From: Jan Kara <jack@suse.cz>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, 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-bcache@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [dm-devel] [PATCH 03/45] fs: remove get_super_thawed and get_super_exclusive_thawed
Date: Wed, 25 Nov 2020 13:19:10 +0100 [thread overview]
Message-ID: <20201125121910.GG16944@quack2.suse.cz> (raw)
In-Reply-To: <20201124132751.3747337-4-hch@lst.de>
On Tue 24-11-20 14:27:09, Christoph Hellwig wrote:
> Just open code the wait in the only caller of both functions.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Fine by me. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/internal.h | 2 ++
> fs/quota/quota.c | 31 +++++++++++++++++++++-------
> fs/super.c | 51 ++--------------------------------------------
> include/linux/fs.h | 4 +---
> 4 files changed, 29 insertions(+), 59 deletions(-)
>
> diff --git a/fs/internal.h b/fs/internal.h
> index a7cd0f64faa4ab..47be21dfeebef5 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -114,7 +114,9 @@ extern struct file *alloc_empty_file_noaccount(int, const struct cred *);
> */
> extern int reconfigure_super(struct fs_context *);
> extern bool trylock_super(struct super_block *sb);
> +struct super_block *__get_super(struct block_device *bdev, bool excl);
> extern struct super_block *user_get_super(dev_t);
> +void put_super(struct super_block *sb);
> extern bool mount_capable(struct fs_context *);
>
> /*
> diff --git a/fs/quota/quota.c b/fs/quota/quota.c
> index 9af95c7a0bbe3c..f3d32b0d9008f2 100644
> --- a/fs/quota/quota.c
> +++ b/fs/quota/quota.c
> @@ -20,6 +20,7 @@
> #include <linux/writeback.h>
> #include <linux/nospec.h>
> #include "compat.h"
> +#include "../internal.h"
>
> static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
> qid_t id)
> @@ -868,6 +869,7 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
> struct block_device *bdev;
> struct super_block *sb;
> struct filename *tmp = getname(special);
> + bool excl = false, thawed = false;
>
> if (IS_ERR(tmp))
> return ERR_CAST(tmp);
> @@ -875,17 +877,32 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
> putname(tmp);
> if (IS_ERR(bdev))
> return ERR_CAST(bdev);
> - if (quotactl_cmd_onoff(cmd))
> - sb = get_super_exclusive_thawed(bdev);
> - else if (quotactl_cmd_write(cmd))
> - sb = get_super_thawed(bdev);
> - else
> - sb = get_super(bdev);
> +
> + if (quotactl_cmd_onoff(cmd)) {
> + excl = true;
> + thawed = true;
> + } else if (quotactl_cmd_write(cmd)) {
> + thawed = true;
> + }
> +
> +retry:
> + sb = __get_super(bdev, excl);
> + if (thawed && sb && sb->s_writers.frozen != SB_UNFROZEN) {
> + if (excl)
> + up_write(&sb->s_umount);
> + else
> + up_read(&sb->s_umount);
> + wait_event(sb->s_writers.wait_unfrozen,
> + sb->s_writers.frozen == SB_UNFROZEN);
> + put_super(sb);
> + goto retry;
> + }
> +
> bdput(bdev);
> if (!sb)
> return ERR_PTR(-ENODEV);
> -
> return sb;
> +
> #else
> return ERR_PTR(-ENODEV);
> #endif
> diff --git a/fs/super.c b/fs/super.c
> index 98bb0629ee108e..343e5c1e538d2a 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -307,7 +307,7 @@ static void __put_super(struct super_block *s)
> * Drops a temporary reference, frees superblock if there's no
> * references left.
> */
> -static void put_super(struct super_block *sb)
> +void put_super(struct super_block *sb)
> {
> spin_lock(&sb_lock);
> __put_super(sb);
> @@ -740,7 +740,7 @@ void iterate_supers_type(struct file_system_type *type,
>
> EXPORT_SYMBOL(iterate_supers_type);
>
> -static struct super_block *__get_super(struct block_device *bdev, bool excl)
> +struct super_block *__get_super(struct block_device *bdev, bool excl)
> {
> struct super_block *sb;
>
> @@ -789,53 +789,6 @@ struct super_block *get_super(struct block_device *bdev)
> }
> EXPORT_SYMBOL(get_super);
>
> -static struct super_block *__get_super_thawed(struct block_device *bdev,
> - bool excl)
> -{
> - while (1) {
> - struct super_block *s = __get_super(bdev, excl);
> - if (!s || s->s_writers.frozen == SB_UNFROZEN)
> - return s;
> - if (!excl)
> - up_read(&s->s_umount);
> - else
> - up_write(&s->s_umount);
> - wait_event(s->s_writers.wait_unfrozen,
> - s->s_writers.frozen == SB_UNFROZEN);
> - put_super(s);
> - }
> -}
> -
> -/**
> - * get_super_thawed - get thawed superblock of a device
> - * @bdev: device to get the superblock for
> - *
> - * Scans the superblock list and finds the superblock of the file system
> - * mounted on the device. The superblock is returned once it is thawed
> - * (or immediately if it was not frozen). %NULL is returned if no match
> - * is found.
> - */
> -struct super_block *get_super_thawed(struct block_device *bdev)
> -{
> - return __get_super_thawed(bdev, false);
> -}
> -EXPORT_SYMBOL(get_super_thawed);
> -
> -/**
> - * get_super_exclusive_thawed - get thawed superblock of a device
> - * @bdev: device to get the superblock for
> - *
> - * Scans the superblock list and finds the superblock of the file system
> - * mounted on the device. The superblock is returned once it is thawed
> - * (or immediately if it was not frozen) and s_umount semaphore is held
> - * in exclusive mode. %NULL is returned if no match is found.
> - */
> -struct super_block *get_super_exclusive_thawed(struct block_device *bdev)
> -{
> - return __get_super_thawed(bdev, true);
> -}
> -EXPORT_SYMBOL(get_super_exclusive_thawed);
> -
> /**
> * get_active_super - get an active reference to the superblock of a device
> * @bdev: device to get the superblock for
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 8667d0cdc71e76..a61df0dd4f1989 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1409,7 +1409,7 @@ enum {
>
> struct sb_writers {
> int frozen; /* Is sb frozen? */
> - wait_queue_head_t wait_unfrozen; /* for get_super_thawed() */
> + wait_queue_head_t wait_unfrozen; /* wait for thaw */
> struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
> };
>
> @@ -3132,8 +3132,6 @@ extern struct file_system_type *get_filesystem(struct file_system_type *fs);
> extern void put_filesystem(struct file_system_type *fs);
> extern struct file_system_type *get_fs_type(const char *name);
> extern struct super_block *get_super(struct block_device *);
> -extern struct super_block *get_super_thawed(struct block_device *);
> -extern struct super_block *get_super_exclusive_thawed(struct block_device *bdev);
> extern struct super_block *get_active_super(struct block_device *bdev);
> extern void drop_super(struct super_block *sb);
> extern void drop_super_exclusive(struct super_block *sb);
> --
> 2.29.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
--
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next prev parent reply other threads:[~2020-11-25 13:53 UTC|newest]
Thread overview: 91+ 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 [this message]
2020-11-24 13:27 ` [dm-devel] [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Christoph Hellwig
2020-11-25 6:07 ` 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 03/45] fs: remove get_super_thawed and get_super_exclusive_thawed Christoph Hellwig
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