diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2016-08-30 22:20:55 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-08-30 22:20:55 +0200 |
| commit | 7efb367320f56fc4d549875b6f3a6940018ef2e5 (patch) | |
| tree | 6ae70b11607351484bb3218b684b062d64b76c4f | |
| parent | dm log writes: move IO accounting earlier to fix error path (diff) | |
| download | linux-7efb367320f56fc4d549875b6f3a6940018ef2e5.tar.xz linux-7efb367320f56fc4d549875b6f3a6940018ef2e5.zip | |
dm log writes: fix bug with too large bios
bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector
entries. However, the incoming bio may have more vector entries if it
was allocated by other means. For example, bcache submits bios with
more than BIO_MAX_PAGES entries. This results in bio_alloc() failure.
To avoid the failure, change the code so that it allocates bio with at
most BIO_MAX_PAGES entries. If the incoming bio has more entries,
bio_add_page() will fail and a new bio will be allocated - the code that
handles bio_add_page() failure already exists in the dm-log-writes
target.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Josef Bacik <jbacik@fb,com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v4.1+
| -rw-r--r-- | drivers/md/dm-log-writes.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c index 4cc78aef9007..ba24f4f37efc 100644 --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -260,7 +260,7 @@ static int log_one_block(struct log_writes_c *lc, sector++; atomic_inc(&lc->io_blocks); - bio = bio_alloc(GFP_KERNEL, block->vec_cnt); + bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; @@ -282,7 +282,7 @@ static int log_one_block(struct log_writes_c *lc, if (ret != block->vecs[i].bv_len) { atomic_inc(&lc->io_blocks); submit_bio(bio); - bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i); + bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; |