| Message ID | 20240514-zoned-gc-v1-1-109f1a6c7447@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: zoned: always set aside a zone for relocation | expand |
On Tue, May 14, 2024 at 11:13:21PM +0200, Johannes Thumshirn wrote: > From: Johannes Thumshirn <johannes.thumshirn@wdc.com> > > Reserve one zone as a data relocation target on each mount. If we already > find one empty block group, there's no need to force a chunk allocation, > but we can use this empty data block group as our relocation target. > > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> > --- > fs/btrfs/disk-io.c | 2 ++ > fs/btrfs/zoned.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/zoned.h | 3 +++ > 3 files changed, 65 insertions(+) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index a91a8056758a..0490f2f45fb1 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -3558,6 +3558,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device > } > btrfs_discard_resume(fs_info); > > + btrfs_reserve_relocation_zone(fs_info); > + > if (fs_info->uuid_root && > (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) || > fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) { > diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c > index 4cba80b34387..b752f8c95f40 100644 > --- a/fs/btrfs/zoned.c > +++ b/fs/btrfs/zoned.c > @@ -17,6 +17,7 @@ > #include "fs.h" > #include "accessors.h" > #include "bio.h" > +#include "transaction.h" > > /* Maximum number of zones to report per blkdev_report_zones() call */ > #define BTRFS_REPORT_NR_ZONES 4096 > @@ -2634,3 +2635,62 @@ void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) > } > spin_unlock(&fs_info->zone_active_bgs_lock); > } > + > +static u64 find_empty_block_group(struct btrfs_space_info *sinfo, u64 flags) > +{ > + struct btrfs_block_group *bg; > + > + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) { > + list_for_each_entry(bg, &sinfo->block_groups[i], list) { > + if (bg->flags != flags) > + continue; > + if (bg->used == 0) > + return bg->start; > + } > + } > + > + return 0; > +} > + > +void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info) This function reserves the data relocation block group but not a zone. So, I'd prefer "btrfs_reserve_relocation_block_group" or "..._bg". > +{ > + struct btrfs_root *tree_root = fs_info->tree_root; > + struct btrfs_space_info *sinfo = fs_info->data_sinfo; > + struct btrfs_trans_handle *trans; > + u64 flags = btrfs_get_alloc_profile(fs_info, sinfo->flags); > + u64 bytenr = 0; > + > + lockdep_assert_not_held(&fs_info->relocation_bg_lock); > + > + if (!btrfs_is_zoned(fs_info)) > + return; > + Don't we need to check fs_info->data_reloc_bg first? If we don't find an empty BG and we fail to allocate a new BG, this is going to kill the existing data reloc BG. It's OK for mount time. But, this is going to be called on runtime in the next patch. > + bytenr = find_empty_block_group(sinfo, flags); > + if (!bytenr) { > + int ret; > + > + trans = btrfs_join_transaction(tree_root); > + if (IS_ERR(trans)) > + return; > + > + ret = btrfs_chunk_alloc(trans, flags, CHUNK_ALLOC_FORCE); > + btrfs_end_transaction(trans); I'd like to have a comment on the error case, especially relates to the above point. Is it OK to override fs_info->data_reloc_bg to 0 in the error case? > + > + if (!ret) { > + struct btrfs_block_group *bg; > + > + bytenr = find_empty_block_group(sinfo, flags); > + if (!bytenr) Maybe, same here. This is a case of someone stealing the allocated chunk. Isn't it worth retrying? Especially when this function is called on runtime? > + goto out; > + bg = btrfs_lookup_block_group(fs_info, bytenr); > + ASSERT(bg); > + > + if (!btrfs_zone_activate(bg)) > + bytenr = 0; > + btrfs_put_block_group(bg); > + } > + } > + > +out: > + fs_info->data_reloc_bg = bytenr; > +} > diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h > index 77c4321e331f..048ffada4549 100644 > --- a/fs/btrfs/zoned.h > +++ b/fs/btrfs/zoned.h > @@ -97,6 +97,7 @@ int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info); > int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, > struct btrfs_space_info *space_info, bool do_finish); > void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info); > +void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info); > #else /* CONFIG_BLK_DEV_ZONED */ > static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos, > struct blk_zone *zone) > @@ -271,6 +272,8 @@ static inline int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, > > static inline void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) { } > > +static inline void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info) { } > + > #endif > > static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos) > > -- > 2.35.3 >
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a91a8056758a..0490f2f45fb1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3558,6 +3558,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device } btrfs_discard_resume(fs_info); + btrfs_reserve_relocation_zone(fs_info); + if (fs_info->uuid_root && (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) || fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) { diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 4cba80b34387..b752f8c95f40 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -17,6 +17,7 @@ #include "fs.h" #include "accessors.h" #include "bio.h" +#include "transaction.h" /* Maximum number of zones to report per blkdev_report_zones() call */ #define BTRFS_REPORT_NR_ZONES 4096 @@ -2634,3 +2635,62 @@ void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) } spin_unlock(&fs_info->zone_active_bgs_lock); } + +static u64 find_empty_block_group(struct btrfs_space_info *sinfo, u64 flags) +{ + struct btrfs_block_group *bg; + + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) { + list_for_each_entry(bg, &sinfo->block_groups[i], list) { + if (bg->flags != flags) + continue; + if (bg->used == 0) + return bg->start; + } + } + + return 0; +} + +void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_space_info *sinfo = fs_info->data_sinfo; + struct btrfs_trans_handle *trans; + u64 flags = btrfs_get_alloc_profile(fs_info, sinfo->flags); + u64 bytenr = 0; + + lockdep_assert_not_held(&fs_info->relocation_bg_lock); + + if (!btrfs_is_zoned(fs_info)) + return; + + bytenr = find_empty_block_group(sinfo, flags); + if (!bytenr) { + int ret; + + trans = btrfs_join_transaction(tree_root); + if (IS_ERR(trans)) + return; + + ret = btrfs_chunk_alloc(trans, flags, CHUNK_ALLOC_FORCE); + btrfs_end_transaction(trans); + + if (!ret) { + struct btrfs_block_group *bg; + + bytenr = find_empty_block_group(sinfo, flags); + if (!bytenr) + goto out; + bg = btrfs_lookup_block_group(fs_info, bytenr); + ASSERT(bg); + + if (!btrfs_zone_activate(bg)) + bytenr = 0; + btrfs_put_block_group(bg); + } + } + +out: + fs_info->data_reloc_bg = bytenr; +} diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h index 77c4321e331f..048ffada4549 100644 --- a/fs/btrfs/zoned.h +++ b/fs/btrfs/zoned.h @@ -97,6 +97,7 @@ int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info); int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, bool do_finish); void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info); +void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info); #else /* CONFIG_BLK_DEV_ZONED */ static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos, struct blk_zone *zone) @@ -271,6 +272,8 @@ static inline int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, static inline void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) { } +static inline void btrfs_reserve_relocation_zone(struct btrfs_fs_info *fs_info) { } + #endif static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)