Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse (a7fa20a5) · Commits · 戴 / test

Documentation/devices.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -414,6 +414,7 @@ Your cooperation is appreciated.
		200 = /dev/net/tun TAP/TUN network device
		201 = /dev/button/gulpb Transmeta GULP-B buttons
		202 = /dev/emd/ctl Enhanced Metadisk RAID (EMD) control
		203 = /dev/cuse Cuse (character device in user-space)
		204 = /dev/video/em8300 EM8300 DVD decoder control
		205 = /dev/video/em8300_mv EM8300 DVD decoder video
		206 = /dev/video/em8300_ma EM8300 DVD decoder audio

fs/fuse/cuse.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -589,11 +589,14 @@ static struct attribute *cuse_class_dev_attrs[] = {
		ATTRIBUTE_GROUPS(cuse_class_dev);

		static struct miscdevice cuse_miscdev = {
		.minor = MISC_DYNAMIC_MINOR,
		.minor = CUSE_MINOR,
		.name = "cuse",
		.fops = &cuse_channel_fops,
		};

		MODULE_ALIAS_MISCDEV(CUSE_MINOR);
		MODULE_ALIAS("devname:cuse");

		static int __init cuse_init(void)
		{
		int i, rc;

fs/fuse/file.c

+335 −26

Original line number	Diff line number	Diff line
		@@ -334,7 +334,8 @@ static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)

		BUG_ON(req->inode != inode);
		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
		if (curr_index == index) {
		if (curr_index <= index &&
		index < curr_index + req->num_pages) {
		found = true;
		break;
		}
		@@ -1409,7 +1410,12 @@ static ssize_t fuse_direct_write(struct file file, const char __user buf,

		static void fuse_writepage_free(struct fuse_conn fc, struct fuse_req req)
		{
		__free_page(req->pages[0]);
		int i;

		for (i = 0; i < req->num_pages; i++)
		__free_page(req->pages[i]);

		if (req->ff)
		fuse_file_put(req->ff, false);
		}

		@@ -1418,30 +1424,34 @@ static void fuse_writepage_finish(struct fuse_conn fc, struct fuse_req req)
		struct inode *inode = req->inode;
		struct fuse_inode *fi = get_fuse_inode(inode);
		struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
		int i;

		list_del(&req->writepages_entry);
		for (i = 0; i < req->num_pages; i++) {
		dec_bdi_stat(bdi, BDI_WRITEBACK);
		dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
		dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
		bdi_writeout_inc(bdi);
		}
		wake_up(&fi->page_waitq);
		}

		/* Called under fc->lock, may release and reacquire it */
		static void fuse_send_writepage(struct fuse_conn fc, struct fuse_req req)
		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);
		loff_t size = i_size_read(req->inode);
		struct fuse_write_in *inarg = &req->misc.write.in;
		__u64 data_size = req->num_pages * PAGE_CACHE_SIZE;

		if (!fc->connected)
		goto out_free;

		if (inarg->offset + PAGE_CACHE_SIZE <= size) {
		inarg->size = PAGE_CACHE_SIZE;
		if (inarg->offset + data_size <= size) {
		inarg->size = data_size;
		} else if (inarg->offset < size) {
		inarg->size = size & (PAGE_CACHE_SIZE - 1);
		inarg->size = size - inarg->offset;
		} else {
		/* Got truncated off completely */
		goto out_free;
		@@ -1472,12 +1482,13 @@ __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);
		fuse_send_writepage(fc, req, crop);
		}
		}

		@@ -1488,12 +1499,62 @@ static void fuse_writepage_end(struct fuse_conn fc, struct fuse_req req)

		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 (!WARN_ON(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 int fuse_writepage_locked(struct page *page)
		{
		struct address_space *mapping = page->mapping;
		@@ -1501,8 +1562,8 @@ static int fuse_writepage_locked(struct page *page)
		struct fuse_conn *fc = get_fuse_conn(inode);
		struct fuse_inode *fi = get_fuse_inode(inode);
		struct fuse_req *req;
		struct fuse_file *ff;
		struct page *tmp_page;
		int error = -ENOMEM;

		set_page_writeback(page);

		@@ -1515,16 +1576,16 @@ static int fuse_writepage_locked(struct page *page)
		if (!tmp_page)
		goto err_free;

		spin_lock(&fc->lock);
		BUG_ON(list_empty(&fi->write_files));
		ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
		req->ff = fuse_file_get(ff);
		spin_unlock(&fc->lock);
		error = -EIO;
		req->ff = fuse_write_file_get(fc, fi);
		if (!req->ff)
		goto err_free;

		fuse_write_fill(req, ff, page_offset(page), 0);
		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;
		@@ -1550,19 +1611,263 @@ err_free:
		fuse_request_free(req);
		err:
		end_page_writeback(page);
		return -ENOMEM;
		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_CACHE_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_CACHE_SHIFT;
		if (tmp->num_pages == 1 &&
		curr_index == page->index) {
		old_req = tmp;
		}
		}

		if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT \|\|
		old_req->state == FUSE_REQ_PENDING)) {
		struct backing_dev_info *bdi = page->mapping->backing_dev_info;

		copy_highpage(old_req->pages[0], page);
		spin_unlock(&fc->lock);

		dec_bdi_stat(bdi, BDI_WRITEBACK);
		dec_zone_page_state(page, NR_WRITEBACK_TEMP);
		bdi_writeout_inc(bdi);
		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_CACHE_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;
		req->background = 1;
		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_bdi_stat(page->mapping->backing_dev_info, BDI_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 = kzalloc(sizeof(struct page )
		FUSE_MAX_PAGES_PER_REQ,
		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;
		}

		static int fuse_launder_page(struct page *page)
		{
		int err = 0;
		@@ -1602,14 +1907,17 @@ static void fuse_vma_close(struct vm_area_struct *vma)
		static int fuse_page_mkwrite(struct vm_area_struct vma, struct vm_fault vmf)
		{
		struct page *page = vmf->page;
		/*
		* Don't use page->mapping as it may become NULL from a
		* concurrent truncate.
		*/
		struct inode *inode = vma->vm_file->f_mapping->host;
		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 0;
		return VM_FAULT_LOCKED;
		}

		static const struct vm_operations_struct fuse_file_vm_ops = {
		@@ -2581,6 +2889,7 @@ static const struct file_operations fuse_direct_io_file_operations = {
		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,

fs/fuse/fuse_i.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -321,6 +321,7 @@ struct fuse_req {
		struct {
		struct fuse_write_in in;
		struct fuse_write_out out;
		struct fuse_req *next;
		} write;
		struct fuse_notify_retrieve_in retrieve_in;
		struct fuse_lk_in lk_in;

include/linux/miscdevice.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@
		#define I2O_MINOR 166
		#define MICROCODE_MINOR 184
		#define TUN_MINOR 200
		#define CUSE_MINOR 203
		#define MWAVE_MINOR 219 /* ACP/Mwave Modem */
		#define MPT_MINOR 220
		#define MPT2SAS_MINOR 221

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