Pass GFP_KERNEL instead of GFP_NOFS to the blkdev_zone_mgmt() call in
zonefs_zone_mgmt().
As as zonefs_zone_mgmt() and zonefs_inode_zone_mgmt() are never called
from a place that can recurse back into the filesystem on memory reclaim,
it is save to call blkdev_zone_mgmt() with GFP_KERNEL.
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Johannes Thumshirn <[email protected]>
---
fs/zonefs/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 93971742613a..63fbac018c04 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -113,7 +113,7 @@ static int zonefs_zone_mgmt(struct super_block *sb,
trace_zonefs_zone_mgmt(sb, z, op);
ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,
- z->z_size >> SECTOR_SHIFT, GFP_NOFS);
+ z->z_size >> SECTOR_SHIFT, GFP_KERNEL);
if (ret) {
zonefs_err(sb,
"Zone management operation %s at %llu failed %d\n",
--
2.43.0
On 1/29/24 16:52, Johannes Thumshirn wrote:
> Pass GFP_KERNEL instead of GFP_NOFS to the blkdev_zone_mgmt() call in
> zonefs_zone_mgmt().
>
> As as zonefs_zone_mgmt() and zonefs_inode_zone_mgmt() are never called
> from a place that can recurse back into the filesystem on memory reclaim,
> it is save to call blkdev_zone_mgmt() with GFP_KERNEL.
s/save/safe
> Link: https://lore.kernel.org/all/[email protected]/
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
> fs/zonefs/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 93971742613a..63fbac018c04 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -113,7 +113,7 @@ static int zonefs_zone_mgmt(struct super_block *sb,
>
> trace_zonefs_zone_mgmt(sb, z, op);
> ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,
> - z->z_size >> SECTOR_SHIFT, GFP_NOFS);
> + z->z_size >> SECTOR_SHIFT, GFP_KERNEL);
> if (ret) {
> zonefs_err(sb,
> "Zone management operation %s at %llu failed %d\n",
I think this is OK but I will need a little more time to fully convince myself.
So let me look again at the code to check all the calls contexts.
--
Damien Le Moal
Western Digital Research
On 1/29/24 16:52, Johannes Thumshirn wrote:
> Pass GFP_KERNEL instead of GFP_NOFS to the blkdev_zone_mgmt() call in
> zonefs_zone_mgmt().
>
> As as zonefs_zone_mgmt() and zonefs_inode_zone_mgmt() are never called
> from a place that can recurse back into the filesystem on memory reclaim,
> it is save to call blkdev_zone_mgmt() with GFP_KERNEL.
>
> Link: https://lore.kernel.org/all/[email protected]/
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
> fs/zonefs/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 93971742613a..63fbac018c04 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -113,7 +113,7 @@ static int zonefs_zone_mgmt(struct super_block *sb,
>
> trace_zonefs_zone_mgmt(sb, z, op);
> ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,
> - z->z_size >> SECTOR_SHIFT, GFP_NOFS);
> + z->z_size >> SECTOR_SHIFT, GFP_KERNEL);
> if (ret) {
> zonefs_err(sb,
> "Zone management operation %s at %llu failed %d\n",
>
Given that zonefs_inode_zone_mgmt() which calls zonefs_zone_mgmt() is only used
for sequential zone inodes, and that these inodes cannot be written with
buffered IOs, I think this is safe as we will never have dirty pages to
writeback for reclaim. So there should be no risk of re-entering the FS on
reclaim with GFP_KERNEL.
So:
Acked-by: Damien Le Moal <[email protected]>
--
Damien Le Moal
Western Digital Research