// 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 "internal.h"
|
|
static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
|
static int afs_readpage(struct file *file, struct page *page);
|
static void afs_invalidatepage(struct page *page, unsigned int offset,
|
unsigned int length);
|
static int afs_releasepage(struct page *page, gfp_t gfp_flags);
|
|
static int afs_readpages(struct file *filp, struct address_space *mapping,
|
struct list_head *pages, unsigned nr_pages);
|
|
const struct file_operations afs_file_operations = {
|
.open = afs_open,
|
.release = afs_release,
|
.llseek = generic_file_llseek,
|
.read_iter = generic_file_read_iter,
|
.write_iter = afs_file_write,
|
.mmap = afs_file_mmap,
|
.splice_read = generic_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_fs_aops = {
|
.readpage = afs_readpage,
|
.readpages = afs_readpages,
|
.set_page_dirty = afs_set_page_dirty,
|
.launder_page = afs_launder_page,
|
.releasepage = afs_releasepage,
|
.invalidatepage = afs_invalidatepage,
|
.write_begin = afs_write_begin,
|
.write_end = afs_write_end,
|
.writepage = afs_writepage,
|
.writepages = afs_writepages,
|
};
|
|
static const struct vm_operations_struct afs_vm_ops = {
|
.fault = filemap_fault,
|
.map_pages = filemap_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);
|
|
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 *vnode = AFS_FS_I(inode);
|
struct afs_file *af = file->private_data;
|
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);
|
key_put(af->key);
|
kfree(af);
|
afs_prune_wb_keys(vnode);
|
_leave(" = %d", ret);
|
return ret;
|
}
|
|
/*
|
* Dispose of a ref to a read record.
|
*/
|
void afs_put_read(struct afs_read *req)
|
{
|
int i;
|
|
if (refcount_dec_and_test(&req->usage)) {
|
if (req->pages) {
|
for (i = 0; i < req->nr_pages; i++)
|
if (req->pages[i])
|
put_page(req->pages[i]);
|
if (req->pages != req->array)
|
kfree(req->pages);
|
}
|
kfree(req);
|
}
|
}
|
|
#ifdef CONFIG_AFS_FSCACHE
|
/*
|
* deal with notification that a page was read from the cache
|
*/
|
static void afs_file_readpage_read_complete(struct page *page,
|
void *data,
|
int error)
|
{
|
_enter("%p,%p,%d", page, data, error);
|
|
/* if the read completes with an error, we just unlock the page and let
|
* the VM reissue the readpage */
|
if (!error)
|
SetPageUptodate(page);
|
unlock_page(page);
|
}
|
#endif
|
|
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);
|
}
|
|
static void afs_fetch_data_put(struct afs_operation *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,
|
.put = afs_fetch_data_put,
|
};
|
|
/*
|
* Fetch file data from the volume.
|
*/
|
int afs_fetch_data(struct afs_vnode *vnode, struct key *key, 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(key));
|
|
op = afs_alloc_operation(key, vnode->volume);
|
if (IS_ERR(op))
|
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);
|
}
|
|
/*
|
* read page from file, directory or symlink, given a key to use
|
*/
|
int afs_page_filler(void *data, struct page *page)
|
{
|
struct inode *inode = page->mapping->host;
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
struct afs_read *req;
|
struct key *key = data;
|
int ret;
|
|
_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
|
|
BUG_ON(!PageLocked(page));
|
|
ret = -ESTALE;
|
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
|
goto error;
|
|
/* is it cached? */
|
#ifdef CONFIG_AFS_FSCACHE
|
ret = fscache_read_or_alloc_page(vnode->cache,
|
page,
|
afs_file_readpage_read_complete,
|
NULL,
|
GFP_KERNEL);
|
#else
|
ret = -ENOBUFS;
|
#endif
|
switch (ret) {
|
/* read BIO submitted (page in cache) */
|
case 0:
|
break;
|
|
/* page not yet cached */
|
case -ENODATA:
|
_debug("cache said ENODATA");
|
goto go_on;
|
|
/* page will not be cached */
|
case -ENOBUFS:
|
_debug("cache said ENOBUFS");
|
|
fallthrough;
|
default:
|
go_on:
|
req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
|
if (!req)
|
goto enomem;
|
|
/* We request a full page. If the page is a partial one at the
|
* end of the file, the server will return a short read and the
|
* unmarshalling code will clear the unfilled space.
|
*/
|
refcount_set(&req->usage, 1);
|
req->pos = (loff_t)page->index << PAGE_SHIFT;
|
req->len = PAGE_SIZE;
|
req->nr_pages = 1;
|
req->pages = req->array;
|
req->pages[0] = page;
|
get_page(page);
|
|
/* read the contents of the file from the server into the
|
* page */
|
ret = afs_fetch_data(vnode, key, req);
|
afs_put_read(req);
|
|
if (ret < 0) {
|
if (ret == -ENOENT) {
|
_debug("got NOENT from server"
|
" - marking file deleted and stale");
|
set_bit(AFS_VNODE_DELETED, &vnode->flags);
|
ret = -ESTALE;
|
}
|
|
#ifdef CONFIG_AFS_FSCACHE
|
fscache_uncache_page(vnode->cache, page);
|
#endif
|
BUG_ON(PageFsCache(page));
|
|
if (ret == -EINTR ||
|
ret == -ENOMEM ||
|
ret == -ERESTARTSYS ||
|
ret == -EAGAIN)
|
goto error;
|
goto io_error;
|
}
|
|
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);
|
}
|
|
_leave(" = 0");
|
return 0;
|
|
io_error:
|
SetPageError(page);
|
goto error;
|
enomem:
|
ret = -ENOMEM;
|
error:
|
unlock_page(page);
|
_leave(" = %d", ret);
|
return ret;
|
}
|
|
/*
|
* read page from file, directory or symlink, given a file to nominate the key
|
* to be used
|
*/
|
static int afs_readpage(struct file *file, struct page *page)
|
{
|
struct key *key;
|
int ret;
|
|
if (file) {
|
key = afs_file_key(file);
|
ASSERT(key != NULL);
|
ret = afs_page_filler(key, page);
|
} else {
|
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 {
|
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.
|
*/
|
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) {
|
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;
|
}
|
