/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* * FS_IOC_GETFSMAP ioctl infrastructure. * * Copyright (C) 2017 Oracle. All Rights Reserved. * * Author: Darrick J. Wong <[email protected]> */ #ifndef _LINUX_FSMAP_H #define _LINUX_FSMAP_H #include <linux/types.h> /* * Structure for FS_IOC_GETFSMAP. * * The memory layout for this call are the scalar values defined in * struct fsmap_head, followed by two struct fsmap that describe * the lower and upper bound of mappings to return, followed by an * array of struct fsmap mappings. * * fmh_iflags control the output of the call, whereas fmh_oflags report * on the overall record output. fmh_count should be set to the * length of the fmh_recs array, and fmh_entries will be set to the * number of entries filled out during each call. If fmh_count is * zero, the number of reverse mappings will be returned in * fmh_entries, though no mappings will be returned. fmh_reserved * must be set to zero. * * The two elements in the fmh_keys array are used to constrain the * output. The first element in the array should represent the * lowest disk mapping ("low key") that the user wants to learn * about. If this value is all zeroes, the filesystem will return * the first entry it knows about. For a subsequent call, the * contents of fsmap_head.fmh_recs[fsmap_head.fmh_count - 1] should be * copied into fmh_keys[0] to have the kernel start where it left off. * * The second element in the fmh_keys array should represent the * highest disk mapping ("high key") that the user wants to learn * about. If this value is all ones, the filesystem will not stop * until it runs out of mapping to return or runs out of space in * fmh_recs. * * fmr_device can be either a 32-bit cookie representing a device, or * a 32-bit dev_t if the FMH_OF_DEV_T flag is set. fmr_physical, * fmr_offset, and fmr_length are expressed in units of bytes. * fmr_owner is either an inode number, or a special value if * FMR_OF_SPECIAL_OWNER is set in fmr_flags. */ struct fsmap { … }; struct fsmap_head { … }; /* Size of an fsmap_head with room for nr records. */ static inline __kernel_size_t fsmap_sizeof( unsigned int nr) { … } /* Start the next fsmap query at the end of the current query results. */ static inline void fsmap_advance( struct fsmap_head *head) { … } /* fmh_iflags values - set by FS_IOC_GETFSMAP caller in the header. */ /* no flags defined yet */ #define FMH_IF_VALID … /* fmh_oflags values - returned in the header segment only. */ #define FMH_OF_DEV_T … /* fmr_flags values - returned for each non-header segment */ #define FMR_OF_PREALLOC … #define FMR_OF_ATTR_FORK … #define FMR_OF_EXTENT_MAP … #define FMR_OF_SHARED … #define FMR_OF_SPECIAL_OWNER … #define FMR_OF_LAST … /* Each FS gets to define its own special owner codes. */ #define FMR_OWNER(type, code) … #define FMR_OWNER_TYPE(owner) … #define FMR_OWNER_CODE(owner) … #define FMR_OWN_FREE … #define FMR_OWN_UNKNOWN … #define FMR_OWN_METADATA … #define FS_IOC_GETFSMAP … #endif /* _LINUX_FSMAP_H */
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