1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* AFS filesystem file handling
4 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
12 #include <linux/pagemap.h>
13 #include <linux/writeback.h>
14 #include <linux/gfp.h>
15 #include <linux/task_io_accounting_ops.h>
17 #include <linux/swap.h>
18 #include <linux/netfs.h>
21 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
22 static int afs_symlink_read_folio(struct file *file, struct folio *folio);
23 static void afs_invalidate_folio(struct folio *folio, size_t offset,
25 static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags);
27 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
28 static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
29 struct pipe_inode_info *pipe,
30 size_t len, unsigned int flags);
31 static void afs_vm_open(struct vm_area_struct *area);
32 static void afs_vm_close(struct vm_area_struct *area);
33 static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff);
35 const struct file_operations afs_file_operations = {
37 .release = afs_release,
38 .llseek = generic_file_llseek,
39 .read_iter = afs_file_read_iter,
40 .write_iter = afs_file_write,
41 .mmap = afs_file_mmap,
42 .splice_read = afs_file_splice_read,
43 .splice_write = iter_file_splice_write,
49 const struct inode_operations afs_file_inode_operations = {
50 .getattr = afs_getattr,
51 .setattr = afs_setattr,
52 .permission = afs_permission,
55 const struct address_space_operations afs_file_aops = {
56 .read_folio = netfs_read_folio,
57 .readahead = netfs_readahead,
58 .dirty_folio = afs_dirty_folio,
59 .launder_folio = afs_launder_folio,
60 .release_folio = afs_release_folio,
61 .invalidate_folio = afs_invalidate_folio,
62 .write_begin = afs_write_begin,
63 .write_end = afs_write_end,
64 .writepages = afs_writepages,
65 .migrate_folio = filemap_migrate_folio,
68 const struct address_space_operations afs_symlink_aops = {
69 .read_folio = afs_symlink_read_folio,
70 .release_folio = afs_release_folio,
71 .invalidate_folio = afs_invalidate_folio,
72 .migrate_folio = filemap_migrate_folio,
75 static const struct vm_operations_struct afs_vm_ops = {
77 .close = afs_vm_close,
78 .fault = filemap_fault,
79 .map_pages = afs_vm_map_pages,
80 .page_mkwrite = afs_page_mkwrite,
84 * Discard a pin on a writeback key.
86 void afs_put_wb_key(struct afs_wb_key *wbk)
88 if (wbk && refcount_dec_and_test(&wbk->usage)) {
95 * Cache key for writeback.
97 int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
99 struct afs_wb_key *wbk, *p;
101 wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
104 refcount_set(&wbk->usage, 2);
107 spin_lock(&vnode->wb_lock);
108 list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
109 if (p->key == wbk->key)
114 list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
115 spin_unlock(&vnode->wb_lock);
120 refcount_inc(&p->usage);
121 spin_unlock(&vnode->wb_lock);
128 * open an AFS file or directory and attach a key to it
130 int afs_open(struct inode *inode, struct file *file)
132 struct afs_vnode *vnode = AFS_FS_I(inode);
137 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
139 key = afs_request_key(vnode->volume->cell);
145 af = kzalloc(sizeof(*af), GFP_KERNEL);
152 ret = afs_validate(vnode, key);
156 if (file->f_mode & FMODE_WRITE) {
157 ret = afs_cache_wb_key(vnode, af);
162 if (file->f_flags & O_TRUNC)
163 set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
165 fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE);
167 file->private_data = af;
176 _leave(" = %d", ret);
181 * release an AFS file or directory and discard its key
183 int afs_release(struct inode *inode, struct file *file)
185 struct afs_vnode_cache_aux aux;
186 struct afs_vnode *vnode = AFS_FS_I(inode);
187 struct afs_file *af = file->private_data;
191 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
193 if ((file->f_mode & FMODE_WRITE))
194 ret = vfs_fsync(file, 0);
196 file->private_data = NULL;
198 afs_put_wb_key(af->wb);
200 if ((file->f_mode & FMODE_WRITE)) {
201 i_size = i_size_read(&vnode->netfs.inode);
202 afs_set_cache_aux(vnode, &aux);
203 fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size);
205 fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
210 afs_prune_wb_keys(vnode);
211 _leave(" = %d", ret);
216 * Allocate a new read record.
218 struct afs_read *afs_alloc_read(gfp_t gfp)
220 struct afs_read *req;
222 req = kzalloc(sizeof(struct afs_read), gfp);
224 refcount_set(&req->usage, 1);
230 * Dispose of a ref to a read record.
232 void afs_put_read(struct afs_read *req)
234 if (refcount_dec_and_test(&req->usage)) {
242 static void afs_fetch_data_notify(struct afs_operation *op)
244 struct afs_read *req = op->fetch.req;
245 struct netfs_io_subrequest *subreq = req->subreq;
246 int error = afs_op_error(op);
250 __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
251 netfs_subreq_terminated(subreq, error ?: req->actual_len, false);
253 } else if (req->done) {
258 static void afs_fetch_data_success(struct afs_operation *op)
260 struct afs_vnode *vnode = op->file[0].vnode;
262 _enter("op=%08x", op->debug_id);
263 afs_vnode_commit_status(op, &op->file[0]);
264 afs_stat_v(vnode, n_fetches);
265 atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes);
266 afs_fetch_data_notify(op);
269 static void afs_fetch_data_put(struct afs_operation *op)
271 op->fetch.req->error = afs_op_error(op);
272 afs_put_read(op->fetch.req);
275 static const struct afs_operation_ops afs_fetch_data_operation = {
276 .issue_afs_rpc = afs_fs_fetch_data,
277 .issue_yfs_rpc = yfs_fs_fetch_data,
278 .success = afs_fetch_data_success,
279 .aborted = afs_check_for_remote_deletion,
280 .failed = afs_fetch_data_notify,
281 .put = afs_fetch_data_put,
285 * Fetch file data from the volume.
287 int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
289 struct afs_operation *op;
291 _enter("%s{%llx:%llu.%u},%x,,,",
296 key_serial(req->key));
298 op = afs_alloc_operation(req->key, vnode->volume);
301 netfs_subreq_terminated(req->subreq, PTR_ERR(op), false);
305 afs_op_set_vnode(op, 0, vnode);
307 op->fetch.req = afs_get_read(req);
308 op->ops = &afs_fetch_data_operation;
309 return afs_do_sync_operation(op);
312 static void afs_issue_read(struct netfs_io_subrequest *subreq)
314 struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
315 struct afs_read *fsreq;
317 fsreq = afs_alloc_read(GFP_NOFS);
319 return netfs_subreq_terminated(subreq, -ENOMEM, false);
321 fsreq->subreq = subreq;
322 fsreq->pos = subreq->start + subreq->transferred;
323 fsreq->len = subreq->len - subreq->transferred;
324 fsreq->key = key_get(subreq->rreq->netfs_priv);
325 fsreq->vnode = vnode;
326 fsreq->iter = &fsreq->def_iter;
328 iov_iter_xarray(&fsreq->def_iter, ITER_DEST,
329 &fsreq->vnode->netfs.inode.i_mapping->i_pages,
330 fsreq->pos, fsreq->len);
332 afs_fetch_data(fsreq->vnode, fsreq);
336 static int afs_symlink_read_folio(struct file *file, struct folio *folio)
338 struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host);
339 struct afs_read *fsreq;
342 fsreq = afs_alloc_read(GFP_NOFS);
346 fsreq->pos = folio_pos(folio);
347 fsreq->len = folio_size(folio);
348 fsreq->vnode = vnode;
349 fsreq->iter = &fsreq->def_iter;
350 iov_iter_xarray(&fsreq->def_iter, ITER_DEST, &folio->mapping->i_pages,
351 fsreq->pos, fsreq->len);
353 ret = afs_fetch_data(fsreq->vnode, fsreq);
355 folio_mark_uptodate(folio);
360 static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
362 rreq->netfs_priv = key_get(afs_file_key(file));
366 static int afs_begin_cache_operation(struct netfs_io_request *rreq)
368 #ifdef CONFIG_AFS_FSCACHE
369 struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
371 return fscache_begin_read_operation(&rreq->cache_resources,
372 afs_vnode_cache(vnode));
378 static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
379 struct folio **foliop, void **_fsdata)
381 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
383 return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
386 static void afs_free_request(struct netfs_io_request *rreq)
388 key_put(rreq->netfs_priv);
391 const struct netfs_request_ops afs_req_ops = {
392 .init_request = afs_init_request,
393 .free_request = afs_free_request,
394 .begin_cache_operation = afs_begin_cache_operation,
395 .check_write_begin = afs_check_write_begin,
396 .issue_read = afs_issue_read,
399 int afs_write_inode(struct inode *inode, struct writeback_control *wbc)
401 fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode)));
406 * Adjust the dirty region of the page on truncation or full invalidation,
407 * getting rid of the markers altogether if the region is entirely invalidated.
409 static void afs_invalidate_dirty(struct folio *folio, size_t offset,
412 struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
414 unsigned int f, t, end = offset + length;
416 priv = (unsigned long)folio_get_private(folio);
418 /* we clean up only if the entire page is being invalidated */
419 if (offset == 0 && length == folio_size(folio))
420 goto full_invalidate;
422 /* If the page was dirtied by page_mkwrite(), the PTE stays writable
423 * and we don't get another notification to tell us to expand it
426 if (afs_is_folio_dirty_mmapped(priv))
429 /* We may need to shorten the dirty region */
430 f = afs_folio_dirty_from(folio, priv);
431 t = afs_folio_dirty_to(folio, priv);
433 if (t <= offset || f >= end)
434 return; /* Doesn't overlap */
436 if (f < offset && t > end)
437 return; /* Splits the dirty region - just absorb it */
439 if (f >= offset && t <= end)
449 priv = afs_folio_dirty(folio, f, t);
450 folio_change_private(folio, (void *)priv);
451 trace_afs_folio_dirty(vnode, tracepoint_string("trunc"), folio);
455 trace_afs_folio_dirty(vnode, tracepoint_string("undirty"), folio);
456 folio_clear_dirty_for_io(folio);
458 trace_afs_folio_dirty(vnode, tracepoint_string("inval"), folio);
459 folio_detach_private(folio);
463 * invalidate part or all of a page
464 * - release a page and clean up its private data if offset is 0 (indicating
467 static void afs_invalidate_folio(struct folio *folio, size_t offset,
470 _enter("{%lu},%zu,%zu", folio->index, offset, length);
472 BUG_ON(!folio_test_locked(folio));
474 if (folio_get_private(folio))
475 afs_invalidate_dirty(folio, offset, length);
477 folio_wait_fscache(folio);
482 * release a page and clean up its private state if it's not busy
483 * - return true if the page can now be released, false if not
485 static bool afs_release_folio(struct folio *folio, gfp_t gfp)
487 struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
489 _enter("{{%llx:%llu}[%lu],%lx},%x",
490 vnode->fid.vid, vnode->fid.vnode, folio_index(folio), folio->flags,
493 /* deny if folio is being written to the cache and the caller hasn't
495 #ifdef CONFIG_AFS_FSCACHE
496 if (folio_test_fscache(folio)) {
497 if (current_is_kswapd() || !(gfp & __GFP_FS))
499 folio_wait_fscache(folio);
501 fscache_note_page_release(afs_vnode_cache(vnode));
504 if (folio_test_private(folio)) {
505 trace_afs_folio_dirty(vnode, tracepoint_string("rel"), folio);
506 folio_detach_private(folio);
509 /* Indicate that the folio can be released */
514 static void afs_add_open_mmap(struct afs_vnode *vnode)
516 if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
517 down_write(&vnode->volume->open_mmaps_lock);
519 if (list_empty(&vnode->cb_mmap_link))
520 list_add_tail(&vnode->cb_mmap_link, &vnode->volume->open_mmaps);
522 up_write(&vnode->volume->open_mmaps_lock);
526 static void afs_drop_open_mmap(struct afs_vnode *vnode)
528 if (!atomic_dec_and_test(&vnode->cb_nr_mmap))
531 down_write(&vnode->volume->open_mmaps_lock);
533 if (atomic_read(&vnode->cb_nr_mmap) == 0)
534 list_del_init(&vnode->cb_mmap_link);
536 up_write(&vnode->volume->open_mmaps_lock);
537 flush_work(&vnode->cb_work);
541 * Handle setting up a memory mapping on an AFS file.
543 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
545 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
548 afs_add_open_mmap(vnode);
550 ret = generic_file_mmap(file, vma);
552 vma->vm_ops = &afs_vm_ops;
554 afs_drop_open_mmap(vnode);
558 static void afs_vm_open(struct vm_area_struct *vma)
560 afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
563 static void afs_vm_close(struct vm_area_struct *vma)
565 afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
568 static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
570 struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file));
572 if (afs_check_validity(vnode))
573 return filemap_map_pages(vmf, start_pgoff, end_pgoff);
577 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
579 struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
580 struct afs_file *af = iocb->ki_filp->private_data;
583 ret = afs_validate(vnode, af->key);
587 return generic_file_read_iter(iocb, iter);
590 static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
591 struct pipe_inode_info *pipe,
592 size_t len, unsigned int flags)
594 struct afs_vnode *vnode = AFS_FS_I(file_inode(in));
595 struct afs_file *af = in->private_data;
598 ret = afs_validate(vnode, af->key);
602 return filemap_splice_read(in, ppos, pipe, len, flags);