Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759299Ab2EDR0V (ORCPT ); Fri, 4 May 2012 13:26:21 -0400 Received: from mga02.intel.com ([134.134.136.20]:21168 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759278Ab2EDR0T (ORCPT ); Fri, 4 May 2012 13:26:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="140179751" From: Artem Bityutskiy To: David Woodhouse , MTD Maling List Cc: Linux Kernel Maling List , Artem Bityutskiy Subject: [PATCH 2/2] jffs2: get rid of jffs2_sync_super Date: Fri, 4 May 2012 20:27:08 +0300 Message-Id: <1336152428-24242-3-git-send-email-dedekind1@gmail.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1336152428-24242-1-git-send-email-dedekind1@gmail.com> References: <1336152428-24242-1-git-send-email-dedekind1@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4732 Lines: 141 From: Artem Bityutskiy Currently JFFS2 file-system maps the VFS "superblock" abstraction to the write-buffer. Namely, it uses VFS services to synchronize the write-buffer periodically. 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 superblock 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 no matter what. 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. This patch switches the JFFS2 write-buffer management from '->write_super()'/'->s_dirt' to 'wbuf_inode'/'->write_inode'. Instead of setting the 's_dirt' flag, we just mark the special 'wbuf_inode' inode as dirty and let VFS invoke the '->write_inode' call-back when needed, where we synchronize the write-buffer. Signed-off-by: Artem Bityutskiy --- fs/jffs2/fs.c | 18 ++++++++++++++++++ fs/jffs2/os-linux.h | 3 ++- fs/jffs2/super.c | 22 +--------------------- 3 files changed, 21 insertions(+), 22 deletions(-) diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 94016a9..c6aacbb 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -228,6 +228,24 @@ int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } +int jffs2_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); + + /* + * JFFS2 is synchronous file-system, and the only the fake write-buffer + * inode is allowed to be writen-out asynchronously - we use this to do + * delayed write-buffer synchronization. + */ + BUG_ON(inode != c->wbuf_inode); + + if (!(inode->i_sb->s_flags & MS_RDONLY)) { + jffs2_dbg(1, "%s()\n", __func__); + jffs2_flush_wbuf_gc(c, 0); + } + + return 0; +} void jffs2_evict_inode (struct inode *inode) { diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h index 6f28cc5..ab97e88 100644 --- a/fs/jffs2/os-linux.h +++ b/fs/jffs2/os-linux.h @@ -144,7 +144,7 @@ void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c); static inline void jffs2_dirty_trigger(struct jffs2_sb_info *c) { - OFNI_BS_2SFFJ(c)->s_dirt = 1; + __mark_inode_dirty(c->wbuf_inode, I_DIRTY_SYNC); } /* background.c */ @@ -173,6 +173,7 @@ extern const struct inode_operations jffs2_symlink_inode_operations; int jffs2_setattr (struct dentry *, struct iattr *); int jffs2_do_setattr (struct inode *, struct iattr *); struct inode *jffs2_iget(struct super_block *, unsigned long); +int jffs2_write_inode(struct inode *inode, struct writeback_control *wbc); void jffs2_evict_inode (struct inode *); void jffs2_dirty_inode(struct inode *inode, int flags); struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index a180409..0b4e632 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -63,21 +63,6 @@ static void jffs2_i_init_once(void *foo) inode_init_once(&f->vfs_inode); } -static void jffs2_write_super(struct super_block *sb) -{ - struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); - - lock_super(sb); - sb->s_dirt = 0; - - if (!(sb->s_flags & MS_RDONLY)) { - jffs2_dbg(1, "%s()\n", __func__); - jffs2_flush_wbuf_gc(c, 0); - } - - unlock_super(sb); -} - static const char *jffs2_compr_name(unsigned int compr) { switch (compr) { @@ -113,8 +98,6 @@ static int jffs2_sync_fs(struct super_block *sb, int wait) { struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); - jffs2_write_super(sb); - mutex_lock(&c->alloc_sem); jffs2_flush_wbuf_pad(c); mutex_unlock(&c->alloc_sem); @@ -249,9 +232,9 @@ static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) static const struct super_operations jffs2_super_operations = { .alloc_inode = jffs2_alloc_inode, + .write_inode = jffs2_write_inode, .destroy_inode =jffs2_destroy_inode, .put_super = jffs2_put_super, - .write_super = jffs2_write_super, .statfs = jffs2_statfs, .remount_fs = jffs2_remount_fs, .evict_inode = jffs2_evict_inode, @@ -319,9 +302,6 @@ static void jffs2_put_super (struct super_block *sb) jffs2_dbg(2, "%s()\n", __func__); - if (sb->s_dirt) - jffs2_write_super(sb); - mutex_lock(&c->alloc_sem); jffs2_flush_wbuf_pad(c); mutex_unlock(&c->alloc_sem); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/