X-Git-Url: http://bbs.cooldavid.org/git/?a=blobdiff_plain;f=fs%2Ffs-writeback.c;h=3d06ccc953aafaa8f590528015953e2e53a2c0c9;hb=925d169f5b86fe57e2f5264ea574cce9a89b719d;hp=9e46aec10d1aaaec3a4f0fe968ebc99412f09713;hpb=766f9164193f6dda1497bbf3861060198421fb92;p=net-next-2.6.git diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 9e46aec10d1..3d06ccc953a 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -79,6 +79,11 @@ static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) return sb->s_bdi; } +static inline struct inode *wb_inode(struct list_head *head) +{ + return list_entry(head, struct inode, i_wb_list); +} + static void bdi_queue_work(struct backing_dev_info *bdi, struct wb_writeback_work *work) { @@ -172,11 +177,11 @@ static void redirty_tail(struct inode *inode) if (!list_empty(&wb->b_dirty)) { struct inode *tail; - tail = list_entry(wb->b_dirty.next, struct inode, i_list); + tail = wb_inode(wb->b_dirty.next); if (time_before(inode->dirtied_when, tail->dirtied_when)) inode->dirtied_when = jiffies; } - list_move(&inode->i_list, &wb->b_dirty); + list_move(&inode->i_wb_list, &wb->b_dirty); } /* @@ -186,7 +191,7 @@ static void requeue_io(struct inode *inode) { struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; - list_move(&inode->i_list, &wb->b_more_io); + list_move(&inode->i_wb_list, &wb->b_more_io); } static void inode_sync_complete(struct inode *inode) @@ -227,14 +232,14 @@ static void move_expired_inodes(struct list_head *delaying_queue, int do_sb_sort = 0; while (!list_empty(delaying_queue)) { - inode = list_entry(delaying_queue->prev, struct inode, i_list); + inode = wb_inode(delaying_queue->prev); if (older_than_this && inode_dirtied_after(inode, *older_than_this)) break; if (sb && sb != inode->i_sb) do_sb_sort = 1; sb = inode->i_sb; - list_move(&inode->i_list, &tmp); + list_move(&inode->i_wb_list, &tmp); } /* just one sb in list, splice to dispatch_queue and we're done */ @@ -245,12 +250,11 @@ static void move_expired_inodes(struct list_head *delaying_queue, /* Move inodes from one superblock together */ while (!list_empty(&tmp)) { - inode = list_entry(tmp.prev, struct inode, i_list); - sb = inode->i_sb; + sb = wb_inode(tmp.prev)->i_sb; list_for_each_prev_safe(pos, node, &tmp) { - inode = list_entry(pos, struct inode, i_list); + inode = wb_inode(pos); if (inode->i_sb == sb) - list_move(&inode->i_list, dispatch_queue); + list_move(&inode->i_wb_list, dispatch_queue); } } } @@ -408,16 +412,13 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * completion. */ redirty_tail(inode); - } else if (atomic_read(&inode->i_count)) { - /* - * The inode is clean, inuse - */ - list_move(&inode->i_list, &inode_in_use); } else { /* - * The inode is clean, unused + * The inode is clean. At this point we either have + * a reference to the inode or it's on it's way out. + * No need to add it back to the LRU. */ - list_move(&inode->i_list, &inode_unused); + list_del_init(&inode->i_wb_list); } } inode_sync_complete(inode); @@ -465,8 +466,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, { while (!list_empty(&wb->b_io)) { long pages_skipped; - struct inode *inode = list_entry(wb->b_io.prev, - struct inode, i_list); + struct inode *inode = wb_inode(wb->b_io.prev); if (inode->i_sb != sb) { if (only_this_sb) { @@ -487,10 +487,16 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, return 0; } - if (inode->i_state & (I_NEW | I_WILL_FREE)) { + /* + * Don't bother with new inodes or inodes beeing freed, first + * kind does not need peridic writeout yet, and for the latter + * kind writeout is handled by the freer. + */ + if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { requeue_io(inode); continue; } + /* * Was this inode dirtied after sync_sb_inodes was called? * This keeps sync from extra jobs and livelock. @@ -498,7 +504,6 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, if (inode_dirtied_after(inode, wbc->wb_start)) return 1; - BUG_ON(inode->i_state & I_FREEING); __iget(inode); pages_skipped = wbc->pages_skipped; writeback_single_inode(inode, wbc); @@ -536,8 +541,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb, queue_io(wb, wbc->older_than_this); while (!list_empty(&wb->b_io)) { - struct inode *inode = list_entry(wb->b_io.prev, - struct inode, i_list); + struct inode *inode = wb_inode(wb->b_io.prev); struct super_block *sb = inode->i_sb; if (!pin_sb_for_writeback(sb)) { @@ -675,8 +679,7 @@ static long wb_writeback(struct bdi_writeback *wb, */ spin_lock(&inode_lock); if (!list_empty(&wb->b_more_io)) { - inode = list_entry(wb->b_more_io.prev, - struct inode, i_list); + inode = wb_inode(wb->b_more_io.prev); trace_wbc_writeback_wait(&wbc, wb->bdi); inode_wait_for_writeback(inode); } @@ -704,6 +707,17 @@ get_next_work_item(struct backing_dev_info *bdi) return work; } +/* + * Add in the number of potentially dirty inodes, because each inode + * write can dirty pagecache in the underlying blockdev. + */ +static unsigned long get_nr_dirty_pages(void) +{ + return global_page_state(NR_FILE_DIRTY) + + global_page_state(NR_UNSTABLE_NFS) + + get_nr_dirty_inodes(); +} + static long wb_check_old_data_flush(struct bdi_writeback *wb) { unsigned long expired; @@ -721,13 +735,7 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb) return 0; wb->last_old_flush = jiffies; - /* - * Add in the number of potentially dirty inodes, because each inode - * write can dirty pagecache in the underlying blockdev. - */ - nr_pages = global_page_state(NR_FILE_DIRTY) + - global_page_state(NR_UNSTABLE_NFS) + - (inodes_stat.nr_inodes - inodes_stat.nr_unused); + nr_pages = get_nr_dirty_pages(); if (nr_pages) { struct wb_writeback_work work = { @@ -966,7 +974,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) * dirty list. Add blockdev inodes as well. */ if (!S_ISBLK(inode->i_mode)) { - if (hlist_unhashed(&inode->i_hash)) + if (inode_unhashed(inode)) goto out; } if (inode->i_state & I_FREEING) @@ -994,7 +1002,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) } inode->dirtied_when = jiffies; - list_move(&inode->i_list, &bdi->wb.b_dirty); + list_move(&inode->i_wb_list, &bdi->wb.b_dirty); } } out: @@ -1073,33 +1081,42 @@ static void wait_sb_inodes(struct super_block *sb) } /** - * writeback_inodes_sb - writeback dirty inodes from given super_block + * writeback_inodes_sb_nr - writeback dirty inodes from given super_block * @sb: the superblock + * @nr: the number of pages to write * * Start writeback on some inodes on this super_block. No guarantees are made * on how many (if any) will be written, and this function does not wait - * for IO completion of submitted IO. The number of pages submitted is - * returned. + * for IO completion of submitted IO. */ -void writeback_inodes_sb(struct super_block *sb) +void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr) { - unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); - unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); DECLARE_COMPLETION_ONSTACK(done); struct wb_writeback_work work = { .sb = sb, .sync_mode = WB_SYNC_NONE, .done = &done, + .nr_pages = nr, }; WARN_ON(!rwsem_is_locked(&sb->s_umount)); - - work.nr_pages = nr_dirty + nr_unstable + - (inodes_stat.nr_inodes - inodes_stat.nr_unused); - bdi_queue_work(sb->s_bdi, &work); wait_for_completion(&done); } +EXPORT_SYMBOL(writeback_inodes_sb_nr); + +/** + * writeback_inodes_sb - writeback dirty inodes from given super_block + * @sb: the superblock + * + * Start writeback on some inodes on this super_block. No guarantees are made + * on how many (if any) will be written, and this function does not wait + * for IO completion of submitted IO. + */ +void writeback_inodes_sb(struct super_block *sb) +{ + return writeback_inodes_sb_nr(sb, get_nr_dirty_pages()); +} EXPORT_SYMBOL(writeback_inodes_sb); /** @@ -1121,6 +1138,27 @@ int writeback_inodes_sb_if_idle(struct super_block *sb) } EXPORT_SYMBOL(writeback_inodes_sb_if_idle); +/** + * writeback_inodes_sb_if_idle - start writeback if none underway + * @sb: the superblock + * @nr: the number of pages to write + * + * Invoke writeback_inodes_sb if no writeback is currently underway. + * Returns 1 if writeback was started, 0 if not. + */ +int writeback_inodes_sb_nr_if_idle(struct super_block *sb, + unsigned long nr) +{ + if (!writeback_in_progress(sb->s_bdi)) { + down_read(&sb->s_umount); + writeback_inodes_sb_nr(sb, nr); + up_read(&sb->s_umount); + return 1; + } else + return 0; +} +EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle); + /** * sync_inodes_sb - sync sb inode pages * @sb: the superblock @@ -1202,3 +1240,23 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc) return ret; } EXPORT_SYMBOL(sync_inode); + +/** + * sync_inode - write an inode to disk + * @inode: the inode to sync + * @wait: wait for I/O to complete. + * + * Write an inode to disk and adjust it's dirty state after completion. + * + * Note: only writes the actual inode, no associated data or other metadata. + */ +int sync_inode_metadata(struct inode *inode, int wait) +{ + struct writeback_control wbc = { + .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, + .nr_to_write = 0, /* metadata-only */ + }; + + return sync_inode(inode, &wbc); +} +EXPORT_SYMBOL(sync_inode_metadata);