openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

iomap: refactor iomap_dio_actor 

Split the function up into two helpers for the bio based I/O and hole
case, and a small helper to call the two.  This separates the code a
little better in preparation for supporting I/O to inline data.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2018-07-03 09:07:46 -07:00 committed by Darrick J. Wong
parent c03cea4214
commit 09230435df
1 changed files with 52 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
fs/iomap.c
View File

@ -1327,10 +1327,9 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
}
static loff_t
iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
void *data, struct iomap *iomap)
iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
struct iomap_dio *dio, struct iomap *iomap)
{
struct iomap_dio *dio = data;
unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
unsigned int fs_block_size = i_blocksize(inode), pad;
unsigned int align = iov_iter_alignment(dio->submit.iter);
@ -1344,41 +1343,27 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
if ((pos | length | align) & ((1 << blkbits) - 1))
return -EINVAL;
switch (iomap->type) {
case IOMAP_HOLE:
if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
return -EIO;
/*FALLTHRU*/
case IOMAP_UNWRITTEN:
if (!(dio->flags & IOMAP_DIO_WRITE)) {
length = iov_iter_zero(length, dio->submit.iter);
dio->size += length;
return length;
}
if (iomap->type == IOMAP_UNWRITTEN) {
dio->flags |= IOMAP_DIO_UNWRITTEN;
need_zeroout = true;
break;
case IOMAP_MAPPED:
if (iomap->flags & IOMAP_F_SHARED)
dio->flags |= IOMAP_DIO_COW;
if (iomap->flags & IOMAP_F_NEW) {
need_zeroout = true;
} else {
/*
* Use a FUA write if we need datasync semantics, this
* is a pure data IO that doesn't require any metadata
* updates and the underlying device supports FUA. This
* allows us to avoid cache flushes on IO completion.
*/
if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
(dio->flags & IOMAP_DIO_WRITE_FUA) &&
blk_queue_fua(bdev_get_queue(iomap->bdev)))
use_fua = true;
}
break;
default:
WARN_ON_ONCE(1);
return -EIO;
}
if (iomap->flags & IOMAP_F_SHARED)
dio->flags |= IOMAP_DIO_COW;
if (iomap->flags & IOMAP_F_NEW) {
need_zeroout = true;
} else {
/*
* Use a FUA write if we need datasync semantics, this
* is a pure data IO that doesn't require any metadata
* updates and the underlying device supports FUA. This
* allows us to avoid cache flushes on IO completion.
*/
if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
(dio->flags & IOMAP_DIO_WRITE_FUA) &&
blk_queue_fua(bdev_get_queue(iomap->bdev)))
use_fua = true;
}
/*
@ -1457,6 +1442,37 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
return copied;
}
static loff_t
iomap_dio_hole_actor(loff_t length, struct iomap_dio *dio)
{
length = iov_iter_zero(length, dio->submit.iter);
dio->size += length;
return length;
}
static loff_t
iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
void *data, struct iomap *iomap)
{
struct iomap_dio *dio = data;
switch (iomap->type) {
case IOMAP_HOLE:
if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
return -EIO;
return iomap_dio_hole_actor(length, dio);
case IOMAP_UNWRITTEN:
if (!(dio->flags & IOMAP_DIO_WRITE))
return iomap_dio_hole_actor(length, dio);
return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
case IOMAP_MAPPED:
return iomap_dio_bio_actor(inode, pos, length, dio, iomap);
default:
WARN_ON_ONCE(1);
return -EIO;
}
}
/*
* iomap_dio_rw() always completes O_[D]SYNC writes regardless of whether the IO
* is being issued as AIO or not. This allows us to optimise pure data writes