diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-06-01 11:44:45 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-06-05 10:53:03 -0600 |
| commit | ae5f855ead6b41422ca0c971ebda509c0414f8ec (patch) | |
| tree | 69db0b8d640254dfc4214988593395b48dc2a57e /block | |
| parent | 0783b1a7cbd9a02ddc35fe531b5966b674b304f0 (diff) | |
block: refactor bd_may_claim
The long if/else chain obsfucates the actual logic. Tidy it up to be
more structured. Also drop the whole argument, as it can be trivially
derived from bdev using bdev_whole, and having the bdev_whole in the
function makes it easier to follow.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bdev.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/block/bdev.c b/block/bdev.c index 317bfd9cba40..080b5c83bfbc 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -463,7 +463,6 @@ long nr_blockdev_pages(void) /** * bd_may_claim - test whether a block device can be claimed * @bdev: block device of interest - * @whole: whole block device containing @bdev, may equal @bdev * @holder: holder trying to claim @bdev * * Test whether @bdev can be claimed by @holder. @@ -474,22 +473,27 @@ long nr_blockdev_pages(void) * RETURNS: * %true if @bdev can be claimed, %false otherwise. */ -static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, - void *holder) +static bool bd_may_claim(struct block_device *bdev, void *holder) { - if (bdev->bd_holder == holder) - return true; /* already a holder */ - else if (bdev->bd_holder != NULL) - return false; /* held by someone else */ - else if (whole == bdev) - return true; /* is a whole device which isn't held */ - - else if (whole->bd_holder == bd_may_claim) - return true; /* is a partition of a device that is being partitioned */ - else if (whole->bd_holder != NULL) - return false; /* is a partition of a held device */ - else - return true; /* is a partition of an un-held device */ + struct block_device *whole = bdev_whole(bdev); + + if (bdev->bd_holder) { + /* + * The same holder can always re-claim. + */ + if (bdev->bd_holder == holder) + return true; + return false; + } + + /* + * If the whole devices holder is set to bd_may_claim, a partition on + * the device is claimed, but not the whole device. + */ + if (whole != bdev && + whole->bd_holder && whole->bd_holder != bd_may_claim) + return false; + return true; } /** @@ -513,7 +517,7 @@ int bd_prepare_to_claim(struct block_device *bdev, void *holder) retry: spin_lock(&bdev_lock); /* if someone else claimed, fail */ - if (!bd_may_claim(bdev, whole, holder)) { + if (!bd_may_claim(bdev, holder)) { spin_unlock(&bdev_lock); return -EBUSY; } @@ -559,7 +563,7 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder) struct block_device *whole = bdev_whole(bdev); spin_lock(&bdev_lock); - BUG_ON(!bd_may_claim(bdev, whole, holder)); + BUG_ON(!bd_may_claim(bdev, holder)); /* * Note that for a whole device bd_holders will be incremented twice, * and bd_holder will be set to bd_may_claim before being set to holder |