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| author | Tejun Heo <tj@kernel.org> | 2015-06-16 18:48:30 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-06-17 12:47:37 -0600 |
| commit | dd73e4b7df9589fa603fc6d128b4f6cabb250e8e (patch) | |
| tree | e729cdad58a661c89cf2203b3f2b90de3cf1e6e5 /fs/fs-writeback.c | |
| parent | 412a19b64ad17f7650ff778fd2cb9032938cf71f (diff) | |
| download | lwn-dd73e4b7df9589fa603fc6d128b4f6cabb250e8e.tar.gz lwn-dd73e4b7df9589fa603fc6d128b4f6cabb250e8e.zip | |
writeback: do foreign inode detection iff cgroup writeback is enabled
Currently, even when a filesystem doesn't set the FS_CGROUP_WRITEBACK
flag, if the filesystem uses wbc_init_bio() and wbc_account_io(), the
foreign inode detection and migration logic still ends up activating
cgroup writeback which is unexpected. This patch ensures that the
foreign inode detection logic stays disabled when inode_cgwb_enabled()
is false by not associating writeback_control's with bdi_writeback's.
This also avoids unnecessary operations in wbc_init_bio(),
wbc_account_io() and wbc_detach_inode() for filesystems which don't
support cgroup writeback.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f60de54d2042..f0520bcf2094 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -513,6 +513,11 @@ out_free: void wbc_attach_and_unlock_inode(struct writeback_control *wbc, struct inode *inode) { + if (!inode_cgwb_enabled(inode)) { + spin_unlock(&inode->i_lock); + return; + } + wbc->wb = inode_to_wb(inode); wbc->inode = inode; @@ -575,11 +580,16 @@ void wbc_detach_inode(struct writeback_control *wbc) { struct bdi_writeback *wb = wbc->wb; struct inode *inode = wbc->inode; - u16 history = inode->i_wb_frn_history; - unsigned long avg_time = inode->i_wb_frn_avg_time; - unsigned long max_bytes, max_time; + unsigned long avg_time, max_bytes, max_time; + u16 history; int max_id; + if (!wb) + return; + + history = inode->i_wb_frn_history; + avg_time = inode->i_wb_frn_avg_time; + /* pick the winner of this round */ if (wbc->wb_bytes >= wbc->wb_lcand_bytes && wbc->wb_bytes >= wbc->wb_tcand_bytes) { |