1 /* 2 * Copyright (c) 2000,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #ifndef __XFS_EXTFREE_ITEM_H__ 19 #define __XFS_EXTFREE_ITEM_H__ 20 21 /* kernel only EFI/EFD definitions */ 22 23 struct xfs_mount; 24 struct kmem_zone; 25 26 /* 27 * Max number of extents in fast allocation path. 28 */ 29 #define XFS_EFI_MAX_FAST_EXTENTS 16 30 31 /* 32 * Define EFI flag bits. Manipulated by set/clear/test_bit operators. 33 */ 34 #define XFS_EFI_RECOVERED 1 35 36 /* 37 * This is the "extent free intention" log item. It is used to log the fact 38 * that some extents need to be free. It is used in conjunction with the 39 * "extent free done" log item described below. 40 * 41 * The EFI is reference counted so that it is not freed prior to both the EFI 42 * and EFD being committed and unpinned. This ensures the EFI is inserted into 43 * the AIL even in the event of out of order EFI/EFD processing. In other words, 44 * an EFI is born with two references: 45 * 46 * 1.) an EFI held reference to track EFI AIL insertion 47 * 2.) an EFD held reference to track EFD commit 48 * 49 * On allocation, both references are the responsibility of the caller. Once the 50 * EFI is added to and dirtied in a transaction, ownership of reference one 51 * transfers to the transaction. The reference is dropped once the EFI is 52 * inserted to the AIL or in the event of failure along the way (e.g., commit 53 * failure, log I/O error, etc.). Note that the caller remains responsible for 54 * the EFD reference under all circumstances to this point. The caller has no 55 * means to detect failure once the transaction is committed, however. 56 * Therefore, an EFD is required after this point, even in the event of 57 * unrelated failure. 58 * 59 * Once an EFD is allocated and dirtied in a transaction, reference two 60 * transfers to the transaction. The EFD reference is dropped once it reaches 61 * the unpin handler. Similar to the EFI, the reference also drops in the event 62 * of commit failure or log I/O errors. Note that the EFD is not inserted in the 63 * AIL, so at this point both the EFI and EFD are freed. 64 */ 65 typedef struct xfs_efi_log_item { 66 xfs_log_item_t efi_item; 67 atomic_t efi_refcount; 68 atomic_t efi_next_extent; 69 unsigned long efi_flags; /* misc flags */ 70 xfs_efi_log_format_t efi_format; 71 } xfs_efi_log_item_t; 72 73 /* 74 * This is the "extent free done" log item. It is used to log 75 * the fact that some extents earlier mentioned in an efi item 76 * have been freed. 77 */ 78 typedef struct xfs_efd_log_item { 79 xfs_log_item_t efd_item; 80 xfs_efi_log_item_t *efd_efip; 81 uint efd_next_extent; 82 xfs_efd_log_format_t efd_format; 83 } xfs_efd_log_item_t; 84 85 /* 86 * Max number of extents in fast allocation path. 87 */ 88 #define XFS_EFD_MAX_FAST_EXTENTS 16 89 90 extern struct kmem_zone *xfs_efi_zone; 91 extern struct kmem_zone *xfs_efd_zone; 92 93 xfs_efi_log_item_t *xfs_efi_init(struct xfs_mount *, uint); 94 xfs_efd_log_item_t *xfs_efd_init(struct xfs_mount *, xfs_efi_log_item_t *, 95 uint); 96 int xfs_efi_copy_format(xfs_log_iovec_t *buf, 97 xfs_efi_log_format_t *dst_efi_fmt); 98 void xfs_efi_item_free(xfs_efi_log_item_t *); 99 void xfs_efi_release(struct xfs_efi_log_item *); 100 101 #endif /* __XFS_EXTFREE_ITEM_H__ */ 102