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733 lines
16 KiB
733 lines
16 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* AFS filesystem file handling |
|
* |
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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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#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 "internal.h" |
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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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static int afs_readpage(struct file *file, struct page *page); |
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static void afs_invalidatepage(struct page *page, unsigned int offset, |
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unsigned int length); |
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static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
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|
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static int afs_readpages(struct file *filp, struct address_space *mapping, |
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struct list_head *pages, unsigned nr_pages); |
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|
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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 = generic_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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|
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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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|
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const struct address_space_operations afs_fs_aops = { |
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.readpage = afs_readpage, |
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.readpages = afs_readpages, |
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.set_page_dirty = afs_set_page_dirty, |
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.launder_page = afs_launder_page, |
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.releasepage = afs_releasepage, |
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.invalidatepage = afs_invalidatepage, |
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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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|
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static const struct vm_operations_struct afs_vm_ops = { |
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.fault = filemap_fault, |
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.map_pages = filemap_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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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file->private_data = af; |
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_leave(" = 0"); |
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return 0; |
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|
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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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/* |
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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 *vnode = AFS_FS_I(inode); |
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struct afs_file *af = file->private_data; |
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int ret = 0; |
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|
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_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
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|
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if ((file->f_mode & FMODE_WRITE)) |
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ret = vfs_fsync(file, 0); |
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|
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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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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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* 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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int i; |
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|
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if (refcount_dec_and_test(&req->usage)) { |
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if (req->pages) { |
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for (i = 0; i < req->nr_pages; i++) |
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if (req->pages[i]) |
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put_page(req->pages[i]); |
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if (req->pages != req->array) |
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kfree(req->pages); |
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} |
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kfree(req); |
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} |
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} |
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|
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#ifdef CONFIG_AFS_FSCACHE |
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/* |
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* deal with notification that a page was read from the cache |
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*/ |
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static void afs_file_readpage_read_complete(struct page *page, |
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void *data, |
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int error) |
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{ |
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_enter("%p,%p,%d", page, data, error); |
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|
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/* if the read completes with an error, we just unlock the page and let |
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* the VM reissue the readpage */ |
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if (!error) |
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SetPageUptodate(page); |
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unlock_page(page); |
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} |
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#endif |
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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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|
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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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} |
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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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afs_put_read(op->fetch.req); |
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} |
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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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.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 key *key, struct afs_read *req) |
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{ |
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struct afs_operation *op; |
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|
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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(key)); |
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|
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op = afs_alloc_operation(key, vnode->volume); |
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if (IS_ERR(op)) |
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return PTR_ERR(op); |
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afs_op_set_vnode(op, 0, vnode); |
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|
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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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|
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/* |
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* read page from file, directory or symlink, given a key to use |
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*/ |
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int afs_page_filler(void *data, struct page *page) |
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{ |
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struct inode *inode = page->mapping->host; |
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struct afs_vnode *vnode = AFS_FS_I(inode); |
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struct afs_read *req; |
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struct key *key = data; |
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int ret; |
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|
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_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); |
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|
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BUG_ON(!PageLocked(page)); |
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|
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ret = -ESTALE; |
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if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
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goto error; |
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|
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/* is it cached? */ |
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#ifdef CONFIG_AFS_FSCACHE |
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ret = fscache_read_or_alloc_page(vnode->cache, |
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page, |
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afs_file_readpage_read_complete, |
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NULL, |
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GFP_KERNEL); |
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#else |
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ret = -ENOBUFS; |
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#endif |
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switch (ret) { |
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/* read BIO submitted (page in cache) */ |
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case 0: |
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break; |
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|
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/* page not yet cached */ |
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case -ENODATA: |
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_debug("cache said ENODATA"); |
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goto go_on; |
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|
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/* page will not be cached */ |
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case -ENOBUFS: |
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_debug("cache said ENOBUFS"); |
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|
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fallthrough; |
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default: |
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go_on: |
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req = kzalloc(struct_size(req, array, 1), GFP_KERNEL); |
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if (!req) |
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goto enomem; |
|
|
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/* We request a full page. If the page is a partial one at the |
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* end of the file, the server will return a short read and the |
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* unmarshalling code will clear the unfilled space. |
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*/ |
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refcount_set(&req->usage, 1); |
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req->pos = (loff_t)page->index << PAGE_SHIFT; |
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req->len = PAGE_SIZE; |
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req->nr_pages = 1; |
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req->pages = req->array; |
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req->pages[0] = page; |
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get_page(page); |
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|
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/* read the contents of the file from the server into the |
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* page */ |
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ret = afs_fetch_data(vnode, key, req); |
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afs_put_read(req); |
|
|
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if (ret < 0) { |
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if (ret == -ENOENT) { |
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_debug("got NOENT from server" |
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" - marking file deleted and stale"); |
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set_bit(AFS_VNODE_DELETED, &vnode->flags); |
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ret = -ESTALE; |
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} |
|
|
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#ifdef CONFIG_AFS_FSCACHE |
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fscache_uncache_page(vnode->cache, page); |
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#endif |
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BUG_ON(PageFsCache(page)); |
|
|
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if (ret == -EINTR || |
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ret == -ENOMEM || |
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ret == -ERESTARTSYS || |
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ret == -EAGAIN) |
|
goto error; |
|
goto io_error; |
|
} |
|
|
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SetPageUptodate(page); |
|
|
|
/* send the page to the cache */ |
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#ifdef CONFIG_AFS_FSCACHE |
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if (PageFsCache(page) && |
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fscache_write_page(vnode->cache, page, vnode->status.size, |
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GFP_KERNEL) != 0) { |
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fscache_uncache_page(vnode->cache, page); |
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BUG_ON(PageFsCache(page)); |
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} |
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#endif |
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unlock_page(page); |
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} |
|
|
|
_leave(" = 0"); |
|
return 0; |
|
|
|
io_error: |
|
SetPageError(page); |
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goto error; |
|
enomem: |
|
ret = -ENOMEM; |
|
error: |
|
unlock_page(page); |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
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* read page from file, directory or symlink, given a file to nominate the key |
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* to be used |
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*/ |
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static int afs_readpage(struct file *file, struct page *page) |
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{ |
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struct key *key; |
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int ret; |
|
|
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if (file) { |
|
key = afs_file_key(file); |
|
ASSERT(key != NULL); |
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ret = afs_page_filler(key, page); |
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} else { |
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struct inode *inode = page->mapping->host; |
|
key = afs_request_key(AFS_FS_S(inode->i_sb)->cell); |
|
if (IS_ERR(key)) { |
|
ret = PTR_ERR(key); |
|
} else { |
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ret = afs_page_filler(key, page); |
|
key_put(key); |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* Make pages available as they're filled. |
|
*/ |
|
static void afs_readpages_page_done(struct afs_read *req) |
|
{ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
struct afs_vnode *vnode = req->vnode; |
|
#endif |
|
struct page *page = req->pages[req->index]; |
|
|
|
req->pages[req->index] = NULL; |
|
SetPageUptodate(page); |
|
|
|
/* send the page to the cache */ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
if (PageFsCache(page) && |
|
fscache_write_page(vnode->cache, page, vnode->status.size, |
|
GFP_KERNEL) != 0) { |
|
fscache_uncache_page(vnode->cache, page); |
|
BUG_ON(PageFsCache(page)); |
|
} |
|
#endif |
|
unlock_page(page); |
|
put_page(page); |
|
} |
|
|
|
/* |
|
* Read a contiguous set of pages. |
|
*/ |
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static int afs_readpages_one(struct file *file, struct address_space *mapping, |
|
struct list_head *pages) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
struct afs_read *req; |
|
struct list_head *p; |
|
struct page *first, *page; |
|
struct key *key = afs_file_key(file); |
|
pgoff_t index; |
|
int ret, n, i; |
|
|
|
/* Count the number of contiguous pages at the front of the list. Note |
|
* that the list goes prev-wards rather than next-wards. |
|
*/ |
|
first = lru_to_page(pages); |
|
index = first->index + 1; |
|
n = 1; |
|
for (p = first->lru.prev; p != pages; p = p->prev) { |
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page = list_entry(p, struct page, lru); |
|
if (page->index != index) |
|
break; |
|
index++; |
|
n++; |
|
} |
|
|
|
req = kzalloc(struct_size(req, array, n), GFP_NOFS); |
|
if (!req) |
|
return -ENOMEM; |
|
|
|
refcount_set(&req->usage, 1); |
|
req->vnode = vnode; |
|
req->page_done = afs_readpages_page_done; |
|
req->pos = first->index; |
|
req->pos <<= PAGE_SHIFT; |
|
req->pages = req->array; |
|
|
|
/* Transfer the pages to the request. We add them in until one fails |
|
* to add to the LRU and then we stop (as that'll make a hole in the |
|
* contiguous run. |
|
* |
|
* Note that it's possible for the file size to change whilst we're |
|
* doing this, but we rely on the server returning less than we asked |
|
* for if the file shrank. We also rely on this to deal with a partial |
|
* page at the end of the file. |
|
*/ |
|
do { |
|
page = lru_to_page(pages); |
|
list_del(&page->lru); |
|
index = page->index; |
|
if (add_to_page_cache_lru(page, mapping, index, |
|
readahead_gfp_mask(mapping))) { |
|
#ifdef CONFIG_AFS_FSCACHE |
|
fscache_uncache_page(vnode->cache, page); |
|
#endif |
|
put_page(page); |
|
break; |
|
} |
|
|
|
req->pages[req->nr_pages++] = page; |
|
req->len += PAGE_SIZE; |
|
} while (req->nr_pages < n); |
|
|
|
if (req->nr_pages == 0) { |
|
kfree(req); |
|
return 0; |
|
} |
|
|
|
ret = afs_fetch_data(vnode, key, req); |
|
if (ret < 0) |
|
goto error; |
|
|
|
task_io_account_read(PAGE_SIZE * req->nr_pages); |
|
afs_put_read(req); |
|
return 0; |
|
|
|
error: |
|
if (ret == -ENOENT) { |
|
_debug("got NOENT from server" |
|
" - marking file deleted and stale"); |
|
set_bit(AFS_VNODE_DELETED, &vnode->flags); |
|
ret = -ESTALE; |
|
} |
|
|
|
for (i = 0; i < req->nr_pages; i++) { |
|
page = req->pages[i]; |
|
if (page) { |
|
#ifdef CONFIG_AFS_FSCACHE |
|
fscache_uncache_page(vnode->cache, page); |
|
#endif |
|
SetPageError(page); |
|
unlock_page(page); |
|
} |
|
} |
|
|
|
afs_put_read(req); |
|
return ret; |
|
} |
|
|
|
/* |
|
* read a set of pages |
|
*/ |
|
static int afs_readpages(struct file *file, struct address_space *mapping, |
|
struct list_head *pages, unsigned nr_pages) |
|
{ |
|
struct key *key = afs_file_key(file); |
|
struct afs_vnode *vnode; |
|
int ret = 0; |
|
|
|
_enter("{%d},{%lu},,%d", |
|
key_serial(key), mapping->host->i_ino, nr_pages); |
|
|
|
ASSERT(key != NULL); |
|
|
|
vnode = AFS_FS_I(mapping->host); |
|
if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
|
_leave(" = -ESTALE"); |
|
return -ESTALE; |
|
} |
|
|
|
/* attempt to read as many of the pages as possible */ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
ret = fscache_read_or_alloc_pages(vnode->cache, |
|
mapping, |
|
pages, |
|
&nr_pages, |
|
afs_file_readpage_read_complete, |
|
NULL, |
|
mapping_gfp_mask(mapping)); |
|
#else |
|
ret = -ENOBUFS; |
|
#endif |
|
|
|
switch (ret) { |
|
/* all pages are being read from the cache */ |
|
case 0: |
|
BUG_ON(!list_empty(pages)); |
|
BUG_ON(nr_pages != 0); |
|
_leave(" = 0 [reading all]"); |
|
return 0; |
|
|
|
/* there were pages that couldn't be read from the cache */ |
|
case -ENODATA: |
|
case -ENOBUFS: |
|
break; |
|
|
|
/* other error */ |
|
default: |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
while (!list_empty(pages)) { |
|
ret = afs_readpages_one(file, mapping, pages); |
|
if (ret < 0) |
|
break; |
|
} |
|
|
|
_leave(" = %d [netting]", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Adjust the dirty region of the page on truncation or full invalidation, |
|
* getting rid of the markers altogether if the region is entirely invalidated. |
|
*/ |
|
static void afs_invalidate_dirty(struct page *page, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
unsigned long priv; |
|
unsigned int f, t, end = offset + length; |
|
|
|
priv = page_private(page); |
|
|
|
/* we clean up only if the entire page is being invalidated */ |
|
if (offset == 0 && length == thp_size(page)) |
|
goto full_invalidate; |
|
|
|
/* If the page was dirtied by page_mkwrite(), the PTE stays writable |
|
* and we don't get another notification to tell us to expand it |
|
* again. |
|
*/ |
|
if (afs_is_page_dirty_mmapped(priv)) |
|
return; |
|
|
|
/* We may need to shorten the dirty region */ |
|
f = afs_page_dirty_from(priv); |
|
t = afs_page_dirty_to(priv); |
|
|
|
if (t <= offset || f >= end) |
|
return; /* Doesn't overlap */ |
|
|
|
if (f < offset && t > end) |
|
return; /* Splits the dirty region - just absorb it */ |
|
|
|
if (f >= offset && t <= end) |
|
goto undirty; |
|
|
|
if (f < offset) |
|
t = offset; |
|
else |
|
f = end; |
|
if (f == t) |
|
goto undirty; |
|
|
|
priv = afs_page_dirty(f, t); |
|
set_page_private(page, priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("trunc"), page->index, priv); |
|
return; |
|
|
|
undirty: |
|
trace_afs_page_dirty(vnode, tracepoint_string("undirty"), page->index, priv); |
|
clear_page_dirty_for_io(page); |
|
full_invalidate: |
|
priv = (unsigned long)detach_page_private(page); |
|
trace_afs_page_dirty(vnode, tracepoint_string("inval"), page->index, priv); |
|
} |
|
|
|
/* |
|
* invalidate part or all of a page |
|
* - release a page and clean up its private data if offset is 0 (indicating |
|
* the entire page) |
|
*/ |
|
static void afs_invalidatepage(struct page *page, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
_enter("{%lu},%u,%u", page->index, offset, length); |
|
|
|
BUG_ON(!PageLocked(page)); |
|
|
|
#ifdef CONFIG_AFS_FSCACHE |
|
/* we clean up only if the entire page is being invalidated */ |
|
if (offset == 0 && length == PAGE_SIZE) { |
|
if (PageFsCache(page)) { |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
fscache_wait_on_page_write(vnode->cache, page); |
|
fscache_uncache_page(vnode->cache, page); |
|
} |
|
} |
|
#endif |
|
|
|
if (PagePrivate(page)) |
|
afs_invalidate_dirty(page, offset, length); |
|
|
|
_leave(""); |
|
} |
|
|
|
/* |
|
* release a page and clean up its private state if it's not busy |
|
* - return true if the page can now be released, false if not |
|
*/ |
|
static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
unsigned long priv; |
|
|
|
_enter("{{%llx:%llu}[%lu],%lx},%x", |
|
vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, |
|
gfp_flags); |
|
|
|
/* deny if page is being written to the cache and the caller hasn't |
|
* elected to wait */ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) { |
|
_leave(" = F [cache busy]"); |
|
return 0; |
|
} |
|
#endif |
|
|
|
if (PagePrivate(page)) { |
|
priv = (unsigned long)detach_page_private(page); |
|
trace_afs_page_dirty(vnode, tracepoint_string("rel"), |
|
page->index, priv); |
|
} |
|
|
|
/* indicate that the page can be released */ |
|
_leave(" = T"); |
|
return 1; |
|
} |
|
|
|
/* |
|
* Handle setting up a memory mapping on an AFS file. |
|
*/ |
|
static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
|
int ret; |
|
|
|
ret = generic_file_mmap(file, vma); |
|
if (ret == 0) |
|
vma->vm_ops = &afs_vm_ops; |
|
return ret; |
|
}
|
|
|