#ifndef __XFS_ATTR_LEAF_H__
#define __XFS_ATTR_LEAF_H__
-/*
- * Attribute storage layout, internal structure, access macros, etc.
- *
- * 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 attrlist;
struct attrlist_cursor_kern;
struct xfs_attr_list_context;
struct xfs_inode;
struct xfs_trans;
-/*========================================================================
- * Attribute structure when equal to XFS_LBSIZE(mp) bytes.
- *========================================================================*/
-
-/*
- * This is the structure of the leaf nodes in the Btree.
- *
- * 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 */
-
-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 */
- __u8 nameval[1]; /* 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 */
- __u8 name[1]; /* 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[1]; /* sorted on key, not name */
- xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */
- xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */
-} 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[1];
-
- /*
- * 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
- */
-};
-
-/*
- * incore, neutral version of the attribute leaf header
- */
-struct xfs_attr3_icleaf_hdr {
- __uint32_t forw;
- __uint32_t back;
- __uint16_t magic;
- __uint16_t count;
- __uint16_t usedbytes;
- __uint16_t firstused;
- __u8 holes;
- struct {
- __uint16_t base;
- __uint16_t size;
- } freemap[XFS_ATTR_LEAF_MAPSIZE];
-};
-
-/*
- * Flags used in the leaf_entry[i].flags field.
- * NOTE: the INCOMPLETE bit must not collide with the flags bits specified
- * on the system call, they are "or"ed together for various operations.
- */
-#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_INCOMPLETE_BIT 7 /* attr in middle of create/delete */
-#define XFS_ATTR_LOCAL (1 << XFS_ATTR_LOCAL_BIT)
-#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
-#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
-#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
-
-/*
- * Conversion macros for converting namespace bits from argument flags
- * to ondisk flags.
- */
-#define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE)
-#define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
-#define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK)
-#define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK)
-#define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\
- ((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0))
-#define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\
- ((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0))
-
-/*
- * 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)
-{
- return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
- XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
-}
-
-static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
-{
- return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) +
- XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
-}
-
-static inline int xfs_attr_leaf_entsize_local_max(int bsize)
-{
- return (((bsize) >> 1) + ((bsize) >> 2));
-}
-
/*
* Used to keep a list of "remote value" extents when unlinking an inode.
*/
projects / karo-tx-linux.git / blobdiff