16f52b16cSGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
280c9f490SDarrick J. Wong /*
380c9f490SDarrick J. Wong * FS_IOC_GETFSMAP ioctl infrastructure.
480c9f490SDarrick J. Wong *
580c9f490SDarrick J. Wong * Copyright (C) 2017 Oracle. All Rights Reserved.
680c9f490SDarrick J. Wong *
780c9f490SDarrick J. Wong * Author: Darrick J. Wong <darrick.wong@oracle.com>
880c9f490SDarrick J. Wong */
980c9f490SDarrick J. Wong #ifndef _LINUX_FSMAP_H
1080c9f490SDarrick J. Wong #define _LINUX_FSMAP_H
1180c9f490SDarrick J. Wong
1280c9f490SDarrick J. Wong #include <linux/types.h>
1380c9f490SDarrick J. Wong
1480c9f490SDarrick J. Wong /*
1580c9f490SDarrick J. Wong * Structure for FS_IOC_GETFSMAP.
1680c9f490SDarrick J. Wong *
1780c9f490SDarrick J. Wong * The memory layout for this call are the scalar values defined in
1880c9f490SDarrick J. Wong * struct fsmap_head, followed by two struct fsmap that describe
1980c9f490SDarrick J. Wong * the lower and upper bound of mappings to return, followed by an
2080c9f490SDarrick J. Wong * array of struct fsmap mappings.
2180c9f490SDarrick J. Wong *
2280c9f490SDarrick J. Wong * fmh_iflags control the output of the call, whereas fmh_oflags report
2380c9f490SDarrick J. Wong * on the overall record output. fmh_count should be set to the
2480c9f490SDarrick J. Wong * length of the fmh_recs array, and fmh_entries will be set to the
2580c9f490SDarrick J. Wong * number of entries filled out during each call. If fmh_count is
2680c9f490SDarrick J. Wong * zero, the number of reverse mappings will be returned in
2780c9f490SDarrick J. Wong * fmh_entries, though no mappings will be returned. fmh_reserved
2880c9f490SDarrick J. Wong * must be set to zero.
2980c9f490SDarrick J. Wong *
3080c9f490SDarrick J. Wong * The two elements in the fmh_keys array are used to constrain the
3180c9f490SDarrick J. Wong * output. The first element in the array should represent the
3280c9f490SDarrick J. Wong * lowest disk mapping ("low key") that the user wants to learn
3380c9f490SDarrick J. Wong * about. If this value is all zeroes, the filesystem will return
3480c9f490SDarrick J. Wong * the first entry it knows about. For a subsequent call, the
3580c9f490SDarrick J. Wong * contents of fsmap_head.fmh_recs[fsmap_head.fmh_count - 1] should be
3680c9f490SDarrick J. Wong * copied into fmh_keys[0] to have the kernel start where it left off.
3780c9f490SDarrick J. Wong *
3880c9f490SDarrick J. Wong * The second element in the fmh_keys array should represent the
3980c9f490SDarrick J. Wong * highest disk mapping ("high key") that the user wants to learn
4080c9f490SDarrick J. Wong * about. If this value is all ones, the filesystem will not stop
4180c9f490SDarrick J. Wong * until it runs out of mapping to return or runs out of space in
4280c9f490SDarrick J. Wong * fmh_recs.
4380c9f490SDarrick J. Wong *
4480c9f490SDarrick J. Wong * fmr_device can be either a 32-bit cookie representing a device, or
4580c9f490SDarrick J. Wong * a 32-bit dev_t if the FMH_OF_DEV_T flag is set. fmr_physical,
4680c9f490SDarrick J. Wong * fmr_offset, and fmr_length are expressed in units of bytes.
4780c9f490SDarrick J. Wong * fmr_owner is either an inode number, or a special value if
4880c9f490SDarrick J. Wong * FMR_OF_SPECIAL_OWNER is set in fmr_flags.
4980c9f490SDarrick J. Wong */
5080c9f490SDarrick J. Wong struct fsmap {
5180c9f490SDarrick J. Wong __u32 fmr_device; /* device id */
5280c9f490SDarrick J. Wong __u32 fmr_flags; /* mapping flags */
5380c9f490SDarrick J. Wong __u64 fmr_physical; /* device offset of segment */
5480c9f490SDarrick J. Wong __u64 fmr_owner; /* owner id */
5580c9f490SDarrick J. Wong __u64 fmr_offset; /* file offset of segment */
5680c9f490SDarrick J. Wong __u64 fmr_length; /* length of segment */
5780c9f490SDarrick J. Wong __u64 fmr_reserved[3]; /* must be zero */
5880c9f490SDarrick J. Wong };
5980c9f490SDarrick J. Wong
6080c9f490SDarrick J. Wong struct fsmap_head {
6180c9f490SDarrick J. Wong __u32 fmh_iflags; /* control flags */
6280c9f490SDarrick J. Wong __u32 fmh_oflags; /* output flags */
6380c9f490SDarrick J. Wong __u32 fmh_count; /* # of entries in array incl. input */
6480c9f490SDarrick J. Wong __u32 fmh_entries; /* # of entries filled in (output). */
6580c9f490SDarrick J. Wong __u64 fmh_reserved[6]; /* must be zero */
6680c9f490SDarrick J. Wong
6780c9f490SDarrick J. Wong struct fsmap fmh_keys[2]; /* low and high keys for the mapping search */
6880c9f490SDarrick J. Wong struct fsmap fmh_recs[]; /* returned records */
6980c9f490SDarrick J. Wong };
7080c9f490SDarrick J. Wong
7180c9f490SDarrick J. Wong /* Size of an fsmap_head with room for nr records. */
72*cbf28203SMasahiro Yamada static inline __kernel_size_t
fsmap_sizeof(unsigned int nr)7380c9f490SDarrick J. Wong fsmap_sizeof(
7480c9f490SDarrick J. Wong unsigned int nr)
7580c9f490SDarrick J. Wong {
7680c9f490SDarrick J. Wong return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap);
7780c9f490SDarrick J. Wong }
7880c9f490SDarrick J. Wong
7980c9f490SDarrick J. Wong /* Start the next fsmap query at the end of the current query results. */
8080c9f490SDarrick J. Wong static inline void
fsmap_advance(struct fsmap_head * head)8180c9f490SDarrick J. Wong fsmap_advance(
8280c9f490SDarrick J. Wong struct fsmap_head *head)
8380c9f490SDarrick J. Wong {
8480c9f490SDarrick J. Wong head->fmh_keys[0] = head->fmh_recs[head->fmh_entries - 1];
8580c9f490SDarrick J. Wong }
8680c9f490SDarrick J. Wong
8780c9f490SDarrick J. Wong /* fmh_iflags values - set by FS_IOC_GETFSMAP caller in the header. */
8880c9f490SDarrick J. Wong /* no flags defined yet */
8980c9f490SDarrick J. Wong #define FMH_IF_VALID 0
9080c9f490SDarrick J. Wong
9180c9f490SDarrick J. Wong /* fmh_oflags values - returned in the header segment only. */
9280c9f490SDarrick J. Wong #define FMH_OF_DEV_T 0x1 /* fmr_device values will be dev_t */
9380c9f490SDarrick J. Wong
9480c9f490SDarrick J. Wong /* fmr_flags values - returned for each non-header segment */
9580c9f490SDarrick J. Wong #define FMR_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */
9680c9f490SDarrick J. Wong #define FMR_OF_ATTR_FORK 0x2 /* segment = attribute fork */
9780c9f490SDarrick J. Wong #define FMR_OF_EXTENT_MAP 0x4 /* segment = extent map */
9880c9f490SDarrick J. Wong #define FMR_OF_SHARED 0x8 /* segment = shared with another file */
9980c9f490SDarrick J. Wong #define FMR_OF_SPECIAL_OWNER 0x10 /* owner is a special value */
100d897246dSDarrick J. Wong #define FMR_OF_LAST 0x20 /* segment is the last in the dataset */
10180c9f490SDarrick J. Wong
10280c9f490SDarrick J. Wong /* Each FS gets to define its own special owner codes. */
10380c9f490SDarrick J. Wong #define FMR_OWNER(type, code) (((__u64)type << 32) | \
10480c9f490SDarrick J. Wong ((__u64)code & 0xFFFFFFFFULL))
10580c9f490SDarrick J. Wong #define FMR_OWNER_TYPE(owner) ((__u32)((__u64)owner >> 32))
10680c9f490SDarrick J. Wong #define FMR_OWNER_CODE(owner) ((__u32)(((__u64)owner & 0xFFFFFFFFULL)))
10780c9f490SDarrick J. Wong #define FMR_OWN_FREE FMR_OWNER(0, 1) /* free space */
10880c9f490SDarrick J. Wong #define FMR_OWN_UNKNOWN FMR_OWNER(0, 2) /* unknown owner */
10980c9f490SDarrick J. Wong #define FMR_OWN_METADATA FMR_OWNER(0, 3) /* metadata */
11080c9f490SDarrick J. Wong
11180c9f490SDarrick J. Wong #define FS_IOC_GETFSMAP _IOWR('X', 59, struct fsmap_head)
11280c9f490SDarrick J. Wong
11380c9f490SDarrick J. Wong #endif /* _LINUX_FSMAP_H */
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