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Diffstat (limited to 'fs/xfs/xfs_attr.h')
-rw-r--r-- | fs/xfs/xfs_attr.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr.h b/fs/xfs/xfs_attr.h new file mode 100644 index 000000000..dd4824589 --- /dev/null +++ b/fs/xfs/xfs_attr.h @@ -0,0 +1,154 @@ +/* + * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_ATTR_H__ +#define __XFS_ATTR_H__ + +struct xfs_inode; +struct xfs_da_args; +struct xfs_attr_list_context; + +/* + * Large attribute lists are structured around Btrees where all the data + * elements are in the leaf nodes. Attribute names are hashed into an int, + * then that int is used as the index into the Btree. Since the hashval + * of an attribute name may not be unique, we may have duplicate keys. + * The internal links in the Btree are logical block offsets into the file. + * + * Small attribute lists use a different format and are packed as tightly + * as possible so as to fit into the literal area of the inode. + */ + +/*======================================================================== + * External interfaces + *========================================================================*/ + + +#define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */ +#define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */ +#define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */ +#define ATTR_SECURE 0x0008 /* use attrs in security namespace */ +#define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */ +#define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */ + +#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */ +#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */ + +#define XFS_ATTR_FLAGS \ + { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \ + { ATTR_ROOT, "ROOT" }, \ + { ATTR_TRUST, "TRUST" }, \ + { ATTR_SECURE, "SECURE" }, \ + { ATTR_CREATE, "CREATE" }, \ + { ATTR_REPLACE, "REPLACE" }, \ + { ATTR_KERNOTIME, "KERNOTIME" }, \ + { ATTR_KERNOVAL, "KERNOVAL" } + +/* + * The maximum size (into the kernel or returned from the kernel) of an + * attribute value or the buffer used for an attr_list() call. Larger + * sizes will result in an ERANGE return code. + */ +#define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */ + +/* + * Define how lists of attribute names are returned to the user from + * the attr_list() call. A large, 32bit aligned, buffer is passed in + * along with its size. We put an array of offsets at the top that each + * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom. + */ +typedef struct attrlist { + __s32 al_count; /* number of entries in attrlist */ + __s32 al_more; /* T/F: more attrs (do call again) */ + __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */ +} attrlist_t; + +/* + * Show the interesting info about one attribute. This is what the + * al_offset[i] entry points to. + */ +typedef struct attrlist_ent { /* data from attr_list() */ + __u32 a_valuelen; /* number bytes in value of attr */ + char a_name[1]; /* attr name (NULL terminated) */ +} attrlist_ent_t; + +/* + * Given a pointer to the (char*) buffer containing the attr_list() result, + * and an index, return a pointer to the indicated attribute in the buffer. + */ +#define ATTR_ENTRY(buffer, index) \ + ((attrlist_ent_t *) \ + &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ]) + +/* + * Kernel-internal version of the attrlist cursor. + */ +typedef struct attrlist_cursor_kern { + __u32 hashval; /* hash value of next entry to add */ + __u32 blkno; /* block containing entry (suggestion) */ + __u32 offset; /* offset in list of equal-hashvals */ + __u16 pad1; /* padding to match user-level */ + __u8 pad2; /* padding to match user-level */ + __u8 initted; /* T/F: cursor has been initialized */ +} attrlist_cursor_kern_t; + + +/*======================================================================== + * Structure used to pass context around among the routines. + *========================================================================*/ + + +typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int, + unsigned char *, int, int, unsigned char *); + +typedef struct xfs_attr_list_context { + struct xfs_inode *dp; /* inode */ + struct attrlist_cursor_kern *cursor; /* position in list */ + char *alist; /* output buffer */ + int seen_enough; /* T/F: seen enough of list? */ + ssize_t count; /* num used entries */ + int dupcnt; /* count dup hashvals seen */ + int bufsize; /* total buffer size */ + int firstu; /* first used byte in buffer */ + int flags; /* from VOP call */ + int resynch; /* T/F: resynch with cursor */ + int put_value; /* T/F: need value for listent */ + put_listent_func_t put_listent; /* list output fmt function */ + int index; /* index into output buffer */ +} xfs_attr_list_context_t; + + +/*======================================================================== + * Function prototypes for the kernel. + *========================================================================*/ + +/* + * Overall external interface routines. + */ +int xfs_attr_inactive(struct xfs_inode *dp); +int xfs_attr_list_int(struct xfs_attr_list_context *); +int xfs_inode_hasattr(struct xfs_inode *ip); +int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name, + unsigned char *value, int *valuelenp, int flags); +int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name, + unsigned char *value, int valuelen, int flags); +int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags); +int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize, + int flags, struct attrlist_cursor_kern *cursor); + + +#endif /* __XFS_ATTR_H__ */ |