v4.19.13 snapshot.
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
new file mode 100644
index 0000000..ab3d5f5
--- /dev/null
+++ b/fs/9p/vfs_file.c
@@ -0,0 +1,718 @@
+/*
+ * 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 <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;
+
+ 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;
+
+ /*
+ * 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;
+ /*
+ * 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);
+ /* 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;
+ /* 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);
+ 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,
+};