![Miklos Szeredi](/assets/img/avatar_default.png)
Extract common code for setting i_size in write functions into a common helper. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1246 lines
30 KiB
C
1246 lines
30 KiB
C
/*
|
|
FUSE: Filesystem in Userspace
|
|
Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
|
|
|
|
This program can be distributed under the terms of the GNU GPL.
|
|
See the file COPYING.
|
|
*/
|
|
|
|
#include "fuse_i.h"
|
|
|
|
#include <linux/pagemap.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
|
|
static const struct file_operations fuse_direct_io_file_operations;
|
|
|
|
static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
|
|
struct fuse_open_out *outargp)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_open_in inarg;
|
|
struct fuse_req *req;
|
|
int err;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
|
|
if (!fc->atomic_o_trunc)
|
|
inarg.flags &= ~O_TRUNC;
|
|
req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(*outargp);
|
|
req->out.args[0].value = outargp;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
|
|
return err;
|
|
}
|
|
|
|
struct fuse_file *fuse_file_alloc(void)
|
|
{
|
|
struct fuse_file *ff;
|
|
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
|
|
if (ff) {
|
|
ff->reserved_req = fuse_request_alloc();
|
|
if (!ff->reserved_req) {
|
|
kfree(ff);
|
|
ff = NULL;
|
|
} else {
|
|
INIT_LIST_HEAD(&ff->write_entry);
|
|
atomic_set(&ff->count, 0);
|
|
}
|
|
}
|
|
return ff;
|
|
}
|
|
|
|
void fuse_file_free(struct fuse_file *ff)
|
|
{
|
|
fuse_request_free(ff->reserved_req);
|
|
kfree(ff);
|
|
}
|
|
|
|
static struct fuse_file *fuse_file_get(struct fuse_file *ff)
|
|
{
|
|
atomic_inc(&ff->count);
|
|
return ff;
|
|
}
|
|
|
|
static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
dput(req->misc.release.dentry);
|
|
mntput(req->misc.release.vfsmount);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
static void fuse_file_put(struct fuse_file *ff)
|
|
{
|
|
if (atomic_dec_and_test(&ff->count)) {
|
|
struct fuse_req *req = ff->reserved_req;
|
|
struct inode *inode = req->misc.release.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
req->end = fuse_release_end;
|
|
request_send_background(fc, req);
|
|
kfree(ff);
|
|
}
|
|
}
|
|
|
|
void fuse_finish_open(struct inode *inode, struct file *file,
|
|
struct fuse_file *ff, struct fuse_open_out *outarg)
|
|
{
|
|
if (outarg->open_flags & FOPEN_DIRECT_IO)
|
|
file->f_op = &fuse_direct_io_file_operations;
|
|
if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
|
|
invalidate_inode_pages2(inode->i_mapping);
|
|
ff->fh = outarg->fh;
|
|
file->private_data = fuse_file_get(ff);
|
|
}
|
|
|
|
int fuse_open_common(struct inode *inode, struct file *file, int isdir)
|
|
{
|
|
struct fuse_open_out outarg;
|
|
struct fuse_file *ff;
|
|
int err;
|
|
|
|
/* VFS checks this, but only _after_ ->open() */
|
|
if (file->f_flags & O_DIRECT)
|
|
return -EINVAL;
|
|
|
|
err = generic_file_open(inode, file);
|
|
if (err)
|
|
return err;
|
|
|
|
ff = fuse_file_alloc();
|
|
if (!ff)
|
|
return -ENOMEM;
|
|
|
|
err = fuse_send_open(inode, file, isdir, &outarg);
|
|
if (err)
|
|
fuse_file_free(ff);
|
|
else {
|
|
if (isdir)
|
|
outarg.open_flags &= ~FOPEN_DIRECT_IO;
|
|
fuse_finish_open(inode, file, ff, &outarg);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
|
|
{
|
|
struct fuse_req *req = ff->reserved_req;
|
|
struct fuse_release_in *inarg = &req->misc.release.in;
|
|
|
|
inarg->fh = ff->fh;
|
|
inarg->flags = flags;
|
|
req->in.h.opcode = opcode;
|
|
req->in.h.nodeid = nodeid;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(struct fuse_release_in);
|
|
req->in.args[0].value = inarg;
|
|
}
|
|
|
|
int fuse_release_common(struct inode *inode, struct file *file, int isdir)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
if (ff) {
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req = ff->reserved_req;
|
|
|
|
fuse_release_fill(ff, get_node_id(inode), file->f_flags,
|
|
isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
|
|
|
|
/* Hold vfsmount and dentry until release is finished */
|
|
req->misc.release.vfsmount = mntget(file->f_path.mnt);
|
|
req->misc.release.dentry = dget(file->f_path.dentry);
|
|
|
|
spin_lock(&fc->lock);
|
|
list_del(&ff->write_entry);
|
|
spin_unlock(&fc->lock);
|
|
/*
|
|
* Normally this will send the RELEASE request,
|
|
* however if some asynchronous READ or WRITE requests
|
|
* are outstanding, the sending will be delayed
|
|
*/
|
|
fuse_file_put(ff);
|
|
}
|
|
|
|
/* Return value is ignored by VFS */
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_open(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_open_common(inode, file, 0);
|
|
}
|
|
|
|
static int fuse_release(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_release_common(inode, file, 0);
|
|
}
|
|
|
|
/*
|
|
* Scramble the ID space with XTEA, so that the value of the files_struct
|
|
* pointer is not exposed to userspace.
|
|
*/
|
|
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
|
|
{
|
|
u32 *k = fc->scramble_key;
|
|
u64 v = (unsigned long) id;
|
|
u32 v0 = v;
|
|
u32 v1 = v >> 32;
|
|
u32 sum = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < 32; i++) {
|
|
v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
|
|
sum += 0x9E3779B9;
|
|
v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
|
|
}
|
|
|
|
return (u64) v0 + ((u64) v1 << 32);
|
|
}
|
|
|
|
/*
|
|
* Check if page is under writeback
|
|
*
|
|
* This is currently done by walking the list of writepage requests
|
|
* for the inode, which can be pretty inefficient.
|
|
*/
|
|
static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_req *req;
|
|
bool found = false;
|
|
|
|
spin_lock(&fc->lock);
|
|
list_for_each_entry(req, &fi->writepages, writepages_entry) {
|
|
pgoff_t curr_index;
|
|
|
|
BUG_ON(req->inode != inode);
|
|
curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
|
|
if (curr_index == index) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* Wait for page writeback to be completed.
|
|
*
|
|
* Since fuse doesn't rely on the VM writeback tracking, this has to
|
|
* use some other means.
|
|
*/
|
|
static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
|
|
{
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_flush(struct file *file, fl_owner_t id)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_req *req;
|
|
struct fuse_flush_in inarg;
|
|
int err;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
if (fc->no_flush)
|
|
return 0;
|
|
|
|
req = fuse_get_req_nofail(fc, file);
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.fh = ff->fh;
|
|
inarg.lock_owner = fuse_lock_owner_id(fc, id);
|
|
req->in.h.opcode = FUSE_FLUSH;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->force = 1;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS) {
|
|
fc->no_flush = 1;
|
|
err = 0;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Wait for all pending writepages on the inode to finish.
|
|
*
|
|
* This is currently done by blocking further writes with FUSE_NOWRITE
|
|
* and waiting for all sent writes to complete.
|
|
*
|
|
* This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
|
|
* could conflict with truncation.
|
|
*/
|
|
static void fuse_sync_writes(struct inode *inode)
|
|
{
|
|
fuse_set_nowrite(inode);
|
|
fuse_release_nowrite(inode);
|
|
}
|
|
|
|
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
|
|
int isdir)
|
|
{
|
|
struct inode *inode = de->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_req *req;
|
|
struct fuse_fsync_in inarg;
|
|
int err;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
|
|
return 0;
|
|
|
|
/*
|
|
* Start writeback against all dirty pages of the inode, then
|
|
* wait for all outstanding writes, before sending the FSYNC
|
|
* request.
|
|
*/
|
|
err = write_inode_now(inode, 0);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_sync_writes(inode);
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.fh = ff->fh;
|
|
inarg.fsync_flags = datasync ? 1 : 0;
|
|
req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS) {
|
|
if (isdir)
|
|
fc->no_fsyncdir = 1;
|
|
else
|
|
fc->no_fsync = 1;
|
|
err = 0;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
|
|
{
|
|
return fuse_fsync_common(file, de, datasync, 0);
|
|
}
|
|
|
|
void fuse_read_fill(struct fuse_req *req, struct file *file,
|
|
struct inode *inode, loff_t pos, size_t count, int opcode)
|
|
{
|
|
struct fuse_read_in *inarg = &req->misc.read_in;
|
|
struct fuse_file *ff = file->private_data;
|
|
|
|
inarg->fh = ff->fh;
|
|
inarg->offset = pos;
|
|
inarg->size = count;
|
|
inarg->flags = file->f_flags;
|
|
req->in.h.opcode = opcode;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(struct fuse_read_in);
|
|
req->in.args[0].value = inarg;
|
|
req->out.argpages = 1;
|
|
req->out.argvar = 1;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = count;
|
|
}
|
|
|
|
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
|
|
struct inode *inode, loff_t pos, size_t count,
|
|
fl_owner_t owner)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
|
|
if (owner != NULL) {
|
|
struct fuse_read_in *inarg = &req->misc.read_in;
|
|
|
|
inarg->read_flags |= FUSE_READ_LOCKOWNER;
|
|
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
|
|
}
|
|
request_send(fc, req);
|
|
return req->out.args[0].size;
|
|
}
|
|
|
|
static int fuse_readpage(struct file *file, struct page *page)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
int err;
|
|
|
|
err = -EIO;
|
|
if (is_bad_inode(inode))
|
|
goto out;
|
|
|
|
/*
|
|
* Page writeback can extend beyond the liftime of the
|
|
* page-cache page, so make sure we read a properly synced
|
|
* page.
|
|
*/
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
|
|
req = fuse_get_req(fc);
|
|
err = PTR_ERR(req);
|
|
if (IS_ERR(req))
|
|
goto out;
|
|
|
|
req->out.page_zeroing = 1;
|
|
req->num_pages = 1;
|
|
req->pages[0] = page;
|
|
fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE,
|
|
NULL);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err)
|
|
SetPageUptodate(page);
|
|
fuse_invalidate_attr(inode); /* atime changed */
|
|
out:
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
int i;
|
|
|
|
fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
|
|
|
|
for (i = 0; i < req->num_pages; i++) {
|
|
struct page *page = req->pages[i];
|
|
if (!req->out.h.error)
|
|
SetPageUptodate(page);
|
|
else
|
|
SetPageError(page);
|
|
unlock_page(page);
|
|
}
|
|
if (req->ff)
|
|
fuse_file_put(req->ff);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
static void fuse_send_readpages(struct fuse_req *req, struct file *file,
|
|
struct inode *inode)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
loff_t pos = page_offset(req->pages[0]);
|
|
size_t count = req->num_pages << PAGE_CACHE_SHIFT;
|
|
req->out.page_zeroing = 1;
|
|
fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
|
|
if (fc->async_read) {
|
|
struct fuse_file *ff = file->private_data;
|
|
req->ff = fuse_file_get(ff);
|
|
req->end = fuse_readpages_end;
|
|
request_send_background(fc, req);
|
|
} else {
|
|
request_send(fc, req);
|
|
fuse_readpages_end(fc, req);
|
|
}
|
|
}
|
|
|
|
struct fuse_fill_data {
|
|
struct fuse_req *req;
|
|
struct file *file;
|
|
struct inode *inode;
|
|
};
|
|
|
|
static int fuse_readpages_fill(void *_data, struct page *page)
|
|
{
|
|
struct fuse_fill_data *data = _data;
|
|
struct fuse_req *req = data->req;
|
|
struct inode *inode = data->inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
|
|
if (req->num_pages &&
|
|
(req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
|
|
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
|
|
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
|
|
fuse_send_readpages(req, data->file, inode);
|
|
data->req = req = fuse_get_req(fc);
|
|
if (IS_ERR(req)) {
|
|
unlock_page(page);
|
|
return PTR_ERR(req);
|
|
}
|
|
}
|
|
req->pages[req->num_pages] = page;
|
|
req->num_pages ++;
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_readpages(struct file *file, struct address_space *mapping,
|
|
struct list_head *pages, unsigned nr_pages)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_fill_data data;
|
|
int err;
|
|
|
|
err = -EIO;
|
|
if (is_bad_inode(inode))
|
|
goto out;
|
|
|
|
data.file = file;
|
|
data.inode = inode;
|
|
data.req = fuse_get_req(fc);
|
|
err = PTR_ERR(data.req);
|
|
if (IS_ERR(data.req))
|
|
goto out;
|
|
|
|
err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
|
|
if (!err) {
|
|
if (data.req->num_pages)
|
|
fuse_send_readpages(data.req, file, inode);
|
|
else
|
|
fuse_put_request(fc, data.req);
|
|
}
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
|
|
unsigned long nr_segs, loff_t pos)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
|
|
if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
|
|
int err;
|
|
/*
|
|
* If trying to read past EOF, make sure the i_size
|
|
* attribute is up-to-date.
|
|
*/
|
|
err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return generic_file_aio_read(iocb, iov, nr_segs, pos);
|
|
}
|
|
|
|
static void fuse_write_fill(struct fuse_req *req, struct file *file,
|
|
struct fuse_file *ff, struct inode *inode,
|
|
loff_t pos, size_t count, int writepage)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
struct fuse_write_out *outarg = &req->misc.write.out;
|
|
|
|
memset(inarg, 0, sizeof(struct fuse_write_in));
|
|
inarg->fh = ff->fh;
|
|
inarg->offset = pos;
|
|
inarg->size = count;
|
|
inarg->write_flags = writepage ? FUSE_WRITE_CACHE : 0;
|
|
inarg->flags = file ? file->f_flags : 0;
|
|
req->in.h.opcode = FUSE_WRITE;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.argpages = 1;
|
|
req->in.numargs = 2;
|
|
if (fc->minor < 9)
|
|
req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
|
|
else
|
|
req->in.args[0].size = sizeof(struct fuse_write_in);
|
|
req->in.args[0].value = inarg;
|
|
req->in.args[1].size = count;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(struct fuse_write_out);
|
|
req->out.args[0].value = outarg;
|
|
}
|
|
|
|
static size_t fuse_send_write(struct fuse_req *req, struct file *file,
|
|
struct inode *inode, loff_t pos, size_t count,
|
|
fl_owner_t owner)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
fuse_write_fill(req, file, file->private_data, inode, pos, count, 0);
|
|
if (owner != NULL) {
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
|
|
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
|
|
}
|
|
request_send(fc, req);
|
|
return req->misc.write.out.size;
|
|
}
|
|
|
|
static int fuse_write_begin(struct file *file, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned flags,
|
|
struct page **pagep, void **fsdata)
|
|
{
|
|
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
|
|
|
|
*pagep = __grab_cache_page(mapping, index);
|
|
if (!*pagep)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void fuse_write_update_size(struct inode *inode, loff_t pos)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
fi->attr_version = ++fc->attr_version;
|
|
if (pos > inode->i_size)
|
|
i_size_write(inode, pos);
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
|
|
static int fuse_buffered_write(struct file *file, struct inode *inode,
|
|
loff_t pos, unsigned count, struct page *page)
|
|
{
|
|
int err;
|
|
size_t nres;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
|
|
struct fuse_req *req;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
/*
|
|
* Make sure writepages on the same page are not mixed up with
|
|
* plain writes.
|
|
*/
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
req->num_pages = 1;
|
|
req->pages[0] = page;
|
|
req->page_offset = offset;
|
|
nres = fuse_send_write(req, file, inode, pos, count, NULL);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err && !nres)
|
|
err = -EIO;
|
|
if (!err) {
|
|
pos += nres;
|
|
fuse_write_update_size(inode, pos);
|
|
if (count == PAGE_CACHE_SIZE)
|
|
SetPageUptodate(page);
|
|
}
|
|
fuse_invalidate_attr(inode);
|
|
return err ? err : nres;
|
|
}
|
|
|
|
static int fuse_write_end(struct file *file, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned copied,
|
|
struct page *page, void *fsdata)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
int res = 0;
|
|
|
|
if (copied)
|
|
res = fuse_buffered_write(file, inode, pos, copied, page);
|
|
|
|
unlock_page(page);
|
|
page_cache_release(page);
|
|
return res;
|
|
}
|
|
|
|
static void fuse_release_user_pages(struct fuse_req *req, int write)
|
|
{
|
|
unsigned i;
|
|
|
|
for (i = 0; i < req->num_pages; i++) {
|
|
struct page *page = req->pages[i];
|
|
if (write)
|
|
set_page_dirty_lock(page);
|
|
put_page(page);
|
|
}
|
|
}
|
|
|
|
static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
|
|
unsigned nbytes, int write)
|
|
{
|
|
unsigned long user_addr = (unsigned long) buf;
|
|
unsigned offset = user_addr & ~PAGE_MASK;
|
|
int npages;
|
|
|
|
/* This doesn't work with nfsd */
|
|
if (!current->mm)
|
|
return -EPERM;
|
|
|
|
nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
|
|
npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
|
|
down_read(¤t->mm->mmap_sem);
|
|
npages = get_user_pages(current, current->mm, user_addr, npages, write,
|
|
0, req->pages, NULL);
|
|
up_read(¤t->mm->mmap_sem);
|
|
if (npages < 0)
|
|
return npages;
|
|
|
|
req->num_pages = npages;
|
|
req->page_offset = offset;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos, int write)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
size_t nmax = write ? fc->max_write : fc->max_read;
|
|
loff_t pos = *ppos;
|
|
ssize_t res = 0;
|
|
struct fuse_req *req;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
while (count) {
|
|
size_t nres;
|
|
size_t nbytes = min(count, nmax);
|
|
int err = fuse_get_user_pages(req, buf, nbytes, !write);
|
|
if (err) {
|
|
res = err;
|
|
break;
|
|
}
|
|
nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
|
|
nbytes = min(count, nbytes);
|
|
if (write)
|
|
nres = fuse_send_write(req, file, inode, pos, nbytes,
|
|
current->files);
|
|
else
|
|
nres = fuse_send_read(req, file, inode, pos, nbytes,
|
|
current->files);
|
|
fuse_release_user_pages(req, !write);
|
|
if (req->out.h.error) {
|
|
if (!res)
|
|
res = req->out.h.error;
|
|
break;
|
|
} else if (nres > nbytes) {
|
|
res = -EIO;
|
|
break;
|
|
}
|
|
count -= nres;
|
|
res += nres;
|
|
pos += nres;
|
|
buf += nres;
|
|
if (nres != nbytes)
|
|
break;
|
|
if (count) {
|
|
fuse_put_request(fc, req);
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
break;
|
|
}
|
|
}
|
|
fuse_put_request(fc, req);
|
|
if (res > 0) {
|
|
if (write)
|
|
fuse_write_update_size(inode, pos);
|
|
*ppos = pos;
|
|
}
|
|
fuse_invalidate_attr(inode);
|
|
|
|
return res;
|
|
}
|
|
|
|
static ssize_t fuse_direct_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return fuse_direct_io(file, buf, count, ppos, 0);
|
|
}
|
|
|
|
static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
ssize_t res;
|
|
/* Don't allow parallel writes to the same file */
|
|
mutex_lock(&inode->i_mutex);
|
|
res = generic_write_checks(file, ppos, &count, 0);
|
|
if (!res)
|
|
res = fuse_direct_io(file, buf, count, ppos, 1);
|
|
mutex_unlock(&inode->i_mutex);
|
|
return res;
|
|
}
|
|
|
|
static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
__free_page(req->pages[0]);
|
|
fuse_file_put(req->ff);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct inode *inode = req->inode;
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
|
|
|
|
list_del(&req->writepages_entry);
|
|
dec_bdi_stat(bdi, BDI_WRITEBACK);
|
|
dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
|
|
bdi_writeout_inc(bdi);
|
|
wake_up(&fi->page_waitq);
|
|
}
|
|
|
|
/* Called under fc->lock, may release and reacquire it */
|
|
static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_inode *fi = get_fuse_inode(req->inode);
|
|
loff_t size = i_size_read(req->inode);
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
|
|
if (!fc->connected)
|
|
goto out_free;
|
|
|
|
if (inarg->offset + PAGE_CACHE_SIZE <= size) {
|
|
inarg->size = PAGE_CACHE_SIZE;
|
|
} else if (inarg->offset < size) {
|
|
inarg->size = size & (PAGE_CACHE_SIZE - 1);
|
|
} else {
|
|
/* Got truncated off completely */
|
|
goto out_free;
|
|
}
|
|
|
|
req->in.args[1].size = inarg->size;
|
|
fi->writectr++;
|
|
request_send_background_locked(fc, req);
|
|
return;
|
|
|
|
out_free:
|
|
fuse_writepage_finish(fc, req);
|
|
spin_unlock(&fc->lock);
|
|
fuse_writepage_free(fc, req);
|
|
spin_lock(&fc->lock);
|
|
}
|
|
|
|
/*
|
|
* If fi->writectr is positive (no truncate or fsync going on) send
|
|
* all queued writepage requests.
|
|
*
|
|
* Called with fc->lock
|
|
*/
|
|
void fuse_flush_writepages(struct inode *inode)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_req *req;
|
|
|
|
while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
|
|
req = list_entry(fi->queued_writes.next, struct fuse_req, list);
|
|
list_del_init(&req->list);
|
|
fuse_send_writepage(fc, req);
|
|
}
|
|
}
|
|
|
|
static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct inode *inode = req->inode;
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
mapping_set_error(inode->i_mapping, req->out.h.error);
|
|
spin_lock(&fc->lock);
|
|
fi->writectr--;
|
|
fuse_writepage_finish(fc, req);
|
|
spin_unlock(&fc->lock);
|
|
fuse_writepage_free(fc, req);
|
|
}
|
|
|
|
static int fuse_writepage_locked(struct page *page)
|
|
{
|
|
struct address_space *mapping = page->mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_file *ff;
|
|
struct page *tmp_page;
|
|
|
|
set_page_writeback(page);
|
|
|
|
req = fuse_request_alloc_nofs();
|
|
if (!req)
|
|
goto err;
|
|
|
|
tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!tmp_page)
|
|
goto err_free;
|
|
|
|
spin_lock(&fc->lock);
|
|
BUG_ON(list_empty(&fi->write_files));
|
|
ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
|
|
req->ff = fuse_file_get(ff);
|
|
spin_unlock(&fc->lock);
|
|
|
|
fuse_write_fill(req, NULL, ff, inode, page_offset(page), 0, 1);
|
|
|
|
copy_highpage(tmp_page, page);
|
|
req->num_pages = 1;
|
|
req->pages[0] = tmp_page;
|
|
req->page_offset = 0;
|
|
req->end = fuse_writepage_end;
|
|
req->inode = inode;
|
|
|
|
inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
|
|
inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
|
|
end_page_writeback(page);
|
|
|
|
spin_lock(&fc->lock);
|
|
list_add(&req->writepages_entry, &fi->writepages);
|
|
list_add_tail(&req->list, &fi->queued_writes);
|
|
fuse_flush_writepages(inode);
|
|
spin_unlock(&fc->lock);
|
|
|
|
return 0;
|
|
|
|
err_free:
|
|
fuse_request_free(req);
|
|
err:
|
|
end_page_writeback(page);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int fuse_writepage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
int err;
|
|
|
|
err = fuse_writepage_locked(page);
|
|
unlock_page(page);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_launder_page(struct page *page)
|
|
{
|
|
int err = 0;
|
|
if (clear_page_dirty_for_io(page)) {
|
|
struct inode *inode = page->mapping->host;
|
|
err = fuse_writepage_locked(page);
|
|
if (!err)
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Write back dirty pages now, because there may not be any suitable
|
|
* open files later
|
|
*/
|
|
static void fuse_vma_close(struct vm_area_struct *vma)
|
|
{
|
|
filemap_write_and_wait(vma->vm_file->f_mapping);
|
|
}
|
|
|
|
/*
|
|
* Wait for writeback against this page to complete before allowing it
|
|
* to be marked dirty again, and hence written back again, possibly
|
|
* before the previous writepage completed.
|
|
*
|
|
* Block here, instead of in ->writepage(), so that the userspace fs
|
|
* can only block processes actually operating on the filesystem.
|
|
*
|
|
* Otherwise unprivileged userspace fs would be able to block
|
|
* unrelated:
|
|
*
|
|
* - page migration
|
|
* - sync(2)
|
|
* - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
|
|
*/
|
|
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct page *page)
|
|
{
|
|
/*
|
|
* Don't use page->mapping as it may become NULL from a
|
|
* concurrent truncate.
|
|
*/
|
|
struct inode *inode = vma->vm_file->f_mapping->host;
|
|
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
return 0;
|
|
}
|
|
|
|
static struct vm_operations_struct fuse_file_vm_ops = {
|
|
.close = fuse_vma_close,
|
|
.fault = filemap_fault,
|
|
.page_mkwrite = fuse_page_mkwrite,
|
|
};
|
|
|
|
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
/*
|
|
* file may be written through mmap, so chain it onto the
|
|
* inodes's write_file list
|
|
*/
|
|
spin_lock(&fc->lock);
|
|
if (list_empty(&ff->write_entry))
|
|
list_add(&ff->write_entry, &fi->write_files);
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
file_accessed(file);
|
|
vma->vm_ops = &fuse_file_vm_ops;
|
|
return 0;
|
|
}
|
|
|
|
static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
|
|
struct file_lock *fl)
|
|
{
|
|
switch (ffl->type) {
|
|
case F_UNLCK:
|
|
break;
|
|
|
|
case F_RDLCK:
|
|
case F_WRLCK:
|
|
if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
|
|
ffl->end < ffl->start)
|
|
return -EIO;
|
|
|
|
fl->fl_start = ffl->start;
|
|
fl->fl_end = ffl->end;
|
|
fl->fl_pid = ffl->pid;
|
|
break;
|
|
|
|
default:
|
|
return -EIO;
|
|
}
|
|
fl->fl_type = ffl->type;
|
|
return 0;
|
|
}
|
|
|
|
static void fuse_lk_fill(struct fuse_req *req, struct file *file,
|
|
const struct file_lock *fl, int opcode, pid_t pid,
|
|
int flock)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_lk_in *arg = &req->misc.lk_in;
|
|
|
|
arg->fh = ff->fh;
|
|
arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
|
|
arg->lk.start = fl->fl_start;
|
|
arg->lk.end = fl->fl_end;
|
|
arg->lk.type = fl->fl_type;
|
|
arg->lk.pid = pid;
|
|
if (flock)
|
|
arg->lk_flags |= FUSE_LK_FLOCK;
|
|
req->in.h.opcode = opcode;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(*arg);
|
|
req->in.args[0].value = arg;
|
|
}
|
|
|
|
static int fuse_getlk(struct file *file, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_lk_out outarg;
|
|
int err;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err)
|
|
err = convert_fuse_file_lock(&outarg.lk, fl);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
|
|
pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
|
|
int err;
|
|
|
|
/* Unlock on close is handled by the flush method */
|
|
if (fl->fl_flags & FL_CLOSE)
|
|
return 0;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
fuse_lk_fill(req, file, fl, opcode, pid, flock);
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
/* locking is restartable */
|
|
if (err == -EINTR)
|
|
err = -ERESTARTSYS;
|
|
fuse_put_request(fc, req);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int err;
|
|
|
|
if (cmd == F_GETLK) {
|
|
if (fc->no_lock) {
|
|
posix_test_lock(file, fl);
|
|
err = 0;
|
|
} else
|
|
err = fuse_getlk(file, fl);
|
|
} else {
|
|
if (fc->no_lock)
|
|
err = posix_lock_file_wait(file, fl);
|
|
else
|
|
err = fuse_setlk(file, fl, 0);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int err;
|
|
|
|
if (fc->no_lock) {
|
|
err = flock_lock_file_wait(file, fl);
|
|
} else {
|
|
/* emulate flock with POSIX locks */
|
|
fl->fl_owner = (fl_owner_t) file;
|
|
err = fuse_setlk(file, fl, 1);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_bmap_in inarg;
|
|
struct fuse_bmap_out outarg;
|
|
int err;
|
|
|
|
if (!inode->i_sb->s_bdev || fc->no_bmap)
|
|
return 0;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return 0;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.block = block;
|
|
inarg.blocksize = inode->i_sb->s_blocksize;
|
|
req->in.h.opcode = FUSE_BMAP;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS)
|
|
fc->no_bmap = 1;
|
|
|
|
return err ? 0 : outarg.block;
|
|
}
|
|
|
|
static const struct file_operations fuse_file_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = do_sync_read,
|
|
.aio_read = fuse_file_aio_read,
|
|
.write = do_sync_write,
|
|
.aio_write = generic_file_aio_write,
|
|
.mmap = fuse_file_mmap,
|
|
.open = fuse_open,
|
|
.flush = fuse_flush,
|
|
.release = fuse_release,
|
|
.fsync = fuse_fsync,
|
|
.lock = fuse_file_lock,
|
|
.flock = fuse_file_flock,
|
|
.splice_read = generic_file_splice_read,
|
|
};
|
|
|
|
static const struct file_operations fuse_direct_io_file_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = fuse_direct_read,
|
|
.write = fuse_direct_write,
|
|
.open = fuse_open,
|
|
.flush = fuse_flush,
|
|
.release = fuse_release,
|
|
.fsync = fuse_fsync,
|
|
.lock = fuse_file_lock,
|
|
.flock = fuse_file_flock,
|
|
/* no mmap and splice_read */
|
|
};
|
|
|
|
static const struct address_space_operations fuse_file_aops = {
|
|
.readpage = fuse_readpage,
|
|
.writepage = fuse_writepage,
|
|
.launder_page = fuse_launder_page,
|
|
.write_begin = fuse_write_begin,
|
|
.write_end = fuse_write_end,
|
|
.readpages = fuse_readpages,
|
|
.set_page_dirty = __set_page_dirty_nobuffers,
|
|
.bmap = fuse_bmap,
|
|
};
|
|
|
|
void fuse_init_file_inode(struct inode *inode)
|
|
{
|
|
inode->i_fop = &fuse_file_operations;
|
|
inode->i_data.a_ops = &fuse_file_aops;
|
|
}
|