From 88b88a66797159949cec32eaab12b4968f6fae2d Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Mon, 6 Oct 2014 17:39:50 -0700 Subject: f2fs: support atomic writes This patch introduces a very limited functionality for atomic write support. In order to support atomic write, this patch adds two ioctls: o F2FS_IOC_START_ATOMIC_WRITE o F2FS_IOC_COMMIT_ATOMIC_WRITE The database engine should be aware of the following sequence. 1. open -> ioctl(F2FS_IOC_START_ATOMIC_WRITE); 2. writes : all the written data will be treated as atomic pages. 3. commit -> ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE); : this flushes all the data blocks to the disk, which will be shown all or nothing by f2fs recovery procedure. 4. repeat to #2. The IO pattens should be: ,- START_ATOMIC_WRITE ,- COMMIT_ATOMIC_WRITE CP | D D D D D D | FSYNC | D D D D | FSYNC ... `- COMMIT_ATOMIC_WRITE Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/f2fs/data.c') diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 13ab72084913..8bbd60633f37 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1052,7 +1052,10 @@ static int f2fs_write_end(struct file *file, trace_f2fs_write_end(inode, pos, len, copied); - set_page_dirty(page); + if (f2fs_is_atomic_file(inode)) + register_inmem_page(inode, page); + else + set_page_dirty(page); if (pos + copied > i_size_read(inode)) { i_size_write(inode, pos + copied); -- cgit v1.2.3