X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Ffs-writeback.c;h=ea8592b906968913499b9847f35389a31e5dc1a3;hb=06df277a670263a073362046855851aad278d988;hp=4b37f7cea4dd28edac895ebbe9017d80e7031c16;hpb=03e62303cf56e87337115f14842321043df2b4bb;p=firefly-linux-kernel-4.4.55.git diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 4b37f7cea4dd..ea8592b90696 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -42,9 +42,10 @@ struct wb_writeback_args { long nr_pages; struct super_block *sb; enum writeback_sync_modes sync_mode; - int for_kupdate:1; - int range_cyclic:1; - int for_background:1; + unsigned int for_kupdate:1; + unsigned int range_cyclic:1; + unsigned int for_background:1; + unsigned int sb_pinned:1; }; /* @@ -192,7 +193,8 @@ static void bdi_wait_on_work_clear(struct bdi_work *work) } static void bdi_alloc_queue_work(struct backing_dev_info *bdi, - struct wb_writeback_args *args) + struct wb_writeback_args *args, + int wait) { struct bdi_work *work; @@ -204,6 +206,8 @@ static void bdi_alloc_queue_work(struct backing_dev_info *bdi, if (work) { bdi_work_init(work, args); bdi_queue_work(bdi, work); + if (wait) + bdi_wait_on_work_clear(work); } else { struct bdi_writeback *wb = &bdi->wb; @@ -230,6 +234,11 @@ 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; @@ -245,21 +254,23 @@ 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 need not hold sb s_umount semaphore. + * completion. Caller specifies whether sb umount sem is held already or not. * */ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, - long nr_pages) + long nr_pages, int sb_locked) { struct wb_writeback_args args = { .sb = sb, .sync_mode = WB_SYNC_NONE, .nr_pages = nr_pages, .range_cyclic = 1, + .sb_pinned = sb_locked, }; /* @@ -271,7 +282,7 @@ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, args.for_background = 1; } - bdi_alloc_queue_work(bdi, &args); + bdi_alloc_queue_work(bdi, &args, sb_locked); } /* @@ -398,11 +409,11 @@ static void inode_wait_for_writeback(struct inode *inode) wait_queue_head_t *wqh; wqh = bit_waitqueue(&inode->i_state, __I_SYNC); - do { + while (inode->i_state & I_SYNC) { spin_unlock(&inode_lock); __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); spin_lock(&inode_lock); - } while (inode->i_state & I_SYNC); + } } /* @@ -452,11 +463,9 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) BUG_ON(inode->i_state & I_SYNC); - /* Set I_SYNC, reset I_DIRTY */ - dirty = inode->i_state & I_DIRTY; + /* Set I_SYNC, reset I_DIRTY_PAGES */ inode->i_state |= I_SYNC; - inode->i_state &= ~I_DIRTY; - + inode->i_state &= ~I_DIRTY_PAGES; spin_unlock(&inode_lock); ret = do_writepages(mapping, wbc); @@ -472,6 +481,15 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) ret = err; } + /* + * Some filesystems may redirty the inode during the writeback + * due to delalloc, clear dirty metadata flags right before + * write_inode() + */ + spin_lock(&inode_lock); + dirty = inode->i_state & I_DIRTY; + inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); + spin_unlock(&inode_lock); /* Don't write the inode if only I_DIRTY_PAGES was set */ if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { int err = write_inode(inode, wbc); @@ -577,7 +595,7 @@ 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) { + if (wbc->sync_mode == WB_SYNC_ALL || wbc->sb_pinned) { WARN_ON(!rwsem_is_locked(&sb->s_umount)); return SB_NOT_PINNED; } @@ -751,6 +769,7 @@ 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; @@ -852,6 +871,12 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb) unsigned long expired; long nr_pages; + /* + * When set to zero, disable periodic writeback + */ + if (!dirty_writeback_interval) + return 0; + expired = wb->last_old_flush + msecs_to_jiffies(dirty_writeback_interval * 10); if (time_before(jiffies, expired)) @@ -887,6 +912,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait) while ((work = get_next_work_item(bdi, wb)) != NULL) { struct wb_writeback_args args = work->args; + int post_clear; /* * Override sync mode, in case we must wait for completion @@ -894,11 +920,13 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait) if (force_wait) work->args.sync_mode = args.sync_mode = WB_SYNC_ALL; + post_clear = WB_SYNC_ALL || args.sb_pinned; + /* * If this isn't a data integrity operation, just notify * that we have seen this work and we are now starting it. */ - if (args.sync_mode == WB_SYNC_NONE) + if (!post_clear) wb_clear_pending(wb, work); wrote += wb_writeback(wb, &args); @@ -907,7 +935,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait) * This is a data integrity writeback, so only do the * notification when we have completed the work. */ - if (args.sync_mode == WB_SYNC_ALL) + if (post_clear) wb_clear_pending(wb, work); } @@ -947,8 +975,17 @@ int bdi_writeback_task(struct bdi_writeback *wb) break; } - wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10); - schedule_timeout_interruptible(wait_jiffies); + if (dirty_writeback_interval) { + wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10); + schedule_timeout_interruptible(wait_jiffies); + } else { + set_current_state(TASK_INTERRUPTIBLE); + if (list_empty_careful(&wb->bdi->work_list) && + !kthread_should_stop()) + schedule(); + __set_current_state(TASK_RUNNING); + } + try_to_freeze(); } @@ -974,7 +1011,7 @@ static void bdi_writeback_all(struct super_block *sb, long nr_pages) if (!bdi_has_dirty_io(bdi)) continue; - bdi_alloc_queue_work(bdi, &args); + bdi_alloc_queue_work(bdi, &args, 0); } rcu_read_unlock(); @@ -1183,6 +1220,18 @@ 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 @@ -1194,17 +1243,22 @@ static void wait_sb_inodes(struct super_block *sb) */ void writeback_inodes_sb(struct super_block *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; - - 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); + __writeback_inodes_sb(sb, 0); } EXPORT_SYMBOL(writeback_inodes_sb); +/** + * 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); +} + /** * writeback_inodes_sb_if_idle - start writeback if none underway * @sb: the superblock