Re: [PATCH 5/5] btrfs: Replace BUG_ON with ASSERT in find_lock_delalloc_range

[Anand Jain]

On 10/26/2018 07:43 PM, Nikolay Borisov wrote:

lock_delalloc_pages should only return 2 values - 0 in case of success
and -EAGAIN if the range of pages to be locked should be shrunk due to
some of gone. Manual inspections confirms that this is
indeed the case since __process_pages_contig is where lock_delalloc_pages
gets its return value. The latter always returns 0  or -EAGAIN so the
invariant holds. No functional changes.

Signed-off-by: Nikolay Borisov 


Reviewed-by: Anand Jain 

Thanks, Anand


---
  fs/btrfs/extent_io.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1a9a521aefe5..94bc53472031 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1606,6 +1606,7 @@ static noinline_for_stack u64 
find_lock_delalloc_range(struct inode *inode,
/* step two, lock all the pages after the page that has start */
ret = lock_delalloc_pages(inode, locked_page,
  delalloc_start, delalloc_end);
+   ASSERT(!ret || ret == -EAGAIN);
if (ret == -EAGAIN) {
/* some of the pages are gone, lets avoid looping by
 * shortening the size of the delalloc range we're searching
@@ -1621,7 +1622,6 @@ static noinline_for_stack u64 
find_lock_delalloc_range(struct inode *inode,
goto out_failed;
}
}
-   BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
  
  	/* step three, lock the state bits for the whole range */

lock_extent_bits(tree, delalloc_start, delalloc_end, _state);

Re: [PATCH 5/5] btrfs: Replace BUG_ON with ASSERT in find_lock_delalloc_range

[Qu Wenruo]

On 2018/10/26 下午7:43, Nikolay Borisov wrote:
> lock_delalloc_pages should only return 2 values - 0 in case of success
> and -EAGAIN if the range of pages to be locked should be shrunk due to
> some of gone. Manual inspections confirms that this is
> indeed the case since __process_pages_contig is where lock_delalloc_pages
> gets its return value. The latter always returns 0  or -EAGAIN so the
> invariant holds. No functional changes.
> 
> Signed-off-by: Nikolay Borisov 

Reviewed-by: Qu Wenruo 

Thanks,
Qu

> ---
>  fs/btrfs/extent_io.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 1a9a521aefe5..94bc53472031 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -1606,6 +1606,7 @@ static noinline_for_stack u64 
> find_lock_delalloc_range(struct inode *inode,
>   /* step two, lock all the pages after the page that has start */
>   ret = lock_delalloc_pages(inode, locked_page,
> delalloc_start, delalloc_end);
> + ASSERT(!ret || ret == -EAGAIN);
>   if (ret == -EAGAIN) {
>   /* some of the pages are gone, lets avoid looping by
>* shortening the size of the delalloc range we're searching
> @@ -1621,7 +1622,6 @@ static noinline_for_stack u64 
> find_lock_delalloc_range(struct inode *inode,
>   goto out_failed;
>   }
>   }
> - BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
>  
>   /* step three, lock the state bits for the whole range */
>   lock_extent_bits(tree, delalloc_start, delalloc_end, _state);
> 

[PATCH 5/5] btrfs: Replace BUG_ON with ASSERT in find_lock_delalloc_range

[Nikolay Borisov]

lock_delalloc_pages should only return 2 values - 0 in case of success
and -EAGAIN if the range of pages to be locked should be shrunk due to
some of gone. Manual inspections confirms that this is
indeed the case since __process_pages_contig is where lock_delalloc_pages
gets its return value. The latter always returns 0  or -EAGAIN so the
invariant holds. No functional changes.

Signed-off-by: Nikolay Borisov 
---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1a9a521aefe5..94bc53472031 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1606,6 +1606,7 @@ static noinline_for_stack u64 
find_lock_delalloc_range(struct inode *inode,
/* step two, lock all the pages after the page that has start */
ret = lock_delalloc_pages(inode, locked_page,
  delalloc_start, delalloc_end);
+   ASSERT(!ret || ret == -EAGAIN);
if (ret == -EAGAIN) {
/* some of the pages are gone, lets avoid looping by
 * shortening the size of the delalloc range we're searching
@@ -1621,7 +1622,6 @@ static noinline_for_stack u64 
find_lock_delalloc_range(struct inode *inode,
goto out_failed;
}
}
-   BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */
 
/* step three, lock the state bits for the whole range */
lock_extent_bits(tree, delalloc_start, delalloc_end, _state);
-- 
2.7.4