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-   -   block: Remove bi_idx references (http://www.linux-archive.org/device-mapper-development/701597-block-remove-bi_idx-references.html)

Kent Overstreet 09-07-2012 10:59 PM

block: Remove bi_idx references
 
These were harmless but uneccessary,andt getting rid of them makes the
code easier to audit since most of them need to be removed.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
drivers/block/floppy.c | 1 -
drivers/md/dm-verity.c | 2 +-
drivers/md/raid10.c | 1 -
fs/buffer.c | 1 -
fs/jfs/jfs_logmgr.c | 2 --
fs/logfs/dev_bdev.c | 5 -----
mm/page_io.c | 1 -
7 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index a7d6347..2941ce7 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
bio_vec.bv_len = size;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = size;
bio.bi_bdev = bdev;
bio.bi_sector = 0;
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 18ef6c5..6956626 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -496,7 +496,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio,

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio->bi_vcnt - bio->bi_idx;
+ io->io_vec_size = bio_segments(bio);
if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
io->io_vec = io->io_vec_inline;
else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbd08f5..6d06d83 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4249,7 +4249,6 @@ read_more:
read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
read_bio->bi_flags |= 1 << BIO_UPTODATE;
read_bio->bi_vcnt = 0;
- read_bio->bi_idx = 0;
read_bio->bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
diff --git a/fs/buffer.c b/fs/buffer.c
index 58e2e7b..38d8793 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2893,7 +2893,6 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_io_vec[0].bv_offset = bh_offset(bh);

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = bh->b_size;

bio->bi_end_io = end_bio_bh_io_sync;
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 2eb952c..8ae5e35 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2004,7 +2004,6 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
@@ -2145,7 +2144,6 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index e784a21..550475c 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -32,7 +32,6 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
bio_vec.bv_len = PAGE_SIZE;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = PAGE_SIZE;
bio.bi_bdev = bdev;
bio.bi_sector = page->index * (PAGE_SIZE >> 9);
@@ -108,7 +107,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -136,7 +134,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
unlock_page(page);
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -202,7 +199,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -224,7 +220,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
bio->bi_io_vec[i].bv_offset = 0;
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
diff --git a/mm/page_io.c b/mm/page_io.c
index 78eee32..8d3c0c0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -35,7 +35,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
bio->bi_io_vec[0].bv_len = PAGE_SIZE;
bio->bi_io_vec[0].bv_offset = 0;
bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = PAGE_SIZE;
bio->bi_end_io = end_io;
}
--
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Kent Overstreet 09-11-2012 12:22 AM

block: Remove bi_idx references
 
These were harmless but uneccessary,andt getting rid of them makes the
code easier to audit since most of them need to be removed.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
drivers/block/floppy.c | 1 -
drivers/md/dm-verity.c | 2 +-
drivers/md/raid10.c | 1 -
fs/buffer.c | 1 -
fs/jfs/jfs_logmgr.c | 2 --
fs/logfs/dev_bdev.c | 5 -----
mm/page_io.c | 1 -
7 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 95e52879..24e5cef 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
bio_vec.bv_len = size;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = size;
bio.bi_bdev = bdev;
bio.bi_sector = 0;
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 18ef6c5..6956626 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -496,7 +496,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio,

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio->bi_vcnt - bio->bi_idx;
+ io->io_vec_size = bio_segments(bio);
if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
io->io_vec = io->io_vec_inline;
else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbd08f5..6d06d83 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4249,7 +4249,6 @@ read_more:
read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
read_bio->bi_flags |= 1 << BIO_UPTODATE;
read_bio->bi_vcnt = 0;
- read_bio->bi_idx = 0;
read_bio->bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
diff --git a/fs/buffer.c b/fs/buffer.c
index 58e2e7b..38d8793 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2893,7 +2893,6 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_io_vec[0].bv_offset = bh_offset(bh);

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = bh->b_size;

bio->bi_end_io = end_bio_bh_io_sync;
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 2eb952c..8ae5e35 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2004,7 +2004,6 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
@@ -2145,7 +2144,6 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index e784a21..550475c 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -32,7 +32,6 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
bio_vec.bv_len = PAGE_SIZE;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = PAGE_SIZE;
bio.bi_bdev = bdev;
bio.bi_sector = page->index * (PAGE_SIZE >> 9);
@@ -108,7 +107,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -136,7 +134,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
unlock_page(page);
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -202,7 +199,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -224,7 +220,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
bio->bi_io_vec[i].bv_offset = 0;
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
diff --git a/mm/page_io.c b/mm/page_io.c
index 78eee32..8d3c0c0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -35,7 +35,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
bio->bi_io_vec[0].bv_len = PAGE_SIZE;
bio->bi_io_vec[0].bv_offset = 0;
bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = PAGE_SIZE;
bio->bi_end_io = end_io;
}
--
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Tejun Heo 09-20-2012 11:49 PM

block: Remove bi_idx references
 
On Mon, Sep 10, 2012 at 05:22:19PM -0700, Kent Overstreet wrote:
> These were harmless but uneccessary,andt getting rid of them makes the
> code easier to audit since most of them need to be removed.

I find the descriptions a bit too terse. Why do they need to be
removed? So, I suppose you wanted to say explicit initializations to
0 are unnecessary, but there are bio_segments() conversions too.

The patch is simple and this isn't a big deal but I really hope for
better (correct) descriptions.

Thanks.

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Kent Overstreet 09-21-2012 12:04 AM

block: Remove bi_idx references
 
On Thu, Sep 20, 2012 at 04:49:53PM -0700, Tejun Heo wrote:
> On Mon, Sep 10, 2012 at 05:22:19PM -0700, Kent Overstreet wrote:
> > These were harmless but uneccessary,andt getting rid of them makes the
> > code easier to audit since most of them need to be removed.
>
> I find the descriptions a bit too terse. Why do they need to be
> removed? So, I suppose you wanted to say explicit initializations to
> 0 are unnecessary, but there are bio_segments() conversions too.
>
> The patch is simple and this isn't a big deal but I really hope for
> better (correct) descriptions.

It's because for the bvec iterator stuff and immutable bvecs, direct
bi_idx usage tends to be either wrong or unnecessary - I had to audit
all the uses in the kernel.

Reason for doing it now is a later patch moves bi_idx (also bi_sector
and bi_size) into a different struct - so doing these cleanup patches
first means a bit less code churn.

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Kent Overstreet 09-24-2012 10:34 PM

block: Remove bi_idx references
 
For immutable bvecs, all bi_idx usage needs to be audited - so here
we're removing all the unnecessary uses.

Most of these are places where it was being initialized on a bio that
was just allocated, a few others are conversions to standard macros.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
drivers/block/aoe/aoeblk.c | 2 +-
drivers/block/floppy.c | 1 -
drivers/md/dm-verity.c | 2 +-
drivers/md/raid10.c | 1 -
fs/buffer.c | 1 -
fs/jfs/jfs_logmgr.c | 2 --
fs/logfs/dev_bdev.c | 5 -----
mm/page_io.c | 1 -
8 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 321de7b..6e4420a 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -199,7 +199,7 @@ aoeblk_make_request(struct request_queue *q, struct bio *bio)
buf->bio = bio;
buf->resid = bio->bi_size;
buf->sector = bio->bi_sector;
- buf->bv = &bio->bi_io_vec[bio->bi_idx];
+ buf->bv = bio_iovec(bio);
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
buf->bv_off = buf->bv->bv_offset;
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 95e52879..24e5cef 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
bio_vec.bv_len = size;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = size;
bio.bi_bdev = bdev;
bio.bi_sector = 0;
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 8f95664..4431503 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -496,7 +496,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio,

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio->bi_vcnt - bio->bi_idx;
+ io->io_vec_size = bio_segments(bio);
if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
io->io_vec = io->io_vec_inline;
else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbd08f5..6d06d83 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4249,7 +4249,6 @@ read_more:
read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
read_bio->bi_flags |= 1 << BIO_UPTODATE;
read_bio->bi_vcnt = 0;
- read_bio->bi_idx = 0;
read_bio->bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
diff --git a/fs/buffer.c b/fs/buffer.c
index 58e2e7b..38d8793 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2893,7 +2893,6 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_io_vec[0].bv_offset = bh_offset(bh);

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = bh->b_size;

bio->bi_end_io = end_bio_bh_io_sync;
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 2eb952c..8ae5e35 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2004,7 +2004,6 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
@@ -2145,7 +2144,6 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index e784a21..550475c 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -32,7 +32,6 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
bio_vec.bv_len = PAGE_SIZE;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = PAGE_SIZE;
bio.bi_bdev = bdev;
bio.bi_sector = page->index * (PAGE_SIZE >> 9);
@@ -108,7 +107,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -136,7 +134,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
unlock_page(page);
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -202,7 +199,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -224,7 +220,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
bio->bi_io_vec[i].bv_offset = 0;
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
diff --git a/mm/page_io.c b/mm/page_io.c
index 78eee32..8d3c0c0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -35,7 +35,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
bio->bi_io_vec[0].bv_len = PAGE_SIZE;
bio->bi_io_vec[0].bv_offset = 0;
bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = PAGE_SIZE;
bio->bi_end_io = end_io;
}
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Vivek Goyal 10-02-2012 07:24 PM

block: Remove bi_idx references
 
On Mon, Sep 24, 2012 at 03:34:49PM -0700, Kent Overstreet wrote:

[..]
> diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
> index 95e52879..24e5cef 100644
> --- a/drivers/block/floppy.c
> +++ b/drivers/block/floppy.c
> @@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
> bio_vec.bv_len = size;
> bio_vec.bv_offset = 0;
> bio.bi_vcnt = 1;
> - bio.bi_idx = 0;

So leaving bio.bi_idx uninitialized is safer than setting it to zero? Can
you explain a bit more that why this change is required?

Thanks
Vivek

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Kent Overstreet 10-02-2012 08:16 PM

block: Remove bi_idx references
 
On Tue, Oct 02, 2012 at 03:24:34PM -0400, Vivek Goyal wrote:
> On Mon, Sep 24, 2012 at 03:34:49PM -0700, Kent Overstreet wrote:
>
> [..]
> > diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
> > index 95e52879..24e5cef 100644
> > --- a/drivers/block/floppy.c
> > +++ b/drivers/block/floppy.c
> > @@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
> > bio_vec.bv_len = size;
> > bio_vec.bv_offset = 0;
> > bio.bi_vcnt = 1;
> > - bio.bi_idx = 0;
>
> So leaving bio.bi_idx uninitialized is safer than setting it to zero? Can
> you explain a bit more that why this change is required?

It's not uninitialized, because it just called bio_init() - it was
entirely redundant before.

It's not strictly necessary, but immutable bio vecs require getting rid
of a lot of bi_idx usage, and everything that's left is either
unecessary or better/cleaner done some other way, so it's best to just
get rid of all of them - immutable bvecs changes the semantics of bi_idx
just enough that directly using it tends to be wrong.

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Kent Overstreet 10-15-2012 08:08 PM

block: Remove bi_idx references
 
For immutable bvecs, all bi_idx usage needs to be audited - so here
we're removing all the unnecessary uses.

Most of these are places where it was being initialized on a bio that
was just allocated, a few others are conversions to standard macros.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
drivers/block/aoe/aoeblk.c | 2 +-
drivers/block/floppy.c | 1 -
drivers/md/dm-verity.c | 2 +-
drivers/md/raid10.c | 1 -
fs/buffer.c | 1 -
fs/jfs/jfs_logmgr.c | 2 --
fs/logfs/dev_bdev.c | 5 -----
mm/page_io.c | 1 -
8 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 321de7b..6e4420a 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -199,7 +199,7 @@ aoeblk_make_request(struct request_queue *q, struct bio *bio)
buf->bio = bio;
buf->resid = bio->bi_size;
buf->sector = bio->bi_sector;
- buf->bv = &bio->bi_io_vec[bio->bi_idx];
+ buf->bv = bio_iovec(bio);
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
buf->bv_off = buf->bv->bv_offset;
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 95e52879..24e5cef 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
bio_vec.bv_len = size;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = size;
bio.bi_bdev = bdev;
bio.bi_sector = 0;
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 8f95664..4431503 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -496,7 +496,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio,

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio->bi_vcnt - bio->bi_idx;
+ io->io_vec_size = bio_segments(bio);
if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
io->io_vec = io->io_vec_inline;
else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbd08f5..6d06d83 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4249,7 +4249,6 @@ read_more:
read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
read_bio->bi_flags |= 1 << BIO_UPTODATE;
read_bio->bi_vcnt = 0;
- read_bio->bi_idx = 0;
read_bio->bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
diff --git a/fs/buffer.c b/fs/buffer.c
index 58e2e7b..38d8793 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2893,7 +2893,6 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_io_vec[0].bv_offset = bh_offset(bh);

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = bh->b_size;

bio->bi_end_io = end_bio_bh_io_sync;
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 2eb952c..8ae5e35 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2004,7 +2004,6 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
@@ -2145,7 +2144,6 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index e784a21..550475c 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -32,7 +32,6 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
bio_vec.bv_len = PAGE_SIZE;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = PAGE_SIZE;
bio.bi_bdev = bdev;
bio.bi_sector = page->index * (PAGE_SIZE >> 9);
@@ -108,7 +107,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -136,7 +134,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
unlock_page(page);
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -202,7 +199,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -224,7 +220,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
bio->bi_io_vec[i].bv_offset = 0;
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
diff --git a/mm/page_io.c b/mm/page_io.c
index 78eee32..8d3c0c0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -35,7 +35,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
bio->bi_io_vec[0].bv_len = PAGE_SIZE;
bio->bi_io_vec[0].bv_offset = 0;
bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = PAGE_SIZE;
bio->bi_end_io = end_io;
}
--
1.7.12

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Kent Overstreet 10-15-2012 08:09 PM

block: Remove bi_idx references
 
These were harmless but uneccessary,andt getting rid of them makes the
code easier to audit since most of them need to be removed.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
drivers/block/floppy.c | 1 -
drivers/md/dm-verity.c | 2 +-
drivers/md/raid10.c | 1 -
fs/buffer.c | 1 -
fs/jfs/jfs_logmgr.c | 2 --
fs/logfs/dev_bdev.c | 5 -----
mm/page_io.c | 1 -
7 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 95e52879..24e5cef 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3778,7 +3778,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
bio_vec.bv_len = size;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = size;
bio.bi_bdev = bdev;
bio.bi_sector = 0;
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 18ef6c5..6956626 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -496,7 +496,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio,

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio->bi_vcnt - bio->bi_idx;
+ io->io_vec_size = bio_segments(bio);
if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
io->io_vec = io->io_vec_inline;
else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbd08f5..6d06d83 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4249,7 +4249,6 @@ read_more:
read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
read_bio->bi_flags |= 1 << BIO_UPTODATE;
read_bio->bi_vcnt = 0;
- read_bio->bi_idx = 0;
read_bio->bi_size = 0;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
diff --git a/fs/buffer.c b/fs/buffer.c
index 58e2e7b..38d8793 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2893,7 +2893,6 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_io_vec[0].bv_offset = bh_offset(bh);

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = bh->b_size;

bio->bi_end_io = end_bio_bh_io_sync;
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 2eb952c..8ae5e35 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2004,7 +2004,6 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
@@ -2145,7 +2144,6 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_io_vec[0].bv_offset = bp->l_offset;

bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = LOGPSIZE;

bio->bi_end_io = lbmIODone;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index e784a21..550475c 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -32,7 +32,6 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
bio_vec.bv_len = PAGE_SIZE;
bio_vec.bv_offset = 0;
bio.bi_vcnt = 1;
- bio.bi_idx = 0;
bio.bi_size = PAGE_SIZE;
bio.bi_bdev = bdev;
bio.bi_sector = page->index * (PAGE_SIZE >> 9);
@@ -108,7 +107,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -136,7 +134,6 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
unlock_page(page);
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -202,7 +199,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
if (i >= max_pages) {
/* Block layer cannot split bios :( */
bio->bi_vcnt = i;
- bio->bi_idx = 0;
bio->bi_size = i * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
@@ -224,7 +220,6 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
bio->bi_io_vec[i].bv_offset = 0;
}
bio->bi_vcnt = nr_pages;
- bio->bi_idx = 0;
bio->bi_size = nr_pages * PAGE_SIZE;
bio->bi_bdev = super->s_bdev;
bio->bi_sector = ofs >> 9;
diff --git a/mm/page_io.c b/mm/page_io.c
index 78eee32..8d3c0c0 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -35,7 +35,6 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
bio->bi_io_vec[0].bv_len = PAGE_SIZE;
bio->bi_io_vec[0].bv_offset = 0;
bio->bi_vcnt = 1;
- bio->bi_idx = 0;
bio->bi_size = PAGE_SIZE;
bio->bi_end_io = end_io;
}
--
1.7.12

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