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 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 }; 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 struct xfs_efd_log_item { 67 struct xfs_log_item efd_item; 68 struct xfs_efi_log_item *efd_efip; 69 uint efd_next_extent; 70 xfs_efd_log_format_t efd_format; 71 }; 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 struct xfs_efi_log_item *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(struct xfs_efi_log_item *); 85 void xfs_efi_release(struct xfs_efi_log_item *); 86 87 int xfs_efi_recover(struct xfs_efi_log_item *efip, 88 struct list_head *capture_list); 89 90 #endif /* __XFS_EXTFREE_ITEM_H__ */ 91