| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* AFS filesystem file handling |
| * |
| * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/gfp.h> |
| #include <linux/task_io_accounting_ops.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/netfs.h> |
| #include "internal.h" |
| |
| static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); |
| static int afs_symlink_read_folio(struct file *file, struct folio *folio); |
| |
| static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter); |
| static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t len, unsigned int flags); |
| static void afs_vm_open(struct vm_area_struct *area); |
| static void afs_vm_close(struct vm_area_struct *area); |
| static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff); |
| |
| const struct file_operations afs_file_operations = { |
| .open = afs_open, |
| .release = afs_release, |
| .llseek = generic_file_llseek, |
| .read_iter = afs_file_read_iter, |
| .write_iter = netfs_file_write_iter, |
| .mmap = afs_file_mmap, |
| .splice_read = afs_file_splice_read, |
| .splice_write = iter_file_splice_write, |
| .fsync = afs_fsync, |
| .lock = afs_lock, |
| .flock = afs_flock, |
| }; |
| |
| const struct inode_operations afs_file_inode_operations = { |
| .getattr = afs_getattr, |
| .setattr = afs_setattr, |
| .permission = afs_permission, |
| }; |
| |
| const struct address_space_operations afs_file_aops = { |
| .direct_IO = noop_direct_IO, |
| .read_folio = netfs_read_folio, |
| .readahead = netfs_readahead, |
| .dirty_folio = netfs_dirty_folio, |
| .release_folio = netfs_release_folio, |
| .invalidate_folio = netfs_invalidate_folio, |
| .migrate_folio = filemap_migrate_folio, |
| .writepages = afs_writepages, |
| }; |
| |
| const struct address_space_operations afs_symlink_aops = { |
| .read_folio = afs_symlink_read_folio, |
| .release_folio = netfs_release_folio, |
| .invalidate_folio = netfs_invalidate_folio, |
| .migrate_folio = filemap_migrate_folio, |
| }; |
| |
| static const struct vm_operations_struct afs_vm_ops = { |
| .open = afs_vm_open, |
| .close = afs_vm_close, |
| .fault = filemap_fault, |
| .map_pages = afs_vm_map_pages, |
| .page_mkwrite = afs_page_mkwrite, |
| }; |
| |
| /* |
| * Discard a pin on a writeback key. |
| */ |
| void afs_put_wb_key(struct afs_wb_key *wbk) |
| { |
| if (wbk && refcount_dec_and_test(&wbk->usage)) { |
| key_put(wbk->key); |
| kfree(wbk); |
| } |
| } |
| |
| /* |
| * Cache key for writeback. |
| */ |
| int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) |
| { |
| struct afs_wb_key *wbk, *p; |
| |
| wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); |
| if (!wbk) |
| return -ENOMEM; |
| refcount_set(&wbk->usage, 2); |
| wbk->key = af->key; |
| |
| spin_lock(&vnode->wb_lock); |
| list_for_each_entry(p, &vnode->wb_keys, vnode_link) { |
| if (p->key == wbk->key) |
| goto found; |
| } |
| |
| key_get(wbk->key); |
| list_add_tail(&wbk->vnode_link, &vnode->wb_keys); |
| spin_unlock(&vnode->wb_lock); |
| af->wb = wbk; |
| return 0; |
| |
| found: |
| refcount_inc(&p->usage); |
| spin_unlock(&vnode->wb_lock); |
| af->wb = p; |
| kfree(wbk); |
| return 0; |
| } |
| |
| /* |
| * open an AFS file or directory and attach a key to it |
| */ |
| int afs_open(struct inode *inode, struct file *file) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(inode); |
| struct afs_file *af; |
| struct key *key; |
| int ret; |
| |
| _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
| |
| key = afs_request_key(vnode->volume->cell); |
| if (IS_ERR(key)) { |
| ret = PTR_ERR(key); |
| goto error; |
| } |
| |
| af = kzalloc(sizeof(*af), GFP_KERNEL); |
| if (!af) { |
| ret = -ENOMEM; |
| goto error_key; |
| } |
| af->key = key; |
| |
| ret = afs_validate(vnode, key); |
| if (ret < 0) |
| goto error_af; |
| |
| if (file->f_mode & FMODE_WRITE) { |
| ret = afs_cache_wb_key(vnode, af); |
| if (ret < 0) |
| goto error_af; |
| } |
| |
| if (file->f_flags & O_TRUNC) |
| set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); |
| |
| fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE); |
| |
| file->private_data = af; |
| _leave(" = 0"); |
| return 0; |
| |
| error_af: |
| kfree(af); |
| error_key: |
| key_put(key); |
| error: |
| _leave(" = %d", ret); |
| return ret; |
| } |
| |
| /* |
| * release an AFS file or directory and discard its key |
| */ |
| int afs_release(struct inode *inode, struct file *file) |
| { |
| struct afs_vnode_cache_aux aux; |
| struct afs_vnode *vnode = AFS_FS_I(inode); |
| struct afs_file *af = file->private_data; |
| loff_t i_size; |
| int ret = 0; |
| |
| _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
| |
| if ((file->f_mode & FMODE_WRITE)) |
| ret = vfs_fsync(file, 0); |
| |
| file->private_data = NULL; |
| if (af->wb) |
| afs_put_wb_key(af->wb); |
| |
| if ((file->f_mode & FMODE_WRITE)) { |
| i_size = i_size_read(&vnode->netfs.inode); |
| afs_set_cache_aux(vnode, &aux); |
| fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size); |
| } else { |
| fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL); |
| } |
| |
| key_put(af->key); |
| kfree(af); |
| afs_prune_wb_keys(vnode); |
| _leave(" = %d", ret); |
| return ret; |
| } |
| |
| /* |
| * Allocate a new read record. |
| */ |
| struct afs_read *afs_alloc_read(gfp_t gfp) |
| { |
| struct afs_read *req; |
| |
| req = kzalloc(sizeof(struct afs_read), gfp); |
| if (req) |
| refcount_set(&req->usage, 1); |
| |
| return req; |
| } |
| |
| /* |
| * Dispose of a ref to a read record. |
| */ |
| void afs_put_read(struct afs_read *req) |
| { |
| if (refcount_dec_and_test(&req->usage)) { |
| if (req->cleanup) |
| req->cleanup(req); |
| key_put(req->key); |
| kfree(req); |
| } |
| } |
| |
| static void afs_fetch_data_notify(struct afs_operation *op) |
| { |
| struct afs_read *req = op->fetch.req; |
| struct netfs_io_subrequest *subreq = req->subreq; |
| int error = afs_op_error(op); |
| |
| req->error = error; |
| if (subreq) { |
| if (subreq->rreq->origin != NETFS_DIO_READ) |
| __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); |
| netfs_subreq_terminated(subreq, error ?: req->actual_len, false); |
| req->subreq = NULL; |
| } else if (req->done) { |
| req->done(req); |
| } |
| } |
| |
| static void afs_fetch_data_success(struct afs_operation *op) |
| { |
| struct afs_vnode *vnode = op->file[0].vnode; |
| |
| _enter("op=%08x", op->debug_id); |
| afs_vnode_commit_status(op, &op->file[0]); |
| afs_stat_v(vnode, n_fetches); |
| atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes); |
| afs_fetch_data_notify(op); |
| } |
| |
| static void afs_fetch_data_put(struct afs_operation *op) |
| { |
| op->fetch.req->error = afs_op_error(op); |
| afs_put_read(op->fetch.req); |
| } |
| |
| static const struct afs_operation_ops afs_fetch_data_operation = { |
| .issue_afs_rpc = afs_fs_fetch_data, |
| .issue_yfs_rpc = yfs_fs_fetch_data, |
| .success = afs_fetch_data_success, |
| .aborted = afs_check_for_remote_deletion, |
| .failed = afs_fetch_data_notify, |
| .put = afs_fetch_data_put, |
| }; |
| |
| /* |
| * Fetch file data from the volume. |
| */ |
| int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) |
| { |
| struct afs_operation *op; |
| |
| _enter("%s{%llx:%llu.%u},%x,,,", |
| vnode->volume->name, |
| vnode->fid.vid, |
| vnode->fid.vnode, |
| vnode->fid.unique, |
| key_serial(req->key)); |
| |
| op = afs_alloc_operation(req->key, vnode->volume); |
| if (IS_ERR(op)) { |
| if (req->subreq) |
| netfs_subreq_terminated(req->subreq, PTR_ERR(op), false); |
| return PTR_ERR(op); |
| } |
| |
| afs_op_set_vnode(op, 0, vnode); |
| |
| op->fetch.req = afs_get_read(req); |
| op->ops = &afs_fetch_data_operation; |
| return afs_do_sync_operation(op); |
| } |
| |
| static void afs_issue_read(struct netfs_io_subrequest *subreq) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode); |
| struct afs_read *fsreq; |
| |
| fsreq = afs_alloc_read(GFP_NOFS); |
| if (!fsreq) |
| return netfs_subreq_terminated(subreq, -ENOMEM, false); |
| |
| fsreq->subreq = subreq; |
| fsreq->pos = subreq->start + subreq->transferred; |
| fsreq->len = subreq->len - subreq->transferred; |
| fsreq->key = key_get(subreq->rreq->netfs_priv); |
| fsreq->vnode = vnode; |
| fsreq->iter = &subreq->io_iter; |
| |
| afs_fetch_data(fsreq->vnode, fsreq); |
| afs_put_read(fsreq); |
| } |
| |
| static int afs_symlink_read_folio(struct file *file, struct folio *folio) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host); |
| struct afs_read *fsreq; |
| int ret; |
| |
| fsreq = afs_alloc_read(GFP_NOFS); |
| if (!fsreq) |
| return -ENOMEM; |
| |
| fsreq->pos = folio_pos(folio); |
| fsreq->len = folio_size(folio); |
| fsreq->vnode = vnode; |
| fsreq->iter = &fsreq->def_iter; |
| iov_iter_xarray(&fsreq->def_iter, ITER_DEST, &folio->mapping->i_pages, |
| fsreq->pos, fsreq->len); |
| |
| ret = afs_fetch_data(fsreq->vnode, fsreq); |
| if (ret == 0) |
| folio_mark_uptodate(folio); |
| folio_unlock(folio); |
| return ret; |
| } |
| |
| static int afs_init_request(struct netfs_io_request *rreq, struct file *file) |
| { |
| if (file) |
| rreq->netfs_priv = key_get(afs_file_key(file)); |
| rreq->rsize = 256 * 1024; |
| rreq->wsize = 256 * 1024 * 1024; |
| return 0; |
| } |
| |
| static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len, |
| struct folio **foliop, void **_fsdata) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
| |
| return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0; |
| } |
| |
| static void afs_free_request(struct netfs_io_request *rreq) |
| { |
| key_put(rreq->netfs_priv); |
| afs_put_wb_key(rreq->netfs_priv2); |
| } |
| |
| static void afs_update_i_size(struct inode *inode, loff_t new_i_size) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(inode); |
| loff_t i_size; |
| |
| write_seqlock(&vnode->cb_lock); |
| i_size = i_size_read(&vnode->netfs.inode); |
| if (new_i_size > i_size) { |
| i_size_write(&vnode->netfs.inode, new_i_size); |
| inode_set_bytes(&vnode->netfs.inode, new_i_size); |
| } |
| write_sequnlock(&vnode->cb_lock); |
| fscache_update_cookie(afs_vnode_cache(vnode), NULL, &new_i_size); |
| } |
| |
| static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(wreq->inode); |
| |
| afs_invalidate_cache(vnode, 0); |
| } |
| |
| const struct netfs_request_ops afs_req_ops = { |
| .init_request = afs_init_request, |
| .free_request = afs_free_request, |
| .check_write_begin = afs_check_write_begin, |
| .issue_read = afs_issue_read, |
| .update_i_size = afs_update_i_size, |
| .invalidate_cache = afs_netfs_invalidate_cache, |
| .begin_writeback = afs_begin_writeback, |
| .prepare_write = afs_prepare_write, |
| .issue_write = afs_issue_write, |
| }; |
| |
| static void afs_add_open_mmap(struct afs_vnode *vnode) |
| { |
| if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) { |
| down_write(&vnode->volume->open_mmaps_lock); |
| |
| if (list_empty(&vnode->cb_mmap_link)) |
| list_add_tail(&vnode->cb_mmap_link, &vnode->volume->open_mmaps); |
| |
| up_write(&vnode->volume->open_mmaps_lock); |
| } |
| } |
| |
| static void afs_drop_open_mmap(struct afs_vnode *vnode) |
| { |
| if (atomic_add_unless(&vnode->cb_nr_mmap, -1, 1)) |
| return; |
| |
| down_write(&vnode->volume->open_mmaps_lock); |
| |
| read_seqlock_excl(&vnode->cb_lock); |
| // the only place where ->cb_nr_mmap may hit 0 |
| // see __afs_break_callback() for the other side... |
| if (atomic_dec_and_test(&vnode->cb_nr_mmap)) |
| list_del_init(&vnode->cb_mmap_link); |
| read_sequnlock_excl(&vnode->cb_lock); |
| |
| up_write(&vnode->volume->open_mmaps_lock); |
| flush_work(&vnode->cb_work); |
| } |
| |
| /* |
| * Handle setting up a memory mapping on an AFS file. |
| */ |
| static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
| int ret; |
| |
| afs_add_open_mmap(vnode); |
| |
| ret = generic_file_mmap(file, vma); |
| if (ret == 0) |
| vma->vm_ops = &afs_vm_ops; |
| else |
| afs_drop_open_mmap(vnode); |
| return ret; |
| } |
| |
| static void afs_vm_open(struct vm_area_struct *vma) |
| { |
| afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file))); |
| } |
| |
| static void afs_vm_close(struct vm_area_struct *vma) |
| { |
| afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file))); |
| } |
| |
| static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff) |
| { |
| struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file)); |
| |
| if (afs_check_validity(vnode)) |
| return filemap_map_pages(vmf, start_pgoff, end_pgoff); |
| return 0; |
| } |
| |
| static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
| { |
| struct inode *inode = file_inode(iocb->ki_filp); |
| struct afs_vnode *vnode = AFS_FS_I(inode); |
| struct afs_file *af = iocb->ki_filp->private_data; |
| ssize_t ret; |
| |
| if (iocb->ki_flags & IOCB_DIRECT) |
| return netfs_unbuffered_read_iter(iocb, iter); |
| |
| ret = netfs_start_io_read(inode); |
| if (ret < 0) |
| return ret; |
| ret = afs_validate(vnode, af->key); |
| if (ret == 0) |
| ret = filemap_read(iocb, iter, 0); |
| netfs_end_io_read(inode); |
| return ret; |
| } |
| |
| static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t len, unsigned int flags) |
| { |
| struct inode *inode = file_inode(in); |
| struct afs_vnode *vnode = AFS_FS_I(inode); |
| struct afs_file *af = in->private_data; |
| ssize_t ret; |
| |
| ret = netfs_start_io_read(inode); |
| if (ret < 0) |
| return ret; |
| ret = afs_validate(vnode, af->key); |
| if (ret == 0) |
| ret = filemap_splice_read(in, ppos, pipe, len, flags); |
| netfs_end_io_read(inode); |
| return ret; |
| } |