linux-kernel - [PATCH 04/14] fuse: Prepare to handle multiple pages in writeback

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20121116170703.3196.77938.stgit@maximpc.sw.ru>
Date:	Fri, 16 Nov 2012 21:07:10 +0400
From:	Maxim Patlasov <mpatlasov@...allels.com>
To:	miklos@...redi.hu
Cc:	dev@...allels.com, fuse-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org, jbottomley@...allels.com,
	viro@...iv.linux.org.uk, linux-fsdevel@...r.kernel.org,
	xemul@...nvz.org
Subject: [PATCH 04/14] fuse: Prepare to handle multiple pages in writeback

The .writepages callback will issue writeback requests with more than one
page aboard. Make existing end/check code be aware of this.

Original patch by: Pavel Emelyanov <xemul@...nvz.org>
Signed-off-by: Maxim Patlasov <MPatlasov@...allels.com>
---
 fs/fuse/file.c |   22 +++++++++++++++-------
 1 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 51804cf..0cc62f59 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -345,7 +345,8 @@ 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;
 		}
@@ -1196,7 +1197,10 @@ 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]);
 	fuse_file_put(req->ff, false);
 }
 
@@ -1205,10 +1209,13 @@ 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);
-	dec_bdi_stat(bdi, BDI_WRITEBACK);
-	dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
+	for (i = 0; i < req->num_pages; i++) {
+		dec_bdi_stat(bdi, BDI_WRITEBACK);
+		dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
+	}
 	bdi_writeout_inc(bdi);
 	wake_up(&fi->page_waitq);
 }
@@ -1221,14 +1228,15 @@ __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;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/