fs/btrfs/btrfs_inode.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2007 Oracle.  All rights reserved.
  */

 #ifndef BTRFS_INODE_H
 #define BTRFS_INODE_H

 #include <linux/hash.h>
 #include <linux/refcount.h>
 #include "extent_map.h"
 #include "extent_io.h"
 #include "ordered-data.h"
 #include "delayed-inode.h"

 /*
  * 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.
  */
 enum {
 	BTRFS_INODE_FLUSH_ON_CLOSE,
 	BTRFS_INODE_DUMMY,
 	BTRFS_INODE_IN_DEFRAG,
 	BTRFS_INODE_HAS_ASYNC_EXTENT,
 	 /*
 	  * Always set under the VFS' inode lock, otherwise it can cause races
 	  * during fsync (we start as a fast fsync and then end up in a full
 	  * fsync racing with ordered extent completion).
 	  */
 	BTRFS_INODE_NEEDS_FULL_SYNC,
 	BTRFS_INODE_COPY_EVERYTHING,
 	BTRFS_INODE_IN_DELALLOC_LIST,
 	BTRFS_INODE_HAS_PROPS,
 	BTRFS_INODE_SNAPSHOT_FLUSH,
 	/*
 	 * Set and used when logging an inode and it serves to signal that an
 	 * inode does not have xattrs, so subsequent fsyncs can avoid searching
 	 * for xattrs to log. This bit must be cleared whenever a xattr is added
 	 * to an inode.
 	 */
 	BTRFS_INODE_NO_XATTRS,
 	/*
 	 * Set when we are in a context where we need to start a transaction and
 	 * have dirty pages with the respective file range locked. This is to
 	 * ensure that when reserving space for the transaction, if we are low
 	 * on available space and need to flush delalloc, we will not flush
 	 * delalloc for this inode, because that could result in a deadlock (on
 	 * the file range, inode's io_tree).
 	 */
 	BTRFS_INODE_NO_DELALLOC_FLUSH,
 	/*
 	 * Set when we are working on enabling verity for a file. Computing and
 	 * writing the whole Merkle tree can take a while so we want to prevent
 	 * races where two separate tasks attempt to simultaneously start verity
 	 * on the same file.
 	 */
 	BTRFS_INODE_VERITY_IN_PROGRESS,
 };

 /* in memory btrfs inode */
 struct btrfs_inode {
 	/* which subvolume this inode belongs to */
 	struct btrfs_root *root;

 	/* key used to find this inode on disk.  This is used by the code
 	 * to read in roots of subvolumes
 	 */
 	struct btrfs_key location;

 	/*
 	 * Lock for counters and all fields used to determine if the inode is in
 	 * the log or not (last_trans, last_sub_trans, last_log_commit,
 	 * logged_trans), to access/update new_delalloc_bytes and to update the
 	 * VFS' inode number of bytes used.
 	 */
 	spinlock_t lock;

 	/* the extent_tree has caches of all the extent mappings to disk */
 	struct extent_map_tree extent_tree;

 	/* the io_tree does range state (DIRTY, LOCKED etc) */
 	struct extent_io_tree io_tree;

 	/* special utility tree used to record which mirrors have already been
 	 * tried when checksums fail for a given block
 	 */
 	struct extent_io_tree io_failure_tree;

 	/*
 	 * Keep track of where the inode has extent items mapped in order to
 	 * make sure the i_size adjustments are accurate
 	 */
 	struct extent_io_tree file_extent_tree;

 	/* held while logging the inode in tree-log.c */
 	struct mutex log_mutex;

 	/* used to order data wrt metadata */
 	struct btrfs_ordered_inode_tree ordered_tree;

 	/* list of all the delalloc inodes in the FS.  There are times we need
 	 * to write all the delalloc pages to disk, and this list is used
 	 * to walk them all.
 	 */
 	struct list_head delalloc_inodes;

 	/* node for the red-black tree that links inodes in subvolume root */
 	struct rb_node rb_node;

 	unsigned long runtime_flags;

 	/* Keep track of who's O_SYNC/fsyncing currently */
 	atomic_t sync_writers;

 	/* full 64 bit generation number, struct vfs_inode doesn't have a big
 	 * enough field for this.
 	 */
 	u64 generation;

 	/*
 	 * transid of the trans_handle that last modified this inode
 	 */
 	u64 last_trans;

 	/*
 	 * transid that last logged this inode
 	 */
 	u64 logged_trans;

 	/*
 	 * log transid when this inode was last modified
 	 */
 	int last_sub_trans;

 	/* a local copy of root's last_log_commit */
 	int last_log_commit;

 	union {
 		/*
 		 * Total number of bytes pending delalloc, used by stat to
 		 * calculate the real block usage of the file. This is used
 		 * only for files.
 		 */
 		u64 delalloc_bytes;
 		/*
 		 * The offset of the last dir item key that was logged.
 		 * This is used only for directories.
 		 */
 		u64 last_dir_item_offset;
 	};

 	union {
 		/*
 		 * Total number of bytes pending delalloc that fall within a file
 		 * range that is either a hole or beyond EOF (and no prealloc extent
 		 * exists in the range). This is always <= delalloc_bytes and this
 		 * is used only for files.
 		 */
 		u64 new_delalloc_bytes;
 		/*
 		 * The offset of the last dir index key that was logged.
 		 * This is used only for directories.
 		 */
 		u64 last_dir_index_offset;
 	};

 	/*
 	 * total number of bytes pending defrag, used by stat to check whether
 	 * it needs COW.
 	 */
 	u64 defrag_bytes;

 	/*
 	 * the size of the file stored in the metadata on disk.  data=ordered
 	 * means the in-memory i_size might be larger than the size on disk
 	 * because not all the blocks are written yet.
 	 */
 	u64 disk_i_size;

 	/*
 	 * if this is a directory then index_cnt is the counter for the index
 	 * number for new files that are created
 	 */
 	u64 index_cnt;

 	/* Cache the directory index number to speed the dir/file remove */
 	u64 dir_index;

 	/* the fsync log has some corner cases that mean we have to check
 	 * directories to see if any unlinks have been done before
 	 * the directory was logged.  See tree-log.c for all the
 	 * details
 	 */
 	u64 last_unlink_trans;

 	/*
 	 * The id/generation of the last transaction where this inode was
 	 * either the source or the destination of a clone/dedupe operation.
 	 * Used when logging an inode to know if there are shared extents that
 	 * need special care when logging checksum items, to avoid duplicate
 	 * checksum items in a log (which can lead to a corruption where we end
 	 * up with missing checksum ranges after log replay).
 	 * Protected by the vfs inode lock.
 	 */
 	u64 last_reflink_trans;

 	/*
 	 * Number of bytes outstanding that are going to need csums.  This is
 	 * used in ENOSPC accounting.
 	 */
 	u64 csum_bytes;

 	/* Backwards incompatible flags, lower half of inode_item::flags  */
 	u32 flags;
 	/* Read-only compatibility flags, upper half of inode_item::flags */
 	u32 ro_flags;

 	/*
 	 * Counters to keep track of the number of extent item's we may use due
 	 * to delalloc and such.  outstanding_extents is the number of extent
 	 * items we think we'll end up using, and reserved_extents is the number
 	 * of extent items we've reserved metadata for.
 	 */
 	unsigned outstanding_extents;

 	struct btrfs_block_rsv block_rsv;

 	/*
 	 * Cached values of inode properties
 	 */
 	unsigned prop_compress;		/* per-file compression algorithm */
 	/*
 	 * Force compression on the file using the defrag ioctl, could be
 	 * different from prop_compress and takes precedence if set
 	 */
 	unsigned defrag_compress;

 	struct btrfs_delayed_node *delayed_node;

 	/* File creation time. */
 	struct timespec64 i_otime;

 	/* Hook into fs_info->delayed_iputs */
 	struct list_head delayed_iput;

 	struct rw_semaphore i_mmap_lock;
 	struct inode vfs_inode;
 };

 static inline u32 btrfs_inode_sectorsize(const struct btrfs_inode *inode)
 {
 	return inode->root->fs_info->sectorsize;
 }

 static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
 {
 	return container_of(inode, struct btrfs_inode, vfs_inode);
 }

 static inline unsigned long btrfs_inode_hash(u64 objectid,
 					     const struct btrfs_root *root)
 {
 	u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);

 #if BITS_PER_LONG == 32
 	h = (h >> 32) ^ (h & 0xffffffff);
 #endif

 	return (unsigned long)h;
 }

 static inline void btrfs_insert_inode_hash(struct inode *inode)
 {
 	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);

 	__insert_inode_hash(inode, h);
 }

 static inline u64 btrfs_ino(const struct btrfs_inode *inode)
 {
 	u64 ino = inode->location.objectid;

 	/*
 	 * !ino: btree_inode
 	 * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 	 */
 	if (!ino || inode->location.type == BTRFS_ROOT_ITEM_KEY)
 		ino = inode->vfs_inode.i_ino;
 	return ino;
 }

 static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
 {
 	i_size_write(&inode->vfs_inode, size);
 	inode->disk_i_size = size;
 }

 static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
 {
 	struct btrfs_root *root = inode->root;

 	if (root == root->fs_info->tree_root &&
 	    btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
 		return true;
 	if (inode->location.objectid == BTRFS_FREE_INO_OBJECTID)
 		return true;
 	return false;
 }

 static inline bool is_data_inode(struct inode *inode)
 {
 	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
 }

 static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
 						 int mod)
 {
 	lockdep_assert_held(&inode->lock);
 	inode->outstanding_extents += mod;
 	if (btrfs_is_free_space_inode(inode))
 		return;
 	trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
 						  mod);
 }

 /*
  * Called every time after doing a buffered, direct IO or memory mapped write.
  *
  * This is to ensure that if we write to a file that was previously fsynced in
  * the current transaction, then try to fsync it again in the same transaction,
  * we will know that there were changes in the file and that it needs to be
  * logged.
  */
 static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
 {
 	spin_lock(&inode->lock);
 	inode->last_sub_trans = inode->root->log_transid;
 	spin_unlock(&inode->lock);
 }

 static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
 {
 	bool ret = false;

 	spin_lock(&inode->lock);
 	if (inode->logged_trans == generation &&
 	    inode->last_sub_trans <= inode->last_log_commit &&
 	    inode->last_sub_trans <= inode->root->last_log_commit)
 		ret = true;
 	spin_unlock(&inode->lock);
 	return ret;
 }

 struct btrfs_dio_private {
 	struct inode *inode;

 	/*
 	 * Since DIO can use anonymous page, we cannot use page_offset() to
 	 * grab the file offset, thus need a dedicated member for file offset.
 	 */
 	u64 file_offset;
 	u64 disk_bytenr;
 	/* Used for bio::bi_size */
 	u32 bytes;

 	/*
 	 * References to this structure. There is one reference per in-flight
 	 * bio plus one while we're still setting up.
 	 */
 	refcount_t refs;

 	/* dio_bio came from fs/direct-io.c */
 	struct bio *dio_bio;

 	/* Array of checksums */
 	u8 csums[];
 };

 /*
  * btrfs_inode_item stores flags in a u64, btrfs_inode stores them in two
  * separate u32s. These two functions convert between the two representations.
  */
 static inline u64 btrfs_inode_combine_flags(u32 flags, u32 ro_flags)
 {
 	return (flags | ((u64)ro_flags << 32));
 }

 static inline void btrfs_inode_split_flags(u64 inode_item_flags,
 					   u32 *flags, u32 *ro_flags)
 {
 	*flags = (u32)inode_item_flags;
 	*ro_flags = (u32)(inode_item_flags >> 32);
 }

 /* Array of bytes with variable length, hexadecimal format 0x1234 */
 #define CSUM_FMT				"0x%*phN"
 #define CSUM_FMT_VALUE(size, bytes)		size, bytes

 static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
 		u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
 {
 	struct btrfs_root *root = inode->root;
 	const u32 csum_size = root->fs_info->csum_size;

 	/* Output minus objectid, which is more meaningful */
 	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
 		btrfs_warn_rl(root->fs_info,
 "csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
 			root->root_key.objectid, btrfs_ino(inode),
 			logical_start,
 			CSUM_FMT_VALUE(csum_size, csum),
 			CSUM_FMT_VALUE(csum_size, csum_expected),
 			mirror_num);
 	else
 		btrfs_warn_rl(root->fs_info,
 "csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
 			root->root_key.objectid, btrfs_ino(inode),
 			logical_start,
 			CSUM_FMT_VALUE(csum_size, csum),
 			CSUM_FMT_VALUE(csum_size, csum_expected),
 			mirror_num);
 }

 #endif
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* Copyright (C) 2007 Oracle. All rights reserved.
	*/

	#ifndef BTRFS_INODE_H
	#define BTRFS_INODE_H

	#include <linux/hash.h>
	#include <linux/refcount.h>
	#include "extent_map.h"
	#include "extent_io.h"
	#include "ordered-data.h"
	#include "delayed-inode.h"

	/*
	* 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.
	*/
	enum {
	BTRFS_INODE_FLUSH_ON_CLOSE,
	BTRFS_INODE_DUMMY,
	BTRFS_INODE_IN_DEFRAG,
	BTRFS_INODE_HAS_ASYNC_EXTENT,
	/*
	* Always set under the VFS' inode lock, otherwise it can cause races
	* during fsync (we start as a fast fsync and then end up in a full
	* fsync racing with ordered extent completion).
	*/
	BTRFS_INODE_NEEDS_FULL_SYNC,
	BTRFS_INODE_COPY_EVERYTHING,
	BTRFS_INODE_IN_DELALLOC_LIST,
	BTRFS_INODE_HAS_PROPS,
	BTRFS_INODE_SNAPSHOT_FLUSH,
	/*
	* Set and used when logging an inode and it serves to signal that an
	* inode does not have xattrs, so subsequent fsyncs can avoid searching
	* for xattrs to log. This bit must be cleared whenever a xattr is added
	* to an inode.
	*/
	BTRFS_INODE_NO_XATTRS,
	/*
	* Set when we are in a context where we need to start a transaction and
	* have dirty pages with the respective file range locked. This is to
	* ensure that when reserving space for the transaction, if we are low
	* on available space and need to flush delalloc, we will not flush
	* delalloc for this inode, because that could result in a deadlock (on
	* the file range, inode's io_tree).
	*/
	BTRFS_INODE_NO_DELALLOC_FLUSH,
	/*
	* Set when we are working on enabling verity for a file. Computing and
	* writing the whole Merkle tree can take a while so we want to prevent
	* races where two separate tasks attempt to simultaneously start verity
	* on the same file.
	*/
	BTRFS_INODE_VERITY_IN_PROGRESS,
	};

	/* in memory btrfs inode */
	struct btrfs_inode {
	/* which subvolume this inode belongs to */
	struct btrfs_root *root;

	/* key used to find this inode on disk. This is used by the code
	* to read in roots of subvolumes
	*/
	struct btrfs_key location;

	/*
	* Lock for counters and all fields used to determine if the inode is in
	* the log or not (last_trans, last_sub_trans, last_log_commit,
	* logged_trans), to access/update new_delalloc_bytes and to update the
	* VFS' inode number of bytes used.
	*/
	spinlock_t lock;

	/* the extent_tree has caches of all the extent mappings to disk */
	struct extent_map_tree extent_tree;

	/* the io_tree does range state (DIRTY, LOCKED etc) */
	struct extent_io_tree io_tree;

	/* special utility tree used to record which mirrors have already been
	* tried when checksums fail for a given block
	*/
	struct extent_io_tree io_failure_tree;

	/*
	* Keep track of where the inode has extent items mapped in order to
	* make sure the i_size adjustments are accurate
	*/
	struct extent_io_tree file_extent_tree;

	/* held while logging the inode in tree-log.c */
	struct mutex log_mutex;

	/* used to order data wrt metadata */
	struct btrfs_ordered_inode_tree ordered_tree;

	/* list of all the delalloc inodes in the FS. There are times we need
	* to write all the delalloc pages to disk, and this list is used
	* to walk them all.
	*/
	struct list_head delalloc_inodes;

	/* node for the red-black tree that links inodes in subvolume root */
	struct rb_node rb_node;

	unsigned long runtime_flags;

	/* Keep track of who's O_SYNC/fsyncing currently */
	atomic_t sync_writers;

	/* full 64 bit generation number, struct vfs_inode doesn't have a big
	* enough field for this.
	*/
	u64 generation;

	/*
	* transid of the trans_handle that last modified this inode
	*/
	u64 last_trans;

	/*
	* transid that last logged this inode
	*/
	u64 logged_trans;

	/*
	* log transid when this inode was last modified
	*/
	int last_sub_trans;

	/* a local copy of root's last_log_commit */
	int last_log_commit;

	union {
	/*
	* Total number of bytes pending delalloc, used by stat to
	* calculate the real block usage of the file. This is used
	* only for files.
	*/
	u64 delalloc_bytes;
	/*
	* The offset of the last dir item key that was logged.
	* This is used only for directories.
	*/
	u64 last_dir_item_offset;
	};

	union {
	/*
	* Total number of bytes pending delalloc that fall within a file
	* range that is either a hole or beyond EOF (and no prealloc extent
	* exists in the range). This is always <= delalloc_bytes and this
	* is used only for files.
	*/
	u64 new_delalloc_bytes;
	/*
	* The offset of the last dir index key that was logged.
	* This is used only for directories.
	*/
	u64 last_dir_index_offset;
	};

	/*
	* total number of bytes pending defrag, used by stat to check whether
	* it needs COW.
	*/
	u64 defrag_bytes;

	/*
	* the size of the file stored in the metadata on disk. data=ordered
	* means the in-memory i_size might be larger than the size on disk
	* because not all the blocks are written yet.
	*/
	u64 disk_i_size;

	/*
	* if this is a directory then index_cnt is the counter for the index
	* number for new files that are created
	*/
	u64 index_cnt;

	/* Cache the directory index number to speed the dir/file remove */
	u64 dir_index;

	/* the fsync log has some corner cases that mean we have to check
	* directories to see if any unlinks have been done before
	* the directory was logged. See tree-log.c for all the
	* details
	*/
	u64 last_unlink_trans;

	/*
	* The id/generation of the last transaction where this inode was
	* either the source or the destination of a clone/dedupe operation.
	* Used when logging an inode to know if there are shared extents that
	* need special care when logging checksum items, to avoid duplicate
	* checksum items in a log (which can lead to a corruption where we end
	* up with missing checksum ranges after log replay).
	* Protected by the vfs inode lock.
	*/
	u64 last_reflink_trans;

	/*
	* Number of bytes outstanding that are going to need csums. This is
	* used in ENOSPC accounting.
	*/
	u64 csum_bytes;

	/* Backwards incompatible flags, lower half of inode_item::flags */
	u32 flags;
	/* Read-only compatibility flags, upper half of inode_item::flags */
	u32 ro_flags;

	/*
	* Counters to keep track of the number of extent item's we may use due
	* to delalloc and such. outstanding_extents is the number of extent
	* items we think we'll end up using, and reserved_extents is the number
	* of extent items we've reserved metadata for.
	*/
	unsigned outstanding_extents;

	struct btrfs_block_rsv block_rsv;

	/*
	* Cached values of inode properties
	*/
	unsigned prop_compress; /* per-file compression algorithm */
	/*
	* Force compression on the file using the defrag ioctl, could be
	* different from prop_compress and takes precedence if set
	*/
	unsigned defrag_compress;

	struct btrfs_delayed_node *delayed_node;

	/* File creation time. */
	struct timespec64 i_otime;

	/* Hook into fs_info->delayed_iputs */
	struct list_head delayed_iput;

	struct rw_semaphore i_mmap_lock;
	struct inode vfs_inode;
	};

	static inline u32 btrfs_inode_sectorsize(const struct btrfs_inode *inode)
	{
	return inode->root->fs_info->sectorsize;
	}

	static inline struct btrfs_inode BTRFS_I(const struct inode inode)
	{
	return container_of(inode, struct btrfs_inode, vfs_inode);
	}

	static inline unsigned long btrfs_inode_hash(u64 objectid,
	const struct btrfs_root *root)
	{
	u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);

	#if BITS_PER_LONG == 32
	h = (h >> 32) ^ (h & 0xffffffff);
	#endif

	return (unsigned long)h;
	}

	static inline void btrfs_insert_inode_hash(struct inode *inode)
	{
	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);

	__insert_inode_hash(inode, h);
	}

	static inline u64 btrfs_ino(const struct btrfs_inode *inode)
	{
	u64 ino = inode->location.objectid;

	/*
	* !ino: btree_inode
	* type == BTRFS_ROOT_ITEM_KEY: subvol dir
	*/
	if (!ino \|\| inode->location.type == BTRFS_ROOT_ITEM_KEY)
	ino = inode->vfs_inode.i_ino;
	return ino;
	}

	static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
	{
	i_size_write(&inode->vfs_inode, size);
	inode->disk_i_size = size;
	}

	static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
	{
	struct btrfs_root *root = inode->root;

	if (root == root->fs_info->tree_root &&
	btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
	return true;
	if (inode->location.objectid == BTRFS_FREE_INO_OBJECTID)
	return true;
	return false;
	}

	static inline bool is_data_inode(struct inode *inode)
	{
	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
	}

	static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
	int mod)
	{
	lockdep_assert_held(&inode->lock);
	inode->outstanding_extents += mod;
	if (btrfs_is_free_space_inode(inode))
	return;
	trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
	mod);
	}

	/*
	* Called every time after doing a buffered, direct IO or memory mapped write.
	*
	* This is to ensure that if we write to a file that was previously fsynced in
	* the current transaction, then try to fsync it again in the same transaction,
	* we will know that there were changes in the file and that it needs to be
	* logged.
	*/
	static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
	{
	spin_lock(&inode->lock);
	inode->last_sub_trans = inode->root->log_transid;
	spin_unlock(&inode->lock);
	}

	static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
	{
	bool ret = false;

	spin_lock(&inode->lock);
	if (inode->logged_trans == generation &&
	inode->last_sub_trans <= inode->last_log_commit &&
	inode->last_sub_trans <= inode->root->last_log_commit)
	ret = true;
	spin_unlock(&inode->lock);
	return ret;
	}

	struct btrfs_dio_private {
	struct inode *inode;

	/*
	* Since DIO can use anonymous page, we cannot use page_offset() to
	* grab the file offset, thus need a dedicated member for file offset.
	*/
	u64 file_offset;
	u64 disk_bytenr;
	/* Used for bio::bi_size */
	u32 bytes;

	/*
	* References to this structure. There is one reference per in-flight
	* bio plus one while we're still setting up.
	*/
	refcount_t refs;

	/* dio_bio came from fs/direct-io.c */
	struct bio *dio_bio;

	/* Array of checksums */
	u8 csums[];
	};

	/*
	* btrfs_inode_item stores flags in a u64, btrfs_inode stores them in two
	* separate u32s. These two functions convert between the two representations.
	*/
	static inline u64 btrfs_inode_combine_flags(u32 flags, u32 ro_flags)
	{
	return (flags \| ((u64)ro_flags << 32));
	}

	static inline void btrfs_inode_split_flags(u64 inode_item_flags,
	u32 flags, u32 ro_flags)
	{
	*flags = (u32)inode_item_flags;
	*ro_flags = (u32)(inode_item_flags >> 32);
	}

	/* Array of bytes with variable length, hexadecimal format 0x1234 */
	#define CSUM_FMT "0x%*phN"
	#define CSUM_FMT_VALUE(size, bytes) size, bytes

	static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
	u64 logical_start, u8 csum, u8 csum_expected, int mirror_num)
	{
	struct btrfs_root *root = inode->root;
	const u32 csum_size = root->fs_info->csum_size;

	/* Output minus objectid, which is more meaningful */
	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
	btrfs_warn_rl(root->fs_info,
	"csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
	root->root_key.objectid, btrfs_ino(inode),
	logical_start,
	CSUM_FMT_VALUE(csum_size, csum),
	CSUM_FMT_VALUE(csum_size, csum_expected),
	mirror_num);
	else
	btrfs_warn_rl(root->fs_info,
	"csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
	root->root_key.objectid, btrfs_ino(inode),
	logical_start,
	CSUM_FMT_VALUE(csum_size, csum),
	CSUM_FMT_VALUE(csum_size, csum_expected),
	mirror_num);
	}

	#endif