Btrfs: Transaction commit: don't use filemap_fdatawait

After writing out all the remaining btree blocks in the transaction,
the commit code would use filemap_fdatawait to make sure it was all
on disk.  This means it would wait for blocks written by other procs
as well.

The new code walks the list of blocks for this transaction again
and waits only for those required by this transaction.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9902d29abd06883a4ca35c499d0b2c4bd88c0c2c..9601b13c7d7a9486c814f176104520090610d425 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -429,7 +429,7 @@ int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
        return 0;
 }
 
-static int congested_async(struct btrfs_fs_info *info, int iodone)
+int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
 {
        int limit = 256 * info->fs_devices->open_devices;
 
@@ -438,9 +438,6 @@ static int congested_async(struct btrfs_fs_info *info, int iodone)
        if (atomic_read(&info->nr_async_submits) > limit)
                return 1;
 
-       limit = 8192 * info->fs_devices->open_devices;
-       if (iodone)
-               limit = (limit * 3) / 2;
        return atomic_read(&info->nr_async_bios) > limit;
 }
 
@@ -454,7 +451,7 @@ static void run_one_async_submit(struct btrfs_work *work)
        atomic_dec(&fs_info->nr_async_submits);
 
        if ((async->bio->bi_rw & (1 << BIO_RW)) &&
-           !congested_async(fs_info, 1)) {
+           !btrfs_congested_async(fs_info, 1)) {
                clear_bdi_congested(&fs_info->bdi, WRITE);
        }
        async->submit_bio_hook(async->inode, async->rw, async->bio,
@@ -963,7 +960,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
        struct backing_dev_info *bdi;
 
        if ((bdi_bits & (1 << BDI_write_congested)) &&
-           congested_async(info, 0))
+           btrfs_congested_async(info, 0))
                return 1;
 
        list_for_each(cur, &info->fs_devices->devices) {
@@ -1844,7 +1841,7 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
        struct extent_io_tree *tree;
        u64 num_dirty;
        u64 start = 0;
-       unsigned long thresh = 16 * 1024 * 1024;
+       unsigned long thresh = 2 * 1024 * 1024;
        tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 
        if (current_is_pdflush())

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 353c3c50c95758c4779de92c57fc94538689d741..e904a69347a41e5b22cf1b308014d10a1299cd42 100644 (file)
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -72,4 +72,5 @@ int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                        int rw, struct bio *bio, int mirror_num,
                        extent_submit_bio_hook_t *submit_bio_hook);
+int btrfs_congested_async(struct btrfs_fs_info *info, int iodone);
 #endif

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 9d3d08e9f8d172e6ac061d7efa962ffdc38ef0d6..6bcb0876f9bbca78a0c009a81c803ce9f2b27401 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -303,12 +303,12 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
                                     struct btrfs_root *root)
 {
        int ret;
-       int err;
+       int err = 0;
        int werr = 0;
        struct extent_io_tree *dirty_pages;
        struct page *page;
        struct inode *btree_inode = root->fs_info->btree_inode;
-       u64 start;
+       u64 start = 0;
        u64 end;
        unsigned long index;
 
@@ -317,12 +317,15 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
        }
        dirty_pages = &trans->transaction->dirty_pages;
        while(1) {
-               ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
+               ret = find_first_extent_bit(dirty_pages, start, &start, &end,
                                            EXTENT_DIRTY);
                if (ret)
                        break;
-               clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
                while(start <= end) {
+                       if (btrfs_congested_async(root->fs_info, 0))
+                               congestion_wait(WRITE, HZ/10);
+                       cond_resched();
+
                        index = start >> PAGE_CACHE_SHIFT;
                        start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
                        page = find_lock_page(btree_inode->i_mapping, index);
@@ -343,7 +346,30 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
                        page_cache_release(page);
                }
        }
-       err = filemap_fdatawait(btree_inode->i_mapping);
+       while(1) {
+               ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
+                                           EXTENT_DIRTY);
+               if (ret)
+                       break;
+
+               clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
+               while(start <= end) {
+                       index = start >> PAGE_CACHE_SHIFT;
+                       start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
+                       page = find_get_page(btree_inode->i_mapping, index);
+                       if (!page)
+                               continue;
+                       if (PageDirty(page)) {
+                               lock_page(page);
+                               err = write_one_page(page, 0);
+                               if (err)
+                                       werr = err;
+                       }
+                       wait_on_page_writeback(page);
+                       page_cache_release(page);
+                       cond_resched();
+               }
+       }
        if (err)
                werr = err;
        return werr;