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fs.h (21732B) - Raw


      1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
      2 #ifndef _LINUX_FS_H
      3 #define _LINUX_FS_H
      4 
      5 /*
      6  * This file has definitions for some important file table structures
      7  * and constants and structures used by various generic file system
      8  * ioctl's.  Please do not make any changes in this file before
      9  * sending patches for review to linux-fsdevel@vger.kernel.org and
     10  * linux-api@vger.kernel.org.
     11  */
     12 
     13 #include <linux/limits.h>
     14 #include <linux/ioctl.h>
     15 #include <linux/types.h>
     16 #include <linux/fscrypt.h>
     17 
     18 /* Use of MS_* flags within the kernel is restricted to core mount(2) code. */
     19 #include <linux/mount.h>
     20 
     21 /*
     22  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
     23  * the file limit at runtime and only root can increase the per-process
     24  * nr_file rlimit, so it's safe to set up a ridiculously high absolute
     25  * upper limit on files-per-process.
     26  *
     27  * Some programs (notably those using select()) may have to be 
     28  * recompiled to take full advantage of the new limits..  
     29  */
     30 
     31 /* Fixed constants first: */
     32 #undef NR_OPEN
     33 #define INR_OPEN_CUR 1024	/* Initial setting for nfile rlimits */
     34 #define INR_OPEN_MAX 4096	/* Hard limit for nfile rlimits */
     35 
     36 #define BLOCK_SIZE_BITS 10
     37 #define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
     38 
     39 #define SEEK_SET	0	/* seek relative to beginning of file */
     40 #define SEEK_CUR	1	/* seek relative to current file position */
     41 #define SEEK_END	2	/* seek relative to end of file */
     42 #define SEEK_DATA	3	/* seek to the next data */
     43 #define SEEK_HOLE	4	/* seek to the next hole */
     44 #define SEEK_MAX	SEEK_HOLE
     45 
     46 #define RENAME_NOREPLACE	(1 << 0)	/* Don't overwrite target */
     47 #define RENAME_EXCHANGE		(1 << 1)	/* Exchange source and dest */
     48 #define RENAME_WHITEOUT		(1 << 2)	/* Whiteout source */
     49 
     50 struct file_clone_range {
     51 	__s64 src_fd;
     52 	__u64 src_offset;
     53 	__u64 src_length;
     54 	__u64 dest_offset;
     55 };
     56 
     57 struct fstrim_range {
     58 	__u64 start;
     59 	__u64 len;
     60 	__u64 minlen;
     61 };
     62 
     63 /*
     64  * We include a length field because some filesystems (vfat) have an identifier
     65  * that we do want to expose as a UUID, but doesn't have the standard length.
     66  *
     67  * We use a fixed size buffer beacuse this interface will, by fiat, never
     68  * support "UUIDs" longer than 16 bytes; we don't want to force all downstream
     69  * users to have to deal with that.
     70  */
     71 struct fsuuid2 {
     72 	__u8	len;
     73 	__u8	uuid[16];
     74 };
     75 
     76 struct fs_sysfs_path {
     77 	__u8			len;
     78 	__u8			name[128];
     79 };
     80 
     81 /* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */
     82 #define FILE_DEDUPE_RANGE_SAME		0
     83 #define FILE_DEDUPE_RANGE_DIFFERS	1
     84 
     85 /* from struct btrfs_ioctl_file_extent_same_info */
     86 struct file_dedupe_range_info {
     87 	__s64 dest_fd;		/* in - destination file */
     88 	__u64 dest_offset;	/* in - start of extent in destination */
     89 	__u64 bytes_deduped;	/* out - total # of bytes we were able
     90 				 * to dedupe from this file. */
     91 	/* status of this dedupe operation:
     92 	 * < 0 for error
     93 	 * == FILE_DEDUPE_RANGE_SAME if dedupe succeeds
     94 	 * == FILE_DEDUPE_RANGE_DIFFERS if data differs
     95 	 */
     96 	__s32 status;		/* out - see above description */
     97 	__u32 reserved;		/* must be zero */
     98 };
     99 
    100 /* from struct btrfs_ioctl_file_extent_same_args */
    101 struct file_dedupe_range {
    102 	__u64 src_offset;	/* in - start of extent in source */
    103 	__u64 src_length;	/* in - length of extent */
    104 	__u16 dest_count;	/* in - total elements in info array */
    105 	__u16 reserved1;	/* must be zero */
    106 	__u32 reserved2;	/* must be zero */
    107 	struct file_dedupe_range_info info[];
    108 };
    109 
    110 /* And dynamically-tunable limits and defaults: */
    111 struct files_stat_struct {
    112 	unsigned long nr_files;		/* read only */
    113 	unsigned long nr_free_files;	/* read only */
    114 	unsigned long max_files;		/* tunable */
    115 };
    116 
    117 struct inodes_stat_t {
    118 	long nr_inodes;
    119 	long nr_unused;
    120 	long dummy[5];		/* padding for sysctl ABI compatibility */
    121 };
    122 
    123 
    124 #define NR_FILE  8192	/* this can well be larger on a larger system */
    125 
    126 /*
    127  * Structure for FS_IOC_FSGETXATTR[A] and FS_IOC_FSSETXATTR.
    128  */
    129 struct fsxattr {
    130 	__u32		fsx_xflags;	/* xflags field value (get/set) */
    131 	__u32		fsx_extsize;	/* extsize field value (get/set)*/
    132 	__u32		fsx_nextents;	/* nextents field value (get)	*/
    133 	__u32		fsx_projid;	/* project identifier (get/set) */
    134 	__u32		fsx_cowextsize;	/* CoW extsize field value (get/set)*/
    135 	unsigned char	fsx_pad[8];
    136 };
    137 
    138 /*
    139  * Flags for the fsx_xflags field
    140  */
    141 #define FS_XFLAG_REALTIME	0x00000001	/* data in realtime volume */
    142 #define FS_XFLAG_PREALLOC	0x00000002	/* preallocated file extents */
    143 #define FS_XFLAG_IMMUTABLE	0x00000008	/* file cannot be modified */
    144 #define FS_XFLAG_APPEND		0x00000010	/* all writes append */
    145 #define FS_XFLAG_SYNC		0x00000020	/* all writes synchronous */
    146 #define FS_XFLAG_NOATIME	0x00000040	/* do not update access time */
    147 #define FS_XFLAG_NODUMP		0x00000080	/* do not include in backups */
    148 #define FS_XFLAG_RTINHERIT	0x00000100	/* create with rt bit set */
    149 #define FS_XFLAG_PROJINHERIT	0x00000200	/* create with parents projid */
    150 #define FS_XFLAG_NOSYMLINKS	0x00000400	/* disallow symlink creation */
    151 #define FS_XFLAG_EXTSIZE	0x00000800	/* extent size allocator hint */
    152 #define FS_XFLAG_EXTSZINHERIT	0x00001000	/* inherit inode extent size */
    153 #define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
    154 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
    155 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
    156 #define FS_XFLAG_COWEXTSIZE	0x00010000	/* CoW extent size allocator hint */
    157 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
    158 
    159 /* the read-only stuff doesn't really belong here, but any other place is
    160    probably as bad and I don't want to create yet another include file. */
    161 
    162 #define BLKROSET   _IO(0x12,93)	/* set device read-only (0 = read-write) */
    163 #define BLKROGET   _IO(0x12,94)	/* get read-only status (0 = read_write) */
    164 #define BLKRRPART  _IO(0x12,95)	/* re-read partition table */
    165 #define BLKGETSIZE _IO(0x12,96)	/* return device size /512 (long *arg) */
    166 #define BLKFLSBUF  _IO(0x12,97)	/* flush buffer cache */
    167 #define BLKRASET   _IO(0x12,98)	/* set read ahead for block device */
    168 #define BLKRAGET   _IO(0x12,99)	/* get current read ahead setting */
    169 #define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
    170 #define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
    171 #define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
    172 #define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
    173 #define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
    174 #if 0
    175 #define BLKPG      _IO(0x12,105)/* See blkpg.h */
    176 
    177 /* Some people are morons.  Do not use sizeof! */
    178 
    179 #define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
    180 #define BLKELVSET  _IOW(0x12,107,size_t)/* elevator set */
    181 /* This was here just to show that the number is taken -
    182    probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
    183 #endif
    184 /* A jump here: 108-111 have been used for various private purposes. */
    185 #define BLKBSZGET  _IOR(0x12,112,size_t)
    186 #define BLKBSZSET  _IOW(0x12,113,size_t)
    187 #define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */
    188 #define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
    189 #define BLKTRACESTART _IO(0x12,116)
    190 #define BLKTRACESTOP _IO(0x12,117)
    191 #define BLKTRACETEARDOWN _IO(0x12,118)
    192 #define BLKDISCARD _IO(0x12,119)
    193 #define BLKIOMIN _IO(0x12,120)
    194 #define BLKIOOPT _IO(0x12,121)
    195 #define BLKALIGNOFF _IO(0x12,122)
    196 #define BLKPBSZGET _IO(0x12,123)
    197 #define BLKDISCARDZEROES _IO(0x12,124)
    198 #define BLKSECDISCARD _IO(0x12,125)
    199 #define BLKROTATIONAL _IO(0x12,126)
    200 #define BLKZEROOUT _IO(0x12,127)
    201 #define BLKGETDISKSEQ _IOR(0x12,128,__u64)
    202 /*
    203  * A jump here: 130-136 are reserved for zoned block devices
    204  * (see uapi/linux/blkzoned.h)
    205  */
    206 
    207 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
    208 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
    209 #define FIGETBSZ   _IO(0x00,2)	/* get the block size used for bmap */
    210 #define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
    211 #define FITHAW		_IOWR('X', 120, int)	/* Thaw */
    212 #define FITRIM		_IOWR('X', 121, struct fstrim_range)	/* Trim */
    213 #define FICLONE		_IOW(0x94, 9, int)
    214 #define FICLONERANGE	_IOW(0x94, 13, struct file_clone_range)
    215 #define FIDEDUPERANGE	_IOWR(0x94, 54, struct file_dedupe_range)
    216 
    217 #define FSLABEL_MAX 256	/* Max chars for the interface; each fs may differ */
    218 
    219 #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
    220 #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
    221 #define	FS_IOC_GETVERSION		_IOR('v', 1, long)
    222 #define	FS_IOC_SETVERSION		_IOW('v', 2, long)
    223 #define FS_IOC_FIEMAP			_IOWR('f', 11, struct fiemap)
    224 #define FS_IOC32_GETFLAGS		_IOR('f', 1, int)
    225 #define FS_IOC32_SETFLAGS		_IOW('f', 2, int)
    226 #define FS_IOC32_GETVERSION		_IOR('v', 1, int)
    227 #define FS_IOC32_SETVERSION		_IOW('v', 2, int)
    228 #define FS_IOC_FSGETXATTR		_IOR('X', 31, struct fsxattr)
    229 #define FS_IOC_FSSETXATTR		_IOW('X', 32, struct fsxattr)
    230 #define FS_IOC_GETFSLABEL		_IOR(0x94, 49, char[FSLABEL_MAX])
    231 #define FS_IOC_SETFSLABEL		_IOW(0x94, 50, char[FSLABEL_MAX])
    232 /* Returns the external filesystem UUID, the same one blkid returns */
    233 #define FS_IOC_GETFSUUID		_IOR(0x15, 0, struct fsuuid2)
    234 /*
    235  * Returns the path component under /sys/fs/ that refers to this filesystem;
    236  * also /sys/kernel/debug/ for filesystems with debugfs exports
    237  */
    238 #define FS_IOC_GETFSSYSFSPATH		_IOR(0x15, 1, struct fs_sysfs_path)
    239 
    240 /*
    241  * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
    242  *
    243  * Note: for historical reasons, these flags were originally used and
    244  * defined for use by ext2/ext3, and then other file systems started
    245  * using these flags so they wouldn't need to write their own version
    246  * of chattr/lsattr (which was shipped as part of e2fsprogs).  You
    247  * should think twice before trying to use these flags in new
    248  * contexts, or trying to assign these flags, since they are used both
    249  * as the UAPI and the on-disk encoding for ext2/3/4.  Also, we are
    250  * almost out of 32-bit flags.  :-)
    251  *
    252  * We have recently hoisted FS_IOC_FSGETXATTR / FS_IOC_FSSETXATTR from
    253  * XFS to the generic FS level interface.  This uses a structure that
    254  * has padding and hence has more room to grow, so it may be more
    255  * appropriate for many new use cases.
    256  *
    257  * Please do not change these flags or interfaces before checking with
    258  * linux-fsdevel@vger.kernel.org and linux-api@vger.kernel.org.
    259  */
    260 #define	FS_SECRM_FL			0x00000001 /* Secure deletion */
    261 #define	FS_UNRM_FL			0x00000002 /* Undelete */
    262 #define	FS_COMPR_FL			0x00000004 /* Compress file */
    263 #define FS_SYNC_FL			0x00000008 /* Synchronous updates */
    264 #define FS_IMMUTABLE_FL			0x00000010 /* Immutable file */
    265 #define FS_APPEND_FL			0x00000020 /* writes to file may only append */
    266 #define FS_NODUMP_FL			0x00000040 /* do not dump file */
    267 #define FS_NOATIME_FL			0x00000080 /* do not update atime */
    268 /* Reserved for compression usage... */
    269 #define FS_DIRTY_FL			0x00000100
    270 #define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
    271 #define FS_NOCOMP_FL			0x00000400 /* Don't compress */
    272 /* End compression flags --- maybe not all used */
    273 #define FS_ENCRYPT_FL			0x00000800 /* Encrypted file */
    274 #define FS_BTREE_FL			0x00001000 /* btree format dir */
    275 #define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
    276 #define FS_IMAGIC_FL			0x00002000 /* AFS directory */
    277 #define FS_JOURNAL_DATA_FL		0x00004000 /* Reserved for ext3 */
    278 #define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
    279 #define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
    280 #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
    281 #define FS_HUGE_FILE_FL			0x00040000 /* Reserved for ext4 */
    282 #define FS_EXTENT_FL			0x00080000 /* Extents */
    283 #define FS_VERITY_FL			0x00100000 /* Verity protected inode */
    284 #define FS_EA_INODE_FL			0x00200000 /* Inode used for large EA */
    285 #define FS_EOFBLOCKS_FL			0x00400000 /* Reserved for ext4 */
    286 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
    287 #define FS_DAX_FL			0x02000000 /* Inode is DAX */
    288 #define FS_INLINE_DATA_FL		0x10000000 /* Reserved for ext4 */
    289 #define FS_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
    290 #define FS_CASEFOLD_FL			0x40000000 /* Folder is case insensitive */
    291 #define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */
    292 
    293 #define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
    294 #define FS_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */
    295 
    296 
    297 #define SYNC_FILE_RANGE_WAIT_BEFORE	1
    298 #define SYNC_FILE_RANGE_WRITE		2
    299 #define SYNC_FILE_RANGE_WAIT_AFTER	4
    300 #define SYNC_FILE_RANGE_WRITE_AND_WAIT	(SYNC_FILE_RANGE_WRITE | \
    301 					 SYNC_FILE_RANGE_WAIT_BEFORE | \
    302 					 SYNC_FILE_RANGE_WAIT_AFTER)
    303 
    304 /*
    305  * Flags for preadv2/pwritev2:
    306  */
    307 
    308 typedef int __bitwise __kernel_rwf_t;
    309 
    310 /* high priority request, poll if possible */
    311 #define RWF_HIPRI	((__kernel_rwf_t)0x00000001)
    312 
    313 /* per-IO O_DSYNC */
    314 #define RWF_DSYNC	((__kernel_rwf_t)0x00000002)
    315 
    316 /* per-IO O_SYNC */
    317 #define RWF_SYNC	((__kernel_rwf_t)0x00000004)
    318 
    319 /* per-IO, return -EAGAIN if operation would block */
    320 #define RWF_NOWAIT	((__kernel_rwf_t)0x00000008)
    321 
    322 /* per-IO O_APPEND */
    323 #define RWF_APPEND	((__kernel_rwf_t)0x00000010)
    324 
    325 /* per-IO negation of O_APPEND */
    326 #define RWF_NOAPPEND	((__kernel_rwf_t)0x00000020)
    327 
    328 /* Atomic Write */
    329 #define RWF_ATOMIC	((__kernel_rwf_t)0x00000040)
    330 
    331 /* mask of flags supported by the kernel */
    332 #define RWF_SUPPORTED	(RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\
    333 			 RWF_APPEND | RWF_NOAPPEND | RWF_ATOMIC)
    334 
    335 #define PROCFS_IOCTL_MAGIC 'f'
    336 
    337 /* Pagemap ioctl */
    338 #define PAGEMAP_SCAN	_IOWR(PROCFS_IOCTL_MAGIC, 16, struct pm_scan_arg)
    339 
    340 /* Bitmasks provided in pm_scan_args masks and reported in page_region.categories. */
    341 #define PAGE_IS_WPALLOWED	(1 << 0)
    342 #define PAGE_IS_WRITTEN		(1 << 1)
    343 #define PAGE_IS_FILE		(1 << 2)
    344 #define PAGE_IS_PRESENT		(1 << 3)
    345 #define PAGE_IS_SWAPPED		(1 << 4)
    346 #define PAGE_IS_PFNZERO		(1 << 5)
    347 #define PAGE_IS_HUGE		(1 << 6)
    348 #define PAGE_IS_SOFT_DIRTY	(1 << 7)
    349 
    350 /*
    351  * struct page_region - Page region with flags
    352  * @start:	Start of the region
    353  * @end:	End of the region (exclusive)
    354  * @categories:	PAGE_IS_* category bitmask for the region
    355  */
    356 struct page_region {
    357 	__u64 start;
    358 	__u64 end;
    359 	__u64 categories;
    360 };
    361 
    362 /* Flags for PAGEMAP_SCAN ioctl */
    363 #define PM_SCAN_WP_MATCHING	(1 << 0)	/* Write protect the pages matched. */
    364 #define PM_SCAN_CHECK_WPASYNC	(1 << 1)	/* Abort the scan when a non-WP-enabled page is found. */
    365 
    366 /*
    367  * struct pm_scan_arg - Pagemap ioctl argument
    368  * @size:		Size of the structure
    369  * @flags:		Flags for the IOCTL
    370  * @start:		Starting address of the region
    371  * @end:		Ending address of the region
    372  * @walk_end		Address where the scan stopped (written by kernel).
    373  *			walk_end == end (address tags cleared) informs that the scan completed on entire range.
    374  * @vec:		Address of page_region struct array for output
    375  * @vec_len:		Length of the page_region struct array
    376  * @max_pages:		Optional limit for number of returned pages (0 = disabled)
    377  * @category_inverted:	PAGE_IS_* categories which values match if 0 instead of 1
    378  * @category_mask:	Skip pages for which any category doesn't match
    379  * @category_anyof_mask: Skip pages for which no category matches
    380  * @return_mask:	PAGE_IS_* categories that are to be reported in `page_region`s returned
    381  */
    382 struct pm_scan_arg {
    383 	__u64 size;
    384 	__u64 flags;
    385 	__u64 start;
    386 	__u64 end;
    387 	__u64 walk_end;
    388 	__u64 vec;
    389 	__u64 vec_len;
    390 	__u64 max_pages;
    391 	__u64 category_inverted;
    392 	__u64 category_mask;
    393 	__u64 category_anyof_mask;
    394 	__u64 return_mask;
    395 };
    396 
    397 /* /proc/<pid>/maps ioctl */
    398 #define PROCMAP_QUERY	_IOWR(PROCFS_IOCTL_MAGIC, 17, struct procmap_query)
    399 
    400 enum procmap_query_flags {
    401 	/*
    402 	 * VMA permission flags.
    403 	 *
    404 	 * Can be used as part of procmap_query.query_flags field to look up
    405 	 * only VMAs satisfying specified subset of permissions. E.g., specifying
    406 	 * PROCMAP_QUERY_VMA_READABLE only will return both readable and read/write VMAs,
    407 	 * while having PROCMAP_QUERY_VMA_READABLE | PROCMAP_QUERY_VMA_WRITABLE will only
    408 	 * return read/write VMAs, though both executable/non-executable and
    409 	 * private/shared will be ignored.
    410 	 *
    411 	 * PROCMAP_QUERY_VMA_* flags are also returned in procmap_query.vma_flags
    412 	 * field to specify actual VMA permissions.
    413 	 */
    414 	PROCMAP_QUERY_VMA_READABLE		= 0x01,
    415 	PROCMAP_QUERY_VMA_WRITABLE		= 0x02,
    416 	PROCMAP_QUERY_VMA_EXECUTABLE		= 0x04,
    417 	PROCMAP_QUERY_VMA_SHARED		= 0x08,
    418 	/*
    419 	 * Query modifier flags.
    420 	 *
    421 	 * By default VMA that covers provided address is returned, or -ENOENT
    422 	 * is returned. With PROCMAP_QUERY_COVERING_OR_NEXT_VMA flag set, closest
    423 	 * VMA with vma_start > addr will be returned if no covering VMA is
    424 	 * found.
    425 	 *
    426 	 * PROCMAP_QUERY_FILE_BACKED_VMA instructs query to consider only VMAs that
    427 	 * have file backing. Can be combined with PROCMAP_QUERY_COVERING_OR_NEXT_VMA
    428 	 * to iterate all VMAs with file backing.
    429 	 */
    430 	PROCMAP_QUERY_COVERING_OR_NEXT_VMA	= 0x10,
    431 	PROCMAP_QUERY_FILE_BACKED_VMA		= 0x20,
    432 };
    433 
    434 /*
    435  * Input/output argument structured passed into ioctl() call. It can be used
    436  * to query a set of VMAs (Virtual Memory Areas) of a process.
    437  *
    438  * Each field can be one of three kinds, marked in a short comment to the
    439  * right of the field:
    440  *   - "in", input argument, user has to provide this value, kernel doesn't modify it;
    441  *   - "out", output argument, kernel sets this field with VMA data;
    442  *   - "in/out", input and output argument; user provides initial value (used
    443  *     to specify maximum allowable buffer size), and kernel sets it to actual
    444  *     amount of data written (or zero, if there is no data).
    445  *
    446  * If matching VMA is found (according to criterias specified by
    447  * query_addr/query_flags, all the out fields are filled out, and ioctl()
    448  * returns 0. If there is no matching VMA, -ENOENT will be returned.
    449  * In case of any other error, negative error code other than -ENOENT is
    450  * returned.
    451  *
    452  * Most of the data is similar to the one returned as text in /proc/<pid>/maps
    453  * file, but procmap_query provides more querying flexibility. There are no
    454  * consistency guarantees between subsequent ioctl() calls, but data returned
    455  * for matched VMA is self-consistent.
    456  */
    457 struct procmap_query {
    458 	/* Query struct size, for backwards/forward compatibility */
    459 	__u64 size;
    460 	/*
    461 	 * Query flags, a combination of enum procmap_query_flags values.
    462 	 * Defines query filtering and behavior, see enum procmap_query_flags.
    463 	 *
    464 	 * Input argument, provided by user. Kernel doesn't modify it.
    465 	 */
    466 	__u64 query_flags;		/* in */
    467 	/*
    468 	 * Query address. By default, VMA that covers this address will
    469 	 * be looked up. PROCMAP_QUERY_* flags above modify this default
    470 	 * behavior further.
    471 	 *
    472 	 * Input argument, provided by user. Kernel doesn't modify it.
    473 	 */
    474 	__u64 query_addr;		/* in */
    475 	/* VMA starting (inclusive) and ending (exclusive) address, if VMA is found. */
    476 	__u64 vma_start;		/* out */
    477 	__u64 vma_end;			/* out */
    478 	/* VMA permissions flags. A combination of PROCMAP_QUERY_VMA_* flags. */
    479 	__u64 vma_flags;		/* out */
    480 	/* VMA backing page size granularity. */
    481 	__u64 vma_page_size;		/* out */
    482 	/*
    483 	 * VMA file offset. If VMA has file backing, this specifies offset
    484 	 * within the file that VMA's start address corresponds to.
    485 	 * Is set to zero if VMA has no backing file.
    486 	 */
    487 	__u64 vma_offset;		/* out */
    488 	/* Backing file's inode number, or zero, if VMA has no backing file. */
    489 	__u64 inode;			/* out */
    490 	/* Backing file's device major/minor number, or zero, if VMA has no backing file. */
    491 	__u32 dev_major;		/* out */
    492 	__u32 dev_minor;		/* out */
    493 	/*
    494 	 * If set to non-zero value, signals the request to return VMA name
    495 	 * (i.e., VMA's backing file's absolute path, with " (deleted)" suffix
    496 	 * appended, if file was unlinked from FS) for matched VMA. VMA name
    497 	 * can also be some special name (e.g., "[heap]", "[stack]") or could
    498 	 * be even user-supplied with prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME).
    499 	 *
    500 	 * Kernel will set this field to zero, if VMA has no associated name.
    501 	 * Otherwise kernel will return actual amount of bytes filled in
    502 	 * user-supplied buffer (see vma_name_addr field below), including the
    503 	 * terminating zero.
    504 	 *
    505 	 * If VMA name is longer that user-supplied maximum buffer size,
    506 	 * -E2BIG error is returned.
    507 	 *
    508 	 * If this field is set to non-zero value, vma_name_addr should point
    509 	 * to valid user space memory buffer of at least vma_name_size bytes.
    510 	 * If set to zero, vma_name_addr should be set to zero as well
    511 	 */
    512 	__u32 vma_name_size;		/* in/out */
    513 	/*
    514 	 * If set to non-zero value, signals the request to extract and return
    515 	 * VMA's backing file's build ID, if the backing file is an ELF file
    516 	 * and it contains embedded build ID.
    517 	 *
    518 	 * Kernel will set this field to zero, if VMA has no backing file,
    519 	 * backing file is not an ELF file, or ELF file has no build ID
    520 	 * embedded.
    521 	 *
    522 	 * Build ID is a binary value (not a string). Kernel will set
    523 	 * build_id_size field to exact number of bytes used for build ID.
    524 	 * If build ID is requested and present, but needs more bytes than
    525 	 * user-supplied maximum buffer size (see build_id_addr field below),
    526 	 * -E2BIG error will be returned.
    527 	 *
    528 	 * If this field is set to non-zero value, build_id_addr should point
    529 	 * to valid user space memory buffer of at least build_id_size bytes.
    530 	 * If set to zero, build_id_addr should be set to zero as well
    531 	 */
    532 	__u32 build_id_size;		/* in/out */
    533 	/*
    534 	 * User-supplied address of a buffer of at least vma_name_size bytes
    535 	 * for kernel to fill with matched VMA's name (see vma_name_size field
    536 	 * description above for details).
    537 	 *
    538 	 * Should be set to zero if VMA name should not be returned.
    539 	 */
    540 	__u64 vma_name_addr;		/* in */
    541 	/*
    542 	 * User-supplied address of a buffer of at least build_id_size bytes
    543 	 * for kernel to fill with matched VMA's ELF build ID, if available
    544 	 * (see build_id_size field description above for details).
    545 	 *
    546 	 * Should be set to zero if build ID should not be returned.
    547 	 */
    548 	__u64 build_id_addr;		/* in */
    549 };
    550 
    551 #endif /* _LINUX_FS_H */