Exemplo n.º 1
0
/*
 * Look up an entry in the block.  This is the external routine,
 * xfs_dir2_block_lookup_int does the real work.
 */
int						/* error */
xfs_dir2_block_lookup(
	xfs_da_args_t		*args)		/* dir lookup arguments */
{
	xfs_dir2_block_t	*block;		/* block structure */
	xfs_dir2_leaf_entry_t	*blp;		/* block leaf entries */
	xfs_dabuf_t		*bp;		/* block buffer */
	xfs_dir2_block_tail_t	*btp;		/* block tail */
	xfs_dir2_data_entry_t	*dep;		/* block data entry */
	xfs_inode_t		*dp;		/* incore inode */
	int			ent;		/* entry index */
	int			error;		/* error return value */
	xfs_mount_t		*mp;		/* filesystem mount point */

	trace_xfs_dir2_block_lookup(args);

	/*
	 * Get the buffer, look up the entry.
	 * If not found (ENOENT) then return, have no buffer.
	 */
	if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent)))
		return error;
	dp = args->dp;
	mp = dp->i_mount;
	block = bp->data;
	xfs_dir2_data_check(dp, bp);
	btp = xfs_dir2_block_tail_p(mp, block);
	blp = xfs_dir2_block_leaf_p(btp);
	/*
	 * Get the offset from the leaf entry, to point to the data.
	 */
	dep = (xfs_dir2_data_entry_t *)((char *)block +
		xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
	/*
	 * Fill in inode number, CI name if appropriate, release the block.
	 */
	args->inumber = be64_to_cpu(dep->inumber);
	error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
	xfs_da_brelse(args->trans, bp);
	return XFS_ERROR(error);
}
Exemplo n.º 2
0
STATIC int
xfs_dir_node_getdents(xfs_trans_t *trans, xfs_inode_t *dp, uio_t *uio,
			int *eofp, dirent_t *dbp, xfs_dir_put_t put)
{
	xfs_da_intnode_t *node;
	xfs_da_node_entry_t *btree;
	xfs_dir_leafblock_t *leaf;
	xfs_dablk_t bno, nextbno;
	xfs_dahash_t cookhash;
	xfs_mount_t *mp;
	int error, eob, i;
	xfs_dabuf_t *bp;
    xfs_daddr_t nextda;

	/*
	 * Pick up our context.
	 */
	mp = dp->i_mount;
	bp = NULL;
	bno = XFS_DA_COOKIE_BNO(mp, uio->uio_offset);
	cookhash = XFS_DA_COOKIE_HASH(mp, uio->uio_offset);

	xfs_dir_trace_g_du("node: start", dp, uio);

	/*
	 * Re-find our place, even if we're confused about what our place is.
	 *
	 * First we check the block number from the magic cookie, it is a
	 * cache of where we ended last time.  If we find a leaf block, and
	 * the starting hashval in that block is less than our desired
	 * hashval, then we run with it.
	 */
	if (bno > 0) {
		error = xfs_da_read_buf(trans, dp, bno, -1, &bp, XFS_DATA_FORK);
		if ((error != 0) && (error != EFSCORRUPTED))
			return(error);
		if (bp)
			leaf = bp->data;
		if (bp && INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) != XFS_DIR_LEAF_MAGIC) {
			xfs_dir_trace_g_dub("node: block not a leaf",
						   dp, uio, bno);
			xfs_da_brelse(trans, bp);
			bp = NULL;
		}
		if (bp && INT_GET(leaf->entries[0].hashval, ARCH_CONVERT) > cookhash) {
			xfs_dir_trace_g_dub("node: leaf hash too large",
						   dp, uio, bno);
			xfs_da_brelse(trans, bp);
			bp = NULL;
		}
		if (bp &&
		    cookhash > INT_GET(leaf->entries[INT_GET(leaf->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT)) {
			xfs_dir_trace_g_dub("node: leaf hash too small",
						   dp, uio, bno);
			xfs_da_brelse(trans, bp);
			bp = NULL;
		}
	}

	/*
	 * If we did not find a leaf block from the blockno in the cookie,
	 * or we there was no blockno in the cookie (eg: first time thru),
	 * the we start at the top of the Btree and re-find our hashval.
	 */
	if (bp == NULL) {
		xfs_dir_trace_g_du("node: start at root" , dp, uio);
		bno = 0;
		for (;;) {
			error = xfs_da_read_buf(trans, dp, bno, -1, &bp,
						       XFS_DATA_FORK);
			if (error)
				return(error);
			if (bp == NULL)
				return(XFS_ERROR(EFSCORRUPTED));
			node = bp->data;
			if (INT_GET(node->hdr.info.magic, ARCH_CONVERT) != XFS_DA_NODE_MAGIC)
				break;
			btree = &node->btree[0];
			xfs_dir_trace_g_dun("node: node detail", dp, uio, node);
			for (i = 0; i < INT_GET(node->hdr.count, ARCH_CONVERT); btree++, i++) {
				if (INT_GET(btree->hashval, ARCH_CONVERT) >= cookhash) {
					bno = INT_GET(btree->before, ARCH_CONVERT);
					break;
				}
			}
			if (i == INT_GET(node->hdr.count, ARCH_CONVERT)) {
				xfs_da_brelse(trans, bp);
				xfs_dir_trace_g_du("node: hash beyond EOF",
							  dp, uio);
				uio->uio_offset = XFS_DA_MAKE_COOKIE(mp, 0, 0,
							     XFS_DA_MAXHASH);
				*eofp = 1;
				return(0);
			}
			xfs_dir_trace_g_dub("node: going to block",
						   dp, uio, bno);
			xfs_da_brelse(trans, bp);
		}
	}
	ASSERT(cookhash != XFS_DA_MAXHASH);

	/*
	 * We've dropped down to the (first) leaf block that contains the
	 * hashval we are interested in.  Continue rolling upward thru the
	 * leaf blocks until we fill up our buffer.
	 */
	for (;;) {
		leaf = bp->data;
		if (INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) != XFS_DIR_LEAF_MAGIC) {
			xfs_dir_trace_g_dul("node: not a leaf", dp, uio, leaf);
			xfs_da_brelse(trans, bp);
			return XFS_ERROR(EFSCORRUPTED);
		}
		xfs_dir_trace_g_dul("node: leaf detail", dp, uio, leaf);
		if (nextbno = INT_GET(leaf->hdr.info.forw, ARCH_CONVERT)) {
			nextda = xfs_da_reada_buf(trans, dp, nextbno,
						  XFS_DATA_FORK);
		} else
			nextda = -1;
		error = xfs_dir_leaf_getdents_int(bp, dp, bno, uio, &eob, dbp,
						  put, nextda);
		xfs_da_brelse(trans, bp);
		bno = nextbno;
		if (eob) {
			xfs_dir_trace_g_dub("node: E-O-B", dp, uio, bno);
			*eofp = 0;
			return(error);
		}
		if (bno == 0)
			break;
		error = xfs_da_read_buf(trans, dp, bno, nextda, &bp,
					XFS_DATA_FORK);
		if (error)
			return(error);
		if (bp == NULL)
			return(XFS_ERROR(EFSCORRUPTED));
	}
	*eofp = 1;
	xfs_dir_trace_g_du("node: E-O-F", dp, uio);
	return(0);
}
Exemplo n.º 3
0
/*
 * Readdir for block directories.
 */
int						/* error */
xfs_dir2_block_getdents(
                        xfs_inode_t		*dp,		/* incore inode */
                        void			*dirent,
                        xfs_off_t		*offset,
                        filldir_t		filldir)
{
	xfs_dir2_block_t	*block;		/* directory block structure */
	xfs_dabuf_t		*bp;		/* buffer for block */
	xfs_dir2_block_tail_t	*btp;		/* block tail */
	xfs_dir2_data_entry_t	*dep;		/* block data entry */
	xfs_dir2_data_unused_t	*dup;		/* block unused entry */
	char			*endptr;	/* end of the data entries */
	int			error;		/* error return value */
	xfs_mount_t		*mp;		/* filesystem mount point */
	char			*ptr;		/* current data entry */
	int			wantoff;	/* starting block offset */
	xfs_off_t		cook;
    
	mp = dp->i_mount;
	/*
	 * If the block number in the offset is out of range, we're done.
	 */
	if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk) {
		return 0;
	}
	/*
	 * Can't read the block, give up, else get dabuf in bp.
	 */
	error = xfs_da_read_buf(NULL, dp, mp->m_dirdatablk, -1,
                            &bp, XFS_DATA_FORK);
	if (error)
		return error;
    
	ASSERT(bp != NULL);
	/*
	 * Extract the byte offset we start at from the seek pointer.
	 * We'll skip entries before this.
	 */
	wantoff = xfs_dir2_dataptr_to_off(mp, *offset);
	block = bp->data;
	xfs_dir2_data_check(dp, bp);
	/*
	 * Set up values for the loop.
	 */
	btp = xfs_dir2_block_tail_p(mp, block);
	ptr = (char *)block->u;
	endptr = (char *)xfs_dir2_block_leaf_p(btp);
    
	/*
	 * Loop over the data portion of the block.
	 * Each object is a real entry (dep) or an unused one (dup).
	 */
	while (ptr < endptr) {
		dup = (xfs_dir2_data_unused_t *)ptr;
		/*
		 * Unused, skip it.
		 */
		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
			ptr += be16_to_cpu(dup->length);
			continue;
		}
        
		dep = (xfs_dir2_data_entry_t *)ptr;
        
		/*
		 * Bump pointer for the next iteration.
		 */
		ptr += xfs_dir2_data_entsize(dep->namelen);
		/*
		 * The entry is before the desired starting point, skip it.
		 */
		if ((char *)dep - (char *)block < wantoff)
			continue;
        
		cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
                                          (char *)dep - (char *)block);
        
		/*
		 * If it didn't fit, set the final offset to here & return.
		 */
		if (filldir(dirent, (char *)dep->name, dep->namelen,
                    cook & 0x7fffffff, be64_to_cpu(dep->inumber),
                    DT_UNKNOWN)) {
			*offset = cook & 0x7fffffff;
			xfs_da_brelse(NULL, bp);
			return 0;
		}
	}
    
	/*
	 * Reached the end of the block.
	 * Set the offset to a non-existent block 1 and return.
	 */
	*offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
    0x7fffffff;
	xfs_da_brelse(NULL, bp);
	return 0;
}
Exemplo n.º 4
0
/*
 * Getdents (readdir) for leaf and node directories.
 * This reads the data blocks only, so is the same for both forms.
 */
int						/* error */
xfs_dir2_leaf_getdents(
                       xfs_inode_t		*dp,		/* incore directory inode */
                       void			*dirent,
                       size_t			bufsize,
                       xfs_off_t		*offset,
                       filldir_t		filldir)
{
	xfs_dabuf_t		*bp;		/* data block buffer */
	int			byteoff;	/* offset in current block */
	xfs_dir2_db_t		curdb;		/* db for current block */
	xfs_dir2_off_t		curoff;		/* current overall offset */
	xfs_dir2_data_t		*data;		/* data block structure */
	xfs_dir2_data_entry_t	*dep;		/* data entry */
	xfs_dir2_data_unused_t	*dup;		/* unused entry */
	int			error = 0;	/* error return value */
	int			i;		/* temporary loop index */
	int			j;		/* temporary loop index */
	int			length;		/* temporary length value */
	xfs_bmbt_irec_t		*map;		/* map vector for blocks */
	xfs_extlen_t		map_blocks;	/* number of fsbs in map */
	xfs_dablk_t		map_off;	/* last mapped file offset */
	int			map_size;	/* total entries in *map */
	int			map_valid;	/* valid entries in *map */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_dir2_off_t		newoff;		/* new curoff after new blk */
	int			nmap;		/* mappings to ask xfs_bmapi */
	char			*ptr = NULL;	/* pointer to current data */
	int			ra_current;	/* number of read-ahead blks */
	int			ra_index;	/* *map index for read-ahead */
	int			ra_offset;	/* map entry offset for ra */
	int			ra_want;	/* readahead count wanted */
    
	/*
	 * If the offset is at or past the largest allowed value,
	 * give up right away.
	 */
	if (*offset >= XFS_DIR2_MAX_DATAPTR)
		return 0;
    
	mp = dp->i_mount;
    
	/*
	 * Set up to bmap a number of blocks based on the caller's
	 * buffer size, the directory block size, and the filesystem
	 * block size.
	 */
	map_size = howmany(bufsize + mp->m_dirblksize, mp->m_sb.sb_blocksize);
	map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP);
	map_valid = ra_index = ra_offset = ra_current = map_blocks = 0;
	bp = NULL;
    
	/*
	 * Inside the loop we keep the main offset value as a byte offset
	 * in the directory file.
	 */
	curoff = xfs_dir2_dataptr_to_byte(mp, *offset);
    
	/*
	 * Force this conversion through db so we truncate the offset
	 * down to get the start of the data block.
	 */
	map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff));
	/*
	 * Loop over directory entries until we reach the end offset.
	 * Get more blocks and readahead as necessary.
	 */
	while (curoff < XFS_DIR2_LEAF_OFFSET) {
		/*
		 * If we have no buffer, or we're off the end of the
		 * current buffer, need to get another one.
		 */
		if (!bp || ptr >= (char *)bp->data + mp->m_dirblksize) {
			/*
			 * If we have a buffer, we need to release it and
			 * take it out of the mapping.
			 */
			if (bp) {
				xfs_da_brelse(NULL, bp);
				bp = NULL;
				map_blocks -= mp->m_dirblkfsbs;
				/*
				 * Loop to get rid of the extents for the
				 * directory block.
				 */
				for (i = mp->m_dirblkfsbs; i > 0; ) {
					j = MIN((int)map->br_blockcount, i);
					map->br_blockcount -= j;
					map->br_startblock += j;
					map->br_startoff += j;
					/*
					 * If mapping is done, pitch it from
					 * the table.
					 */
					if (!map->br_blockcount && --map_valid)
						memmove(&map[0], &map[1],
                                sizeof(map[0]) *
                                map_valid);
					i -= j;
				}
			}
			/*
			 * Recalculate the readahead blocks wanted.
			 */
			ra_want = howmany(bufsize + mp->m_dirblksize,
                              mp->m_sb.sb_blocksize) - 1;
			ASSERT(ra_want >= 0);
            
			/*
			 * If we don't have as many as we want, and we haven't
			 * run out of data blocks, get some more mappings.
			 */
			if (1 + ra_want > map_blocks &&
			    map_off <
			    xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) {
				/*
				 * Get more bmaps, fill in after the ones
				 * we already have in the table.
				 */
				nmap = map_size - map_valid;
				error = xfs_bmapi(NULL, dp,
                                  map_off,
                                  xfs_dir2_byte_to_da(mp,
                                                      XFS_DIR2_LEAF_OFFSET) - map_off,
                                  XFS_BMAPI_METADATA, NULL, 0,
                                  &map[map_valid], &nmap, NULL, NULL);
				/*
				 * Don't know if we should ignore this or
				 * try to return an error.
				 * The trouble with returning errors
				 * is that readdir will just stop without
				 * actually passing the error through.
				 */
				if (error)
					break;	/* XXX */
				/*
				 * If we got all the mappings we asked for,
				 * set the final map offset based on the
				 * last bmap value received.
				 * Otherwise, we've reached the end.
				 */
				if (nmap == map_size - map_valid)
					map_off =
					map[map_valid + nmap - 1].br_startoff +
					map[map_valid + nmap - 1].br_blockcount;
				else
					map_off =
                    xfs_dir2_byte_to_da(mp,
                                        XFS_DIR2_LEAF_OFFSET);
				/*
				 * Look for holes in the mapping, and
				 * eliminate them.  Count up the valid blocks.
				 */
				for (i = map_valid; i < map_valid + nmap; ) {
					if (map[i].br_startblock ==
					    HOLESTARTBLOCK) {
						nmap--;
						length = map_valid + nmap - i;
						if (length)
							memmove(&map[i],
                                    &map[i + 1],
                                    sizeof(map[i]) *
                                    length);
					} else {
						map_blocks +=
                        map[i].br_blockcount;
						i++;
					}
				}
				map_valid += nmap;
			}
			/*
			 * No valid mappings, so no more data blocks.
			 */
			if (!map_valid) {
				curoff = xfs_dir2_da_to_byte(mp, map_off);
				break;
			}
			/*
			 * Read the directory block starting at the first
			 * mapping.
			 */
			curdb = xfs_dir2_da_to_db(mp, map->br_startoff);
			error = xfs_da_read_buf(NULL, dp, map->br_startoff,
                                    map->br_blockcount >= mp->m_dirblkfsbs ?
                                    XFS_FSB_TO_DADDR(mp, map->br_startblock) :
                                    -1,
                                    &bp, XFS_DATA_FORK);
			/*
			 * Should just skip over the data block instead
			 * of giving up.
			 */
			if (error)
				break;	/* XXX */
			/*
			 * Adjust the current amount of read-ahead: we just
			 * read a block that was previously ra.
			 */
			if (ra_current)
				ra_current -= mp->m_dirblkfsbs;
			/*
			 * Do we need more readahead?
			 */
			for (ra_index = ra_offset = i = 0;
			     ra_want > ra_current && i < map_blocks;
			     i += mp->m_dirblkfsbs) {
				ASSERT(ra_index < map_valid);
				/*
				 * Read-ahead a contiguous directory block.
				 */
				if (i > ra_current &&
				    map[ra_index].br_blockcount >=
				    mp->m_dirblkfsbs) {
                    //TODO: make sure this is right, should readahead be 
                    //replaced by readbuf?
					//xfs_buf_readahead(mp->m_ddev_targp,
                    //                  XFS_FSB_TO_DADDR(mp,
                    //                                   map[ra_index].br_startblock +
                    //                                   ra_offset),
                    //                  (int)BTOBB(mp->m_dirblksize));
                    //TODO: figure out flags, flags =0
					//libxfs_readbuf(mp->m_dev,
                    //               XFS_FSB_TO_DADDR(mp,
                    //                                map[ra_index].br_startblock +
                    //                                ra_offset),
                    //               (int)BTOBB(mp->m_dirblksize), 0);
					ra_current = i;
				}
				/*
				 * Read-ahead a non-contiguous directory block.
				 * This doesn't use our mapping, but this
				 * is a very rare case.
				 */
				else if (i > ra_current) {
					(void)xfs_da_reada_buf(NULL, dp,
                                           map[ra_index].br_startoff +
                                           ra_offset, XFS_DATA_FORK);
					ra_current = i;
				}
				/*
				 * Advance offset through the mapping table.
				 */
				for (j = 0; j < mp->m_dirblkfsbs; j++) {
					/*
					 * The rest of this extent but not
					 * more than a dir block.
					 */
					length = MIN(mp->m_dirblkfsbs,
                                 (int)(map[ra_index].br_blockcount -
                                       ra_offset));
					j += length;
					ra_offset += length;
					/*
					 * Advance to the next mapping if
					 * this one is used up.
					 */
					if (ra_offset ==
					    map[ra_index].br_blockcount) {
						ra_offset = 0;
						ra_index++;
					}
				}
			}
			/*
			 * Having done a read, we need to set a new offset.
			 */
			newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0);
			/*
			 * Start of the current block.
			 */
			if (curoff < newoff)
				curoff = newoff;
			/*
			 * Make sure we're in the right block.
			 */
			else if (curoff > newoff)
				ASSERT(xfs_dir2_byte_to_db(mp, curoff) ==
				       curdb);
			data = bp->data;
			xfs_dir2_data_check(dp, bp);
			/*
			 * Find our position in the block.
			 */
			ptr = (char *)&data->u;
			byteoff = xfs_dir2_byte_to_off(mp, curoff);
			/*
			 * Skip past the header.
			 */
			if (byteoff == 0)
				curoff += (uint)sizeof(data->hdr);
			/*
			 * Skip past entries until we reach our offset.
			 */
			else {
				while ((char *)ptr - (char *)data < byteoff) {
					dup = (xfs_dir2_data_unused_t *)ptr;
                    
					if (be16_to_cpu(dup->freetag)
                        == XFS_DIR2_DATA_FREE_TAG) {
                        
						length = be16_to_cpu(dup->length);
						ptr += length;
						continue;
					}
					dep = (xfs_dir2_data_entry_t *)ptr;
					length =
                    xfs_dir2_data_entsize(dep->namelen);
					ptr += length;
				}
				/*
				 * Now set our real offset.
				 */
				curoff =
                xfs_dir2_db_off_to_byte(mp,
                                        xfs_dir2_byte_to_db(mp, curoff),
                                        (char *)ptr - (char *)data);
				if (ptr >= (char *)data + mp->m_dirblksize) {
					continue;
				}
			}
		}
		/*
		 * We have a pointer to an entry.
		 * Is it a live one?
		 */
		dup = (xfs_dir2_data_unused_t *)ptr;
		/*
		 * No, it's unused, skip over it.
		 */
		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
			length = be16_to_cpu(dup->length);
			ptr += length;
			curoff += length;
			continue;
		}
        
		dep = (xfs_dir2_data_entry_t *)ptr;
		length = xfs_dir2_data_entsize(dep->namelen);
        
		if (filldir(dirent, (char *)dep->name, dep->namelen,
                    xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff,
                    be64_to_cpu(dep->inumber), DT_UNKNOWN))
			break;
        
		/*
		 * Advance to next entry in the block.
		 */
		ptr += length;
		curoff += length;
		/* bufsize may have just been a guess; don't go negative */
		bufsize = bufsize > length ? bufsize - length : 0;
	}
    
	/*
	 * All done.  Set output offset value to current offset.
	 */
	if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR))
		*offset = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
	else
		*offset = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff;
	kmem_free(map);
	if (bp)
		xfs_da_brelse(NULL, bp);
	return error;
}
Exemplo n.º 5
0
/*
 * Add an entry to a block directory.
 */
int						/* error */
xfs_dir2_block_addname(
	xfs_da_args_t		*args)		/* directory op arguments */
{
	xfs_dir2_data_free_t	*bf;		/* bestfree table in block */
	xfs_dir2_block_t	*block;		/* directory block structure */
	xfs_dir2_leaf_entry_t	*blp;		/* block leaf entries */
	xfs_dabuf_t		*bp;		/* buffer for block */
	xfs_dir2_block_tail_t	*btp;		/* block tail */
	int			compact;	/* need to compact leaf ents */
	xfs_dir2_data_entry_t	*dep;		/* block data entry */
	xfs_inode_t		*dp;		/* directory inode */
	xfs_dir2_data_unused_t	*dup;		/* block unused entry */
	int			error;		/* error return value */
	xfs_dir2_data_unused_t	*enddup=NULL;	/* unused at end of data */
	xfs_dahash_t		hash;		/* hash value of found entry */
	int			high;		/* high index for binary srch */
	int			highstale;	/* high stale index */
	int			lfloghigh=0;	/* last final leaf to log */
	int			lfloglow=0;	/* first final leaf to log */
	int			len;		/* length of the new entry */
	int			low;		/* low index for binary srch */
	int			lowstale;	/* low stale index */
	int			mid=0;		/* midpoint for binary srch */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			needlog;	/* need to log header */
	int			needscan;	/* need to rescan freespace */
	__be16			*tagp;		/* pointer to tag value */
	xfs_trans_t		*tp;		/* transaction structure */

	trace_xfs_dir2_block_addname(args);

	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	/*
	 * Read the (one and only) directory block into dabuf bp.
	 */
	if ((error =
	    xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
		return error;
	}
	ASSERT(bp != NULL);
	block = bp->data;
	/*
	 * Check the magic number, corrupted if wrong.
	 */
	if (unlikely(be32_to_cpu(block->hdr.magic) != XFS_DIR2_BLOCK_MAGIC)) {
		XFS_CORRUPTION_ERROR("xfs_dir2_block_addname",
				     XFS_ERRLEVEL_LOW, mp, block);
		xfs_da_brelse(tp, bp);
		return XFS_ERROR(EFSCORRUPTED);
	}
	len = xfs_dir2_data_entsize(args->namelen);
	/*
	 * Set up pointers to parts of the block.
	 */
	bf = block->hdr.bestfree;
	btp = xfs_dir2_block_tail_p(mp, block);
	blp = xfs_dir2_block_leaf_p(btp);
	/*
	 * No stale entries?  Need space for entry and new leaf.
	 */
	if (!btp->stale) {
		/*
		 * Tag just before the first leaf entry.
		 */
		tagp = (__be16 *)blp - 1;
		/*
		 * Data object just before the first leaf entry.
		 */
		enddup = (xfs_dir2_data_unused_t *)((char *)block + be16_to_cpu(*tagp));
		/*
		 * If it's not free then can't do this add without cleaning up:
		 * the space before the first leaf entry needs to be free so it
		 * can be expanded to hold the pointer to the new entry.
		 */
		if (be16_to_cpu(enddup->freetag) != XFS_DIR2_DATA_FREE_TAG)
			dup = enddup = NULL;
		/*
		 * Check out the biggest freespace and see if it's the same one.
		 */
		else {
			dup = (xfs_dir2_data_unused_t *)
			      ((char *)block + be16_to_cpu(bf[0].offset));
			if (dup == enddup) {
				/*
				 * It is the biggest freespace, is it too small
				 * to hold the new leaf too?
				 */
				if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) {
					/*
					 * Yes, we use the second-largest
					 * entry instead if it works.
					 */
					if (be16_to_cpu(bf[1].length) >= len)
						dup = (xfs_dir2_data_unused_t *)
						      ((char *)block +
						       be16_to_cpu(bf[1].offset));
					else
						dup = NULL;
				}
			} else {
				/*
				 * Not the same free entry,
				 * just check its length.
				 */
				if (be16_to_cpu(dup->length) < len) {
					dup = NULL;
				}
			}
		}
		compact = 0;
	}
	/*
	 * If there are stale entries we'll use one for the leaf.
	 * Is the biggest entry enough to avoid compaction?
	 */
	else if (be16_to_cpu(bf[0].length) >= len) {
		dup = (xfs_dir2_data_unused_t *)
		      ((char *)block + be16_to_cpu(bf[0].offset));
		compact = 0;
	}
	/*
	 * Will need to compact to make this work.
	 */
	else {
		/*
		 * Tag just before the first leaf entry.
		 */
		tagp = (__be16 *)blp - 1;
		/*
		 * Data object just before the first leaf entry.
		 */
		dup = (xfs_dir2_data_unused_t *)((char *)block + be16_to_cpu(*tagp));
		/*
		 * If it's not free then the data will go where the
		 * leaf data starts now, if it works at all.
		 */
		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
			if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) *
			    (uint)sizeof(*blp) < len)
				dup = NULL;
		} else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len)
			dup = NULL;
		else
			dup = (xfs_dir2_data_unused_t *)blp;
		compact = 1;
	}
	/*
	 * If this isn't a real add, we're done with the buffer.
	 */
	if (args->op_flags & XFS_DA_OP_JUSTCHECK)
		xfs_da_brelse(tp, bp);
	/*
	 * If we don't have space for the new entry & leaf ...
	 */
	if (!dup) {
		/*
		 * Not trying to actually do anything, or don't have
		 * a space reservation: return no-space.
		 */
		if ((args->op_flags & XFS_DA_OP_JUSTCHECK) || args->total == 0)
			return XFS_ERROR(ENOSPC);
		/*
		 * Convert to the next larger format.
		 * Then add the new entry in that format.
		 */
		error = xfs_dir2_block_to_leaf(args, bp);
		xfs_da_buf_done(bp);
		if (error)
			return error;
		return xfs_dir2_leaf_addname(args);
	}
	/*
	 * Just checking, and it would work, so say so.
	 */
	if (args->op_flags & XFS_DA_OP_JUSTCHECK)
		return 0;
	needlog = needscan = 0;
	/*
	 * If need to compact the leaf entries, do it now.
	 * Leave the highest-numbered stale entry stale.
	 * XXX should be the one closest to mid but mid is not yet computed.
	 */
	if (compact) {
		int	fromidx;		/* source leaf index */
		int	toidx;			/* target leaf index */

		for (fromidx = toidx = be32_to_cpu(btp->count) - 1,
			highstale = lfloghigh = -1;
		     fromidx >= 0;
		     fromidx--) {
			if (be32_to_cpu(blp[fromidx].address) == XFS_DIR2_NULL_DATAPTR) {
				if (highstale == -1)
					highstale = toidx;
				else {
					if (lfloghigh == -1)
						lfloghigh = toidx;
					continue;
				}
			}
			if (fromidx < toidx)
				blp[toidx] = blp[fromidx];
			toidx--;
		}
		lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1);
		lfloghigh -= be32_to_cpu(btp->stale) - 1;
		be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1));
		xfs_dir2_data_make_free(tp, bp,
			(xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
			(xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)),
			&needlog, &needscan);
		blp += be32_to_cpu(btp->stale) - 1;
		btp->stale = cpu_to_be32(1);
		/*
		 * If we now need to rebuild the bestfree map, do so.
		 * This needs to happen before the next call to use_free.
		 */
		if (needscan) {
			xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
			needscan = 0;
		}
	}
	/*
	 * Set leaf logging boundaries to impossible state.
	 * For the no-stale case they're set explicitly.
	 */
	else if (btp->stale) {
		lfloglow = be32_to_cpu(btp->count);
		lfloghigh = -1;
	}
	/*
	 * Find the slot that's first lower than our hash value, -1 if none.
	 */
	for (low = 0, high = be32_to_cpu(btp->count) - 1; low <= high; ) {
		mid = (low + high) >> 1;
		if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
			break;
		if (hash < args->hashval)
			low = mid + 1;
		else
			high = mid - 1;
	}
	while (mid >= 0 && be32_to_cpu(blp[mid].hashval) >= args->hashval) {
		mid--;
	}
	/*
	 * No stale entries, will use enddup space to hold new leaf.
	 */
	if (!btp->stale) {
		/*
		 * Mark the space needed for the new leaf entry, now in use.
		 */
		xfs_dir2_data_use_free(tp, bp, enddup,
			(xfs_dir2_data_aoff_t)
			((char *)enddup - (char *)block + be16_to_cpu(enddup->length) -
			 sizeof(*blp)),
			(xfs_dir2_data_aoff_t)sizeof(*blp),
			&needlog, &needscan);
		/*
		 * Update the tail (entry count).
		 */
		be32_add_cpu(&btp->count, 1);
		/*
		 * If we now need to rebuild the bestfree map, do so.
		 * This needs to happen before the next call to use_free.
		 */
		if (needscan) {
			xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block,
				&needlog);
			needscan = 0;
		}
		/*
		 * Adjust pointer to the first leaf entry, we're about to move
		 * the table up one to open up space for the new leaf entry.
		 * Then adjust our index to match.
		 */
		blp--;
		mid++;
		if (mid)
			memmove(blp, &blp[1], mid * sizeof(*blp));
		lfloglow = 0;
		lfloghigh = mid;
	}
	/*
	 * Use a stale leaf for our new entry.
	 */
	else {
		for (lowstale = mid;
		     lowstale >= 0 &&
			be32_to_cpu(blp[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
		     lowstale--)
			continue;
		for (highstale = mid + 1;
		     highstale < be32_to_cpu(btp->count) &&
			be32_to_cpu(blp[highstale].address) != XFS_DIR2_NULL_DATAPTR &&
			(lowstale < 0 || mid - lowstale > highstale - mid);
		     highstale++)
			continue;
		/*
		 * Move entries toward the low-numbered stale entry.
		 */
		if (lowstale >= 0 &&
		    (highstale == be32_to_cpu(btp->count) ||
		     mid - lowstale <= highstale - mid)) {
			if (mid - lowstale)
				memmove(&blp[lowstale], &blp[lowstale + 1],
					(mid - lowstale) * sizeof(*blp));
			lfloglow = MIN(lowstale, lfloglow);
			lfloghigh = MAX(mid, lfloghigh);
		}
		/*
		 * Move entries toward the high-numbered stale entry.
		 */
		else {
			ASSERT(highstale < be32_to_cpu(btp->count));
			mid++;
			if (highstale - mid)
				memmove(&blp[mid + 1], &blp[mid],
					(highstale - mid) * sizeof(*blp));
			lfloglow = MIN(mid, lfloglow);
			lfloghigh = MAX(highstale, lfloghigh);
		}
		be32_add_cpu(&btp->stale, -1);
	}
	/*
	 * Point to the new data entry.
	 */
	dep = (xfs_dir2_data_entry_t *)dup;
	/*
	 * Fill in the leaf entry.
	 */
	blp[mid].hashval = cpu_to_be32(args->hashval);
	blp[mid].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
				(char *)dep - (char *)block));
	xfs_dir2_block_log_leaf(tp, bp, lfloglow, lfloghigh);
	/*
	 * Mark space for the data entry used.
	 */
	xfs_dir2_data_use_free(tp, bp, dup,
		(xfs_dir2_data_aoff_t)((char *)dup - (char *)block),
		(xfs_dir2_data_aoff_t)len, &needlog, &needscan);
	/*
	 * Create the new data entry.
	 */
	dep->inumber = cpu_to_be64(args->inumber);
	dep->namelen = args->namelen;
	memcpy(dep->name, args->name, args->namelen);
	tagp = xfs_dir2_data_entry_tag_p(dep);
	*tagp = cpu_to_be16((char *)dep - (char *)block);
	/*
	 * Clean up the bestfree array and log the header, tail, and entry.
	 */
	if (needscan)
		xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
	if (needlog)
		xfs_dir2_data_log_header(tp, bp);
	xfs_dir2_block_log_tail(tp, bp);
	xfs_dir2_data_log_entry(tp, bp, dep);
	xfs_dir2_data_check(dp, bp);
	xfs_da_buf_done(bp);
	return 0;
}
Exemplo n.º 6
0
/*
 * Internal block lookup routine.
 */
static int					/* error */
xfs_dir2_block_lookup_int(
	xfs_da_args_t		*args,		/* dir lookup arguments */
	xfs_dabuf_t		**bpp,		/* returned block buffer */
	int			*entno)		/* returned entry number */
{
	xfs_dir2_dataptr_t	addr;		/* data entry address */
	xfs_dir2_block_t	*block;		/* block structure */
	xfs_dir2_leaf_entry_t	*blp;		/* block leaf entries */
	xfs_dabuf_t		*bp;		/* block buffer */
	xfs_dir2_block_tail_t	*btp;		/* block tail */
	xfs_dir2_data_entry_t	*dep;		/* block data entry */
	xfs_inode_t		*dp;		/* incore inode */
	int			error;		/* error return value */
	xfs_dahash_t		hash;		/* found hash value */
	int			high;		/* binary search high index */
	int			low;		/* binary search low index */
	int			mid;		/* binary search current idx */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_trans_t		*tp;		/* transaction pointer */
	enum xfs_dacmp		cmp;		/* comparison result */

	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	/*
	 * Read the buffer, return error if we can't get it.
	 */
	if ((error =
	    xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
		return error;
	}
	ASSERT(bp != NULL);
	block = bp->data;
	xfs_dir2_data_check(dp, bp);
	btp = xfs_dir2_block_tail_p(mp, block);
	blp = xfs_dir2_block_leaf_p(btp);
	/*
	 * Loop doing a binary search for our hash value.
	 * Find our entry, ENOENT if it's not there.
	 */
	for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) {
		ASSERT(low <= high);
		mid = (low + high) >> 1;
		if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
			break;
		if (hash < args->hashval)
			low = mid + 1;
		else
			high = mid - 1;
		if (low > high) {
			ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
			xfs_da_brelse(tp, bp);
			return XFS_ERROR(ENOENT);
		}
	}
	/*
	 * Back up to the first one with the right hash value.
	 */
	while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) {
		mid--;
	}
	/*
	 * Now loop forward through all the entries with the
	 * right hash value looking for our name.
	 */
	do {
		if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR)
			continue;
		/*
		 * Get pointer to the entry from the leaf.
		 */
		dep = (xfs_dir2_data_entry_t *)
			((char *)block + xfs_dir2_dataptr_to_off(mp, addr));
		/*
		 * Compare name and if it's an exact match, return the index
		 * and buffer. If it's the first case-insensitive match, store
		 * the index and buffer and continue looking for an exact match.
		 */
		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
			args->cmpresult = cmp;
			*bpp = bp;
			*entno = mid;
			if (cmp == XFS_CMP_EXACT)
				return 0;
		}
	} while (++mid < be32_to_cpu(btp->count) &&
			be32_to_cpu(blp[mid].hashval) == hash);

	ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
	/*
	 * Here, we can only be doing a lookup (not a rename or replace).
	 * If a case-insensitive match was found earlier, return success.
	 */
	if (args->cmpresult == XFS_CMP_CASE)
		return 0;
	/*
	 * No match, release the buffer and return ENOENT.
	 */
	xfs_da_brelse(tp, bp);
	return XFS_ERROR(ENOENT);
}
Exemplo n.º 7
0
/*
 * Internal block lookup routine.
 */
static int					/* error */
xfs_dir2_block_lookup_int(
	xfs_da_args_t		*args,		/* dir lookup arguments */
	xfs_dabuf_t		**bpp,		/* returned block buffer */
	int			*entno)		/* returned entry number */
{
	xfs_dir2_dataptr_t	addr;		/* data entry address */
	xfs_dir2_block_t	*block;		/* block structure */
	xfs_dir2_leaf_entry_t	*blp;		/* block leaf entries */
	xfs_dabuf_t		*bp;		/* block buffer */
	xfs_dir2_block_tail_t	*btp;		/* block tail */
	xfs_dir2_data_entry_t	*dep;		/* block data entry */
	xfs_inode_t		*dp;		/* incore inode */
	int			error;		/* error return value */
	xfs_dahash_t		hash;		/* found hash value */
	int			high;		/* binary search high index */
	int			low;		/* binary search low index */
	int			mid;		/* binary search current idx */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_trans_t		*tp;		/* transaction pointer */

	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	/*
	 * Read the buffer, return error if we can't get it.
	 */
	if ((error =
	    xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
		return error;
	}
	ASSERT(bp != NULL);
	block = bp->data;
	xfs_dir2_data_check(dp, bp);
	btp = xfs_dir2_block_tail_p(mp, block);
	blp = xfs_dir2_block_leaf_p(btp);
	/*
	 * Loop doing a binary search for our hash value.
	 * Find our entry, ENOENT if it's not there.
	 */
	for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) {
		ASSERT(low <= high);
		mid = (low + high) >> 1;
		if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
			break;
		if (hash < args->hashval)
			low = mid + 1;
		else
			high = mid - 1;
		if (low > high) {
			ASSERT(args->oknoent);
			xfs_da_brelse(tp, bp);
			return XFS_ERROR(ENOENT);
		}
	}
	/*
	 * Back up to the first one with the right hash value.
	 */
	while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) {
		mid--;
	}
	/*
	 * Now loop forward through all the entries with the
	 * right hash value looking for our name.
	 */
	do {
		if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR)
			continue;
		/*
		 * Get pointer to the entry from the leaf.
		 */
		dep = (xfs_dir2_data_entry_t *)
			((char *)block + xfs_dir2_dataptr_to_off(mp, addr));
		/*
		 * Compare, if it's right give back buffer & entry number.
		 */
		if (dep->namelen == args->namelen &&
		    dep->name[0] == args->name[0] &&
		    memcmp(dep->name, args->name, args->namelen) == 0) {
			*bpp = bp;
			*entno = mid;
			return 0;
		}
	} while (++mid < be32_to_cpu(btp->count) && be32_to_cpu(blp[mid].hashval) == hash);
	/*
	 * No match, release the buffer and return ENOENT.
	 */
	ASSERT(args->oknoent);
	xfs_da_brelse(tp, bp);
	return XFS_ERROR(ENOENT);
}