blob: 6ed495ca7a311dd974e3a4359ca4ada94ec22aec [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
* Copyright (C) 2007 Oracle. All rights reserved.
#include <linux/hash.h>
#include <linux/refcount.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/compiler.h>
#include <linux/fscrypt.h>
#include <linux/lockdep.h>
#include <uapi/linux/btrfs_tree.h>
#include <trace/events/btrfs.h>
#include "block-rsv.h"
#include "btrfs_inode.h"
#include "extent_map.h"
#include "extent_io.h"
#include "extent-io-tree.h"
#include "ordered-data.h"
#include "delayed-inode.h"
struct extent_state;
struct posix_acl;
struct iov_iter;
struct writeback_control;
struct btrfs_root;
struct btrfs_fs_info;
struct btrfs_trans_handle;
* Since we search a directory based on f_pos (struct dir_context::pos) we have
* to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
* everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
* 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 {
* 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).
* 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.
* 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).
* 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.
/* Set when this inode is a free space inode. */
/* Set when there are no capabilities in XATTs for the inode. */
* Set if an error happened when doing a COW write before submitting a
* bio or during writeback. Used for both buffered writes and direct IO
* writes. This is to signal a fast fsync that it has to wait for
* ordered extents to complete and therefore not log extent maps that
* point to unwritten extents (when an ordered extent completes and it
* has the BTRFS_ORDERED_IOERR flag set, it drops extent maps in its
* range).
/* 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;
/* Cached value of inode property 'compression'. */
u8 prop_compress;
* Force compression on the file using the defrag ioctl, could be
* different from prop_compress and takes precedence if set.
u8 defrag_compress;
* 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 delalloc_bytes, new_delalloc_bytes,
* defrag_bytes, disk_i_size, outstanding_extents, csum_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;
* Keep track of where the inode has extent items mapped in order to
* make sure the i_size adjustments are accurate. Not required when the
* filesystem is NO_HOLES, the status can't be set while mounted as
* it's a mkfs-time feature.
struct extent_io_tree *file_extent_tree;
/* held while logging the inode in tree-log.c */
struct mutex log_mutex;
* 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. Protected by 'lock'.
unsigned outstanding_extents;
/* used to order data wrt metadata */
spinlock_t ordered_tree_lock;
struct rb_root ordered_tree;
struct rb_node *ordered_tree_last;
/* 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;
/* full 64 bit generation number, struct vfs_inode doesn't have a big
* enough field for this.
u64 generation;
* ID of the transaction handle that last modified this inode.
* Protected by 'lock'.
u64 last_trans;
* ID of the transaction that last logged this inode.
* Protected by 'lock'.
u64 logged_trans;
* Log transaction ID when this inode was last modified.
* Protected by 'lock'.
int last_sub_trans;
/* A local copy of root's last_log_commit. Protected by 'lock'. */
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. Protected by 'lock'.
u64 delalloc_bytes;
* The lowest possible index of the next dir index key which
* points to an inode that needs to be logged.
* This is used only for directories.
* Use the helpers btrfs_get_first_dir_index_to_log() and
* btrfs_set_first_dir_index_to_log() to access this field.
u64 first_dir_index_to_log;
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. Protected by 'lock'.
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. Protected by 'lock'.
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. Protected by 'lock'.
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. For an empty directory, this
* must be initialized to BTRFS_DIR_START_INDEX.
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. Protected by 'lock'.
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;
struct btrfs_block_rsv block_rsv;
struct btrfs_delayed_node *delayed_node;
/* File creation time. */
u64 i_otime_sec;
u32 i_otime_nsec;
/* Hook into fs_info->delayed_iputs */
struct list_head delayed_iput;
struct rw_semaphore i_mmap_lock;
struct inode vfs_inode;
static inline u64 btrfs_get_first_dir_index_to_log(const struct btrfs_inode *inode)
return READ_ONCE(inode->first_dir_index_to_log);
static inline void btrfs_set_first_dir_index_to_log(struct btrfs_inode *inode,
u64 index)
WRITE_ONCE(inode->first_dir_index_to_log, index);
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);
return (unsigned long)h;
#if BITS_PER_LONG == 32
* On 32 bit systems the i_ino of struct inode is 32 bits (unsigned long), so
* we use the inode's location objectid which is a u64 to avoid truncation.
static inline u64 btrfs_ino(const struct btrfs_inode *inode)
u64 ino = inode->location.objectid;
/* type == BTRFS_ROOT_ITEM_KEY: subvol dir */
if (inode->location.type == BTRFS_ROOT_ITEM_KEY)
ino = inode->vfs_inode.i_ino;
return ino;
static inline u64 btrfs_ino(const struct btrfs_inode *inode)
return inode->vfs_inode.i_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)
return test_bit(BTRFS_INODE_FREE_SPACE_INODE, &inode->runtime_flags);
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)
inode->outstanding_extents += mod;
if (btrfs_is_free_space_inode(inode))
trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
mod, inode->outstanding_extents);
* 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)
inode->last_sub_trans = inode->root->log_transid;
* Should be called while holding the inode's VFS lock in exclusive mode, or
* while holding the inode's mmap lock (struct btrfs_inode::i_mmap_lock) in
* either shared or exclusive mode, or in a context where no one else can access
* the inode concurrently (during inode creation or when loading an inode from
* disk).
static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
* The inode may have been part of a reflink operation in the last
* transaction that modified it, and then a fsync has reset the
* last_reflink_trans to avoid subsequent fsyncs in the same
* transaction to do unnecessary work. So update last_reflink_trans
* to the last_trans value (we have to be pessimistic and assume a
* reflink happened).
* The ->last_trans is protected by the inode's spinlock and we can
* have a concurrent ordered extent completion update it. Also set
* last_reflink_trans to ->last_trans only if the former is less than
* the later, because we can be called in a context where
* last_reflink_trans was set to the current transaction generation
* while ->last_trans was not yet updated in the current transaction,
* and therefore has a lower value.
if (inode->last_reflink_trans < inode->last_trans)
inode->last_reflink_trans = inode->last_trans;
static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
bool ret = false;
if (inode->logged_trans == generation &&
inode->last_sub_trans <= inode->last_log_commit &&
inode->last_sub_trans <= btrfs_get_root_last_log_commit(inode->root))
ret = true;
return ret;
* Check if the inode has flags compatible with compression
static inline bool btrfs_inode_can_compress(const struct btrfs_inode *inode)
if (inode->flags & BTRFS_INODE_NODATACOW ||
return false;
return true;
/* Array of bytes with variable length, hexadecimal format 0x1234 */
#define CSUM_FMT "0x%*phN"
#define CSUM_FMT_VALUE(size, bytes) size, bytes
int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
u32 pgoff, u8 *csum, const u8 * const csum_expected);
bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
u32 bio_offset, struct bio_vec *bv);
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes, bool nowait, bool strict);
void btrfs_del_delalloc_inode(struct btrfs_inode *inode);
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
const struct fscrypt_str *name);
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
const struct fscrypt_str *name, int add_backref, u64 index);
int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry);
int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
int front);
int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context);
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
bool in_reclaim_context);
int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state);
struct btrfs_new_inode_args {
/* Input */
struct inode *dir;
struct dentry *dentry;
struct inode *inode;
bool orphan;
bool subvol;
/* Output from btrfs_new_inode_prepare(), input to btrfs_create_new_inode(). */
struct posix_acl *default_acl;
struct posix_acl *acl;
struct fscrypt_name fname;
int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
unsigned int *trans_num_items);
int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_new_inode_args *args);
void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args);
struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
struct inode *dir);
void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *state,
u32 bits);
void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
struct extent_state *state, u32 bits);
void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state *new,
struct extent_state *other);
void btrfs_split_delalloc_extent(struct btrfs_inode *inode,
struct extent_state *orig, u64 split);
void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
void btrfs_evict_inode(struct inode *inode);
struct inode *btrfs_alloc_inode(struct super_block *sb);
void btrfs_destroy_inode(struct inode *inode);
void btrfs_free_inode(struct inode *inode);
int btrfs_drop_inode(struct inode *inode);
int __init btrfs_init_cachep(void);
void __cold btrfs_destroy_cachep(void);
struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
struct btrfs_root *root, struct btrfs_path *path);
struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root);
struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
struct page *page, u64 start, u64 len);
int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode);
int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode);
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct btrfs_inode *inode);
int btrfs_orphan_cleanup(struct btrfs_root *root);
int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size);
void btrfs_add_delayed_iput(struct btrfs_inode *inode);
void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info);
int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info);
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint);
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint);
int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
u64 start, u64 end, struct writeback_control *wbc);
int btrfs_writepage_cow_fixup(struct page *page);
int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
int compress_type);
int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
u64 file_offset, u64 disk_bytenr,
u64 disk_io_size,
struct page **pages);
ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
struct btrfs_ioctl_encoded_io_args *encoded);
ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
const struct btrfs_ioctl_encoded_io_args *encoded);
ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter,
size_t done_before);
struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
size_t done_before);
struct btrfs_inode *btrfs_find_first_inode(struct btrfs_root *root, u64 min_ino);
extern const struct dentry_operations btrfs_dentry_operations;
/* Inode locking type flags, by default the exclusive lock is taken. */
enum btrfs_ilock_type {
int btrfs_inode_lock(struct btrfs_inode *inode, unsigned int ilock_flags);
void btrfs_inode_unlock(struct btrfs_inode *inode, unsigned int ilock_flags);
void btrfs_update_inode_bytes(struct btrfs_inode *inode, const u64 add_bytes,
const u64 del_bytes);
void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end);