/* get the inode */
key.objectid = defrag->root;
- btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
index = srcu_read_lock(&fs_info->subvol_srcu);
}
key.objectid = defrag->ino;
- btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
if (IS_ERR(inode)) {
if (unlikely(copied == 0))
break;
- if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
+ if (copied < PAGE_CACHE_SIZE - offset) {
offset += copied;
} else {
pg++;
bool force_page_uptodate = false;
bool need_unlock;
- nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
- PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
- (sizeof(struct page *)));
+ nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_CACHE_SIZE),
+ PAGE_CACHE_SIZE / (sizeof(struct page *)));
nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
nrptrs = max(nrptrs, 8);
pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
size_t write_bytes = min(iov_iter_count(i),
nrptrs * (size_t)PAGE_CACHE_SIZE -
offset);
- size_t num_pages = (write_bytes + offset +
- PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
+ PAGE_CACHE_SIZE);
size_t reserve_bytes;
size_t dirty_pages;
size_t copied;
* our prealloc extent may be smaller than
* write_bytes, so scale down.
*/
- num_pages = (write_bytes + offset +
- PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
+ num_pages = DIV_ROUND_UP(write_bytes + offset,
+ PAGE_CACHE_SIZE);
reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
ret = 0;
} else {
dirty_pages = 0;
} else {
force_page_uptodate = false;
- dirty_pages = (copied + offset +
- PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
+ dirty_pages = DIV_ROUND_UP(copied + offset,
+ PAGE_CACHE_SIZE);
}
/*
cond_resched();
balance_dirty_pages_ratelimited(inode->i_mapping);
- if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+ if (dirty_pages < (root->nodesize >> PAGE_CACHE_SHIFT) + 1)
btrfs_btree_balance_dirty(root);
pos += copied;
if (sync)
atomic_inc(&BTRFS_I(inode)->sync_writers);
- if (unlikely(file->f_flags & O_DIRECT)) {
+ if (file->f_flags & O_DIRECT) {
num_written = __btrfs_direct_write(iocb, from, pos);
} else {
num_written = __btrfs_buffered_write(file, from, pos);
return 0;
}
+static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
+{
+ int ret;
+
+ atomic_inc(&BTRFS_I(inode)->sync_writers);
+ ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
+ if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+ &BTRFS_I(inode)->runtime_flags))
+ ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
+ atomic_dec(&BTRFS_I(inode)->sync_writers);
+
+ return ret;
+}
+
/*
* fsync call for both files and directories. This logs the inode into
* the tree log instead of forcing full commits whenever possible.
* multi-task, and make the performance up. See
* btrfs_wait_ordered_range for an explanation of the ASYNC check.
*/
- atomic_inc(&BTRFS_I(inode)->sync_writers);
- ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
- if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
- &BTRFS_I(inode)->runtime_flags))
- ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
- atomic_dec(&BTRFS_I(inode)->sync_writers);
+ ret = start_ordered_ops(inode, start, end);
if (ret)
return ret;
mutex_lock(&inode->i_mutex);
-
- /*
- * We flush the dirty pages again to avoid some dirty pages in the
- * range being left.
- */
atomic_inc(&root->log_batch);
full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
+ /*
+ * We might have have had more pages made dirty after calling
+ * start_ordered_ops and before acquiring the inode's i_mutex.
+ */
if (full_sync) {
+ /*
+ * For a full sync, we need to make sure any ordered operations
+ * start and finish before we start logging the inode, so that
+ * all extents are persisted and the respective file extent
+ * items are in the fs/subvol btree.
+ */
ret = btrfs_wait_ordered_range(inode, start, end - start + 1);
- if (ret) {
- mutex_unlock(&inode->i_mutex);
- goto out;
- }
+ } else {
+ /*
+ * Start any new ordered operations before starting to log the
+ * inode. We will wait for them to finish in btrfs_sync_log().
+ *
+ * Right before acquiring the inode's mutex, we might have new
+ * writes dirtying pages, which won't immediately start the
+ * respective ordered operations - that is done through the
+ * fill_delalloc callbacks invoked from the writepage and
+ * writepages address space operations. So make sure we start
+ * all ordered operations before starting to log our inode. Not
+ * doing this means that while logging the inode, writeback
+ * could start and invoke writepage/writepages, which would call
+ * the fill_delalloc callbacks (cow_file_range,
+ * submit_compressed_extents). These callbacks add first an
+ * extent map to the modified list of extents and then create
+ * the respective ordered operation, which means in
+ * tree-log.c:btrfs_log_inode() we might capture all existing
+ * ordered operations (with btrfs_get_logged_extents()) before
+ * the fill_delalloc callback adds its ordered operation, and by
+ * the time we visit the modified list of extent maps (with
+ * btrfs_log_changed_extents()), we see and process the extent
+ * map they created. We then use the extent map to construct a
+ * file extent item for logging without waiting for the
+ * respective ordered operation to finish - this file extent
+ * item points to a disk location that might not have yet been
+ * written to, containing random data - so after a crash a log
+ * replay will make our inode have file extent items that point
+ * to disk locations containing invalid data, as we returned
+ * success to userspace without waiting for the respective
+ * ordered operation to finish, because it wasn't captured by
+ * btrfs_get_logged_extents().
+ */
+ ret = start_ordered_ops(inode, start, end);
+ }
+ if (ret) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
}
atomic_inc(&root->log_batch);
*/
mutex_unlock(&inode->i_mutex);
+ /*
+ * If any of the ordered extents had an error, just return it to user
+ * space, so that the application knows some writes didn't succeed and
+ * can take proper action (retry for e.g.). Blindly committing the
+ * transaction in this case, would fool userspace that everything was
+ * successful. And we also want to make sure our log doesn't contain
+ * file extent items pointing to extents that weren't fully written to -
+ * just like in the non fast fsync path, where we check for the ordered
+ * operation's error flag before writing to the log tree and return -EIO
+ * if any of them had this flag set (btrfs_wait_ordered_range) -
+ * therefore we need to check for errors in the ordered operations,
+ * which are indicated by ctx.io_err.
+ */
+ if (ctx.io_err) {
+ btrfs_end_transaction(trans, root);
+ ret = ctx.io_err;
+ goto out;
+ }
+
if (ret != BTRFS_NO_LOG_SYNC) {
if (!ret) {
ret = btrfs_sync_log(trans, root, &ctx);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
- u64 lockstart = *offset;
- u64 lockend = i_size_read(inode);
- u64 start = *offset;
- u64 len = i_size_read(inode);
+ u64 lockstart;
+ u64 lockend;
+ u64 start;
+ u64 len;
int ret = 0;
- lockend = max_t(u64, root->sectorsize, lockend);
+ if (inode->i_size == 0)
+ return -ENXIO;
+
+ /*
+ * *offset can be negative, in this case we start finding DATA/HOLE from
+ * the very start of the file.
+ */
+ start = max_t(loff_t, 0, *offset);
+
+ lockstart = round_down(start, root->sectorsize);
+ lockend = round_up(i_size_read(inode), root->sectorsize);
if (lockend <= lockstart)
lockend = lockstart + root->sectorsize;
-
lockend--;
len = lockend - lockstart + 1;
- len = max_t(u64, len, root->sectorsize);
- if (inode->i_size == 0)
- return -ENXIO;
-
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
&cached_state);
projects / cascardo / linux.git / blobdiff