Btrfs: Update on disk i_size only after pending ordered extents are done

This changes the ordered data code to update i_size after the extent
is on disk.  An on disk i_size is maintained in the in-memory btrfs inode
structures, and this is updated as extents finish.

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

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 8d03687..81c0444 100644 (file)
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -40,11 +40,20 @@ struct btrfs_inode {
         */
        u64 last_trans;
        u64 delalloc_bytes;
+       u64 disk_i_size;
        u32 flags;
 };
+
 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 {
        return container_of(inode, struct btrfs_inode, vfs_inode);
 }
 
+static inline void btrfs_i_size_write(struct inode *inode, u64 size)
+{
+       inode->i_size = size;
+       BTRFS_I(inode)->disk_i_size = size;
+}
+
+
 #endif

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2092863..3e4e5c2 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -338,7 +338,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
                btrfs_update_inode(trans, root, inode);
        }
 failed:
-       err = btrfs_end_transaction(trans, root);
+       err = btrfs_end_transaction_throttle(trans, root);
 out_unlock:
        unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
        return err;

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 47a008c..baf4601 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -542,6 +542,7 @@ int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
        add_pending_csums(trans, inode, ordered_extent->file_offset,
                          &ordered_extent->list);
 
+       btrfs_ordered_update_i_size(inode, ordered_extent);
        btrfs_remove_ordered_extent(inode, ordered_extent);
        /* once for us */
        btrfs_put_ordered_extent(ordered_extent);
@@ -792,7 +793,7 @@ void btrfs_read_locked_inode(struct inode *inode)
        inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
        inode->i_uid = btrfs_inode_uid(leaf, inode_item);
        inode->i_gid = btrfs_inode_gid(leaf, inode_item);
-       inode->i_size = btrfs_inode_size(leaf, inode_item);
+       btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
 
        tspec = btrfs_inode_atime(inode_item);
        inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
@@ -860,7 +861,7 @@ static void fill_inode_item(struct extent_buffer *leaf,
 {
        btrfs_set_inode_uid(leaf, item, inode->i_uid);
        btrfs_set_inode_gid(leaf, item, inode->i_gid);
-       btrfs_set_inode_size(leaf, item, inode->i_size);
+       btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
        btrfs_set_inode_mode(leaf, item, inode->i_mode);
        btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
 
@@ -982,7 +983,7 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
 err:
        btrfs_free_path(path);
        if (!ret) {
-               dir->i_size -= name_len * 2;
+               btrfs_i_size_write(dir, dir->i_size - name_len * 2);
                dir->i_mtime = dir->i_ctime = CURRENT_TIME;
                btrfs_update_inode(trans, root, dir);
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
@@ -1044,7 +1045,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
        /* now the directory is empty */
        err = btrfs_unlink_trans(trans, root, dir, dentry);
        if (!err) {
-               inode->i_size = 0;
+               btrfs_i_size_write(inode, 0);
        }
 
        nr = trans->blocks_used;
@@ -1089,7 +1090,6 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
        int extent_type = -1;
        u64 mask = root->sectorsize - 1;
 
-       btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
        btrfs_drop_extent_cache(inode, inode->i_size & (~mask), (u64)-1);
        path = btrfs_alloc_path();
        path->reada = -1;
@@ -1427,7 +1427,7 @@ void btrfs_delete_inode(struct inode *inode)
                goto no_delete;
        }
 
-       inode->i_size = 0;
+       btrfs_i_size_write(inode, 0);
        trans = btrfs_start_transaction(root, 1);
 
        btrfs_set_trans_block_group(trans, inode);
@@ -1561,6 +1561,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
        inode->i_ino = args->ino;
        BTRFS_I(inode)->root = args->root;
        BTRFS_I(inode)->delalloc_bytes = 0;
+       BTRFS_I(inode)->disk_i_size = 0;
        extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
        extent_io_tree_init(&BTRFS_I(inode)->io_tree,
                             inode->i_mapping, GFP_NOFS);
@@ -1869,6 +1870,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
                             inode->i_mapping, GFP_NOFS);
        mutex_init(&BTRFS_I(inode)->csum_mutex);
        BTRFS_I(inode)->delalloc_bytes = 0;
+       BTRFS_I(inode)->disk_i_size = 0;
        BTRFS_I(inode)->root = root;
 
        if (mode & S_IFDIR)
@@ -1964,7 +1966,8 @@ static int btrfs_add_link(struct btrfs_trans_handle *trans,
                                             dentry->d_parent->d_inode->i_ino);
                }
                parent_inode = dentry->d_parent->d_inode;
-               parent_inode->i_size += dentry->d_name.len * 2;
+               btrfs_i_size_write(parent_inode, parent_inode->i_size +
+                                  dentry->d_name.len * 2);
                parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
                ret = btrfs_update_inode(trans, root,
                                         dentry->d_parent->d_inode);
@@ -2092,6 +2095,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
                                     inode->i_mapping, GFP_NOFS);
                mutex_init(&BTRFS_I(inode)->csum_mutex);
                BTRFS_I(inode)->delalloc_bytes = 0;
+               BTRFS_I(inode)->disk_i_size = 0;
                BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
        }
        dir->i_sb->s_dirt = 1;
@@ -2199,7 +2203,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        inode->i_fop = &btrfs_dir_file_operations;
        btrfs_set_trans_block_group(trans, inode);
 
-       inode->i_size = 0;
+       btrfs_i_size_write(inode, 0);
        err = btrfs_update_inode(trans, root, inode);
        if (err)
                goto out_fail;
@@ -2756,6 +2760,7 @@ static void btrfs_truncate(struct inode *inode)
        int ret;
        struct btrfs_trans_handle *trans;
        unsigned long nr;
+       u64 mask = root->sectorsize - 1;
 
        if (!S_ISREG(inode->i_mode))
                return;
@@ -2766,6 +2771,8 @@ static void btrfs_truncate(struct inode *inode)
 
        trans = btrfs_start_transaction(root, 1);
        btrfs_set_trans_block_group(trans, inode);
+       btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
+       btrfs_i_size_write(inode, inode->i_size);
 
        /* FIXME, add redo link to tree so we don't leak on crash */
        ret = btrfs_truncate_in_trans(trans, root, inode,
@@ -2821,7 +2828,7 @@ int btrfs_create_subvol_root(struct btrfs_root *new_root,
        ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
                                     new_dirid);
        inode->i_nlink = 1;
-       inode->i_size = 0;
+       btrfs_i_size_write(inode, 0);
 
        return btrfs_update_inode(trans, new_root, inode);
 }
@@ -3069,6 +3076,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
                                     inode->i_mapping, GFP_NOFS);
                mutex_init(&BTRFS_I(inode)->csum_mutex);
                BTRFS_I(inode)->delalloc_bytes = 0;
+               BTRFS_I(inode)->disk_i_size = 0;
                BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
        }
        dir->i_sb->s_dirt = 1;
@@ -3103,7 +3111,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
        inode->i_op = &btrfs_symlink_inode_operations;
        inode->i_mapping->a_ops = &btrfs_symlink_aops;
        inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
-       inode->i_size = name_len - 1;
+       btrfs_i_size_write(inode, name_len - 1);
        err = btrfs_update_inode(trans, root, inode);
        if (err)
                drop_inode = 1;

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 6513270..d86a953 100644 (file)
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -406,3 +406,92 @@ out:
        mutex_unlock(&tree->mutex);
        return entry;
 }
+
+int btrfs_ordered_update_i_size(struct inode *inode,
+                               struct btrfs_ordered_extent *ordered)
+{
+       struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+       struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+       u64 disk_i_size;
+       u64 new_i_size;
+       u64 i_size_test;
+       struct rb_node *node;
+       struct btrfs_ordered_extent *test;
+
+       mutex_lock(&tree->mutex);
+       disk_i_size = BTRFS_I(inode)->disk_i_size;
+
+       /*
+        * if the disk i_size is already at the inode->i_size, or
+        * this ordered extent is inside the disk i_size, we're done
+        */
+       if (disk_i_size >= inode->i_size ||
+           ordered->file_offset + ordered->len <= disk_i_size) {
+               goto out;
+       }
+
+       /*
+        * we can't update the disk_isize if there are delalloc bytes
+        * between disk_i_size and  this ordered extent
+        */
+       if (test_range_bit(io_tree, disk_i_size,
+                          ordered->file_offset + ordered->len - 1,
+                          EXTENT_DELALLOC, 0)) {
+               goto out;
+       }
+       /*
+        * walk backward from this ordered extent to disk_i_size.
+        * if we find an ordered extent then we can't update disk i_size
+        * yet
+        */
+       while(1) {
+               node = rb_prev(&ordered->rb_node);
+               if (!node)
+                       break;
+               test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+               if (test->file_offset + test->len <= disk_i_size)
+                       break;
+               if (test->file_offset >= inode->i_size)
+                       break;
+               if (test->file_offset >= disk_i_size)
+                       goto out;
+       }
+       new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode));
+
+       /*
+        * at this point, we know we can safely update i_size to at least
+        * the offset from this ordered extent.  But, we need to
+        * walk forward and see if ios from higher up in the file have
+        * finished.
+        */
+       node = rb_next(&ordered->rb_node);
+       i_size_test = 0;
+       if (node) {
+               /*
+                * do we have an area where IO might have finished
+                * between our ordered extent and the next one.
+                */
+               test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+               if (test->file_offset > entry_end(ordered)) {
+                       i_size_test = test->file_offset - 1;
+               }
+       } else {
+               i_size_test = i_size_read(inode);
+       }
+
+       /*
+        * i_size_test is the end of a region after this ordered
+        * extent where there are no ordered extents.  As long as there
+        * are no delalloc bytes in this area, it is safe to update
+        * disk_i_size to the end of the region.
+        */
+       if (i_size_test > entry_end(ordered) &&
+           !test_range_bit(io_tree, entry_end(ordered), i_size_test,
+                          EXTENT_DELALLOC, 0)) {
+               new_i_size = min_t(u64, i_size_test, i_size_read(inode));
+       }
+       BTRFS_I(inode)->disk_i_size = new_i_size;
+out:
+       mutex_unlock(&tree->mutex);
+       return 0;
+}

diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 33292c5..40e9126 100644 (file)
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -89,4 +89,6 @@ btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 int btrfs_add_ordered_pending(struct inode *inode,
                              struct btrfs_ordered_extent *ordered,
                              u64 start, u64 len);
+int btrfs_ordered_update_i_size(struct inode *inode,
+                               struct btrfs_ordered_extent *ordered);
 #endif