[54/90] ext4: skip conversion of uninit extents after direct IO if there isnt any

Greg KH
2009-12-11T04:49:50Z

[-- Attachment #1: 0054-ext4-skip-conversion-of-uninit-extents-after-direct-.patch --]
[-- Type: text/plain, Size: 3414 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
(cherry picked from commit 5f5249507e4b5c4fc0f9c93f33d133d8c95f47e1)

At the end of direct I/O operation, ext4_ext_direct_IO() always called
ext4_convert_unwritten_extents(), regardless of whether there were any
unwritten extents involved in the I/O or not.

This commit adds a state flag so that ext4_ext_direct_IO() only calls
ext4_convert_unwritten_extents() when necessary.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/ext4.h | 1 +
fs/ext4/extents.c | 22 +++++++++++++++++-----
fs/ext4/inode.c | 4 +++-
3 files changed, 21 insertions(+), 6 deletions(-)

--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -318,6 +318,7 @@ static inline __u32 ext4_mask_flags(umod
#define EXT4_STATE_NO_EXPAND 0x00000008 /* No space for expansion */
#define EXT4_STATE_DA_ALLOC_CLOSE 0x00000010 /* Alloc DA blks on close */
#define EXT4_STATE_EXT_MIGRATE 0x00000020 /* Inode is migrating */
+#define EXT4_STATE_DIO_UNWRITTEN 0x00000040 /* need convert on dio done*/

/* Used to pass group descriptor data when online resize is done */
struct ext4_new_group_input {
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3025,12 +3025,18 @@ ext4_ext_handle_uninitialized_extents(ha
ret = ext4_split_unwritten_extents(handle,
inode, path, iblock,
max_blocks, flags);
- /* flag the io_end struct that we need convert when IO done */
+ /*
+ * Flag the inode(non aio case) or end_io struct (aio case)
+ * that this IO needs to convertion to written when IO is
+ * completed
+ */
if (io)
io->flag = DIO_AIO_UNWRITTEN;
+ else
+ EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
goto out;
}
- /* DIO end_io complete, convert the filled extent to written */
+ /* async DIO end_io complete, convert the filled extent to written */
if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
ret = ext4_convert_unwritten_extents_dio(handle, inode,
path);
@@ -3272,10 +3278,16 @@ int ext4_ext_get_blocks(handle_t *handle
* To avoid unecessary convertion for every aio dio rewrite
* to the mid of file, here we flag the IO that is really
* need the convertion.
- *
+ * For non asycn direct IO case, flag the inode state
+ * that we need to perform convertion when IO is done.
*/
- if (io && flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT)
- io->flag = DIO_AIO_UNWRITTEN;
+ if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
+ if (io)
+ io->flag = DIO_AIO_UNWRITTEN;
+ else
+ EXT4_I(inode)->i_state |=
+ EXT4_STATE_DIO_UNWRITTEN;;
+ }
}
err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
if (err) {
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3766,7 +3766,8 @@ static ssize_t ext4_ext_direct_IO(int rw
if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
ext4_free_io_end(iocb->private);
iocb->private = NULL;
- } else if (ret > 0) {
+ } else if (ret > 0 && (EXT4_I(inode)->i_state &
+ EXT4_STATE_DIO_UNWRITTEN)) {
int err;
/*
* for non AIO case, since the IO is already
@@ -3776,6 +3777,7 @@ static ssize_t ext4_ext_direct_IO(int rw
offset, ret);
if (err < 0)
ret = err;
+ EXT4_I(inode)->i_state &= ~EXT4_STATE_DIO_UNWRITTEN;
}
return ret;
}