From 208b14e507c00ff7f108e1a388dd3d8cc805a443 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 7 May 2012 19:02:46 +0300 Subject: [PATCH] jffs2: get rid of jffs2_sync_super 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 a delayed work. Instead of setting the 's_dirt' flag we just schedule a delayed work for synchronizing the write-buffer. Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- fs/jffs2/jffs2_fs_sb.h | 4 +++ fs/jffs2/os-linux.h | 7 ++---- fs/jffs2/super.c | 13 ---------- fs/jffs2/wbuf.c | 55 +++++++++++++++++++++++++++++++++++++++--- 4 files changed, 58 insertions(+), 21 deletions(-) diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h index 0d00bf26923b..413ef89c2d1b 100644 --- a/fs/jffs2/jffs2_fs_sb.h +++ b/fs/jffs2/jffs2_fs_sb.h @@ -133,6 +133,10 @@ struct jffs2_sb_info { struct jffs2_inodirty *wbuf_inodes; struct rw_semaphore wbuf_sem; /* Protects the write buffer */ + struct delayed_work wbuf_dwork; /* write-buffer write-out work */ + int wbuf_queued; /* non-zero delayed work is queued */ + spinlock_t wbuf_dwork_lock; /* protects wbuf_dwork and and wbuf_queued */ + unsigned char *oobbuf; int oobavail; /* How many bytes are available for JFFS2 in OOB */ #endif diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h index 1cd3aec9d9ae..bcd983d7e7f9 100644 --- a/fs/jffs2/os-linux.h +++ b/fs/jffs2/os-linux.h @@ -95,6 +95,7 @@ static inline void jffs2_init_inode_info(struct jffs2_inode_info *f) #define jffs2_ubivol(c) (0) #define jffs2_ubivol_setup(c) (0) #define jffs2_ubivol_cleanup(c) do {} while (0) +#define jffs2_dirty_trigger(c) do {} while (0) #else /* NAND and/or ECC'd NOR support present */ @@ -135,14 +136,10 @@ void jffs2_ubivol_cleanup(struct jffs2_sb_info *c); #define jffs2_nor_wbuf_flash(c) (c->mtd->type == MTD_NORFLASH && ! (c->mtd->flags & MTD_BIT_WRITEABLE)) int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c); void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c); +void jffs2_dirty_trigger(struct jffs2_sb_info *c); #endif /* WRITEBUFFER */ -static inline void jffs2_dirty_trigger(struct jffs2_sb_info *c) -{ - OFNI_BS_2SFFJ(c)->s_dirt = 1; -} - /* background.c */ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c); void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c); diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index b36aa950d2a6..61ea41389f90 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -63,18 +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); - - sb->s_dirt = 0; - - if (!(sb->s_flags & MS_RDONLY)) { - jffs2_dbg(1, "%s()\n", __func__); - jffs2_flush_wbuf_gc(c, 0); - } -} - static const char *jffs2_compr_name(unsigned int compr) { switch (compr) { @@ -263,7 +251,6 @@ static const struct super_operations jffs2_super_operations = .alloc_inode = jffs2_alloc_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, diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c index 74d9be19df3f..6f4529d3697f 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "nodelist.h" @@ -85,7 +86,7 @@ static void jffs2_wbuf_dirties_inode(struct jffs2_sb_info *c, uint32_t ino) { struct jffs2_inodirty *new; - /* Mark the superblock dirty so that kupdated will flush... */ + /* Schedule delayed write-buffer write-out */ jffs2_dirty_trigger(c); if (jffs2_wbuf_pending_for_ino(c, ino)) @@ -1148,6 +1149,47 @@ int jffs2_write_nand_badblock(struct jffs2_sb_info *c, struct jffs2_eraseblock * return 1; } +static struct jffs2_sb_info *work_to_sb(struct work_struct *work) +{ + struct delayed_work *dwork; + + dwork = container_of(work, struct delayed_work, work); + return container_of(dwork, struct jffs2_sb_info, wbuf_dwork); +} + +static void delayed_wbuf_sync(struct work_struct *work) +{ + struct jffs2_sb_info *c = work_to_sb(work); + struct super_block *sb = OFNI_BS_2SFFJ(c); + + spin_lock(&c->wbuf_dwork_lock); + c->wbuf_queued = 0; + spin_unlock(&c->wbuf_dwork_lock); + + if (!(sb->s_flags & MS_RDONLY)) { + jffs2_dbg(1, "%s()\n", __func__); + jffs2_flush_wbuf_gc(c, 0); + } +} + +void jffs2_dirty_trigger(struct jffs2_sb_info *c) +{ + struct super_block *sb = OFNI_BS_2SFFJ(c); + unsigned long delay; + + if (sb->s_flags & MS_RDONLY) + return; + + spin_lock(&c->wbuf_dwork_lock); + if (!c->wbuf_queued) { + jffs2_dbg(1, "%s()\n", __func__); + delay = msecs_to_jiffies(dirty_writeback_interval * 10); + queue_delayed_work(system_long_wq, &c->wbuf_dwork, delay); + c->wbuf_queued = 1; + } + spin_unlock(&c->wbuf_dwork_lock); +} + int jffs2_nand_flash_setup(struct jffs2_sb_info *c) { struct nand_ecclayout *oinfo = c->mtd->ecclayout; @@ -1169,6 +1211,8 @@ int jffs2_nand_flash_setup(struct jffs2_sb_info *c) /* Initialise write buffer */ init_rwsem(&c->wbuf_sem); + spin_lock_init(&c->wbuf_dwork_lock); + INIT_DELAYED_WORK(&c->wbuf_dwork, delayed_wbuf_sync); c->wbuf_pagesize = c->mtd->writesize; c->wbuf_ofs = 0xFFFFFFFF; @@ -1207,8 +1251,8 @@ int jffs2_dataflash_setup(struct jffs2_sb_info *c) { /* Initialize write buffer */ init_rwsem(&c->wbuf_sem); - - + spin_lock_init(&c->wbuf_dwork_lock); + INIT_DELAYED_WORK(&c->wbuf_dwork, delayed_wbuf_sync); c->wbuf_pagesize = c->mtd->erasesize; /* Find a suitable c->sector_size @@ -1267,6 +1311,9 @@ int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c) { /* Initialize write buffer */ init_rwsem(&c->wbuf_sem); + spin_lock_init(&c->wbuf_dwork_lock); + INIT_DELAYED_WORK(&c->wbuf_dwork, delayed_wbuf_sync); + c->wbuf_pagesize = c->mtd->writesize; c->wbuf_ofs = 0xFFFFFFFF; @@ -1299,6 +1346,8 @@ int jffs2_ubivol_setup(struct jffs2_sb_info *c) { return 0; init_rwsem(&c->wbuf_sem); + spin_lock_init(&c->wbuf_dwork_lock); + INIT_DELAYED_WORK(&c->wbuf_dwork, delayed_wbuf_sync); c->wbuf_pagesize = c->mtd->writesize; c->wbuf_ofs = 0xFFFFFFFF;