| /* 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 <darrick.wong@oracle.com> |
| */ |
| #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 { |
| __u32 fmr_device; /* device id */ |
| __u32 fmr_flags; /* mapping flags */ |
| __u64 fmr_physical; /* device offset of segment */ |
| __u64 fmr_owner; /* owner id */ |
| __u64 fmr_offset; /* file offset of segment */ |
| __u64 fmr_length; /* length of segment */ |
| __u64 fmr_reserved[3]; /* must be zero */ |
| }; |
| |
| struct fsmap_head { |
| __u32 fmh_iflags; /* control flags */ |
| __u32 fmh_oflags; /* output flags */ |
| __u32 fmh_count; /* # of entries in array incl. input */ |
| __u32 fmh_entries; /* # of entries filled in (output). */ |
| __u64 fmh_reserved[6]; /* must be zero */ |
| |
| struct fsmap fmh_keys[2]; /* low and high keys for the mapping search */ |
| struct fsmap fmh_recs[]; /* returned records */ |
| }; |
| |
| /* Size of an fsmap_head with room for nr records. */ |
| static inline __kernel_size_t |
| fsmap_sizeof( |
| unsigned int nr) |
| { |
| return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap); |
| } |
| |
| /* Start the next fsmap query at the end of the current query results. */ |
| static inline void |
| fsmap_advance( |
| struct fsmap_head *head) |
| { |
| head->fmh_keys[0] = head->fmh_recs[head->fmh_entries - 1]; |
| } |
| |
| /* fmh_iflags values - set by FS_IOC_GETFSMAP caller in the header. */ |
| /* no flags defined yet */ |
| #define FMH_IF_VALID 0 |
| |
| /* fmh_oflags values - returned in the header segment only. */ |
| #define FMH_OF_DEV_T 0x1 /* fmr_device values will be dev_t */ |
| |
| /* fmr_flags values - returned for each non-header segment */ |
| #define FMR_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */ |
| #define FMR_OF_ATTR_FORK 0x2 /* segment = attribute fork */ |
| #define FMR_OF_EXTENT_MAP 0x4 /* segment = extent map */ |
| #define FMR_OF_SHARED 0x8 /* segment = shared with another file */ |
| #define FMR_OF_SPECIAL_OWNER 0x10 /* owner is a special value */ |
| #define FMR_OF_LAST 0x20 /* segment is the last in the dataset */ |
| |
| /* Each FS gets to define its own special owner codes. */ |
| #define FMR_OWNER(type, code) (((__u64)type << 32) | \ |
| ((__u64)code & 0xFFFFFFFFULL)) |
| #define FMR_OWNER_TYPE(owner) ((__u32)((__u64)owner >> 32)) |
| #define FMR_OWNER_CODE(owner) ((__u32)(((__u64)owner & 0xFFFFFFFFULL))) |
| #define FMR_OWN_FREE FMR_OWNER(0, 1) /* free space */ |
| #define FMR_OWN_UNKNOWN FMR_OWNER(0, 2) /* unknown owner */ |
| #define FMR_OWN_METADATA FMR_OWNER(0, 3) /* metadata */ |
| |
| #define FS_IOC_GETFSMAP _IOWR('X', 59, struct fsmap_head) |
| |
| #endif /* _LINUX_FSMAP_H */ |