*/
struct list_head delalloc_inodes;
+ /*
+ * list for tracking inodes that must be sent to disk before a
+ * rename or truncate commit
+ */
+ struct list_head ordered_operations;
+
/* the space_info for where this inode's data allocations are done */
struct btrfs_space_info *space_info;
*/
u64 last_unlink_trans;
+ /*
+ * ordered_data_close is set by truncate when a file that used
+ * to have good data has been truncated to zero. When it is set
+ * the btrfs file release call will add this inode to the
+ * ordered operations list so that we make sure to flush out any
+ * new data the application may have written before commit.
+ *
+ * yes, its silly to have a single bitflag, but we might grow more
+ * of these.
+ */
+ unsigned ordered_data_close:1;
+
struct inode vfs_inode;
};
#define BTRFS_MAX_LEVEL 8
+/*
+ * files bigger than this get some pre-flushing when they are added
+ * to the ordered operations list. That way we limit the total
+ * work done by the commit
+ */
+#define BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT (8 * 1024 * 1024)
+
/* holds pointers to all of the tree roots */
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
struct mutex volume_mutex;
struct mutex tree_reloc_mutex;
+ /*
+ * this protects the ordered operations list only while we are
+ * processing all of the entries on it. This way we make
+ * sure the commit code doesn't find the list temporarily empty
+ * because another function happens to be doing non-waiting preflush
+ * before jumping into the main commit.
+ */
+ struct mutex ordered_operations_mutex;
+
struct list_head trans_list;
struct list_head hashers;
struct list_head dead_roots;
* ordered extents
*/
spinlock_t ordered_extent_lock;
+
+ /*
+ * all of the data=ordered extents pending writeback
+ * these can span multiple transactions and basically include
+ * every dirty data page that isn't from nodatacow
+ */
struct list_head ordered_extents;
+
+ /*
+ * all of the inodes that have delalloc bytes. It is possible for
+ * this list to be empty even when there is still dirty data=ordered
+ * extents waiting to finish IO.
+ */
struct list_head delalloc_inodes;
/*
+ * special rename and truncate targets that must be on disk before
+ * we're allowed to commit. This is basically the ext3 style
+ * data=ordered list.
+ */
+ struct list_head ordered_operations;
+
+ /*
* there is a pool of worker threads for checksumming during writes
* and a pool for checksumming after reads. This is because readers
* can run with FS locks held, and the writers may be waiting for
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->hashers);
INIT_LIST_HEAD(&fs_info->delalloc_inodes);
+ INIT_LIST_HEAD(&fs_info->ordered_operations);
spin_lock_init(&fs_info->delalloc_lock);
spin_lock_init(&fs_info->new_trans_lock);
spin_lock_init(&fs_info->ref_cache_lock);
insert_inode_hash(fs_info->btree_inode);
mutex_init(&fs_info->trans_mutex);
+ mutex_init(&fs_info->ordered_operations_mutex);
mutex_init(&fs_info->tree_log_mutex);
mutex_init(&fs_info->drop_mutex);
mutex_init(&fs_info->pinned_mutex);
page_cache_release(pinned[1]);
*ppos = pos;
+ /*
+ * we want to make sure fsync finds this change
+ * but we haven't joined a transaction running right now.
+ *
+ * Later on, someone is sure to update the inode and get the
+ * real transid recorded.
+ *
+ * We set last_trans now to the fs_info generation + 1,
+ * this will either be one more than the running transaction
+ * or the generation used for the next transaction if there isn't
+ * one running right now.
+ */
+ BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
+
if (num_written > 0 && will_write) {
struct btrfs_trans_handle *trans;
int btrfs_release_file(struct inode *inode, struct file *filp)
{
+ /*
+ * ordered_data_close is set by settattr when we are about to truncate
+ * a file from a non-zero size to a zero size. This tries to
+ * flush down new bytes that may have been written if the
+ * application were using truncate to replace a file in place.
+ */
+ if (BTRFS_I(inode)->ordered_data_close) {
+ BTRFS_I(inode)->ordered_data_close = 0;
+ btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
+ if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+ filemap_flush(inode->i_mapping);
+ }
if (filp->private_data)
btrfs_ioctl_trans_end(filp);
return 0;
if (err)
return err;
- if (S_ISREG(inode->i_mode) &&
- attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
- err = btrfs_cont_expand(inode, attr->ia_size);
- if (err)
- return err;
+ if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
+ if (attr->ia_size > inode->i_size) {
+ err = btrfs_cont_expand(inode, attr->ia_size);
+ if (err)
+ return err;
+ } else if (inode->i_size > 0 &&
+ attr->ia_size == 0) {
+
+ /* we're truncating a file that used to have good
+ * data down to zero. Make sure it gets into
+ * the ordered flush list so that any new writes
+ * get down to disk quickly.
+ */
+ BTRFS_I(inode)->ordered_data_close = 1;
+ }
}
err = inode_setattr(inode, attr);
extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
inode->i_mapping, GFP_NOFS);
INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
+ INIT_LIST_HEAD(&BTRFS_I(inode)->ordered_operations);
btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
mutex_init(&BTRFS_I(inode)->extent_mutex);
mutex_init(&BTRFS_I(inode)->log_mutex);
}
ClearPageChecked(page);
set_page_dirty(page);
+
+ BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
out_unlock:
btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
trans = btrfs_start_transaction(root, 1);
+
+ /*
+ * setattr is responsible for setting the ordered_data_close flag,
+ * but that is only tested during the last file release. That
+ * could happen well after the next commit, leaving a great big
+ * window where new writes may get lost if someone chooses to write
+ * to this file after truncating to zero
+ *
+ * The inode doesn't have any dirty data here, and so if we commit
+ * this is a noop. If someone immediately starts writing to the inode
+ * it is very likely we'll catch some of their writes in this
+ * transaction, and the commit will find this file on the ordered
+ * data list with good things to send down.
+ *
+ * This is a best effort solution, there is still a window where
+ * using truncate to replace the contents of the file will
+ * end up with a zero length file after a crash.
+ */
+ if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
+ btrfs_add_ordered_operation(trans, root, inode);
+
btrfs_set_trans_block_group(trans, inode);
btrfs_i_size_write(inode, inode->i_size);
ei->i_acl = BTRFS_ACL_NOT_CACHED;
ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
INIT_LIST_HEAD(&ei->i_orphan);
+ INIT_LIST_HEAD(&ei->ordered_operations);
return &ei->vfs_inode;
}
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_ordered_extent *ordered;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
WARN_ON(!list_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
posix_acl_release(BTRFS_I(inode)->i_default_acl);
- spin_lock(&BTRFS_I(inode)->root->list_lock);
+ /*
+ * Make sure we're properly removed from the ordered operation
+ * lists.
+ */
+ smp_mb();
+ if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
+ spin_lock(&root->fs_info->ordered_extent_lock);
+ list_del_init(&BTRFS_I(inode)->ordered_operations);
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+ }
+
+ spin_lock(&root->list_lock);
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
" list\n", inode->i_ino);
dump_stack();
}
- spin_unlock(&BTRFS_I(inode)->root->list_lock);
+ spin_unlock(&root->list_lock);
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (ret)
goto out_unlock;
+ /*
+ * we're using rename to replace one file with another.
+ * and the replacement file is large. Start IO on it now so
+ * we don't add too much work to the end of the transaction
+ */
+ if (new_inode && old_inode && S_ISREG(old_inode->i_mode) &&
+ new_inode->i_size &&
+ old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+ filemap_flush(old_inode->i_mapping);
+
trans = btrfs_start_transaction(root, 1);
/*
+ * make sure the inode gets flushed if it is replacing
+ * something.
+ */
+ if (new_inode && new_inode->i_size &&
+ old_inode && S_ISREG(old_inode->i_mode)) {
+ btrfs_add_ordered_operation(trans, root, old_inode);
+ }
+
+ /*
* this is an ugly little race, but the rename is required to make
* sure that if we crash, the inode is either at the old name
* or the new one. pinning the log transaction lets us make sure
spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
list_del_init(&entry->root_extent_list);
+
+ /*
+ * we have no more ordered extents for this inode and
+ * no dirty pages. We can safely remove it from the
+ * list of ordered extents
+ */
+ if (RB_EMPTY_ROOT(&tree->tree) &&
+ !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
+ list_del_init(&BTRFS_I(inode)->ordered_operations);
+ }
spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
mutex_unlock(&tree->mutex);
}
/*
+ * this is used during transaction commit to write all the inodes
+ * added to the ordered operation list. These files must be fully on
+ * disk before the transaction commits.
+ *
+ * we have two modes here, one is to just start the IO via filemap_flush
+ * and the other is to wait for all the io. When we wait, we have an
+ * extra check to make sure the ordered operation list really is empty
+ * before we return
+ */
+int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
+{
+ struct btrfs_inode *btrfs_inode;
+ struct inode *inode;
+ struct list_head splice;
+
+ INIT_LIST_HEAD(&splice);
+
+ mutex_lock(&root->fs_info->ordered_operations_mutex);
+ spin_lock(&root->fs_info->ordered_extent_lock);
+again:
+ list_splice_init(&root->fs_info->ordered_operations, &splice);
+
+ while (!list_empty(&splice)) {
+ btrfs_inode = list_entry(splice.next, struct btrfs_inode,
+ ordered_operations);
+
+ inode = &btrfs_inode->vfs_inode;
+
+ list_del_init(&btrfs_inode->ordered_operations);
+
+ /*
+ * the inode may be getting freed (in sys_unlink path).
+ */
+ inode = igrab(inode);
+
+ if (!wait && inode) {
+ list_add_tail(&BTRFS_I(inode)->ordered_operations,
+ &root->fs_info->ordered_operations);
+ }
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+
+ if (inode) {
+ if (wait)
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ else
+ filemap_flush(inode->i_mapping);
+ iput(inode);
+ }
+
+ cond_resched();
+ spin_lock(&root->fs_info->ordered_extent_lock);
+ }
+ if (wait && !list_empty(&root->fs_info->ordered_operations))
+ goto again;
+
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+ mutex_unlock(&root->fs_info->ordered_operations_mutex);
+
+ return 0;
+}
+
+/*
* Used to start IO or wait for a given ordered extent to finish.
*
* If wait is one, this effectively waits on page writeback for all the pages
return ret;
}
+
+/*
+ * add a given inode to the list of inodes that must be fully on
+ * disk before a transaction commit finishes.
+ *
+ * This basically gives us the ext3 style data=ordered mode, and it is mostly
+ * used to make sure renamed files are fully on disk.
+ *
+ * It is a noop if the inode is already fully on disk.
+ *
+ * If trans is not null, we'll do a friendly check for a transaction that
+ * is already flushing things and force the IO down ourselves.
+ */
+int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ u64 last_mod;
+
+ last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
+
+ /*
+ * if this file hasn't been changed since the last transaction
+ * commit, we can safely return without doing anything
+ */
+ if (last_mod < root->fs_info->last_trans_committed)
+ return 0;
+
+ /*
+ * the transaction is already committing. Just start the IO and
+ * don't bother with all of this list nonsense
+ */
+ if (trans && root->fs_info->running_transaction->blocked) {
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ return 0;
+ }
+
+ spin_lock(&root->fs_info->ordered_extent_lock);
+ if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
+ list_add_tail(&BTRFS_I(inode)->ordered_operations,
+ &root->fs_info->ordered_operations);
+ }
+ spin_unlock(&root->fs_info->ordered_extent_lock);
+
+ return 0;
+}
int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
loff_t end, int sync_mode);
int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
+int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
+int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode);
#endif
int should_grow = 0;
unsigned long now = get_seconds();
+ btrfs_run_ordered_operations(root, 0);
+
/* make a pass through all the delayed refs we have so far
* any runnings procs may add more while we are here
*/
BUG_ON(ret);
}
+ /*
+ * rename don't use btrfs_join_transaction, so, once we
+ * set the transaction to blocked above, we aren't going
+ * to get any new ordered operations. We can safely run
+ * it here and no for sure that nothing new will be added
+ * to the list
+ */
+ btrfs_run_ordered_operations(root, 1);
+
smp_mb();
if (cur_trans->num_writers > 1 || should_grow)
schedule_timeout(timeout);
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff