linux-kernel - [PATCH 13/16] Unionfs: support splice(2)

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: <1196095458112-git-send-email-ezk@cs.sunysb.edu>
Date:	Mon, 26 Nov 2007 11:44:10 -0500
From:	Erez Zadok <ezk@...sunysb.edu>
To:	akpm@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	viro@....linux.org.uk, hch@...radead.org,
	Erez Zadok <ezk@...sunysb.edu>
Subject: [PATCH 13/16] Unionfs: support splice(2)

Also remove redundant variable from unionfs_readpage (saves a bit on stack
space).

Signed-off-by: Erez Zadok <ezk@...sunysb.edu>
---
 fs/unionfs/file.c |    1 +
 fs/unionfs/mmap.c |   10 ++++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c
index cfbfb8e..b7d0d55 100644
--- a/fs/unionfs/file.c
+++ b/fs/unionfs/file.c
@@ -246,4 +246,5 @@ struct file_operations unionfs_main_fops = {
 	.fsync		= unionfs_fsync,
 	.fasync		= unionfs_fasync,
 	.splice_read	= generic_file_splice_read,
+	.splice_write	= generic_file_splice_write,
 };
diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c
index fa358ef..623a913 100644
--- a/fs/unionfs/mmap.c
+++ b/fs/unionfs/mmap.c
@@ -147,7 +147,7 @@ static int unionfs_readpage(struct file *file, struct page *page)
 	struct inode *inode;
 	mm_segment_t old_fs;
 	char *page_data = NULL;
-	loff_t offset;
+	mode_t orig_mode;
 
 	unionfs_read_lock(file->f_path.dentry->d_sb);
 	err = unionfs_file_revalidate(file, false);
@@ -175,11 +175,17 @@ static int unionfs_readpage(struct file *file, struct page *page)
 	 * the necessary magic for us.
 	 */
 	lower_file->f_pos = page_offset(page);
-	offset = page_offset(page);
 	old_fs = get_fs();
 	set_fs(KERNEL_DS);
+	/*
+	 * generic_file_splice_write may call us on a file not opened for
+	 * reading, so temporarily allow reading.
+	 */
+	orig_mode = lower_file->f_mode;
+	lower_file->f_mode |= FMODE_READ;
 	err = vfs_read(lower_file, page_data, PAGE_CACHE_SIZE,
 		       &lower_file->f_pos);
+	lower_file->f_mode = orig_mode;
 	set_fs(old_fs);
 	if (err >= 0 && err < PAGE_CACHE_SIZE)
 		memset(page_data + err, 0, PAGE_CACHE_SIZE - err);
-- 
1.5.2.2

-
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/