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authorMikulas Patocka <mpatocka@redhat.com>2020-02-24 10:20:31 +0100
committerMike Snitzer <snitzer@redhat.com>2020-03-24 16:26:18 +0100
commitd53f1fafec9d086f1c5166436abefdaef30e0363 (patch)
treed876e8292420f04d2c38ebf5defa92683fdcf982 /drivers/md
parentdm integrity: print device name in integrity_metadata() error message (diff)
downloadlinux-d53f1fafec9d086f1c5166436abefdaef30e0363.tar.xz
linux-d53f1fafec9d086f1c5166436abefdaef30e0363.zip
dm writecache: do direct write if the cache is full
If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-writecache.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index a09bdc000e64..dc1e10c6ecd7 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -1194,6 +1194,7 @@ read_next_block:
}
} else {
do {
+ bool found_entry = false;
if (writecache_has_error(wc))
goto unlock_error;
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, 0);
@@ -1204,9 +1205,21 @@ read_next_block:
wc->overwrote_committed = true;
goto bio_copy;
}
+ found_entry = true;
}
e = writecache_pop_from_freelist(wc, (sector_t)-1);
if (unlikely(!e)) {
+ if (!found_entry) {
+ e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING);
+ if (e) {
+ sector_t next_boundary = read_original_sector(wc, e) - bio->bi_iter.bi_sector;
+ BUG_ON(!next_boundary);
+ if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT) {
+ dm_accept_partial_bio(bio, next_boundary);
+ }
+ }
+ goto unlock_remap_origin;
+ }
writecache_wait_on_freelist(wc);
continue;
}