ext4: Create helper function for EXT4_IO_END_UNWRITTEN and i_aiodio_unwritten

EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten
should be done simultaneously since ext4_end_io_nolock always clear
the flag and decrease the counter in the same time.

We have found some bugs that the flag is set while leaving
i_aiodio_unwritten unchanged(commit 32c80b32c053d). So this patch just tries
to create a helper function to wrap them to avoid any future bug.
The idea is inspired by Eric.

Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 657e826..604c200 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1275,6 +1275,15 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
                 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
 }
 
+static inline void ext4_set_io_unwritten_flag(struct inode *inode,
+                                             struct ext4_io_end *io_end)
+{
+       if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
+               io_end->flag |= EXT4_IO_END_UNWRITTEN;
+               atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
+       }
+}
+
 /*
  * Inode dynamic state flags
  */

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 36a0f17..a5c8caa 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3472,12 +3472,9 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
                 * that this IO needs to conversion to written when IO is
                 * completed
                 */
-               if (io) {
-                       if (!(io->flag & EXT4_IO_END_UNWRITTEN)) {
-                               io->flag = EXT4_IO_END_UNWRITTEN;
-                               atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
-                       }
-               } else
+               if (io)
+                       ext4_set_io_unwritten_flag(inode, io);
+               else
                        ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
                if (ext4_should_dioread_nolock(inode))
                        map->m_flags |= EXT4_MAP_UNINIT;
@@ -4030,12 +4027,9 @@ got_allocated_blocks:
                 * that we need to perform conversion when IO is done.
                 */
                if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
-                       if (io) {
-                               if (!(io->flag & EXT4_IO_END_UNWRITTEN)) {
-                                       io->flag = EXT4_IO_END_UNWRITTEN;
-                                       atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
-                               }
-                       } else
+                       if (io)
+                               ext4_set_io_unwritten_flag(inode, io);
+                       else
                                ext4_set_inode_state(inode,
                                                     EXT4_STATE_DIO_UNWRITTEN);
                }

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e4b26fa..60af512 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2831,10 +2831,7 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
         * but being more careful is always safe for the future change.
         */
        inode = io_end->inode;
-       if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
-               io_end->flag |= EXT4_IO_END_UNWRITTEN;
-               atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
-       }
+       ext4_set_io_unwritten_flag(inode, io_end);
 
        /* Add the io_end to per-inode completed io list*/
        spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 9eebf44..7ce1d0b 100644 (file)
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -336,10 +336,8 @@ submit_and_retry:
        if ((io_end->num_io_pages >= MAX_IO_PAGES) &&
            (io_end->pages[io_end->num_io_pages-1] != io_page))
                goto submit_and_retry;
-       if (buffer_uninit(bh) && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
-               io_end->flag |= EXT4_IO_END_UNWRITTEN;
-               atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
-       }
+       if (buffer_uninit(bh))
+               ext4_set_io_unwritten_flag(inode, io_end);
        io->io_end->size += bh->b_size;
        io->io_next_block++;
        ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh));