[PATCH 03/16] vfs: Remove syncing from generic_file_direct_write() and generic_file_buffered_write()

Jan Kara
2009-09-02T13:59:38Z

generic_file_direct_write() and generic_file_buffered_write() called
generic_osync_inode() if it was called on O_SYNC file or IS_SYNC inode. But
this is superfluous since generic_file_aio_write() does the syncing as well.
Also XFS and OCFS2 which call these functions directly handle syncing
themselves. So let's have a single place where syncing happens:
generic_file_aio_write().

We slightly change the behavior by syncing only the range of file to which the
write happened for buffered writes but that should be all that is required.

CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker <joel.becker@oracle.com>
CC: Felix Blyakher <felixb@sgi.com>
CC: xfs@oss.sgi.com
Signed-off-by: Jan Kara <jack@suse.cz>
---
mm/filemap.c | 35 ++++++-----------------------------
1 files changed, 6 insertions(+), 29 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 554a396..f863e1d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2187,20 +2187,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
}
*ppos = end;
}
-
- /*
- * Sync the fs metadata but not the minor inode changes and
- * of course not the data as we did direct DMA for the IO.
- * i_mutex is held, which protects generic_osync_inode() from
- * livelocking. AIO O_DIRECT ops attempt to sync metadata here.
- */
out:
- if ((written >= 0 || written == -EIOCBQUEUED) &&
- ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
- if (err < 0)
- written = err;
- }
return written;
}
EXPORT_SYMBOL(generic_file_direct_write);
@@ -2332,8 +2319,6 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
- const struct address_space_operations *a_ops = mapping->a_ops;
- struct inode *inode = mapping->host;
ssize_t status;
struct iov_iter i;

@@ -2343,16 +2328,6 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
if (likely(status >= 0)) {
written += status;
*ppos = pos + status;
-
- /*
- * For now, when the user asks for O_SYNC, we'll actually give
- * O_DSYNC
- */
- if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- if (!a_ops->writepage || !is_sync_kiocb(iocb))
- status = generic_osync_inode(inode, mapping,
- OSYNC_METADATA|OSYNC_DATA);
- }
}

/*
@@ -2514,11 +2489,12 @@ ssize_t generic_file_aio_write_nolock(struct kiocb *iocb,

ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);

- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ if ((ret > 0 || ret == -EIOCBQUEUED) &&
+ ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;

err = sync_page_range_nolock(inode, mapping, pos, ret);
- if (err < 0)
+ if (err < 0 && ret > 0)
ret = err;
}
return ret;
@@ -2550,11 +2526,12 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);

- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ if ((ret > 0 || ret == -EIOCBQUEUED) &&
+ ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;

err = sync_page_range(inode, mapping, pos, ret);
- if (err < 0)
+ if (err < 0 && ret > 0)
ret = err;
}
return ret;
--
1.6.0.2