mirror of
https://github.com/torvalds/linux.git
synced 2024-12-18 00:53:40 +00:00
2c932d4c91
fuse_get_user_pages() should return error or 0. Otherwise fuse_direct_io
read will not return 0 to indicate that read has completed.
Fixes: 742f992708
("fuse: return patrial success from fuse_direct_io()")
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
3066 lines
74 KiB
C
3066 lines
74 KiB
C
/*
|
|
FUSE: Filesystem in Userspace
|
|
Copyright (C) 2001-2008 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>
|
|
#include <linux/module.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/falloc.h>
|
|
#include <linux/uio.h>
|
|
|
|
static const struct file_operations fuse_direct_io_file_operations;
|
|
|
|
static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
|
|
int opcode, struct fuse_open_out *outargp)
|
|
{
|
|
struct fuse_open_in inarg;
|
|
FUSE_ARGS(args);
|
|
|
|
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;
|
|
args.in.h.opcode = opcode;
|
|
args.in.h.nodeid = nodeid;
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(*outargp);
|
|
args.out.args[0].value = outargp;
|
|
|
|
return fuse_simple_request(fc, &args);
|
|
}
|
|
|
|
struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
|
|
{
|
|
struct fuse_file *ff;
|
|
|
|
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
|
|
if (unlikely(!ff))
|
|
return NULL;
|
|
|
|
ff->fc = fc;
|
|
ff->reserved_req = fuse_request_alloc(0);
|
|
if (unlikely(!ff->reserved_req)) {
|
|
kfree(ff);
|
|
return NULL;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&ff->write_entry);
|
|
atomic_set(&ff->count, 0);
|
|
RB_CLEAR_NODE(&ff->polled_node);
|
|
init_waitqueue_head(&ff->poll_wait);
|
|
|
|
spin_lock(&fc->lock);
|
|
ff->kh = ++fc->khctr;
|
|
spin_unlock(&fc->lock);
|
|
|
|
return ff;
|
|
}
|
|
|
|
void fuse_file_free(struct fuse_file *ff)
|
|
{
|
|
fuse_request_free(ff->reserved_req);
|
|
kfree(ff);
|
|
}
|
|
|
|
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)
|
|
{
|
|
iput(req->misc.release.inode);
|
|
}
|
|
|
|
static void fuse_file_put(struct fuse_file *ff, bool sync)
|
|
{
|
|
if (atomic_dec_and_test(&ff->count)) {
|
|
struct fuse_req *req = ff->reserved_req;
|
|
|
|
if (ff->fc->no_open) {
|
|
/*
|
|
* Drop the release request when client does not
|
|
* implement 'open'
|
|
*/
|
|
__clear_bit(FR_BACKGROUND, &req->flags);
|
|
iput(req->misc.release.inode);
|
|
fuse_put_request(ff->fc, req);
|
|
} else if (sync) {
|
|
__clear_bit(FR_BACKGROUND, &req->flags);
|
|
fuse_request_send(ff->fc, req);
|
|
iput(req->misc.release.inode);
|
|
fuse_put_request(ff->fc, req);
|
|
} else {
|
|
req->end = fuse_release_end;
|
|
__set_bit(FR_BACKGROUND, &req->flags);
|
|
fuse_request_send_background(ff->fc, req);
|
|
}
|
|
kfree(ff);
|
|
}
|
|
}
|
|
|
|
int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
|
|
bool isdir)
|
|
{
|
|
struct fuse_file *ff;
|
|
int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
|
|
|
|
ff = fuse_file_alloc(fc);
|
|
if (!ff)
|
|
return -ENOMEM;
|
|
|
|
ff->fh = 0;
|
|
ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */
|
|
if (!fc->no_open || isdir) {
|
|
struct fuse_open_out outarg;
|
|
int err;
|
|
|
|
err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
|
|
if (!err) {
|
|
ff->fh = outarg.fh;
|
|
ff->open_flags = outarg.open_flags;
|
|
|
|
} else if (err != -ENOSYS || isdir) {
|
|
fuse_file_free(ff);
|
|
return err;
|
|
} else {
|
|
fc->no_open = 1;
|
|
}
|
|
}
|
|
|
|
if (isdir)
|
|
ff->open_flags &= ~FOPEN_DIRECT_IO;
|
|
|
|
ff->nodeid = nodeid;
|
|
file->private_data = fuse_file_get(ff);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_do_open);
|
|
|
|
static void fuse_link_write_file(struct file *file)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
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);
|
|
}
|
|
|
|
void fuse_finish_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (ff->open_flags & FOPEN_DIRECT_IO)
|
|
file->f_op = &fuse_direct_io_file_operations;
|
|
if (!(ff->open_flags & FOPEN_KEEP_CACHE))
|
|
invalidate_inode_pages2(inode->i_mapping);
|
|
if (ff->open_flags & FOPEN_NONSEEKABLE)
|
|
nonseekable_open(inode, file);
|
|
if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
fi->attr_version = ++fc->attr_version;
|
|
i_size_write(inode, 0);
|
|
spin_unlock(&fc->lock);
|
|
fuse_invalidate_attr(inode);
|
|
if (fc->writeback_cache)
|
|
file_update_time(file);
|
|
}
|
|
if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
|
|
fuse_link_write_file(file);
|
|
}
|
|
|
|
int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int err;
|
|
bool lock_inode = (file->f_flags & O_TRUNC) &&
|
|
fc->atomic_o_trunc &&
|
|
fc->writeback_cache;
|
|
|
|
err = generic_file_open(inode, file);
|
|
if (err)
|
|
return err;
|
|
|
|
if (lock_inode)
|
|
inode_lock(inode);
|
|
|
|
err = fuse_do_open(fc, get_node_id(inode), file, isdir);
|
|
|
|
if (!err)
|
|
fuse_finish_open(inode, file);
|
|
|
|
if (lock_inode)
|
|
inode_unlock(inode);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
|
|
{
|
|
struct fuse_conn *fc = ff->fc;
|
|
struct fuse_req *req = ff->reserved_req;
|
|
struct fuse_release_in *inarg = &req->misc.release.in;
|
|
|
|
spin_lock(&fc->lock);
|
|
list_del(&ff->write_entry);
|
|
if (!RB_EMPTY_NODE(&ff->polled_node))
|
|
rb_erase(&ff->polled_node, &fc->polled_files);
|
|
spin_unlock(&fc->lock);
|
|
|
|
wake_up_interruptible_all(&ff->poll_wait);
|
|
|
|
inarg->fh = ff->fh;
|
|
inarg->flags = flags;
|
|
req->in.h.opcode = opcode;
|
|
req->in.h.nodeid = ff->nodeid;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(struct fuse_release_in);
|
|
req->in.args[0].value = inarg;
|
|
}
|
|
|
|
void fuse_release_common(struct file *file, int opcode)
|
|
{
|
|
struct fuse_file *ff;
|
|
struct fuse_req *req;
|
|
|
|
ff = file->private_data;
|
|
if (unlikely(!ff))
|
|
return;
|
|
|
|
req = ff->reserved_req;
|
|
fuse_prepare_release(ff, file->f_flags, opcode);
|
|
|
|
if (ff->flock) {
|
|
struct fuse_release_in *inarg = &req->misc.release.in;
|
|
inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
|
|
inarg->lock_owner = fuse_lock_owner_id(ff->fc,
|
|
(fl_owner_t) file);
|
|
}
|
|
/* Hold inode until release is finished */
|
|
req->misc.release.inode = igrab(file_inode(file));
|
|
|
|
/*
|
|
* Normally this will send the RELEASE request, however if
|
|
* some asynchronous READ or WRITE requests are outstanding,
|
|
* the sending will be delayed.
|
|
*
|
|
* Make the release synchronous if this is a fuseblk mount,
|
|
* synchronous RELEASE is allowed (and desirable) in this case
|
|
* because the server can be trusted not to screw up.
|
|
*/
|
|
fuse_file_put(ff, ff->fc->destroy_req != NULL);
|
|
}
|
|
|
|
static int fuse_open(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_open_common(inode, file, false);
|
|
}
|
|
|
|
static int fuse_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
/* see fuse_vma_close() for !writeback_cache case */
|
|
if (fc->writeback_cache)
|
|
write_inode_now(inode, 1);
|
|
|
|
fuse_release_common(file, FUSE_RELEASE);
|
|
|
|
/* return value is ignored by VFS */
|
|
return 0;
|
|
}
|
|
|
|
void fuse_sync_release(struct fuse_file *ff, int flags)
|
|
{
|
|
WARN_ON(atomic_read(&ff->count) > 1);
|
|
fuse_prepare_release(ff, flags, FUSE_RELEASE);
|
|
__set_bit(FR_FORCE, &ff->reserved_req->flags);
|
|
__clear_bit(FR_BACKGROUND, &ff->reserved_req->flags);
|
|
fuse_request_send(ff->fc, ff->reserved_req);
|
|
fuse_put_request(ff->fc, ff->reserved_req);
|
|
kfree(ff);
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_sync_release);
|
|
|
|
/*
|
|
* 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 any page in a range 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_range_is_writeback(struct inode *inode, pgoff_t idx_from,
|
|
pgoff_t idx_to)
|
|
{
|
|
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_SHIFT;
|
|
if (idx_from < curr_index + req->num_pages &&
|
|
curr_index <= idx_to) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
|
|
return found;
|
|
}
|
|
|
|
static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
|
|
{
|
|
return fuse_range_is_writeback(inode, index, index);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
static int fuse_flush(struct file *file, fl_owner_t id)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
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;
|
|
|
|
err = write_inode_now(inode, 1);
|
|
if (err)
|
|
return err;
|
|
|
|
inode_lock(inode);
|
|
fuse_sync_writes(inode);
|
|
inode_unlock(inode);
|
|
|
|
req = fuse_get_req_nofail_nopages(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;
|
|
__set_bit(FR_FORCE, &req->flags);
|
|
fuse_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;
|
|
}
|
|
|
|
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
|
|
int datasync, int isdir)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
FUSE_ARGS(args);
|
|
struct fuse_fsync_in inarg;
|
|
int err;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
inode_lock(inode);
|
|
|
|
/*
|
|
* Start writeback against all dirty pages of the inode, then
|
|
* wait for all outstanding writes, before sending the FSYNC
|
|
* request.
|
|
*/
|
|
err = filemap_write_and_wait_range(inode->i_mapping, start, end);
|
|
if (err)
|
|
goto out;
|
|
|
|
fuse_sync_writes(inode);
|
|
err = sync_inode_metadata(inode, 1);
|
|
if (err)
|
|
goto out;
|
|
|
|
if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
|
|
goto out;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.fh = ff->fh;
|
|
inarg.fsync_flags = datasync ? 1 : 0;
|
|
args.in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
|
|
args.in.h.nodeid = get_node_id(inode);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err == -ENOSYS) {
|
|
if (isdir)
|
|
fc->no_fsyncdir = 1;
|
|
else
|
|
fc->no_fsync = 1;
|
|
err = 0;
|
|
}
|
|
out:
|
|
inode_unlock(inode);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_fsync(struct file *file, loff_t start, loff_t end,
|
|
int datasync)
|
|
{
|
|
return fuse_fsync_common(file, start, end, datasync, 0);
|
|
}
|
|
|
|
void fuse_read_fill(struct fuse_req *req, struct file *file, 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 = ff->nodeid;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(struct fuse_read_in);
|
|
req->in.args[0].value = inarg;
|
|
req->out.argvar = 1;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = count;
|
|
}
|
|
|
|
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 void fuse_io_release(struct kref *kref)
|
|
{
|
|
kfree(container_of(kref, struct fuse_io_priv, refcnt));
|
|
}
|
|
|
|
static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io)
|
|
{
|
|
if (io->err)
|
|
return io->err;
|
|
|
|
if (io->bytes >= 0 && io->write)
|
|
return -EIO;
|
|
|
|
return io->bytes < 0 ? io->size : io->bytes;
|
|
}
|
|
|
|
/**
|
|
* In case of short read, the caller sets 'pos' to the position of
|
|
* actual end of fuse request in IO request. Otherwise, if bytes_requested
|
|
* == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
|
|
*
|
|
* An example:
|
|
* User requested DIO read of 64K. It was splitted into two 32K fuse requests,
|
|
* both submitted asynchronously. The first of them was ACKed by userspace as
|
|
* fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
|
|
* second request was ACKed as short, e.g. only 1K was read, resulting in
|
|
* pos == 33K.
|
|
*
|
|
* Thus, when all fuse requests are completed, the minimal non-negative 'pos'
|
|
* will be equal to the length of the longest contiguous fragment of
|
|
* transferred data starting from the beginning of IO request.
|
|
*/
|
|
static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
|
|
{
|
|
bool is_sync = is_sync_kiocb(io->iocb);
|
|
int left;
|
|
|
|
spin_lock(&io->lock);
|
|
if (err)
|
|
io->err = io->err ? : err;
|
|
else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
|
|
io->bytes = pos;
|
|
|
|
left = --io->reqs;
|
|
if (!left && is_sync)
|
|
complete(io->done);
|
|
spin_unlock(&io->lock);
|
|
|
|
if (!left && !is_sync) {
|
|
ssize_t res = fuse_get_res_by_io(io);
|
|
|
|
if (res >= 0) {
|
|
struct inode *inode = file_inode(io->iocb->ki_filp);
|
|
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;
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
|
|
io->iocb->ki_complete(io->iocb, res, 0);
|
|
}
|
|
|
|
kref_put(&io->refcnt, fuse_io_release);
|
|
}
|
|
|
|
static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_io_priv *io = req->io;
|
|
ssize_t pos = -1;
|
|
|
|
fuse_release_user_pages(req, !io->write);
|
|
|
|
if (io->write) {
|
|
if (req->misc.write.in.size != req->misc.write.out.size)
|
|
pos = req->misc.write.in.offset - io->offset +
|
|
req->misc.write.out.size;
|
|
} else {
|
|
if (req->misc.read.in.size != req->out.args[0].size)
|
|
pos = req->misc.read.in.offset - io->offset +
|
|
req->out.args[0].size;
|
|
}
|
|
|
|
fuse_aio_complete(io, req->out.h.error, pos);
|
|
}
|
|
|
|
static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
|
|
size_t num_bytes, struct fuse_io_priv *io)
|
|
{
|
|
spin_lock(&io->lock);
|
|
kref_get(&io->refcnt);
|
|
io->size += num_bytes;
|
|
io->reqs++;
|
|
spin_unlock(&io->lock);
|
|
|
|
req->io = io;
|
|
req->end = fuse_aio_complete_req;
|
|
|
|
__fuse_get_request(req);
|
|
fuse_request_send_background(fc, req);
|
|
|
|
return num_bytes;
|
|
}
|
|
|
|
static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
|
|
loff_t pos, size_t count, fl_owner_t owner)
|
|
{
|
|
struct file *file = io->file;
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
|
|
fuse_read_fill(req, file, 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);
|
|
}
|
|
|
|
if (io->async)
|
|
return fuse_async_req_send(fc, req, count, io);
|
|
|
|
fuse_request_send(fc, req);
|
|
return req->out.args[0].size;
|
|
}
|
|
|
|
static void fuse_read_update_size(struct inode *inode, loff_t size,
|
|
u64 attr_ver)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
if (attr_ver == fi->attr_version && size < inode->i_size &&
|
|
!test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
|
|
fi->attr_version = ++fc->attr_version;
|
|
i_size_write(inode, size);
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
|
|
static void fuse_short_read(struct fuse_req *req, struct inode *inode,
|
|
u64 attr_ver)
|
|
{
|
|
size_t num_read = req->out.args[0].size;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (fc->writeback_cache) {
|
|
/*
|
|
* A hole in a file. Some data after the hole are in page cache,
|
|
* but have not reached the client fs yet. So, the hole is not
|
|
* present there.
|
|
*/
|
|
int i;
|
|
int start_idx = num_read >> PAGE_SHIFT;
|
|
size_t off = num_read & (PAGE_SIZE - 1);
|
|
|
|
for (i = start_idx; i < req->num_pages; i++) {
|
|
zero_user_segment(req->pages[i], off, PAGE_SIZE);
|
|
off = 0;
|
|
}
|
|
} else {
|
|
loff_t pos = page_offset(req->pages[0]) + num_read;
|
|
fuse_read_update_size(inode, pos, attr_ver);
|
|
}
|
|
}
|
|
|
|
static int fuse_do_readpage(struct file *file, struct page *page)
|
|
{
|
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);
|
|
struct inode *inode = page->mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
size_t num_read;
|
|
loff_t pos = page_offset(page);
|
|
size_t count = PAGE_SIZE;
|
|
u64 attr_ver;
|
|
int err;
|
|
|
|
/*
|
|
* Page writeback can extend beyond the lifetime 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, 1);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
attr_ver = fuse_get_attr_version(fc);
|
|
|
|
req->out.page_zeroing = 1;
|
|
req->out.argpages = 1;
|
|
req->num_pages = 1;
|
|
req->pages[0] = page;
|
|
req->page_descs[0].length = count;
|
|
num_read = fuse_send_read(req, &io, pos, count, NULL);
|
|
err = req->out.h.error;
|
|
|
|
if (!err) {
|
|
/*
|
|
* Short read means EOF. If file size is larger, truncate it
|
|
*/
|
|
if (num_read < count)
|
|
fuse_short_read(req, inode, attr_ver);
|
|
|
|
SetPageUptodate(page);
|
|
}
|
|
|
|
fuse_put_request(fc, req);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_readpage(struct file *file, struct page *page)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
int err;
|
|
|
|
err = -EIO;
|
|
if (is_bad_inode(inode))
|
|
goto out;
|
|
|
|
err = fuse_do_readpage(file, page);
|
|
fuse_invalidate_atime(inode);
|
|
out:
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
int i;
|
|
size_t count = req->misc.read.in.size;
|
|
size_t num_read = req->out.args[0].size;
|
|
struct address_space *mapping = NULL;
|
|
|
|
for (i = 0; mapping == NULL && i < req->num_pages; i++)
|
|
mapping = req->pages[i]->mapping;
|
|
|
|
if (mapping) {
|
|
struct inode *inode = mapping->host;
|
|
|
|
/*
|
|
* Short read means EOF. If file size is larger, truncate it
|
|
*/
|
|
if (!req->out.h.error && num_read < count)
|
|
fuse_short_read(req, inode, req->misc.read.attr_ver);
|
|
|
|
fuse_invalidate_atime(inode);
|
|
}
|
|
|
|
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);
|
|
put_page(page);
|
|
}
|
|
if (req->ff)
|
|
fuse_file_put(req->ff, false);
|
|
}
|
|
|
|
static void fuse_send_readpages(struct fuse_req *req, struct file *file)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
loff_t pos = page_offset(req->pages[0]);
|
|
size_t count = req->num_pages << PAGE_SHIFT;
|
|
|
|
req->out.argpages = 1;
|
|
req->out.page_zeroing = 1;
|
|
req->out.page_replace = 1;
|
|
fuse_read_fill(req, file, pos, count, FUSE_READ);
|
|
req->misc.read.attr_ver = fuse_get_attr_version(fc);
|
|
if (fc->async_read) {
|
|
req->ff = fuse_file_get(ff);
|
|
req->end = fuse_readpages_end;
|
|
fuse_request_send_background(fc, req);
|
|
} else {
|
|
fuse_request_send(fc, req);
|
|
fuse_readpages_end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
}
|
|
|
|
struct fuse_fill_data {
|
|
struct fuse_req *req;
|
|
struct file *file;
|
|
struct inode *inode;
|
|
unsigned nr_pages;
|
|
};
|
|
|
|
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_SIZE > fc->max_read ||
|
|
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
|
|
int nr_alloc = min_t(unsigned, data->nr_pages,
|
|
FUSE_MAX_PAGES_PER_REQ);
|
|
fuse_send_readpages(req, data->file);
|
|
if (fc->async_read)
|
|
req = fuse_get_req_for_background(fc, nr_alloc);
|
|
else
|
|
req = fuse_get_req(fc, nr_alloc);
|
|
|
|
data->req = req;
|
|
if (IS_ERR(req)) {
|
|
unlock_page(page);
|
|
return PTR_ERR(req);
|
|
}
|
|
}
|
|
|
|
if (WARN_ON(req->num_pages >= req->max_pages)) {
|
|
fuse_put_request(fc, req);
|
|
return -EIO;
|
|
}
|
|
|
|
get_page(page);
|
|
req->pages[req->num_pages] = page;
|
|
req->page_descs[req->num_pages].length = PAGE_SIZE;
|
|
req->num_pages++;
|
|
data->nr_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;
|
|
int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
|
|
|
|
err = -EIO;
|
|
if (is_bad_inode(inode))
|
|
goto out;
|
|
|
|
data.file = file;
|
|
data.inode = inode;
|
|
if (fc->async_read)
|
|
data.req = fuse_get_req_for_background(fc, nr_alloc);
|
|
else
|
|
data.req = fuse_get_req(fc, nr_alloc);
|
|
data.nr_pages = nr_pages;
|
|
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);
|
|
else
|
|
fuse_put_request(fc, data.req);
|
|
}
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
/*
|
|
* In auto invalidate mode, always update attributes on read.
|
|
* Otherwise, only update if we attempt to read past EOF (to ensure
|
|
* i_size is up to date).
|
|
*/
|
|
if (fc->auto_inval_data ||
|
|
(iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) {
|
|
int err;
|
|
err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return generic_file_read_iter(iocb, to);
|
|
}
|
|
|
|
static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
|
|
loff_t pos, size_t count)
|
|
{
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
struct fuse_write_out *outarg = &req->misc.write.out;
|
|
|
|
inarg->fh = ff->fh;
|
|
inarg->offset = pos;
|
|
inarg->size = count;
|
|
req->in.h.opcode = FUSE_WRITE;
|
|
req->in.h.nodeid = ff->nodeid;
|
|
req->in.numargs = 2;
|
|
if (ff->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 fuse_io_priv *io,
|
|
loff_t pos, size_t count, fl_owner_t owner)
|
|
{
|
|
struct file *file = io->file;
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
|
|
fuse_write_fill(req, ff, pos, count);
|
|
inarg->flags = file->f_flags;
|
|
if (owner != NULL) {
|
|
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
|
|
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
|
|
}
|
|
|
|
if (io->async)
|
|
return fuse_async_req_send(fc, req, count, io);
|
|
|
|
fuse_request_send(fc, req);
|
|
return req->misc.write.out.size;
|
|
}
|
|
|
|
bool 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);
|
|
bool ret = false;
|
|
|
|
spin_lock(&fc->lock);
|
|
fi->attr_version = ++fc->attr_version;
|
|
if (pos > inode->i_size) {
|
|
i_size_write(inode, pos);
|
|
ret = true;
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
|
|
struct inode *inode, loff_t pos,
|
|
size_t count)
|
|
{
|
|
size_t res;
|
|
unsigned offset;
|
|
unsigned i;
|
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);
|
|
|
|
for (i = 0; i < req->num_pages; i++)
|
|
fuse_wait_on_page_writeback(inode, req->pages[i]->index);
|
|
|
|
res = fuse_send_write(req, &io, pos, count, NULL);
|
|
|
|
offset = req->page_descs[0].offset;
|
|
count = res;
|
|
for (i = 0; i < req->num_pages; i++) {
|
|
struct page *page = req->pages[i];
|
|
|
|
if (!req->out.h.error && !offset && count >= PAGE_SIZE)
|
|
SetPageUptodate(page);
|
|
|
|
if (count > PAGE_SIZE - offset)
|
|
count -= PAGE_SIZE - offset;
|
|
else
|
|
count = 0;
|
|
offset = 0;
|
|
|
|
unlock_page(page);
|
|
put_page(page);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
static ssize_t fuse_fill_write_pages(struct fuse_req *req,
|
|
struct address_space *mapping,
|
|
struct iov_iter *ii, loff_t pos)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(mapping->host);
|
|
unsigned offset = pos & (PAGE_SIZE - 1);
|
|
size_t count = 0;
|
|
int err;
|
|
|
|
req->in.argpages = 1;
|
|
req->page_descs[0].offset = offset;
|
|
|
|
do {
|
|
size_t tmp;
|
|
struct page *page;
|
|
pgoff_t index = pos >> PAGE_SHIFT;
|
|
size_t bytes = min_t(size_t, PAGE_SIZE - offset,
|
|
iov_iter_count(ii));
|
|
|
|
bytes = min_t(size_t, bytes, fc->max_write - count);
|
|
|
|
again:
|
|
err = -EFAULT;
|
|
if (iov_iter_fault_in_readable(ii, bytes))
|
|
break;
|
|
|
|
err = -ENOMEM;
|
|
page = grab_cache_page_write_begin(mapping, index, 0);
|
|
if (!page)
|
|
break;
|
|
|
|
if (mapping_writably_mapped(mapping))
|
|
flush_dcache_page(page);
|
|
|
|
tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
|
|
flush_dcache_page(page);
|
|
|
|
iov_iter_advance(ii, tmp);
|
|
if (!tmp) {
|
|
unlock_page(page);
|
|
put_page(page);
|
|
bytes = min(bytes, iov_iter_single_seg_count(ii));
|
|
goto again;
|
|
}
|
|
|
|
err = 0;
|
|
req->pages[req->num_pages] = page;
|
|
req->page_descs[req->num_pages].length = tmp;
|
|
req->num_pages++;
|
|
|
|
count += tmp;
|
|
pos += tmp;
|
|
offset += tmp;
|
|
if (offset == PAGE_SIZE)
|
|
offset = 0;
|
|
|
|
if (!fc->big_writes)
|
|
break;
|
|
} while (iov_iter_count(ii) && count < fc->max_write &&
|
|
req->num_pages < req->max_pages && offset == 0);
|
|
|
|
return count > 0 ? count : err;
|
|
}
|
|
|
|
static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
|
|
{
|
|
return min_t(unsigned,
|
|
((pos + len - 1) >> PAGE_SHIFT) -
|
|
(pos >> PAGE_SHIFT) + 1,
|
|
FUSE_MAX_PAGES_PER_REQ);
|
|
}
|
|
|
|
static ssize_t fuse_perform_write(struct file *file,
|
|
struct address_space *mapping,
|
|
struct iov_iter *ii, loff_t pos)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
int err = 0;
|
|
ssize_t res = 0;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
if (inode->i_size < pos + iov_iter_count(ii))
|
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
|
|
do {
|
|
struct fuse_req *req;
|
|
ssize_t count;
|
|
unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
|
|
|
|
req = fuse_get_req(fc, nr_pages);
|
|
if (IS_ERR(req)) {
|
|
err = PTR_ERR(req);
|
|
break;
|
|
}
|
|
|
|
count = fuse_fill_write_pages(req, mapping, ii, pos);
|
|
if (count <= 0) {
|
|
err = count;
|
|
} else {
|
|
size_t num_written;
|
|
|
|
num_written = fuse_send_write_pages(req, file, inode,
|
|
pos, count);
|
|
err = req->out.h.error;
|
|
if (!err) {
|
|
res += num_written;
|
|
pos += num_written;
|
|
|
|
/* break out of the loop on short write */
|
|
if (num_written != count)
|
|
err = -EIO;
|
|
}
|
|
}
|
|
fuse_put_request(fc, req);
|
|
} while (!err && iov_iter_count(ii));
|
|
|
|
if (res > 0)
|
|
fuse_write_update_size(inode, pos);
|
|
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
fuse_invalidate_attr(inode);
|
|
|
|
return res > 0 ? res : err;
|
|
}
|
|
|
|
static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
ssize_t written = 0;
|
|
ssize_t written_buffered = 0;
|
|
struct inode *inode = mapping->host;
|
|
ssize_t err;
|
|
loff_t endbyte = 0;
|
|
|
|
if (get_fuse_conn(inode)->writeback_cache) {
|
|
/* Update size (EOF optimization) and mode (SUID clearing) */
|
|
err = fuse_update_attributes(mapping->host, NULL, file, NULL);
|
|
if (err)
|
|
return err;
|
|
|
|
return generic_file_write_iter(iocb, from);
|
|
}
|
|
|
|
inode_lock(inode);
|
|
|
|
/* We can write back this queue in page reclaim */
|
|
current->backing_dev_info = inode_to_bdi(inode);
|
|
|
|
err = generic_write_checks(iocb, from);
|
|
if (err <= 0)
|
|
goto out;
|
|
|
|
err = file_remove_privs(file);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = file_update_time(file);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (iocb->ki_flags & IOCB_DIRECT) {
|
|
loff_t pos = iocb->ki_pos;
|
|
written = generic_file_direct_write(iocb, from, pos);
|
|
if (written < 0 || !iov_iter_count(from))
|
|
goto out;
|
|
|
|
pos += written;
|
|
|
|
written_buffered = fuse_perform_write(file, mapping, from, pos);
|
|
if (written_buffered < 0) {
|
|
err = written_buffered;
|
|
goto out;
|
|
}
|
|
endbyte = pos + written_buffered - 1;
|
|
|
|
err = filemap_write_and_wait_range(file->f_mapping, pos,
|
|
endbyte);
|
|
if (err)
|
|
goto out;
|
|
|
|
invalidate_mapping_pages(file->f_mapping,
|
|
pos >> PAGE_SHIFT,
|
|
endbyte >> PAGE_SHIFT);
|
|
|
|
written += written_buffered;
|
|
iocb->ki_pos = pos + written_buffered;
|
|
} else {
|
|
written = fuse_perform_write(file, mapping, from, iocb->ki_pos);
|
|
if (written >= 0)
|
|
iocb->ki_pos += written;
|
|
}
|
|
out:
|
|
current->backing_dev_info = NULL;
|
|
inode_unlock(inode);
|
|
|
|
return written ? written : err;
|
|
}
|
|
|
|
static inline void fuse_page_descs_length_init(struct fuse_req *req,
|
|
unsigned index, unsigned nr_pages)
|
|
{
|
|
int i;
|
|
|
|
for (i = index; i < index + nr_pages; i++)
|
|
req->page_descs[i].length = PAGE_SIZE -
|
|
req->page_descs[i].offset;
|
|
}
|
|
|
|
static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
|
|
{
|
|
return (unsigned long)ii->iov->iov_base + ii->iov_offset;
|
|
}
|
|
|
|
static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
|
|
size_t max_size)
|
|
{
|
|
return min(iov_iter_single_seg_count(ii), max_size);
|
|
}
|
|
|
|
static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
|
|
size_t *nbytesp, int write)
|
|
{
|
|
size_t nbytes = 0; /* # bytes already packed in req */
|
|
ssize_t ret = 0;
|
|
|
|
/* Special case for kernel I/O: can copy directly into the buffer */
|
|
if (ii->type & ITER_KVEC) {
|
|
unsigned long user_addr = fuse_get_user_addr(ii);
|
|
size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
|
|
|
|
if (write)
|
|
req->in.args[1].value = (void *) user_addr;
|
|
else
|
|
req->out.args[0].value = (void *) user_addr;
|
|
|
|
iov_iter_advance(ii, frag_size);
|
|
*nbytesp = frag_size;
|
|
return 0;
|
|
}
|
|
|
|
while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
|
|
unsigned npages;
|
|
size_t start;
|
|
ret = iov_iter_get_pages(ii, &req->pages[req->num_pages],
|
|
*nbytesp - nbytes,
|
|
req->max_pages - req->num_pages,
|
|
&start);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
iov_iter_advance(ii, ret);
|
|
nbytes += ret;
|
|
|
|
ret += start;
|
|
npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
|
|
|
|
req->page_descs[req->num_pages].offset = start;
|
|
fuse_page_descs_length_init(req, req->num_pages, npages);
|
|
|
|
req->num_pages += npages;
|
|
req->page_descs[req->num_pages - 1].length -=
|
|
(PAGE_SIZE - ret) & (PAGE_SIZE - 1);
|
|
}
|
|
|
|
if (write)
|
|
req->in.argpages = 1;
|
|
else
|
|
req->out.argpages = 1;
|
|
|
|
*nbytesp = nbytes;
|
|
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
|
|
static inline int fuse_iter_npages(const struct iov_iter *ii_p)
|
|
{
|
|
return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ);
|
|
}
|
|
|
|
ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
|
|
loff_t *ppos, int flags)
|
|
{
|
|
int write = flags & FUSE_DIO_WRITE;
|
|
int cuse = flags & FUSE_DIO_CUSE;
|
|
struct file *file = io->file;
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
size_t nmax = write ? fc->max_write : fc->max_read;
|
|
loff_t pos = *ppos;
|
|
size_t count = iov_iter_count(iter);
|
|
pgoff_t idx_from = pos >> PAGE_SHIFT;
|
|
pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
|
|
ssize_t res = 0;
|
|
struct fuse_req *req;
|
|
int err = 0;
|
|
|
|
if (io->async)
|
|
req = fuse_get_req_for_background(fc, fuse_iter_npages(iter));
|
|
else
|
|
req = fuse_get_req(fc, fuse_iter_npages(iter));
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
|
|
if (!write)
|
|
inode_lock(inode);
|
|
fuse_sync_writes(inode);
|
|
if (!write)
|
|
inode_unlock(inode);
|
|
}
|
|
|
|
while (count) {
|
|
size_t nres;
|
|
fl_owner_t owner = current->files;
|
|
size_t nbytes = min(count, nmax);
|
|
err = fuse_get_user_pages(req, iter, &nbytes, write);
|
|
if (err && !nbytes)
|
|
break;
|
|
|
|
if (write)
|
|
nres = fuse_send_write(req, io, pos, nbytes, owner);
|
|
else
|
|
nres = fuse_send_read(req, io, pos, nbytes, owner);
|
|
|
|
if (!io->async)
|
|
fuse_release_user_pages(req, !write);
|
|
if (req->out.h.error) {
|
|
err = req->out.h.error;
|
|
break;
|
|
} else if (nres > nbytes) {
|
|
res = 0;
|
|
err = -EIO;
|
|
break;
|
|
}
|
|
count -= nres;
|
|
res += nres;
|
|
pos += nres;
|
|
if (nres != nbytes)
|
|
break;
|
|
if (count) {
|
|
fuse_put_request(fc, req);
|
|
if (io->async)
|
|
req = fuse_get_req_for_background(fc,
|
|
fuse_iter_npages(iter));
|
|
else
|
|
req = fuse_get_req(fc, fuse_iter_npages(iter));
|
|
if (IS_ERR(req))
|
|
break;
|
|
}
|
|
}
|
|
if (!IS_ERR(req))
|
|
fuse_put_request(fc, req);
|
|
if (res > 0)
|
|
*ppos = pos;
|
|
|
|
return res > 0 ? res : err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_direct_io);
|
|
|
|
static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
|
|
struct iov_iter *iter,
|
|
loff_t *ppos)
|
|
{
|
|
ssize_t res;
|
|
struct file *file = io->file;
|
|
struct inode *inode = file_inode(file);
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
res = fuse_direct_io(io, iter, ppos, 0);
|
|
|
|
fuse_invalidate_attr(inode);
|
|
|
|
return res;
|
|
}
|
|
|
|
static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
|
{
|
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb->ki_filp);
|
|
return __fuse_direct_read(&io, to, &iocb->ki_pos);
|
|
}
|
|
|
|
static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(file);
|
|
ssize_t res;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
/* Don't allow parallel writes to the same file */
|
|
inode_lock(inode);
|
|
res = generic_write_checks(iocb, from);
|
|
if (res > 0)
|
|
res = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE);
|
|
fuse_invalidate_attr(inode);
|
|
if (res > 0)
|
|
fuse_write_update_size(inode, iocb->ki_pos);
|
|
inode_unlock(inode);
|
|
|
|
return res;
|
|
}
|
|
|
|
static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < req->num_pages; i++)
|
|
__free_page(req->pages[i]);
|
|
|
|
if (req->ff)
|
|
fuse_file_put(req->ff, false);
|
|
}
|
|
|
|
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_to_bdi(inode);
|
|
int i;
|
|
|
|
list_del(&req->writepages_entry);
|
|
for (i = 0; i < req->num_pages; i++) {
|
|
dec_wb_stat(&bdi->wb, WB_WRITEBACK);
|
|
dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
|
|
wb_writeout_inc(&bdi->wb);
|
|
}
|
|
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,
|
|
loff_t size)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
struct fuse_inode *fi = get_fuse_inode(req->inode);
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
__u64 data_size = req->num_pages * PAGE_SIZE;
|
|
|
|
if (!fc->connected)
|
|
goto out_free;
|
|
|
|
if (inarg->offset + data_size <= size) {
|
|
inarg->size = data_size;
|
|
} else if (inarg->offset < size) {
|
|
inarg->size = size - inarg->offset;
|
|
} else {
|
|
/* Got truncated off completely */
|
|
goto out_free;
|
|
}
|
|
|
|
req->in.args[1].size = inarg->size;
|
|
fi->writectr++;
|
|
fuse_request_send_background_locked(fc, req);
|
|
return;
|
|
|
|
out_free:
|
|
fuse_writepage_finish(fc, req);
|
|
spin_unlock(&fc->lock);
|
|
fuse_writepage_free(fc, req);
|
|
fuse_put_request(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)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
size_t crop = i_size_read(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, crop);
|
|
}
|
|
}
|
|
|
|
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);
|
|
while (req->misc.write.next) {
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_write_in *inarg = &req->misc.write.in;
|
|
struct fuse_req *next = req->misc.write.next;
|
|
req->misc.write.next = next->misc.write.next;
|
|
next->misc.write.next = NULL;
|
|
next->ff = fuse_file_get(req->ff);
|
|
list_add(&next->writepages_entry, &fi->writepages);
|
|
|
|
/*
|
|
* Skip fuse_flush_writepages() to make it easy to crop requests
|
|
* based on primary request size.
|
|
*
|
|
* 1st case (trivial): there are no concurrent activities using
|
|
* fuse_set/release_nowrite. Then we're on safe side because
|
|
* fuse_flush_writepages() would call fuse_send_writepage()
|
|
* anyway.
|
|
*
|
|
* 2nd case: someone called fuse_set_nowrite and it is waiting
|
|
* now for completion of all in-flight requests. This happens
|
|
* rarely and no more than once per page, so this should be
|
|
* okay.
|
|
*
|
|
* 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
|
|
* of fuse_set_nowrite..fuse_release_nowrite section. The fact
|
|
* that fuse_set_nowrite returned implies that all in-flight
|
|
* requests were completed along with all of their secondary
|
|
* requests. Further primary requests are blocked by negative
|
|
* writectr. Hence there cannot be any in-flight requests and
|
|
* no invocations of fuse_writepage_end() while we're in
|
|
* fuse_set_nowrite..fuse_release_nowrite section.
|
|
*/
|
|
fuse_send_writepage(fc, next, inarg->offset + inarg->size);
|
|
}
|
|
fi->writectr--;
|
|
fuse_writepage_finish(fc, req);
|
|
spin_unlock(&fc->lock);
|
|
fuse_writepage_free(fc, req);
|
|
}
|
|
|
|
static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc,
|
|
struct fuse_inode *fi)
|
|
{
|
|
struct fuse_file *ff = NULL;
|
|
|
|
spin_lock(&fc->lock);
|
|
if (!list_empty(&fi->write_files)) {
|
|
ff = list_entry(fi->write_files.next, struct fuse_file,
|
|
write_entry);
|
|
fuse_file_get(ff);
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
|
|
return ff;
|
|
}
|
|
|
|
static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc,
|
|
struct fuse_inode *fi)
|
|
{
|
|
struct fuse_file *ff = __fuse_write_file_get(fc, fi);
|
|
WARN_ON(!ff);
|
|
return ff;
|
|
}
|
|
|
|
int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_file *ff;
|
|
int err;
|
|
|
|
ff = __fuse_write_file_get(fc, fi);
|
|
err = fuse_flush_times(inode, ff);
|
|
if (ff)
|
|
fuse_file_put(ff, 0);
|
|
|
|
return err;
|
|
}
|
|
|
|
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 page *tmp_page;
|
|
int error = -ENOMEM;
|
|
|
|
set_page_writeback(page);
|
|
|
|
req = fuse_request_alloc_nofs(1);
|
|
if (!req)
|
|
goto err;
|
|
|
|
/* writeback always goes to bg_queue */
|
|
__set_bit(FR_BACKGROUND, &req->flags);
|
|
tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!tmp_page)
|
|
goto err_free;
|
|
|
|
error = -EIO;
|
|
req->ff = fuse_write_file_get(fc, fi);
|
|
if (!req->ff)
|
|
goto err_nofile;
|
|
|
|
fuse_write_fill(req, req->ff, page_offset(page), 0);
|
|
|
|
copy_highpage(tmp_page, page);
|
|
req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
|
|
req->misc.write.next = NULL;
|
|
req->in.argpages = 1;
|
|
req->num_pages = 1;
|
|
req->pages[0] = tmp_page;
|
|
req->page_descs[0].offset = 0;
|
|
req->page_descs[0].length = PAGE_SIZE;
|
|
req->end = fuse_writepage_end;
|
|
req->inode = inode;
|
|
|
|
inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
|
|
inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
|
|
|
|
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);
|
|
|
|
end_page_writeback(page);
|
|
|
|
return 0;
|
|
|
|
err_nofile:
|
|
__free_page(tmp_page);
|
|
err_free:
|
|
fuse_request_free(req);
|
|
err:
|
|
end_page_writeback(page);
|
|
return error;
|
|
}
|
|
|
|
static int fuse_writepage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
int err;
|
|
|
|
if (fuse_page_is_writeback(page->mapping->host, page->index)) {
|
|
/*
|
|
* ->writepages() should be called for sync() and friends. We
|
|
* should only get here on direct reclaim and then we are
|
|
* allowed to skip a page which is already in flight
|
|
*/
|
|
WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
|
|
|
|
redirty_page_for_writepage(wbc, page);
|
|
return 0;
|
|
}
|
|
|
|
err = fuse_writepage_locked(page);
|
|
unlock_page(page);
|
|
|
|
return err;
|
|
}
|
|
|
|
struct fuse_fill_wb_data {
|
|
struct fuse_req *req;
|
|
struct fuse_file *ff;
|
|
struct inode *inode;
|
|
struct page **orig_pages;
|
|
};
|
|
|
|
static void fuse_writepages_send(struct fuse_fill_wb_data *data)
|
|
{
|
|
struct fuse_req *req = data->req;
|
|
struct inode *inode = data->inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
int num_pages = req->num_pages;
|
|
int i;
|
|
|
|
req->ff = fuse_file_get(data->ff);
|
|
spin_lock(&fc->lock);
|
|
list_add_tail(&req->list, &fi->queued_writes);
|
|
fuse_flush_writepages(inode);
|
|
spin_unlock(&fc->lock);
|
|
|
|
for (i = 0; i < num_pages; i++)
|
|
end_page_writeback(data->orig_pages[i]);
|
|
}
|
|
|
|
static bool fuse_writepage_in_flight(struct fuse_req *new_req,
|
|
struct page *page)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(new_req->inode);
|
|
struct fuse_inode *fi = get_fuse_inode(new_req->inode);
|
|
struct fuse_req *tmp;
|
|
struct fuse_req *old_req;
|
|
bool found = false;
|
|
pgoff_t curr_index;
|
|
|
|
BUG_ON(new_req->num_pages != 0);
|
|
|
|
spin_lock(&fc->lock);
|
|
list_del(&new_req->writepages_entry);
|
|
list_for_each_entry(old_req, &fi->writepages, writepages_entry) {
|
|
BUG_ON(old_req->inode != new_req->inode);
|
|
curr_index = old_req->misc.write.in.offset >> PAGE_SHIFT;
|
|
if (curr_index <= page->index &&
|
|
page->index < curr_index + old_req->num_pages) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
list_add(&new_req->writepages_entry, &fi->writepages);
|
|
goto out_unlock;
|
|
}
|
|
|
|
new_req->num_pages = 1;
|
|
for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) {
|
|
BUG_ON(tmp->inode != new_req->inode);
|
|
curr_index = tmp->misc.write.in.offset >> PAGE_SHIFT;
|
|
if (tmp->num_pages == 1 &&
|
|
curr_index == page->index) {
|
|
old_req = tmp;
|
|
}
|
|
}
|
|
|
|
if (old_req->num_pages == 1 && test_bit(FR_PENDING, &old_req->flags)) {
|
|
struct backing_dev_info *bdi = inode_to_bdi(page->mapping->host);
|
|
|
|
copy_highpage(old_req->pages[0], page);
|
|
spin_unlock(&fc->lock);
|
|
|
|
dec_wb_stat(&bdi->wb, WB_WRITEBACK);
|
|
dec_zone_page_state(page, NR_WRITEBACK_TEMP);
|
|
wb_writeout_inc(&bdi->wb);
|
|
fuse_writepage_free(fc, new_req);
|
|
fuse_request_free(new_req);
|
|
goto out;
|
|
} else {
|
|
new_req->misc.write.next = old_req->misc.write.next;
|
|
old_req->misc.write.next = new_req;
|
|
}
|
|
out_unlock:
|
|
spin_unlock(&fc->lock);
|
|
out:
|
|
return found;
|
|
}
|
|
|
|
static int fuse_writepages_fill(struct page *page,
|
|
struct writeback_control *wbc, void *_data)
|
|
{
|
|
struct fuse_fill_wb_data *data = _data;
|
|
struct fuse_req *req = data->req;
|
|
struct inode *inode = data->inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct page *tmp_page;
|
|
bool is_writeback;
|
|
int err;
|
|
|
|
if (!data->ff) {
|
|
err = -EIO;
|
|
data->ff = fuse_write_file_get(fc, get_fuse_inode(inode));
|
|
if (!data->ff)
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Being under writeback is unlikely but possible. For example direct
|
|
* read to an mmaped fuse file will set the page dirty twice; once when
|
|
* the pages are faulted with get_user_pages(), and then after the read
|
|
* completed.
|
|
*/
|
|
is_writeback = fuse_page_is_writeback(inode, page->index);
|
|
|
|
if (req && req->num_pages &&
|
|
(is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
|
|
(req->num_pages + 1) * PAGE_SIZE > fc->max_write ||
|
|
data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
|
|
fuse_writepages_send(data);
|
|
data->req = NULL;
|
|
}
|
|
err = -ENOMEM;
|
|
tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!tmp_page)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* The page must not be redirtied until the writeout is completed
|
|
* (i.e. userspace has sent a reply to the write request). Otherwise
|
|
* there could be more than one temporary page instance for each real
|
|
* page.
|
|
*
|
|
* This is ensured by holding the page lock in page_mkwrite() while
|
|
* checking fuse_page_is_writeback(). We already hold the page lock
|
|
* since clear_page_dirty_for_io() and keep it held until we add the
|
|
* request to the fi->writepages list and increment req->num_pages.
|
|
* After this fuse_page_is_writeback() will indicate that the page is
|
|
* under writeback, so we can release the page lock.
|
|
*/
|
|
if (data->req == NULL) {
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
err = -ENOMEM;
|
|
req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ);
|
|
if (!req) {
|
|
__free_page(tmp_page);
|
|
goto out_unlock;
|
|
}
|
|
|
|
fuse_write_fill(req, data->ff, page_offset(page), 0);
|
|
req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
|
|
req->misc.write.next = NULL;
|
|
req->in.argpages = 1;
|
|
__set_bit(FR_BACKGROUND, &req->flags);
|
|
req->num_pages = 0;
|
|
req->end = fuse_writepage_end;
|
|
req->inode = inode;
|
|
|
|
spin_lock(&fc->lock);
|
|
list_add(&req->writepages_entry, &fi->writepages);
|
|
spin_unlock(&fc->lock);
|
|
|
|
data->req = req;
|
|
}
|
|
set_page_writeback(page);
|
|
|
|
copy_highpage(tmp_page, page);
|
|
req->pages[req->num_pages] = tmp_page;
|
|
req->page_descs[req->num_pages].offset = 0;
|
|
req->page_descs[req->num_pages].length = PAGE_SIZE;
|
|
|
|
inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
|
|
inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
|
|
|
|
err = 0;
|
|
if (is_writeback && fuse_writepage_in_flight(req, page)) {
|
|
end_page_writeback(page);
|
|
data->req = NULL;
|
|
goto out_unlock;
|
|
}
|
|
data->orig_pages[req->num_pages] = page;
|
|
|
|
/*
|
|
* Protected by fc->lock against concurrent access by
|
|
* fuse_page_is_writeback().
|
|
*/
|
|
spin_lock(&fc->lock);
|
|
req->num_pages++;
|
|
spin_unlock(&fc->lock);
|
|
|
|
out_unlock:
|
|
unlock_page(page);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_writepages(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct fuse_fill_wb_data data;
|
|
int err;
|
|
|
|
err = -EIO;
|
|
if (is_bad_inode(inode))
|
|
goto out;
|
|
|
|
data.inode = inode;
|
|
data.req = NULL;
|
|
data.ff = NULL;
|
|
|
|
err = -ENOMEM;
|
|
data.orig_pages = kcalloc(FUSE_MAX_PAGES_PER_REQ,
|
|
sizeof(struct page *),
|
|
GFP_NOFS);
|
|
if (!data.orig_pages)
|
|
goto out;
|
|
|
|
err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
|
|
if (data.req) {
|
|
/* Ignore errors if we can write at least one page */
|
|
BUG_ON(!data.req->num_pages);
|
|
fuse_writepages_send(&data);
|
|
err = 0;
|
|
}
|
|
if (data.ff)
|
|
fuse_file_put(data.ff, false);
|
|
|
|
kfree(data.orig_pages);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* It's worthy to make sure that space is reserved on disk for the write,
|
|
* but how to implement it without killing performance need more thinking.
|
|
*/
|
|
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_SHIFT;
|
|
struct fuse_conn *fc = get_fuse_conn(file_inode(file));
|
|
struct page *page;
|
|
loff_t fsize;
|
|
int err = -ENOMEM;
|
|
|
|
WARN_ON(!fc->writeback_cache);
|
|
|
|
page = grab_cache_page_write_begin(mapping, index, flags);
|
|
if (!page)
|
|
goto error;
|
|
|
|
fuse_wait_on_page_writeback(mapping->host, page->index);
|
|
|
|
if (PageUptodate(page) || len == PAGE_SIZE)
|
|
goto success;
|
|
/*
|
|
* Check if the start this page comes after the end of file, in which
|
|
* case the readpage can be optimized away.
|
|
*/
|
|
fsize = i_size_read(mapping->host);
|
|
if (fsize <= (pos & PAGE_MASK)) {
|
|
size_t off = pos & ~PAGE_MASK;
|
|
if (off)
|
|
zero_user_segment(page, 0, off);
|
|
goto success;
|
|
}
|
|
err = fuse_do_readpage(file, page);
|
|
if (err)
|
|
goto cleanup;
|
|
success:
|
|
*pagep = page;
|
|
return 0;
|
|
|
|
cleanup:
|
|
unlock_page(page);
|
|
put_page(page);
|
|
error:
|
|
return err;
|
|
}
|
|
|
|
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 = page->mapping->host;
|
|
|
|
if (!PageUptodate(page)) {
|
|
/* Zero any unwritten bytes at the end of the page */
|
|
size_t endoff = (pos + copied) & ~PAGE_MASK;
|
|
if (endoff)
|
|
zero_user_segment(page, endoff, PAGE_SIZE);
|
|
SetPageUptodate(page);
|
|
}
|
|
|
|
fuse_write_update_size(inode, pos + copied);
|
|
set_page_dirty(page);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
|
|
return copied;
|
|
}
|
|
|
|
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 vm_fault *vmf)
|
|
{
|
|
struct page *page = vmf->page;
|
|
struct inode *inode = file_inode(vma->vm_file);
|
|
|
|
file_update_time(vma->vm_file);
|
|
lock_page(page);
|
|
if (page->mapping != inode->i_mapping) {
|
|
unlock_page(page);
|
|
return VM_FAULT_NOPAGE;
|
|
}
|
|
|
|
fuse_wait_on_page_writeback(inode, page->index);
|
|
return VM_FAULT_LOCKED;
|
|
}
|
|
|
|
static const struct vm_operations_struct fuse_file_vm_ops = {
|
|
.close = fuse_vma_close,
|
|
.fault = filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.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))
|
|
fuse_link_write_file(file);
|
|
|
|
file_accessed(file);
|
|
vma->vm_ops = &fuse_file_vm_ops;
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
/* Can't provide the coherency needed for MAP_SHARED */
|
|
if (vma->vm_flags & VM_MAYSHARE)
|
|
return -ENODEV;
|
|
|
|
invalidate_inode_pages2(file->f_mapping);
|
|
|
|
return generic_file_mmap(file, vma);
|
|
}
|
|
|
|
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_args *args, struct file *file,
|
|
const struct file_lock *fl, int opcode, pid_t pid,
|
|
int flock, struct fuse_lk_in *inarg)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
|
|
memset(inarg, 0, sizeof(*inarg));
|
|
inarg->fh = ff->fh;
|
|
inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
|
|
inarg->lk.start = fl->fl_start;
|
|
inarg->lk.end = fl->fl_end;
|
|
inarg->lk.type = fl->fl_type;
|
|
inarg->lk.pid = pid;
|
|
if (flock)
|
|
inarg->lk_flags |= FUSE_LK_FLOCK;
|
|
args->in.h.opcode = opcode;
|
|
args->in.h.nodeid = get_node_id(inode);
|
|
args->in.numargs = 1;
|
|
args->in.args[0].size = sizeof(*inarg);
|
|
args->in.args[0].value = inarg;
|
|
}
|
|
|
|
static int fuse_getlk(struct file *file, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
struct fuse_lk_in inarg;
|
|
struct fuse_lk_out outarg;
|
|
int err;
|
|
|
|
fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg);
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(outarg);
|
|
args.out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
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_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
struct fuse_lk_in inarg;
|
|
int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
|
|
pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
|
|
int err;
|
|
|
|
if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
|
|
/* NLM needs asynchronous locks, which we don't support yet */
|
|
return -ENOLCK;
|
|
}
|
|
|
|
/* Unlock on close is handled by the flush method */
|
|
if (fl->fl_flags & FL_CLOSE)
|
|
return 0;
|
|
|
|
fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg);
|
|
err = fuse_simple_request(fc, &args);
|
|
|
|
/* locking is restartable */
|
|
if (err == -EINTR)
|
|
err = -ERESTARTSYS;
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int err;
|
|
|
|
if (cmd == F_CANCELLK) {
|
|
err = 0;
|
|
} else 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(file, fl, NULL);
|
|
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_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int err;
|
|
|
|
if (fc->no_flock) {
|
|
err = locks_lock_file_wait(file, fl);
|
|
} else {
|
|
struct fuse_file *ff = file->private_data;
|
|
|
|
/* emulate flock with POSIX locks */
|
|
ff->flock = true;
|
|
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);
|
|
FUSE_ARGS(args);
|
|
struct fuse_bmap_in inarg;
|
|
struct fuse_bmap_out outarg;
|
|
int err;
|
|
|
|
if (!inode->i_sb->s_bdev || fc->no_bmap)
|
|
return 0;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.block = block;
|
|
inarg.blocksize = inode->i_sb->s_blocksize;
|
|
args.in.h.opcode = FUSE_BMAP;
|
|
args.in.h.nodeid = get_node_id(inode);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(outarg);
|
|
args.out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err == -ENOSYS)
|
|
fc->no_bmap = 1;
|
|
|
|
return err ? 0 : outarg.block;
|
|
}
|
|
|
|
static loff_t fuse_lseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_file *ff = file->private_data;
|
|
FUSE_ARGS(args);
|
|
struct fuse_lseek_in inarg = {
|
|
.fh = ff->fh,
|
|
.offset = offset,
|
|
.whence = whence
|
|
};
|
|
struct fuse_lseek_out outarg;
|
|
int err;
|
|
|
|
if (fc->no_lseek)
|
|
goto fallback;
|
|
|
|
args.in.h.opcode = FUSE_LSEEK;
|
|
args.in.h.nodeid = ff->nodeid;
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(outarg);
|
|
args.out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err) {
|
|
if (err == -ENOSYS) {
|
|
fc->no_lseek = 1;
|
|
goto fallback;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes);
|
|
|
|
fallback:
|
|
err = fuse_update_attributes(inode, NULL, file, NULL);
|
|
if (!err)
|
|
return generic_file_llseek(file, offset, whence);
|
|
else
|
|
return err;
|
|
}
|
|
|
|
static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
loff_t retval;
|
|
struct inode *inode = file_inode(file);
|
|
|
|
switch (whence) {
|
|
case SEEK_SET:
|
|
case SEEK_CUR:
|
|
/* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
|
|
retval = generic_file_llseek(file, offset, whence);
|
|
break;
|
|
case SEEK_END:
|
|
inode_lock(inode);
|
|
retval = fuse_update_attributes(inode, NULL, file, NULL);
|
|
if (!retval)
|
|
retval = generic_file_llseek(file, offset, whence);
|
|
inode_unlock(inode);
|
|
break;
|
|
case SEEK_HOLE:
|
|
case SEEK_DATA:
|
|
inode_lock(inode);
|
|
retval = fuse_lseek(file, offset, whence);
|
|
inode_unlock(inode);
|
|
break;
|
|
default:
|
|
retval = -EINVAL;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
|
|
unsigned int nr_segs, size_t bytes, bool to_user)
|
|
{
|
|
struct iov_iter ii;
|
|
int page_idx = 0;
|
|
|
|
if (!bytes)
|
|
return 0;
|
|
|
|
iov_iter_init(&ii, to_user ? READ : WRITE, iov, nr_segs, bytes);
|
|
|
|
while (iov_iter_count(&ii)) {
|
|
struct page *page = pages[page_idx++];
|
|
size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
|
|
void *kaddr;
|
|
|
|
kaddr = kmap(page);
|
|
|
|
while (todo) {
|
|
char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
|
|
size_t iov_len = ii.iov->iov_len - ii.iov_offset;
|
|
size_t copy = min(todo, iov_len);
|
|
size_t left;
|
|
|
|
if (!to_user)
|
|
left = copy_from_user(kaddr, uaddr, copy);
|
|
else
|
|
left = copy_to_user(uaddr, kaddr, copy);
|
|
|
|
if (unlikely(left))
|
|
return -EFAULT;
|
|
|
|
iov_iter_advance(&ii, copy);
|
|
todo -= copy;
|
|
kaddr += copy;
|
|
}
|
|
|
|
kunmap(page);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* CUSE servers compiled on 32bit broke on 64bit kernels because the
|
|
* ABI was defined to be 'struct iovec' which is different on 32bit
|
|
* and 64bit. Fortunately we can determine which structure the server
|
|
* used from the size of the reply.
|
|
*/
|
|
static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
|
|
size_t transferred, unsigned count,
|
|
bool is_compat)
|
|
{
|
|
#ifdef CONFIG_COMPAT
|
|
if (count * sizeof(struct compat_iovec) == transferred) {
|
|
struct compat_iovec *ciov = src;
|
|
unsigned i;
|
|
|
|
/*
|
|
* With this interface a 32bit server cannot support
|
|
* non-compat (i.e. ones coming from 64bit apps) ioctl
|
|
* requests
|
|
*/
|
|
if (!is_compat)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
dst[i].iov_base = compat_ptr(ciov[i].iov_base);
|
|
dst[i].iov_len = ciov[i].iov_len;
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
if (count * sizeof(struct iovec) != transferred)
|
|
return -EIO;
|
|
|
|
memcpy(dst, src, transferred);
|
|
return 0;
|
|
}
|
|
|
|
/* Make sure iov_length() won't overflow */
|
|
static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
|
|
{
|
|
size_t n;
|
|
u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
|
|
|
|
for (n = 0; n < count; n++, iov++) {
|
|
if (iov->iov_len > (size_t) max)
|
|
return -ENOMEM;
|
|
max -= iov->iov_len;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
|
|
void *src, size_t transferred, unsigned count,
|
|
bool is_compat)
|
|
{
|
|
unsigned i;
|
|
struct fuse_ioctl_iovec *fiov = src;
|
|
|
|
if (fc->minor < 16) {
|
|
return fuse_copy_ioctl_iovec_old(dst, src, transferred,
|
|
count, is_compat);
|
|
}
|
|
|
|
if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
|
|
return -EIO;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
/* Did the server supply an inappropriate value? */
|
|
if (fiov[i].base != (unsigned long) fiov[i].base ||
|
|
fiov[i].len != (unsigned long) fiov[i].len)
|
|
return -EIO;
|
|
|
|
dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
|
|
dst[i].iov_len = (size_t) fiov[i].len;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (is_compat &&
|
|
(ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
|
|
(compat_size_t) dst[i].iov_len != fiov[i].len))
|
|
return -EIO;
|
|
#endif
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* For ioctls, there is no generic way to determine how much memory
|
|
* needs to be read and/or written. Furthermore, ioctls are allowed
|
|
* to dereference the passed pointer, so the parameter requires deep
|
|
* copying but FUSE has no idea whatsoever about what to copy in or
|
|
* out.
|
|
*
|
|
* This is solved by allowing FUSE server to retry ioctl with
|
|
* necessary in/out iovecs. Let's assume the ioctl implementation
|
|
* needs to read in the following structure.
|
|
*
|
|
* struct a {
|
|
* char *buf;
|
|
* size_t buflen;
|
|
* }
|
|
*
|
|
* On the first callout to FUSE server, inarg->in_size and
|
|
* inarg->out_size will be NULL; then, the server completes the ioctl
|
|
* with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
|
|
* the actual iov array to
|
|
*
|
|
* { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
|
|
*
|
|
* which tells FUSE to copy in the requested area and retry the ioctl.
|
|
* On the second round, the server has access to the structure and
|
|
* from that it can tell what to look for next, so on the invocation,
|
|
* it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
|
|
*
|
|
* { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
|
|
* { .iov_base = a.buf, .iov_len = a.buflen } }
|
|
*
|
|
* FUSE will copy both struct a and the pointed buffer from the
|
|
* process doing the ioctl and retry ioctl with both struct a and the
|
|
* buffer.
|
|
*
|
|
* This time, FUSE server has everything it needs and completes ioctl
|
|
* without FUSE_IOCTL_RETRY which finishes the ioctl call.
|
|
*
|
|
* Copying data out works the same way.
|
|
*
|
|
* Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
|
|
* automatically initializes in and out iovs by decoding @cmd with
|
|
* _IOC_* macros and the server is not allowed to request RETRY. This
|
|
* limits ioctl data transfers to well-formed ioctls and is the forced
|
|
* behavior for all FUSE servers.
|
|
*/
|
|
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
|
|
unsigned int flags)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
struct fuse_ioctl_in inarg = {
|
|
.fh = ff->fh,
|
|
.cmd = cmd,
|
|
.arg = arg,
|
|
.flags = flags
|
|
};
|
|
struct fuse_ioctl_out outarg;
|
|
struct fuse_req *req = NULL;
|
|
struct page **pages = NULL;
|
|
struct iovec *iov_page = NULL;
|
|
struct iovec *in_iov = NULL, *out_iov = NULL;
|
|
unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
|
|
size_t in_size, out_size, transferred;
|
|
int err;
|
|
|
|
#if BITS_PER_LONG == 32
|
|
inarg.flags |= FUSE_IOCTL_32BIT;
|
|
#else
|
|
if (flags & FUSE_IOCTL_COMPAT)
|
|
inarg.flags |= FUSE_IOCTL_32BIT;
|
|
#endif
|
|
|
|
/* assume all the iovs returned by client always fits in a page */
|
|
BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
|
|
|
|
err = -ENOMEM;
|
|
pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
|
|
iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
|
|
if (!pages || !iov_page)
|
|
goto out;
|
|
|
|
/*
|
|
* If restricted, initialize IO parameters as encoded in @cmd.
|
|
* RETRY from server is not allowed.
|
|
*/
|
|
if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
|
|
struct iovec *iov = iov_page;
|
|
|
|
iov->iov_base = (void __user *)arg;
|
|
iov->iov_len = _IOC_SIZE(cmd);
|
|
|
|
if (_IOC_DIR(cmd) & _IOC_WRITE) {
|
|
in_iov = iov;
|
|
in_iovs = 1;
|
|
}
|
|
|
|
if (_IOC_DIR(cmd) & _IOC_READ) {
|
|
out_iov = iov;
|
|
out_iovs = 1;
|
|
}
|
|
}
|
|
|
|
retry:
|
|
inarg.in_size = in_size = iov_length(in_iov, in_iovs);
|
|
inarg.out_size = out_size = iov_length(out_iov, out_iovs);
|
|
|
|
/*
|
|
* Out data can be used either for actual out data or iovs,
|
|
* make sure there always is at least one page.
|
|
*/
|
|
out_size = max_t(size_t, out_size, PAGE_SIZE);
|
|
max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
|
|
|
|
/* make sure there are enough buffer pages and init request with them */
|
|
err = -ENOMEM;
|
|
if (max_pages > FUSE_MAX_PAGES_PER_REQ)
|
|
goto out;
|
|
while (num_pages < max_pages) {
|
|
pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
|
|
if (!pages[num_pages])
|
|
goto out;
|
|
num_pages++;
|
|
}
|
|
|
|
req = fuse_get_req(fc, num_pages);
|
|
if (IS_ERR(req)) {
|
|
err = PTR_ERR(req);
|
|
req = NULL;
|
|
goto out;
|
|
}
|
|
memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
|
|
req->num_pages = num_pages;
|
|
fuse_page_descs_length_init(req, 0, req->num_pages);
|
|
|
|
/* okay, let's send it to the client */
|
|
req->in.h.opcode = FUSE_IOCTL;
|
|
req->in.h.nodeid = ff->nodeid;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
if (in_size) {
|
|
req->in.numargs++;
|
|
req->in.args[1].size = in_size;
|
|
req->in.argpages = 1;
|
|
|
|
err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
|
|
false);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
req->out.numargs = 2;
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
req->out.args[1].size = out_size;
|
|
req->out.argpages = 1;
|
|
req->out.argvar = 1;
|
|
|
|
fuse_request_send(fc, req);
|
|
err = req->out.h.error;
|
|
transferred = req->out.args[1].size;
|
|
fuse_put_request(fc, req);
|
|
req = NULL;
|
|
if (err)
|
|
goto out;
|
|
|
|
/* did it ask for retry? */
|
|
if (outarg.flags & FUSE_IOCTL_RETRY) {
|
|
void *vaddr;
|
|
|
|
/* no retry if in restricted mode */
|
|
err = -EIO;
|
|
if (!(flags & FUSE_IOCTL_UNRESTRICTED))
|
|
goto out;
|
|
|
|
in_iovs = outarg.in_iovs;
|
|
out_iovs = outarg.out_iovs;
|
|
|
|
/*
|
|
* Make sure things are in boundary, separate checks
|
|
* are to protect against overflow.
|
|
*/
|
|
err = -ENOMEM;
|
|
if (in_iovs > FUSE_IOCTL_MAX_IOV ||
|
|
out_iovs > FUSE_IOCTL_MAX_IOV ||
|
|
in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
|
|
goto out;
|
|
|
|
vaddr = kmap_atomic(pages[0]);
|
|
err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
|
|
transferred, in_iovs + out_iovs,
|
|
(flags & FUSE_IOCTL_COMPAT) != 0);
|
|
kunmap_atomic(vaddr);
|
|
if (err)
|
|
goto out;
|
|
|
|
in_iov = iov_page;
|
|
out_iov = in_iov + in_iovs;
|
|
|
|
err = fuse_verify_ioctl_iov(in_iov, in_iovs);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = fuse_verify_ioctl_iov(out_iov, out_iovs);
|
|
if (err)
|
|
goto out;
|
|
|
|
goto retry;
|
|
}
|
|
|
|
err = -EIO;
|
|
if (transferred > inarg.out_size)
|
|
goto out;
|
|
|
|
err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
|
|
out:
|
|
if (req)
|
|
fuse_put_request(fc, req);
|
|
free_page((unsigned long) iov_page);
|
|
while (num_pages)
|
|
__free_page(pages[--num_pages]);
|
|
kfree(pages);
|
|
|
|
return err ? err : outarg.result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_do_ioctl);
|
|
|
|
long fuse_ioctl_common(struct file *file, unsigned int cmd,
|
|
unsigned long arg, unsigned int flags)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (!fuse_allow_current_process(fc))
|
|
return -EACCES;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
return fuse_do_ioctl(file, cmd, arg, flags);
|
|
}
|
|
|
|
static long fuse_file_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return fuse_ioctl_common(file, cmd, arg, 0);
|
|
}
|
|
|
|
static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
|
|
}
|
|
|
|
/*
|
|
* All files which have been polled are linked to RB tree
|
|
* fuse_conn->polled_files which is indexed by kh. Walk the tree and
|
|
* find the matching one.
|
|
*/
|
|
static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
|
|
struct rb_node **parent_out)
|
|
{
|
|
struct rb_node **link = &fc->polled_files.rb_node;
|
|
struct rb_node *last = NULL;
|
|
|
|
while (*link) {
|
|
struct fuse_file *ff;
|
|
|
|
last = *link;
|
|
ff = rb_entry(last, struct fuse_file, polled_node);
|
|
|
|
if (kh < ff->kh)
|
|
link = &last->rb_left;
|
|
else if (kh > ff->kh)
|
|
link = &last->rb_right;
|
|
else
|
|
return link;
|
|
}
|
|
|
|
if (parent_out)
|
|
*parent_out = last;
|
|
return link;
|
|
}
|
|
|
|
/*
|
|
* The file is about to be polled. Make sure it's on the polled_files
|
|
* RB tree. Note that files once added to the polled_files tree are
|
|
* not removed before the file is released. This is because a file
|
|
* polled once is likely to be polled again.
|
|
*/
|
|
static void fuse_register_polled_file(struct fuse_conn *fc,
|
|
struct fuse_file *ff)
|
|
{
|
|
spin_lock(&fc->lock);
|
|
if (RB_EMPTY_NODE(&ff->polled_node)) {
|
|
struct rb_node **link, *uninitialized_var(parent);
|
|
|
|
link = fuse_find_polled_node(fc, ff->kh, &parent);
|
|
BUG_ON(*link);
|
|
rb_link_node(&ff->polled_node, parent, link);
|
|
rb_insert_color(&ff->polled_node, &fc->polled_files);
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
|
|
unsigned fuse_file_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
struct fuse_conn *fc = ff->fc;
|
|
struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
|
|
struct fuse_poll_out outarg;
|
|
FUSE_ARGS(args);
|
|
int err;
|
|
|
|
if (fc->no_poll)
|
|
return DEFAULT_POLLMASK;
|
|
|
|
poll_wait(file, &ff->poll_wait, wait);
|
|
inarg.events = (__u32)poll_requested_events(wait);
|
|
|
|
/*
|
|
* Ask for notification iff there's someone waiting for it.
|
|
* The client may ignore the flag and always notify.
|
|
*/
|
|
if (waitqueue_active(&ff->poll_wait)) {
|
|
inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
|
|
fuse_register_polled_file(fc, ff);
|
|
}
|
|
|
|
args.in.h.opcode = FUSE_POLL;
|
|
args.in.h.nodeid = ff->nodeid;
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(outarg);
|
|
args.out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
|
|
if (!err)
|
|
return outarg.revents;
|
|
if (err == -ENOSYS) {
|
|
fc->no_poll = 1;
|
|
return DEFAULT_POLLMASK;
|
|
}
|
|
return POLLERR;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_file_poll);
|
|
|
|
/*
|
|
* This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
|
|
* wakes up the poll waiters.
|
|
*/
|
|
int fuse_notify_poll_wakeup(struct fuse_conn *fc,
|
|
struct fuse_notify_poll_wakeup_out *outarg)
|
|
{
|
|
u64 kh = outarg->kh;
|
|
struct rb_node **link;
|
|
|
|
spin_lock(&fc->lock);
|
|
|
|
link = fuse_find_polled_node(fc, kh, NULL);
|
|
if (*link) {
|
|
struct fuse_file *ff;
|
|
|
|
ff = rb_entry(*link, struct fuse_file, polled_node);
|
|
wake_up_interruptible_sync(&ff->poll_wait);
|
|
}
|
|
|
|
spin_unlock(&fc->lock);
|
|
return 0;
|
|
}
|
|
|
|
static void fuse_do_truncate(struct file *file)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct iattr attr;
|
|
|
|
attr.ia_valid = ATTR_SIZE;
|
|
attr.ia_size = i_size_read(inode);
|
|
|
|
attr.ia_file = file;
|
|
attr.ia_valid |= ATTR_FILE;
|
|
|
|
fuse_do_setattr(inode, &attr, file);
|
|
}
|
|
|
|
static inline loff_t fuse_round_up(loff_t off)
|
|
{
|
|
return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
|
|
}
|
|
|
|
static ssize_t
|
|
fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK(wait);
|
|
ssize_t ret = 0;
|
|
struct file *file = iocb->ki_filp;
|
|
struct fuse_file *ff = file->private_data;
|
|
bool async_dio = ff->fc->async_dio;
|
|
loff_t pos = 0;
|
|
struct inode *inode;
|
|
loff_t i_size;
|
|
size_t count = iov_iter_count(iter);
|
|
struct fuse_io_priv *io;
|
|
bool is_sync = is_sync_kiocb(iocb);
|
|
|
|
pos = offset;
|
|
inode = file->f_mapping->host;
|
|
i_size = i_size_read(inode);
|
|
|
|
if ((iov_iter_rw(iter) == READ) && (offset > i_size))
|
|
return 0;
|
|
|
|
/* optimization for short read */
|
|
if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) {
|
|
if (offset >= i_size)
|
|
return 0;
|
|
iov_iter_truncate(iter, fuse_round_up(i_size - offset));
|
|
count = iov_iter_count(iter);
|
|
}
|
|
|
|
io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
|
|
if (!io)
|
|
return -ENOMEM;
|
|
spin_lock_init(&io->lock);
|
|
kref_init(&io->refcnt);
|
|
io->reqs = 1;
|
|
io->bytes = -1;
|
|
io->size = 0;
|
|
io->offset = offset;
|
|
io->write = (iov_iter_rw(iter) == WRITE);
|
|
io->err = 0;
|
|
io->file = file;
|
|
/*
|
|
* By default, we want to optimize all I/Os with async request
|
|
* submission to the client filesystem if supported.
|
|
*/
|
|
io->async = async_dio;
|
|
io->iocb = iocb;
|
|
|
|
/*
|
|
* We cannot asynchronously extend the size of a file. We have no method
|
|
* to wait on real async I/O requests, so we must submit this request
|
|
* synchronously.
|
|
*/
|
|
if (!is_sync && (offset + count > i_size) &&
|
|
iov_iter_rw(iter) == WRITE)
|
|
io->async = false;
|
|
|
|
if (io->async && is_sync) {
|
|
/*
|
|
* Additional reference to keep io around after
|
|
* calling fuse_aio_complete()
|
|
*/
|
|
kref_get(&io->refcnt);
|
|
io->done = &wait;
|
|
}
|
|
|
|
if (iov_iter_rw(iter) == WRITE) {
|
|
ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE);
|
|
fuse_invalidate_attr(inode);
|
|
} else {
|
|
ret = __fuse_direct_read(io, iter, &pos);
|
|
}
|
|
|
|
if (io->async) {
|
|
fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
|
|
|
|
/* we have a non-extending, async request, so return */
|
|
if (!is_sync)
|
|
return -EIOCBQUEUED;
|
|
|
|
wait_for_completion(&wait);
|
|
ret = fuse_get_res_by_io(io);
|
|
}
|
|
|
|
kref_put(&io->refcnt, fuse_io_release);
|
|
|
|
if (iov_iter_rw(iter) == WRITE) {
|
|
if (ret > 0)
|
|
fuse_write_update_size(inode, pos);
|
|
else if (ret < 0 && offset + count > i_size)
|
|
fuse_do_truncate(file);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
|
|
loff_t length)
|
|
{
|
|
struct fuse_file *ff = file->private_data;
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_conn *fc = ff->fc;
|
|
FUSE_ARGS(args);
|
|
struct fuse_fallocate_in inarg = {
|
|
.fh = ff->fh,
|
|
.offset = offset,
|
|
.length = length,
|
|
.mode = mode
|
|
};
|
|
int err;
|
|
bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
|
|
(mode & FALLOC_FL_PUNCH_HOLE);
|
|
|
|
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (fc->no_fallocate)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (lock_inode) {
|
|
inode_lock(inode);
|
|
if (mode & FALLOC_FL_PUNCH_HOLE) {
|
|
loff_t endbyte = offset + length - 1;
|
|
err = filemap_write_and_wait_range(inode->i_mapping,
|
|
offset, endbyte);
|
|
if (err)
|
|
goto out;
|
|
|
|
fuse_sync_writes(inode);
|
|
}
|
|
}
|
|
|
|
if (!(mode & FALLOC_FL_KEEP_SIZE))
|
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
|
|
args.in.h.opcode = FUSE_FALLOCATE;
|
|
args.in.h.nodeid = ff->nodeid;
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err == -ENOSYS) {
|
|
fc->no_fallocate = 1;
|
|
err = -EOPNOTSUPP;
|
|
}
|
|
if (err)
|
|
goto out;
|
|
|
|
/* we could have extended the file */
|
|
if (!(mode & FALLOC_FL_KEEP_SIZE)) {
|
|
bool changed = fuse_write_update_size(inode, offset + length);
|
|
|
|
if (changed && fc->writeback_cache)
|
|
file_update_time(file);
|
|
}
|
|
|
|
if (mode & FALLOC_FL_PUNCH_HOLE)
|
|
truncate_pagecache_range(inode, offset, offset + length - 1);
|
|
|
|
fuse_invalidate_attr(inode);
|
|
|
|
out:
|
|
if (!(mode & FALLOC_FL_KEEP_SIZE))
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
|
|
if (lock_inode)
|
|
inode_unlock(inode);
|
|
|
|
return err;
|
|
}
|
|
|
|
static const struct file_operations fuse_file_operations = {
|
|
.llseek = fuse_file_llseek,
|
|
.read_iter = fuse_file_read_iter,
|
|
.write_iter = fuse_file_write_iter,
|
|
.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,
|
|
.unlocked_ioctl = fuse_file_ioctl,
|
|
.compat_ioctl = fuse_file_compat_ioctl,
|
|
.poll = fuse_file_poll,
|
|
.fallocate = fuse_file_fallocate,
|
|
};
|
|
|
|
static const struct file_operations fuse_direct_io_file_operations = {
|
|
.llseek = fuse_file_llseek,
|
|
.read_iter = fuse_direct_read_iter,
|
|
.write_iter = fuse_direct_write_iter,
|
|
.mmap = fuse_direct_mmap,
|
|
.open = fuse_open,
|
|
.flush = fuse_flush,
|
|
.release = fuse_release,
|
|
.fsync = fuse_fsync,
|
|
.lock = fuse_file_lock,
|
|
.flock = fuse_file_flock,
|
|
.unlocked_ioctl = fuse_file_ioctl,
|
|
.compat_ioctl = fuse_file_compat_ioctl,
|
|
.poll = fuse_file_poll,
|
|
.fallocate = fuse_file_fallocate,
|
|
/* no splice_read */
|
|
};
|
|
|
|
static const struct address_space_operations fuse_file_aops = {
|
|
.readpage = fuse_readpage,
|
|
.writepage = fuse_writepage,
|
|
.writepages = fuse_writepages,
|
|
.launder_page = fuse_launder_page,
|
|
.readpages = fuse_readpages,
|
|
.set_page_dirty = __set_page_dirty_nobuffers,
|
|
.bmap = fuse_bmap,
|
|
.direct_IO = fuse_direct_IO,
|
|
.write_begin = fuse_write_begin,
|
|
.write_end = fuse_write_end,
|
|
};
|
|
|
|
void fuse_init_file_inode(struct inode *inode)
|
|
{
|
|
inode->i_fop = &fuse_file_operations;
|
|
inode->i_data.a_ops = &fuse_file_aops;
|
|
}
|