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