提交 2913808e 编写于 作者: M Mikulas Patocka 提交者: Alasdair G Kergon

dm snapshot: refactor __find_pending_exception

Move looking-up of a pending exception from __find_pending_exception to another
function.

Cc: stable@kernel.org
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
上级 b64b6bf4
......@@ -972,6 +972,17 @@ static void start_copy(struct dm_snap_pending_exception *pe)
&src, 1, &dest, 0, copy_callback, pe);
}
static struct dm_snap_pending_exception *
__lookup_pending_exception(struct dm_snapshot *s, chunk_t chunk)
{
struct dm_snap_exception *e = lookup_exception(&s->pending, chunk);
if (!e)
return NULL;
return container_of(e, struct dm_snap_pending_exception, e);
}
/*
* Looks to see if this snapshot already has a pending exception
* for this chunk, otherwise it allocates a new one and inserts
......@@ -983,20 +994,9 @@ static void start_copy(struct dm_snap_pending_exception *pe)
static struct dm_snap_pending_exception *
__find_pending_exception(struct dm_snapshot *s, struct bio *bio)
{
struct dm_snap_exception *e;
struct dm_snap_pending_exception *pe;
struct dm_snap_pending_exception *pe, *pe2;
chunk_t chunk = sector_to_chunk(s, bio->bi_sector);
/*
* Is there a pending exception for this already ?
*/
e = lookup_exception(&s->pending, chunk);
if (e) {
/* cast the exception to a pending exception */
pe = container_of(e, struct dm_snap_pending_exception, e);
goto out;
}
/*
* Create a new pending exception, we don't want
* to hold the lock while we do this.
......@@ -1010,11 +1010,10 @@ __find_pending_exception(struct dm_snapshot *s, struct bio *bio)
return NULL;
}
e = lookup_exception(&s->pending, chunk);
if (e) {
pe2 = __lookup_pending_exception(s, chunk);
if (pe2) {
free_pending_exception(pe);
pe = container_of(e, struct dm_snap_pending_exception, e);
goto out;
return pe2;
}
pe->e.old_chunk = chunk;
......@@ -1032,7 +1031,6 @@ __find_pending_exception(struct dm_snapshot *s, struct bio *bio)
get_pending_exception(pe);
insert_exception(&s->pending, &pe->e);
out:
return pe;
}
......@@ -1083,11 +1081,14 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
* writeable.
*/
if (bio_rw(bio) == WRITE) {
pe = __find_pending_exception(s, bio);
pe = __lookup_pending_exception(s, chunk);
if (!pe) {
__invalidate_snapshot(s, -ENOMEM);
r = -EIO;
goto out_unlock;
pe = __find_pending_exception(s, bio);
if (!pe) {
__invalidate_snapshot(s, -ENOMEM);
r = -EIO;
goto out_unlock;
}
}
remap_exception(s, &pe->e, bio, chunk);
......@@ -1217,10 +1218,13 @@ static int __origin_write(struct list_head *snapshots, struct bio *bio)
if (e)
goto next_snapshot;
pe = __find_pending_exception(snap, bio);
pe = __lookup_pending_exception(snap, chunk);
if (!pe) {
__invalidate_snapshot(snap, -ENOMEM);
goto next_snapshot;
pe = __find_pending_exception(snap, bio);
if (!pe) {
__invalidate_snapshot(snap, -ENOMEM);
goto next_snapshot;
}
}
if (!primary_pe) {
......
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