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kernel / pub / scm / linux / kernel / git / mkl / linux-can / 522ba450b56fff29f868b1552bdc2965f55de7ed / . / fs / fuse / file.c
blob: f1ef77a0be05bbee8991a0b1bdf61644e58b6c50 [file] [log] [blame]
/*
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/sched/signal.h>
#include <linux/module.h>
#include <linux/swap.h>
#include <linux/falloc.h>
#include <linux/uio.h>
#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/splice.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/iomap.h>
static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
unsigned int open_flags, int opcode,
struct fuse_open_out *outargp)
{
struct fuse_open_in inarg;
FUSE_ARGS(args);
memset(&inarg, 0, sizeof(inarg));
inarg.flags = open_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
if (!fm->fc->atomic_o_trunc)
inarg.flags &= ~O_TRUNC;
if (fm->fc->handle_killpriv_v2 &&
(inarg.flags & O_TRUNC) && !capable(CAP_FSETID)) {
inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
}
args.opcode = opcode;
args.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(fm, &args);
}
struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release)
{
struct fuse_file *ff;
ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL_ACCOUNT);
if (unlikely(!ff))
return NULL;
ff->fm = fm;
if (release) {
ff->args = kzalloc(sizeof(*ff->args), GFP_KERNEL_ACCOUNT);
if (!ff->args) {
kfree(ff);
return NULL;
}
}
INIT_LIST_HEAD(&ff->write_entry);
refcount_set(&ff->count, 1);
RB_CLEAR_NODE(&ff->polled_node);
init_waitqueue_head(&ff->poll_wait);
ff->kh = atomic64_inc_return(&fm->fc->khctr);
return ff;
}
void fuse_file_free(struct fuse_file *ff)
{
kfree(ff->args);
kfree(ff);
}
static struct fuse_file *fuse_file_get(struct fuse_file *ff)
{
refcount_inc(&ff->count);
return ff;
}
static void fuse_release_end(struct fuse_mount *fm, struct fuse_args *args,
int error)
{
struct fuse_release_args *ra = container_of(args, typeof(*ra), args);
iput(ra->inode);
kfree(ra);
}
static void fuse_file_put(struct fuse_file *ff, bool sync)
{
if (refcount_dec_and_test(&ff->count)) {
struct fuse_release_args *ra = &ff->args->release_args;
struct fuse_args *args = (ra ? &ra->args : NULL);
if (ra && ra->inode)
fuse_file_io_release(ff, ra->inode);
if (!args) {
/* Do nothing when server does not implement 'open' */
} else if (sync) {
fuse_simple_request(ff->fm, args);
fuse_release_end(ff->fm, args, 0);
} else {
args->end = fuse_release_end;
if (fuse_simple_background(ff->fm, args,
GFP_KERNEL | __GFP_NOFAIL))
fuse_release_end(ff->fm, args, -ENOTCONN);
}
kfree(ff);
}
}
struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
unsigned int open_flags, bool isdir)
{
struct fuse_conn *fc = fm->fc;
struct fuse_file *ff;
int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
bool open = isdir ? !fc->no_opendir : !fc->no_open;
ff = fuse_file_alloc(fm, open);
if (!ff)
return ERR_PTR(-ENOMEM);
ff->fh = 0;
/* Default for no-open */
ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0);
if (open) {
/* Store outarg for fuse_finish_open() */
struct fuse_open_out *outargp = &ff->args->open_outarg;
int err;
err = fuse_send_open(fm, nodeid, open_flags, opcode, outargp);
if (!err) {
ff->fh = outargp->fh;
ff->open_flags = outargp->open_flags;
} else if (err != -ENOSYS) {
fuse_file_free(ff);
return ERR_PTR(err);
} else {
/* No release needed */
kfree(ff->args);
ff->args = NULL;
if (isdir)
fc->no_opendir = 1;
else
fc->no_open = 1;
}
}
if (isdir)
ff->open_flags &= ~FOPEN_DIRECT_IO;
ff->nodeid = nodeid;
return ff;
}
int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
bool isdir)
{
struct fuse_file *ff = fuse_file_open(fm, nodeid, file->f_flags, isdir);
if (!IS_ERR(ff))
file->private_data = ff;
return PTR_ERR_OR_ZERO(ff);
}
EXPORT_SYMBOL_GPL(fuse_do_open);
static void fuse_link_write_file(struct file *file)
{
struct inode *inode = file_inode(file);
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(&fi->lock);
if (list_empty(&ff->write_entry))
list_add(&ff->write_entry, &fi->write_files);
spin_unlock(&fi->lock);
}
int fuse_finish_open(struct inode *inode, struct file *file)
{
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = get_fuse_conn(inode);
int err;
err = fuse_file_io_open(file, inode);
if (err)
return err;
if (ff->open_flags & FOPEN_STREAM)
stream_open(inode, file);
else if (ff->open_flags & FOPEN_NONSEEKABLE)
nonseekable_open(inode, file);
if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
fuse_link_write_file(file);
return 0;
}
static void fuse_truncate_update_attr(struct inode *inode, struct file *file)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
i_size_write(inode, 0);
spin_unlock(&fi->lock);
file_update_time(file);
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
}
static int fuse_open(struct inode *inode, struct file *file)
{
struct fuse_mount *fm = get_fuse_mount(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = fm->fc;
struct fuse_file *ff;
int err;
bool is_truncate = (file->f_flags & O_TRUNC) && fc->atomic_o_trunc;
bool is_wb_truncate = is_truncate && fc->writeback_cache;
bool dax_truncate = is_truncate && FUSE_IS_DAX(inode);
if (fuse_is_bad(inode))
return -EIO;
err = generic_file_open(inode, file);
if (err)
return err;
if (is_wb_truncate || dax_truncate)
inode_lock(inode);
if (dax_truncate) {
filemap_invalidate_lock(inode->i_mapping);
err = fuse_dax_break_layouts(inode, 0, -1);
if (err)
goto out_inode_unlock;
}
if (is_wb_truncate || dax_truncate)
fuse_set_nowrite(inode);
err = fuse_do_open(fm, get_node_id(inode), file, false);
if (!err) {
ff = file->private_data;
err = fuse_finish_open(inode, file);
if (err)
fuse_sync_release(fi, ff, file->f_flags);
else if (is_truncate)
fuse_truncate_update_attr(inode, file);
}
if (is_wb_truncate || dax_truncate)
fuse_release_nowrite(inode);
if (!err) {
if (is_truncate)
truncate_pagecache(inode, 0);
else if (!(ff->open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages2(inode->i_mapping);
}
if (dax_truncate)
filemap_invalidate_unlock(inode->i_mapping);
out_inode_unlock:
if (is_wb_truncate || dax_truncate)
inode_unlock(inode);
return err;
}
static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
unsigned int flags, int opcode, bool sync)
{
struct fuse_conn *fc = ff->fm->fc;
struct fuse_release_args *ra = &ff->args->release_args;
if (fuse_file_passthrough(ff))
fuse_passthrough_release(ff, fuse_inode_backing(fi));
/* Inode is NULL on error path of fuse_create_open() */
if (likely(fi)) {
spin_lock(&fi->lock);
list_del(&ff->write_entry);
spin_unlock(&fi->lock);
}
spin_lock(&fc->lock);
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);
if (!ra)
return;
/* ff->args was used for open outarg */
memset(ff->args, 0, sizeof(*ff->args));
ra->inarg.fh = ff->fh;
ra->inarg.flags = flags;
ra->args.in_numargs = 1;
ra->args.in_args[0].size = sizeof(struct fuse_release_in);
ra->args.in_args[0].value = &ra->inarg;
ra->args.opcode = opcode;
ra->args.nodeid = ff->nodeid;
ra->args.force = true;
ra->args.nocreds = true;
/*
* Hold inode until release is finished.
* From fuse_sync_release() the refcount is 1 and everything's
* synchronous, so we are fine with not doing igrab() here.
*/
ra->inode = sync ? NULL : igrab(&fi->inode);
}
void fuse_file_release(struct inode *inode, struct fuse_file *ff,
unsigned int open_flags, fl_owner_t id, bool isdir)
{
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_release_args *ra = &ff->args->release_args;
int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
fuse_prepare_release(fi, ff, open_flags, opcode, false);
if (ra && ff->flock) {
ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc, id);
}
/*
* 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.
*
* Always use the asynchronous file put because the current thread
* might be the fuse server. This can happen if a process starts some
* aio and closes the fd before the aio completes. Since aio takes its
* own ref to the file, the IO completion has to drop the ref, which is
* how the fuse server can end up closing its clients' files.
*/
fuse_file_put(ff, false);
}
void fuse_release_common(struct file *file, bool isdir)
{
fuse_file_release(file_inode(file), file->private_data, file->f_flags,
(fl_owner_t) file, isdir);
}
static int fuse_release(struct inode *inode, struct file *file)
{
struct fuse_conn *fc = get_fuse_conn(inode);
/*
* Dirty pages might remain despite write_inode_now() call from
* fuse_flush() due to writes racing with the close.
*/
if (fc->writeback_cache)
write_inode_now(inode, 1);
fuse_release_common(file, false);
/* return value is ignored by VFS */
return 0;
}
void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
unsigned int flags)
{
WARN_ON(refcount_read(&ff->count) > 1);
fuse_prepare_release(fi, ff, flags, FUSE_RELEASE, true);
fuse_file_put(ff, true);
}
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);
}
struct fuse_writepage_args {
struct fuse_io_args ia;
struct list_head queue_entry;
struct inode *inode;
struct fuse_sync_bucket *bucket;
};
/*
* 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_mount *fm = get_fuse_mount(inode);
struct fuse_file *ff = file->private_data;
struct fuse_flush_in inarg;
FUSE_ARGS(args);
int err;
if (fuse_is_bad(inode))
return -EIO;
if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
return 0;
err = write_inode_now(inode, 1);
if (err)
return err;
err = filemap_check_errors(file->f_mapping);
if (err)
return err;
err = 0;
if (fm->fc->no_flush)
goto inval_attr_out;
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
args.opcode = FUSE_FLUSH;
args.nodeid = get_node_id(inode);
args.in_numargs = 1;
args.in_args[0].size = sizeof(inarg);
args.in_args[0].value = &inarg;
args.force = true;
err = fuse_simple_request(fm, &args);
if (err == -ENOSYS) {
fm->fc->no_flush = 1;
err = 0;
}
inval_attr_out:
/*
* In memory i_blocks is not maintained by fuse, if writeback cache is
* enabled, i_blocks from cached attr may not be accurate.
*/
if (!err && fm->fc->writeback_cache)
fuse_invalidate_attr_mask(inode, STATX_BLOCKS);
return err;
}
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
int datasync, int opcode)
{
struct inode *inode = file->f_mapping->host;
struct fuse_mount *fm = get_fuse_mount(inode);
struct fuse_file *ff = file->private_data;
FUSE_ARGS(args);
struct fuse_fsync_in inarg;
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
inarg.fsync_flags = datasync ? FUSE_FSYNC_FDATASYNC : 0;
args.opcode = opcode;
args.nodeid = get_node_id(inode);
args.in_numargs = 1;
args.in_args[0].size = sizeof(inarg);
args.in_args[0].value = &inarg;
return fuse_simple_request(fm, &args);
}
static int fuse_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
struct inode *inode = file->f_mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
int err;
if (fuse_is_bad(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 = file_write_and_wait_range(file, start, end);
if (err)
goto out;
fuse_sync_writes(inode);
/*
* Due to implementation of fuse writeback
* file_write_and_wait_range() does not catch errors.
* We have to do this directly after fuse_sync_writes()
*/
err = file_check_and_advance_wb_err(file);
if (err)
goto out;
err = sync_inode_metadata(inode, 1);
if (err)
goto out;
if (fc->no_fsync)
goto out;
err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNC);
if (err == -ENOSYS) {
fc->no_fsync = 1;
err = 0;
}
out:
inode_unlock(inode);
return err;
}
void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
size_t count, int opcode)
{
struct fuse_file *ff = file->private_data;
struct fuse_args *args = &ia->ap.args;
ia->read.in.fh = ff->fh;
ia->read.in.offset = pos;
ia->read.in.size = count;
ia->read.in.flags = file->f_flags;
args->opcode = opcode;
args->nodeid = ff->nodeid;
args->in_numargs = 1;
args->in_args[0].size = sizeof(ia->read.in);
args->in_args[0].value = &ia->read.in;
args->out_argvar = true;
args->out_numargs = 1;
args->out_args[0].size = count;
}
static void fuse_release_user_pages(struct fuse_args_pages *ap, ssize_t nres,
bool should_dirty)
{
unsigned int i;
for (i = 0; i < ap->num_folios; i++) {
if (should_dirty)
folio_mark_dirty_lock(ap->folios[i]);
if (ap->args.is_pinned)
unpin_folio(ap->folios[i]);
}
if (nres > 0 && ap->args.invalidate_vmap)
invalidate_kernel_vmap_range(ap->args.vmap_base, nres);
}
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 split 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)
{
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 && io->blocking)
complete(io->done);
spin_unlock(&io->lock);
if (!left && !io->blocking) {
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(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
spin_unlock(&fi->lock);
}
io->iocb->ki_complete(io->iocb, res);
}
kref_put(&io->refcnt, fuse_io_release);
}
static struct fuse_io_args *fuse_io_alloc(struct fuse_io_priv *io,
unsigned int nfolios)
{
struct fuse_io_args *ia;
ia = kzalloc(sizeof(*ia), GFP_KERNEL);
if (ia) {
ia->io = io;
ia->ap.folios = fuse_folios_alloc(nfolios, GFP_KERNEL,
&ia->ap.descs);
if (!ia->ap.folios) {
kfree(ia);
ia = NULL;
}
}
return ia;
}
static void fuse_io_free(struct fuse_io_args *ia)
{
kfree(ia->ap.folios);
kfree(ia);
}
static void fuse_aio_complete_req(struct fuse_mount *fm, struct fuse_args *args,
int err)
{
struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
struct fuse_io_priv *io = ia->io;
ssize_t pos = -1;
size_t nres;
if (err) {
/* Nothing */
} else if (io->write) {
if (ia->write.out.size > ia->write.in.size) {
err = -EIO;
} else {
nres = ia->write.out.size;
if (ia->write.in.size != ia->write.out.size)
pos = ia->write.in.offset - io->offset +
ia->write.out.size;
}
} else {
u32 outsize = args->out_args[0].size;
nres = outsize;
if (ia->read.in.size != outsize)
pos = ia->read.in.offset - io->offset + outsize;
}
fuse_release_user_pages(&ia->ap, err ?: nres, io->should_dirty);
fuse_aio_complete(io, err, pos);
fuse_io_free(ia);
}
static ssize_t fuse_async_req_send(struct fuse_mount *fm,
struct fuse_io_args *ia, size_t num_bytes)
{
ssize_t err;
struct fuse_io_priv *io = ia->io;
spin_lock(&io->lock);
kref_get(&io->refcnt);
io->size += num_bytes;
io->reqs++;
spin_unlock(&io->lock);
ia->ap.args.end = fuse_aio_complete_req;
ia->ap.args.may_block = io->should_dirty;
err = fuse_simple_background(fm, &ia->ap.args, GFP_KERNEL);
if (err)
fuse_aio_complete_req(fm, &ia->ap.args, err);
return num_bytes;
}
static ssize_t fuse_send_read(struct fuse_io_args *ia, loff_t pos, size_t count,
fl_owner_t owner)
{
struct file *file = ia->io->iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct fuse_mount *fm = ff->fm;
fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
if (owner != NULL) {
ia->read.in.read_flags |= FUSE_READ_LOCKOWNER;
ia->read.in.lock_owner = fuse_lock_owner_id(fm->fc, owner);
}
if (ia->io->async)
return fuse_async_req_send(fm, ia, count);
return fuse_simple_request(fm, &ia->ap.args);
}
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(&fi->lock);
if (attr_ver >= fi->attr_version && size < inode->i_size &&
!test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
fi->attr_version = atomic64_inc_return(&fc->attr_version);
i_size_write(inode, size);
}
spin_unlock(&fi->lock);
}
static void fuse_short_read(struct inode *inode, u64 attr_ver, size_t num_read,
struct fuse_args_pages *ap)
{
struct fuse_conn *fc = get_fuse_conn(inode);
/*
* If writeback_cache is enabled, a short read means there's a hole in
* the file. Some data after the hole is in page cache, but has not
* reached the client fs yet. So the hole is not present there.
*/
if (!fc->writeback_cache) {
loff_t pos = folio_pos(ap->folios[0]) + num_read;
fuse_read_update_size(inode, pos, attr_ver);
}
}
static int fuse_do_readfolio(struct file *file, struct folio *folio,
size_t off, size_t len)
{
struct inode *inode = folio->mapping->host;
struct fuse_mount *fm = get_fuse_mount(inode);
loff_t pos = folio_pos(folio) + off;
struct fuse_folio_desc desc = {
.offset = off,
.length = len,
};
struct fuse_io_args ia = {
.ap.args.page_zeroing = true,
.ap.args.out_pages = true,
.ap.num_folios = 1,
.ap.folios = &folio,
.ap.descs = &desc,
};
ssize_t res;
u64 attr_ver;
attr_ver = fuse_get_attr_version(fm->fc);
/* Don't overflow end offset */
if (pos + (desc.length - 1) == LLONG_MAX)
desc.length--;
fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ);
res = fuse_simple_request(fm, &ia.ap.args);
if (res < 0)
return res;
/*
* Short read means EOF. If file size is larger, truncate it
*/
if (res < desc.length)
fuse_short_read(inode, attr_ver, res, &ia.ap);
return 0;
}
static int fuse_read_folio(struct file *file, struct folio *folio)
{
struct inode *inode = folio->mapping->host;
int err;
err = -EIO;
if (fuse_is_bad(inode))
goto out;
err = fuse_do_readfolio(file, folio, 0, folio_size(folio));
if (!err)
folio_mark_uptodate(folio);
fuse_invalidate_atime(inode);
out:
folio_unlock(folio);
return err;
}
static int fuse_iomap_read_folio_range(const struct iomap_iter *iter,
struct folio *folio, loff_t pos,
size_t len)
{
struct file *file = iter->private;
size_t off = offset_in_folio(folio, pos);
return fuse_do_readfolio(file, folio, off, len);
}
static void fuse_readpages_end(struct fuse_mount *fm, struct fuse_args *args,
int err)
{
int i;
struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
struct fuse_args_pages *ap = &ia->ap;
size_t count = ia->read.in.size;
size_t num_read = args->out_args[0].size;
struct address_space *mapping;
struct inode *inode;
WARN_ON_ONCE(!ap->num_folios);
mapping = ap->folios[0]->mapping;
inode = mapping->host;
/*
* Short read means EOF. If file size is larger, truncate it
*/
if (!err && num_read < count)
fuse_short_read(inode, ia->read.attr_ver, num_read, ap);
fuse_invalidate_atime(inode);
for (i = 0; i < ap->num_folios; i++) {
folio_end_read(ap->folios[i], !err);
folio_put(ap->folios[i]);
}
if (ia->ff)
fuse_file_put(ia->ff, false);
fuse_io_free(ia);
}
static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file,
unsigned int count)
{
struct fuse_file *ff = file->private_data;
struct fuse_mount *fm = ff->fm;
struct fuse_args_pages *ap = &ia->ap;
loff_t pos = folio_pos(ap->folios[0]);
ssize_t res;
int err;
ap->args.out_pages = true;
ap->args.page_zeroing = true;
ap->args.page_replace = true;
/* Don't overflow end offset */
if (pos + (count - 1) == LLONG_MAX) {
count--;
ap->descs[ap->num_folios - 1].length--;
}
WARN_ON((loff_t) (pos + count) < 0);
fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
ia->read.attr_ver = fuse_get_attr_version(fm->fc);
if (fm->fc->async_read) {
ia->ff = fuse_file_get(ff);
ap->args.end = fuse_readpages_end;
err = fuse_simple_background(fm, &ap->args, GFP_KERNEL);
if (!err)
return;
} else {
res = fuse_simple_request(fm, &ap->args);
err = res < 0 ? res : 0;
}
fuse_readpages_end(fm, &ap->args, err);
}
static void fuse_readahead(struct readahead_control *rac)
{
struct inode *inode = rac->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
unsigned int max_pages, nr_pages;
struct folio *folio = NULL;
if (fuse_is_bad(inode))
return;
max_pages = min_t(unsigned int, fc->max_pages,
fc->max_read / PAGE_SIZE);
/*
* This is only accurate the first time through, since readahead_folio()
* doesn't update readahead_count() from the previous folio until the
* next call. Grab nr_pages here so we know how many pages we're going
* to have to process. This means that we will exit here with
* readahead_count() == folio_nr_pages(last_folio), but we will have
* consumed all of the folios, and read_pages() will call
* readahead_folio() again which will clean up the rac.
*/
nr_pages = readahead_count(rac);
while (nr_pages) {
struct fuse_io_args *ia;
struct fuse_args_pages *ap;
unsigned cur_pages = min(max_pages, nr_pages);
unsigned int pages = 0;
if (fc->num_background >= fc->congestion_threshold &&
rac->ra->async_size >= readahead_count(rac))
/*
* Congested and only async pages left, so skip the
* rest.
*/
break;
ia = fuse_io_alloc(NULL, cur_pages);
if (!ia)
break;
ap = &ia->ap;
while (pages < cur_pages) {
unsigned int folio_pages;
/*
* This returns a folio with a ref held on it.
* The ref needs to be held until the request is
* completed, since the splice case (see
* fuse_try_move_page()) drops the ref after it's
* replaced in the page cache.
*/
if (!folio)
folio = __readahead_folio(rac);
folio_pages = folio_nr_pages(folio);
if (folio_pages > cur_pages - pages) {
/*
* Large folios belonging to fuse will never
* have more pages than max_pages.
*/
WARN_ON(!pages);
break;
}
ap->folios[ap->num_folios] = folio;
ap->descs[ap->num_folios].length = folio_size(folio);
ap->num_folios++;
pages += folio_pages;
folio = NULL;
}
fuse_send_readpages(ia, rac->file, pages << PAGE_SHIFT);
nr_pages -= pages;
}
if (folio) {
folio_end_read(folio, false);
folio_put(folio);
}
}
static ssize_t fuse_cache_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, iocb->ki_filp, STATX_SIZE);
if (err)
return err;
}
return generic_file_read_iter(iocb, to);
}
static void fuse_write_args_fill(struct fuse_io_args *ia, struct fuse_file *ff,
loff_t pos, size_t count)
{
struct fuse_args *args = &ia->ap.args;
ia->write.in.fh = ff->fh;
ia->write.in.offset = pos;
ia->write.in.size = count;
args->opcode = FUSE_WRITE;
args->nodeid = ff->nodeid;
args->in_numargs = 2;
if (ff->fm->fc->minor < 9)
args->in_args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
else
args->in_args[0].size = sizeof(ia->write.in);
args->in_args[0].value = &ia->write.in;
args->in_args[1].size = count;
args->out_numargs = 1;
args->out_args[0].size = sizeof(ia->write.out);
args->out_args[0].value = &ia->write.out;
}
static unsigned int fuse_write_flags(struct kiocb *iocb)
{
unsigned int flags = iocb->ki_filp->f_flags;
if (iocb_is_dsync(iocb))
flags |= O_DSYNC;
if (iocb->ki_flags & IOCB_SYNC)
flags |= O_SYNC;
return flags;
}
static ssize_t fuse_send_write(struct fuse_io_args *ia, loff_t pos,
size_t count, fl_owner_t owner)
{
struct kiocb *iocb = ia->io->iocb;
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct fuse_mount *fm = ff->fm;
struct fuse_write_in *inarg = &ia->write.in;
ssize_t err;
fuse_write_args_fill(ia, ff, pos, count);
inarg->flags = fuse_write_flags(iocb);
if (owner != NULL) {
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
inarg->lock_owner = fuse_lock_owner_id(fm->fc, owner);
}
if (ia->io->async)
return fuse_async_req_send(fm, ia, count);
err = fuse_simple_request(fm, &ia->ap.args);
if (!err && ia->write.out.size > count)
err = -EIO;
return err ?: ia->write.out.size;
}
bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
bool ret = false;
spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
if (written > 0 && pos > inode->i_size) {
i_size_write(inode, pos);
ret = true;
}
spin_unlock(&fi->lock);
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
return ret;
}
static ssize_t fuse_send_write_pages(struct fuse_io_args *ia,
struct kiocb *iocb, struct inode *inode,
loff_t pos, size_t count)
{
struct fuse_args_pages *ap = &ia->ap;
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct fuse_mount *fm = ff->fm;
unsigned int offset, i;
bool short_write;
int err;
for (i = 0; i < ap->num_folios; i++)
folio_wait_writeback(ap->folios[i]);
fuse_write_args_fill(ia, ff, pos, count);
ia->write.in.flags = fuse_write_flags(iocb);
if (fm->fc->handle_killpriv_v2 && !capable(CAP_FSETID))
ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
err = fuse_simple_request(fm, &ap->args);
if (!err && ia->write.out.size > count)
err = -EIO;
short_write = ia->write.out.size < count;
offset = ap->descs[0].offset;
count = ia->write.out.size;
for (i = 0; i < ap->num_folios; i++) {
struct folio *folio = ap->folios[i];
if (err) {
folio_clear_uptodate(folio);
} else {
if (count >= folio_size(folio) - offset)
count -= folio_size(folio) - offset;
else {
if (short_write)
folio_clear_uptodate(folio);
count = 0;
}
offset = 0;
}
if (ia->write.folio_locked && (i == ap->num_folios - 1))
folio_unlock(folio);
folio_put(folio);
}
return err;
}
static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
struct address_space *mapping,
struct iov_iter *ii, loff_t pos,
unsigned int max_folios)
{
struct fuse_args_pages *ap = &ia->ap;
struct fuse_conn *fc = get_fuse_conn(mapping->host);
unsigned offset = pos & (PAGE_SIZE - 1);
size_t count = 0;
unsigned int num;
int err = 0;
num = min(iov_iter_count(ii), fc->max_write);
ap->args.in_pages = true;
while (num && ap->num_folios < max_folios) {
size_t tmp;
struct folio *folio;
pgoff_t index = pos >> PAGE_SHIFT;
unsigned int bytes;
unsigned int folio_offset;
again:
folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
mapping_gfp_mask(mapping));
if (IS_ERR(folio)) {
err = PTR_ERR(folio);
break;
}
if (mapping_writably_mapped(mapping))
flush_dcache_folio(folio);
folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
bytes = min(folio_size(folio) - folio_offset, num);
tmp = copy_folio_from_iter_atomic(folio, folio_offset, bytes, ii);
flush_dcache_folio(folio);
if (!tmp) {
folio_unlock(folio);
folio_put(folio);
/*
* Ensure forward progress by faulting in
* while not holding the folio lock:
*/
if (fault_in_iov_iter_readable(ii, bytes)) {
err = -EFAULT;
break;
}
goto again;
}
ap->folios[ap->num_folios] = folio;
ap->descs[ap->num_folios].offset = folio_offset;
ap->descs[ap->num_folios].length = tmp;
ap->num_folios++;
count += tmp;
pos += tmp;
num -= tmp;
offset += tmp;
if (offset == folio_size(folio))
offset = 0;
/* If we copied full folio, mark it uptodate */
if (tmp == folio_size(folio))
folio_mark_uptodate(folio);
if (folio_test_uptodate(folio)) {
folio_unlock(folio);
} else {
ia->write.folio_locked = true;
break;
}
if (!fc->big_writes || offset != 0)
break;
}
return count > 0 ? count : err;
}
static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
unsigned int max_pages)
{
return min_t(unsigned int,
((pos + len - 1) >> PAGE_SHIFT) -
(pos >> PAGE_SHIFT) + 1,
max_pages);
}
static ssize_t fuse_perform_write(struct kiocb *iocb, struct iov_iter *ii)
{
struct address_space *mapping = iocb->ki_filp->f_mapping;
struct inode *inode = mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
loff_t pos = iocb->ki_pos;
int err = 0;
ssize_t res = 0;
if (inode->i_size < pos + iov_iter_count(ii))
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
do {
ssize_t count;
struct fuse_io_args ia = {};
struct fuse_args_pages *ap = &ia.ap;
unsigned int nr_pages = fuse_wr_pages(pos, iov_iter_count(ii),
fc->max_pages);
ap->folios = fuse_folios_alloc(nr_pages, GFP_KERNEL, &ap->descs);
if (!ap->folios) {
err = -ENOMEM;
break;
}
count = fuse_fill_write_pages(&ia, mapping, ii, pos, nr_pages);
if (count <= 0) {
err = count;
} else {
err = fuse_send_write_pages(&ia, iocb, inode,
pos, count);
if (!err) {
size_t num_written = ia.write.out.size;
res += num_written;
pos += num_written;
/* break out of the loop on short write */
if (num_written != count)
err = -EIO;
}
}
kfree(ap->folios);
} while (!err && iov_iter_count(ii));
fuse_write_update_attr(inode, pos, res);
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
if (!res)
return err;
iocb->ki_pos += res;
return res;
}
static bool fuse_io_past_eof(struct kiocb *iocb, struct iov_iter *iter)
{
struct inode *inode = file_inode(iocb->ki_filp);
return iocb->ki_pos + iov_iter_count(iter) > i_size_read(inode);
}
/*
* @return true if an exclusive lock for direct IO writes is needed
*/
static bool fuse_dio_wr_exclusive_lock(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct inode *inode = file_inode(iocb->ki_filp);
struct fuse_inode *fi = get_fuse_inode(inode);
/* Server side has to advise that it supports parallel dio writes. */
if (!(ff->open_flags & FOPEN_PARALLEL_DIRECT_WRITES))
return true;
/*
* Append will need to know the eventual EOF - always needs an
* exclusive lock.
*/
if (iocb->ki_flags & IOCB_APPEND)
return true;
/* shared locks are not allowed with parallel page cache IO */
if (test_bit(FUSE_I_CACHE_IO_MODE, &fi->state))
return true;
/* Parallel dio beyond EOF is not supported, at least for now. */
if (fuse_io_past_eof(iocb, from))
return true;
return false;
}
static void fuse_dio_lock(struct kiocb *iocb, struct iov_iter *from,
bool *exclusive)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct fuse_inode *fi = get_fuse_inode(inode);
*exclusive = fuse_dio_wr_exclusive_lock(iocb, from);
if (*exclusive) {
inode_lock(inode);
} else {
inode_lock_shared(inode);
/*
* New parallal dio allowed only if inode is not in caching
* mode and denies new opens in caching mode. This check
* should be performed only after taking shared inode lock.
* Previous past eof check was without inode lock and might
* have raced, so check it again.
*/
if (fuse_io_past_eof(iocb, from) ||
fuse_inode_uncached_io_start(fi, NULL) != 0) {
inode_unlock_shared(inode);
inode_lock(inode);
*exclusive = true;
}
}
}
static void fuse_dio_unlock(struct kiocb *iocb, bool exclusive)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct fuse_inode *fi = get_fuse_inode(inode);
if (exclusive) {
inode_unlock(inode);
} else {
/* Allow opens in caching mode after last parallel dio end */
fuse_inode_uncached_io_end(fi);
inode_unlock_shared(inode);
}
}
static const struct iomap_write_ops fuse_iomap_write_ops = {
.read_folio_range = fuse_iomap_read_folio_range,
};
static int fuse_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned int flags, struct iomap *iomap,
struct iomap *srcmap)
{
iomap->type = IOMAP_MAPPED;
iomap->length = length;
iomap->offset = offset;
return 0;
}
static const struct iomap_ops fuse_iomap_ops = {
.iomap_begin = fuse_iomap_begin,
};
static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct mnt_idmap *idmap = file_mnt_idmap(file);
struct address_space *mapping = file->f_mapping;
ssize_t written = 0;
struct inode *inode = mapping->host;
ssize_t err, count;
struct fuse_conn *fc = get_fuse_conn(inode);
bool writeback = false;
if (fc->writeback_cache) {
/* Update size (EOF optimization) and mode (SUID clearing) */
err = fuse_update_attributes(mapping->host, file,
STATX_SIZE | STATX_MODE);
if (err)
return err;
if (!fc->handle_killpriv_v2 ||
!setattr_should_drop_suidgid(idmap, file_inode(file)))
writeback = true;
}
inode_lock(inode);
err = count = generic_write_checks(iocb, from);
if (err <= 0)
goto out;
task_io_account_write(count);
err = kiocb_modified(iocb);
if (err)
goto out;
if (iocb->ki_flags & IOCB_DIRECT) {
written = generic_file_direct_write(iocb, from);
if (written < 0 || !iov_iter_count(from))
goto out;
written = direct_write_fallback(iocb, from, written,
fuse_perform_write(iocb, from));
} else if (writeback) {
/*
* Use iomap so that we can do granular uptodate reads
* and granular dirty tracking for large folios.
*/
written = iomap_file_buffered_write(iocb, from,
&fuse_iomap_ops,
&fuse_iomap_write_ops,
file);
} else {
written = fuse_perform_write(iocb, from);
}
out:
inode_unlock(inode);
if (written > 0)
written = generic_write_sync(iocb, written);
return written ? written : err;
}
static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
{
return (unsigned long)iter_iov(ii)->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_args_pages *ap, struct iov_iter *ii,
size_t *nbytesp, int write,
unsigned int max_pages,
bool use_pages_for_kvec_io)
{
bool flush_or_invalidate = false;
unsigned int nr_pages = 0;
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.
* However if the implementation of fuse_conn requires pages instead of
* pointer (e.g., virtio-fs), use iov_iter_extract_pages() instead.
*/
if (iov_iter_is_kvec(ii)) {
void *user_addr = (void *)fuse_get_user_addr(ii);
if (!use_pages_for_kvec_io) {
size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
if (write)
ap->args.in_args[1].value = user_addr;
else
ap->args.out_args[0].value = user_addr;
iov_iter_advance(ii, frag_size);
*nbytesp = frag_size;
return 0;
}
if (is_vmalloc_addr(user_addr)) {
ap->args.vmap_base = user_addr;
flush_or_invalidate = true;
}
}
/*
* Until there is support for iov_iter_extract_folios(), we have to
* manually extract pages using iov_iter_extract_pages() and then
* copy that to a folios array.
*/
struct page **pages = kzalloc(max_pages * sizeof(struct page *),
GFP_KERNEL);
if (!pages) {
ret = -ENOMEM;
goto out;
}
while (nbytes < *nbytesp && nr_pages < max_pages) {
unsigned nfolios, i;
size_t start;
ret = iov_iter_extract_pages(ii, &pages,
*nbytesp - nbytes,
max_pages - nr_pages,
0, &start);
if (ret < 0)
break;
nbytes += ret;
nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE);
for (i = 0; i < nfolios; i++) {
struct folio *folio = page_folio(pages[i]);
unsigned int offset = start +
(folio_page_idx(folio, pages[i]) << PAGE_SHIFT);
unsigned int len = min_t(unsigned int, ret, PAGE_SIZE - start);
ap->descs[ap->num_folios].offset = offset;
ap->descs[ap->num_folios].length = len;
ap->folios[ap->num_folios] = folio;
start = 0;
ret -= len;
ap->num_folios++;
}
nr_pages += nfolios;
}
kfree(pages);
if (write && flush_or_invalidate)
flush_kernel_vmap_range(ap->args.vmap_base, nbytes);
ap->args.invalidate_vmap = !write && flush_or_invalidate;
ap->args.is_pinned = iov_iter_extract_will_pin(ii);
ap->args.user_pages = true;
if (write)
ap->args.in_pages = true;
else
ap->args.out_pages = true;
out:
*nbytesp = nbytes;
return ret < 0 ? ret : 0;
}
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->iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fm->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;
int err = 0;
struct fuse_io_args *ia;
unsigned int max_pages;
bool fopen_direct_io = ff->open_flags & FOPEN_DIRECT_IO;
max_pages = iov_iter_npages(iter, fc->max_pages);
ia = fuse_io_alloc(io, max_pages);
if (!ia)
return -ENOMEM;
if (fopen_direct_io && fc->direct_io_allow_mmap) {
res = filemap_write_and_wait_range(mapping, pos, pos + count - 1);
if (res) {
fuse_io_free(ia);
return res;
}
}
if (!cuse && filemap_range_has_writeback(mapping, pos, (pos + count - 1))) {
if (!write)
inode_lock(inode);
fuse_sync_writes(inode);
if (!write)
inode_unlock(inode);
}
if (fopen_direct_io && write) {
res = invalidate_inode_pages2_range(mapping, idx_from, idx_to);
if (res) {
fuse_io_free(ia);
return res;
}
}
io->should_dirty = !write && user_backed_iter(iter);
while (count) {
ssize_t nres;
fl_owner_t owner = current->files;
size_t nbytes = min(count, nmax);
err = fuse_get_user_pages(&ia->ap, iter, &nbytes, write,
max_pages, fc->use_pages_for_kvec_io);
if (err && !nbytes)
break;
if (write) {
if (!capable(CAP_FSETID))
ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
nres = fuse_send_write(ia, pos, nbytes, owner);
} else {
nres = fuse_send_read(ia, pos, nbytes, owner);
}
if (!io->async || nres < 0) {
fuse_release_user_pages(&ia->ap, nres, io->should_dirty);
fuse_io_free(ia);
}
ia = NULL;
if (nres < 0) {
iov_iter_revert(iter, nbytes);
err = nres;
break;
}
WARN_ON(nres > nbytes);
count -= nres;
res += nres;
pos += nres;
if (nres != nbytes) {
iov_iter_revert(iter, nbytes - nres);
break;
}
if (count) {
max_pages = iov_iter_npages(iter, fc->max_pages);
ia = fuse_io_alloc(io, max_pages);
if (!ia)
break;
}
}
if (ia)
fuse_io_free(ia);
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 inode *inode = file_inode(io->iocb->ki_filp);
res = fuse_direct_io(io, iter, ppos, 0);
fuse_invalidate_atime(inode);
return res;
}
static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
ssize_t res;
if (!is_sync_kiocb(iocb)) {
res = fuse_direct_IO(iocb, to);
} else {
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
res = __fuse_direct_read(&io, to, &iocb->ki_pos);
}
return res;
}
static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
ssize_t res;
bool exclusive;
fuse_dio_lock(iocb, from, &exclusive);
res = generic_write_checks(iocb, from);
if (res > 0) {
task_io_account_write(res);
if (!is_sync_kiocb(iocb)) {
res = fuse_direct_IO(iocb, from);
} else {
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
res = fuse_direct_io(&io, from, &iocb->ki_pos,
FUSE_DIO_WRITE);
fuse_write_update_attr(inode, iocb->ki_pos, res);
}
}
fuse_dio_unlock(iocb, exclusive);
return res;
}
static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct inode *inode = file_inode(file);
if (fuse_is_bad(inode))
return -EIO;
if (FUSE_IS_DAX(inode))
return fuse_dax_read_iter(iocb, to);
/* FOPEN_DIRECT_IO overrides FOPEN_PASSTHROUGH */
if (ff->open_flags & FOPEN_DIRECT_IO)
return fuse_direct_read_iter(iocb, to);
else if (fuse_file_passthrough(ff))
return fuse_passthrough_read_iter(iocb, to);
else
return fuse_cache_read_iter(iocb, to);
}
static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
struct inode *inode = file_inode(file);
if (fuse_is_bad(inode))
return -EIO;
if (FUSE_IS_DAX(inode))
return fuse_dax_write_iter(iocb, from);
/* FOPEN_DIRECT_IO overrides FOPEN_PASSTHROUGH */
if (ff->open_flags & FOPEN_DIRECT_IO)
return fuse_direct_write_iter(iocb, from);
else if (fuse_file_passthrough(ff))
return fuse_passthrough_write_iter(iocb, from);
else
return fuse_cache_write_iter(iocb, from);
}
static ssize_t fuse_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
struct fuse_file *ff = in->private_data;
/* FOPEN_DIRECT_IO overrides FOPEN_PASSTHROUGH */
if (fuse_file_passthrough(ff) && !(ff->open_flags & FOPEN_DIRECT_IO))
return fuse_passthrough_splice_read(in, ppos, pipe, len, flags);
else
return filemap_splice_read(in, ppos, pipe, len, flags);
}
static ssize_t fuse_splice_write(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
struct fuse_file *ff = out->private_data;
/* FOPEN_DIRECT_IO overrides FOPEN_PASSTHROUGH */
if (fuse_file_passthrough(ff) && !(ff->open_flags & FOPEN_DIRECT_IO))
return fuse_passthrough_splice_write(pipe, out, ppos, len, flags);
else
return iter_file_splice_write(pipe, out, ppos, len, flags);
}
static void fuse_writepage_free(struct fuse_writepage_args *wpa)
{
struct fuse_args_pages *ap = &wpa->ia.ap;
if (wpa->bucket)
fuse_sync_bucket_dec(wpa->bucket);
fuse_file_put(wpa->ia.ff, false);
kfree(ap->folios);
kfree(wpa);
}
static void fuse_writepage_finish(struct fuse_writepage_args *wpa)
{
struct fuse_args_pages *ap = &wpa->ia.ap;
struct inode *inode = wpa->inode;
struct fuse_inode *fi = get_fuse_inode(inode);
int i;
for (i = 0; i < ap->num_folios; i++)
/*
* Benchmarks showed that ending writeback within the
* scope of the fi->lock alleviates xarray lock
* contention and noticeably improves performance.
*/
iomap_finish_folio_write(inode, ap->folios[i], 1);
wake_up(&fi->page_waitq);
}
/* Called under fi->lock, may release and reacquire it */
static void fuse_send_writepage(struct fuse_mount *fm,
struct fuse_writepage_args *wpa, loff_t size)
__releases(fi->lock)
__acquires(fi->lock)
{
struct fuse_inode *fi = get_fuse_inode(wpa->inode);
struct fuse_args_pages *ap = &wpa->ia.ap;
struct fuse_write_in *inarg = &wpa->ia.write.in;
struct fuse_args *args = &ap->args;
__u64 data_size = 0;
int err, i;
for (i = 0; i < ap->num_folios; i++)
data_size += ap->descs[i].length;
fi->writectr++;
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;
}
args->in_args[1].size = inarg->size;
args->force = true;
args->nocreds = true;
err = fuse_simple_background(fm, args, GFP_ATOMIC);
if (err == -ENOMEM) {
spin_unlock(&fi->lock);
err = fuse_simple_background(fm, args, GFP_NOFS | __GFP_NOFAIL);
spin_lock(&fi->lock);
}
/* Fails on broken connection only */
if (unlikely(err))
goto out_free;
return;
out_free:
fi->writectr--;
fuse_writepage_finish(wpa);
spin_unlock(&fi->lock);
fuse_writepage_free(wpa);
spin_lock(&fi->lock);
}
/*
* If fi->writectr is positive (no truncate or fsync going on) send
* all queued writepage requests.
*
* Called with fi->lock
*/
void fuse_flush_writepages(struct inode *inode)
__releases(fi->lock)
__acquires(fi->lock)
{
struct fuse_mount *fm = get_fuse_mount(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
loff_t crop = i_size_read(inode);
struct fuse_writepage_args *wpa;
while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
wpa = list_entry(fi->queued_writes.next,
struct fuse_writepage_args, queue_entry);
list_del_init(&wpa->queue_entry);
fuse_send_writepage(fm, wpa, crop);
}
}
static void fuse_writepage_end(struct fuse_mount *fm, struct fuse_args *args,
int error)
{
struct fuse_writepage_args *wpa =
container_of(args, typeof(*wpa), ia.ap.args);
struct inode *inode = wpa->inode;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
mapping_set_error(inode->i_mapping, error);
/*
* A writeback finished and this might have updated mtime/ctime on
* server making local mtime/ctime stale. Hence invalidate attrs.
* Do this only if writeback_cache is not enabled. If writeback_cache
* is enabled, we trust local ctime/mtime.
*/
if (!fc->writeback_cache)
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODIFY);
spin_lock(&fi->lock);
fi->writectr--;
fuse_writepage_finish(wpa);
spin_unlock(&fi->lock);
fuse_writepage_free(wpa);
}
static struct fuse_file *__fuse_write_file_get(struct fuse_inode *fi)
{
struct fuse_file *ff;
spin_lock(&fi->lock);
ff = list_first_entry_or_null(&fi->write_files, struct fuse_file,
write_entry);
if (ff)
fuse_file_get(ff);
spin_unlock(&fi->lock);
return ff;
}
static struct fuse_file *fuse_write_file_get(struct fuse_inode *fi)
{
struct fuse_file *ff = __fuse_write_file_get(fi);
WARN_ON(!ff);
return ff;
}
int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_file *ff;
int err;
ff = __fuse_write_file_get(fi);
err = fuse_flush_times(inode, ff);
if (ff)
fuse_file_put(ff, false);
return err;
}
static struct fuse_writepage_args *fuse_writepage_args_alloc(void)
{
struct fuse_writepage_args *wpa;
struct fuse_args_pages *ap;
wpa = kzalloc(sizeof(*wpa), GFP_NOFS);
if (wpa) {
ap = &wpa->ia.ap;
ap->num_folios = 0;
ap->folios = fuse_folios_alloc(1, GFP_NOFS, &ap->descs);
if (!ap->folios) {
kfree(wpa);
wpa = NULL;
}
}
return wpa;
}
static void fuse_writepage_add_to_bucket(struct fuse_conn *fc,
struct fuse_writepage_args *wpa)
{
if (!fc->sync_fs)
return;
rcu_read_lock();
/* Prevent resurrection of dead bucket in unlikely race with syncfs */
do {
wpa->bucket = rcu_dereference(fc->curr_bucket);
} while (unlikely(!atomic_inc_not_zero(&wpa->bucket->count)));
rcu_read_unlock();
}
static void fuse_writepage_args_page_fill(struct fuse_writepage_args *wpa, struct folio *folio,
uint32_t folio_index, loff_t offset, unsigned len)
{
struct fuse_args_pages *ap = &wpa->ia.ap;
ap->folios[folio_index] = folio;
ap->descs[folio_index].offset = offset;
ap->descs[folio_index].length = len;
}
static struct fuse_writepage_args *fuse_writepage_args_setup(struct folio *folio,
size_t offset,
struct fuse_file *ff)
{
struct inode *inode = folio->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_writepage_args *wpa;
struct fuse_args_pages *ap;
wpa = fuse_writepage_args_alloc();
if (!wpa)
return NULL;
fuse_writepage_add_to_bucket(fc, wpa);
fuse_write_args_fill(&wpa->ia, ff, folio_pos(folio) + offset, 0);
wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
wpa->inode = inode;
wpa->ia.ff = ff;
ap = &wpa->ia.ap;
ap->args.in_pages = true;
ap->args.end = fuse_writepage_end;
return wpa;
}
struct fuse_fill_wb_data {
struct fuse_writepage_args *wpa;
struct fuse_file *ff;
unsigned int max_folios;
/*
* nr_bytes won't overflow since fuse_writepage_need_send() caps
* wb requests to never exceed fc->max_pages (which has an upper bound
* of U16_MAX).
*/
unsigned int nr_bytes;
};
static bool fuse_pages_realloc(struct fuse_fill_wb_data *data,
unsigned int max_pages)
{
struct fuse_args_pages *ap = &data->wpa->ia.ap;
struct folio **folios;
struct fuse_folio_desc *descs;
unsigned int nfolios = min_t(unsigned int,
max_t(unsigned int, data->max_folios * 2,
FUSE_DEFAULT_MAX_PAGES_PER_REQ),
max_pages);
WARN_ON(nfolios <= data->max_folios);
folios = fuse_folios_alloc(nfolios, GFP_NOFS, &descs);
if (!folios)
return false;
memcpy(folios, ap->folios, sizeof(struct folio *) * ap->num_folios);
memcpy(descs, ap->descs, sizeof(struct fuse_folio_desc) * ap->num_folios);
kfree(ap->folios);
ap->folios = folios;
ap->descs = descs;
data->max_folios = nfolios;
return true;
}
static void fuse_writepages_send(struct inode *inode,
struct fuse_fill_wb_data *data)
{
struct fuse_writepage_args *wpa = data->wpa;
struct fuse_inode *fi = get_fuse_inode(inode);
spin_lock(&fi->lock);
list_add_tail(&wpa->queue_entry, &fi->queued_writes);
fuse_flush_writepages(inode);
spin_unlock(&fi->lock);
}
static bool fuse_writepage_need_send(struct fuse_conn *fc, loff_t pos,
unsigned len, struct fuse_args_pages *ap,
struct fuse_fill_wb_data *data)
{
struct folio *prev_folio;
struct fuse_folio_desc prev_desc;
unsigned bytes = data->nr_bytes + len;
loff_t prev_pos;
WARN_ON(!ap->num_folios);
/* Reached max pages */
if ((bytes + PAGE_SIZE - 1) >> PAGE_SHIFT > fc->max_pages)
return true;
/* Reached max write bytes */
if (bytes > fc->max_write)
return true;
/* Discontinuity */
prev_folio = ap->folios[ap->num_folios - 1];
prev_desc = ap->descs[ap->num_folios - 1];
prev_pos = folio_pos(prev_folio) + prev_desc.offset + prev_desc.length;
if (prev_pos != pos)
return true;
/* Need to grow the pages array? If so, did the expansion fail? */
if (ap->num_folios == data->max_folios &&
!fuse_pages_realloc(data, fc->max_pages))
return true;
return false;
}
static ssize_t fuse_iomap_writeback_range(struct iomap_writepage_ctx *wpc,
struct folio *folio, u64 pos,
unsigned len, u64 end_pos)
{
struct fuse_fill_wb_data *data = wpc->wb_ctx;
struct fuse_writepage_args *wpa = data->wpa;
struct fuse_args_pages *ap = &wpa->ia.ap;
struct inode *inode = wpc->inode;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
loff_t offset = offset_in_folio(folio, pos);
WARN_ON_ONCE(!data);
if (!data->ff) {
data->ff = fuse_write_file_get(fi);
if (!data->ff)
return -EIO;
}
if (wpa && fuse_writepage_need_send(fc, pos, len, ap, data)) {
fuse_writepages_send(inode, data);
data->wpa = NULL;
data->nr_bytes = 0;
}
if (data->wpa == NULL) {
wpa = fuse_writepage_args_setup(folio, offset, data->ff);
if (!wpa)
return -ENOMEM;
fuse_file_get(wpa->ia.ff);
data->max_folios = 1;
ap = &wpa->ia.ap;
}
iomap_start_folio_write(inode, folio, 1);
fuse_writepage_args_page_fill(wpa, folio, ap->num_folios,
offset, len);
data->nr_bytes += len;
ap->num_folios++;
if (!data->wpa)
data->wpa = wpa;
return len;
}
static int fuse_iomap_writeback_submit(struct iomap_writepage_ctx *wpc,
int error)
{
struct fuse_fill_wb_data *data = wpc->wb_ctx;
WARN_ON_ONCE(!data);
if (data->wpa) {
WARN_ON(!data->wpa->ia.ap.num_folios);
fuse_writepages_send(wpc->inode, data);
}
if (data->ff)
fuse_file_put(data->ff, false);
return error;
}
static const struct iomap_writeback_ops fuse_writeback_ops = {
.writeback_range = fuse_iomap_writeback_range,
.writeback_submit = fuse_iomap_writeback_submit,
};
static int fuse_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct inode *inode = mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_fill_wb_data data = {};
struct iomap_writepage_ctx wpc = {
.inode = inode,
.iomap.type = IOMAP_MAPPED,
.wbc = wbc,
.ops = &fuse_writeback_ops,
.wb_ctx = &data,
};
if (fuse_is_bad(inode))
return -EIO;
if (wbc->sync_mode == WB_SYNC_NONE &&
fc->num_background >= fc->congestion_threshold)
return 0;
return iomap_writepages(&wpc);
}
static int fuse_launder_folio(struct folio *folio)
{
int err = 0;
struct fuse_fill_wb_data data = {};
struct iomap_writepage_ctx wpc = {
.inode = folio->mapping->host,
.iomap.type = IOMAP_MAPPED,
.ops = &fuse_writeback_ops,
.wb_ctx = &data,
};
if (folio_clear_dirty_for_io(folio)) {
err = iomap_writeback_folio(&wpc, folio);
err = fuse_iomap_writeback_submit(&wpc, err);
if (!err)
folio_wait_writeback(folio);
}
return err;
}
/*
* Write back dirty data/metadata now (there may not be any suitable
* open files later for data)
*/
static void fuse_vma_close(struct vm_area_struct *vma)
{
int err;
err = write_inode_now(vma->vm_file->f_mapping->host, 1);
mapping_set_error(vma->vm_file->f_mapping, err);
}
/*
* 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 vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf)
{
struct folio *folio = page_folio(vmf->page);
struct inode *inode = file_inode(vmf->vma->vm_file);
file_update_time(vmf->vma->vm_file);
folio_lock(folio);
if (folio->mapping != inode->i_mapping) {
folio_unlock(folio);
return VM_FAULT_NOPAGE;
}
folio_wait_writeback(folio);
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)
{
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fm->fc;
struct inode *inode = file_inode(file);
int rc;
/* DAX mmap is superior to direct_io mmap */
if (FUSE_IS_DAX(inode))
return fuse_dax_mmap(file, vma);
/*
* If inode is in passthrough io mode, because it has some file open
* in passthrough mode, either mmap to backing file or fail mmap,
* because mixing cached mmap and passthrough io mode is not allowed.
*/
if (fuse_file_passthrough(ff))
return fuse_passthrough_mmap(file, vma);
else if (fuse_inode_backing(get_fuse_inode(inode)))
return -ENODEV;
/*
* FOPEN_DIRECT_IO handling is special compared to O_DIRECT,
* as does not allow MAP_SHARED mmap without FUSE_DIRECT_IO_ALLOW_MMAP.
*/
if (ff->open_flags & FOPEN_DIRECT_IO) {
/*
* Can't provide the coherency needed for MAP_SHARED
* if FUSE_DIRECT_IO_ALLOW_MMAP isn't set.
*/
if ((vma->vm_flags & VM_MAYSHARE) && !fc->direct_io_allow_mmap)
return -ENODEV;
invalidate_inode_pages2(file->f_mapping);
if (!(vma->vm_flags & VM_MAYSHARE)) {
/* MAP_PRIVATE */
return generic_file_mmap(file, vma);
}
/*
* First mmap of direct_io file enters caching inode io mode.
* Also waits for parallel dio writers to go into serial mode
* (exclusive instead of shared lock).
* After first mmap, the inode stays in caching io mode until
* the direct_io file release.
*/
rc = fuse_file_cached_io_open(inode, ff);
if (rc)
return rc;
}
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 convert_fuse_file_lock(struct fuse_conn *fc,
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;
/*
* Convert pid into init's pid namespace. The locks API will
* translate it into the caller's pid namespace.
*/
rcu_read_lock();
fl->c.flc_pid = pid_nr_ns(find_pid_ns(ffl->pid, fc->pid_ns), &init_pid_ns);
rcu_read_unlock();
break;
default:
return -EIO;
}
fl->c.flc_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->c.flc_owner);
inarg->lk.start = fl->fl_start;
inarg->lk.end = fl->fl_end;
inarg->lk.type = fl->c.flc_type;
inarg->lk.pid = pid;
if (flock)
inarg->lk_flags |= FUSE_LK_FLOCK;
args->opcode = opcode;
args->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_mount *fm = get_fuse_mount(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(fm, &args);
if (!err)
err = convert_fuse_file_lock(fm->fc, &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_mount *fm = get_fuse_mount(inode);
FUSE_ARGS(args);
struct fuse_lk_in inarg;
int opcode = (fl->c.flc_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
struct pid *pid = fl->c.flc_type != F_UNLCK ? task_tgid(current) : NULL;
pid_t pid_nr = pid_nr_ns(pid, fm->fc->pid_ns);
int err;
if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
/* NLM needs asynchronous locks, which we don't support yet */
return -ENOLCK;
}
fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg);
err = fuse_simple_request(fm, &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_mount *fm = get_fuse_mount(inode);
FUSE_ARGS(args);
struct fuse_bmap_in inarg;
struct fuse_bmap_out outarg;
int err;
if (!inode->i_sb->s_bdev || fm->fc->no_bmap)
return 0;
memset(&inarg, 0, sizeof(inarg));
inarg.block = block;
inarg.blocksize = inode->i_sb->s_blocksize;
args.opcode = FUSE_BMAP;
args.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(fm, &args);
if (err == -ENOSYS)
fm->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_mount *fm = get_fuse_mount(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 (fm->fc->no_lseek)
goto fallback;
args.opcode = FUSE_LSEEK;
args.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(fm, &args);
if (err) {
if (err == -ENOSYS) {
fm->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, file, STATX_SIZE);
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, file, STATX_SIZE);
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;
}
/*
* 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, *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);
}
__poll_t fuse_file_poll(struct file *file, poll_table *wait)
{
struct fuse_file *ff = file->private_data;
struct fuse_mount *fm = ff->fm;
struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
struct fuse_poll_out outarg;
FUSE_ARGS(args);
int err;
if (fm->fc->no_poll)
return DEFAULT_POLLMASK;
poll_wait(file, &ff->poll_wait, wait);
inarg.events = mangle_poll(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(fm->fc, ff);
}
args.opcode = FUSE_POLL;
args.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(fm, &args);
if (!err)
return demangle_poll(outarg.revents);
if (err == -ENOSYS) {
fm->fc->no_poll = 1;
return DEFAULT_POLLMASK;
}
return EPOLLERR;
}
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(file_mnt_idmap(file), file_dentry(file), &attr, file);
}
static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off)
{
return round_up(off, fc->max_pages << PAGE_SHIFT);
}
static ssize_t
fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
DECLARE_COMPLETION_ONSTACK(wait);
ssize_t ret = 0;
struct file *file = iocb->ki_filp;
struct fuse_file *ff = file->private_data;
loff_t pos = 0;
struct inode *inode;
loff_t i_size;
size_t count = iov_iter_count(iter), shortened = 0;
loff_t offset = iocb->ki_pos;
struct fuse_io_priv *io;
pos = offset;
inode = file->f_mapping->host;
i_size = i_size_read(inode);
if ((iov_iter_rw(iter) == READ) && (offset >= i_size))
return 0;
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;
/*
* By default, we want to optimize all I/Os with async request
* submission to the client filesystem if supported.
*/
io->async = ff->fm->fc->async_dio;
io->iocb = iocb;
io->blocking = is_sync_kiocb(iocb);
/* optimization for short read */
if (io->async && !io->write && offset + count > i_size) {
iov_iter_truncate(iter, fuse_round_up(ff->fm->fc, i_size - offset));
shortened = count - iov_iter_count(iter);
count -= shortened;
}
/*
* We cannot asynchronously extend the size of a file.
* In such case the aio will behave exactly like sync io.
*/
if ((offset + count > i_size) && io->write)
io->blocking = true;
if (io->async && io->blocking) {
/*
* 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_mask(inode, FUSE_STATX_MODSIZE);
} else {
ret = __fuse_direct_read(io, iter, &pos);
}
iov_iter_reexpand(iter, iov_iter_count(iter) + shortened);
if (io->async) {
bool blocking = io->blocking;
fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
/* we have a non-extending, async request, so return */
if (!blocking)
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) {
fuse_write_update_attr(inode, pos, ret);
/* For extending writes we already hold exclusive lock */
if (ret < 0 && offset + count > i_size)
fuse_do_truncate(file);
}
return ret;
}
static int fuse_writeback_range(struct inode *inode, loff_t start, loff_t end)
{
int err = filemap_write_and_wait_range(inode->i_mapping, start, LLONG_MAX);
if (!err)
fuse_sync_writes(inode);
return err;
}
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_mount *fm = ff->fm;
FUSE_ARGS(args);
struct fuse_fallocate_in inarg = {
.fh = ff->fh,
.offset = offset,
.length = length,
.mode = mode
};
int err;
bool block_faults = FUSE_IS_DAX(inode) &&
(!(mode & FALLOC_FL_KEEP_SIZE) ||
(mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)));
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
FALLOC_FL_ZERO_RANGE))
return -EOPNOTSUPP;
if (fm->fc->no_fallocate)
return -EOPNOTSUPP;
inode_lock(inode);
if (block_faults) {
filemap_invalidate_lock(inode->i_mapping);
err = fuse_dax_break_layouts(inode, 0, -1);
if (err)
goto out;
}
if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) {
loff_t endbyte = offset + length - 1;
err = fuse_writeback_range(inode, offset, endbyte);
if (err)
goto out;
}
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
offset + length > i_size_read(inode)) {
err = inode_newsize_ok(inode, offset + length);
if (err)
goto out;
}
err = file_modified(file);
if (err)
goto out;
if (!(mode & FALLOC_FL_KEEP_SIZE))
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
args.opcode = FUSE_FALLOCATE;
args.nodeid = ff->nodeid;
args.in_numargs = 1;
args.in_args[0].size = sizeof(inarg);
args.in_args[0].value = &inarg;
err = fuse_simple_request(fm, &args);
if (err == -ENOSYS) {
fm->fc->no_fallocate = 1;
err = -EOPNOTSUPP;
}
if (err)
goto out;
/* we could have extended the file */
if (!(mode & FALLOC_FL_KEEP_SIZE)) {
if (fuse_write_update_attr(inode, offset + length, length))
file_update_time(file);
}
if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
truncate_pagecache_range(inode, offset, offset + length - 1);
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
out:
if (!(mode & FALLOC_FL_KEEP_SIZE))
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
if (block_faults)
filemap_invalidate_unlock(inode->i_mapping);
inode_unlock(inode);
fuse_flush_time_update(inode);
return err;
}
static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t len, unsigned int flags)
{
struct fuse_file *ff_in = file_in->private_data;
struct fuse_file *ff_out = file_out->private_data;
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
struct fuse_inode *fi_out = get_fuse_inode(inode_out);
struct fuse_mount *fm = ff_in->fm;
struct fuse_conn *fc = fm->fc;
FUSE_ARGS(args);
struct fuse_copy_file_range_in inarg = {
.fh_in = ff_in->fh,
.off_in = pos_in,
.nodeid_out = ff_out->nodeid,
.fh_out = ff_out->fh,
.off_out = pos_out,
.len = len,
.flags = flags
};
struct fuse_write_out outarg;
struct fuse_copy_file_range_out outarg_64;
u64 bytes_copied;
ssize_t err;
/* mark unstable when write-back is not used, and file_out gets
* extended */
bool is_unstable = (!fc->writeback_cache) &&
((pos_out + len) > inode_out->i_size);
if (fc->no_copy_file_range)
return -EOPNOTSUPP;
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
return -EXDEV;
inode_lock(inode_in);
err = fuse_writeback_range(inode_in, pos_in, pos_in + len - 1);
inode_unlock(inode_in);
if (err)
return err;
inode_lock(inode_out);
err = file_modified(file_out);
if (err)
goto out;
/*
* Write out dirty pages in the destination file before sending the COPY
* request to userspace. After the request is completed, truncate off
* pages (including partial ones) from the cache that have been copied,
* since these contain stale data at that point.
*
* This should be mostly correct, but if the COPY writes to partial
* pages (at the start or end) and the parts not covered by the COPY are
* written through a memory map after calling fuse_writeback_range(),
* then these partial page modifications will be lost on truncation.
*
* It is unlikely that someone would rely on such mixed style
* modifications. Yet this does give less guarantees than if the
* copying was performed with write(2).
*
* To fix this a mapping->invalidate_lock could be used to prevent new
* faults while the copy is ongoing.
*/
err = fuse_writeback_range(inode_out, pos_out, pos_out + len - 1);
if (err)
goto out;
if (is_unstable)
set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
args.opcode = FUSE_COPY_FILE_RANGE_64;
args.nodeid = ff_in->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_64);
args.out_args[0].value = &outarg_64;
if (fc->no_copy_file_range_64) {
fallback:
/* Fall back to old op that can't handle large copy length */
args.opcode = FUSE_COPY_FILE_RANGE;
args.out_args[0].size = sizeof(outarg);
args.out_args[0].value = &outarg;
inarg.len = len = min_t(size_t, len, UINT_MAX & PAGE_MASK);
}
err = fuse_simple_request(fm, &args);
if (err == -ENOSYS) {
if (fc->no_copy_file_range_64) {
fc->no_copy_file_range = 1;
err = -EOPNOTSUPP;
} else {
fc->no_copy_file_range_64 = 1;
goto fallback;
}
}
if (err)
goto out;
bytes_copied = fc->no_copy_file_range_64 ?
outarg.size : outarg_64.bytes_copied;
if (bytes_copied > len) {
err = -EIO;
goto out;
}
truncate_inode_pages_range(inode_out->i_mapping,
ALIGN_DOWN(pos_out, PAGE_SIZE),
ALIGN(pos_out + bytes_copied, PAGE_SIZE) - 1);
file_update_time(file_out);
fuse_write_update_attr(inode_out, pos_out + bytes_copied, bytes_copied);
err = bytes_copied;
out:
if (is_unstable)
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
inode_unlock(inode_out);
file_accessed(file_in);
fuse_flush_time_update(inode_out);
return err;
}
static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off,
struct file *dst_file, loff_t dst_off,
size_t len, unsigned int flags)
{
ssize_t ret;
ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
len, flags);
if (ret == -EOPNOTSUPP || ret == -EXDEV)
ret = splice_copy_file_range(src_file, src_off, dst_file,
dst_off, len);
return ret;
}
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,
.get_unmapped_area = thp_get_unmapped_area,
.flock = fuse_file_flock,
.splice_read = fuse_splice_read,
.splice_write = fuse_splice_write,
.unlocked_ioctl = fuse_file_ioctl,
.compat_ioctl = fuse_file_compat_ioctl,
.poll = fuse_file_poll,
.fallocate = fuse_file_fallocate,
.copy_file_range = fuse_copy_file_range,
};
static const struct address_space_operations fuse_file_aops = {
.read_folio = fuse_read_folio,
.readahead = fuse_readahead,
.writepages = fuse_writepages,
.launder_folio = fuse_launder_folio,
.dirty_folio = iomap_dirty_folio,
.release_folio = iomap_release_folio,
.invalidate_folio = iomap_invalidate_folio,
.is_partially_uptodate = iomap_is_partially_uptodate,
.migrate_folio = filemap_migrate_folio,
.bmap = fuse_bmap,
.direct_IO = fuse_direct_IO,
};
void fuse_init_file_inode(struct inode *inode, unsigned int flags)
{
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
inode->i_fop = &fuse_file_operations;
inode->i_data.a_ops = &fuse_file_aops;
if (fc->writeback_cache)
mapping_set_writeback_may_deadlock_on_reclaim(&inode->i_data);
INIT_LIST_HEAD(&fi->write_files);
INIT_LIST_HEAD(&fi->queued_writes);
fi->writectr = 0;
fi->iocachectr = 0;
init_waitqueue_head(&fi->page_waitq);
init_waitqueue_head(&fi->direct_io_waitq);
if (IS_ENABLED(CONFIG_FUSE_DAX))
fuse_dax_inode_init(inode, flags);
}