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From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-bcache@vger.kernel.org, Jan Kara <jack@suse.cz>,
	Mike Snitzer <snitzer@redhat.com>,
	linux-mm@kvack.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jan Kara <jack@suse.com>, Josef Bacik <josef@toxicpanda.com>,
	Coly Li <colyli@suse.de>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	dm-devel@redhat.com, linux-mtd@lists.infradead.org,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>,
	Tejun Heo <tj@kernel.org>
Subject: [dm-devel] [PATCH 17/44] init: refactor devt_from_partuuid
Date: Thu, 26 Nov 2020 14:03:55 +0100
Message-ID: <20201126130422.92945-18-hch@lst.de> (raw)
In-Reply-To: <20201126130422.92945-1-hch@lst.de>

The code in devt_from_partuuid is very convoluted.  Refactor a bit by
sanitizing the goto and variable name usage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
---
 init/do_mounts.c | 68 ++++++++++++++++++++++--------------------------
 1 file changed, 31 insertions(+), 37 deletions(-)

diff --git a/init/do_mounts.c b/init/do_mounts.c
index aef2f24461c7f1..afa26a4028d25e 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -105,13 +105,10 @@ static int match_dev_by_uuid(struct device *dev, const void *data)
  */
 static dev_t devt_from_partuuid(const char *uuid_str)
 {
-	dev_t res = 0;
 	struct uuidcmp cmp;
 	struct device *dev = NULL;
-	struct gendisk *disk;
-	struct hd_struct *part;
+	dev_t devt = 0;
 	int offset = 0;
-	bool clear_root_wait = false;
 	char *slash;
 
 	cmp.uuid = uuid_str;
@@ -120,52 +117,49 @@ static dev_t devt_from_partuuid(const char *uuid_str)
 	/* Check for optional partition number offset attributes. */
 	if (slash) {
 		char c = 0;
+
 		/* Explicitly fail on poor PARTUUID syntax. */
-		if (sscanf(slash + 1,
-			   "PARTNROFF=%d%c", &offset, &c) != 1) {
-			clear_root_wait = true;
-			goto done;
-		}
+		if (sscanf(slash + 1, "PARTNROFF=%d%c", &offset, &c) != 1)
+			goto clear_root_wait;
 		cmp.len = slash - uuid_str;
 	} else {
 		cmp.len = strlen(uuid_str);
 	}
 
-	if (!cmp.len) {
-		clear_root_wait = true;
-		goto done;
-	}
+	if (!cmp.len)
+		goto clear_root_wait;
 
-	dev = class_find_device(&block_class, NULL, &cmp,
-				&match_dev_by_uuid);
+	dev = class_find_device(&block_class, NULL, &cmp, &match_dev_by_uuid);
 	if (!dev)
-		goto done;
-
-	res = dev->devt;
+		return 0;
 
-	/* Attempt to find the partition by offset. */
-	if (!offset)
-		goto no_offset;
+	if (offset) {
+		/*
+		 * Attempt to find the requested partition by adding an offset
+		 * to the partition number found by UUID.
+		 */
+		struct hd_struct *part;
 
-	res = 0;
-	disk = part_to_disk(dev_to_part(dev));
-	part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
-	if (part) {
-		res = part_devt(part);
-		put_device(part_to_dev(part));
+		part = disk_get_part(dev_to_disk(dev),
+				     dev_to_part(dev)->partno + offset);
+		if (part) {
+			devt = part_devt(part);
+			put_device(part_to_dev(part));
+		}
+	} else {
+		devt = dev->devt;
 	}
 
-no_offset:
 	put_device(dev);
-done:
-	if (clear_root_wait) {
-		pr_err("VFS: PARTUUID= is invalid.\n"
-		       "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
-		if (root_wait)
-			pr_err("Disabling rootwait; root= is invalid.\n");
-		root_wait = 0;
-	}
-	return res;
+	return devt;
+
+clear_root_wait:
+	pr_err("VFS: PARTUUID= is invalid.\n"
+	       "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
+	if (root_wait)
+		pr_err("Disabling rootwait; root= is invalid.\n");
+	root_wait = 0;
+	return 0;
 }
 
 /**
-- 
2.29.2

--
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  parent reply index

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-26 13:03 [dm-devel] merge struct block_device and struct hd_struct v3 Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 01/44] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 02/44] filemap: consistently use ->f_mapping over ->i_mapping Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 03/44] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 04/44] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-26 14:13   ` Jan Kara
2020-11-26 13:03 ` [dm-devel] [PATCH 05/44] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 06/44] zram: do not call set_blocksize Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 07/44] loop: " Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 08/44] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 09/44] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-27 10:36   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 10/44] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-27 10:36   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 11/44] block: remove a superflous check in blkpg_do_ioctl Christoph Hellwig
2020-11-27 10:37   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 12/44] block: add a bdev_kobj helper Christoph Hellwig
2020-11-26 14:47   ` David Sterba
2020-11-27 12:03   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 13/44] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-27 12:04   ` Hannes Reinecke
2020-11-26 13:03 ` [dm-devel] [PATCH 14/44] block: use put_device in put_disk Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 15/44] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 16/44] init: refactor name_to_dev_t Christoph Hellwig
2020-11-26 13:03 ` Christoph Hellwig [this message]
2020-11-26 13:03 ` [dm-devel] [PATCH 18/44] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 19/44] block: refactor __blkdev_put Christoph Hellwig
2020-11-26 13:03 ` [dm-devel] [PATCH 20/44] block: refactor blkdev_get Christoph Hellwig
2020-11-26 14:55   ` Jan Kara
2020-11-26 13:03 ` [dm-devel] [PATCH 21/44] block: move bdput() to the callers of __blkdev_get Christoph Hellwig
2020-11-26 15:05   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 22/44] block: opencode devcgroup_inode_permission Christoph Hellwig
2020-11-26 15:07   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 23/44] block: remove i_bdev Christoph Hellwig
2020-11-26 15:45   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 24/44] block: simplify bdev/disk lookup in blkdev_get Christoph Hellwig
2020-11-26 16:33   ` Jan Kara
2020-11-26 17:42     ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 25/44] block: remove ->bd_contains Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 26/44] block: simplify the block device claiming interface Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 27/44] block: simplify part_to_disk Christoph Hellwig
2020-11-26 16:36   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 28/44] block: initialize struct block_device in bdev_alloc Christoph Hellwig
2020-11-26 16:37   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 29/44] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-26 16:50   ` Jan Kara
2020-11-26 17:52     ` Christoph Hellwig
2020-11-26 18:04       ` Jan Kara
2020-11-27  9:41         ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 30/44] block: move disk stat accounting to struct block_device Christoph Hellwig
2020-11-26 16:53   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 31/44] block: move the start_sect field " Christoph Hellwig
2020-11-26 16:56   ` Jan Kara
2020-11-26 18:02     ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 32/44] block: move the partition_meta_info " Christoph Hellwig
2020-11-26 16:58   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 33/44] block: move holder_dir " Christoph Hellwig
2020-11-26 17:00   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 34/44] block: move make_it_fail " Christoph Hellwig
2020-11-26 17:01   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 35/44] block: move the policy field " Christoph Hellwig
2020-11-26 17:03   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 36/44] block: allocate struct hd_struct as part of struct bdev_inode Christoph Hellwig
2020-11-26 17:35   ` Jan Kara
2020-11-26 18:00     ` Jan Kara
2020-11-26 18:02       ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 37/44] block: switch partition lookup to use struct block_device Christoph Hellwig
2020-11-26 17:45   ` Jan Kara
2020-11-26 18:22   ` Jan Kara
2020-11-27  9:48     ` Christoph Hellwig
2020-11-27 12:45       ` Jan Kara
2020-11-27 15:36         ` Christoph Hellwig
2020-11-27 17:26           ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 38/44] block: remove the partno field from struct hd_struct Christoph Hellwig
2020-11-26 17:46   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 39/44] block: pass a block_device to blk_alloc_devt Christoph Hellwig
2020-11-26 17:47   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 40/44] block: pass a block_device to invalidate_partition Christoph Hellwig
2020-11-26 17:49   ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 41/44] block: switch disk_part_iter_* to use a struct block_device Christoph Hellwig
2020-11-27 12:53   ` Jan Kara
2020-11-27 15:24     ` Christoph Hellwig
2020-11-27 17:30       ` Jan Kara
2020-11-26 13:04 ` [dm-devel] [PATCH 42/44] f2fs: remove a few bd_part checks Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 43/44] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-27 13:19   ` Jan Kara
2020-11-27 15:47     ` Christoph Hellwig
2020-11-26 13:04 ` [dm-devel] [PATCH 44/44] block: stop using bdget_disk for partition 0 Christoph Hellwig
2020-11-27 13:22   ` Jan Kara

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