@@ -1974,6 +1974,71 @@ static void cleanup_dirty_folios(struct btrfs_inode *inode,
mapping_set_error(mapping, error);
}
+static int nocow_one_range(struct btrfs_inode *inode,
+ struct folio *locked_folio,
+ struct extent_state **cached,
+ struct can_nocow_file_extent_args *nocow_args,
+ u64 file_pos, bool is_prealloc)
+{
+ struct btrfs_ordered_extent *ordered;
+ u64 len = nocow_args->file_extent.num_bytes;
+ u64 end = file_pos + len - 1;
+ int ret = 0;
+
+ lock_extent(&inode->io_tree, file_pos, end, cached);
+
+ if (is_prealloc) {
+ struct extent_map *em;
+
+ em = btrfs_create_io_em(inode, file_pos,
+ &nocow_args->file_extent,
+ BTRFS_ORDERED_PREALLOC);
+ if (IS_ERR(em)) {
+ unlock_extent(&inode->io_tree, file_pos,
+ end, cached);
+ return PTR_ERR(em);
+ }
+ free_extent_map(em);
+ }
+
+ ordered = btrfs_alloc_ordered_extent(inode, file_pos,
+ &nocow_args->file_extent,
+ is_prealloc
+ ? (1 << BTRFS_ORDERED_PREALLOC)
+ : (1 << BTRFS_ORDERED_NOCOW));
+ if (IS_ERR(ordered)) {
+ if (is_prealloc) {
+ btrfs_drop_extent_map_range(inode, file_pos,
+ end, false);
+ }
+ unlock_extent(&inode->io_tree, file_pos,
+ end, cached);
+ return PTR_ERR(ordered);
+ }
+
+ if (btrfs_is_data_reloc_root(inode->root))
+ /*
+ * Error handled later, as we must prevent
+ * extent_clear_unlock_delalloc() in error handler
+ * from freeing metadata of created ordered extent.
+ */
+ ret = btrfs_reloc_clone_csums(ordered);
+ btrfs_put_ordered_extent(ordered);
+
+ extent_clear_unlock_delalloc(inode, file_pos, end,
+ locked_folio, cached,
+ EXTENT_LOCKED | EXTENT_DELALLOC |
+ EXTENT_CLEAR_DATA_RESV,
+ PAGE_UNLOCK | PAGE_SET_ORDERED);
+
+ /*
+ * btrfs_reloc_clone_csums() error, now we're OK to call error
+ * handler, as metadata for created ordered extent will only
+ * be freed by btrfs_finish_ordered_io().
+ */
+ return ret;
+}
+
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
@@ -2018,15 +2083,12 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
while (cur_offset <= end) {
struct btrfs_block_group *nocow_bg = NULL;
- struct btrfs_ordered_extent *ordered;
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
struct extent_state *cached_state = NULL;
u64 extent_end;
- u64 nocow_end;
int extent_type;
- bool is_prealloc;
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
@@ -2160,67 +2222,13 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
}
}
- nocow_end = cur_offset + nocow_args.file_extent.num_bytes - 1;
- lock_extent(&inode->io_tree, cur_offset, nocow_end, &cached_state);
-
- is_prealloc = extent_type == BTRFS_FILE_EXTENT_PREALLOC;
- if (is_prealloc) {
- struct extent_map *em;
-
- em = btrfs_create_io_em(inode, cur_offset,
- &nocow_args.file_extent,
- BTRFS_ORDERED_PREALLOC);
- if (IS_ERR(em)) {
- unlock_extent(&inode->io_tree, cur_offset,
- nocow_end, &cached_state);
- btrfs_dec_nocow_writers(nocow_bg);
- ret = PTR_ERR(em);
- goto error;
- }
- free_extent_map(em);
- }
-
- ordered = btrfs_alloc_ordered_extent(inode, cur_offset,
- &nocow_args.file_extent,
- is_prealloc
- ? (1 << BTRFS_ORDERED_PREALLOC)
- : (1 << BTRFS_ORDERED_NOCOW));
+ ret = nocow_one_range(inode, locked_folio, &cached_state,
+ &nocow_args, cur_offset,
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC);
btrfs_dec_nocow_writers(nocow_bg);
- if (IS_ERR(ordered)) {
- if (is_prealloc) {
- btrfs_drop_extent_map_range(inode, cur_offset,
- nocow_end, false);
- }
- unlock_extent(&inode->io_tree, cur_offset,
- nocow_end, &cached_state);
- ret = PTR_ERR(ordered);
+ if (ret < 0)
goto error;
- }
-
- if (btrfs_is_data_reloc_root(root))
- /*
- * Error handled later, as we must prevent
- * extent_clear_unlock_delalloc() in error handler
- * from freeing metadata of created ordered extent.
- */
- ret = btrfs_reloc_clone_csums(ordered);
- btrfs_put_ordered_extent(ordered);
-
- extent_clear_unlock_delalloc(inode, cur_offset, nocow_end,
- locked_folio, &cached_state,
- EXTENT_LOCKED | EXTENT_DELALLOC |
- EXTENT_CLEAR_DATA_RESV,
- PAGE_UNLOCK | PAGE_SET_ORDERED);
-
cur_offset = extent_end;
-
- /*
- * btrfs_reloc_clone_csums() error, now we're OK to call error
- * handler, as metadata for created ordered extent will only
- * be freed by btrfs_finish_ordered_io().
- */
- if (ret)
- goto error;
}
btrfs_release_path(path);
Currently we're doing all the ordered extent and extent map generation inside a while() loop of run_delalloc_nocow(). This makes it pretty hard to read, nor do proper error handling. So move that part of code into a helper, nocow_one_range(). This should not change anything, but there is a tiny timing change where btrfs_dec_nocow_writers() is only called after nocow_one_range() helper exits. This timing change is small, and makes error handling easier, thus should be fine. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/inode.c | 130 +++++++++++++++++++++++++---------------------- 1 file changed, 69 insertions(+), 61 deletions(-)