1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6 #ifndef __XFS_EXTFREE_ITEM_H__
7 #define __XFS_EXTFREE_ITEM_H__
8
9 /* kernel only EFI/EFD definitions */
10
11 struct xfs_mount;
12 struct kmem_zone;
13
14 /*
15 * Max number of extents in fast allocation path.
16 */
17 #define XFS_EFI_MAX_FAST_EXTENTS 16
18
19 /*
20 * Define EFI flag bits. Manipulated by set/clear/test_bit operators.
21 */
22 #define XFS_EFI_RECOVERED 1
23
24 /*
25 * This is the "extent free intention" log item. It is used to log the fact
26 * that some extents need to be free. It is used in conjunction with the
27 * "extent free done" log item described below.
28 *
29 * The EFI is reference counted so that it is not freed prior to both the EFI
30 * and EFD being committed and unpinned. This ensures the EFI is inserted into
31 * the AIL even in the event of out of order EFI/EFD processing. In other words,
32 * an EFI is born with two references:
33 *
34 * 1.) an EFI held reference to track EFI AIL insertion
35 * 2.) an EFD held reference to track EFD commit
36 *
37 * On allocation, both references are the responsibility of the caller. Once the
38 * EFI is added to and dirtied in a transaction, ownership of reference one
39 * transfers to the transaction. The reference is dropped once the EFI is
40 * inserted to the AIL or in the event of failure along the way (e.g., commit
41 * failure, log I/O error, etc.). Note that the caller remains responsible for
42 * the EFD reference under all circumstances to this point. The caller has no
43 * means to detect failure once the transaction is committed, however.
44 * Therefore, an EFD is required after this point, even in the event of
45 * unrelated failure.
46 *
47 * Once an EFD is allocated and dirtied in a transaction, reference two
48 * transfers to the transaction. The EFD reference is dropped once it reaches
49 * the unpin handler. Similar to the EFI, the reference also drops in the event
50 * of commit failure or log I/O errors. Note that the EFD is not inserted in the
51 * AIL, so at this point both the EFI and EFD are freed.
52 */
53 typedef struct xfs_efi_log_item {
54 struct xfs_log_item efi_item;
55 atomic_t efi_refcount;
56 atomic_t efi_next_extent;
57 unsigned long efi_flags; /* misc flags */
58 xfs_efi_log_format_t efi_format;
59 } xfs_efi_log_item_t;
60
61 /*
62 * This is the "extent free done" log item. It is used to log
63 * the fact that some extents earlier mentioned in an efi item
64 * have been freed.
65 */
66 typedef struct xfs_efd_log_item {
67 struct xfs_log_item efd_item;
68 xfs_efi_log_item_t *efd_efip;
69 uint efd_next_extent;
70 xfs_efd_log_format_t efd_format;
71 } xfs_efd_log_item_t;
72
73 /*
74 * Max number of extents in fast allocation path.
75 */
76 #define XFS_EFD_MAX_FAST_EXTENTS 16
77
78 extern struct kmem_zone *xfs_efi_zone;
79 extern struct kmem_zone *xfs_efd_zone;
80
81 xfs_efi_log_item_t *xfs_efi_init(struct xfs_mount *, uint);
82 int xfs_efi_copy_format(xfs_log_iovec_t *buf,
83 xfs_efi_log_format_t *dst_efi_fmt);
84 void xfs_efi_item_free(xfs_efi_log_item_t *);
85 void xfs_efi_release(struct xfs_efi_log_item *);
86
87 int xfs_efi_recover(struct xfs_mount *mp,
88 struct xfs_efi_log_item *efip);
89
90 #endif /* __XFS_EXTFREE_ITEM_H__ */