From: Tao Ma <boyu.mt@xxxxxxxxxx>
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. So this patch just tries to creat a helper function to wrap them
to avoid any future bug. The idea is inspired by Eric.
Cc: Eric Sandeen <sandeen@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Tao Ma <boyu.mt@xxxxxxxxxx>
---
Ted,
This patch is based on the patch with subject "ext4: Resolve the hang
of direct i/o read in handling EXT4_IO_END_UNWRITTEN.". I meant it for the next
merge window, but if you think it is also ok for 3.1, go ahead.
fs/ext4/ext4.h | 11 +++++++++++
fs/ext4/extents.c | 10 ++--------
fs/ext4/inode.c | 5 +----
fs/ext4/page-io.c | 6 ++----
4 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e717dfd..514f670 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1247,6 +1247,17 @@ 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 int ext4_set_io_unwritten_flag(struct inode *inode,
+ struct ext4_io_end *io_end)
+{
+ if (io_end && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
+ io_end->flag |= EXT4_IO_END_UNWRITTEN;
+ atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
+ return 1;
+ }
+
+ return 0;
+}
/*
* Inode dynamic state flags
*/
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 57cf568..c0f8655 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3190,10 +3190,7 @@ 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 && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
- io->flag = EXT4_IO_END_UNWRITTEN;
- atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
- } else
+ if (!ext4_set_io_unwritten_flag(inode, io))
ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
if (ext4_should_dioread_nolock(inode))
map->m_flags |= EXT4_MAP_UNINIT;
@@ -3572,10 +3569,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
* that we need to perform conversion when IO is done.
*/
if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
- if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
- io->flag = EXT4_IO_END_UNWRITTEN;
- atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
- } else
+ if (!ext4_set_io_unwritten_flag(inode, io))
ext4_set_inode_state(inode,
EXT4_STATE_DIO_UNWRITTEN);
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 40c0b10..128493b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2673,10 +2673,7 @@ 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 78839af..edd2f7b 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -334,10 +334,8 @@ 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));
--
1.7.0.4
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