[PATCH 3/4] ext4: Protect ext4_page_mkwrite with sb_start_write - sb_end_write

[Jan Kara <jack@xxxxxxx>]

Since ext4_page_mkwrite() calls into __block_page_mkwrite() it has to
provide freezing protection on it's own.

CC: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 fs/ext4/inode.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 848f436..fbe998b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4733,11 +4733,7 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct 
vm_fault *vmf)
        get_block_t *get_block;
        int retries = 0;
 
-       /*
-        * This check is racy but catches the common case. We rely on
-        * __block_page_mkwrite() to do a reliable check.
-        */
-       vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+       sb_start_write(inode->i_sb);
        /* Delalloc case is easy... */
        if (test_opt(inode->i_sb, DELALLOC) &&
            !ext4_should_journal_data(inode) &&
@@ -4805,5 +4801,6 @@ retry_alloc:
 out_ret:
        ret = block_page_mkwrite_return(ret);
 out:
+       sb_end_write(inode->i_sb);
        return ret;
 }
-- 
1.7.1