linux/fs/9p/vfs_file.c
Thomas Gleixner 1f32761322 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to free software
  foundation 51 franklin street fifth floor boston ma 02111 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 27 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:21 -07:00

712 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/9p/vfs_file.c
*
* This file contians vfs file ops for 9P2000.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/utsname.h>
#include <linux/uaccess.h>
#include <linux/idr.h>
#include <linux/uio.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
#include "cache.h"
static const struct vm_operations_struct v9fs_file_vm_ops;
static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
/**
* v9fs_file_open - open a file (or directory)
* @inode: inode to be opened
* @file: file being opened
*
*/
int v9fs_file_open(struct inode *inode, struct file *file)
{
int err;
struct v9fs_inode *v9inode;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
int omode;
p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
v9inode = V9FS_I(inode);
v9ses = v9fs_inode2v9ses(inode);
if (v9fs_proto_dotl(v9ses))
omode = v9fs_open_to_dotl_flags(file->f_flags);
else
omode = v9fs_uflags2omode(file->f_flags,
v9fs_proto_dotu(v9ses));
fid = file->private_data;
if (!fid) {
fid = v9fs_fid_clone(file_dentry(file));
if (IS_ERR(fid))
return PTR_ERR(fid);
err = p9_client_open(fid, omode);
if (err < 0) {
p9_client_clunk(fid);
return err;
}
if ((file->f_flags & O_APPEND) &&
(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
generic_file_llseek(file, 0, SEEK_END);
}
file->private_data = fid;
mutex_lock(&v9inode->v_mutex);
if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
!v9inode->writeback_fid &&
((file->f_flags & O_ACCMODE) != O_RDONLY)) {
/*
* clone a fid and add it to writeback_fid
* we do it during open time instead of
* page dirty time via write_begin/page_mkwrite
* because we want write after unlink usecase
* to work.
*/
fid = v9fs_writeback_fid(file_dentry(file));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
mutex_unlock(&v9inode->v_mutex);
goto out_error;
}
v9inode->writeback_fid = (void *) fid;
}
mutex_unlock(&v9inode->v_mutex);
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
v9fs_cache_inode_set_cookie(inode, file);
return 0;
out_error:
p9_client_clunk(file->private_data);
file->private_data = NULL;
return err;
}
/**
* v9fs_file_lock - lock a file (or directory)
* @filp: file to be locked
* @cmd: lock command
* @fl: file lock structure
*
* Bugs: this looks like a local only lock, we should extend into 9P
* by using open exclusive
*/
static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
{
int res = 0;
struct inode *inode = file_inode(filp);
p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
/* No mandatory locks */
if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
return -ENOLCK;
if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
filemap_write_and_wait(inode->i_mapping);
invalidate_mapping_pages(&inode->i_data, 0, -1);
}
return res;
}
static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
{
struct p9_flock flock;
struct p9_fid *fid;
uint8_t status = P9_LOCK_ERROR;
int res = 0;
unsigned char fl_type;
struct v9fs_session_info *v9ses;
fid = filp->private_data;
BUG_ON(fid == NULL);
if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
BUG();
res = locks_lock_file_wait(filp, fl);
if (res < 0)
goto out;
/* convert posix lock to p9 tlock args */
memset(&flock, 0, sizeof(flock));
/* map the lock type */
switch (fl->fl_type) {
case F_RDLCK:
flock.type = P9_LOCK_TYPE_RDLCK;
break;
case F_WRLCK:
flock.type = P9_LOCK_TYPE_WRLCK;
break;
case F_UNLCK:
flock.type = P9_LOCK_TYPE_UNLCK;
break;
}
flock.start = fl->fl_start;
if (fl->fl_end == OFFSET_MAX)
flock.length = 0;
else
flock.length = fl->fl_end - fl->fl_start + 1;
flock.proc_id = fl->fl_pid;
flock.client_id = fid->clnt->name;
if (IS_SETLKW(cmd))
flock.flags = P9_LOCK_FLAGS_BLOCK;
v9ses = v9fs_inode2v9ses(file_inode(filp));
/*
* if its a blocked request and we get P9_LOCK_BLOCKED as the status
* for lock request, keep on trying
*/
for (;;) {
res = p9_client_lock_dotl(fid, &flock, &status);
if (res < 0)
goto out_unlock;
if (status != P9_LOCK_BLOCKED)
break;
if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
break;
if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
!= 0)
break;
/*
* p9_client_lock_dotl overwrites flock.client_id with the
* server message, free and reuse the client name
*/
if (flock.client_id != fid->clnt->name) {
kfree(flock.client_id);
flock.client_id = fid->clnt->name;
}
}
/* map 9p status to VFS status */
switch (status) {
case P9_LOCK_SUCCESS:
res = 0;
break;
case P9_LOCK_BLOCKED:
res = -EAGAIN;
break;
default:
WARN_ONCE(1, "unknown lock status code: %d\n", status);
/* fall through */
case P9_LOCK_ERROR:
case P9_LOCK_GRACE:
res = -ENOLCK;
break;
}
out_unlock:
/*
* incase server returned error for lock request, revert
* it locally
*/
if (res < 0 && fl->fl_type != F_UNLCK) {
fl_type = fl->fl_type;
fl->fl_type = F_UNLCK;
/* Even if this fails we want to return the remote error */
locks_lock_file_wait(filp, fl);
fl->fl_type = fl_type;
}
if (flock.client_id != fid->clnt->name)
kfree(flock.client_id);
out:
return res;
}
static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
{
struct p9_getlock glock;
struct p9_fid *fid;
int res = 0;
fid = filp->private_data;
BUG_ON(fid == NULL);
posix_test_lock(filp, fl);
/*
* if we have a conflicting lock locally, no need to validate
* with server
*/
if (fl->fl_type != F_UNLCK)
return res;
/* convert posix lock to p9 tgetlock args */
memset(&glock, 0, sizeof(glock));
glock.type = P9_LOCK_TYPE_UNLCK;
glock.start = fl->fl_start;
if (fl->fl_end == OFFSET_MAX)
glock.length = 0;
else
glock.length = fl->fl_end - fl->fl_start + 1;
glock.proc_id = fl->fl_pid;
glock.client_id = fid->clnt->name;
res = p9_client_getlock_dotl(fid, &glock);
if (res < 0)
goto out;
/* map 9p lock type to os lock type */
switch (glock.type) {
case P9_LOCK_TYPE_RDLCK:
fl->fl_type = F_RDLCK;
break;
case P9_LOCK_TYPE_WRLCK:
fl->fl_type = F_WRLCK;
break;
case P9_LOCK_TYPE_UNLCK:
fl->fl_type = F_UNLCK;
break;
}
if (glock.type != P9_LOCK_TYPE_UNLCK) {
fl->fl_start = glock.start;
if (glock.length == 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = glock.start + glock.length - 1;
fl->fl_pid = -glock.proc_id;
}
out:
if (glock.client_id != fid->clnt->name)
kfree(glock.client_id);
return res;
}
/**
* v9fs_file_lock_dotl - lock a file (or directory)
* @filp: file to be locked
* @cmd: lock command
* @fl: file lock structure
*
*/
static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl)
{
struct inode *inode = file_inode(filp);
int ret = -ENOLCK;
p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
filp, cmd, fl, filp);
/* No mandatory locks */
if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
goto out_err;
if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
filemap_write_and_wait(inode->i_mapping);
invalidate_mapping_pages(&inode->i_data, 0, -1);
}
if (IS_SETLK(cmd) || IS_SETLKW(cmd))
ret = v9fs_file_do_lock(filp, cmd, fl);
else if (IS_GETLK(cmd))
ret = v9fs_file_getlock(filp, fl);
else
ret = -EINVAL;
out_err:
return ret;
}
/**
* v9fs_file_flock_dotl - lock a file
* @filp: file to be locked
* @cmd: lock command
* @fl: file lock structure
*
*/
static int v9fs_file_flock_dotl(struct file *filp, int cmd,
struct file_lock *fl)
{
struct inode *inode = file_inode(filp);
int ret = -ENOLCK;
p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
filp, cmd, fl, filp);
/* No mandatory locks */
if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
goto out_err;
if (!(fl->fl_flags & FL_FLOCK))
goto out_err;
if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
filemap_write_and_wait(inode->i_mapping);
invalidate_mapping_pages(&inode->i_data, 0, -1);
}
/* Convert flock to posix lock */
fl->fl_flags |= FL_POSIX;
fl->fl_flags ^= FL_FLOCK;
if (IS_SETLK(cmd) | IS_SETLKW(cmd))
ret = v9fs_file_do_lock(filp, cmd, fl);
else
ret = -EINVAL;
out_err:
return ret;
}
/**
* v9fs_file_read - read from a file
* @filp: file pointer to read
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
static ssize_t
v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct p9_fid *fid = iocb->ki_filp->private_data;
int ret, err = 0;
p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
iov_iter_count(to), iocb->ki_pos);
ret = p9_client_read(fid, iocb->ki_pos, to, &err);
if (!ret)
return err;
iocb->ki_pos += ret;
return ret;
}
/**
* v9fs_file_write - write to a file
* @filp: file pointer to write
* @data: data buffer to write data from
* @count: size of buffer
* @offset: offset at which to write data
*
*/
static ssize_t
v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
ssize_t retval;
loff_t origin;
int err = 0;
retval = generic_write_checks(iocb, from);
if (retval <= 0)
return retval;
origin = iocb->ki_pos;
retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
if (retval > 0) {
struct inode *inode = file_inode(file);
loff_t i_size;
unsigned long pg_start, pg_end;
pg_start = origin >> PAGE_SHIFT;
pg_end = (origin + retval - 1) >> PAGE_SHIFT;
if (inode->i_mapping && inode->i_mapping->nrpages)
invalidate_inode_pages2_range(inode->i_mapping,
pg_start, pg_end);
iocb->ki_pos += retval;
i_size = i_size_read(inode);
if (iocb->ki_pos > i_size) {
inode_add_bytes(inode, iocb->ki_pos - i_size);
/*
* Need to serialize against i_size_write() in
* v9fs_stat2inode()
*/
v9fs_i_size_write(inode, iocb->ki_pos);
}
return retval;
}
return err;
}
static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
int datasync)
{
struct p9_fid *fid;
struct inode *inode = filp->f_mapping->host;
struct p9_wstat wstat;
int retval;
retval = file_write_and_wait_range(filp, start, end);
if (retval)
return retval;
inode_lock(inode);
p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
fid = filp->private_data;
v9fs_blank_wstat(&wstat);
retval = p9_client_wstat(fid, &wstat);
inode_unlock(inode);
return retval;
}
int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
int datasync)
{
struct p9_fid *fid;
struct inode *inode = filp->f_mapping->host;
int retval;
retval = file_write_and_wait_range(filp, start, end);
if (retval)
return retval;
inode_lock(inode);
p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
fid = filp->private_data;
retval = p9_client_fsync(fid, datasync);
inode_unlock(inode);
return retval;
}
static int
v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
{
int retval;
retval = generic_file_mmap(filp, vma);
if (!retval)
vma->vm_ops = &v9fs_file_vm_ops;
return retval;
}
static int
v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
{
int retval;
struct inode *inode;
struct v9fs_inode *v9inode;
struct p9_fid *fid;
inode = file_inode(filp);
v9inode = V9FS_I(inode);
mutex_lock(&v9inode->v_mutex);
if (!v9inode->writeback_fid &&
(vma->vm_flags & VM_WRITE)) {
/*
* clone a fid and add it to writeback_fid
* we do it during mmap instead of
* page dirty time via write_begin/page_mkwrite
* because we want write after unlink usecase
* to work.
*/
fid = v9fs_writeback_fid(file_dentry(filp));
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
mutex_unlock(&v9inode->v_mutex);
return retval;
}
v9inode->writeback_fid = (void *) fid;
}
mutex_unlock(&v9inode->v_mutex);
retval = generic_file_mmap(filp, vma);
if (!retval)
vma->vm_ops = &v9fs_mmap_file_vm_ops;
return retval;
}
static vm_fault_t
v9fs_vm_page_mkwrite(struct vm_fault *vmf)
{
struct v9fs_inode *v9inode;
struct page *page = vmf->page;
struct file *filp = vmf->vma->vm_file;
struct inode *inode = file_inode(filp);
p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
page, (unsigned long)filp->private_data);
/* Update file times before taking page lock */
file_update_time(filp);
v9inode = V9FS_I(inode);
/* make sure the cache has finished storing the page */
v9fs_fscache_wait_on_page_write(inode, page);
BUG_ON(!v9inode->writeback_fid);
lock_page(page);
if (page->mapping != inode->i_mapping)
goto out_unlock;
wait_for_stable_page(page);
return VM_FAULT_LOCKED;
out_unlock:
unlock_page(page);
return VM_FAULT_NOPAGE;
}
/**
* v9fs_mmap_file_read - read from a file
* @filp: file pointer to read
* @data: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
static ssize_t
v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
/* TODO: Check if there are dirty pages */
return v9fs_file_read_iter(iocb, to);
}
/**
* v9fs_mmap_file_write - write to a file
* @filp: file pointer to write
* @data: data buffer to write data from
* @count: size of buffer
* @offset: offset at which to write data
*
*/
static ssize_t
v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
/*
* TODO: invalidate mmaps on filp's inode between
* offset and offset+count
*/
return v9fs_file_write_iter(iocb, from);
}
static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
{
struct inode *inode;
struct writeback_control wbc = {
.nr_to_write = LONG_MAX,
.sync_mode = WB_SYNC_ALL,
.range_start = vma->vm_pgoff * PAGE_SIZE,
/* absolute end, byte at end included */
.range_end = vma->vm_pgoff * PAGE_SIZE +
(vma->vm_end - vma->vm_start - 1),
};
p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
inode = file_inode(vma->vm_file);
if (!mapping_cap_writeback_dirty(inode->i_mapping))
wbc.nr_to_write = 0;
might_sleep();
sync_inode(inode, &wbc);
}
static const struct vm_operations_struct v9fs_file_vm_ops = {
.fault = filemap_fault,
.map_pages = filemap_map_pages,
.page_mkwrite = v9fs_vm_page_mkwrite,
};
static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
.close = v9fs_mmap_vm_close,
.fault = filemap_fault,
.map_pages = filemap_map_pages,
.page_mkwrite = v9fs_vm_page_mkwrite,
};
const struct file_operations v9fs_cached_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = v9fs_file_mmap,
.fsync = v9fs_file_fsync,
};
const struct file_operations v9fs_cached_file_operations_dotl = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock_dotl,
.flock = v9fs_file_flock_dotl,
.mmap = v9fs_file_mmap,
.fsync = v9fs_file_fsync_dotl,
};
const struct file_operations v9fs_file_operations = {
.llseek = generic_file_llseek,
.read_iter = v9fs_file_read_iter,
.write_iter = v9fs_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = generic_file_readonly_mmap,
.fsync = v9fs_file_fsync,
};
const struct file_operations v9fs_file_operations_dotl = {
.llseek = generic_file_llseek,
.read_iter = v9fs_file_read_iter,
.write_iter = v9fs_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock_dotl,
.flock = v9fs_file_flock_dotl,
.mmap = generic_file_readonly_mmap,
.fsync = v9fs_file_fsync_dotl,
};
const struct file_operations v9fs_mmap_file_operations = {
.llseek = generic_file_llseek,
.read_iter = v9fs_mmap_file_read_iter,
.write_iter = v9fs_mmap_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = v9fs_mmap_file_mmap,
.fsync = v9fs_file_fsync,
};
const struct file_operations v9fs_mmap_file_operations_dotl = {
.llseek = generic_file_llseek,
.read_iter = v9fs_mmap_file_read_iter,
.write_iter = v9fs_mmap_file_write_iter,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock_dotl,
.flock = v9fs_file_flock_dotl,
.mmap = v9fs_mmap_file_mmap,
.fsync = v9fs_file_fsync_dotl,
};