iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dm snapshot: introduce account_start_copy() and account_end_copy()

Browse Source 
[ Upstream commit a2f83e8b0c82c9500421a26c49eb198b25fcdea3 ]

This simple refactoring moves code for modifying the semaphore cow_count
into separate functions to prepare for changes that will extend these
methods to provide for a more sophisticated mechanism for COW
throttling.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mikulas Patocka 2019-10-02 06:14:17 -04:00 committed by Greg Kroah-Hartman
parent 0685a2565a
commit 5de1e3a9e9
1 changed files with 13 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/md/dm-snap.c
View File

@ -1399,6 +1399,16 @@ static void snapshot_dtr(struct dm_target *ti)
kfree(s);
}
static void account_start_copy(struct dm_snapshot *s)
{
down(&s->cow_count);
}
static void account_end_copy(struct dm_snapshot *s)
{
up(&s->cow_count);
}
/*
* Flush a list of buffers.
*/
@ -1581,7 +1591,7 @@ static void copy_callback(int read_err, unsigned long write_err, void *context)
}
list_add(&pe->out_of_order_entry, lh);
}
up(&s->cow_count);
account_end_copy(s);
}
/*
@ -1605,7 +1615,7 @@ static void start_copy(struct dm_snap_pending_exception *pe)
dest.count = src.count;
/* Hand over to kcopyd */
down(&s->cow_count);
account_start_copy(s);
dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, copy_callback, pe);
}
@ -1625,7 +1635,7 @@ static void start_full_bio(struct dm_snap_pending_exception *pe,
pe->full_bio = bio;
pe->full_bio_end_io = bio->bi_end_io;
down(&s->cow_count);
account_start_copy(s);
callback_data = dm_kcopyd_prepare_callback(s->kcopyd_client,
copy_callback, pe);