[linux-2.6-block.git] / fs / 9p / vfs_file.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/filelock.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/utsname.h>
#include <linux/uaccess.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_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_session_info *v9ses;
	struct p9_fid *fid;
	int omode;

	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
	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);

		if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) {
			int writeback_omode = (omode & ~P9_OWRITE) | P9_ORDWR;

			p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n");
			err = p9_client_open(fid, writeback_omode);
			if (err < 0) {
				p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n");
				err = p9_client_open(fid, omode);
				fid->mode |= P9L_DIRECT;
			}
		} else {
			err = p9_client_open(fid, omode);
		}
		if (err < 0) {
			p9_fid_put(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;
	}

#ifdef CONFIG_9P_FSCACHE
	if (v9ses->cache & CACHE_FSCACHE)
		fscache_use_cookie(v9fs_inode_cookie(V9FS_I(inode)),
				   file->f_mode & FMODE_WRITE);
#endif
	v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
	v9fs_open_fid_add(inode, &fid);
	return 0;
}

/**
 * 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)
{
	struct inode *inode = file_inode(filp);

	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

	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 0;
}

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);

	BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);

	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);
		fallthrough;
	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);

	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;
	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);

	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_iter - read from a file
 * @iocb: The operation parameters
 * @to: The buffer to read into
 *
 */
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, "fid %d count %zu offset %lld\n",
		 fid->fid, iov_iter_count(to), iocb->ki_pos);

	if (!(fid->mode & P9L_DIRECT)) {
		p9_debug(P9_DEBUG_VFS, "(cached)\n");
		return generic_file_read_iter(iocb, to);
	}

	if (iocb->ki_filp->f_flags & O_NONBLOCK)
		ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
	else
		ret = p9_client_read(fid, iocb->ki_pos, to, &err);
	if (!ret)
		return err;

	iocb->ki_pos += ret;
	return ret;
}

/*
 * v9fs_file_splice_read - splice-read from a file
 * @in: The 9p file to read from
 * @ppos: Where to find/update the file position
 * @pipe: The pipe to splice into
 * @len: The maximum amount of data to splice
 * @flags: SPLICE_F_* flags
 */
static ssize_t v9fs_file_splice_read(struct file *in, loff_t *ppos,
				     struct pipe_inode_info *pipe,
				     size_t len, unsigned int flags)
{
	struct p9_fid *fid = in->private_data;

	p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
		 fid->fid, len, *ppos);

	if (fid->mode & P9L_DIRECT)
		return copy_splice_read(in, ppos, pipe, len, flags);
	return filemap_splice_read(in, ppos, pipe, len, flags);
}

/**
 * v9fs_file_write_iter - write to a file
 * @iocb: The operation parameters
 * @from: The data to write
 *
 */
static ssize_t
v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	struct file *file = iocb->ki_filp;
	struct p9_fid *fid = file->private_data;
	ssize_t retval;
	loff_t origin;
	int err = 0;

	p9_debug(P9_DEBUG_VFS, "fid %d\n", fid->fid);

	if (!(fid->mode & (P9L_DIRECT | P9L_NOWRITECACHE))) {
		p9_debug(P9_DEBUG_CACHE, "(cached)\n");
		return generic_file_write_iter(iocb, from);
	}

	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;
	struct inode *inode = file_inode(filp);
	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);

	p9_debug(P9_DEBUG_MMAP, "filp :%p\n", filp);

	if (!(v9ses->cache & CACHE_WRITEBACK)) {
		p9_debug(P9_DEBUG_CACHE, "(read-only mmap mode)");
		return generic_file_readonly_mmap(filp, vma);
	}

	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 folio *folio = page_folio(vmf->page);
	struct file *filp = vmf->vma->vm_file;
	struct inode *inode = file_inode(filp);


	p9_debug(P9_DEBUG_VFS, "folio %p fid %lx\n",
		 folio, (unsigned long)filp->private_data);

	/* Wait for the page to be written to the cache before we allow it to
	 * be modified.  We then assume the entire page will need writing back.
	 */
#ifdef CONFIG_9P_FSCACHE
	if (folio_test_fscache(folio) &&
	    folio_wait_fscache_killable(folio) < 0)
		return VM_FAULT_NOPAGE;
#endif

	/* Update file times before taking page lock */
	file_update_time(filp);

	if (folio_lock_killable(folio) < 0)
		return VM_FAULT_RETRY;
	if (folio_mapping(folio) != inode->i_mapping)
		goto out_unlock;
	folio_wait_stable(folio);

	return VM_FAULT_LOCKED;
out_unlock:
	folio_unlock(folio);
	return VM_FAULT_NOPAGE;
}

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 = (loff_t)vma->vm_pgoff * PAGE_SIZE,
		 /* absolute end, byte at end included */
		.range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
			(vma->vm_end - vma->vm_start - 1),
	};

	if (!(vma->vm_flags & VM_SHARED))
		return;

	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);

	inode = file_inode(vma->vm_file);
	filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
}

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_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,
	.splice_read = v9fs_file_splice_read,
	.splice_write = iter_file_splice_write,
	.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 = v9fs_file_mmap,
	.splice_read = v9fs_file_splice_read,
	.splice_write = iter_file_splice_write,
	.fsync = v9fs_file_fsync_dotl,
};
Commit	Line	Data
1f327613	1	// SPDX-License-Identifier: GPL-2.0-only
e69e7fe5	2	/*
e69e7fe5 EVH	3	* This file contians vfs file ops for 9P2000.
	4	*
	5	* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
	6	* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
e69e7fe5 EVH	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/errno.h>
	11	#include <linux/fs.h>
5970e15d	12	#include <linux/filelock.h>
914e2637	13	#include <linux/sched.h>
e69e7fe5 EVH	14	#include <linux/file.h>
	15	#include <linux/stat.h>
	16	#include <linux/string.h>
e69e7fe5	17	#include <linux/list.h>
637d020a	18	#include <linux/pagemap.h>
a099027c	19	#include <linux/utsname.h>
7c0f6ba6	20	#include <linux/uaccess.h>
070b3656	21	#include <linux/uio.h>
ce85dd58	22	#include <linux/slab.h>
bd238fb4 LI	23	#include <net/9p/9p.h>
bd238fb4 LI	24	#include <net/9p/client.h>
e69e7fe5	25
e69e7fe5	26	#include "v9fs.h"
e69e7fe5 EVH	27	#include "v9fs_vfs.h"
e69e7fe5 EVH	28	#include "fid.h"
60e78d2c	29	#include "cache.h"
e69e7fe5	30
fb89b45c	31	static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
7263cebe	32
e69e7fe5 EVH	33	/**
	34	* v9fs_file_open - open a file (or directory)
	35	* @inode: inode to be opened
	36	* @file: file being opened
	37	*
	38	*/
	39
	40	int v9fs_file_open(struct inode inode, struct file file)
	41	{
6a3124a3	42	int err;
bd238fb4	43	struct v9fs_session_info *v9ses;
1543b4c5	44	struct p9_fid *fid;
bd238fb4	45	int omode;
e69e7fe5	46
5d385153	47	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
bd238fb4	48	v9ses = v9fs_inode2v9ses(inode);
ef56547e	49	if (v9fs_proto_dotl(v9ses))
f88657ce	50	omode = v9fs_open_to_dotl_flags(file->f_flags);
ef56547e MK	51	else
	52	omode = v9fs_uflags2omode(file->f_flags,
	53	v9fs_proto_dotu(v9ses));
bd238fb4 LI	54	fid = file->private_data;
bd238fb4 LI	55	if (!fid) {
b403f0e3	56	fid = v9fs_fid_clone(file_dentry(file));
bd238fb4 LI	57	if (IS_ERR(fid))
	58	return PTR_ERR(fid);
	59
4eb31178	60	if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) {
1543b4c5 EVH	61	int writeback_omode = (omode & ~P9_OWRITE) \| P9_ORDWR;
	62
	63	p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n");
	64	err = p9_client_open(fid, writeback_omode);
	65	if (err < 0) {
	66	p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n");
	67	err = p9_client_open(fid, omode);
	68	fid->mode \|= P9L_DIRECT;
	69	}
	70	} else {
	71	err = p9_client_open(fid, omode);
	72	}
9523a841	73	if (err < 0) {
b48dbb99	74	p9_fid_put(fid);
bd238fb4 LI	75	return err;
bd238fb4 LI	76	}
ef56547e MK	77	if ((file->f_flags & O_APPEND) &&
ef56547e MK	78	(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
2e4bef41	79	generic_file_llseek(file, 0, SEEK_END);
dafbe689 DM	80
dafbe689 DM	81	file->private_data = fid;
6a3124a3	82	}
e69e7fe5	83
344504e9	84	#ifdef CONFIG_9P_FSCACHE
4eb31178 EVH	85	if (v9ses->cache & CACHE_FSCACHE)
4eb31178 EVH	86	fscache_use_cookie(v9fs_inode_cookie(V9FS_I(inode)),
24e42e32	87	file->f_mode & FMODE_WRITE);
344504e9	88	#endif
1543b4c5	89	v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
dafbe689	90	v9fs_open_fid_add(inode, &fid);
6a3124a3	91	return 0;
e69e7fe5 EVH	92	}
	93
	94	/**
	95	* v9fs_file_lock - lock a file (or directory)
ee443996 EVH	96	* @filp: file to be locked
	97	* @cmd: lock command
	98	* @fl: file lock structure
e69e7fe5	99	*
ee443996	100	* Bugs: this looks like a local only lock, we should extend into 9P
e69e7fe5 EVH	101	* by using open exclusive
	102	*/
	103
	104	static int v9fs_file_lock(struct file filp, int cmd, struct file_lock fl)
	105	{
496ad9aa	106	struct inode *inode = file_inode(filp);
e69e7fe5	107
5d385153	108	p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
e69e7fe5	109
e69e7fe5	110	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
28fd1298	111	filemap_write_and_wait(inode->i_mapping);
fc0ecff6	112	invalidate_mapping_pages(&inode->i_data, 0, -1);
e69e7fe5 EVH	113	}
e69e7fe5 EVH	114
90d6cf34	115	return 0;
e69e7fe5 EVH	116	}
e69e7fe5 EVH	117
a099027c MK	118	static int v9fs_file_do_lock(struct file filp, int cmd, struct file_lock fl)
	119	{
	120	struct p9_flock flock;
	121	struct p9_fid *fid;
5c4086b8	122	uint8_t status = P9_LOCK_ERROR;
a099027c MK	123	int res = 0;
a099027c MK	124	unsigned char fl_type;
5e172f75	125	struct v9fs_session_info *v9ses;
a099027c MK	126
	127	fid = filp->private_data;
	128	BUG_ON(fid == NULL);
	129
a7a427d1	130	BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX);
a099027c	131
4f656367	132	res = locks_lock_file_wait(filp, fl);
a099027c MK	133	if (res < 0)
	134	goto out;
	135
	136	/* convert posix lock to p9 tlock args */
	137	memset(&flock, 0, sizeof(flock));
51b8b4fb JG	138	/* map the lock type */
	139	switch (fl->fl_type) {
	140	case F_RDLCK:
	141	flock.type = P9_LOCK_TYPE_RDLCK;
	142	break;
	143	case F_WRLCK:
	144	flock.type = P9_LOCK_TYPE_WRLCK;
	145	break;
	146	case F_UNLCK:
	147	flock.type = P9_LOCK_TYPE_UNLCK;
	148	break;
	149	}
a099027c MK	150	flock.start = fl->fl_start;
	151	if (fl->fl_end == OFFSET_MAX)
	152	flock.length = 0;
	153	else
	154	flock.length = fl->fl_end - fl->fl_start + 1;
	155	flock.proc_id = fl->fl_pid;
50192abe	156	flock.client_id = fid->clnt->name;
a099027c MK	157	if (IS_SETLKW(cmd))
	158	flock.flags = P9_LOCK_FLAGS_BLOCK;
	159
5e172f75 DRCS	160	v9ses = v9fs_inode2v9ses(file_inode(filp));
5e172f75 DRCS	161
a099027c MK	162	/*
	163	* if its a blocked request and we get P9_LOCK_BLOCKED as the status
	164	* for lock request, keep on trying
	165	*/
	166	for (;;) {
	167	res = p9_client_lock_dotl(fid, &flock, &status);
	168	if (res < 0)
ad80492d	169	goto out_unlock;
a099027c MK	170
	171	if (status != P9_LOCK_BLOCKED)
	172	break;
	173	if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd))
	174	break;
5e172f75 DRCS	175	if (schedule_timeout_interruptible(v9ses->session_lock_timeout)
5e172f75 DRCS	176	!= 0)
a0ea787b	177	break;
b4dc44b3 DM	178	/*
	179	* p9_client_lock_dotl overwrites flock.client_id with the
	180	* server message, free and reuse the client name
	181	*/
	182	if (flock.client_id != fid->clnt->name) {
	183	kfree(flock.client_id);
	184	flock.client_id = fid->clnt->name;
	185	}
a099027c MK	186	}
	187
	188	/* map 9p status to VFS status */
	189	switch (status) {
	190	case P9_LOCK_SUCCESS:
	191	res = 0;
	192	break;
	193	case P9_LOCK_BLOCKED:
	194	res = -EAGAIN;
	195	break;
b642f726 KS	196	default:
b642f726 KS	197	WARN_ONCE(1, "unknown lock status code: %d\n", status);
df561f66	198	fallthrough;
a099027c MK	199	case P9_LOCK_ERROR:
	200	case P9_LOCK_GRACE:
	201	res = -ENOLCK;
	202	break;
a099027c MK	203	}
a099027c MK	204
ad80492d	205	out_unlock:
a099027c MK	206	/*
	207	* incase server returned error for lock request, revert
	208	* it locally
	209	*/
	210	if (res < 0 && fl->fl_type != F_UNLCK) {
	211	fl_type = fl->fl_type;
	212	fl->fl_type = F_UNLCK;
b6478740	213	/* Even if this fails we want to return the remote error */
2e3078af	214	locks_lock_file_wait(filp, fl);
a099027c MK	215	fl->fl_type = fl_type;
a099027c MK	216	}
b4dc44b3 DM	217	if (flock.client_id != fid->clnt->name)
b4dc44b3 DM	218	kfree(flock.client_id);
a099027c MK	219	out:
	220	return res;
	221	}
	222
1d769cd1 MK	223	static int v9fs_file_getlock(struct file filp, struct file_lock fl)
	224	{
	225	struct p9_getlock glock;
	226	struct p9_fid *fid;
	227	int res = 0;
	228
	229	fid = filp->private_data;
	230	BUG_ON(fid == NULL);
	231
	232	posix_test_lock(filp, fl);
	233	/*
	234	* if we have a conflicting lock locally, no need to validate
	235	* with server
	236	*/
	237	if (fl->fl_type != F_UNLCK)
	238	return res;
	239
	240	/* convert posix lock to p9 tgetlock args */
	241	memset(&glock, 0, sizeof(glock));
51b8b4fb	242	glock.type = P9_LOCK_TYPE_UNLCK;
1d769cd1 MK	243	glock.start = fl->fl_start;
	244	if (fl->fl_end == OFFSET_MAX)
	245	glock.length = 0;
	246	else
	247	glock.length = fl->fl_end - fl->fl_start + 1;
	248	glock.proc_id = fl->fl_pid;
50192abe	249	glock.client_id = fid->clnt->name;
1d769cd1 MK	250
	251	res = p9_client_getlock_dotl(fid, &glock);
	252	if (res < 0)
b4dc44b3	253	goto out;
51b8b4fb JG	254	/* map 9p lock type to os lock type */
	255	switch (glock.type) {
	256	case P9_LOCK_TYPE_RDLCK:
	257	fl->fl_type = F_RDLCK;
	258	break;
	259	case P9_LOCK_TYPE_WRLCK:
	260	fl->fl_type = F_WRLCK;
	261	break;
	262	case P9_LOCK_TYPE_UNLCK:
	263	fl->fl_type = F_UNLCK;
	264	break;
	265	}
	266	if (glock.type != P9_LOCK_TYPE_UNLCK) {
1d769cd1 MK	267	fl->fl_start = glock.start;
	268	if (glock.length == 0)
	269	fl->fl_end = OFFSET_MAX;
	270	else
	271	fl->fl_end = glock.start + glock.length - 1;
9d5b86ac	272	fl->fl_pid = -glock.proc_id;
51b8b4fb	273	}
b4dc44b3 DM	274	out:
	275	if (glock.client_id != fid->clnt->name)
	276	kfree(glock.client_id);
1d769cd1 MK	277	return res;
	278	}
	279
a099027c MK	280	/**
	281	* v9fs_file_lock_dotl - lock a file (or directory)
	282	* @filp: file to be locked
	283	* @cmd: lock command
	284	* @fl: file lock structure
	285	*
	286	*/
	287
	288	static int v9fs_file_lock_dotl(struct file filp, int cmd, struct file_lock fl)
	289	{
496ad9aa	290	struct inode *inode = file_inode(filp);
a099027c MK	291	int ret = -ENOLCK;
a099027c MK	292
4b8e9923 AV	293	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
4b8e9923 AV	294	filp, cmd, fl, filp);
a099027c	295
a099027c MK	296	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
	297	filemap_write_and_wait(inode->i_mapping);
	298	invalidate_mapping_pages(&inode->i_data, 0, -1);
	299	}
	300
	301	if (IS_SETLK(cmd) \|\| IS_SETLKW(cmd))
	302	ret = v9fs_file_do_lock(filp, cmd, fl);
1d769cd1 MK	303	else if (IS_GETLK(cmd))
1d769cd1 MK	304	ret = v9fs_file_getlock(filp, fl);
a099027c MK	305	else
a099027c MK	306	ret = -EINVAL;
a099027c MK	307	return ret;
	308	}
	309
	310	/**
	311	* v9fs_file_flock_dotl - lock a file
	312	* @filp: file to be locked
	313	* @cmd: lock command
	314	* @fl: file lock structure
	315	*
	316	*/
	317
	318	static int v9fs_file_flock_dotl(struct file *filp, int cmd,
	319	struct file_lock *fl)
	320	{
496ad9aa	321	struct inode *inode = file_inode(filp);
a099027c MK	322	int ret = -ENOLCK;
a099027c MK	323
4b8e9923 AV	324	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
4b8e9923 AV	325	filp, cmd, fl, filp);
a099027c	326
a099027c MK	327	if (!(fl->fl_flags & FL_FLOCK))
	328	goto out_err;
	329
	330	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
	331	filemap_write_and_wait(inode->i_mapping);
	332	invalidate_mapping_pages(&inode->i_data, 0, -1);
	333	}
	334	/* Convert flock to posix lock */
a099027c MK	335	fl->fl_flags \|= FL_POSIX;
	336	fl->fl_flags ^= FL_FLOCK;
	337
	338	if (IS_SETLK(cmd) \| IS_SETLKW(cmd))
	339	ret = v9fs_file_do_lock(filp, cmd, fl);
	340	else
	341	ret = -EINVAL;
	342	out_err:
	343	return ret;
	344	}
	345
fbedadc1	346	/**
bc868036 DH	347	* v9fs_file_read_iter - read from a file
	348	* @iocb: The operation parameters
	349	* @to: The buffer to read into
fbedadc1 EVH	350	*
fbedadc1 EVH	351	*/
e69e7fe5	352	static ssize_t
e494b6b5	353	v9fs_file_read_iter(struct kiocb iocb, struct iov_iter to)
e69e7fe5	354	{
e494b6b5	355	struct p9_fid *fid = iocb->ki_filp->private_data;
b5ac1fb2	356	int ret, err = 0;
e69e7fe5	357
1543b4c5 EVH	358	p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
1543b4c5 EVH	359	fid->fid, iov_iter_count(to), iocb->ki_pos);
fbedadc1	360
1543b4c5 EVH	361	if (!(fid->mode & P9L_DIRECT)) {
1543b4c5 EVH	362	p9_debug(P9_DEBUG_VFS, "(cached)\n");
d9bc0d11	363	return generic_file_read_iter(iocb, to);
1543b4c5	364	}
d9bc0d11	365
52cbee2a SA	366	if (iocb->ki_filp->f_flags & O_NONBLOCK)
	367	ret = p9_client_read_once(fid, iocb->ki_pos, to, &err);
	368	else
	369	ret = p9_client_read(fid, iocb->ki_pos, to, &err);
e1200fe6 AV	370	if (!ret)
e1200fe6 AV	371	return err;
e69e7fe5	372
e494b6b5	373	iocb->ki_pos += ret;
bd238fb4	374	return ret;
e69e7fe5 EVH	375	}
e69e7fe5 EVH	376
c829d0bd DH	377	/*
	378	* v9fs_file_splice_read - splice-read from a file
	379	* @in: The 9p file to read from
	380	* @ppos: Where to find/update the file position
	381	* @pipe: The pipe to splice into
	382	* @len: The maximum amount of data to splice
	383	* @flags: SPLICE_F_* flags
	384	*/
	385	static ssize_t v9fs_file_splice_read(struct file in, loff_t ppos,
	386	struct pipe_inode_info *pipe,
	387	size_t len, unsigned int flags)
	388	{
	389	struct p9_fid *fid = in->private_data;
	390
	391	p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n",
	392	fid->fid, len, *ppos);
	393
	394	if (fid->mode & P9L_DIRECT)
	395	return copy_splice_read(in, ppos, pipe, len, flags);
	396	return filemap_splice_read(in, ppos, pipe, len, flags);
	397	}
	398
17311779	399	/**
bc868036 DH	400	* v9fs_file_write_iter - write to a file
	401	* @iocb: The operation parameters
	402	* @from: The data to write
17311779 AK	403	*
	404	*/
	405	static ssize_t
e494b6b5	406	v9fs_file_write_iter(struct kiocb iocb, struct iov_iter from)
17311779	407	{
e494b6b5	408	struct file *file = iocb->ki_filp;
1543b4c5	409	struct p9_fid *fid = file->private_data;
3309dd04 AV	410	ssize_t retval;
3309dd04 AV	411	loff_t origin;
c711a6b1	412	int err = 0;
d9bc0d11	413
1543b4c5 EVH	414	p9_debug(P9_DEBUG_VFS, "fid %d\n", fid->fid);
	415
	416	if (!(fid->mode & (P9L_DIRECT \| P9L_NOWRITECACHE))) {
	417	p9_debug(P9_DEBUG_CACHE, "(cached)\n");
d9bc0d11	418	return generic_file_write_iter(iocb, from);
1543b4c5	419	}
17311779	420
3309dd04 AV	421	retval = generic_write_checks(iocb, from);
3309dd04 AV	422	if (retval <= 0)
c711a6b1 AV	423	return retval;
c711a6b1 AV	424
3309dd04 AV	425	origin = iocb->ki_pos;
3309dd04 AV	426	retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
c711a6b1	427	if (retval > 0) {
e494b6b5	428	struct inode *inode = file_inode(file);
c711a6b1 AV	429	loff_t i_size;
c711a6b1 AV	430	unsigned long pg_start, pg_end;
6e195b0f	431
09cbfeaf KS	432	pg_start = origin >> PAGE_SHIFT;
09cbfeaf KS	433	pg_end = (origin + retval - 1) >> PAGE_SHIFT;
c711a6b1 AV	434	if (inode->i_mapping && inode->i_mapping->nrpages)
	435	invalidate_inode_pages2_range(inode->i_mapping,
	436	pg_start, pg_end);
3309dd04	437	iocb->ki_pos += retval;
c711a6b1	438	i_size = i_size_read(inode);
3309dd04 AV	439	if (iocb->ki_pos > i_size) {
3309dd04 AV	440	inode_add_bytes(inode, iocb->ki_pos - i_size);
5e3cc1ee HT	441	/*
	442	* Need to serialize against i_size_write() in
	443	* v9fs_stat2inode()
	444	*/
	445	v9fs_i_size_write(inode, iocb->ki_pos);
c711a6b1 AV	446	}
	447	return retval;
	448	}
	449	return err;
e69e7fe5 EVH	450	}
e69e7fe5 EVH	451
02c24a82 JB	452	static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
02c24a82 JB	453	int datasync)
7a4439c4 MK	454	{
7a4439c4 MK	455	struct p9_fid *fid;
02c24a82	456	struct inode *inode = filp->f_mapping->host;
7a4439c4 MK	457	struct p9_wstat wstat;
	458	int retval;
	459
3b49c9a1	460	retval = file_write_and_wait_range(filp, start, end);
02c24a82 JB	461	if (retval)
	462	return retval;
	463
5955102c	464	inode_lock(inode);
5d385153	465	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
7a4439c4 MK	466
	467	fid = filp->private_data;
	468	v9fs_blank_wstat(&wstat);
	469
	470	retval = p9_client_wstat(fid, &wstat);
5955102c	471	inode_unlock(inode);
02c24a82	472
7a4439c4 MK	473	return retval;
	474	}
	475
02c24a82 JB	476	int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
02c24a82 JB	477	int datasync)
920e65dc VJJ	478	{
920e65dc VJJ	479	struct p9_fid *fid;
02c24a82	480	struct inode *inode = filp->f_mapping->host;
920e65dc VJJ	481	int retval;
920e65dc VJJ	482
3b49c9a1	483	retval = file_write_and_wait_range(filp, start, end);
02c24a82 JB	484	if (retval)
	485	return retval;
	486
5955102c	487	inode_lock(inode);
5d385153	488	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
920e65dc VJJ	489
	490	fid = filp->private_data;
	491
b165d601	492	retval = p9_client_fsync(fid, datasync);
5955102c	493	inode_unlock(inode);
02c24a82	494
920e65dc VJJ	495	return retval;
	496	}
	497
7263cebe	498	static int
fb89b45c	499	v9fs_file_mmap(struct file filp, struct vm_area_struct vma)
7263cebe AK	500	{
7263cebe AK	501	int retval;
d9bc0d11	502	struct inode *inode = file_inode(filp);
d9bc0d11	503	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
1543b4c5 EVH	504
1543b4c5 EVH	505	p9_debug(P9_DEBUG_MMAP, "filp :%p\n", filp);
fb89b45c	506
4eb31178	507	if (!(v9ses->cache & CACHE_WRITEBACK)) {
75b39682	508	p9_debug(P9_DEBUG_CACHE, "(read-only mmap mode)");
d9bc0d11 EVH	509	return generic_file_readonly_mmap(filp, vma);
	510	}
	511
fb89b45c DM	512	retval = generic_file_mmap(filp, vma);
	513	if (!retval)
	514	vma->vm_ops = &v9fs_mmap_file_vm_ops;
	515
	516	return retval;
	517	}
	518
fe6340e2	519	static vm_fault_t
11bac800	520	v9fs_vm_page_mkwrite(struct vm_fault *vmf)
7263cebe	521	{
78525c74	522	struct folio *folio = page_folio(vmf->page);
11bac800	523	struct file *filp = vmf->vma->vm_file;
496ad9aa	524	struct inode *inode = file_inode(filp);
7263cebe AK	525
7263cebe AK	526
78525c74 DH	527	p9_debug(P9_DEBUG_VFS, "folio %p fid %lx\n",
78525c74 DH	528	folio, (unsigned long)filp->private_data);
7263cebe	529
eb497943 DH	530	/* Wait for the page to be written to the cache before we allow it to
	531	* be modified. We then assume the entire page will need writing back.
	532	*/
	533	#ifdef CONFIG_9P_FSCACHE
78525c74 DH	534	if (folio_test_fscache(folio) &&
	535	folio_wait_fscache_killable(folio) < 0)
	536	return VM_FAULT_NOPAGE;
eb497943 DH	537	#endif
eb497943 DH	538
120c2bca JK	539	/* Update file times before taking page lock */
	540	file_update_time(filp);
	541
78525c74	542	if (folio_lock_killable(folio) < 0)
eb497943	543	return VM_FAULT_RETRY;
78525c74	544	if (folio_mapping(folio) != inode->i_mapping)
7263cebe	545	goto out_unlock;
78525c74	546	folio_wait_stable(folio);
7263cebe AK	547
	548	return VM_FAULT_LOCKED;
	549	out_unlock:
78525c74	550	folio_unlock(folio);
7263cebe AK	551	return VM_FAULT_NOPAGE;
	552	}
	553
fb89b45c DM	554	static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
	555	{
	556	struct inode *inode;
	557
	558	struct writeback_control wbc = {
	559	.nr_to_write = LONG_MAX,
	560	.sync_mode = WB_SYNC_ALL,
f5f7ab16	561	.range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE,
fb89b45c	562	/* absolute end, byte at end included */
f5f7ab16	563	.range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE +
fb89b45c DM	564	(vma->vm_end - vma->vm_start - 1),
	565	};
	566
c87a37eb CX	567	if (!(vma->vm_flags & VM_SHARED))
c87a37eb CX	568	return;
fb89b45c DM	569
	570	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
	571
	572	inode = file_inode(vma->vm_file);
25d23cd0	573	filemap_fdatawrite_wbc(inode->i_mapping, &wbc);
fb89b45c DM	574	}
fb89b45c DM	575
fb89b45c DM	576	static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
	577	.close = v9fs_mmap_vm_close,
	578	.fault = filemap_fault,
f1820361	579	.map_pages = filemap_map_pages,
fb89b45c	580	.page_mkwrite = v9fs_vm_page_mkwrite,
fb89b45c DM	581	};
fb89b45c DM	582
4b6f5d20	583	const struct file_operations v9fs_file_operations = {
e69e7fe5	584	.llseek = generic_file_llseek,
e494b6b5 AV	585	.read_iter = v9fs_file_read_iter,
e494b6b5 AV	586	.write_iter = v9fs_file_write_iter,
e69e7fe5 EVH	587	.open = v9fs_file_open,
	588	.release = v9fs_dir_release,
	589	.lock = v9fs_file_lock,
14b8869f	590	.mmap = generic_file_readonly_mmap,
c829d0bd	591	.splice_read = v9fs_file_splice_read,
960f4f8a	592	.splice_write = iter_file_splice_write,
7a4439c4	593	.fsync = v9fs_file_fsync,
e69e7fe5	594	};
9b6533c9 SK	595
	596	const struct file_operations v9fs_file_operations_dotl = {
	597	.llseek = generic_file_llseek,
e494b6b5 AV	598	.read_iter = v9fs_file_read_iter,
e494b6b5 AV	599	.write_iter = v9fs_file_write_iter,
9b6533c9 SK	600	.open = v9fs_file_open,
9b6533c9 SK	601	.release = v9fs_dir_release,
a099027c MK	602	.lock = v9fs_file_lock_dotl,
a099027c MK	603	.flock = v9fs_file_flock_dotl,
d9bc0d11	604	.mmap = v9fs_file_mmap,
c829d0bd	605	.splice_read = v9fs_file_splice_read,
960f4f8a	606	.splice_write = iter_file_splice_write,
fb89b45c DM	607	.fsync = v9fs_file_fsync_dotl,
fb89b45c DM	608	};