From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-bcache@vger.kernel.org, Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, Mike Snitzer <snitzer@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
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, Richard Weinberger <richard@nod.at>,
dm-devel@redhat.com, linux-mtd@lists.infradead.org,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Tejun Heo <tj@kernel.org>,
xen-devel@lists.xenproject.org, linux-mm@kvack.org
Subject: [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev
Date: Tue, 24 Nov 2020 14:27:10 +0100 [thread overview]
Message-ID: <20201124132751.3747337-5-hch@lst.de> (raw)
In-Reply-To: <20201124132751.3747337-1-hch@lst.de>
Store the frozen superblock in struct block_device to avoid the awkward
interface that can return a sb only used a cookie, an ERR_PTR or NULL.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/dm-core.h | 5 -----
drivers/md/dm.c | 20 ++++++--------------
fs/block_dev.c | 39 ++++++++++++++++-----------------------
fs/buffer.c | 2 +-
fs/ext4/ioctl.c | 2 +-
fs/f2fs/file.c | 14 +++++---------
fs/xfs/xfs_fsops.c | 7 ++-----
include/linux/blk_types.h | 1 +
include/linux/blkdev.h | 4 ++--
9 files changed, 34 insertions(+), 60 deletions(-)
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index d522093cb39dda..aace147effcacb 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -96,11 +96,6 @@ struct mapped_device {
*/
struct workqueue_struct *wq;
- /*
- * freeze/thaw support require holding onto a super block
- */
- struct super_block *frozen_sb;
-
/* forced geometry settings */
struct hd_geometry geometry;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 54739f1b579bc8..50541d336c719b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2392,27 +2392,19 @@ static int lock_fs(struct mapped_device *md)
{
int r;
- WARN_ON(md->frozen_sb);
+ WARN_ON(test_bit(DMF_FROZEN, &md->flags));
- md->frozen_sb = freeze_bdev(md->bdev);
- if (IS_ERR(md->frozen_sb)) {
- r = PTR_ERR(md->frozen_sb);
- md->frozen_sb = NULL;
- return r;
- }
-
- set_bit(DMF_FROZEN, &md->flags);
-
- return 0;
+ r = freeze_bdev(md->bdev);
+ if (!r)
+ set_bit(DMF_FROZEN, &md->flags);
+ return r;
}
static void unlock_fs(struct mapped_device *md)
{
if (!test_bit(DMF_FROZEN, &md->flags))
return;
-
- thaw_bdev(md->bdev, md->frozen_sb);
- md->frozen_sb = NULL;
+ thaw_bdev(md->bdev);
clear_bit(DMF_FROZEN, &md->flags);
}
diff --git a/fs/block_dev.c b/fs/block_dev.c
index d8664f5c1ff669..60492620d51866 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -548,55 +548,47 @@ EXPORT_SYMBOL(fsync_bdev);
* count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
* actually.
*/
-struct super_block *freeze_bdev(struct block_device *bdev)
+int freeze_bdev(struct block_device *bdev)
{
struct super_block *sb;
int error = 0;
mutex_lock(&bdev->bd_fsfreeze_mutex);
- if (++bdev->bd_fsfreeze_count > 1) {
- /*
- * We don't even need to grab a reference - the first call
- * to freeze_bdev grab an active reference and only the last
- * thaw_bdev drops it.
- */
- sb = get_super(bdev);
- if (sb)
- drop_super(sb);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return sb;
- }
+ if (++bdev->bd_fsfreeze_count > 1)
+ goto done;
sb = get_active_super(bdev);
if (!sb)
- goto out;
+ goto sync;
if (sb->s_op->freeze_super)
error = sb->s_op->freeze_super(sb);
else
error = freeze_super(sb);
+ deactivate_super(sb);
+
if (error) {
- deactivate_super(sb);
bdev->bd_fsfreeze_count--;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return ERR_PTR(error);
+ goto done;
}
- deactivate_super(sb);
- out:
+ bdev->bd_fsfreeze_sb = sb;
+
+sync:
sync_blockdev(bdev);
+done:
mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return sb; /* thaw_bdev releases s->s_umount */
+ return error; /* thaw_bdev releases s->s_umount */
}
EXPORT_SYMBOL(freeze_bdev);
/**
* thaw_bdev -- unlock filesystem
* @bdev: blockdevice to unlock
- * @sb: associated superblock
*
* Unlocks the filesystem and marks it writeable again after freeze_bdev().
*/
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
+int thaw_bdev(struct block_device *bdev)
{
+ struct super_block *sb;
int error = -EINVAL;
mutex_lock(&bdev->bd_fsfreeze_mutex);
@@ -607,6 +599,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
if (--bdev->bd_fsfreeze_count > 0)
goto out;
+ sb = bdev->bd_fsfreeze_sb;
if (!sb)
goto out;
@@ -618,7 +611,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
bdev->bd_fsfreeze_count++;
out:
mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return error;
+ return 0;
}
EXPORT_SYMBOL(thaw_bdev);
diff --git a/fs/buffer.c b/fs/buffer.c
index 23f645657488ba..a7595ada9400ff 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -523,7 +523,7 @@ static int osync_buffers_list(spinlock_t *lock, struct list_head *list)
void emergency_thaw_bdev(struct super_block *sb)
{
- while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
+ while (sb->s_bdev && !thaw_bdev(sb->s_bdev))
printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev);
}
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index f0381876a7e5b0..524e134324475e 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -624,7 +624,7 @@ static int ext4_shutdown(struct super_block *sb, unsigned long arg)
case EXT4_GOING_FLAGS_DEFAULT:
freeze_bdev(sb->s_bdev);
set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
- thaw_bdev(sb->s_bdev, sb);
+ thaw_bdev(sb->s_bdev);
break;
case EXT4_GOING_FLAGS_LOGFLUSH:
set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ee861c6d9ff026..a9fc482a0e60a5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2230,16 +2230,12 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
switch (in) {
case F2FS_GOING_DOWN_FULLSYNC:
- sb = freeze_bdev(sb->s_bdev);
- if (IS_ERR(sb)) {
- ret = PTR_ERR(sb);
+ ret = freeze_bdev(sb->s_bdev);
+ if (ret)
goto out;
- }
- if (sb) {
- f2fs_stop_checkpoint(sbi, false);
- set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
- thaw_bdev(sb->s_bdev, sb);
- }
+ f2fs_stop_checkpoint(sbi, false);
+ set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
+ thaw_bdev(sb->s_bdev);
break;
case F2FS_GOING_DOWN_METASYNC:
/* do checkpoint only */
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index ef1d5bb88b93ab..b7c5783a031c69 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -433,13 +433,10 @@ xfs_fs_goingdown(
{
switch (inflags) {
case XFS_FSOP_GOING_FLAGS_DEFAULT: {
- struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
-
- if (sb && !IS_ERR(sb)) {
+ if (!freeze_bdev(mp->m_super->s_bdev)) {
xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
- thaw_bdev(sb->s_bdev, sb);
+ thaw_bdev(mp->m_super->s_bdev);
}
-
break;
}
case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index d9b69bbde5cc54..ebfb4e7c1fd125 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -46,6 +46,7 @@ struct block_device {
int bd_fsfreeze_count;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
+ struct super_block *bd_fsfreeze_sb;
} __randomize_layout;
/*
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 05b346a68c2eee..12810a19edebc4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -2020,7 +2020,7 @@ static inline int sync_blockdev(struct block_device *bdev)
#endif
int fsync_bdev(struct block_device *bdev);
-struct super_block *freeze_bdev(struct block_device *bdev);
-int thaw_bdev(struct block_device *bdev, struct super_block *sb);
+int freeze_bdev(struct block_device *bdev);
+int thaw_bdev(struct block_device *bdev);
#endif /* _LINUX_BLKDEV_H */
--
2.29.2
--
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dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel
next prev parent reply other threads:[~2020-11-24 13:33 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 13:27 [dm-devel] merge struct block_device and struct hd_struct v2 Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 01/45] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-25 6:41 ` Hannes Reinecke
2020-11-24 13:27 ` [dm-devel] [PATCH 02/45] filemap: consistently use ->f_mapping over ->i_mapping Christoph Hellwig
2020-11-24 13:53 ` Matthew Wilcox
2020-11-25 6:41 ` Hannes Reinecke
2020-11-25 12:16 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 03/45] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
2020-11-25 6:42 ` Hannes Reinecke
2020-11-25 12:19 ` Jan Kara
2020-11-24 13:27 ` Christoph Hellwig [this message]
2020-11-25 6:07 ` [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Chao Yu
2020-11-25 12:29 ` Jan Kara
2020-11-25 16:22 ` Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 05/45] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-25 12:31 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 06/45] zram: remove the claim mechanism Christoph Hellwig
2020-11-25 12:37 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 07/45] zram: do not call set_blocksize Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 08/45] loop: " Christoph Hellwig
2020-11-25 13:37 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 09/45] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 10/45] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 11/45] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-24 17:36 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 12/45] block: remove a superflous check in blkpg_do_ioctl Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-25 13:39 ` Jan Kara
2020-11-24 13:27 ` [dm-devel] [PATCH 13/45] block: add a bdev_kobj helper Christoph Hellwig
2020-11-24 13:41 ` Coly Li
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 14/45] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 15/45] block: use put_device in put_disk Christoph Hellwig
2020-11-24 17:37 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 16/45] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 17/45] init: refactor name_to_dev_t Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 18/45] init: refactor devt_from_partuuid Christoph Hellwig
2020-11-24 17:38 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 19/45] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-24 17:39 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 20/45] block: refactor __blkdev_put Christoph Hellwig
2020-11-24 17:41 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 21/45] block: refactor blkdev_get Christoph Hellwig
2020-11-24 18:03 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 22/45] block: opencode devcgroup_inode_permission Christoph Hellwig
2020-11-24 18:05 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 23/45] block: remove i_bdev Christoph Hellwig
2020-11-24 13:38 ` Coly Li
2020-11-24 19:37 ` Tejun Heo
2020-11-25 16:29 ` Christoph Hellwig
2020-11-25 20:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 24/45] blk-cgroup: stop abusing get_gendisk Christoph Hellwig
2020-11-24 19:46 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 25/45] block: reference struct block_device from struct hd_struct Christoph Hellwig
2020-11-24 21:18 ` Tejun Heo
2020-11-25 16:45 ` Christoph Hellwig
2020-11-25 20:20 ` Tejun Heo
2020-11-26 8:16 ` Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 26/45] block: remove ->bd_contains Christoph Hellwig
2020-11-24 21:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 27/45] block: simplify the block device claiming interface Christoph Hellwig
2020-11-24 21:19 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 28/45] block: simplify part_to_disk Christoph Hellwig
2020-11-24 21:20 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 29/45] block: initialize struct block_device in bdev_alloc Christoph Hellwig
2020-11-24 21:20 ` Tejun Heo
2020-11-24 13:27 ` [dm-devel] [PATCH 30/45] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-24 13:34 ` Coly Li
2020-11-25 6:10 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 31/45] block: move disk stat accounting to struct block_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 32/45] block: move the start_sect field " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 33/45] block: move the partition_meta_info " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 34/45] block: move holder_dir " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 35/45] block: move make_it_fail " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 36/45] block: move the policy field " Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 37/45] block: allocate struct hd_struct as part of struct bdev_inode Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 38/45] block: switch partition lookup to use struct block_device Christoph Hellwig
2020-11-24 13:32 ` Coly Li
2020-11-25 6:11 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 39/45] block: remove the partno field from struct hd_struct Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 40/45] block: pass a block_device to blk_alloc_devt Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 41/45] block: pass a block_device to invalidate_partition Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 42/45] block: switch disk_part_iter_* to use a struct block_device Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 43/45] f2fs: remove a few bd_part checks Christoph Hellwig
2020-11-25 6:12 ` Chao Yu
2020-11-24 13:27 ` [dm-devel] [PATCH 44/45] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-24 13:27 ` [dm-devel] [PATCH 45/45] block: stop using bdget_disk for partition 0 Christoph Hellwig
2020-11-28 16:14 [dm-devel] merge struct block_device and struct hd_struct v4 Christoph Hellwig
2020-11-28 16:14 ` [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-30 17:55 ` Darrick J. Wong
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