Re: [PATCH 5/7] affs: stop using lock_super

From: Jan Kara
Date: Wed Jun 06 2012 - 06:08:18 EST


On Tue 05-06-12 14:28:13, Artem Bityutskiy wrote:
> From: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
>
> The VFS's 'lock_super()' and 'unlock_super()' calls are deprecated and unwanted
> and just wait for a brave knight who'd kill them. This patch makes AFFS stop
> using them and introduces own AFFS superblock mutex which we use for
> serializeing the root block changes.
Hum, why not just use the buffer lock for this?

Honza
>
> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
> ---
> fs/affs/affs.h | 1 +
> fs/affs/super.c | 5 +++--
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/affs/affs.h b/fs/affs/affs.h
> index 45a0ce4..b8af745 100644
> --- a/fs/affs/affs.h
> +++ b/fs/affs/affs.h
> @@ -108,6 +108,7 @@ struct affs_sb_info {
> char *s_prefix; /* Prefix for volumes and assigns. */
> char s_volume[32]; /* Volume prefix for absolute symlinks. */
> spinlock_t symlink_lock; /* protects the previous two */
> + struct mutex s_lock; /* protects the SB's buffer-head */
> };
>
> #define SF_INTL 0x0001 /* International filesystem. */
> diff --git a/fs/affs/super.c b/fs/affs/super.c
> index 8293cb9..8674915 100644
> --- a/fs/affs/super.c
> +++ b/fs/affs/super.c
> @@ -31,14 +31,14 @@ affs_commit_super(struct super_block *sb, int wait)
> struct buffer_head *bh = sbi->s_root_bh;
> struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
>
> - lock_super(sb);
> + mutex_lock(&sbi->s_lock);
> tail->bm_flag = cpu_to_be32(2);
> secs_to_datestamp(get_seconds(), &tail->disk_change);
> affs_fix_checksum(sb, bh);
> mark_buffer_dirty(bh);
> if (wait)
> sync_dirty_buffer(bh);
> - unlock_super(sb);
> + mutex_unlock(&sbi->s_lock);
> }
>
> static void
> @@ -299,6 +299,7 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent)
> return -ENOMEM;
>
> sb->s_fs_info = sbi;
> + mutex_init(&sbi->s_lock);
> mutex_init(&sbi->s_bmlock);
> spin_lock_init(&sbi->symlink_lock);
>
> --
> 1.7.7.6
>
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--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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