1 files changed, 705 insertions, 0 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
new file mode 100644
index 000000000..1ef16bd82
--- /dev/null
+++ b/fs/9p/vfs_file.c
@@ -0,0 +1,705 @@
+/*
+ *  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>
+ *
+ *  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
+ *
+ */
+
+#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 <asm/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->f_path.dentry);
+		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->f_path.dentry);
+		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;
+
+	fid = filp->private_data;
+	BUG_ON(fid == NULL);
+
+	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
+		BUG();
+
+	res = posix_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;
+
+	/*
+	 * 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(P9_LOCK_TIMEOUT) != 0)
+			break;
+	}
+
+	/* 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);
+		/* fallthough */
+	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;
+		res = posix_lock_file_wait(filp, fl);
+		fl->fl_type = fl_type;
+	}
+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)
+		return res;
+	/* 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;
+	}
+	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;
+
+	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_CACHE_SHIFT;
+		pg_end = (origin + retval - 1) >> PAGE_CACHE_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);
+			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 = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	if (retval)
+		return retval;
+
+	mutex_lock(&inode->i_mutex);
+	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);
+	mutex_unlock(&inode->i_mutex);
+
+	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 = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	if (retval)
+		return retval;
+
+	mutex_lock(&inode->i_mutex);
+	p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync);
+
+	fid = filp->private_data;
+
+	retval = p9_client_fsync(fid, datasync);
+	mutex_unlock(&inode->i_mutex);
+
+	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(filp->f_path.dentry);
+		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 int
+v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct v9fs_inode *v9inode;
+	struct page *page = vmf->page;
+	struct file *filp = 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,
+};