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94dfc73e7c
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].
This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)
@@
identifier S, member, array;
type T1, T2;
@@
struct S {
...
T1 member;
T2 array[
- 0
];
};
-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:
../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
strcpy(de3->name, ".");
^
Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
71 lines
2.7 KiB
C
71 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/*
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* FS_IOC_FIEMAP ioctl infrastructure.
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*
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* Some portions copyright (C) 2007 Cluster File Systems, Inc
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*
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* Authors: Mark Fasheh <mfasheh@suse.com>
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* Kalpak Shah <kalpak.shah@sun.com>
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* Andreas Dilger <adilger@sun.com>
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*/
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#ifndef _UAPI_LINUX_FIEMAP_H
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#define _UAPI_LINUX_FIEMAP_H
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#include <linux/types.h>
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struct fiemap_extent {
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__u64 fe_logical; /* logical offset in bytes for the start of
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* the extent from the beginning of the file */
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__u64 fe_physical; /* physical offset in bytes for the start
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* of the extent from the beginning of the disk */
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__u64 fe_length; /* length in bytes for this extent */
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__u64 fe_reserved64[2];
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__u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
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__u32 fe_reserved[3];
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};
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struct fiemap {
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__u64 fm_start; /* logical offset (inclusive) at
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* which to start mapping (in) */
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__u64 fm_length; /* logical length of mapping which
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* userspace wants (in) */
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__u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
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__u32 fm_mapped_extents;/* number of extents that were mapped (out) */
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__u32 fm_extent_count; /* size of fm_extents array (in) */
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__u32 fm_reserved;
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struct fiemap_extent fm_extents[]; /* array of mapped extents (out) */
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};
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#define FIEMAP_MAX_OFFSET (~0ULL)
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#define FIEMAP_FLAG_SYNC 0x00000001 /* sync file data before map */
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#define FIEMAP_FLAG_XATTR 0x00000002 /* map extended attribute tree */
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#define FIEMAP_FLAG_CACHE 0x00000004 /* request caching of the extents */
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#define FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
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#define FIEMAP_EXTENT_LAST 0x00000001 /* Last extent in file. */
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#define FIEMAP_EXTENT_UNKNOWN 0x00000002 /* Data location unknown. */
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#define FIEMAP_EXTENT_DELALLOC 0x00000004 /* Location still pending.
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* Sets EXTENT_UNKNOWN. */
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#define FIEMAP_EXTENT_ENCODED 0x00000008 /* Data can not be read
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* while fs is unmounted */
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#define FIEMAP_EXTENT_DATA_ENCRYPTED 0x00000080 /* Data is encrypted by fs.
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* Sets EXTENT_NO_BYPASS. */
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#define FIEMAP_EXTENT_NOT_ALIGNED 0x00000100 /* Extent offsets may not be
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* block aligned. */
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#define FIEMAP_EXTENT_DATA_INLINE 0x00000200 /* Data mixed with metadata.
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* Sets EXTENT_NOT_ALIGNED.*/
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#define FIEMAP_EXTENT_DATA_TAIL 0x00000400 /* Multiple files in block.
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* Sets EXTENT_NOT_ALIGNED.*/
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#define FIEMAP_EXTENT_UNWRITTEN 0x00000800 /* Space allocated, but
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* no data (i.e. zero). */
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#define FIEMAP_EXTENT_MERGED 0x00001000 /* File does not natively
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* support extents. Result
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* merged for efficiency. */
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#define FIEMAP_EXTENT_SHARED 0x00002000 /* Space shared with other
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* files. */
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#endif /* _UAPI_LINUX_FIEMAP_H */
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