summaryrefslogtreecommitdiff
path: root/drivers/block/loop.c
diff options
context:
space:
mode:
authorHannes Reinecke <hare@suse.de>2017-06-08 14:46:45 +0300
committerJens Axboe <axboe@fb.com>2017-06-08 17:40:00 +0300
commitf2c6df7dbf9a60e1cd9941f9fb376d4d9ad1e8dd (patch)
tree79a9c0d9627fa253955532d6925e9606e1643f72 /drivers/block/loop.c
parent51001b7da364a24ed2464f3c22179efdc6b3a960 (diff)
downloadlinux-f2c6df7dbf9a60e1cd9941f9fb376d4d9ad1e8dd.tar.xz
loop: support 4k physical blocksize
When generating bootable VM images certain systems (most notably s390x) require devices with 4k blocksize. This patch implements a new flag 'LO_FLAGS_BLOCKSIZE' which will set the physical blocksize to that of the underlying device, and allow to change the logical blocksize for up to the physical blocksize. Signed-off-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c43
1 files changed, 37 insertions, 6 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index fc706adff6a4..4d376c10a97a 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -221,7 +221,8 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
}
static int
-figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
+figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit,
+ loff_t logical_blocksize)
{
loff_t size = get_size(offset, sizelimit, lo->lo_backing_file);
sector_t x = (sector_t)size;
@@ -233,6 +234,12 @@ 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) {
+ lo->lo_logical_blocksize = logical_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 */
@@ -810,6 +817,7 @@ 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 = 9;
/*
* We use punch hole to reclaim the free space used by the
@@ -829,8 +837,11 @@ 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_write_zeroes_sectors(q, UINT_MAX >> 9);
+ if (lo->lo_flags & LO_FLAGS_BLOCKSIZE)
+ lo_bits = blksize_bits(lo->lo_logical_blocksize);
+
+ blk_queue_max_discard_sectors(q, UINT_MAX >> lo_bits);
+ blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> lo_bits);
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
}
@@ -918,6 +929,7 @@ 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;
@@ -1083,6 +1095,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
int err;
struct loop_func_table *xfer;
kuid_t uid = current_uid();
+ int lo_flags = lo->lo_flags;
if (lo->lo_encrypt_key_size &&
!uid_eq(lo->lo_key_owner, uid) &&
@@ -1115,9 +1128,26 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
if (err)
goto exit;
+ if (info->lo_flags & LO_FLAGS_BLOCKSIZE) {
+ if (!(lo->lo_flags & LO_FLAGS_BLOCKSIZE))
+ lo->lo_logical_blocksize = 512;
+ lo->lo_flags |= LO_FLAGS_BLOCKSIZE;
+ if (LO_INFO_BLOCKSIZE(info) != 512 &&
+ LO_INFO_BLOCKSIZE(info) != 1024 &&
+ LO_INFO_BLOCKSIZE(info) != 2048 &&
+ LO_INFO_BLOCKSIZE(info) != 4096)
+ return -EINVAL;
+ if (LO_INFO_BLOCKSIZE(info) > lo->lo_blocksize)
+ return -EINVAL;
+ }
+
if (lo->lo_offset != info->lo_offset ||
- lo->lo_sizelimit != info->lo_sizelimit)
- if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) {
+ lo->lo_sizelimit != info->lo_sizelimit ||
+ lo->lo_flags != lo_flags ||
+ ((lo->lo_flags & LO_FLAGS_BLOCKSIZE) &&
+ lo->lo_logical_blocksize != LO_INFO_BLOCKSIZE(info))) {
+ if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit,
+ LO_INFO_BLOCKSIZE(info)))
err = -EFBIG;
goto exit;
}
@@ -1308,7 +1338,8 @@ static int loop_set_capacity(struct loop_device *lo)
if (unlikely(lo->lo_state != Lo_bound))
return -ENXIO;
- return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit);
+ return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit,
+ lo->lo_logical_blocksize);
}
static int loop_set_dio(struct loop_device *lo, unsigned long arg)