1 files changed, 296 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
new file mode 100644
index 000000000..7929f054d
--- /dev/null
+++ b/fs/btrfs/extent_io.h
@@ -0,0 +1,296 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_EXTENT_IO_H
+#define BTRFS_EXTENT_IO_H
+
+#include <linux/rbtree.h>
+#include <linux/refcount.h>
+#include <linux/fiemap.h>
+#include <linux/btrfs_tree.h>
+#include "compression.h"
+#include "ulist.h"
+
+enum {
+	EXTENT_BUFFER_UPTODATE,
+	EXTENT_BUFFER_DIRTY,
+	EXTENT_BUFFER_CORRUPT,
+	/* this got triggered by readahead */
+	EXTENT_BUFFER_READAHEAD,
+	EXTENT_BUFFER_TREE_REF,
+	EXTENT_BUFFER_STALE,
+	EXTENT_BUFFER_WRITEBACK,
+	/* read IO error */
+	EXTENT_BUFFER_READ_ERR,
+	EXTENT_BUFFER_UNMAPPED,
+	EXTENT_BUFFER_IN_TREE,
+	/* write IO error */
+	EXTENT_BUFFER_WRITE_ERR,
+	EXTENT_BUFFER_NO_CHECK,
+};
+
+/* these are flags for __process_pages_contig */
+#define PAGE_UNLOCK		(1 << 0)
+/* Page starts writeback, clear dirty bit and set writeback bit */
+#define PAGE_START_WRITEBACK	(1 << 1)
+#define PAGE_END_WRITEBACK	(1 << 2)
+#define PAGE_SET_ORDERED	(1 << 3)
+#define PAGE_SET_ERROR		(1 << 4)
+#define PAGE_LOCK		(1 << 5)
+
+/*
+ * page->private values.  Every page that is controlled by the extent
+ * map has page->private set to one.
+ */
+#define EXTENT_PAGE_PRIVATE 1
+
+/*
+ * The extent buffer bitmap operations are done with byte granularity instead of
+ * word granularity for two reasons:
+ * 1. The bitmaps must be little-endian on disk.
+ * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
+ *    single word in a bitmap may straddle two pages in the extent buffer.
+ */
+#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
+#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
+#define BITMAP_FIRST_BYTE_MASK(start) \
+	((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
+#define BITMAP_LAST_BYTE_MASK(nbits) \
+	(BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+
+struct btrfs_bio;
+struct btrfs_root;
+struct btrfs_inode;
+struct btrfs_fs_info;
+struct io_failure_record;
+struct extent_io_tree;
+
+int __init extent_buffer_init_cachep(void);
+void __cold extent_buffer_free_cachep(void);
+
+typedef void (submit_bio_hook_t)(struct inode *inode, struct bio *bio,
+					 int mirror_num,
+					 enum btrfs_compression_type compress_type);
+
+typedef blk_status_t (extent_submit_bio_start_t)(struct inode *inode,
+		struct bio *bio, u64 dio_file_offset);
+
+#define INLINE_EXTENT_BUFFER_PAGES     (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
+struct extent_buffer {
+	u64 start;
+	unsigned long len;
+	unsigned long bflags;
+	struct btrfs_fs_info *fs_info;
+	spinlock_t refs_lock;
+	atomic_t refs;
+	atomic_t io_pages;
+	int read_mirror;
+	struct rcu_head rcu_head;
+	pid_t lock_owner;
+	/* >= 0 if eb belongs to a log tree, -1 otherwise */
+	s8 log_index;
+
+	struct rw_semaphore lock;
+
+	struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
+	struct list_head release_list;
+#ifdef CONFIG_BTRFS_DEBUG
+	struct list_head leak_list;
+#endif
+};
+
+/*
+ * Structure to record how many bytes and which ranges are set/cleared
+ */
+struct extent_changeset {
+	/* How many bytes are set/cleared in this operation */
+	u64 bytes_changed;
+
+	/* Changed ranges */
+	struct ulist range_changed;
+};
+
+static inline void extent_changeset_init(struct extent_changeset *changeset)
+{
+	changeset->bytes_changed = 0;
+	ulist_init(&changeset->range_changed);
+}
+
+static inline struct extent_changeset *extent_changeset_alloc(void)
+{
+	struct extent_changeset *ret;
+
+	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
+	if (!ret)
+		return NULL;
+
+	extent_changeset_init(ret);
+	return ret;
+}
+
+static inline void extent_changeset_release(struct extent_changeset *changeset)
+{
+	if (!changeset)
+		return;
+	changeset->bytes_changed = 0;
+	ulist_release(&changeset->range_changed);
+}
+
+static inline void extent_changeset_free(struct extent_changeset *changeset)
+{
+	if (!changeset)
+		return;
+	extent_changeset_release(changeset);
+	kfree(changeset);
+}
+
+struct extent_map_tree;
+
+int try_release_extent_mapping(struct page *page, gfp_t mask);
+int try_release_extent_buffer(struct page *page);
+
+int btrfs_read_folio(struct file *file, struct folio *folio);
+int extent_write_locked_range(struct inode *inode, u64 start, u64 end);
+int extent_writepages(struct address_space *mapping,
+		      struct writeback_control *wbc);
+int btree_write_cache_pages(struct address_space *mapping,
+			    struct writeback_control *wbc);
+void extent_readahead(struct readahead_control *rac);
+int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
+		  u64 start, u64 len);
+int set_page_extent_mapped(struct page *page);
+void clear_page_extent_mapped(struct page *page);
+
+struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
+					  u64 start, u64 owner_root, int level);
+struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+						  u64 start, unsigned long len);
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+						u64 start);
+struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
+struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
+					 u64 start);
+void free_extent_buffer(struct extent_buffer *eb);
+void free_extent_buffer_stale(struct extent_buffer *eb);
+#define WAIT_NONE	0
+#define WAIT_COMPLETE	1
+#define WAIT_PAGE_LOCK	2
+int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
+			     int mirror_num);
+void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
+void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
+				u64 bytenr, u64 owner_root, u64 gen, int level);
+void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
+
+static inline int num_extent_pages(const struct extent_buffer *eb)
+{
+	/*
+	 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
+	 * sectorsize, it's just eb->len >> PAGE_SHIFT.
+	 *
+	 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
+	 * thus have to ensure we get at least one page.
+	 */
+	return (eb->len >> PAGE_SHIFT) ?: 1;
+}
+
+static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
+{
+	return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+}
+
+int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
+			 unsigned long start, unsigned long len);
+void read_extent_buffer(const struct extent_buffer *eb, void *dst,
+			unsigned long start,
+			unsigned long len);
+int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
+				       void __user *dst, unsigned long start,
+				       unsigned long len);
+void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
+void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
+		const void *src);
+void write_extent_buffer(const struct extent_buffer *eb, const void *src,
+			 unsigned long start, unsigned long len);
+void copy_extent_buffer_full(const struct extent_buffer *dst,
+			     const struct extent_buffer *src);
+void copy_extent_buffer(const struct extent_buffer *dst,
+			const struct extent_buffer *src,
+			unsigned long dst_offset, unsigned long src_offset,
+			unsigned long len);
+void memcpy_extent_buffer(const struct extent_buffer *dst,
+			  unsigned long dst_offset, unsigned long src_offset,
+			  unsigned long len);
+void memmove_extent_buffer(const struct extent_buffer *dst,
+			   unsigned long dst_offset, unsigned long src_offset,
+			   unsigned long len);
+void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
+			   unsigned long len);
+int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
+			   unsigned long pos);
+void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
+			      unsigned long pos, unsigned long len);
+void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
+				unsigned long start, unsigned long pos,
+				unsigned long len);
+void clear_extent_buffer_dirty(const struct extent_buffer *eb);
+bool set_extent_buffer_dirty(struct extent_buffer *eb);
+void set_extent_buffer_uptodate(struct extent_buffer *eb);
+void clear_extent_buffer_uptodate(struct extent_buffer *eb);
+int extent_buffer_under_io(const struct extent_buffer *eb);
+void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
+void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
+void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
+				  struct page *locked_page,
+				  u32 bits_to_clear, unsigned long page_ops);
+int extent_invalidate_folio(struct extent_io_tree *tree,
+			    struct folio *folio, size_t offset);
+
+int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
+
+void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
+int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
+
+/*
+ * When IO fails, either with EIO or csum verification fails, we
+ * try other mirrors that might have a good copy of the data.  This
+ * io_failure_record is used to record state as we go through all the
+ * mirrors.  If another mirror has good data, the sector is set up to date
+ * and things continue.  If a good mirror can't be found, the original
+ * bio end_io callback is called to indicate things have failed.
+ */
+struct io_failure_record {
+	/* Use rb_simple_node for search/insert */
+	struct {
+		struct rb_node rb_node;
+		u64 bytenr;
+	};
+	struct page *page;
+	u64 len;
+	u64 logical;
+	int this_mirror;
+	int failed_mirror;
+	int num_copies;
+};
+
+int btrfs_repair_one_sector(struct inode *inode, struct btrfs_bio *failed_bbio,
+			    u32 bio_offset, struct page *page, unsigned int pgoff,
+			    submit_bio_hook_t *submit_bio_hook);
+void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end);
+int btrfs_clean_io_failure(struct btrfs_inode *inode, u64 start,
+			   struct page *page, unsigned int pg_offset);
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+bool find_lock_delalloc_range(struct inode *inode,
+			     struct page *locked_page, u64 *start,
+			     u64 *end);
+#endif
+struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
+					       u64 start);
+
+#ifdef CONFIG_BTRFS_DEBUG
+void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
+#else
+#define btrfs_extent_buffer_leak_debug_check(fs_info)	do {} while (0)
+#endif
+
+#endif