btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ buf->log_index = root->log_transid % 2;
/*
* we allow two log transactions at a time, use different
* EXENT bit to differentiate dirty pages.
*/
- if (root->log_transid % 2 == 0)
+ if (buf->log_index == 0)
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
else
set_extent_new(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
} else {
+ buf->log_index = -1;
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
}
wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
}
+static void set_btree_ioerr(struct page *page)
+{
+ struct extent_buffer *eb = (struct extent_buffer *)page->private;
+ struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode);
+
+ SetPageError(page);
+ if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
+ return;
+
+ /*
+ * If writeback for a btree extent that doesn't belong to a log tree
+ * failed, increment the counter transaction->eb_write_errors.
+ * We do this because while the transaction is running and before it's
+ * committing (when we call filemap_fdata[write|wait]_range against
+ * the btree inode), we might have
+ * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
+ * returns an error or an error happens during writeback, when we're
+ * committing the transaction we wouldn't know about it, since the pages
+ * can be no longer dirty nor marked anymore for writeback (if a
+ * subsequent modification to the extent buffer didn't happen before the
+ * transaction commit), which makes filemap_fdata[write|wait]_range not
+ * able to find the pages tagged with SetPageError at transaction
+ * commit time. So if this happens we must abort the transaction,
+ * otherwise we commit a super block with btree roots that point to
+ * btree nodes/leafs whose content on disk is invalid - either garbage
+ * or the content of some node/leaf from a past generation that got
+ * cowed or deleted and is no longer valid.
+ *
+ * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
+ * not be enough - we need to distinguish between log tree extents vs
+ * non-log tree extents, and the next filemap_fdatawait_range() call
+ * will catch and clear such errors in the mapping - and that call might
+ * be from a log sync and not from a transaction commit. Also, checking
+ * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
+ * not done and would not be reliable - the eb might have been released
+ * from memory and reading it back again means that flag would not be
+ * set (since it's a runtime flag, not persisted on disk).
+ *
+ * Using the flags below in the btree inode also makes us achieve the
+ * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
+ * writeback for all dirty pages and before filemap_fdatawait_range()
+ * is called, the writeback for all dirty pages had already finished
+ * with errors - because we were not using AS_EIO/AS_ENOSPC,
+ * filemap_fdatawait_range() would return success, as it could not know
+ * that writeback errors happened (the pages were no longer tagged for
+ * writeback).
+ */
+ switch (eb->log_index) {
+ case -1:
+ set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags);
+ break;
+ case 0:
+ set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
+ break;
+ case 1:
+ set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
+ break;
+ default:
+ BUG(); /* unexpected, logic error */
+ }
+}
+
static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
{
struct bio_vec *bvec;
BUG_ON(!eb);
done = atomic_dec_and_test(&eb->io_pages);
- if (err || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
- set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+ if (err || test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
ClearPageUptodate(page);
- SetPageError(page);
+ set_btree_ioerr(page);
}
end_page_writeback(page);
int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
int ret = 0;
- clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+ clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
num_pages = num_extent_pages(eb->start, eb->len);
atomic_set(&eb->io_pages, num_pages);
if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID)
0, epd->bio_flags, bio_flags);
epd->bio_flags = bio_flags;
if (ret) {
- set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
- SetPageError(p);
+ set_btree_ioerr(p);
end_page_writeback(p);
if (atomic_sub_and_test(num_pages - i, &eb->io_pages))
end_extent_buffer_writeback(eb);
goto unlock_exit;
}
- clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
+ clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
eb->read_mirror = 0;
atomic_set(&eb->io_pages, num_reads);
for (i = start_i; i < num_pages; i++) {
struct extent_state *cached_state = NULL;
u64 start = 0;
u64 end;
+ struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
+ bool errors = false;
while (!find_first_extent_bit(dirty_pages, start, &start, &end,
EXTENT_NEED_WAIT, &cached_state)) {
}
if (err)
werr = err;
+
+ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ if ((mark & EXTENT_DIRTY) &&
+ test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR,
+ &btree_ino->runtime_flags))
+ errors = true;
+
+ if ((mark & EXTENT_NEW) &&
+ test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR,
+ &btree_ino->runtime_flags))
+ errors = true;
+ } else {
+ if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR,
+ &btree_ino->runtime_flags))
+ errors = true;
+ }
+
+ if (errors && !werr)
+ werr = -EIO;
+
return werr;
}
{
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_transaction *prev_trans = NULL;
+ struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode);
int ret;
/* Stop the commit early if ->aborted is set */
btrfs_update_commit_device_size(root->fs_info);
btrfs_update_commit_device_bytes_used(root, cur_trans);
+ clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags);
+ clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags);
+
spin_lock(&root->fs_info->trans_lock);
cur_trans->state = TRANS_STATE_UNBLOCKED;
root->fs_info->running_transaction = NULL;