From 3dd847820d138c9d60764b0e920380373285ff10 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Wed, 6 Jun 2012 18:56:57 +0300 Subject: [PATCH] affs: get rid of affs_sync_super This patch makes affs stop using the VFS '->write_super()' method along with the 's_dirt' superblock flag, because they are on their way out. The whole "superblock write-out" VFS infrastructure is served by the 'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and writes out all dirty superblocks using the '->write_super()' call-back. But the problem with this thread is that it wastes power by waking up the system every 5 seconds, even if there are no diry superblocks, or there are no client file-systems which would need this (e.g., btrfs does not use '->write_super()'). So we want to kill it completely and thus, we need to make file-systems to stop using the '->write_super()' VFS service, and then remove it together with the kernel thread. Signed-off-by: Artem Bityutskiy Signed-off-by: Al Viro --- fs/affs/affs.h | 6 ++++++ fs/affs/bitmap.c | 4 ++-- fs/affs/super.c | 48 +++++++++++++++++++++++++++++++++++++----------- 3 files changed, 45 insertions(+), 13 deletions(-) diff --git a/fs/affs/affs.h b/fs/affs/affs.h index 5a726e9..3a130e2 100644 --- a/fs/affs/affs.h +++ b/fs/affs/affs.h @@ -3,6 +3,7 @@ #include #include #include +#include /* AmigaOS allows file names with up to 30 characters length. * Names longer than that will be silently truncated. If you @@ -101,6 +102,9 @@ struct affs_sb_info { char s_volume[32]; /* Volume prefix for absolute symlinks. */ spinlock_t symlink_lock; /* protects the previous two */ struct super_block *sb; /* the VFS superblock object */ + int work_queued; /* non-zero delayed work is queued */ + struct delayed_work sb_work; /* superblock flush delayed work */ + spinlock_t work_lock; /* protects sb_work and work_queued */ }; #define SF_INTL 0x0001 /* International filesystem. */ @@ -121,6 +125,8 @@ static inline struct affs_sb_info *AFFS_SB(struct super_block *sb) return sb->s_fs_info; } +void affs_mark_sb_dirty(struct super_block *sb); + /* amigaffs.c */ extern int affs_insert_hash(struct inode *inode, struct buffer_head *bh); diff --git a/fs/affs/bitmap.c b/fs/affs/bitmap.c index 3e26271..6e0be43 100644 --- a/fs/affs/bitmap.c +++ b/fs/affs/bitmap.c @@ -103,7 +103,7 @@ affs_free_block(struct super_block *sb, u32 block) *(__be32 *)bh->b_data = cpu_to_be32(tmp - mask); mark_buffer_dirty(bh); - sb->s_dirt = 1; + affs_mark_sb_dirty(sb); bm->bm_free++; mutex_unlock(&sbi->s_bmlock); @@ -248,7 +248,7 @@ find_bit: *(__be32 *)bh->b_data = cpu_to_be32(tmp + mask); mark_buffer_dirty(bh); - sb->s_dirt = 1; + affs_mark_sb_dirty(sb); mutex_unlock(&sbi->s_bmlock); diff --git a/fs/affs/super.c b/fs/affs/super.c index 0496cbb..c70f1e5 100644 --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "affs.h" extern struct timezone sys_tz; @@ -47,6 +48,7 @@ affs_put_super(struct super_block *sb) struct affs_sb_info *sbi = AFFS_SB(sb); pr_debug("AFFS: put_super()\n"); + cancel_delayed_work_sync(&sbi->sb_work); kfree(sbi->s_prefix); affs_free_bitmap(sb); affs_brelse(sbi->s_root_bh); @@ -54,23 +56,45 @@ affs_put_super(struct super_block *sb) sb->s_fs_info = NULL; } -static void -affs_write_super(struct super_block *sb) -{ - if (!(sb->s_flags & MS_RDONLY)) - affs_commit_super(sb, 1); - sb->s_dirt = 0; - pr_debug("AFFS: write_super() at %lu, clean=2\n", get_seconds()); -} - static int affs_sync_fs(struct super_block *sb, int wait) { affs_commit_super(sb, wait); - sb->s_dirt = 0; return 0; } +static void flush_superblock(struct work_struct *work) +{ + struct affs_sb_info *sbi; + struct super_block *sb; + + sbi = container_of(work, struct affs_sb_info, sb_work.work); + sb = sbi->sb; + + spin_lock(&sbi->work_lock); + sbi->work_queued = 0; + spin_unlock(&sbi->work_lock); + + affs_commit_super(sb, 1); +} + +void affs_mark_sb_dirty(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + unsigned long delay; + + if (sb->s_flags & MS_RDONLY) + return; + + spin_lock(&sbi->work_lock); + if (!sbi->work_queued) { + delay = msecs_to_jiffies(dirty_writeback_interval * 10); + queue_delayed_work(system_long_wq, &sbi->sb_work, delay); + sbi->work_queued = 1; + } + spin_unlock(&sbi->work_lock); +} + static struct kmem_cache * affs_inode_cachep; static struct inode *affs_alloc_inode(struct super_block *sb) @@ -132,7 +156,6 @@ static const struct super_operations affs_sops = { .write_inode = affs_write_inode, .evict_inode = affs_evict_inode, .put_super = affs_put_super, - .write_super = affs_write_super, .sync_fs = affs_sync_fs, .statfs = affs_statfs, .remount_fs = affs_remount, @@ -302,6 +325,8 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent) sbi->sb = sb; mutex_init(&sbi->s_bmlock); spin_lock_init(&sbi->symlink_lock); + spin_lock_init(&sbi->work_lock); + INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, &blocksize,&sbi->s_prefix, @@ -526,6 +551,7 @@ affs_remount(struct super_block *sb, int *flags, char *data) return -EINVAL; } + flush_delayed_work_sync(&sbi->sb_work); replace_mount_options(sb, new_opts); sbi->s_flags = mount_flags; -- 2.7.4