* re: Btrfs: split up __extent_writepage to lower stack usage
@ 2014-06-09 14:40 Dan Carpenter
2014-06-09 14:48 ` Chris Mason
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2014-06-09 14:40 UTC (permalink / raw)
To: clm; +Cc: linux-btrfs
Hello Chris Mason,
The patch 263524b4ac6b: "Btrfs: split up __extent_writepage to lower
stack usage" from May 21, 2014, leads to the following static checker
warning:
fs/btrfs/extent_io.c:4071 try_release_extent_state()
warn: use 'mask' here instead of GFP_XXX?
fs/btrfs/extent_io.c
4053 static int try_release_extent_state(struct extent_map_tree *map,
4054 struct extent_io_tree *tree,
4055 struct page *page, gfp_t mask)
4056 {
4057 u64 start = page_offset(page);
4058 u64 end = start + PAGE_CACHE_SIZE - 1;
4059 int ret = 1;
4060
4061 if (test_range_bit(tree, start, end,
4062 EXTENT_IOBITS, 0, NULL))
4063 ret = 0;
4064 else {
4065 if ((mask & GFP_NOFS) == GFP_NOFS)
4066 mask = GFP_NOFS;
4067 /*
4068 * at this point we can safely clear everything except the
4069 * locked bit and the nodatasum bit
4070 */
4071 ret = clear_extent_bit(tree, start, end,
4072 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
4073 0, 0, NULL, GFP_ATOMIC);
^^^^^^^^^^
It upsets the static checkers to keep "mask" around when we don't use it
anymore.
4074
4075 /* if clear_extent_bit failed for enomem reasons,
4076 * we can't allow the release to continue.
4077 */
4078 if (ret < 0)
4079 ret = 0;
4080 else
4081 ret = 1;
4082 }
4083 return ret;
4084 }
regards,
dan carpenter
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Btrfs: split up __extent_writepage to lower stack usage
2014-06-09 14:40 Btrfs: split up __extent_writepage to lower stack usage Dan Carpenter
@ 2014-06-09 14:48 ` Chris Mason
0 siblings, 0 replies; 2+ messages in thread
From: Chris Mason @ 2014-06-09 14:48 UTC (permalink / raw)
To: Dan Carpenter; +Cc: linux-btrfs
On 06/09/2014 10:40 AM, Dan Carpenter wrote:
> Hello Chris Mason,
>
> The patch 263524b4ac6b: "Btrfs: split up __extent_writepage to lower
> stack usage" from May 21, 2014, leads to the following static checker
> warning:
>
> fs/btrfs/extent_io.c:4071 try_release_extent_state()
> warn: use 'mask' here instead of GFP_XXX?
>
> fs/btrfs/extent_io.c
> 4053 static int try_release_extent_state(struct extent_map_tree *map,
> 4054 struct extent_io_tree *tree,
> 4055 struct page *page, gfp_t mask)
> 4056 {
> 4057 u64 start = page_offset(page);
> 4058 u64 end = start + PAGE_CACHE_SIZE - 1;
> 4059 int ret = 1;
> 4060
> 4061 if (test_range_bit(tree, start, end,
> 4062 EXTENT_IOBITS, 0, NULL))
> 4063 ret = 0;
> 4064 else {
> 4065 if ((mask & GFP_NOFS) == GFP_NOFS)
> 4066 mask = GFP_NOFS;
> 4067 /*
> 4068 * at this point we can safely clear everything except the
> 4069 * locked bit and the nodatasum bit
> 4070 */
> 4071 ret = clear_extent_bit(tree, start, end,
> 4072 ~(EXTENT_LOCKED | EXTENT_NODATASUM),
> 4073 0, 0, NULL, GFP_ATOMIC);
> ^^^^^^^^^^
> It upsets the static checkers to keep "mask" around when we don't use it
> anymore.
Thanks Dan, I'll switch this around to make it more clear.
-chris
^ permalink raw reply [flat|nested] 2+ messages in thread
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