area to be written into the cache if we're caching this 463003bbd0SDavid Howells * file. We need to do this before we get a lock on the page in case 473003bbd0SDavid Howells * there's more than one writer competing for the same cache block. 483003bbd0SDavid Howells */ 49*78525c74SDavid Howells ret = netfs_write_begin(file, mapping, pos, len, flags, &folio, fsdata, 503003bbd0SDavid Howells &afs_req_ops, NULL); 513003bbd0SDavid Howells if (ret < 0) 5231143d5dSDavid Howells return ret; 53630f5ddaSDavid Howells 54*78525c74SDavid Howells index = folio_index(folio); 55e87b03f5SDavid Howells from = pos - index * PAGE_SIZE; 56e87b03f5SDavid Howells to = from + len; 57e87b03f5SDavid Howells 5831143d5dSDavid Howells try_again: 594343d008SDavid Howells /* See if this page is already partially written in a way that we can 604343d008SDavid Howells * merge the new write with. 614343d008SDavid Howells */ 62*78525c74SDavid Howells if (folio_test_private(folio)) { 63*78525c74SDavid Howells priv = (unsigned long)folio_get_private(folio); 64*78525c74SDavid Howells f = afs_folio_dirty_from(folio, priv); 65*78525c74SDavid Howells t = afs_folio_dirty_to(folio, priv); 664343d008SDavid Howells ASSERTCMP(f, <=, t); 6731143d5dSDavid Howells 68*78525c74SDavid Howells if (folio_test_writeback(folio)) { 69*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("alrdy"), folio); 705a039c32SDavid Howells goto flush_conflicting_write; 715a039c32SDavid Howells } 725a813276SDavid Howells /* If the file is being filled locally, allow inter-write 735a813276SDavid Howells * spaces to be merged into writes. If it's not, only write 745a813276SDavid Howells * back what the user gives us. 755a813276SDavid Howells */ 765a813276SDavid Howells if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) && 775a813276SDavid Howells (to < f || from > t)) 784343d008SDavid Howells goto flush_conflicting_write; 7931143d5dSDavid Howells } 8031143d5dSDavid Howells 81*78525c74SDavid Howells *_page = &folio->page; 824343d008SDavid Howells _leave(" = 0"); 8331143d5dSDavid Howells return 0; 8431143d5dSDavid Howells 854343d008SDavid Howells /* The previous write and this write aren't adjacent or overlapping, so 864343d008SDavid Howells * flush the page out. 874343d008SDavid Howells */ 884343d008SDavid Howells flush_conflicting_write: 8931143d5dSDavid Howells _debug("flush conflict"); 90*78525c74SDavid Howells ret = folio_write_one(folio); 9121db2cdcSDavid Howells if (ret < 0) 9221db2cdcSDavid Howells goto error; 9331143d5dSDavid Howells 94*78525c74SDavid Howells ret = folio_lock_killable(folio); 9521db2cdcSDavid Howells if (ret < 0) 9621db2cdcSDavid Howells goto error; 9721db2cdcSDavid Howells goto try_again; 9821db2cdcSDavid Howells 9921db2cdcSDavid Howells error: 100*78525c74SDavid Howells folio_put(folio); 1014343d008SDavid Howells _leave(" = %d", ret); 1024343d008SDavid Howells return ret; 1034343d008SDavid Howells } 10431143d5dSDavid Howells 10531143d5dSDavid Howells /* 10631143d5dSDavid Howells * finalise part of a write to a page 10731143d5dSDavid Howells */ 10815b4650eSNick Piggin int afs_write_end(struct file *file, struct address_space *mapping, 10915b4650eSNick Piggin loff_t pos, unsigned len, unsigned copied, 110*78525c74SDavid Howells struct page *subpage, void *fsdata) 11131143d5dSDavid Howells { 112*78525c74SDavid Howells struct folio *folio = page_folio(subpage); 113496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 114f792e3acSDavid Howells unsigned long priv; 115*78525c74SDavid Howells unsigned int f, from = offset_in_folio(folio, pos); 116f792e3acSDavid Howells unsigned int t, to = from + copied; 11731143d5dSDavid Howells loff_t i_size, maybe_i_size; 11831143d5dSDavid Howells 1193b6492dfSDavid Howells _enter("{%llx:%llu},{%lx}", 120*78525c74SDavid Howells vnode->fid.vid, vnode->fid.vnode, folio_index(folio)); 12131143d5dSDavid Howells 122*78525c74SDavid Howells if (!folio_test_uptodate(folio)) { 12366e9c6a8SDavid Howells if (copied < len) { 12466e9c6a8SDavid Howells copied = 0; 12566e9c6a8SDavid Howells goto out; 12666e9c6a8SDavid Howells } 12766e9c6a8SDavid Howells 128*78525c74SDavid Howells folio_mark_uptodate(folio); 12966e9c6a8SDavid Howells } 13066e9c6a8SDavid Howells 1313ad216eeSDavid Howells if (copied == 0) 1323ad216eeSDavid Howells goto out; 1333ad216eeSDavid Howells 13415b4650eSNick Piggin maybe_i_size = pos + copied; 13531143d5dSDavid Howells 13631143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 13731143d5dSDavid Howells if (maybe_i_size > i_size) { 1381f32ef79SDavid Howells write_seqlock(&vnode->cb_lock); 13931143d5dSDavid Howells i_size = i_size_read(&vnode->vfs_inode); 14031143d5dSDavid Howells if (maybe_i_size > i_size) 1419d37e1caSDavid Howells afs_set_i_size(vnode, maybe_i_size); 1421f32ef79SDavid Howells write_sequnlock(&vnode->cb_lock); 14331143d5dSDavid Howells } 14431143d5dSDavid Howells 145*78525c74SDavid Howells if (folio_test_private(folio)) { 146*78525c74SDavid Howells priv = (unsigned long)folio_get_private(folio); 147*78525c74SDavid Howells f = afs_folio_dirty_from(folio, priv); 148*78525c74SDavid Howells t = afs_folio_dirty_to(folio, priv); 149f792e3acSDavid Howells if (from < f) 150f792e3acSDavid Howells f = from; 151f792e3acSDavid Howells if (to > t) 152f792e3acSDavid Howells t = to; 153*78525c74SDavid Howells priv = afs_folio_dirty(folio, f, t); 154*78525c74SDavid Howells folio_change_private(folio, (void *)priv); 155*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("dirty+"), folio); 156f792e3acSDavid Howells } else { 157*78525c74SDavid Howells priv = afs_folio_dirty(folio, from, to); 158*78525c74SDavid Howells folio_attach_private(folio, (void *)priv); 159*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("dirty"), folio); 160f792e3acSDavid Howells } 161f792e3acSDavid Howells 162*78525c74SDavid Howells if (folio_mark_dirty(folio)) 163*78525c74SDavid Howells _debug("dirtied %lx", folio_index(folio)); 164afae457dSDavid Howells 165afae457dSDavid Howells out: 166*78525c74SDavid Howells folio_unlock(folio); 167*78525c74SDavid Howells folio_put(folio); 1683003bbd0SDavid Howells return copied; 16931143d5dSDavid Howells } 17031143d5dSDavid Howells 17131143d5dSDavid Howells /* 17231143d5dSDavid Howells * kill all the pages in the given range 17331143d5dSDavid Howells */ 1744343d008SDavid Howells static void afs_kill_pages(struct address_space *mapping, 175e87b03f5SDavid Howells loff_t start, loff_t len) 17631143d5dSDavid Howells { 1774343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 178*78525c74SDavid Howells struct folio *folio; 179*78525c74SDavid Howells pgoff_t index = start / PAGE_SIZE; 180*78525c74SDavid Howells pgoff_t last = (start + len - 1) / PAGE_SIZE, next; 18131143d5dSDavid Howells 182e87b03f5SDavid Howells _enter("{%llx:%llu},%llx @%llx", 183e87b03f5SDavid Howells vnode->fid.vid, vnode->fid.vnode, len, start); 18431143d5dSDavid Howells 18531143d5dSDavid Howells do { 186*78525c74SDavid Howells _debug("kill %lx (to %lx)", index, last); 18731143d5dSDavid Howells 188*78525c74SDavid Howells folio = filemap_get_folio(mapping, index); 189*78525c74SDavid Howells if (!folio) { 190*78525c74SDavid Howells next = index + 1; 191*78525c74SDavid Howells continue; 1924343d008SDavid Howells } 1934343d008SDavid Howells 194*78525c74SDavid Howells next = folio_next_index(folio); 195*78525c74SDavid Howells 196*78525c74SDavid Howells folio_clear_uptodate(folio); 197*78525c74SDavid Howells folio_end_writeback(folio); 198*78525c74SDavid Howells folio_lock(folio); 199*78525c74SDavid Howells generic_error_remove_page(mapping, &folio->page); 200*78525c74SDavid Howells folio_unlock(folio); 201*78525c74SDavid Howells folio_put(folio); 202*78525c74SDavid Howells 203*78525c74SDavid Howells } while (index = next, index <= last); 2044343d008SDavid Howells 2054343d008SDavid Howells _leave(""); 2064343d008SDavid Howells } 2074343d008SDavid Howells 2084343d008SDavid Howells /* 2094343d008SDavid Howells * Redirty all the pages in a given range. 2104343d008SDavid Howells */ 2114343d008SDavid Howells static void afs_redirty_pages(struct writeback_control *wbc, 2124343d008SDavid Howells struct address_space *mapping, 213e87b03f5SDavid Howells loff_t start, loff_t len) 2144343d008SDavid Howells { 2154343d008SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 216*78525c74SDavid Howells struct folio *folio; 217*78525c74SDavid Howells pgoff_t index = start / PAGE_SIZE; 218*78525c74SDavid Howells pgoff_t last = (start + len - 1) / PAGE_SIZE, next; 2194343d008SDavid Howells 220e87b03f5SDavid Howells _enter("{%llx:%llu},%llx @%llx", 221e87b03f5SDavid Howells vnode->fid.vid, vnode->fid.vnode, len, start); 2224343d008SDavid Howells 2234343d008SDavid Howells do { 224e87b03f5SDavid Howells _debug("redirty %llx @%llx", len, start); 2254343d008SDavid Howells 226*78525c74SDavid Howells folio = filemap_get_folio(mapping, index); 227*78525c74SDavid Howells if (!folio) { 228*78525c74SDavid Howells next = index + 1; 229*78525c74SDavid Howells continue; 23031143d5dSDavid Howells } 23131143d5dSDavid Howells 232*78525c74SDavid Howells next = index + folio_nr_pages(folio); 233*78525c74SDavid Howells folio_redirty_for_writepage(wbc, folio); 234*78525c74SDavid Howells folio_end_writeback(folio); 235*78525c74SDavid Howells folio_put(folio); 236*78525c74SDavid Howells } while (index = next, index <= last); 23731143d5dSDavid Howells 23831143d5dSDavid Howells _leave(""); 23931143d5dSDavid Howells } 24031143d5dSDavid Howells 24131143d5dSDavid Howells /* 242a58823acSDavid Howells * completion of write to server 243a58823acSDavid Howells */ 244e87b03f5SDavid Howells static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsigned int len) 245a58823acSDavid Howells { 246bd80d8a8SDavid Howells struct address_space *mapping = vnode->vfs_inode.i_mapping; 247*78525c74SDavid Howells struct folio *folio; 248e87b03f5SDavid Howells pgoff_t end; 249bd80d8a8SDavid Howells 250e87b03f5SDavid Howells XA_STATE(xas, &mapping->i_pages, start / PAGE_SIZE); 251a58823acSDavid Howells 252e87b03f5SDavid Howells _enter("{%llx:%llu},{%x @%llx}", 253e87b03f5SDavid Howells vnode->fid.vid, vnode->fid.vnode, len, start); 254a58823acSDavid Howells 255bd80d8a8SDavid Howells rcu_read_lock(); 256a58823acSDavid Howells 257e87b03f5SDavid Howells end = (start + len - 1) / PAGE_SIZE; 258*78525c74SDavid Howells xas_for_each(&xas, folio, end) { 259*78525c74SDavid Howells if (!folio_test_writeback(folio)) { 260*78525c74SDavid Howells kdebug("bad %x @%llx page %lx %lx", 261*78525c74SDavid Howells len, start, folio_index(folio), end); 262*78525c74SDavid Howells ASSERT(folio_test_writeback(folio)); 263e87b03f5SDavid Howells } 264a58823acSDavid Howells 265*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("clear"), folio); 266*78525c74SDavid Howells folio_detach_private(folio); 267*78525c74SDavid Howells folio_end_writeback(folio); 268a58823acSDavid Howells } 269bd80d8a8SDavid Howells 270bd80d8a8SDavid Howells rcu_read_unlock(); 271a58823acSDavid Howells 272a58823acSDavid Howells afs_prune_wb_keys(vnode); 273a58823acSDavid Howells _leave(""); 274a58823acSDavid Howells } 275a58823acSDavid Howells 276a58823acSDavid Howells /* 277e49c7b2fSDavid Howells * Find a key to use for the writeback. We cached the keys used to author the 278e49c7b2fSDavid Howells * writes on the vnode. *_wbk will contain the last writeback key used or NULL 279e49c7b2fSDavid Howells * and we need to start from there if it's set. 280e49c7b2fSDavid Howells */ 281e49c7b2fSDavid Howells static int afs_get_writeback_key(struct afs_vnode *vnode, 282e49c7b2fSDavid Howells struct afs_wb_key **_wbk) 283e49c7b2fSDavid Howells { 284e49c7b2fSDavid Howells struct afs_wb_key *wbk = NULL; 285e49c7b2fSDavid Howells struct list_head *p; 286e49c7b2fSDavid Howells int ret = -ENOKEY, ret2; 287e49c7b2fSDavid Howells 288e49c7b2fSDavid Howells spin_lock(&vnode->wb_lock); 289e49c7b2fSDavid Howells if (*_wbk) 290e49c7b2fSDavid Howells p = (*_wbk)->vnode_link.next; 291e49c7b2fSDavid Howells else 292e49c7b2fSDavid Howells p = vnode->wb_keys.next; 293e49c7b2fSDavid Howells 294e49c7b2fSDavid Howells while (p != &vnode->wb_keys) { 295e49c7b2fSDavid Howells wbk = list_entry(p, struct afs_wb_key, vnode_link); 296e49c7b2fSDavid Howells _debug("wbk %u", key_serial(wbk->key)); 297e49c7b2fSDavid Howells ret2 = key_validate(wbk->key); 298e49c7b2fSDavid Howells if (ret2 == 0) { 299e49c7b2fSDavid Howells refcount_inc(&wbk->usage); 300e49c7b2fSDavid Howells _debug("USE WB KEY %u", key_serial(wbk->key)); 301e49c7b2fSDavid Howells break; 302e49c7b2fSDavid Howells } 303e49c7b2fSDavid Howells 304e49c7b2fSDavid Howells wbk = NULL; 305e49c7b2fSDavid Howells if (ret == -ENOKEY) 306e49c7b2fSDavid Howells ret = ret2; 307e49c7b2fSDavid Howells p = p->next; 308e49c7b2fSDavid Howells } 309e49c7b2fSDavid Howells 310e49c7b2fSDavid Howells spin_unlock(&vnode->wb_lock); 311e49c7b2fSDavid Howells if (*_wbk) 312e49c7b2fSDavid Howells afs_put_wb_key(*_wbk); 313e49c7b2fSDavid Howells *_wbk = wbk; 314e49c7b2fSDavid Howells return 0; 315e49c7b2fSDavid Howells } 316e49c7b2fSDavid Howells 317e49c7b2fSDavid Howells static void afs_store_data_success(struct afs_operation *op) 318e49c7b2fSDavid Howells { 319e49c7b2fSDavid Howells struct afs_vnode *vnode = op->file[0].vnode; 320e49c7b2fSDavid Howells 321da8d0755SDavid Howells op->ctime = op->file[0].scb.status.mtime_client; 322e49c7b2fSDavid Howells afs_vnode_commit_status(op, &op->file[0]); 323e49c7b2fSDavid Howells if (op->error == 0) { 324d383e346SDavid Howells if (!op->store.laundering) 325e87b03f5SDavid Howells afs_pages_written_back(vnode, op->store.pos, op->store.size); 326e49c7b2fSDavid Howells afs_stat_v(vnode, n_stores); 327bd80d8a8SDavid Howells atomic_long_add(op->store.size, &afs_v2net(vnode)->n_store_bytes); 328e49c7b2fSDavid Howells } 329e49c7b2fSDavid Howells } 330e49c7b2fSDavid Howells 331e49c7b2fSDavid Howells static const struct afs_operation_ops afs_store_data_operation = { 332e49c7b2fSDavid Howells .issue_afs_rpc = afs_fs_store_data, 333e49c7b2fSDavid Howells .issue_yfs_rpc = yfs_fs_store_data, 334e49c7b2fSDavid Howells .success = afs_store_data_success, 335e49c7b2fSDavid Howells }; 336e49c7b2fSDavid Howells 337e49c7b2fSDavid Howells /* 338d2ddc776SDavid Howells * write to a file 33931143d5dSDavid Howells */ 340e87b03f5SDavid Howells static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t pos, 341bd80d8a8SDavid Howells bool laundering) 34231143d5dSDavid Howells { 343e49c7b2fSDavid Howells struct afs_operation *op; 3444343d008SDavid Howells struct afs_wb_key *wbk = NULL; 345bd80d8a8SDavid Howells loff_t size = iov_iter_count(iter), i_size; 346bd80d8a8SDavid Howells int ret = -ENOKEY; 347d2ddc776SDavid Howells 348bd80d8a8SDavid Howells _enter("%s{%llx:%llu.%u},%llx,%llx", 349d2ddc776SDavid Howells vnode->volume->name, 350d2ddc776SDavid Howells vnode->fid.vid, 351d2ddc776SDavid Howells vnode->fid.vnode, 352d2ddc776SDavid Howells vnode->fid.unique, 353bd80d8a8SDavid Howells size, pos); 354d2ddc776SDavid Howells 355e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 356e49c7b2fSDavid Howells if (ret) { 3574343d008SDavid Howells _leave(" = %d [no keys]", ret); 3584343d008SDavid Howells return ret; 359d2ddc776SDavid Howells } 360d2ddc776SDavid Howells 361e49c7b2fSDavid Howells op = afs_alloc_operation(wbk->key, vnode->volume); 362e49c7b2fSDavid Howells if (IS_ERR(op)) { 363e49c7b2fSDavid Howells afs_put_wb_key(wbk); 364e49c7b2fSDavid Howells return -ENOMEM; 365d2ddc776SDavid Howells } 366d2ddc776SDavid Howells 367bd80d8a8SDavid Howells i_size = i_size_read(&vnode->vfs_inode); 368bd80d8a8SDavid Howells 369e49c7b2fSDavid Howells afs_op_set_vnode(op, 0, vnode); 370e49c7b2fSDavid Howells op->file[0].dv_delta = 1; 37122650f14SDavid Howells op->file[0].modification = true; 372bd80d8a8SDavid Howells op->store.write_iter = iter; 373bd80d8a8SDavid Howells op->store.pos = pos; 374bd80d8a8SDavid Howells op->store.size = size; 375bd80d8a8SDavid Howells op->store.i_size = max(pos + size, i_size); 376d383e346SDavid Howells op->store.laundering = laundering; 377b3597945SDavid Howells op->mtime = vnode->vfs_inode.i_mtime; 378811f04baSDavid Howells op->flags |= AFS_OPERATION_UNINTR; 379e49c7b2fSDavid Howells op->ops = &afs_store_data_operation; 380e49c7b2fSDavid Howells 381e49c7b2fSDavid Howells try_next_key: 382e49c7b2fSDavid Howells afs_begin_vnode_operation(op); 383e49c7b2fSDavid Howells afs_wait_for_operation(op); 384e49c7b2fSDavid Howells 385e49c7b2fSDavid Howells switch (op->error) { 3864343d008SDavid Howells case -EACCES: 3874343d008SDavid Howells case -EPERM: 3884343d008SDavid Howells case -ENOKEY: 3894343d008SDavid Howells case -EKEYEXPIRED: 3904343d008SDavid Howells case -EKEYREJECTED: 3914343d008SDavid Howells case -EKEYREVOKED: 3924343d008SDavid Howells _debug("next"); 393e49c7b2fSDavid Howells 394e49c7b2fSDavid Howells ret = afs_get_writeback_key(vnode, &wbk); 395e49c7b2fSDavid Howells if (ret == 0) { 396e49c7b2fSDavid Howells key_put(op->key); 397e49c7b2fSDavid Howells op->key = key_get(wbk->key); 3984343d008SDavid Howells goto try_next_key; 3994343d008SDavid Howells } 400e49c7b2fSDavid Howells break; 401e49c7b2fSDavid Howells } 4024343d008SDavid Howells 4034343d008SDavid Howells afs_put_wb_key(wbk); 404e49c7b2fSDavid Howells _leave(" = %d", op->error); 405e49c7b2fSDavid Howells return afs_put_operation(op); 406d2ddc776SDavid Howells } 407d2ddc776SDavid Howells 408d2ddc776SDavid Howells /* 409810caa3eSDavid Howells * Extend the region to be written back to include subsequent contiguously 410810caa3eSDavid Howells * dirty pages if possible, but don't sleep while doing so. 411810caa3eSDavid Howells * 412810caa3eSDavid Howells * If this page holds new content, then we can include filler zeros in the 413810caa3eSDavid Howells * writeback. 41431143d5dSDavid Howells */ 415810caa3eSDavid Howells static void afs_extend_writeback(struct address_space *mapping, 416810caa3eSDavid Howells struct afs_vnode *vnode, 417810caa3eSDavid Howells long *_count, 418e87b03f5SDavid Howells loff_t start, 419e87b03f5SDavid Howells loff_t max_len, 420e87b03f5SDavid Howells bool new_content, 421e87b03f5SDavid Howells unsigned int *_len) 42231143d5dSDavid Howells { 423e87b03f5SDavid Howells struct pagevec pvec; 424*78525c74SDavid Howells struct folio *folio; 425e87b03f5SDavid Howells unsigned long priv; 426e87b03f5SDavid Howells unsigned int psize, filler = 0; 427e87b03f5SDavid Howells unsigned int f, t; 428e87b03f5SDavid Howells loff_t len = *_len; 429e87b03f5SDavid Howells pgoff_t index = (start + len) / PAGE_SIZE; 430e87b03f5SDavid Howells bool stop = true; 431e87b03f5SDavid Howells unsigned int i; 4324343d008SDavid Howells 433e87b03f5SDavid Howells XA_STATE(xas, &mapping->i_pages, index); 434e87b03f5SDavid Howells pagevec_init(&pvec); 435e87b03f5SDavid Howells 43631143d5dSDavid Howells do { 437e87b03f5SDavid Howells /* Firstly, we gather up a batch of contiguous dirty pages 438e87b03f5SDavid Howells * under the RCU read lock - but we can't clear the dirty flags 439e87b03f5SDavid Howells * there if any of those pages are mapped. 440e87b03f5SDavid Howells */ 441e87b03f5SDavid Howells rcu_read_lock(); 442e87b03f5SDavid Howells 443*78525c74SDavid Howells xas_for_each(&xas, folio, ULONG_MAX) { 444e87b03f5SDavid Howells stop = true; 445*78525c74SDavid Howells if (xas_retry(&xas, folio)) 446e87b03f5SDavid Howells continue; 447*78525c74SDavid Howells if (xa_is_value(folio)) 448e87b03f5SDavid Howells break; 449*78525c74SDavid Howells if (folio_index(folio) != index) 450e87b03f5SDavid Howells break; 451e87b03f5SDavid Howells 452*78525c74SDavid Howells if (!folio_try_get_rcu(folio)) { 453e87b03f5SDavid Howells xas_reset(&xas); 454e87b03f5SDavid Howells continue; 45531143d5dSDavid Howells } 45631143d5dSDavid Howells 457e87b03f5SDavid Howells /* Has the page moved or been split? */ 458*78525c74SDavid Howells if (unlikely(folio != xas_reload(&xas))) { 459*78525c74SDavid Howells folio_put(folio); 4605a813276SDavid Howells break; 461581b2027SDavid Howells } 462e87b03f5SDavid Howells 463*78525c74SDavid Howells if (!folio_trylock(folio)) { 464*78525c74SDavid Howells folio_put(folio); 46531143d5dSDavid Howells break; 466581b2027SDavid Howells } 467*78525c74SDavid Howells if (!folio_test_dirty(folio) || folio_test_writeback(folio)) { 468*78525c74SDavid Howells folio_unlock(folio); 469*78525c74SDavid Howells folio_put(folio); 47031143d5dSDavid Howells break; 47131143d5dSDavid Howells } 4724343d008SDavid Howells 473*78525c74SDavid Howells psize = folio_size(folio); 474*78525c74SDavid Howells priv = (unsigned long)folio_get_private(folio); 475*78525c74SDavid Howells f = afs_folio_dirty_from(folio, priv); 476*78525c74SDavid Howells t = afs_folio_dirty_to(folio, priv); 477810caa3eSDavid Howells if (f != 0 && !new_content) { 478*78525c74SDavid Howells folio_unlock(folio); 479*78525c74SDavid Howells folio_put(folio); 4804343d008SDavid Howells break; 4814343d008SDavid Howells } 4824343d008SDavid Howells 483e87b03f5SDavid Howells len += filler + t; 484e87b03f5SDavid Howells filler = psize - t; 485e87b03f5SDavid Howells if (len >= max_len || *_count <= 0) 486e87b03f5SDavid Howells stop = true; 487e87b03f5SDavid Howells else if (t == psize || new_content) 488e87b03f5SDavid Howells stop = false; 489e87b03f5SDavid Howells 490*78525c74SDavid Howells index += folio_nr_pages(folio); 491*78525c74SDavid Howells if (!pagevec_add(&pvec, &folio->page)) 492e87b03f5SDavid Howells break; 493e87b03f5SDavid Howells if (stop) 494e87b03f5SDavid Howells break; 495e87b03f5SDavid Howells } 496e87b03f5SDavid Howells 497e87b03f5SDavid Howells if (!stop) 498e87b03f5SDavid Howells xas_pause(&xas); 499e87b03f5SDavid Howells rcu_read_unlock(); 500e87b03f5SDavid Howells 501e87b03f5SDavid Howells /* Now, if we obtained any pages, we can shift them to being 502e87b03f5SDavid Howells * writable and mark them for caching. 503e87b03f5SDavid Howells */ 504e87b03f5SDavid Howells if (!pagevec_count(&pvec)) 505e87b03f5SDavid Howells break; 506e87b03f5SDavid Howells 507e87b03f5SDavid Howells for (i = 0; i < pagevec_count(&pvec); i++) { 508*78525c74SDavid Howells folio = page_folio(pvec.pages[i]); 509*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("store+"), folio); 51013524ab3SDavid Howells 511*78525c74SDavid Howells if (!folio_clear_dirty_for_io(folio)) 51231143d5dSDavid Howells BUG(); 513*78525c74SDavid Howells if (folio_start_writeback(folio)) 51431143d5dSDavid Howells BUG(); 515e87b03f5SDavid Howells 516*78525c74SDavid Howells *_count -= folio_nr_pages(folio); 517*78525c74SDavid Howells folio_unlock(folio); 51831143d5dSDavid Howells } 51931143d5dSDavid Howells 520e87b03f5SDavid Howells pagevec_release(&pvec); 521e87b03f5SDavid Howells cond_resched(); 522e87b03f5SDavid Howells } while (!stop); 52331143d5dSDavid Howells 524e87b03f5SDavid Howells *_len = len; 525810caa3eSDavid Howells } 526810caa3eSDavid Howells 527810caa3eSDavid Howells /* 528810caa3eSDavid Howells * Synchronously write back the locked page and any subsequent non-locked dirty 529810caa3eSDavid Howells * pages. 530810caa3eSDavid Howells */ 531*78525c74SDavid Howells static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping, 532810caa3eSDavid Howells struct writeback_control *wbc, 533*78525c74SDavid Howells struct folio *folio, 534e87b03f5SDavid Howells loff_t start, loff_t end) 535810caa3eSDavid Howells { 536810caa3eSDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 537810caa3eSDavid Howells struct iov_iter iter; 538e87b03f5SDavid Howells unsigned long priv; 539e87b03f5SDavid Howells unsigned int offset, to, len, max_len; 540e87b03f5SDavid Howells loff_t i_size = i_size_read(&vnode->vfs_inode); 541810caa3eSDavid Howells bool new_content = test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); 542e87b03f5SDavid Howells long count = wbc->nr_to_write; 543810caa3eSDavid Howells int ret; 544810caa3eSDavid Howells 545*78525c74SDavid Howells _enter(",%lx,%llx-%llx", folio_index(folio), start, end); 546810caa3eSDavid Howells 547*78525c74SDavid Howells if (folio_start_writeback(folio)) 548810caa3eSDavid Howells BUG(); 549810caa3eSDavid Howells 550*78525c74SDavid Howells count -= folio_nr_pages(folio); 551e87b03f5SDavid Howells 552810caa3eSDavid Howells /* Find all consecutive lockable dirty pages that have contiguous 553810caa3eSDavid Howells * written regions, stopping when we find a page that is not 554810caa3eSDavid Howells * immediately lockable, is not dirty or is missing, or we reach the 555810caa3eSDavid Howells * end of the range. 556810caa3eSDavid Howells */ 557*78525c74SDavid Howells priv = (unsigned long)folio_get_private(folio); 558*78525c74SDavid Howells offset = afs_folio_dirty_from(folio, priv); 559*78525c74SDavid Howells to = afs_folio_dirty_to(folio, priv); 560*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("store"), folio); 561810caa3eSDavid Howells 562e87b03f5SDavid Howells len = to - offset; 563e87b03f5SDavid Howells start += offset; 564e87b03f5SDavid Howells if (start < i_size) { 565e87b03f5SDavid Howells /* Trim the write to the EOF; the extra data is ignored. Also 566e87b03f5SDavid Howells * put an upper limit on the size of a single storedata op. 567e87b03f5SDavid Howells */ 568e87b03f5SDavid Howells max_len = 65536 * 4096; 569e87b03f5SDavid Howells max_len = min_t(unsigned long long, max_len, end - start + 1); 570e87b03f5SDavid Howells max_len = min_t(unsigned long long, max_len, i_size - start); 571810caa3eSDavid Howells 572e87b03f5SDavid Howells if (len < max_len && 573*78525c74SDavid Howells (to == folio_size(folio) || new_content)) 574e87b03f5SDavid Howells afs_extend_writeback(mapping, vnode, &count, 575e87b03f5SDavid Howells start, max_len, new_content, &len); 576e87b03f5SDavid Howells len = min_t(loff_t, len, max_len); 577e87b03f5SDavid Howells } 578810caa3eSDavid Howells 5794343d008SDavid Howells /* We now have a contiguous set of dirty pages, each with writeback 5804343d008SDavid Howells * set; the first page is still locked at this point, but all the rest 5814343d008SDavid Howells * have been unlocked. 5824343d008SDavid Howells */ 583*78525c74SDavid Howells folio_unlock(folio); 5844343d008SDavid Howells 585e87b03f5SDavid Howells if (start < i_size) { 586e87b03f5SDavid Howells _debug("write back %x @%llx [%llx]", len, start, i_size); 58731143d5dSDavid Howells 588e87b03f5SDavid Howells iov_iter_xarray(&iter, WRITE, &mapping->i_pages, start, len); 589e87b03f5SDavid Howells ret = afs_store_data(vnode, &iter, start, false); 590bd80d8a8SDavid Howells } else { 591e87b03f5SDavid Howells _debug("write discard %x @%llx [%llx]", len, start, i_size); 592e87b03f5SDavid Howells 593bd80d8a8SDavid Howells /* The dirty region was entirely beyond the EOF. */ 594e87b03f5SDavid Howells afs_pages_written_back(vnode, start, len); 595bd80d8a8SDavid Howells ret = 0; 596bd80d8a8SDavid Howells } 597bd80d8a8SDavid Howells 59831143d5dSDavid Howells switch (ret) { 5994343d008SDavid Howells case 0: 600e87b03f5SDavid Howells wbc->nr_to_write = count; 601e87b03f5SDavid Howells ret = len; 6024343d008SDavid Howells break; 6034343d008SDavid Howells 6044343d008SDavid Howells default: 6054343d008SDavid Howells pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); 606df561f66SGustavo A. R. Silva fallthrough; 6074343d008SDavid Howells case -EACCES: 6084343d008SDavid Howells case -EPERM: 6094343d008SDavid Howells case -ENOKEY: 6104343d008SDavid Howells case -EKEYEXPIRED: 6114343d008SDavid Howells case -EKEYREJECTED: 6124343d008SDavid Howells case -EKEYREVOKED: 613e87b03f5SDavid Howells afs_redirty_pages(wbc, mapping, start, len); 6144343d008SDavid Howells mapping_set_error(mapping, ret); 6154343d008SDavid Howells break; 6164343d008SDavid Howells 61731143d5dSDavid Howells case -EDQUOT: 61831143d5dSDavid Howells case -ENOSPC: 619e87b03f5SDavid Howells afs_redirty_pages(wbc, mapping, start, len); 6204343d008SDavid Howells mapping_set_error(mapping, -ENOSPC); 62131143d5dSDavid Howells break; 6224343d008SDavid Howells 62331143d5dSDavid Howells case -EROFS: 62431143d5dSDavid Howells case -EIO: 62531143d5dSDavid Howells case -EREMOTEIO: 62631143d5dSDavid Howells case -EFBIG: 62731143d5dSDavid Howells case -ENOENT: 62831143d5dSDavid Howells case -ENOMEDIUM: 62931143d5dSDavid Howells case -ENXIO: 630f51375cdSDavid Howells trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail); 631e87b03f5SDavid Howells afs_kill_pages(mapping, start, len); 6324343d008SDavid Howells mapping_set_error(mapping, ret); 63331143d5dSDavid Howells break; 63431143d5dSDavid Howells } 63531143d5dSDavid Howells 63631143d5dSDavid Howells _leave(" = %d", ret); 63731143d5dSDavid Howells return ret; 63831143d5dSDavid Howells } 63931143d5dSDavid Howells 64031143d5dSDavid Howells /* 64131143d5dSDavid Howells * write a page back to the server 64231143d5dSDavid Howells * - the caller locked the page for us 64331143d5dSDavid Howells */ 644*78525c74SDavid Howells int afs_writepage(struct page *subpage, struct writeback_control *wbc) 64531143d5dSDavid Howells { 646*78525c74SDavid Howells struct folio *folio = page_folio(subpage); 647e87b03f5SDavid Howells ssize_t ret; 648e87b03f5SDavid Howells loff_t start; 64931143d5dSDavid Howells 650*78525c74SDavid Howells _enter("{%lx},", folio_index(folio)); 65131143d5dSDavid Howells 652*78525c74SDavid Howells start = folio_index(folio) * PAGE_SIZE; 653*78525c74SDavid Howells ret = afs_write_back_from_locked_folio(folio_mapping(folio), wbc, 654*78525c74SDavid Howells folio, start, LLONG_MAX - start); 65531143d5dSDavid Howells if (ret < 0) { 656e87b03f5SDavid Howells _leave(" = %zd", ret); 657e87b03f5SDavid Howells return ret; 65831143d5dSDavid Howells } 65931143d5dSDavid Howells 66031143d5dSDavid Howells _leave(" = 0"); 66131143d5dSDavid Howells return 0; 66231143d5dSDavid Howells } 66331143d5dSDavid Howells 66431143d5dSDavid Howells /* 66531143d5dSDavid Howells * write a region of pages back to the server 66631143d5dSDavid Howells */ 667c1206a2cSAdrian Bunk static int afs_writepages_region(struct address_space *mapping, 66831143d5dSDavid Howells struct writeback_control *wbc, 669e87b03f5SDavid Howells loff_t start, loff_t end, loff_t *_next) 67031143d5dSDavid Howells { 671*78525c74SDavid Howells struct folio *folio; 672*78525c74SDavid Howells struct page *head_page; 673e87b03f5SDavid Howells ssize_t ret; 674e87b03f5SDavid Howells int n; 67531143d5dSDavid Howells 676e87b03f5SDavid Howells _enter("%llx,%llx,", start, end); 67731143d5dSDavid Howells 67831143d5dSDavid Howells do { 679e87b03f5SDavid Howells pgoff_t index = start / PAGE_SIZE; 680e87b03f5SDavid Howells 681e87b03f5SDavid Howells n = find_get_pages_range_tag(mapping, &index, end / PAGE_SIZE, 682*78525c74SDavid Howells PAGECACHE_TAG_DIRTY, 1, &head_page); 68331143d5dSDavid Howells if (!n) 68431143d5dSDavid Howells break; 68531143d5dSDavid Howells 686*78525c74SDavid Howells folio = page_folio(head_page); 687*78525c74SDavid Howells start = folio_pos(folio); /* May regress with THPs */ 688e87b03f5SDavid Howells 689*78525c74SDavid Howells _debug("wback %lx", folio_index(folio)); 69031143d5dSDavid Howells 691e87b03f5SDavid Howells /* At this point we hold neither the i_pages lock nor the 692b93b0163SMatthew Wilcox * page lock: the page may be truncated or invalidated 693b93b0163SMatthew Wilcox * (changing page->mapping to NULL), or even swizzled 694b93b0163SMatthew Wilcox * back from swapper_space to tmpfs file mapping 69531143d5dSDavid Howells */ 696e87b03f5SDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) { 697*78525c74SDavid Howells ret = folio_lock_killable(folio); 6984343d008SDavid Howells if (ret < 0) { 699*78525c74SDavid Howells folio_put(folio); 7004343d008SDavid Howells return ret; 7014343d008SDavid Howells } 702e87b03f5SDavid Howells } else { 703*78525c74SDavid Howells if (!folio_trylock(folio)) { 704*78525c74SDavid Howells folio_put(folio); 705e87b03f5SDavid Howells return 0; 706e87b03f5SDavid Howells } 707e87b03f5SDavid Howells } 70831143d5dSDavid Howells 709*78525c74SDavid Howells if (folio_mapping(folio) != mapping || 710*78525c74SDavid Howells !folio_test_dirty(folio)) { 711*78525c74SDavid Howells start += folio_size(folio); 712*78525c74SDavid Howells folio_unlock(folio); 713*78525c74SDavid Howells folio_put(folio); 71431143d5dSDavid Howells continue; 71531143d5dSDavid Howells } 71631143d5dSDavid Howells 717*78525c74SDavid Howells if (folio_test_writeback(folio)) { 718*78525c74SDavid Howells folio_unlock(folio); 71931143d5dSDavid Howells if (wbc->sync_mode != WB_SYNC_NONE) 720*78525c74SDavid Howells folio_wait_writeback(folio); 721*78525c74SDavid Howells folio_put(folio); 72231143d5dSDavid Howells continue; 72331143d5dSDavid Howells } 72431143d5dSDavid Howells 725*78525c74SDavid Howells if (!folio_clear_dirty_for_io(folio)) 72665a15109SDavid Howells BUG(); 727*78525c74SDavid Howells ret = afs_write_back_from_locked_folio(mapping, wbc, folio, start, end); 728*78525c74SDavid Howells folio_put(folio); 72931143d5dSDavid Howells if (ret < 0) { 730e87b03f5SDavid Howells _leave(" = %zd", ret); 73131143d5dSDavid Howells return ret; 73231143d5dSDavid Howells } 73331143d5dSDavid Howells 734dc255730SMarc Dionne start += ret; 73531143d5dSDavid Howells 73631143d5dSDavid Howells cond_resched(); 737e87b03f5SDavid Howells } while (wbc->nr_to_write > 0); 73831143d5dSDavid Howells 739e87b03f5SDavid Howells *_next = start; 740e87b03f5SDavid Howells _leave(" = 0 [%llx]", *_next); 74131143d5dSDavid Howells return 0; 74231143d5dSDavid Howells } 74331143d5dSDavid Howells 74431143d5dSDavid Howells /* 74531143d5dSDavid Howells * write some of the pending data back to the server 74631143d5dSDavid Howells */ 74731143d5dSDavid Howells int afs_writepages(struct address_space *mapping, 74831143d5dSDavid Howells struct writeback_control *wbc) 74931143d5dSDavid Howells { 750ec0fa0b6SDavid Howells struct afs_vnode *vnode = AFS_FS_I(mapping->host); 751e87b03f5SDavid Howells loff_t start, next; 75231143d5dSDavid Howells int ret; 75331143d5dSDavid Howells 75431143d5dSDavid Howells _enter(""); 75531143d5dSDavid Howells 756ec0fa0b6SDavid Howells /* We have to be careful as we can end up racing with setattr() 757ec0fa0b6SDavid Howells * truncating the pagecache since the caller doesn't take a lock here 758ec0fa0b6SDavid Howells * to prevent it. 759ec0fa0b6SDavid Howells */ 760ec0fa0b6SDavid Howells if (wbc->sync_mode == WB_SYNC_ALL) 761ec0fa0b6SDavid Howells down_read(&vnode->validate_lock); 762ec0fa0b6SDavid Howells else if (!down_read_trylock(&vnode->validate_lock)) 763ec0fa0b6SDavid Howells return 0; 764ec0fa0b6SDavid Howells 76531143d5dSDavid Howells if (wbc->range_cyclic) { 766e87b03f5SDavid Howells start = mapping->writeback_index * PAGE_SIZE; 767e87b03f5SDavid Howells ret = afs_writepages_region(mapping, wbc, start, LLONG_MAX, &next); 768afe69498STom Rix if (ret == 0) { 769e87b03f5SDavid Howells mapping->writeback_index = next / PAGE_SIZE; 770afe69498STom Rix if (start > 0 && wbc->nr_to_write > 0) { 771afe69498STom Rix ret = afs_writepages_region(mapping, wbc, 0, 772afe69498STom Rix start, &next); 773afe69498STom Rix if (ret == 0) 774afe69498STom Rix mapping->writeback_index = 775afe69498STom Rix next / PAGE_SIZE; 776afe69498STom Rix } 777afe69498STom Rix } 77831143d5dSDavid Howells } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { 779e87b03f5SDavid Howells ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next); 780afe69498STom Rix if (wbc->nr_to_write > 0 && ret == 0) 7815a972474SDavid Howells mapping->writeback_index = next / PAGE_SIZE; 78231143d5dSDavid Howells } else { 783e87b03f5SDavid Howells ret = afs_writepages_region(mapping, wbc, 784e87b03f5SDavid Howells wbc->range_start, wbc->range_end, &next); 78531143d5dSDavid Howells } 78631143d5dSDavid Howells 787ec0fa0b6SDavid Howells up_read(&vnode->validate_lock); 78831143d5dSDavid Howells _leave(" = %d", ret); 78931143d5dSDavid Howells return ret; 79031143d5dSDavid Howells } 79131143d5dSDavid Howells 79231143d5dSDavid Howells /* 79331143d5dSDavid Howells * write to an AFS file 79431143d5dSDavid Howells */ 79550b5551dSAl Viro ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) 79631143d5dSDavid Howells { 797496ad9aaSAl Viro struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); 7983978d816SDavid Howells struct afs_file *af = iocb->ki_filp->private_data; 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 8143978d816SDavid Howells result = afs_validate(vnode, af->key); 8153978d816SDavid Howells if (result < 0) 8163978d816SDavid Howells return result; 8173978d816SDavid Howells 81850b5551dSAl Viro result = generic_file_write_iter(iocb, from); 81931143d5dSDavid Howells 82031143d5dSDavid Howells _leave(" = %zd", result); 82131143d5dSDavid Howells return result; 82231143d5dSDavid Howells } 82331143d5dSDavid Howells 82431143d5dSDavid Howells /* 82531143d5dSDavid Howells * flush any dirty pages for this process, and check for write errors. 82631143d5dSDavid Howells * - the return status from this call provides a reliable indication of 82731143d5dSDavid Howells * whether any write errors occurred for this process. 82831143d5dSDavid Howells */ 82902c24a82SJosef Bacik int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 83031143d5dSDavid Howells { 8313978d816SDavid Howells struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); 8323978d816SDavid Howells struct afs_file *af = file->private_data; 8333978d816SDavid Howells int ret; 83431143d5dSDavid Howells 8353b6492dfSDavid Howells _enter("{%llx:%llu},{n=%pD},%d", 8363c981bfcSAl Viro vnode->fid.vid, vnode->fid.vnode, file, 83731143d5dSDavid Howells datasync); 83831143d5dSDavid Howells 8393978d816SDavid Howells ret = afs_validate(vnode, af->key); 8403978d816SDavid Howells if (ret < 0) 8413978d816SDavid Howells return ret; 8423978d816SDavid Howells 8434343d008SDavid Howells return file_write_and_wait_range(file, start, end); 84431143d5dSDavid Howells } 8459b3f26c9SDavid Howells 8469b3f26c9SDavid Howells /* 8479b3f26c9SDavid Howells * notification that a previously read-only page is about to become writable 8489b3f26c9SDavid Howells * - if it returns an error, the caller will deliver a bus error signal 8499b3f26c9SDavid Howells */ 8500722f186SSouptick Joarder vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) 8519b3f26c9SDavid Howells { 852490e016fSMatthew Wilcox (Oracle) struct folio *folio = page_folio(vmf->page); 8531cf7a151SDavid Howells struct file *file = vmf->vma->vm_file; 8541cf7a151SDavid Howells struct inode *inode = file_inode(file); 8551cf7a151SDavid Howells struct afs_vnode *vnode = AFS_FS_I(inode); 8563978d816SDavid Howells struct afs_file *af = file->private_data; 8571cf7a151SDavid Howells unsigned long priv; 8589620ad86SMatthew Wilcox (Oracle) vm_fault_t ret = VM_FAULT_RETRY; 8599b3f26c9SDavid Howells 860*78525c74SDavid Howells _enter("{{%llx:%llu}},{%lx}", vnode->fid.vid, vnode->fid.vnode, folio_index(folio)); 8619b3f26c9SDavid Howells 8623978d816SDavid Howells afs_validate(vnode, af->key); 8633978d816SDavid Howells 8641cf7a151SDavid Howells sb_start_pagefault(inode->i_sb); 8651cf7a151SDavid Howells 8661cf7a151SDavid Howells /* Wait for the page to be written to the cache before we allow it to 8671cf7a151SDavid Howells * be modified. We then assume the entire page will need writing back. 8681cf7a151SDavid Howells */ 869630f5ddaSDavid Howells #ifdef CONFIG_AFS_FSCACHE 870*78525c74SDavid Howells if (folio_test_fscache(folio) && 871*78525c74SDavid Howells folio_wait_fscache_killable(folio) < 0) 8729620ad86SMatthew Wilcox (Oracle) goto out; 873630f5ddaSDavid Howells #endif 8749b3f26c9SDavid Howells 875490e016fSMatthew Wilcox (Oracle) if (folio_wait_writeback_killable(folio)) 8769620ad86SMatthew Wilcox (Oracle) goto out; 8771cf7a151SDavid Howells 878*78525c74SDavid Howells if (folio_lock_killable(folio) < 0) 8799620ad86SMatthew Wilcox (Oracle) goto out; 8801cf7a151SDavid Howells 881*78525c74SDavid Howells /* We mustn't change folio->private until writeback is complete as that 8821cf7a151SDavid Howells * details the portion of the page we need to write back and we might 8831cf7a151SDavid Howells * need to redirty the page if there's a problem. 8841cf7a151SDavid Howells */ 885490e016fSMatthew Wilcox (Oracle) if (folio_wait_writeback_killable(folio) < 0) { 886490e016fSMatthew Wilcox (Oracle) folio_unlock(folio); 8879620ad86SMatthew Wilcox (Oracle) goto out; 8885cbf0398SDavid Howells } 8891cf7a151SDavid Howells 890*78525c74SDavid Howells priv = afs_folio_dirty(folio, 0, folio_size(folio)); 891*78525c74SDavid Howells priv = afs_folio_dirty_mmapped(priv); 892*78525c74SDavid Howells if (folio_test_private(folio)) { 893*78525c74SDavid Howells folio_change_private(folio, (void *)priv); 894*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite+"), folio); 895e87b03f5SDavid Howells } else { 896*78525c74SDavid Howells folio_attach_private(folio, (void *)priv); 897*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite"), folio); 898e87b03f5SDavid Howells } 899bb413489SDavid Howells file_update_time(file); 9001cf7a151SDavid Howells 9019620ad86SMatthew Wilcox (Oracle) ret = VM_FAULT_LOCKED; 9029620ad86SMatthew Wilcox (Oracle) out: 9031cf7a151SDavid Howells sb_end_pagefault(inode->i_sb); 9049620ad86SMatthew Wilcox (Oracle) return ret; 9059b3f26c9SDavid Howells } 9064343d008SDavid Howells 9074343d008SDavid Howells /* 9084343d008SDavid Howells * Prune the keys cached for writeback. The caller must hold vnode->wb_lock. 9094343d008SDavid Howells */ 9104343d008SDavid Howells void afs_prune_wb_keys(struct afs_vnode *vnode) 9114343d008SDavid Howells { 9124343d008SDavid Howells LIST_HEAD(graveyard); 9134343d008SDavid Howells struct afs_wb_key *wbk, *tmp; 9144343d008SDavid Howells 9154343d008SDavid Howells /* Discard unused keys */ 9164343d008SDavid Howells spin_lock(&vnode->wb_lock); 9174343d008SDavid Howells 9184343d008SDavid Howells if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && 9194343d008SDavid Howells !mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { 9204343d008SDavid Howells list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { 9214343d008SDavid Howells if (refcount_read(&wbk->usage) == 1) 9224343d008SDavid Howells list_move(&wbk->vnode_link, &graveyard); 9234343d008SDavid Howells } 9244343d008SDavid Howells } 9254343d008SDavid Howells 9264343d008SDavid Howells spin_unlock(&vnode->wb_lock); 9274343d008SDavid Howells 9284343d008SDavid Howells while (!list_empty(&graveyard)) { 9294343d008SDavid Howells wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); 9304343d008SDavid Howells list_del(&wbk->vnode_link); 9314343d008SDavid Howells afs_put_wb_key(wbk); 9324343d008SDavid Howells } 9334343d008SDavid Howells } 9344343d008SDavid Howells 9354343d008SDavid Howells /* 9364343d008SDavid Howells * Clean up a page during invalidation. 9374343d008SDavid Howells */ 938*78525c74SDavid Howells int afs_launder_page(struct page *subpage) 9394343d008SDavid Howells { 940*78525c74SDavid Howells struct folio *folio = page_folio(subpage); 941*78525c74SDavid Howells struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio)); 942bd80d8a8SDavid Howells struct iov_iter iter; 943bd80d8a8SDavid Howells struct bio_vec bv[1]; 9444343d008SDavid Howells unsigned long priv; 9454343d008SDavid Howells unsigned int f, t; 9464343d008SDavid Howells int ret = 0; 9474343d008SDavid Howells 948*78525c74SDavid Howells _enter("{%lx}", folio_index(folio)); 9494343d008SDavid Howells 950*78525c74SDavid Howells priv = (unsigned long)folio_get_private(folio); 951*78525c74SDavid Howells if (folio_clear_dirty_for_io(folio)) { 9524343d008SDavid Howells f = 0; 953*78525c74SDavid Howells t = folio_size(folio); 954*78525c74SDavid Howells if (folio_test_private(folio)) { 955*78525c74SDavid Howells f = afs_folio_dirty_from(folio, priv); 956*78525c74SDavid Howells t = afs_folio_dirty_to(folio, priv); 9574343d008SDavid Howells } 9584343d008SDavid Howells 959*78525c74SDavid Howells bv[0].bv_page = &folio->page; 960bd80d8a8SDavid Howells bv[0].bv_offset = f; 961bd80d8a8SDavid Howells bv[0].bv_len = t - f; 962bd80d8a8SDavid Howells iov_iter_bvec(&iter, WRITE, bv, 1, bv[0].bv_len); 963bd80d8a8SDavid Howells 964*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("launder"), folio); 965*78525c74SDavid Howells ret = afs_store_data(vnode, &iter, folio_pos(folio) + f, true); 9664343d008SDavid Howells } 9674343d008SDavid Howells 968*78525c74SDavid Howells trace_afs_folio_dirty(vnode, tracepoint_string("laundered"), folio); 969*78525c74SDavid Howells folio_detach_private(folio); 970*78525c74SDavid Howells folio_wait_fscache(folio); 9714343d008SDavid Howells return ret; 97231143d5dSDavid Howells } 973