Commit 003386ff authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  mm: export generic_pipe_buf_*() to modules
  fuse: support splice() reading from fuse device
  fuse: allow splice to move pages
  mm: export remove_from_page_cache() to modules
  mm: export lru_cache_add_*() to modules
  fuse: support splice() writing to fuse device
  fuse: get page reference for readpages
  fuse: use get_user_pages_fast()
  fuse: remove unneeded variable
parents 092405cd 51921cb7
......@@ -16,6 +16,9 @@
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/pipe_fs_i.h>
#include <linux/swap.h>
#include <linux/splice.h>
MODULE_ALIAS_MISCDEV(FUSE_MINOR);
MODULE_ALIAS("devname:fuse");
......@@ -499,6 +502,9 @@ struct fuse_copy_state {
int write;
struct fuse_req *req;
const struct iovec *iov;
struct pipe_buffer *pipebufs;
struct pipe_buffer *currbuf;
struct pipe_inode_info *pipe;
unsigned long nr_segs;
unsigned long seglen;
unsigned long addr;
......@@ -506,16 +512,16 @@ struct fuse_copy_state {
void *mapaddr;
void *buf;
unsigned len;
unsigned move_pages:1;
};
static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
int write, struct fuse_req *req,
int write,
const struct iovec *iov, unsigned long nr_segs)
{
memset(cs, 0, sizeof(*cs));
cs->fc = fc;
cs->write = write;
cs->req = req;
cs->iov = iov;
cs->nr_segs = nr_segs;
}
......@@ -523,7 +529,18 @@ static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
/* Unmap and put previous page of userspace buffer */
static void fuse_copy_finish(struct fuse_copy_state *cs)
{
if (cs->mapaddr) {
if (cs->currbuf) {
struct pipe_buffer *buf = cs->currbuf;
if (!cs->write) {
buf->ops->unmap(cs->pipe, buf, cs->mapaddr);
} else {
kunmap_atomic(cs->mapaddr, KM_USER0);
buf->len = PAGE_SIZE - cs->len;
}
cs->currbuf = NULL;
cs->mapaddr = NULL;
} else if (cs->mapaddr) {
kunmap_atomic(cs->mapaddr, KM_USER0);
if (cs->write) {
flush_dcache_page(cs->pg);
......@@ -545,26 +562,61 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
unlock_request(cs->fc, cs->req);
fuse_copy_finish(cs);
if (!cs->seglen) {
BUG_ON(!cs->nr_segs);
cs->seglen = cs->iov[0].iov_len;
cs->addr = (unsigned long) cs->iov[0].iov_base;
cs->iov++;
cs->nr_segs--;
if (cs->pipebufs) {
struct pipe_buffer *buf = cs->pipebufs;
if (!cs->write) {
err = buf->ops->confirm(cs->pipe, buf);
if (err)
return err;
BUG_ON(!cs->nr_segs);
cs->currbuf = buf;
cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
cs->len = buf->len;
cs->buf = cs->mapaddr + buf->offset;
cs->pipebufs++;
cs->nr_segs--;
} else {
struct page *page;
if (cs->nr_segs == cs->pipe->buffers)
return -EIO;
page = alloc_page(GFP_HIGHUSER);
if (!page)
return -ENOMEM;
buf->page = page;
buf->offset = 0;
buf->len = 0;
cs->currbuf = buf;
cs->mapaddr = kmap_atomic(page, KM_USER0);
cs->buf = cs->mapaddr;
cs->len = PAGE_SIZE;
cs->pipebufs++;
cs->nr_segs++;
}
} else {
if (!cs->seglen) {
BUG_ON(!cs->nr_segs);
cs->seglen = cs->iov[0].iov_len;
cs->addr = (unsigned long) cs->iov[0].iov_base;
cs->iov++;
cs->nr_segs--;
}
err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
if (err < 0)
return err;
BUG_ON(err != 1);
offset = cs->addr % PAGE_SIZE;
cs->mapaddr = kmap_atomic(cs->pg, KM_USER0);
cs->buf = cs->mapaddr + offset;
cs->len = min(PAGE_SIZE - offset, cs->seglen);
cs->seglen -= cs->len;
cs->addr += cs->len;
}
down_read(&current->mm->mmap_sem);
err = get_user_pages(current, current->mm, cs->addr, 1, cs->write, 0,
&cs->pg, NULL);
up_read(&current->mm->mmap_sem);
if (err < 0)
return err;
BUG_ON(err != 1);
offset = cs->addr % PAGE_SIZE;
cs->mapaddr = kmap_atomic(cs->pg, KM_USER0);
cs->buf = cs->mapaddr + offset;
cs->len = min(PAGE_SIZE - offset, cs->seglen);
cs->seglen -= cs->len;
cs->addr += cs->len;
return lock_request(cs->fc, cs->req);
}
......@@ -586,23 +638,178 @@ static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
return ncpy;
}
static int fuse_check_page(struct page *page)
{
if (page_mapcount(page) ||
page->mapping != NULL ||
page_count(page) != 1 ||
(page->flags & PAGE_FLAGS_CHECK_AT_PREP &
~(1 << PG_locked |
1 << PG_referenced |
1 << PG_uptodate |
1 << PG_lru |
1 << PG_active |
1 << PG_reclaim))) {
printk(KERN_WARNING "fuse: trying to steal weird page\n");
printk(KERN_WARNING " page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
return 1;
}
return 0;
}
static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
{
int err;
struct page *oldpage = *pagep;
struct page *newpage;
struct pipe_buffer *buf = cs->pipebufs;
struct address_space *mapping;
pgoff_t index;
unlock_request(cs->fc, cs->req);
fuse_copy_finish(cs);
err = buf->ops->confirm(cs->pipe, buf);
if (err)
return err;
BUG_ON(!cs->nr_segs);
cs->currbuf = buf;
cs->len = buf->len;
cs->pipebufs++;
cs->nr_segs--;
if (cs->len != PAGE_SIZE)
goto out_fallback;
if (buf->ops->steal(cs->pipe, buf) != 0)
goto out_fallback;
newpage = buf->page;
if (WARN_ON(!PageUptodate(newpage)))
return -EIO;
ClearPageMappedToDisk(newpage);
if (fuse_check_page(newpage) != 0)
goto out_fallback_unlock;
mapping = oldpage->mapping;
index = oldpage->index;
/*
* This is a new and locked page, it shouldn't be mapped or
* have any special flags on it
*/
if (WARN_ON(page_mapped(oldpage)))
goto out_fallback_unlock;
if (WARN_ON(page_has_private(oldpage)))
goto out_fallback_unlock;
if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
goto out_fallback_unlock;
if (WARN_ON(PageMlocked(oldpage)))
goto out_fallback_unlock;
remove_from_page_cache(oldpage);
page_cache_release(oldpage);
err = add_to_page_cache_locked(newpage, mapping, index, GFP_KERNEL);
if (err) {
printk(KERN_WARNING "fuse_try_move_page: failed to add page");
goto out_fallback_unlock;
}
page_cache_get(newpage);
if (!(buf->flags & PIPE_BUF_FLAG_LRU))
lru_cache_add_file(newpage);
err = 0;
spin_lock(&cs->fc->lock);
if (cs->req->aborted)
err = -ENOENT;
else
*pagep = newpage;
spin_unlock(&cs->fc->lock);
if (err) {
unlock_page(newpage);
page_cache_release(newpage);
return err;
}
unlock_page(oldpage);
page_cache_release(oldpage);
cs->len = 0;
return 0;
out_fallback_unlock:
unlock_page(newpage);
out_fallback:
cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
cs->buf = cs->mapaddr + buf->offset;
err = lock_request(cs->fc, cs->req);
if (err)
return err;
return 1;
}
static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
unsigned offset, unsigned count)
{
struct pipe_buffer *buf;
if (cs->nr_segs == cs->pipe->buffers)
return -EIO;
unlock_request(cs->fc, cs->req);
fuse_copy_finish(cs);
buf = cs->pipebufs;
page_cache_get(page);
buf->page = page;
buf->offset = offset;
buf->len = count;
cs->pipebufs++;
cs->nr_segs++;
cs->len = 0;
return 0;
}
/*
* Copy a page in the request to/from the userspace buffer. Must be
* done atomically
*/
static int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
unsigned offset, unsigned count, int zeroing)
{
int err;
struct page *page = *pagep;
if (page && zeroing && count < PAGE_SIZE) {
void *mapaddr = kmap_atomic(page, KM_USER1);
memset(mapaddr, 0, PAGE_SIZE);
kunmap_atomic(mapaddr, KM_USER1);
}
while (count) {
if (!cs->len) {
int err = fuse_copy_fill(cs);
if (err)
return err;
if (cs->write && cs->pipebufs && page) {
return fuse_ref_page(cs, page, offset, count);
} else if (!cs->len) {
if (cs->move_pages && page &&
offset == 0 && count == PAGE_SIZE) {
err = fuse_try_move_page(cs, pagep);
if (err <= 0)
return err;
} else {
err = fuse_copy_fill(cs);
if (err)
return err;
}
}
if (page) {
void *mapaddr = kmap_atomic(page, KM_USER1);
......@@ -627,8 +834,10 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);
for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
struct page *page = req->pages[i];
int err = fuse_copy_page(cs, page, offset, count, zeroing);
int err;
err = fuse_copy_page(cs, &req->pages[i], offset, count,
zeroing);
if (err)
return err;
......@@ -705,11 +914,10 @@ __acquires(&fc->lock)
*
* Called with fc->lock held, releases it
*/
static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_req *req,
const struct iovec *iov, unsigned long nr_segs)
static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
size_t nbytes, struct fuse_req *req)
__releases(&fc->lock)
{
struct fuse_copy_state cs;
struct fuse_in_header ih;
struct fuse_interrupt_in arg;
unsigned reqsize = sizeof(ih) + sizeof(arg);
......@@ -725,14 +933,13 @@ __releases(&fc->lock)
arg.unique = req->in.h.unique;
spin_unlock(&fc->lock);
if (iov_length(iov, nr_segs) < reqsize)
if (nbytes < reqsize)
return -EINVAL;
fuse_copy_init(&cs, fc, 1, NULL, iov, nr_segs);
err = fuse_copy_one(&cs, &ih, sizeof(ih));
err = fuse_copy_one(cs, &ih, sizeof(ih));
if (!err)
err = fuse_copy_one(&cs, &arg, sizeof(arg));
fuse_copy_finish(&cs);
err = fuse_copy_one(cs, &arg, sizeof(arg));
fuse_copy_finish(cs);
return err ? err : reqsize;
}
......@@ -746,18 +953,13 @@ __releases(&fc->lock)
* request_end(). Otherwise add it to the processing list, and set
* the 'sent' flag.
*/
static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
struct fuse_copy_state *cs, size_t nbytes)
{
int err;
struct fuse_req *req;
struct fuse_in *in;
struct fuse_copy_state cs;
unsigned reqsize;
struct file *file = iocb->ki_filp;
struct fuse_conn *fc = fuse_get_conn(file);
if (!fc)
return -EPERM;
restart:
spin_lock(&fc->lock);
......@@ -777,7 +979,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
if (!list_empty(&fc->interrupts)) {
req = list_entry(fc->interrupts.next, struct fuse_req,
intr_entry);
return fuse_read_interrupt(fc, req, iov, nr_segs);
return fuse_read_interrupt(fc, cs, nbytes, req);
}
req = list_entry(fc->pending.next, struct fuse_req, list);
......@@ -787,7 +989,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
in = &req->in;
reqsize = in->h.len;
/* If request is too large, reply with an error and restart the read */
if (iov_length(iov, nr_segs) < reqsize) {
if (nbytes < reqsize) {
req->out.h.error = -EIO;
/* SETXATTR is special, since it may contain too large data */
if (in->h.opcode == FUSE_SETXATTR)
......@@ -796,12 +998,12 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
goto restart;
}
spin_unlock(&fc->lock);
fuse_copy_init(&cs, fc, 1, req, iov, nr_segs);
err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
cs->req = req;
err = fuse_copy_one(cs, &in->h, sizeof(in->h));
if (!err)
err = fuse_copy_args(&cs, in->numargs, in->argpages,
err = fuse_copy_args(cs, in->numargs, in->argpages,
(struct fuse_arg *) in->args, 0);
fuse_copy_finish(&cs);
fuse_copy_finish(cs);
spin_lock(&fc->lock);
req->locked = 0;
if (req->aborted) {
......@@ -829,6 +1031,110 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
return err;
}
static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct fuse_copy_state cs;
struct file *file = iocb->ki_filp;
struct fuse_conn *fc = fuse_get_conn(file);
if (!fc)
return -EPERM;
fuse_copy_init(&cs, fc, 1, iov, nr_segs);
return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
}
static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
return 1;
}
static const struct pipe_buf_operations fuse_dev_pipe_buf_ops = {
.can_merge = 0,
.map = generic_pipe_buf_map,
.unmap = generic_pipe_buf_unmap,
.confirm = generic_pipe_buf_confirm,
.release = generic_pipe_buf_release,
.steal = fuse_dev_pipe_buf_steal,
.get = generic_pipe_buf_get,
};
static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags)
{
int ret;
int page_nr = 0;
int do_wakeup = 0;
struct pipe_buffer *bufs;
struct fuse_copy_state cs;
struct fuse_conn *fc = fuse_get_conn(in);
if (!fc)
return -EPERM;
bufs = kmalloc(pipe->buffers * sizeof (struct pipe_buffer), GFP_KERNEL);
if (!bufs)
return -ENOMEM;
fuse_copy_init(&cs, fc, 1, NULL, 0);
cs.pipebufs = bufs;
cs.pipe = pipe;
ret = fuse_dev_do_read(fc, in, &cs, len);
if (ret < 0)
goto out;
ret = 0;
pipe_lock(pipe);
if (!pipe->readers) {
send_sig(SIGPIPE, current, 0);
if (!ret)
ret = -EPIPE;
goto out_unlock;
}
if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
ret = -EIO;
goto out_unlock;
}
while (page_nr < cs.nr_segs) {
int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
struct pipe_buffer *buf = pipe->bufs + newbuf;
buf->page = bufs[page_nr].page;
buf->offset = bufs[page_nr].offset;
buf->len = bufs[page_nr].len;
buf->ops = &fuse_dev_pipe_buf_ops;
pipe->nrbufs++;
page_nr++;
ret += buf->len;
if (pipe->inode)
do_wakeup = 1;
}
out_unlock:
pipe_unlock(pipe);
if (do_wakeup) {
smp_mb();
if (waitqueue_active(&pipe->wait))
wake_up_interruptible(&pipe->wait);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
}
out:
for (; page_nr < cs.nr_segs; page_nr++)
page_cache_release(bufs[page_nr].page);
kfree(bufs);
return ret;
}
static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
struct fuse_copy_state *cs)
{
......@@ -988,23 +1294,17 @@ static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
* it from the list and copy the rest of the buffer to the request.
* The request is finished by calling request_end()
*/
static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
struct fuse_copy_state *cs, size_t nbytes)
{
int err;
size_t nbytes = iov_length(iov, nr_segs);
struct fuse_req *req;
struct fuse_out_header oh;
struct fuse_copy_state cs;
struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
if (!fc)
return -EPERM;
fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
if (nbytes < sizeof(struct fuse_out_header))
return -EINVAL;
err = fuse_copy_one(&cs, &oh, sizeof(oh));
err = fuse_copy_one(cs, &oh, sizeof(oh));
if (err)
goto err_finish;
......@@ -1017,7 +1317,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
* and error contains notification code.
*/
if (!oh.unique) {
err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), &cs);
err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
return err ? err : nbytes;
}
......@@ -1036,7 +1336,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
if (req->aborted) {
spin_unlock(&fc->lock);
fuse_copy_finish(&cs);
fuse_copy_finish(cs);
spin_lock(&fc->lock);
request_end(fc, req);
return -ENOENT;
......@@ -1053,7 +1353,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
queue_interrupt(fc, req);
spin_unlock(&fc->lock);
fuse_copy_finish(&cs);
fuse_copy_finish(cs);
return nbytes;
}
......@@ -1061,11 +1361,13 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
list_move(&req->list, &fc->io);
req->out.h = oh;
req->locked = 1;
cs.req = req;
cs->req = req;
if (!req->out.page_replace)
cs->move_pages = 0;
spin_unlock(&fc->lock);
err = copy_out_args(&cs, &req->out, nbytes);
fuse_copy_finish(&cs);
err = copy_out_args(cs, &req->out, nbytes);
fuse_copy_finish(cs);
spin_lock(&fc->lock);
req->locked = 0;
......@@ -1081,10 +1383,101 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
err_unlock:
spin_unlock(&fc->lock);
err_finish:
fuse_copy_finish(&cs);
fuse_copy_finish(cs);
return err;
}
static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct fuse_copy_state cs;
struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
if (!fc)
return -EPERM;
fuse_copy_init(&cs, fc, 0, iov, nr_segs);
return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
}
static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
struct file *out, loff_t *ppos,