linux/fs/xfs/libxfs/xfs_da_format.h
Darrick J. Wong a5714b67ca xfs: turn XFS_ATTR3_RMT_BUF_SPACE into a function
Turn this into a properly typechecked function, and actually use the
correct blocksize for extended attributes.  The function cannot be
static inline because xfsprogs userspace uses it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-05-02 07:48:36 -07:00

908 lines
30 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_DA_FORMAT_H__
#define __XFS_DA_FORMAT_H__
/*
* This structure is common to both leaf nodes and non-leaf nodes in the Btree.
*
* It is used to manage a doubly linked list of all blocks at the same
* level in the Btree, and to identify which type of block this is.
*/
#define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
#define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
#define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
#define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
typedef struct xfs_da_blkinfo {
__be32 forw; /* previous block in list */
__be32 back; /* following block in list */
__be16 magic; /* validity check on block */
__be16 pad; /* unused */
} xfs_da_blkinfo_t;
/*
* CRC enabled directory structure types
*
* The headers change size for the additional verification information, but
* otherwise the tree layouts and contents are unchanged. Hence the da btree
* code can use the struct xfs_da_blkinfo for manipulating the tree links and
* magic numbers without modification for both v2 and v3 nodes.
*/
#define XFS_DA3_NODE_MAGIC 0x3ebe /* magic number: non-leaf blocks */
#define XFS_ATTR3_LEAF_MAGIC 0x3bee /* magic number: attribute leaf blks */
#define XFS_DIR3_LEAF1_MAGIC 0x3df1 /* magic number: v3 dirlf single blks */
#define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v3 dirlf multi blks */
struct xfs_da3_blkinfo {
/*
* the node link manipulation code relies on the fact that the first
* element of this structure is the struct xfs_da_blkinfo so it can
* ignore the differences in the rest of the structures.
*/
struct xfs_da_blkinfo hdr;
__be32 crc; /* CRC of block */
__be64 blkno; /* first block of the buffer */
__be64 lsn; /* sequence number of last write */
uuid_t uuid; /* filesystem we belong to */
__be64 owner; /* inode that owns the block */
};
/*
* This is the structure of the root and intermediate nodes in the Btree.
* The leaf nodes are defined above.
*
* Entries are not packed.
*
* Since we have duplicate keys, use a binary search but always follow
* all match in the block, not just the first match found.
*/
#define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
typedef struct xfs_da_node_hdr {
struct xfs_da_blkinfo info; /* block type, links, etc. */
__be16 __count; /* count of active entries */
__be16 __level; /* level above leaves (leaf == 0) */
} xfs_da_node_hdr_t;
struct xfs_da3_node_hdr {
struct xfs_da3_blkinfo info; /* block type, links, etc. */
__be16 __count; /* count of active entries */
__be16 __level; /* level above leaves (leaf == 0) */
__be32 __pad32;
};
#define XFS_DA3_NODE_CRC_OFF (offsetof(struct xfs_da3_node_hdr, info.crc))
typedef struct xfs_da_node_entry {
__be32 hashval; /* hash value for this descendant */
__be32 before; /* Btree block before this key */
} xfs_da_node_entry_t;
typedef struct xfs_da_intnode {
struct xfs_da_node_hdr hdr;
struct xfs_da_node_entry __btree[];
} xfs_da_intnode_t;
struct xfs_da3_intnode {
struct xfs_da3_node_hdr hdr;
struct xfs_da_node_entry __btree[];
};
/*
* Directory version 2.
*
* There are 4 possible formats:
* - shortform - embedded into the inode
* - single block - data with embedded leaf at the end
* - multiple data blocks, single leaf+freeindex block
* - data blocks, node and leaf blocks (btree), freeindex blocks
*
* Note: many node blocks structures and constants are shared with the attr
* code and defined in xfs_da_btree.h.
*/
#define XFS_DIR2_BLOCK_MAGIC 0x58443242 /* XD2B: single block dirs */
#define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: multiblock dirs */
#define XFS_DIR2_FREE_MAGIC 0x58443246 /* XD2F: free index blocks */
/*
* Directory Version 3 With CRCs.
*
* The tree formats are the same as for version 2 directories. The difference
* is in the block header and dirent formats. In many cases the v3 structures
* use v2 definitions as they are no different and this makes code sharing much
* easier.
*
* Also, the xfs_dir3_*() functions handle both v2 and v3 formats - if the
* format is v2 then they switch to the existing v2 code, or the format is v3
* they implement the v3 functionality. This means the existing dir2 is a mix of
* xfs_dir2/xfs_dir3 calls and functions. The xfs_dir3 functions are called
* where there is a difference in the formats, otherwise the code is unchanged.
*
* Where it is possible, the code decides what to do based on the magic numbers
* in the blocks rather than feature bits in the superblock. This means the code
* is as independent of the external XFS code as possible as doesn't require
* passing struct xfs_mount pointers into places where it isn't really
* necessary.
*
* Version 3 includes:
*
* - a larger block header for CRC and identification purposes and so the
* offsets of all the structures inside the blocks are different.
*
* - new magic numbers to be able to detect the v2/v3 types on the fly.
*/
#define XFS_DIR3_BLOCK_MAGIC 0x58444233 /* XDB3: single block dirs */
#define XFS_DIR3_DATA_MAGIC 0x58444433 /* XDD3: multiblock dirs */
#define XFS_DIR3_FREE_MAGIC 0x58444633 /* XDF3: free index blocks */
/*
* Dirents in version 3 directories have a file type field. Additions to this
* list are an on-disk format change, requiring feature bits. Valid values
* are as follows:
*/
#define XFS_DIR3_FT_UNKNOWN 0
#define XFS_DIR3_FT_REG_FILE 1
#define XFS_DIR3_FT_DIR 2
#define XFS_DIR3_FT_CHRDEV 3
#define XFS_DIR3_FT_BLKDEV 4
#define XFS_DIR3_FT_FIFO 5
#define XFS_DIR3_FT_SOCK 6
#define XFS_DIR3_FT_SYMLINK 7
#define XFS_DIR3_FT_WHT 8
#define XFS_DIR3_FT_MAX 9
#define XFS_DIR3_FTYPE_STR \
{ XFS_DIR3_FT_UNKNOWN, "unknown" }, \
{ XFS_DIR3_FT_REG_FILE, "file" }, \
{ XFS_DIR3_FT_DIR, "directory" }, \
{ XFS_DIR3_FT_CHRDEV, "char" }, \
{ XFS_DIR3_FT_BLKDEV, "block" }, \
{ XFS_DIR3_FT_FIFO, "fifo" }, \
{ XFS_DIR3_FT_SOCK, "sock" }, \
{ XFS_DIR3_FT_SYMLINK, "symlink" }, \
{ XFS_DIR3_FT_WHT, "whiteout" }
/*
* Byte offset in data block and shortform entry.
*/
typedef uint16_t xfs_dir2_data_off_t;
#define NULLDATAOFF 0xffffU
typedef uint xfs_dir2_data_aoff_t; /* argument form */
/*
* Offset in data space of a data entry.
*/
typedef uint32_t xfs_dir2_dataptr_t;
#define XFS_DIR2_MAX_DATAPTR ((xfs_dir2_dataptr_t)0xffffffff)
#define XFS_DIR2_NULL_DATAPTR ((xfs_dir2_dataptr_t)0)
/*
* Byte offset in a directory.
*/
typedef xfs_off_t xfs_dir2_off_t;
/*
* Directory block number (logical dirblk in file)
*/
typedef uint32_t xfs_dir2_db_t;
#define XFS_INO32_SIZE 4
#define XFS_INO64_SIZE 8
#define XFS_INO64_DIFF (XFS_INO64_SIZE - XFS_INO32_SIZE)
#define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
/*
* Directory layout when stored internal to an inode.
*
* Small directories are packed as tightly as possible so as to fit into the
* literal area of the inode. These "shortform" directories consist of a
* single xfs_dir2_sf_hdr header followed by zero or more xfs_dir2_sf_entry
* structures. Due the different inode number storage size and the variable
* length name field in the xfs_dir2_sf_entry all these structure are
* variable length, and the accessors in this file should be used to iterate
* over them.
*/
typedef struct xfs_dir2_sf_hdr {
uint8_t count; /* count of entries */
uint8_t i8count; /* count of 8-byte inode #s */
uint8_t parent[8]; /* parent dir inode number */
} __packed xfs_dir2_sf_hdr_t;
typedef struct xfs_dir2_sf_entry {
__u8 namelen; /* actual name length */
__u8 offset[2]; /* saved offset */
__u8 name[]; /* name, variable size */
/*
* A single byte containing the file type field follows the inode
* number for version 3 directory entries.
*
* A 64-bit or 32-bit inode number follows here, at a variable offset
* after the name.
*/
} __packed xfs_dir2_sf_entry_t;
static inline int xfs_dir2_sf_hdr_size(int i8count)
{
return sizeof(struct xfs_dir2_sf_hdr) -
(i8count == 0) * XFS_INO64_DIFF;
}
static inline xfs_dir2_data_aoff_t
xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
{
return get_unaligned_be16(sfep->offset);
}
static inline void
xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
{
put_unaligned_be16(off, sfep->offset);
}
static inline struct xfs_dir2_sf_entry *
xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr *hdr)
{
return (struct xfs_dir2_sf_entry *)
((char *)hdr + xfs_dir2_sf_hdr_size(hdr->i8count));
}
/*
* Data block structures.
*
* A pure data block looks like the following drawing on disk:
*
* +-------------------------------------------------+
* | xfs_dir2_data_hdr_t |
* +-------------------------------------------------+
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
* | ... |
* +-------------------------------------------------+
* | unused space |
* +-------------------------------------------------+
*
* As all the entries are variable size structures the accessors below should
* be used to iterate over them.
*
* In addition to the pure data blocks for the data and node formats,
* most structures are also used for the combined data/freespace "block"
* format below.
*/
#define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
#define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
#define XFS_DIR2_DATA_FREE_TAG 0xffff
#define XFS_DIR2_DATA_FD_COUNT 3
/*
* Directory address space divided into sections,
* spaces separated by 32GB.
*/
#define XFS_DIR2_MAX_SPACES 3
#define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
#define XFS_DIR2_DATA_SPACE 0
#define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
/*
* Describe a free area in the data block.
*
* The freespace will be formatted as a xfs_dir2_data_unused_t.
*/
typedef struct xfs_dir2_data_free {
__be16 offset; /* start of freespace */
__be16 length; /* length of freespace */
} xfs_dir2_data_free_t;
/*
* Header for the data blocks.
*
* The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
*/
typedef struct xfs_dir2_data_hdr {
__be32 magic; /* XFS_DIR2_DATA_MAGIC or */
/* XFS_DIR2_BLOCK_MAGIC */
xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
} xfs_dir2_data_hdr_t;
/*
* define a structure for all the verification fields we are adding to the
* directory block structures. This will be used in several structures.
* The magic number must be the first entry to align with all the dir2
* structures so we determine how to decode them just by the magic number.
*/
struct xfs_dir3_blk_hdr {
__be32 magic; /* magic number */
__be32 crc; /* CRC of block */
__be64 blkno; /* first block of the buffer */
__be64 lsn; /* sequence number of last write */
uuid_t uuid; /* filesystem we belong to */
__be64 owner; /* inode that owns the block */
};
struct xfs_dir3_data_hdr {
struct xfs_dir3_blk_hdr hdr;
xfs_dir2_data_free_t best_free[XFS_DIR2_DATA_FD_COUNT];
__be32 pad; /* 64 bit alignment */
};
#define XFS_DIR3_DATA_CRC_OFF offsetof(struct xfs_dir3_data_hdr, hdr.crc)
/*
* Active entry in a data block.
*
* Aligned to 8 bytes. After the variable length name field there is a
* 2 byte tag field, which can be accessed using xfs_dir3_data_entry_tag_p.
*
* For dir3 structures, there is file type field between the name and the tag.
* This can only be manipulated by helper functions. It is packed hard against
* the end of the name so any padding for rounding is between the file type and
* the tag.
*/
typedef struct xfs_dir2_data_entry {
__be64 inumber; /* inode number */
__u8 namelen; /* name length */
__u8 name[]; /* name bytes, no null */
/* __u8 filetype; */ /* type of inode we point to */
/* __be16 tag; */ /* starting offset of us */
} xfs_dir2_data_entry_t;
/*
* Unused entry in a data block.
*
* Aligned to 8 bytes. Tag appears as the last 2 bytes and must be accessed
* using xfs_dir2_data_unused_tag_p.
*/
typedef struct xfs_dir2_data_unused {
__be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
__be16 length; /* total free length */
/* variable offset */
__be16 tag; /* starting offset of us */
} xfs_dir2_data_unused_t;
/*
* Pointer to a freespace's tag word.
*/
static inline __be16 *
xfs_dir2_data_unused_tag_p(struct xfs_dir2_data_unused *dup)
{
return (__be16 *)((char *)dup +
be16_to_cpu(dup->length) - sizeof(__be16));
}
/*
* Leaf block structures.
*
* A pure leaf block looks like the following drawing on disk:
*
* +---------------------------+
* | xfs_dir2_leaf_hdr_t |
* +---------------------------+
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | ... |
* +---------------------------+
* | xfs_dir2_data_off_t |
* | xfs_dir2_data_off_t |
* | xfs_dir2_data_off_t |
* | ... |
* +---------------------------+
* | xfs_dir2_leaf_tail_t |
* +---------------------------+
*
* The xfs_dir2_data_off_t members (bests) and tail are at the end of the block
* for single-leaf (magic = XFS_DIR2_LEAF1_MAGIC) blocks only, but not present
* for directories with separate leaf nodes and free space blocks
* (magic = XFS_DIR2_LEAFN_MAGIC).
*
* As all the entries are variable size structures the accessors below should
* be used to iterate over them.
*/
/*
* Offset of the leaf/node space. First block in this space
* is the btree root.
*/
#define XFS_DIR2_LEAF_SPACE 1
#define XFS_DIR2_LEAF_OFFSET (XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE)
/*
* Leaf block header.
*/
typedef struct xfs_dir2_leaf_hdr {
xfs_da_blkinfo_t info; /* header for da routines */
__be16 count; /* count of entries */
__be16 stale; /* count of stale entries */
} xfs_dir2_leaf_hdr_t;
struct xfs_dir3_leaf_hdr {
struct xfs_da3_blkinfo info; /* header for da routines */
__be16 count; /* count of entries */
__be16 stale; /* count of stale entries */
__be32 pad; /* 64 bit alignment */
};
/*
* Leaf block entry.
*/
typedef struct xfs_dir2_leaf_entry {
__be32 hashval; /* hash value of name */
__be32 address; /* address of data entry */
} xfs_dir2_leaf_entry_t;
/*
* Leaf block tail.
*/
typedef struct xfs_dir2_leaf_tail {
__be32 bestcount;
} xfs_dir2_leaf_tail_t;
/*
* Leaf block.
*/
typedef struct xfs_dir2_leaf {
xfs_dir2_leaf_hdr_t hdr; /* leaf header */
xfs_dir2_leaf_entry_t __ents[]; /* entries */
} xfs_dir2_leaf_t;
struct xfs_dir3_leaf {
struct xfs_dir3_leaf_hdr hdr; /* leaf header */
struct xfs_dir2_leaf_entry __ents[]; /* entries */
};
#define XFS_DIR3_LEAF_CRC_OFF offsetof(struct xfs_dir3_leaf_hdr, info.crc)
/*
* Get address of the bests array in the single-leaf block.
*/
static inline __be16 *
xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail *ltp)
{
return (__be16 *)ltp - be32_to_cpu(ltp->bestcount);
}
/*
* Free space block definitions for the node format.
*/
/*
* Offset of the freespace index.
*/
#define XFS_DIR2_FREE_SPACE 2
#define XFS_DIR2_FREE_OFFSET (XFS_DIR2_FREE_SPACE * XFS_DIR2_SPACE_SIZE)
typedef struct xfs_dir2_free_hdr {
__be32 magic; /* XFS_DIR2_FREE_MAGIC */
__be32 firstdb; /* db of first entry */
__be32 nvalid; /* count of valid entries */
__be32 nused; /* count of used entries */
} xfs_dir2_free_hdr_t;
typedef struct xfs_dir2_free {
xfs_dir2_free_hdr_t hdr; /* block header */
__be16 bests[]; /* best free counts */
/* unused entries are -1 */
} xfs_dir2_free_t;
struct xfs_dir3_free_hdr {
struct xfs_dir3_blk_hdr hdr;
__be32 firstdb; /* db of first entry */
__be32 nvalid; /* count of valid entries */
__be32 nused; /* count of used entries */
__be32 pad; /* 64 bit alignment */
};
struct xfs_dir3_free {
struct xfs_dir3_free_hdr hdr;
__be16 bests[]; /* best free counts */
/* unused entries are -1 */
};
#define XFS_DIR3_FREE_CRC_OFF offsetof(struct xfs_dir3_free, hdr.hdr.crc)
/*
* Single block format.
*
* The single block format looks like the following drawing on disk:
*
* +-------------------------------------------------+
* | xfs_dir2_data_hdr_t |
* +-------------------------------------------------+
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
* | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t :
* | ... |
* +-------------------------------------------------+
* | unused space |
* +-------------------------------------------------+
* | ... |
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* +-------------------------------------------------+
* | xfs_dir2_block_tail_t |
* +-------------------------------------------------+
*
* As all the entries are variable size structures the accessors below should
* be used to iterate over them.
*/
typedef struct xfs_dir2_block_tail {
__be32 count; /* count of leaf entries */
__be32 stale; /* count of stale lf entries */
} xfs_dir2_block_tail_t;
/*
* Pointer to the leaf entries embedded in a data block (1-block format)
*/
static inline struct xfs_dir2_leaf_entry *
xfs_dir2_block_leaf_p(struct xfs_dir2_block_tail *btp)
{
return ((struct xfs_dir2_leaf_entry *)btp) - be32_to_cpu(btp->count);
}
/*
* Attribute storage layout
*
* 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.
*
* Struct leaf_entry's are packed from the top. Name/values grow from the
* bottom but are not packed. The freemap contains run-length-encoded entries
* for the free bytes after the leaf_entry's, but only the N largest such,
* smaller runs are dropped. When the freemap doesn't show enough space
* for an allocation, we compact the name/value area and try again. If we
* still don't have enough space, then we have to split the block. The
* name/value structs (both local and remote versions) must be 32bit aligned.
*
* Since we have duplicate hash keys, for each key that matches, compare
* the actual name string. The root and intermediate node search always
* takes the first-in-the-block key match found, so we should only have
* to work "forw"ard. If none matches, continue with the "forw"ard leaf
* nodes until the hash key changes or the attribute name is found.
*
* We store the fact that an attribute is a ROOT/USER/SECURE attribute in
* the leaf_entry. The namespaces are independent only because we also look
* at the namespace bit when we are looking for a matching attribute name.
*
* We also store an "incomplete" bit in the leaf_entry. It shows that an
* attribute is in the middle of being created and should not be shown to
* the user if we crash during the time that the bit is set. We clear the
* bit when we have finished setting up the attribute. We do this because
* we cannot create some large attributes inside a single transaction, and we
* need some indication that we weren't finished if we crash in the middle.
*/
#define XFS_ATTR_LEAF_MAPSIZE 3 /* how many freespace slots */
/*
* Attribute storage when stored inside the inode.
*
* Small attribute lists are packed as tightly as possible so as to fit into the
* literal area of the inode.
*
* These "shortform" attribute forks consist of a single xfs_attr_sf_hdr header
* followed by zero or more xfs_attr_sf_entry structures.
*/
struct xfs_attr_sf_hdr { /* constant-structure header block */
__be16 totsize; /* total bytes in shortform list */
__u8 count; /* count of active entries */
__u8 padding;
};
struct xfs_attr_sf_entry {
__u8 namelen; /* actual length of name (no NULL) */
__u8 valuelen; /* actual length of value (no NULL) */
__u8 flags; /* flags bits (XFS_ATTR_*) */
__u8 nameval[]; /* name & value bytes concatenated */
};
typedef struct xfs_attr_leaf_map { /* RLE map of free bytes */
__be16 base; /* base of free region */
__be16 size; /* length of free region */
} xfs_attr_leaf_map_t;
typedef struct xfs_attr_leaf_hdr { /* constant-structure header block */
xfs_da_blkinfo_t info; /* block type, links, etc. */
__be16 count; /* count of active leaf_entry's */
__be16 usedbytes; /* num bytes of names/values stored */
__be16 firstused; /* first used byte in name area */
__u8 holes; /* != 0 if blk needs compaction */
__u8 pad1;
xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE];
/* N largest free regions */
} xfs_attr_leaf_hdr_t;
typedef struct xfs_attr_leaf_entry { /* sorted on key, not name */
__be32 hashval; /* hash value of name */
__be16 nameidx; /* index into buffer of name/value */
__u8 flags; /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
__u8 pad2; /* unused pad byte */
} xfs_attr_leaf_entry_t;
typedef struct xfs_attr_leaf_name_local {
__be16 valuelen; /* number of bytes in value */
__u8 namelen; /* length of name bytes */
/*
* In Linux 6.5 this flex array was converted from nameval[1] to
* nameval[]. Be very careful here about extra padding at the end;
* see xfs_attr_leaf_entsize_local() for details.
*/
__u8 nameval[]; /* name/value bytes */
} xfs_attr_leaf_name_local_t;
typedef struct xfs_attr_leaf_name_remote {
__be32 valueblk; /* block number of value bytes */
__be32 valuelen; /* number of bytes in value */
__u8 namelen; /* length of name bytes */
/*
* In Linux 6.5 this flex array was converted from name[1] to name[].
* Be very careful here about extra padding at the end; see
* xfs_attr_leaf_entsize_remote() for details.
*/
__u8 name[]; /* name bytes */
} xfs_attr_leaf_name_remote_t;
typedef struct xfs_attr_leafblock {
xfs_attr_leaf_hdr_t hdr; /* constant-structure header block */
xfs_attr_leaf_entry_t entries[]; /* sorted on key, not name */
/*
* The rest of the block contains the following structures after the
* leaf entries, growing from the bottom up. The variables are never
* referenced and definining them can actually make gcc optimize away
* accesses to the 'entries' array above index 0 so don't do that.
*
* xfs_attr_leaf_name_local_t namelist;
* xfs_attr_leaf_name_remote_t valuelist;
*/
} xfs_attr_leafblock_t;
/*
* CRC enabled leaf structures. Called "version 3" structures to match the
* version number of the directory and dablk structures for this feature, and
* attr2 is already taken by the variable inode attribute fork size feature.
*/
struct xfs_attr3_leaf_hdr {
struct xfs_da3_blkinfo info;
__be16 count;
__be16 usedbytes;
__be16 firstused;
__u8 holes;
__u8 pad1;
struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
__be32 pad2; /* 64 bit alignment */
};
#define XFS_ATTR3_LEAF_CRC_OFF (offsetof(struct xfs_attr3_leaf_hdr, info.crc))
struct xfs_attr3_leafblock {
struct xfs_attr3_leaf_hdr hdr;
struct xfs_attr_leaf_entry entries[];
/*
* The rest of the block contains the following structures after the
* leaf entries, growing from the bottom up. The variables are never
* referenced, the locations accessed purely from helper functions.
*
* struct xfs_attr_leaf_name_local
* struct xfs_attr_leaf_name_remote
*/
};
/*
* Special value to represent fs block size in the leaf header firstused field.
* Only used when block size overflows the 2-bytes available on disk.
*/
#define XFS_ATTR3_LEAF_NULLOFF 0
/*
* Flags used in the leaf_entry[i].flags field.
*/
#define XFS_ATTR_LOCAL_BIT 0 /* attr is stored locally */
#define XFS_ATTR_ROOT_BIT 1 /* limit access to trusted attrs */
#define XFS_ATTR_SECURE_BIT 2 /* limit access to secure attrs */
#define XFS_ATTR_PARENT_BIT 3 /* parent pointer attrs */
#define XFS_ATTR_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
#define XFS_ATTR_LOCAL (1u << XFS_ATTR_LOCAL_BIT)
#define XFS_ATTR_ROOT (1u << XFS_ATTR_ROOT_BIT)
#define XFS_ATTR_SECURE (1u << XFS_ATTR_SECURE_BIT)
#define XFS_ATTR_PARENT (1u << XFS_ATTR_PARENT_BIT)
#define XFS_ATTR_INCOMPLETE (1u << XFS_ATTR_INCOMPLETE_BIT)
#define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | \
XFS_ATTR_SECURE | \
XFS_ATTR_PARENT)
/* Private attr namespaces not exposed to userspace */
#define XFS_ATTR_PRIVATE_NSP_MASK (XFS_ATTR_PARENT)
#define XFS_ATTR_ONDISK_MASK (XFS_ATTR_NSP_ONDISK_MASK | \
XFS_ATTR_LOCAL | \
XFS_ATTR_INCOMPLETE)
#define XFS_ATTR_NAMESPACE_STR \
{ XFS_ATTR_LOCAL, "local" }, \
{ XFS_ATTR_ROOT, "root" }, \
{ XFS_ATTR_SECURE, "secure" }, \
{ XFS_ATTR_PARENT, "parent" }
/*
* Alignment for namelist and valuelist entries (since they are mixed
* there can be only one alignment value)
*/
#define XFS_ATTR_LEAF_NAME_ALIGN ((uint)sizeof(xfs_dablk_t))
static inline int
xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
{
if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
return sizeof(struct xfs_attr3_leaf_hdr);
return sizeof(struct xfs_attr_leaf_hdr);
}
static inline struct xfs_attr_leaf_entry *
xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
{
if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
return &leafp->entries[0];
}
/*
* Cast typed pointers for "local" and "remote" name/value structs.
*/
static inline char *
xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
{
struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
}
static inline xfs_attr_leaf_name_remote_t *
xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
{
return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
}
static inline xfs_attr_leaf_name_local_t *
xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
{
return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
}
/*
* Calculate total bytes used (including trailing pad for alignment) for
* a "local" name/value structure, a "remote" name/value structure, and
* a pointer which might be either.
*/
static inline int xfs_attr_leaf_entsize_remote(int nlen)
{
/*
* Prior to Linux 6.5, struct xfs_attr_leaf_name_remote ended with
* name[1], which was used as a flexarray. The layout of this struct
* is 9 bytes of fixed-length fields followed by a __u8 flex array at
* offset 9.
*
* On most architectures, struct xfs_attr_leaf_name_remote had two
* bytes of implicit padding at the end of the struct to make the
* struct length 12. After converting name[1] to name[], there are
* three implicit padding bytes and the struct size remains 12.
* However, there are compiler configurations that do not add implicit
* padding at all (m68k) and have been broken for years.
*
* This entsize computation historically added (the xattr name length)
* to (the padded struct length - 1) and rounded that sum up to the
* nearest multiple of 4 (NAME_ALIGN). IOWs, round_up(11 + nlen, 4).
* This is encoded in the ondisk format, so we cannot change this.
*
* Compute the entsize from offsetof of the flexarray and manually
* adding bytes for the implicit padding.
*/
const size_t remotesize =
offsetof(struct xfs_attr_leaf_name_remote, name) + 2;
return round_up(remotesize + nlen, XFS_ATTR_LEAF_NAME_ALIGN);
}
static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
{
/*
* Prior to Linux 6.5, struct xfs_attr_leaf_name_local ended with
* nameval[1], which was used as a flexarray. The layout of this
* struct is 3 bytes of fixed-length fields followed by a __u8 flex
* array at offset 3.
*
* struct xfs_attr_leaf_name_local had zero bytes of implicit padding
* at the end of the struct to make the struct length 4. On most
* architectures, after converting nameval[1] to nameval[], there is
* one implicit padding byte and the struct size remains 4. However,
* there are compiler configurations that do not add implicit padding
* at all (m68k) and would break.
*
* This entsize computation historically added (the xattr name and
* value length) to (the padded struct length - 1) and rounded that sum
* up to the nearest multiple of 4 (NAME_ALIGN). IOWs, the formula is
* round_up(3 + nlen + vlen, 4). This is encoded in the ondisk format,
* so we cannot change this.
*
* Compute the entsize from offsetof of the flexarray and manually
* adding bytes for the implicit padding.
*/
const size_t localsize =
offsetof(struct xfs_attr_leaf_name_local, nameval);
return round_up(localsize + nlen + vlen, XFS_ATTR_LEAF_NAME_ALIGN);
}
static inline int xfs_attr_leaf_entsize_local_max(int bsize)
{
return (((bsize) >> 1) + ((bsize) >> 2));
}
/*
* Remote attribute block format definition
*
* There is one of these headers per filesystem block in a remote attribute.
* This is done to ensure there is a 1:1 mapping between the attribute value
* length and the number of blocks needed to store the attribute. This makes the
* verification of a buffer a little more complex, but greatly simplifies the
* allocation, reading and writing of these attributes as we don't have to guess
* the number of blocks needed to store the attribute data.
*/
#define XFS_ATTR3_RMT_MAGIC 0x5841524d /* XARM */
struct xfs_attr3_rmt_hdr {
__be32 rm_magic;
__be32 rm_offset;
__be32 rm_bytes;
__be32 rm_crc;
uuid_t rm_uuid;
__be64 rm_owner;
__be64 rm_blkno;
__be64 rm_lsn;
};
#define XFS_ATTR3_RMT_CRC_OFF offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
unsigned int xfs_attr3_rmt_buf_space(struct xfs_mount *mp);
/* Number of bytes in a directory block. */
static inline unsigned int xfs_dir2_dirblock_bytes(struct xfs_sb *sbp)
{
return 1 << (sbp->sb_blocklog + sbp->sb_dirblklog);
}
xfs_failaddr_t xfs_da3_blkinfo_verify(struct xfs_buf *bp,
struct xfs_da3_blkinfo *hdr3);
/*
* Parent pointer attribute format definition
*
* The xattr name contains the dirent name.
* The xattr value encodes the parent inode number and generation to ease
* opening parents by handle.
* The xattr hashval is xfs_dir2_namehash() ^ p_ino
*/
struct xfs_parent_rec {
__be64 p_ino;
__be32 p_gen;
} __packed;
#endif /* __XFS_DA_FORMAT_H__ */