Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO
On 3.03.2018 02:24, Andrew Morton wrote:
> On Mon, 26 Feb 2018 11:54:30 +0200 Nikolay Borisov wrote:
>
>> We already get the block counts and the calculate the end block at the
>> beginning of the function. Let's use the local variables for consistency and
>> readability. No functional changes
>>
>
> Fair enough.
>
>> --- a/fs/direct-io.c
>> +++ b/fs/direct-io.c
>> @@ -1200,7 +1200,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode
>> *inode,
>> }
>>
>> /* watch out for a 0 len io from a tricksy fs */
>> -if (iov_iter_rw(iter) == READ && !iov_iter_count(iter))
>> +if (iov_iter_rw(iter) == READ && !count)
>> return 0;
>>
>> dio = kmem_cache_alloc(dio_cache, GFP_KERNEL);
>> @@ -1316,8 +1316,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode
>> *inode,
>>
>> dio->should_dirty = (iter->type == ITER_IOVEC);
>> sdio.iter = iter;
>> -sdio.final_block_in_request =
>> -(offset + iov_iter_count(iter)) >> blkbits;
>> +sdio.final_block_in_request = end >> blkbits;
>>
>> /*
>> * In case of non-aligned buffers, we may need 2 more
>
> It's always scary to see a local being used in this fashion so far away
> from where it was initialized. However, we can get our warm fuzzy
> feelings by doing this:
>
Good point !
> --- a/fs/direct-io.c~direct-io-minor-cleanups-in-do_blockdev_direct_io-fix
> +++ a/fs/direct-io.c
> @@ -1178,9 +1178,9 @@ do_blockdev_direct_IO(struct kiocb *iocb
> unsigned blkbits = i_blkbits;
> unsigned blocksize_mask = (1 << blkbits) - 1;
> ssize_t retval = -EINVAL;
> - size_t count = iov_iter_count(iter);
> + const size_t count = iov_iter_count(iter);
> loff_t offset = iocb->ki_pos;
> - loff_t end = offset + count;
> + const loff_t end = offset + count;
> struct dio *dio;
> struct dio_submit sdio = { 0, };
> struct buffer_head map_bh = { 0, };
> _
I assume you don't want me to resend but will just fold the changes
yourself?
>
>
Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO
On Mon, 26 Feb 2018 11:54:30 +0200 Nikolay Borisov wrote:
> We already get the block counts and the calculate the end block at the
> beginning of the function. Let's use the local variables for consistency and
> readability. No functional changes
>
Fair enough.
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -1200,7 +1200,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode
> *inode,
> }
>
> /* watch out for a 0 len io from a tricksy fs */
> - if (iov_iter_rw(iter) == READ && !iov_iter_count(iter))
> + if (iov_iter_rw(iter) == READ && !count)
> return 0;
>
> dio = kmem_cache_alloc(dio_cache, GFP_KERNEL);
> @@ -1316,8 +1316,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode
> *inode,
>
> dio->should_dirty = (iter->type == ITER_IOVEC);
> sdio.iter = iter;
> - sdio.final_block_in_request =
> - (offset + iov_iter_count(iter)) >> blkbits;
> + sdio.final_block_in_request = end >> blkbits;
>
> /*
>* In case of non-aligned buffers, we may need 2 more
It's always scary to see a local being used in this fashion so far away
from where it was initialized. However, we can get our warm fuzzy
feelings by doing this:
--- a/fs/direct-io.c~direct-io-minor-cleanups-in-do_blockdev_direct_io-fix
+++ a/fs/direct-io.c
@@ -1178,9 +1178,9 @@ do_blockdev_direct_IO(struct kiocb *iocb
unsigned blkbits = i_blkbits;
unsigned blocksize_mask = (1 << blkbits) - 1;
ssize_t retval = -EINVAL;
- size_t count = iov_iter_count(iter);
+ const size_t count = iov_iter_count(iter);
loff_t offset = iocb->ki_pos;
- loff_t end = offset + count;
+ const loff_t end = offset + count;
struct dio *dio;
struct dio_submit sdio = { 0, };
struct buffer_head map_bh = { 0, };
_
Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO
On 2.08.2017 10:10, Nikolay Borisov wrote: > We already get the block counts and the calculate the end block at the > beginning of the function. Let's use the local variables for consistency and > readability. No functional changes > > Signed-off-by: Nikolay Borisov > --- > fs/direct-io.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index 08cf27811e5a..987bc17a5f5e 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -1139,7 +1139,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode > *inode, > } > > /* watch out for a 0 len io from a tricksy fs */ > - if (iov_iter_rw(iter) == READ && !iov_iter_count(iter)) > + if (iov_iter_rw(iter) == READ && !count) > return 0; > > dio = kmem_cache_alloc(dio_cache, GFP_KERNEL); > @@ -1248,8 +1248,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode > *inode, > > dio->should_dirty = (iter->type == ITER_IOVEC); > sdio.iter = iter; > - sdio.final_block_in_request = > - (offset + iov_iter_count(iter)) >> blkbits; > + sdio.final_block_in_request = end >> blkbits; > > /* >* In case of non-aligned buffers, we may need 2 more > Ping on that forgotten one :)
Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO
On 2.08.2017 10:10, Nikolay Borisov wrote: > We already get the block counts and the calculate the end block at the > beginning of the function. Let's use the local variables for consistency and > readability. No functional changes > > Signed-off-by: Nikolay Borisov > --- ping > fs/direct-io.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index 08cf27811e5a..987bc17a5f5e 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -1139,7 +1139,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode > *inode, > } > > /* watch out for a 0 len io from a tricksy fs */ > - if (iov_iter_rw(iter) == READ && !iov_iter_count(iter)) > + if (iov_iter_rw(iter) == READ && !count) > return 0; > > dio = kmem_cache_alloc(dio_cache, GFP_KERNEL); > @@ -1248,8 +1248,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode > *inode, > > dio->should_dirty = (iter->type == ITER_IOVEC); > sdio.iter = iter; > - sdio.final_block_in_request = > - (offset + iov_iter_count(iter)) >> blkbits; > + sdio.final_block_in_request = end >> blkbits; > > /* >* In case of non-aligned buffers, we may need 2 more >
Re: [PATCH] direct-io: Minor cleanups in do_blockdev_direct_IO
Nikolay Borisov writes: > We already get the block counts and the calculate the end block at the > beginning of the function. Let's use the local variables for consistency and > readability. No functional changes > > Signed-off-by: Nikolay Borisov Looks ok to me. Reviewed-by: Jeff Moyer
