| Message ID | 1441702615-18333-2-git-send-email-quwenruo@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, Qu, On 2015/09/08 17:56, Qu Wenruo wrote: > Add new structures and functions for new qgroup reserve implement dirty > phase. > Which will focus on avoiding over-reserve as in that case, which means > for already reserved dirty space range, we won't reserve space again. > > This patch adds the needed structure declaration and comments. > > Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> > --- > fs/btrfs/btrfs_inode.h | 4 ++++ > fs/btrfs/qgroup.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/qgroup.h | 3 +++ > 3 files changed, 65 insertions(+) > > diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h > index 81220b2..e3ece65 100644 > --- a/fs/btrfs/btrfs_inode.h > +++ b/fs/btrfs/btrfs_inode.h > @@ -24,6 +24,7 @@ > #include "extent_io.h" > #include "ordered-data.h" > #include "delayed-inode.h" > +#include "qgroup.h" > > /* > * ordered_data_close is set by truncate when a file that used > @@ -195,6 +196,9 @@ struct btrfs_inode { > struct timespec i_otime; > > struct inode vfs_inode; > + > + /* qgroup dirty map for data space reserve */ > + struct btrfs_qgroup_data_rsv_map *qgroup_rsv_map; > }; > > extern unsigned char btrfs_filetype_table[]; > diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c > index e9ace09..561c36d 100644 > --- a/fs/btrfs/qgroup.c > +++ b/fs/btrfs/qgroup.c > @@ -91,6 +91,64 @@ struct btrfs_qgroup { > u64 new_refcnt; > }; > > +/* > + * Record one range of reserved space. > + */ > +struct data_rsv_range { > + struct rb_node node; > + u64 start; > + u64 len; > +}; > + > +/* > + * Record per inode reserved range. > + * This is mainly used to resolve reserved space leaking problem. > + * One of the cause is the mismatch with reserve and free. > + * > + * New qgroup will handle reserve in two phase. > + * 1) Dirty phase. > + * Pages are just marked dirty, but not written to disk. > + * 2) Flushed phase > + * Pages are written to disk, but transaction is not committed yet. > + * > + * At Diryt phase, we only need to focus on avoiding over-reserve. dirty > + * > + * The idea is like below. > + * 1) Write [0,8K) > + * 0 4K 8K 12K 16K > + * |////////////| > + * Reserve +8K, total reserved: 8K > + * > + * 2) Write [0,4K) > + * 0 4K 8K 12K 16K > + * |////////////| > + * Reserve 0, total reserved 8K > + * > + * 3) Write [12K,16K) > + * 0 4K 8K 12K 16K > + * |////////////| |///////| > + * Reserve +4K, tocal reserved 12K total > + * > + * 4) Flush [0,8K) > + * Can happen without commit transaction, like fallocate will trigger the > + * write. > + * 0 4K 8K 12K 16K > + * |///////| > + * Reserve 0, tocal reserved 12K total Thanks, Tsutomu > + * As the extent is written to disk, not dirty any longer, the range get > + * removed. > + * But as its delayed_refs is not run, its reserved space will not be freed. > + * And things continue to Flushed phase. > + * > + * By this method, we can avoid over-reserve, which will lead to reserved > + * space leak. > + */ > +struct btrfs_qgroup_data_rsv_map { > + struct rb_root root; > + u64 reserved; > + spinlock_t lock; > +}; > + > static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq, > int mod) > { > diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h > index 6387dcf..2f863a4 100644 > --- a/fs/btrfs/qgroup.h > +++ b/fs/btrfs/qgroup.h > @@ -33,6 +33,9 @@ struct btrfs_qgroup_extent_record { > struct ulist *old_roots; > }; > > +/* For per-inode dirty range reserve */ > +struct btrfs_qgroup_data_rsv_map; > + > int btrfs_quota_enable(struct btrfs_trans_handle *trans, > struct btrfs_fs_info *fs_info); > int btrfs_quota_disable(struct btrfs_trans_handle *trans, > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 81220b2..e3ece65 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -24,6 +24,7 @@ #include "extent_io.h" #include "ordered-data.h" #include "delayed-inode.h" +#include "qgroup.h" /* * ordered_data_close is set by truncate when a file that used @@ -195,6 +196,9 @@ struct btrfs_inode { struct timespec i_otime; struct inode vfs_inode; + + /* qgroup dirty map for data space reserve */ + struct btrfs_qgroup_data_rsv_map *qgroup_rsv_map; }; extern unsigned char btrfs_filetype_table[]; diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index e9ace09..561c36d 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -91,6 +91,64 @@ struct btrfs_qgroup { u64 new_refcnt; }; +/* + * Record one range of reserved space. + */ +struct data_rsv_range { + struct rb_node node; + u64 start; + u64 len; +}; + +/* + * Record per inode reserved range. + * This is mainly used to resolve reserved space leaking problem. + * One of the cause is the mismatch with reserve and free. + * + * New qgroup will handle reserve in two phase. + * 1) Dirty phase. + * Pages are just marked dirty, but not written to disk. + * 2) Flushed phase + * Pages are written to disk, but transaction is not committed yet. + * + * At Diryt phase, we only need to focus on avoiding over-reserve. + * + * The idea is like below. + * 1) Write [0,8K) + * 0 4K 8K 12K 16K + * |////////////| + * Reserve +8K, total reserved: 8K + * + * 2) Write [0,4K) + * 0 4K 8K 12K 16K + * |////////////| + * Reserve 0, total reserved 8K + * + * 3) Write [12K,16K) + * 0 4K 8K 12K 16K + * |////////////| |///////| + * Reserve +4K, tocal reserved 12K + * + * 4) Flush [0,8K) + * Can happen without commit transaction, like fallocate will trigger the + * write. + * 0 4K 8K 12K 16K + * |///////| + * Reserve 0, tocal reserved 12K + * As the extent is written to disk, not dirty any longer, the range get + * removed. + * But as its delayed_refs is not run, its reserved space will not be freed. + * And things continue to Flushed phase. + * + * By this method, we can avoid over-reserve, which will lead to reserved + * space leak. + */ +struct btrfs_qgroup_data_rsv_map { + struct rb_root root; + u64 reserved; + spinlock_t lock; +}; + static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq, int mod) { diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h index 6387dcf..2f863a4 100644 --- a/fs/btrfs/qgroup.h +++ b/fs/btrfs/qgroup.h @@ -33,6 +33,9 @@ struct btrfs_qgroup_extent_record { struct ulist *old_roots; }; +/* For per-inode dirty range reserve */ +struct btrfs_qgroup_data_rsv_map; + int btrfs_quota_enable(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); int btrfs_quota_disable(struct btrfs_trans_handle *trans,
Add new structures and functions for new qgroup reserve implement dirty phase. Which will focus on avoiding over-reserve as in that case, which means for already reserved dirty space range, we won't reserve space again. This patch adds the needed structure declaration and comments. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- fs/btrfs/btrfs_inode.h | 4 ++++ fs/btrfs/qgroup.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/qgroup.h | 3 +++ 3 files changed, 65 insertions(+)