LXR linux/fs/xfs/libxfs/xfs

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#ifndef __XFS_ATTR_H__
   7#define __XFS_ATTR_H__
   8
   9struct xfs_inode;
  10struct xfs_da_args;
  11struct xfs_attr_list_context;
  12
  13/*
  14 * Large attribute lists are structured around Btrees where all the data
  15 * elements are in the leaf nodes.  Attribute names are hashed into an int,
  16 * then that int is used as the index into the Btree.  Since the hashval
  17 * of an attribute name may not be unique, we may have duplicate keys.
  18 * The internal links in the Btree are logical block offsets into the file.
  19 *
  20 * Small attribute lists use a different format and are packed as tightly
  21 * as possible so as to fit into the literal area of the inode.
  22 */
  23
  24/*
  25 * The maximum size (into the kernel or returned from the kernel) of an
  26 * attribute value or the buffer used for an attr_list() call.  Larger
  27 * sizes will result in an ERANGE return code.
  28 */
  29#define ATTR_MAX_VALUELEN       (64*1024)       /* max length of a value */
  30
  31/*
  32 * Kernel-internal version of the attrlist cursor.
  33 */
  34struct xfs_attrlist_cursor_kern {
  35        __u32   hashval;        /* hash value of next entry to add */
  36        __u32   blkno;          /* block containing entry (suggestion) */
  37        __u32   offset;         /* offset in list of equal-hashvals */
  38        __u16   pad1;           /* padding to match user-level */
  39        __u8    pad2;           /* padding to match user-level */
  40        __u8    initted;        /* T/F: cursor has been initialized */
  41};
  42
  43
  44/*========================================================================
  45 * Structure used to pass context around among the routines.
  46 *========================================================================*/
  47
  48
  49/* void; state communicated via *context */
  50typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int,
  51                              unsigned char *, int, int);
  52
  53struct xfs_attr_list_context {
  54        struct xfs_trans        *tp;
  55        struct xfs_inode        *dp;            /* inode */
  56        struct xfs_attrlist_cursor_kern cursor; /* position in list */
  57        void                    *buffer;        /* output buffer */
  58
  59        /*
  60         * Abort attribute list iteration if non-zero.  Can be used to pass
  61         * error values to the xfs_attr_list caller.
  62         */
  63        int                     seen_enough;
  64        bool                    allow_incomplete;
  65
  66        ssize_t                 count;          /* num used entries */
  67        int                     dupcnt;         /* count dup hashvals seen */
  68        int                     bufsize;        /* total buffer size */
  69        int                     firstu;         /* first used byte in buffer */
  70        unsigned int            attr_filter;    /* XFS_ATTR_{ROOT,SECURE} */
  71        int                     resynch;        /* T/F: resynch with cursor */
  72        put_listent_func_t      put_listent;    /* list output fmt function */
  73        int                     index;          /* index into output buffer */
  74};
  75
  76
  77/*========================================================================
  78 * Function prototypes for the kernel.
  79 *========================================================================*/
  80
  81/*
  82 * Overall external interface routines.
  83 */
  84int xfs_attr_inactive(struct xfs_inode *dp);
  85int xfs_attr_list_ilocked(struct xfs_attr_list_context *);
  86int xfs_attr_list(struct xfs_attr_list_context *);
  87int xfs_inode_hasattr(struct xfs_inode *ip);
  88int xfs_attr_get_ilocked(struct xfs_da_args *args);
  89int xfs_attr_get(struct xfs_da_args *args);
  90int xfs_attr_set(struct xfs_da_args *args);
  91int xfs_attr_set_args(struct xfs_da_args *args);
  92int xfs_has_attr(struct xfs_da_args *args);
  93int xfs_attr_remove_args(struct xfs_da_args *args);
  94bool xfs_attr_namecheck(const void *name, size_t length);
  95
  96#endif  /* __XFS_ATTR_H__ */
  97