X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Ffs-writeback.c;h=9d5360c4c2afbe98d2b46112f131f90d943e00f5;hb=fb3165b59f9ce510fed07262db20fdb799f88fa6;hp=15e375bf93e6d4fbf1f4bb977d78c83a62a96f85;hpb=71fd05a887e0f3f6bfff76ff81b33776177d0606;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 15e375b..9d5360c 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -250,9 +250,11 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi, * completion. Caller need not hold sb s_umount semaphore. * */ -void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages) +void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, + long nr_pages) { struct wb_writeback_args args = { + .sb = sb, .sync_mode = WB_SYNC_NONE, .nr_pages = nr_pages, .range_cyclic = 1, @@ -320,7 +322,7 @@ static bool inode_dirtied_after(struct inode *inode, unsigned long t) * For inodes being constantly redirtied, dirtied_when can get stuck. * It _appears_ to be in the future, but is actually in distant past. * This test is necessary to prevent such wrapped-around relative times - * from permanently stopping the whole pdflush writeback. + * from permanently stopping the whole bdi writeback. */ ret = ret && time_before_eq(inode->dirtied_when, jiffies); #endif @@ -334,13 +336,38 @@ static void move_expired_inodes(struct list_head *delaying_queue, struct list_head *dispatch_queue, unsigned long *older_than_this) { + LIST_HEAD(tmp); + struct list_head *pos, *node; + struct super_block *sb = NULL; + struct inode *inode; + int do_sb_sort = 0; + while (!list_empty(delaying_queue)) { - struct inode *inode = list_entry(delaying_queue->prev, - struct inode, i_list); + inode = list_entry(delaying_queue->prev, struct inode, i_list); if (older_than_this && inode_dirtied_after(inode, *older_than_this)) break; - list_move(&inode->i_list, dispatch_queue); + if (sb && sb != inode->i_sb) + do_sb_sort = 1; + sb = inode->i_sb; + list_move(&inode->i_list, &tmp); + } + + /* just one sb in list, splice to dispatch_queue and we're done */ + if (!do_sb_sort) { + list_splice(&tmp, dispatch_queue); + return; + } + + /* Move inodes from one superblock together */ + while (!list_empty(&tmp)) { + inode = list_entry(tmp.prev, struct inode, i_list); + sb = inode->i_sb; + list_for_each_prev_safe(pos, node, &tmp) { + inode = list_entry(pos, struct inode, i_list); + if (inode->i_sb == sb) + list_move(&inode->i_list, dispatch_queue); + } } } @@ -449,10 +476,15 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) spin_lock(&inode_lock); inode->i_state &= ~I_SYNC; if (!(inode->i_state & (I_FREEING | I_CLEAR))) { - if (inode->i_state & I_DIRTY) { + if ((inode->i_state & I_DIRTY_PAGES) && wbc->for_kupdate) { + /* + * More pages get dirtied by a fast dirtier. + */ + goto select_queue; + } else if (inode->i_state & I_DIRTY) { /* - * Someone redirtied the inode while were writing back - * the pages. + * At least XFS will redirty the inode during the + * writeback (delalloc) and on io completion (isize). */ redirty_tail(inode); } else if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { @@ -477,6 +509,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * soon as the queue becomes uncongested. */ inode->i_state |= I_DIRTY_PAGES; +select_queue: if (wbc->nr_to_write <= 0) { /* * slice used up: queue for next turn @@ -515,6 +548,17 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) return ret; } +static void unpin_sb_for_writeback(struct super_block **psb) +{ + struct super_block *sb = *psb; + + if (sb) { + up_read(&sb->s_umount); + put_super(sb); + *psb = NULL; + } +} + /* * For WB_SYNC_NONE writeback, the caller does not have the sb pinned * before calling writeback. So make sure that we do pin it, so it doesn't @@ -524,11 +568,20 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * 1 if we failed. */ static int pin_sb_for_writeback(struct writeback_control *wbc, - struct inode *inode) + struct inode *inode, struct super_block **psb) { struct super_block *sb = inode->i_sb; /* + * If this sb is already pinned, nothing more to do. If not and + * *psb is non-NULL, unpin the old one first + */ + if (sb == *psb) + return 0; + else if (*psb) + unpin_sb_for_writeback(psb); + + /* * Caller must already hold the ref for this */ if (wbc->sync_mode == WB_SYNC_ALL) { @@ -541,7 +594,7 @@ static int pin_sb_for_writeback(struct writeback_control *wbc, if (down_read_trylock(&sb->s_umount)) { if (sb->s_root) { spin_unlock(&sb_lock); - return 0; + goto pinned; } /* * umounted, drop rwsem again and fall through to failure @@ -552,24 +605,15 @@ static int pin_sb_for_writeback(struct writeback_control *wbc, sb->s_count--; spin_unlock(&sb_lock); return 1; -} - -static void unpin_sb_for_writeback(struct writeback_control *wbc, - struct inode *inode) -{ - struct super_block *sb = inode->i_sb; - - if (wbc->sync_mode == WB_SYNC_ALL) - return; - - up_read(&sb->s_umount); - put_super(sb); +pinned: + *psb = sb; + return 0; } static void writeback_inodes_wb(struct bdi_writeback *wb, struct writeback_control *wbc) { - struct super_block *sb = wbc->sb; + struct super_block *sb = wbc->sb, *pin_sb = NULL; const int is_blkdev_sb = sb_is_blkdev_sb(sb); const unsigned long start = jiffies; /* livelock avoidance */ @@ -628,7 +672,7 @@ static void writeback_inodes_wb(struct bdi_writeback *wb, if (inode_dirtied_after(inode, start)) break; - if (pin_sb_for_writeback(wbc, inode)) { + if (pin_sb_for_writeback(wbc, inode, &pin_sb)) { requeue_io(inode); continue; } @@ -637,7 +681,6 @@ static void writeback_inodes_wb(struct bdi_writeback *wb, __iget(inode); pages_skipped = wbc->pages_skipped; writeback_single_inode(inode, wbc); - unpin_sb_for_writeback(wbc, inode); if (wbc->pages_skipped != pages_skipped) { /* * writeback is not making progress due to locked @@ -657,6 +700,8 @@ static void writeback_inodes_wb(struct bdi_writeback *wb, wbc->more_io = 1; } + unpin_sb_for_writeback(&pin_sb); + spin_unlock(&inode_lock); /* Leave any unwritten inodes on b_io */ } @@ -1085,9 +1130,6 @@ EXPORT_SYMBOL(__mark_inode_dirty); * If older_than_this is non-NULL, then only write out inodes which * had their first dirtying at a time earlier than *older_than_this. * - * If we're a pdlfush thread, then implement pdflush collision avoidance - * against the entire list. - * * If `bdi' is non-zero then we're being asked to writeback a specific queue. * This function assumes that the blockdev superblock's inodes are backed by * a variety of queues, so all inodes are searched. For other superblocks, @@ -1166,7 +1208,7 @@ void writeback_inodes_sb(struct super_block *sb) nr_to_write = nr_dirty + nr_unstable + (inodes_stat.nr_inodes - inodes_stat.nr_unused); - bdi_writeback_all(sb, nr_to_write); + bdi_start_writeback(sb->s_bdi, sb, nr_to_write); } EXPORT_SYMBOL(writeback_inodes_sb);