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Diffstat (limited to 'fs/xfs/xfs_extfree_item.h')
| -rw-r--r-- | fs/xfs/xfs_extfree_item.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h new file mode 100644 index 000000000..da6a5afa6 --- /dev/null +++ b/fs/xfs/xfs_extfree_item.h @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000,2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __XFS_EXTFREE_ITEM_H__ +#define __XFS_EXTFREE_ITEM_H__ + +/* kernel only EFI/EFD definitions */ + +struct xfs_mount; +struct kmem_cache; + +/* + * Max number of extents in fast allocation path. + */ +#define XFS_EFI_MAX_FAST_EXTENTS 16 + +/* + * This is the "extent free intention" log item. It is used to log the fact + * that some extents need to be free. It is used in conjunction with the + * "extent free done" log item described below. + * + * The EFI is reference counted so that it is not freed prior to both the EFI + * and EFD being committed and unpinned. This ensures the EFI is inserted into + * the AIL even in the event of out of order EFI/EFD processing. In other words, + * an EFI is born with two references: + * + * 1.) an EFI held reference to track EFI AIL insertion + * 2.) an EFD held reference to track EFD commit + * + * On allocation, both references are the responsibility of the caller. Once the + * EFI is added to and dirtied in a transaction, ownership of reference one + * transfers to the transaction. The reference is dropped once the EFI is + * inserted to the AIL or in the event of failure along the way (e.g., commit + * failure, log I/O error, etc.). Note that the caller remains responsible for + * the EFD reference under all circumstances to this point. The caller has no + * means to detect failure once the transaction is committed, however. + * Therefore, an EFD is required after this point, even in the event of + * unrelated failure. + * + * Once an EFD is allocated and dirtied in a transaction, reference two + * transfers to the transaction. The EFD reference is dropped once it reaches + * the unpin handler. Similar to the EFI, the reference also drops in the event + * of commit failure or log I/O errors. Note that the EFD is not inserted in the + * AIL, so at this point both the EFI and EFD are freed. + */ +struct xfs_efi_log_item { + struct xfs_log_item efi_item; + atomic_t efi_refcount; + atomic_t efi_next_extent; + xfs_efi_log_format_t efi_format; +}; + +static inline size_t +xfs_efi_log_item_sizeof( + unsigned int nr) +{ + return offsetof(struct xfs_efi_log_item, efi_format) + + xfs_efi_log_format_sizeof(nr); +} + +/* + * This is the "extent free done" log item. It is used to log + * the fact that some extents earlier mentioned in an efi item + * have been freed. + */ +struct xfs_efd_log_item { + struct xfs_log_item efd_item; + struct xfs_efi_log_item *efd_efip; + uint efd_next_extent; + xfs_efd_log_format_t efd_format; +}; + +static inline size_t +xfs_efd_log_item_sizeof( + unsigned int nr) +{ + return offsetof(struct xfs_efd_log_item, efd_format) + + xfs_efd_log_format_sizeof(nr); +} + +/* + * Max number of extents in fast allocation path. + */ +#define XFS_EFD_MAX_FAST_EXTENTS 16 + +extern struct kmem_cache *xfs_efi_cache; +extern struct kmem_cache *xfs_efd_cache; + +#endif /* __XFS_EXTFREE_ITEM_H__ */ |