[PATCH 3/4] loop: Add 'lo_logical_blocksize'

From: Hannes Reinecke
Date: Mon Oct 31 2016 - 15:38:15 EST


Add a new field 'lo_logical_blocksize' to hold the logical
blocksize of the loop device.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/block/loop.c | 9 +++++++--
drivers/block/loop.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ff5c874..a863667 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -233,8 +233,11 @@ figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
lo->lo_offset = offset;
if (lo->lo_sizelimit != sizelimit)
lo->lo_sizelimit = sizelimit;
- if (lo->lo_flags & LO_FLAGS_BLOCKSIZE)
+ if (lo->lo_flags & LO_FLAGS_BLOCKSIZE) {
blk_queue_physical_block_size(lo->lo_queue, lo->lo_blocksize);
+ blk_queue_logical_block_size(lo->lo_queue,
+ lo->lo_logical_blocksize);
+ }
set_capacity(lo->lo_disk, x);
bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9);
/* let user-space know about the new size */
@@ -816,6 +819,7 @@ static void loop_config_discard(struct loop_device *lo)
struct file *file = lo->lo_backing_file;
struct inode *inode = file->f_mapping->host;
struct request_queue *q = lo->lo_queue;
+ int lo_bits = blksize_bits(lo->lo_logical_blocksize);

/*
* We use punch hole to reclaim the free space used by the
@@ -835,7 +839,7 @@ static void loop_config_discard(struct loop_device *lo)

q->limits.discard_granularity = inode->i_sb->s_blocksize;
q->limits.discard_alignment = 0;
- blk_queue_max_discard_sectors(q, UINT_MAX >> 9);
+ blk_queue_max_discard_sectors(q, UINT_MAX >> lo_bits);
q->limits.discard_zeroes_data = 1;
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
}
@@ -924,6 +928,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,

lo->use_dio = false;
lo->lo_blocksize = lo_blocksize;
+ lo->lo_logical_blocksize = 512;
lo->lo_device = bdev;
lo->lo_flags = lo_flags;
lo->lo_backing_file = file;
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index fb2237c..579f2f7 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -49,6 +49,7 @@ struct loop_device {
struct file * lo_backing_file;
struct block_device *lo_device;
unsigned lo_blocksize;
+ unsigned lo_logical_blocksize;
void *key_data;

gfp_t old_gfp_mask;
--
2.6.6