From 0e3c9a2284f5417f196e327c254d0b84c9ee8929 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 1 Jun 2010 11:08:43 +0200 Subject: [PATCH] Revert "writeback: fix WB_SYNC_NONE writeback from umount" This reverts commit e913fc825dc685a444cb4c1d0f9d32f372f59861. We are investigating a hang associated with the WB_SYNC_NONE changes, so revert them for now. Conflicts: fs/fs-writeback.c mm/page-writeback.c Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 48 +++++++++++---------------------------------- fs/sync.c | 2 +- include/linux/backing-dev.h | 2 +- include/linux/writeback.h | 10 ---------- mm/page-writeback.c | 4 ++-- 5 files changed, 15 insertions(+), 51 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 6753912..408a787 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -45,7 +45,6 @@ struct wb_writeback_args { unsigned int for_kupdate:1; unsigned int range_cyclic:1; unsigned int for_background:1; - unsigned int sb_pinned:1; }; /* @@ -231,11 +230,6 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi, .sync_mode = WB_SYNC_ALL, .nr_pages = LONG_MAX, .range_cyclic = 0, - /* - * Setting sb_pinned is not necessary for WB_SYNC_ALL, but - * lets make it explicitly clear. - */ - .sb_pinned = 1, }; struct bdi_work work; @@ -251,23 +245,21 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi, * @bdi: the backing device to write from * @sb: write inodes from this super_block * @nr_pages: the number of pages to write - * @sb_locked: caller already holds sb umount sem. * * Description: * This does WB_SYNC_NONE opportunistic writeback. The IO is only * started when this function returns, we make no guarentees on - * completion. Caller specifies whether sb umount sem is held already or not. + * completion. Caller need not hold sb s_umount semaphore. * */ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, - long nr_pages, int sb_locked) + long nr_pages) { struct wb_writeback_args args = { .sb = sb, .sync_mode = WB_SYNC_NONE, .nr_pages = nr_pages, .range_cyclic = 1, - .sb_pinned = sb_locked, }; /* @@ -592,7 +584,7 @@ static enum sb_pin_state pin_sb_for_writeback(struct writeback_control *wbc, /* * Caller must already hold the ref for this */ - if (wbc->sync_mode == WB_SYNC_ALL || wbc->sb_pinned) { + if (wbc->sync_mode == WB_SYNC_ALL) { WARN_ON(!rwsem_is_locked(&sb->s_umount)); return SB_NOT_PINNED; } @@ -766,7 +758,6 @@ static long wb_writeback(struct bdi_writeback *wb, .for_kupdate = args->for_kupdate, .for_background = args->for_background, .range_cyclic = args->range_cyclic, - .sb_pinned = args->sb_pinned, }; unsigned long oldest_jif; long wrote = 0; @@ -1214,18 +1205,6 @@ static void wait_sb_inodes(struct super_block *sb) iput(old_inode); } -static void __writeback_inodes_sb(struct super_block *sb, int sb_locked) -{ - unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); - unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); - long nr_to_write; - - nr_to_write = nr_dirty + nr_unstable + - (inodes_stat.nr_inodes - inodes_stat.nr_unused); - - bdi_start_writeback(sb->s_bdi, sb, nr_to_write, sb_locked); -} - /** * writeback_inodes_sb - writeback dirty inodes from given super_block * @sb: the superblock @@ -1237,21 +1216,16 @@ static void __writeback_inodes_sb(struct super_block *sb, int sb_locked) */ void writeback_inodes_sb(struct super_block *sb) { - __writeback_inodes_sb(sb, 0); -} -EXPORT_SYMBOL(writeback_inodes_sb); + unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); + unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); + long nr_to_write; -/** - * writeback_inodes_sb_locked - writeback dirty inodes from given super_block - * @sb: the superblock - * - * Like writeback_inodes_sb(), except the caller already holds the - * sb umount sem. - */ -void writeback_inodes_sb_locked(struct super_block *sb) -{ - __writeback_inodes_sb(sb, 1); + nr_to_write = nr_dirty + nr_unstable + + (inodes_stat.nr_inodes - inodes_stat.nr_unused); + + bdi_start_writeback(sb->s_bdi, sb, nr_to_write); } +EXPORT_SYMBOL(writeback_inodes_sb); /** * writeback_inodes_sb_if_idle - start writeback if none underway diff --git a/fs/sync.c b/fs/sync.c index e8cbd41..5a537cc 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -42,7 +42,7 @@ static int __sync_filesystem(struct super_block *sb, int wait) if (wait) sync_inodes_sb(sb); else - writeback_inodes_sb_locked(sb); + writeback_inodes_sb(sb); if (sb->s_op->sync_fs) sb->s_op->sync_fs(sb, wait); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index e6e0cb5..aee5f6c 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -106,7 +106,7 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); void bdi_unregister(struct backing_dev_info *bdi); int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int); void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, - long nr_pages, int sb_locked); + long nr_pages); int bdi_writeback_task(struct bdi_writeback *wb); int bdi_has_dirty_io(struct backing_dev_info *bdi); void bdi_arm_supers_timer(void); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index cc97d6c..f641346 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -65,15 +65,6 @@ struct writeback_control { * so we use a single control to update them */ unsigned no_nrwrite_index_update:1; - - /* - * For WB_SYNC_ALL, the sb must always be pinned. For WB_SYNC_NONE, - * the writeback code will pin the sb for the caller. However, - * for eg umount, the caller does WB_SYNC_NONE but already has - * the sb pinned. If the below is set, caller already has the - * sb pinned. - */ - unsigned sb_pinned:1; }; /* @@ -82,7 +73,6 @@ struct writeback_control { struct bdi_writeback; int inode_wait(void *); void writeback_inodes_sb(struct super_block *); -void writeback_inodes_sb_locked(struct super_block *); int writeback_inodes_sb_if_idle(struct super_block *); void sync_inodes_sb(struct super_block *); void writeback_inodes_wbc(struct writeback_control *wbc); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index b289310..5fa63bd 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping, (!laptop_mode && ((global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS)) > background_thresh))) - bdi_start_writeback(bdi, NULL, 0, 0); + bdi_start_writeback(bdi, NULL, 0); } void set_page_dirty_balance(struct page *page, int page_mkwrite) @@ -707,7 +707,7 @@ void laptop_mode_timer_fn(unsigned long data) */ if (bdi_has_dirty_io(&q->backing_dev_info)) - bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages, 0); + bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages); } /* -- 2.7.4