ceph: Don't use ceph-sync-mode for synchronous-fs.

Sending reads and writes through the sync read/write paths bypasses the
page cache, which is not expected or generally a good idea.  Removing
the write check is safe as there is a conditional vfs_fsync_range() later
in ceph_aio_write that already checks for the same flag (via
IS_SYNC(inode)).

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 7d4e769f1d3d1996d4ff0c07dd8163b2923c7784..63ec830b93061fcc18ea49a1cab156df5c5a7ca2 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -659,7 +659,6 @@ again:
 
        if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
            (iocb->ki_filp->f_flags & O_DIRECT) ||
-           (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
            (fi->flags & CEPH_F_SYNC))
                /* hmm, this isn't really async... */
                ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
@@ -763,7 +762,6 @@ retry_snap:
 
        if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
            (iocb->ki_filp->f_flags & O_DIRECT) ||
-           (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
            (fi->flags & CEPH_F_SYNC)) {
                mutex_unlock(&inode->i_mutex);
                written = ceph_sync_write(file, iov->iov_base, count,