diff options
| author |   Martijn Coenen <maco@android.com> | 2020-05-13 15:38:39 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-05-21 08:20:34 -0600 |
| commit | b0bd158dd630bd47640e0e418c062cda1e0da5ad (patch) | |
| tree | 0ed7aebddaf3dab09625f79240decb743f64abd0 /drivers/block | |
| parent | loop: Switch to set_capacity_revalidate_and_notify() (diff) | |
| download | wireguard-linux-b0bd158dd630bd47640e0e418c062cda1e0da5ad.tar.xz wireguard-linux-b0bd158dd630bd47640e0e418c062cda1e0da5ad.zip | |
loop: Refactor loop_set_status() size calculation
figure_loop_size() calculates the loop size based on the passed in
parameters, but at the same time it updates the offset and sizelimit
parameters in the loop device configuration. That is a somewhat
unexpected side effect of a function with this name, and it is only only
needed by one of the two callers of this function - loop_set_status().
Move the lo_offset and lo_sizelimit assignment back into loop_set_status(),
and use the newly factored out functions to validate and apply the newly
calculated size. This allows us to get rid of figure_loop_size() in a
follow-up commit.
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/loop.c | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index d9a756f8abd5..c134b3439483 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -250,11 +250,6 @@ figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) { loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); - if (lo->lo_offset != offset) - lo->lo_offset = offset; - if (lo->lo_sizelimit != sizelimit) - lo->lo_sizelimit = sizelimit; - loop_set_size(lo, size); } @@ -1272,6 +1267,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) kuid_t uid = current_uid(); struct block_device *bdev; bool partscan = false; + bool size_changed = false; err = mutex_lock_killable(&loop_ctl_mutex); if (err) @@ -1293,6 +1289,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) if (lo->lo_offset != info->lo_offset || lo->lo_sizelimit != info->lo_sizelimit) { + size_changed = true; sync_blockdev(lo->lo_device); kill_bdev(lo->lo_device); } @@ -1300,6 +1297,15 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) /* I/O need to be drained during transfer transition */ blk_mq_freeze_queue(lo->lo_queue); + if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { + /* If any pages were dirtied after kill_bdev(), try again */ + err = -EAGAIN; + pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", + __func__, lo->lo_number, lo->lo_file_name, + lo->lo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + err = loop_release_xfer(lo); if (err) goto out_unfreeze; @@ -1323,19 +1329,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) if (err) goto out_unfreeze; - if (lo->lo_offset != info->lo_offset || - lo->lo_sizelimit != info->lo_sizelimit) { - /* kill_bdev should have truncated all the pages */ - if (lo->lo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - figure_loop_size(lo, info->lo_offset, info->lo_sizelimit); - } - + lo->lo_offset = info->lo_offset; + lo->lo_sizelimit = info->lo_sizelimit; memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); lo->lo_file_name[LO_NAME_SIZE-1] = 0; @@ -1359,6 +1354,12 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) lo->lo_key_owner = uid; } + if (size_changed) { + loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit, + lo->lo_backing_file); + loop_set_size(lo, new_size); + } + loop_config_discard(lo); /* update dio if lo_offset or transfer is changed */ |