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author | Tejun Heo <tj@kernel.org> | 2015-05-23 00:13:45 +0300 |
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committer | Jens Axboe <axboe@fb.com> | 2015-06-02 17:33:35 +0300 |
commit | d6c10f1fc8626dc55946f4768ae322b4c57b07dd (patch) | |
tree | 7ec5a99a1a93856f74d0cdfb10c4ff40f77f9818 /include/linux/backing-dev-defs.h | |
parent | 703c270887bb5106c4c46a00cc7477d30d5e04f5 (diff) | |
download | linux-d6c10f1fc8626dc55946f4768ae322b4c57b07dd.tar.xz |
writeback: implement WB_has_dirty_io wb_state flag
Currently, wb_has_dirty_io() determines whether a wb (bdi_writeback)
has any dirty inode by testing all three IO lists on each invocation
without actively keeping track. For cgroup writeback support, a
single bdi will host multiple wb's each of which will host dirty
inodes separately and we'll need to make bdi_has_dirty_io(), which
currently only represents the root wb, aggregate has_dirty_io from all
member wb's, which requires tracking transitions in has_dirty_io state
on each wb.
This patch introduces inode_wb_list_{move|del}_locked() to consolidate
IO list operations leaving queue_io() the only other function which
directly manipulates IO lists (via move_expired_inodes()). All three
functions are updated to call wb_io_lists_[de]populated() which keep
track of whether the wb has dirty inodes or not and record it using
the new WB_has_dirty_io flag. inode_wb_list_moved_locked()'s return
value indicates whether the wb had no dirty inodes before.
mark_inode_dirty() is restructured so that the return value of
inode_wb_list_move_locked() can be used for deciding whether to wake
up the wb.
While at it, change {bdi|wb}_has_dirty_io()'s return values to bool.
These functions were returning 0 and 1 before. Also, add a comment
explaining the synchronization of wb_state flags.
v2: Updated to accommodate b_dirty_time.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/backing-dev-defs.h')
-rw-r--r-- | include/linux/backing-dev-defs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index eb386766b5f3..7a94b7850b7c 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -21,6 +21,7 @@ struct dentry; enum wb_state { WB_registered, /* bdi_register() was done */ WB_writeback_running, /* Writeback is in progress */ + WB_has_dirty_io, /* Dirty inodes on ->b_{dirty|io|more_io} */ }; enum wb_congested_state { |