diff mbox

[6/8] nowait aio: ext4

Message ID 20170509122219.31756-7-rgoldwyn@suse.de
State Not Applicable
Headers show

Commit Message

Goldwyn Rodrigues May 9, 2017, 12:22 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

Return EAGAIN if any of the following checks fail for direct I/O:
  + i_rwsem is lockable
  + Writing beyond end of file (will trigger allocation)
  + Blocks are not allocated at the write location

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/ext4/file.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

Comments

Jan Kara May 9, 2017, 2:57 p.m. UTC | #1
On Tue 09-05-17 07:22:17, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Return EAGAIN if any of the following checks fail for direct I/O:
>   + i_rwsem is lockable
>   + Writing beyond end of file (will trigger allocation)
>   + Blocks are not allocated at the write location
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

The patch looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/file.c | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index cefa9835f275..2efdc6d4d3e8 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -216,7 +216,13 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  		return ext4_dax_write_iter(iocb, from);
>  #endif
>  
> -	inode_lock(inode);
> +	if (iocb->ki_flags & IOCB_NOWAIT) {
> +		if (!inode_trylock(inode))
> +			return -EAGAIN;
> +	} else {
> +		inode_lock(inode);
> +	}
> +
>  	ret = ext4_write_checks(iocb, from);
>  	if (ret <= 0)
>  		goto out;
> @@ -235,9 +241,15 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  
>  	iocb->private = &overwrite;
>  	/* Check whether we do a DIO overwrite or not */
> -	if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio &&
> -	    ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from)))
> -		overwrite = 1;
> +	if (o_direct && !unaligned_aio) {
> +		if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
> +			if (ext4_should_dioread_nolock(inode))
> +				overwrite = 1;
> +		} else if (iocb->ki_flags & IOCB_NOWAIT) {
> +			ret = -EAGAIN;
> +			goto out;
> +		}
> +	}
>  
>  	ret = __generic_file_write_iter(iocb, from);
>  	inode_unlock(inode);
> -- 
> 2.12.0
>
diff mbox

Patch

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index cefa9835f275..2efdc6d4d3e8 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -216,7 +216,13 @@  ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		return ext4_dax_write_iter(iocb, from);
 #endif
 
-	inode_lock(inode);
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock(inode))
+			return -EAGAIN;
+	} else {
+		inode_lock(inode);
+	}
+
 	ret = ext4_write_checks(iocb, from);
 	if (ret <= 0)
 		goto out;
@@ -235,9 +241,15 @@  ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	iocb->private = &overwrite;
 	/* Check whether we do a DIO overwrite or not */
-	if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio &&
-	    ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from)))
-		overwrite = 1;
+	if (o_direct && !unaligned_aio) {
+		if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
+			if (ext4_should_dioread_nolock(inode))
+				overwrite = 1;
+		} else if (iocb->ki_flags & IOCB_NOWAIT) {
+			ret = -EAGAIN;
+			goto out;
+		}
+	}
 
 	ret = __generic_file_write_iter(iocb, from);
 	inode_unlock(inode);