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598 lines
14 KiB
598 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* AFS filesystem file handling |
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* |
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* Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
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* Written by David Howells ([email protected]) |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/fs.h> |
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#include <linux/pagemap.h> |
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#include <linux/writeback.h> |
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#include <linux/gfp.h> |
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#include <linux/task_io_accounting_ops.h> |
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#include <linux/mm.h> |
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#include <linux/swap.h> |
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#include <linux/netfs.h> |
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#include "internal.h" |
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static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); |
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static int afs_symlink_read_folio(struct file *file, struct folio *folio); |
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static void afs_invalidate_folio(struct folio *folio, size_t offset, |
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size_t length); |
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static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags); |
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static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter); |
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static void afs_vm_open(struct vm_area_struct *area); |
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static void afs_vm_close(struct vm_area_struct *area); |
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static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff); |
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const struct file_operations afs_file_operations = { |
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.open = afs_open, |
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.release = afs_release, |
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.llseek = generic_file_llseek, |
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.read_iter = afs_file_read_iter, |
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.write_iter = afs_file_write, |
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.mmap = afs_file_mmap, |
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.splice_read = generic_file_splice_read, |
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.splice_write = iter_file_splice_write, |
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.fsync = afs_fsync, |
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.lock = afs_lock, |
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.flock = afs_flock, |
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}; |
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const struct inode_operations afs_file_inode_operations = { |
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.getattr = afs_getattr, |
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.setattr = afs_setattr, |
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.permission = afs_permission, |
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}; |
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const struct address_space_operations afs_file_aops = { |
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.read_folio = netfs_read_folio, |
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.readahead = netfs_readahead, |
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.dirty_folio = afs_dirty_folio, |
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.launder_folio = afs_launder_folio, |
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.release_folio = afs_release_folio, |
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.invalidate_folio = afs_invalidate_folio, |
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.write_begin = afs_write_begin, |
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.write_end = afs_write_end, |
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.writepage = afs_writepage, |
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.writepages = afs_writepages, |
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}; |
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const struct address_space_operations afs_symlink_aops = { |
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.read_folio = afs_symlink_read_folio, |
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.release_folio = afs_release_folio, |
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.invalidate_folio = afs_invalidate_folio, |
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}; |
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static const struct vm_operations_struct afs_vm_ops = { |
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.open = afs_vm_open, |
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.close = afs_vm_close, |
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.fault = filemap_fault, |
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.map_pages = afs_vm_map_pages, |
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.page_mkwrite = afs_page_mkwrite, |
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}; |
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/* |
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* Discard a pin on a writeback key. |
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*/ |
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void afs_put_wb_key(struct afs_wb_key *wbk) |
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{ |
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if (wbk && refcount_dec_and_test(&wbk->usage)) { |
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key_put(wbk->key); |
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kfree(wbk); |
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} |
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} |
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/* |
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* Cache key for writeback. |
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*/ |
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int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) |
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{ |
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struct afs_wb_key *wbk, *p; |
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wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); |
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if (!wbk) |
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return -ENOMEM; |
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refcount_set(&wbk->usage, 2); |
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wbk->key = af->key; |
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spin_lock(&vnode->wb_lock); |
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list_for_each_entry(p, &vnode->wb_keys, vnode_link) { |
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if (p->key == wbk->key) |
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goto found; |
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} |
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key_get(wbk->key); |
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list_add_tail(&wbk->vnode_link, &vnode->wb_keys); |
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spin_unlock(&vnode->wb_lock); |
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af->wb = wbk; |
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return 0; |
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found: |
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refcount_inc(&p->usage); |
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spin_unlock(&vnode->wb_lock); |
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af->wb = p; |
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kfree(wbk); |
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return 0; |
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} |
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/* |
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* open an AFS file or directory and attach a key to it |
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*/ |
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int afs_open(struct inode *inode, struct file *file) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(inode); |
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struct afs_file *af; |
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struct key *key; |
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int ret; |
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_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
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key = afs_request_key(vnode->volume->cell); |
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if (IS_ERR(key)) { |
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ret = PTR_ERR(key); |
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goto error; |
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} |
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af = kzalloc(sizeof(*af), GFP_KERNEL); |
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if (!af) { |
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ret = -ENOMEM; |
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goto error_key; |
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} |
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af->key = key; |
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ret = afs_validate(vnode, key); |
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if (ret < 0) |
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goto error_af; |
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if (file->f_mode & FMODE_WRITE) { |
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ret = afs_cache_wb_key(vnode, af); |
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if (ret < 0) |
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goto error_af; |
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} |
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if (file->f_flags & O_TRUNC) |
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set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); |
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fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE); |
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file->private_data = af; |
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_leave(" = 0"); |
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return 0; |
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error_af: |
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kfree(af); |
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error_key: |
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key_put(key); |
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error: |
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_leave(" = %d", ret); |
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return ret; |
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} |
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/* |
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* release an AFS file or directory and discard its key |
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*/ |
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int afs_release(struct inode *inode, struct file *file) |
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{ |
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struct afs_vnode_cache_aux aux; |
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struct afs_vnode *vnode = AFS_FS_I(inode); |
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struct afs_file *af = file->private_data; |
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loff_t i_size; |
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int ret = 0; |
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_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
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if ((file->f_mode & FMODE_WRITE)) |
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ret = vfs_fsync(file, 0); |
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file->private_data = NULL; |
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if (af->wb) |
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afs_put_wb_key(af->wb); |
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if ((file->f_mode & FMODE_WRITE)) { |
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i_size = i_size_read(&vnode->netfs.inode); |
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afs_set_cache_aux(vnode, &aux); |
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fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size); |
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} else { |
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fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL); |
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} |
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key_put(af->key); |
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kfree(af); |
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afs_prune_wb_keys(vnode); |
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_leave(" = %d", ret); |
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return ret; |
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} |
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/* |
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* Allocate a new read record. |
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*/ |
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struct afs_read *afs_alloc_read(gfp_t gfp) |
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{ |
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struct afs_read *req; |
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req = kzalloc(sizeof(struct afs_read), gfp); |
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if (req) |
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refcount_set(&req->usage, 1); |
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return req; |
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} |
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/* |
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* Dispose of a ref to a read record. |
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*/ |
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void afs_put_read(struct afs_read *req) |
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{ |
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if (refcount_dec_and_test(&req->usage)) { |
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if (req->cleanup) |
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req->cleanup(req); |
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key_put(req->key); |
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kfree(req); |
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} |
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} |
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static void afs_fetch_data_notify(struct afs_operation *op) |
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{ |
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struct afs_read *req = op->fetch.req; |
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struct netfs_io_subrequest *subreq = req->subreq; |
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int error = op->error; |
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if (error == -ECONNABORTED) |
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error = afs_abort_to_error(op->ac.abort_code); |
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req->error = error; |
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if (subreq) { |
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__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); |
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netfs_subreq_terminated(subreq, error ?: req->actual_len, false); |
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req->subreq = NULL; |
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} else if (req->done) { |
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req->done(req); |
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} |
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} |
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static void afs_fetch_data_success(struct afs_operation *op) |
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{ |
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struct afs_vnode *vnode = op->file[0].vnode; |
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_enter("op=%08x", op->debug_id); |
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afs_vnode_commit_status(op, &op->file[0]); |
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afs_stat_v(vnode, n_fetches); |
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atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes); |
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afs_fetch_data_notify(op); |
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} |
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static void afs_fetch_data_put(struct afs_operation *op) |
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{ |
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op->fetch.req->error = op->error; |
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afs_put_read(op->fetch.req); |
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} |
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static const struct afs_operation_ops afs_fetch_data_operation = { |
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.issue_afs_rpc = afs_fs_fetch_data, |
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.issue_yfs_rpc = yfs_fs_fetch_data, |
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.success = afs_fetch_data_success, |
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.aborted = afs_check_for_remote_deletion, |
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.failed = afs_fetch_data_notify, |
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.put = afs_fetch_data_put, |
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}; |
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/* |
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* Fetch file data from the volume. |
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*/ |
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int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) |
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{ |
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struct afs_operation *op; |
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_enter("%s{%llx:%llu.%u},%x,,,", |
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vnode->volume->name, |
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vnode->fid.vid, |
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vnode->fid.vnode, |
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vnode->fid.unique, |
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key_serial(req->key)); |
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op = afs_alloc_operation(req->key, vnode->volume); |
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if (IS_ERR(op)) { |
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if (req->subreq) |
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netfs_subreq_terminated(req->subreq, PTR_ERR(op), false); |
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return PTR_ERR(op); |
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} |
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afs_op_set_vnode(op, 0, vnode); |
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op->fetch.req = afs_get_read(req); |
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op->ops = &afs_fetch_data_operation; |
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return afs_do_sync_operation(op); |
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} |
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static void afs_issue_read(struct netfs_io_subrequest *subreq) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode); |
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struct afs_read *fsreq; |
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fsreq = afs_alloc_read(GFP_NOFS); |
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if (!fsreq) |
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return netfs_subreq_terminated(subreq, -ENOMEM, false); |
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fsreq->subreq = subreq; |
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fsreq->pos = subreq->start + subreq->transferred; |
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fsreq->len = subreq->len - subreq->transferred; |
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fsreq->key = key_get(subreq->rreq->netfs_priv); |
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fsreq->vnode = vnode; |
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fsreq->iter = &fsreq->def_iter; |
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iov_iter_xarray(&fsreq->def_iter, READ, |
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&fsreq->vnode->netfs.inode.i_mapping->i_pages, |
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fsreq->pos, fsreq->len); |
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afs_fetch_data(fsreq->vnode, fsreq); |
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afs_put_read(fsreq); |
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} |
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static int afs_symlink_read_folio(struct file *file, struct folio *folio) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host); |
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struct afs_read *fsreq; |
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int ret; |
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fsreq = afs_alloc_read(GFP_NOFS); |
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if (!fsreq) |
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return -ENOMEM; |
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fsreq->pos = folio_pos(folio); |
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fsreq->len = folio_size(folio); |
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fsreq->vnode = vnode; |
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fsreq->iter = &fsreq->def_iter; |
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iov_iter_xarray(&fsreq->def_iter, READ, &folio->mapping->i_pages, |
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fsreq->pos, fsreq->len); |
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ret = afs_fetch_data(fsreq->vnode, fsreq); |
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if (ret == 0) |
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folio_mark_uptodate(folio); |
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folio_unlock(folio); |
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return ret; |
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} |
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static int afs_init_request(struct netfs_io_request *rreq, struct file *file) |
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{ |
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rreq->netfs_priv = key_get(afs_file_key(file)); |
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return 0; |
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} |
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static int afs_begin_cache_operation(struct netfs_io_request *rreq) |
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{ |
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#ifdef CONFIG_AFS_FSCACHE |
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struct afs_vnode *vnode = AFS_FS_I(rreq->inode); |
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return fscache_begin_read_operation(&rreq->cache_resources, |
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afs_vnode_cache(vnode)); |
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#else |
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return -ENOBUFS; |
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#endif |
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} |
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static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len, |
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struct folio **foliop, void **_fsdata) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
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return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0; |
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} |
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static void afs_free_request(struct netfs_io_request *rreq) |
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{ |
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key_put(rreq->netfs_priv); |
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} |
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const struct netfs_request_ops afs_req_ops = { |
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.init_request = afs_init_request, |
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.free_request = afs_free_request, |
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.begin_cache_operation = afs_begin_cache_operation, |
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.check_write_begin = afs_check_write_begin, |
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.issue_read = afs_issue_read, |
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}; |
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int afs_write_inode(struct inode *inode, struct writeback_control *wbc) |
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{ |
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fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode))); |
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return 0; |
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} |
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/* |
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* Adjust the dirty region of the page on truncation or full invalidation, |
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* getting rid of the markers altogether if the region is entirely invalidated. |
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*/ |
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static void afs_invalidate_dirty(struct folio *folio, size_t offset, |
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size_t length) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio)); |
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unsigned long priv; |
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unsigned int f, t, end = offset + length; |
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priv = (unsigned long)folio_get_private(folio); |
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/* we clean up only if the entire page is being invalidated */ |
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if (offset == 0 && length == folio_size(folio)) |
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goto full_invalidate; |
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/* If the page was dirtied by page_mkwrite(), the PTE stays writable |
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* and we don't get another notification to tell us to expand it |
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* again. |
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*/ |
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if (afs_is_folio_dirty_mmapped(priv)) |
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return; |
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/* We may need to shorten the dirty region */ |
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f = afs_folio_dirty_from(folio, priv); |
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t = afs_folio_dirty_to(folio, priv); |
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if (t <= offset || f >= end) |
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return; /* Doesn't overlap */ |
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if (f < offset && t > end) |
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return; /* Splits the dirty region - just absorb it */ |
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if (f >= offset && t <= end) |
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goto undirty; |
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if (f < offset) |
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t = offset; |
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else |
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f = end; |
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if (f == t) |
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goto undirty; |
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priv = afs_folio_dirty(folio, f, t); |
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folio_change_private(folio, (void *)priv); |
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trace_afs_folio_dirty(vnode, tracepoint_string("trunc"), folio); |
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return; |
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undirty: |
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trace_afs_folio_dirty(vnode, tracepoint_string("undirty"), folio); |
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folio_clear_dirty_for_io(folio); |
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full_invalidate: |
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trace_afs_folio_dirty(vnode, tracepoint_string("inval"), folio); |
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folio_detach_private(folio); |
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} |
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/* |
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* invalidate part or all of a page |
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* - release a page and clean up its private data if offset is 0 (indicating |
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* the entire page) |
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*/ |
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static void afs_invalidate_folio(struct folio *folio, size_t offset, |
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size_t length) |
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{ |
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_enter("{%lu},%zu,%zu", folio->index, offset, length); |
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BUG_ON(!folio_test_locked(folio)); |
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if (folio_get_private(folio)) |
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afs_invalidate_dirty(folio, offset, length); |
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folio_wait_fscache(folio); |
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_leave(""); |
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} |
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/* |
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* release a page and clean up its private state if it's not busy |
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* - return true if the page can now be released, false if not |
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*/ |
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static bool afs_release_folio(struct folio *folio, gfp_t gfp) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio)); |
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_enter("{{%llx:%llu}[%lu],%lx},%x", |
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vnode->fid.vid, vnode->fid.vnode, folio_index(folio), folio->flags, |
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gfp); |
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|
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/* deny if folio is being written to the cache and the caller hasn't |
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* elected to wait */ |
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#ifdef CONFIG_AFS_FSCACHE |
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if (folio_test_fscache(folio)) { |
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if (current_is_kswapd() || !(gfp & __GFP_FS)) |
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return false; |
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folio_wait_fscache(folio); |
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} |
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fscache_note_page_release(afs_vnode_cache(vnode)); |
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#endif |
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if (folio_test_private(folio)) { |
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trace_afs_folio_dirty(vnode, tracepoint_string("rel"), folio); |
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folio_detach_private(folio); |
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} |
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/* Indicate that the folio can be released */ |
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_leave(" = T"); |
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return true; |
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} |
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static void afs_add_open_mmap(struct afs_vnode *vnode) |
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{ |
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if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) { |
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down_write(&vnode->volume->cell->fs_open_mmaps_lock); |
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if (list_empty(&vnode->cb_mmap_link)) |
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list_add_tail(&vnode->cb_mmap_link, |
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&vnode->volume->cell->fs_open_mmaps); |
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|
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up_write(&vnode->volume->cell->fs_open_mmaps_lock); |
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} |
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} |
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static void afs_drop_open_mmap(struct afs_vnode *vnode) |
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{ |
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if (!atomic_dec_and_test(&vnode->cb_nr_mmap)) |
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return; |
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down_write(&vnode->volume->cell->fs_open_mmaps_lock); |
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|
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if (atomic_read(&vnode->cb_nr_mmap) == 0) |
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list_del_init(&vnode->cb_mmap_link); |
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up_write(&vnode->volume->cell->fs_open_mmaps_lock); |
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flush_work(&vnode->cb_work); |
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} |
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|
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/* |
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* Handle setting up a memory mapping on an AFS file. |
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*/ |
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static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) |
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{ |
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struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
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int ret; |
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|
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afs_add_open_mmap(vnode); |
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|
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ret = generic_file_mmap(file, vma); |
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if (ret == 0) |
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vma->vm_ops = &afs_vm_ops; |
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else |
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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)); |
|
struct afs_file *af = vmf->vma->vm_file->private_data; |
|
|
|
switch (afs_validate(vnode, af->key)) { |
|
case 0: |
|
return filemap_map_pages(vmf, start_pgoff, end_pgoff); |
|
case -ENOMEM: |
|
return VM_FAULT_OOM; |
|
case -EINTR: |
|
case -ERESTARTSYS: |
|
return VM_FAULT_RETRY; |
|
case -ESTALE: |
|
default: |
|
return VM_FAULT_SIGBUS; |
|
} |
|
} |
|
|
|
static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); |
|
struct afs_file *af = iocb->ki_filp->private_data; |
|
int ret; |
|
|
|
ret = afs_validate(vnode, af->key); |
|
if (ret < 0) |
|
return ret; |
|
|
|
return generic_file_read_iter(iocb, iter); |
|
}
|
|
|