| Message ID | 20240128-zonefs_nofs-v3-1-ae3b7c8def61@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: remove gfp_mask for blkdev_zone_mgmt() | expand |
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/ZZcgXI46AinlcBDP@casper.infradead.org/ > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> > --- > 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.
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/ZZcgXI46AinlcBDP@casper.infradead.org/ > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> > --- > 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 <dlemoal@kernel.org>
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",
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/ZZcgXI46AinlcBDP@casper.infradead.org/ Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> --- fs/zonefs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)